Antioxidant Activity of Panax ginseng to Regulate ROS in Various Chronic Diseases

Abstract

Reactive oxygen species (ROS)-the byproduct of regular cell activity formed by various cellular components—play a significant role in pathological and physiological conditions. Alternatively, antioxidants are compounds that reduce or scavenge reactive species in cells. An asymmetry between the antioxidant defense system and ROS from intracellular and extracellular sources cause chronic diseases such as cancer, inflammation, tumorigenesis, cardiovascular and neurogenerative diseases. However, Panax ginseng and its secondary metabolites (known as ginsenosides, phenolic compounds, peptides, acid polysaccharides, polyacetylene, and alkaloids) are well-recognized as antioxidants in many in vitro and in vivo experiments which show beneficial activity in regulating ROS in these diseases. There are extensive evidences that P. ginseng can destroy cancer cells specifically by increasing oxidative stress through ROS generation without significantly harming normal cells. Additionally, numerous studies have examined the antioxidant activity of ginseng and its derivatives on ROS-mediated signaling pathways which are discussed herein. This review summarizes the potential antioxidant activity of P. ginseng in several chronic diseases, and gives updated research evidence with related mechanisms and the future possibilities of nano-formulated compounds of P. ginseng and other polyphenols.

1. Introduction

Ginseng comes from the genus Panax of the Araliaceae family with nine different species such as Panax ginseng (Korean ginseng), Panax notoginseng (Chinese ginseng), Panax japonicum (Japanese ginseng), and Panax quinquefolius (American ginseng) [1]. Among all ginseng, four types of P. ginseng can be categorized according to how they are processed, for example, fresh ginseng, white ginseng (air-dried), red ginseng (steamed), and sun ginseng [2]. The word “ginseng” is derived from the Chinese word “rénshēn” which means “human” as the roots of ginseng are shaped like the human leg [3]. Ginseng has long been recognized as ‘the king of herbs’ due to its ability to improve fitness and relax the mind [4]. P. ginseng is endemic to Korea and China and has been used in traditional treatment [5]. However, consumers from Korea and others prefer Korean ginseng due to its current medical research findings of being useful in boosting blood circulation and better cognition, acting as a mind booster, and it being supposed to bolster one’s soul, increase the body’s immune system, and control diabetes, along with possessing anti-aging and anticancer properties [6,7]. P. ginseng contains a vast amount of secondary metabolites such as phenolic acids (gallic acid, caffeic acid, coumaric acid, salicylic acid, cinnamic acid, maltol, etc.), flavonoids, acid polysaccharides, amino acids, phytosterol, carbohydrates, minerals, ginseng oil, and certain vitamins [4,8]. P. ginseng has attracted the interest of researchers worldwide due to its pharmacological efficacy and potent medical applications.

Instead of entire ginseng and other components, a majority of researches have been conducted on specific ginsenosides to treat a variety of medical problems [9]. Ginsenosides are mainly triterpene saponins of ginseng. To date, more than 218 ginsenosides (major types: Rc, Rb1, Rb2, Rg1, Rd, and Re; minor types: Rh1, Rh2, and Rg3) have been identified from different parts of ginseng (leaves, roots, berries, and flower buds) and these metabolites have become popular for research. Ginsenosides are the therapeutically active components obtained from ginseng and are widely recognized for their oxidative stress [10], apoptosis [11], inflammation [12], angiogenesis [13], anticancer [14], and cancer metastatic properties associated with cell proliferation. Ginsenosides are divided into two groups based on the glycon structure: oleanane and dammarane [15]. According to the chemical structure, dammarane-type ginsenosides can be further classified into two categories: protopanaxadiol (PPD) and protopanaxatriol (PPT) [16], whereas the minor categories depending on aglycone moieties include ocotillol and oleanane [17]. Ginsenosides Rc, Rb2, Rh2, Rg3, Rh4, Ck, Rk1, Rk3, and Rd are strong bioactive components that have been shown to greatly inhibit the proliferation of cancer cells by regulating ROS in mitochondria [18]. The following are listed in decreasing order of how well ginsenosides scavenge intracellular ROS: Rb2 > Rc > Rg2 > Rh2 > Rh1 > Rf > Rg3 > Rg1 > Rb1 > Re > Rd [19]. Different studies have shown that the transformation of ginseng referred to as ginsenosides have stronger activity than crude ginseng [20].

P. ginseng and ginsenosides have excellent ROS-regulating activity in various disease families such as sensor impairment, cardiovascular diseases, neurogenerative diseases, cancer, diabetes, inflammation, and vice-versa. This review was designed to investigate the antioxidant properties of P. ginseng and ginsenosides regulating ROS in different chronic diseases.

2. Research Methodology

Existing knowledge was incorporated to prepare a review on the ROS-regulating activity of P. ginseng and its secondary metabolites in different chronic diseases. The relevant information was gathered by looking through articles published in the MDPI, Elsevier, Taylor and Francis, Wiley, Springer, Google Scholar, PubMed, and NCBI databases between 1996 and January 2023.

3. ROS, Oxidative Stress, and Antioxidants

Reactive oxygen species (ROS) including hydrogen peroxide (H₂O₂), superoxide (O₂∙), and hydroxyl (HO∙) radicals were initially recognized as potentially hazardous by-products; they are now acknowledged to serve significant roles as secondary messengers in numerous intercellular pathways [21]. ROS are produced during ATP production by the electron transport chain and NADPH (nicotinamide adenine dinucleotide phosphate) oxidase system [22]. Moreover, our bodies usually produce huge amounts of ROS due to our daily lifestyles including extended working circumstances, sitting for a long time, wearing restrictive clothing, using illicit substances often, eating unhealthily, and smoking or drinking too much alcohol [23]. ROS positively impact on immunological activity and intracellular signaling at mild to moderate levels [24]. A higher concentration of ROS can cause oxidative stress, DNA damage, redox homeostasis, tumor progression, and drug resistance which are related to the development of various diseases. ROS play a crucial role in cell proliferation, differentiation, and the control of signal transduction at certain levels (Figure 1) [22]. According to Sies (1985), “Oxidative stress is defined as the imbalance of pro-oxidant and the antioxidant protective capacity that promotes ROS or RNS which might cause potential damage” [25]. Undeniably, oxidative stress is associated with more than 100 diseases as a source or outcome [26,27]. It is well known that oxidative stress leads to cell death by damaging important bio-compounds such as proteins, DNA, and lipids [28]. Oxidative stress acts as a contributor to many chronic diseases such as cancer, neuro-generative disease, inflammation, cardiovascular disease, etc. [29].

On the other hand, an antioxidant is a compound that reduces or scavenges reactive species or blocks the oxidation in cells [30]. In other words, antioxidants have the power to stop or delay the oxidation reaction to regulate the excessive production of oxidants [31]. Thiols and polyphenols are common examples of antioxidants for their reducing behavior [32]. Plants and animals consist of two types of antioxidants: non-enzymatic (vitamin E, C, carotenoids, lipoic acid, and others) and enzymatic (catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), Glutathione-S-Transferase (GST), Glutathione reductase (GR), etc.). These enzymatic antioxidants have important functions in regulating cell homeostasis [33]. In a nutshell, the antioxidant mechanisms are (a) inhibiting the production of reactive species, (b) scavenging oxidants, (c) restoring the damaged molecule, (d) blocking the formation of harmful secondary metabolites and inflammation mediators, and (e) developing and boosting the natural antioxidant defense system. These defensive mechanisms work together to prevent oxidative stress in the body [34]. However, in redox biology, superoxide dismutase quickly turns into H₂O₂ and O₂ via the SOD enzyme. The Fenton reaction can decrease metal ions to produce OH^. from H₂O₂, which is issued in systemic inflammation [35,36]. OH^. are reactive and so damages macromolecules. Antioxidant enzymes (catalase, glutathione peroxidase) can detoxify H₂O₂ to avoid the production of OH^. (Figure 2).

Natural antioxidants have numerous biological effects including preventing ROS production and inhibiting free radicals [37]. The administration of natural sources of an antioxidant such as ginseng, pomegranate, curcumin, sesame, garlic, peppermint, and olive leaves demonstrated beneficial effects on ROS-mediated diseases in both animal and human studies [38,39].

4. Pathways Related to Oxidative Stress in Cells

There are multiple mechanisms involved in the normal cellular process. These mechanisms produce antioxidant enzymes such as SOD, CAT, GPx, HO-1, and G-S-T to inhibit the production of ROS which protect the cell from damage by maintaining antioxidant/oxidation balance [20]. Several pathways including NF-κB, Keap1/Nrf2/ARE, Wnt/β catenin, and PI3k/Akt are the most important for regulating the redox balance.

NF-κB is an essential nuclear transcription factor that regulates innate immunity, tumor progression, and inflammatory responses [40]. Excessive ROS production activates NF-κB by activating the MMP [41]. NF-κB is an important factor in the expression of COX-2, iNOS, and cytokines [42]. Cox-2 generates prostaglandin E2 in the cell which causes skin cancer and iNOS produces nitric oxide that leads to inflammation [43]. However, the suppression of NF-κB activity may reduce inflammation and oxidative stress [31].

The Keap1/Nrf2/ARE (kelch-like epoxychloropropqane-related protein 1/nuclear factor erythroid2-related factor 2/antioxidant response element) signaling pathway plays a vital role in the improvement in oxidative stress [44]. Nrf2 is an important transcription factor that protects the cell from oxidative stress [45]. In extreme antioxidant stress conditions, Nrf2 dissociates from keap1 and binds with the ARE which down-regulates antioxidant enzyme production, resulting in DNA damage, apoptosis, autophagy, etc. [46].

Furthermore, the Wnt signaling pathway is crucial for numerous basic processes of embryonic development and the homeostasis of normal cells [47]. The Wnt/β-catenin pathway is generally composed of β catenin, glycogen synthase kinase-3 (gsk-3), and casein kinase-1 (CK-1) proteins. In normal physiological conditions, gsk-3β and CK-1 phosphorylate β-catenin, the ligase complex of E3-ubiquitin, specifically targets β-catenin for destruction and ubiquitination. During oxidative stress, β-catenin is not decomposed, leading to the activation of the Wnt/β-catenin pathway [48].

In addition, the PI3k/Akt signaling pathway is also essential in the mechanism of oxidative stress which controls cell proliferation and cell apoptosis [49]. The stimulation of Akt activity helps to regulate apoptosis by enhancing Bcl-2 and reducing Bax and caspase-3 expression. Many researchers have shown that the PI3K/Akt signaling pathway offers antioxidative activity which inhibits apoptosis and mitigates ischemia-reperfusion injury [50]. However, excessive ROS production blocks the PI3k/Akt, resulting in tumorigenesis [51] (Figure 3).

5. Roles of P. ginseng in the Oxidative-Stress-Related Signaling Pathways

It has been reported that P. ginseng and its derivatives are some of the antioxidant-rich sources involved in the regulation of many oxidative-stress-related pathways [20]. Ginseng and ginsenosides have antioxidant activity, inhibiting oxidative stress, and their preventive effects are explained by their ability to scavenge ROS. Several in vitro and in vivo experiments have depicted that P. ginseng and ginsenosides increase antioxidant enzymes activity to inhibit ROS. P. ginseng showed a barrier role against oxidative stress in several cell lines. Furthermore, the supplementation of P. ginseng increases antioxidant enzymes and reduces the generation of ROS and MDA in various tissues such as heart, lung, kidney, and liver in animal models.

Several studies have shown that ginsenoside Rg1 can stimulate the Nrf2/ARE pathway and mitigate neuronal injury prompted by ischemia reperfusion (I/R) [52]. Rg1 prevents the inflammation and oxidative stress of diabetic rats by inducing the Keap1/Nrf2 pathway, increases the survival rate of cells, and also minimizes the excessive ROS and cell apoptosis by increasing the Nrf1/HO-1 pathway [53]. Similarly, the administration of ginsenoside Rd reduces serum CK and LDH and induces HO-1 and Nrf2 expression to protect against myocardial I/R injury [54]. In addition, by activating the Nrf2 pathway, ginsenoside Rb1 increases GSH levels and decreases MDA content. This antioxidant regulatory activity of Rb1 relieves diabetic retinopathy [55,56]. Moreover, Rb1 enhances antioxidant enzymes activity that reduce the MDA level in spinal-cord-injured (SCI) rats by stimulating the Nrf2/HO-1 signaling pathway [57]. In addition, ginsenoside Rg1 remarkably improves SOD and GSH contents, inhibits MDA production and ROS levels, and exerts antioxidant and anti-inflammatory activity via the activation of the Nrf2/HO-1 signaling pathway [58]. 20(S)-Rg3 and 20(R) compounds induce the expression of antioxidant enzymes and protect H₂O₂-mediated myocardial cell injury through the activation of the Nrf2/HO-1 pathway [59]. Along with these reports, ginsenoside Rg3 inhibits oxidative damage and apoptosis via activating Nrf2/ARE through Akt activation [60]. Ginsenoside compound K (CK) inhibits diabetic nephropathy via inhibiting ROS generation and inflammatory cytokines IL-1β through the upregulation of the NF-κB/p38 signaling pathway [61]. Both ginsenoside Rb1 and Rg1 increase the activity of catalase and reduce ROS formulation in case of inhibiting myocardial oxidation [62]. Ginsenoside Rg1 induces SOD and GSH-x enzyme activity and reduces the ROS and MDA level to attenuate oxidative-stress-mediated aging and the Wnt/β-catenin pathway.

Similarly, red ginseng (RG) also provides significant antioxidant activity in several disease cases such as diabetes, skin cancer, hepatic and nerve disorder, etc. RG enhances the antioxidant activity and reduces the oxidative stress that is exposed in

Table 1. Antioxidant activity of ginseng/ginsenosides in oxidative-stress-mediated diseases.

Diseases	Ginseng/Ginsenosides	Action	Model	References
Intestinal I/R injury	Rg1	↓ROS, ↓apoptosis ↓ROS, ↓tunnel positive cell	In vitro In vivo	[52]
Adriamycin-induced cardiotoxicity	Rg3	↓ROS, ↓MDA, ↑SOD, ↑eNOS	In vitro	[60]
Inflammation in asthma	Rg3	↑Nrf2, ↑HO-1, ↑SOD, ↑GSH, ↓MDA	In vivo/Mice	[63]
Diabetic nephropathy	CK	↓ROS, ↓IL-1β	In vivo/Mice	[61]
Myocardial cell injury	20(S)-Rg3 and 20(R)	↓ROS, ↓MDA ↑SOD, ↑GSH-Px, ↑CAT	In vitro	[59]
Myocardial ischemia-reperfusion	Rd	↓CK, ↓LDH, ↑HO-1	In vivo/Rats	[54]
Spinal cord injury	Rb1	↓MDA, ↑SOD, ↑CAT, ↑GSH	In vivo/Rats	[57]
Rat SCI model	Rg1	↓MDA, ↑SOD, ↑GSH	In vivo/Rats	[58]
Cerebral ischemia/reperfusion damage	Re	↑SOD, ↑GSH-Px, ↓MDA,	In vivo/Rats	[64]
Mitochondrial oxidation	Rb1, Rg1	↑CAT, ↑complexes I-V, ↑ATP ↓ROS	In vivo/Mice	[62]
Cerebral hypoxic-ischemic damage	Red ginseng	↑NQO1, ↑HO1, ↑SOD2, ↑Gpx1, ↓IL-1β, ↓iNOS	In vivo	[65]
Hepatic disease	Red ginseng	↓MDA, ↓DCF, ↑GPx, ↑GR, ↑CAT, ↑SOD	In vitro	[66]
Pheochromocytoma	Red ginseng	↓DCF, ↑GCLC, ↑SOD, ↑CAT ↑Nrf2, ↑HO-1	In vitro	[67]
Skin cancer	Red ginseng	↑GSH, ↑SOD, ↑CAT, ↑Vit C, ↓TBARS	In vivo/Mice	[68]
Diabetes	Red ginseng	↑GSH, ↑SOD, ↑CAT, ↑GPx, ↑GR, ↓MDA	In vivo/Mice	[69]
Aging	Red ginseng	↓MDA, ↑SOD, ↑CAT, ↑GPx, ↑GR, ↑GST		[70]
Nerve disorder	Red ginseng	↑GPx, ↓MDA, ↓ROS	In vivo/Mice	[71]
Kidney disease	Rd	↑SOD, ↑CAT, ↑GPx, ↓MDA, ↓urea nitrogen, ↓creatinine	In vivo/Rats	[72]

Notes: ↑-Increases, ↓-Decrease, abbreviations: ROS-reactive oxygen species, MDA-malondialdehyde, SOD-superoxide dismutase, Enos-endothelial nitric oxide synthase, Nrf2-nuclear factor erythroid-2-related factor 2, HO-1-Heme oxygenase-1, GSH-glutathione, IL-1β-interleukin-1β, GSH-Px-glutathione peroxidase, CAT-catalase, Ck-compound K, LDH-lactate dehydrogenase, ATP-adenosine triphosphate, NQO1-NAD(P)H quinone oxidoreductase 1, iNOS-inducible nitric oxide synthase, DCF-Deoxycoformycin, GR-glutathione reductase, GCLC-Glutamate-cysteine ligase catalytic, Vit-c-Vitamin C, TBARS-Thiobarbituric acid reactive substances, GST-glutathione-S-Transferase.

.

6. P. ginseng in ROS-Mediated Diseases

In mammalian cells, mitochondria are significant for pathophysiological processes including oxidative phosphorylation (OXPHOS), the formation of cell development, and mediating key events that determine cell functions and states. According to some reviews, many diseases such as I/R injury, cardiovascular diseases, neurogenerative diseases, cancer, and metabolic disorders have been linked to mitochondrial dysfunction [73]. Several studies have demonstrated that P. ginseng regulates mitochondrial ROS, apoptosis, dynamics, biogenesis, and mitophagy to have a pharmaceutical impact. The overexpression of mitochondrial ROS leads to a wide variety of disorders and many of them lead to causes of death [74] which have been summarized below.

6.1. Antioxidant Activities of P. ginseng in Sensor Impairment

6.1.1. Ototoxicity

Age-related hearing loss is considered to be an ROS-mediated disorder. Other causes of hearing loss are noise, antibiotics (Aminoglycoside, cisplatin) consumption, and immune-mediated hearing loss [75]. Many studies have exhibited that ginseng is helpful to prevent ototoxicity caused by different sources. Aminoglycosides including gentamicin react with iron in the inner ear and produce ROS with damage to hair cells and neurons. Choung et al. showed that ginsenoside Rb1 and Rb2 are effective against aminoglycoside-induced hearing loss by attenuating ROS generation and IL-6 inhibition [76]. The organ of Corti reaches its maximum intensities of ROS and RNS generation after seven to ten days of noise insult [77]. Additionally, ginsenoside Ck and Rg2 have therapeutic effects against noise-induced hearing loss in mice by reducing the levels of ROS and RNS [78]. Ginseng extract protects against cisplatin-induced ototoxicity of the auditory cell line (HEI-OC1) due to its anti-apoptotic and anti-oxidative stress effects [79].

6.1.2. Ocular Disease

It is believed that oxidative stress is involved in many age-related eye illnesses including retinal degeneration and cataract, glaucoma, and diabetes retinopathy, etc.; cataract is an age-related loss of transparency of the eye lens because of the formation of protein complexes in the lens [80,81,82]. ROS and ultraviolet radiations damage crystalline proteins during aging, resulting in the insoluble protein clumps of the lens being opaque which interferes with vision. Park et al. recognized that ginsenoside CK blocked ROS production via Nrf2/HO-1 activation in the H₂O₂-stimulated ARPE-19 cell line to prevent cataracts [82]. After cataracts, glaucoma is the second leading reason for blindness which is associated with intra-ocular pressure and a loss of vision [83]. An overproduction of ROS leads to apoptosis in retinal ganglion cells that cause glaucoma [84]. Several studies showed evidence that ginseng supplements and ginsenosides are very useful against glaucoma. Ginsenoside Rb1 protects retinal ganglion cells against apoptosis caused by H₂O₂-induced oxidative stress [85]. Moreover, patients with glaucoma who consumed 3 g of Korean red ginseng daily for 4 weeks observed an improvement in their daytime visual acuity and ocular pain [86]. Eight weeks of consumption of KRG reduces the symptoms of dry eye in glaucoma patients by improving the tear film stability [87].

6.2. Antioxidant Activities of P. ginseng in Neurogenerative Diseases

The central nervous system (CNS) is extremely vulnerable to oxidative injury due to its utilization of a high pace of oxygen [88]. An overproduction of ROS and inadequate antioxidant defense systems have been connected to the pathophysiology of numerous neurogenerative disorders such as Huntington’s disease (HD), Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS), and Alzheimer’s disease (AD) [89]. Neuroprotection inhibits or delays the neurogenerative process to minimize neuronal death [90]. In this case, secondary metabolites of plants which are rich in antioxidant content can protect the nerve cells from free-radical-induced oxidative stress to prevent neurogenerative diseases [91]. The research into and recognition of the potential impact of Panax ginseng on ROS-mediated neurogenerative diseases are growing day by day.

6.2.1. Parkinson’s Disease

Parkinson’s disease (PD) is a chronic neurodegenerative condition that affects approximately 2% of people over 60 years old worldwide. PD depends on the interplay between various genetic and environmental factors and is marked by the development and accumulation of misfolded-α-synuclein [90]. The hallmark symptoms of PD include motor disorders (rigidity, tremor, and bradykinesia) and non-motor disorders (depression, sleep disturbance, and autonomic dysfunction) resulting from the gradual deterioration of the dopaminergic pathway [92]. Several studies have depicted that ginseng and its bioactive components, ginsenosides, have therapeutic actions on PD. P. ginseng extracts can inhibit ROS generation, eliminate Bax/Bcl2, increase the cytochrome C release, and stimulate caspase-3 expression to alleviate cell death [93]. Ginsenoside Rg1 suppressed the oxidative stress to mediate the neuroprotective action in MPTP (1-methyl-4-phenyl-1,2,3,6-twtrahydropyridine)-induced substantia nigra [94,95]. Rg1 activates total superoxide dismutase (SOD) and inhibits glutathione reduction, reducing c-Jun and N-terminal kinase (JNK) in the substantia nigra of C57BL/6 mice [94]. Furthermore, Rg1 decreases ROS production and mitochondrial cytochrome C and blocks the activation of caspase 3 and the formulation of the iNOS protein and NO in PC12 cells [96]. Again, Rg1 attenuates ROS generation and NF-ĸB translocation in MPP+-induced MES23.5 cells for reducing the expression of DMT1-IRE [97]. Ginsenoside Re shows neuroprotective action against the neurotoxicity of substantia nigra. Ginsenoside Re increases the Bcl-2 mRNA and Bcl-2 protein expression decreases the iNOS, Bax, and Bax mRNA and inhibits the cleavage of caspase-3 to protect the SN neuron from MPTP-induced apoptosis [98].

6.2.2. Alzheimer’s Disease

Alzheimer’s disease (AD) is a cognitive condition defined by the accumulation of senile plaques, the development of neurofibrillary tangle, and finally the death of neurons. The improper degradation of the amyloid precursor protein (APP) is the primary mechanism causing AD progression [99,100]. Several changes in molecular and cellular pathways including mitochondrial dysfunction, antioxidant decreases, oxidative stress increases, synaptic impairment, and amyloid Aβ clearance capacity are present in the AD brain [101,102,103]. Many studies have distinguished that P. ginseng extract, powder, and ginsenosides were applied to AD in in vivo and in vitro studies. The total saponins of ginseng consumption for seven months revealed a remarkable reduction in memory loss by inhibiting oxidative stress and increasing the proteins associated with plasticity in aged mice [104]. Ginsenoside Rb1 shields neurons from Aβ1-42 neurotoxicity via an antioxidant mechanism [105]. Rb1 pre-treatment in PC12 cells for 1 day inhibits the overproduction of ROS and lipid peroxidation enhances the activation of caspase-3 and Bcl-2/bax for promoting cell survival [106]. In H₂O₂-induced PC12 cells, Rg1 prevents NF-κB/P65, ERK1/2, and Akt stimulation [107]. Rg1 can protect PC12 cells from cytotoxicity caused by Aβ25-35 by preventing β-secretase activities [108]. However, the ref. [109] experiment found for the first time that ginsenoside Rk3 can trigger the intracellular ROS level and Aβ-induced neuronal injury by stimulating the AMPK pathway and the upregulation of Nrf2. Interestingly, this study also confirmed that the pharmacological activity of ginsenoside Rk3 is better than the control drug donepezil in case of the treatment of AD. Recently, a new ginseng component gintonin has been discovered that is effective in reducing the severity of AD-related neuropathies [110].

6.2.3. Others

P. ginseng and its active components are also effective in Huntington’s disease (HD), amyotrophic lateral sclerosis (ALS), depression, neuroprotection, and improvement in cognition [111]. Wang et al. recognized that ginseng sesquiterpenoids down-regulate the NF-κB and BDNF/TrkB signaling pathways, and increase SOD production in the hippocampus of the ICR mice model. The result exhibited that the SP of ginseng shows antidepressant activity via Sirt1/NF-κB and BDNF/TrkB pathways [112]. Water extract of Korean red ginseng acts as a neuroprotector through the regulation of the Nrf2 signaling pathway [113]. Ginsenoside Rb1 exhibits strong antioxidant activity in the treatment of many neurological diseases including strokes [114]. Ginsenosides Rg3 and Rg1 are useful in cognition improvement via regulating the NF-κB and PI3K/Akt signaling pathways in mice models [115,116]. It has been reported that P. ginseng fibrous root (GFR) shows good antioxidant activity to scavenge free radicals. GFR enhanced the expression of antioxidant enzymes to trigger the intracellular ROS which ultimately accelerated Alzheimer’s and other neurogenerative diseases [117].

6.3. Antioxidant Activities of P. ginseng in Cardiovascular Diseases

Cardiovascular disease (CVD) is a critical challenge among 50% of the world’s population [118]. CVD includes hypertension, coronary artery disease, massive heart failure, and peripheral vascular disease, etc., which are common and affect newborns, children, and adults of both sexes [119]. Research shows that the enhancement of reactive oxygen species and oxygen consumption is one of the crucial factors in CVD outbreak. For example, heart failure can be caused by ROS-inducing cardiac apoptosis and necrosis [120,121], as well as increased oxidant generation via the NADH/NADPH oxidant, and superoxide-generated endothelium breakdown results in hypertension and coronary artery disease [122,123]; furthermore, an overproduction of ROS and oxidant-mediated myocyte apoptosis and necrosis causes myocardial infarction [124,125]. An excessive amount of free oxygen from heart ischemia causes myocardial damage; however, ginseng consumption increases blood flow by inhibiting free oxygen and myocardial damage [126]. Ginsenoside Rb1 can inhibit the production of ROS to reduce homocysteine which causes endothelial dysfunction [127]. Ginsenoside Re protects the myocardial cell from oxidative damage and increases myocardial cell viability in heart ischemia [128]. Total ginsenosides enhance coronary artery perfusion flow by activating the PI3K/Akt-eNOS signaling pathway that ultimately produces NO levels [129]. Ginsenoside-Rb1 administration increases eNOS expression which also increases NO levels and decreases super oxides in the porcine coronary artery via the vasodilating mechanism [127]. In addition, the saponin fractions of Korean red ginseng decrease blood pressure and prompt reflex tachycardia due to their hypotensive effect and the mechanism of NO donation [130]. In another study, total ginsenosides were effective against right ventricular hypertrophy, promoted systolic pressure, and reduced pulmonary pressure by controlling the ERK-1/MAPK signaling pathway [131]. Hong et al. demonstrated that the consumption of PPT-rich ginseng enhances the activation of eNOS, stimulates NO formulation, and improves the thickness of the vessel walls to attenuate hypertension [132]. Previous studies have depicted that ginsenoside Rg1 inhibited Bcl-2 and caspase-3 expression during myocardial infarction via ischemia to lower myocardial cell death and decreased left ventricular hypertrophy [133]. In another study, ginsenoside CK reduced the burden of myocardial infraction by increasing the protein kinase B(Akt) and nitrogen oxide synthetase (eNOS) followed by ischemia via the Akt/PI3K pathway [134]. Although it has also been reported that ginsenoside Rg3 mitigates myocardial ischemia-reperfusion injury (MIRI) via the AKT/eNOS and Bcl-2/Bax signaling pathways [135], ginsenoside Rd reduces MIRI via the Nrf-2/HO-1 pathway [136], and ginsenoside Rb1 inhibits cardiomyocyte autophagy via the PI3K/Akt/mTOR pathway, thus controlling MIRI [137]. Recently, ref. [138] confirmed that ginsenoside Rh2 provides anti-inflammatory and antioxidant activity on MIRI via the regulation of the Nrf2/HO-1/NLRP3 signaling pathway.

6.4. Antioxidant Activities of P. ginseng in Cancer

According to growing data, ROS are implicated in multiple steps of tumorigenesis from the initiation of the tumor to metastasis [139]. Excessive amounts of ROS in the cell or the defective antioxidant defense mechanisms quicken the cellular damage and initiate carcinogenesis [140]. It has been reported that the cancer cell initiates more ROS than their counterpart [141]. ROS play a dual role in cancer. First, the overabundance of ROS instigates autophagy, apoptosis, and cell cycle arrest signals [142,143]. Second, ROS can influence the initiation, growth, and transmission of cancer via the activation of the signaling pathways which affect cell proliferation, survivability, angiogenesis, and metastasis [139]. In general, when ROS are low to moderate, they may contribute to the initiation of a tumor, and a high amount of ROS causes massive cell damage and death, typically at the early stages of tumor formation [144]. So, it may be possible to destroy cancer cells specifically by raising oxidative stress through exogenous ROS production without significantly harming normal cells [145].

P. ginseng and its derivatives, ginsenosides, might be a promising supplemental therapy for cancer patients. According to growing researches, ginsenosides have a lot of potential to offer multiple strategies for treating different cancers (

Table 2. ROS-associated effects of ginseng and ginsenosides on cancer cells.

Cancer Cell	Ginseng/Ginsenosides	Mechanisms	Effect	References
Leukemia Jurkat cells	Rh2 and Rg3	ROS↑, MTP↓, caspase-3/9↑, Bax/Bcl-2↑, Cyt C↑	Stimulated mitochondrial ROS that inhibited cell proliferation and induced apoptosis.	[149]
Acute Lymphoblastic leukemia cells	20(S)-Ginsenoside Rh2	ROS↑, MTP↓, Cyt C↑, caspase-3/9↑, LC3-I↑, LC3-II↑, Atg5↓, Beclin-1↑	Generated mitochondrial ROS that inhibited autophagy and induced apoptosis.	[150]
Lung cancer NCI-H460 cell	Compound K	ROS↑, MMP↓, caspase-3↑	Increased γ-ray-induced apoptosis by enhancing intracellular ROS production that reduced MMP and increased caspase-3.	[151]
Colorectal cancer HCT-116	Rh2	ROS↓, Bax/Bcl-2↑, capase-3↑, G1↓, S ↓	Reduced the formation of ROS which activated autophagy and antiproliferative effects.	[152]
Colorectal cancer	Protopanaxadiol	ROS↑, NF-κB↑	ROS production activated the NF-ĸB pathway that induced paraptosis.	[153]
Colon cancer HCT-116 cells	Compound K	ROS↑, Mcl-1↓, Bcl-2↓, survivin↓, XIAP↓, cFLIP↓, Bax↑, tBid↑, Cyt C↑, LC3-II↑, Atg7↑, JNK↑, ERK↓, p38↓, p53↑, DR5↑, CHOP↑	Stimulated TRAIL-induced apoptosis by upregulating DR5 in both autophagy in a dependent and dependent manner.	[154]
Hepatoma HepG2 cells	Rh2	Caspase-3/9↑, cytosol Cat B↓, leupeptin (Leu) ↑, MTP↓, Bid↑, tBid↑, Cyt C↓	Mitochondrial apoptotic and ROS-accumulation- pathway-induced apoptosis.	[155]
Hepatoma HepG2 cells	Rh2	PARP↑, ROS↑, p-p38↑, p-AMPK↑	Activation of AMPK-mediated ROS generation that induced apoptosis.	[156]
Hepatoma Hep3B cells	Rg3 and Rh2	ROS↑, caspase-3↑, Bcl-2↓, Bax↑, Cyt C↑, MTP↓	Mitochondria-mediated apoptosis pathway and ROS generation caused apoptosis.	[157]
Breast cancer MCF-7 cells	Compound K	MTP↓, AMPK↑, COX-2↓, PGE2↓	Modulation of the AMPK signaling pathway and ROS production induced apoptosis.	[158]
Breast cancer MDA-MB-231 cells	Rg3	ROS↑, Bax/Bcl-2↓, MTP↓, caspase-3↑, PARP↑	Apoptosis was caused by the activation of the mitochondrial death pathway.	[159]
Breast cancer MCF-7 cells	BG-AuNps and BG-AgNps	ROS↑	ROS production caused oxidative cell damage and apoptosis.	[160]
Cervical carcinoma HeLa cells	Rh2	ROS↑, MTP↓, Caspase-3↓, JNK1↑, SEK1↑, JNK2↑, c-Jun↑, Smac↑, Bax↑, Ca2+↑	Initiated apoptosis by generating ROS and Ca2+ which activated SEK1 and JNK1.	[161]
Bladder cancer T24 cells	Compound K	Cyt C↑, Bax↑, Bcl- 2↓, p-p38MAPK↑, procaspase-3/9↑, p38↑, ROS↑, glutathione↓	Induced apoptosis through ROS-mediated P38 MAPK pathway.	[162]
Gastric carcinoma SGC7901 cells	F2	PARP↓, ASK-1↑, JNK↑, Bcl-2↓, Cyt C↑, Caspase-3/9↑	Induced apoptosis via modulating the ASK-1/JNK signaling cascade and ROS– mitochondria pathway.	[10]
Esophageal cancer cells	Ro	ROS↑, CYBB/Nox2↑, LC3B-II↑, ATG7↑, ESR2↓, NCF1↑, SQSTM1/p62↑, CSTB↓ CSTD↓, p-CHEK1↑, EGFR↑, DDIT3↑, ATM↑, ATR↑, BRCA1↑, GFP-LC3B puncta↑, Lysosomal pH↑, autophagic vacuoles↑	ERSR2-NCF1-ROS signaling pathway suppressed autophagy and decreased CHEK1 degradation which sensitized 5-fluorouracil inducing cell death.	[163]
Neuroblastoma SH-SY5Y cell	Rg1	ROS↓, JNK↑, caspase-3↑	Inhibited the generation of ROS and activated the JNK pathway to inhibit MPP+-induced apoptosis.	[164]
Astrocytoma CRT-MG cells	Compound K, ginsenoside Rh2	ROS↑, caspase-3↑, Cyt C↑, p-p38↑, Fas↑, MIP↓	Increased Fas-dependent apoptosis in ROS/caspase/ mitochondrial pathways.	[165]
Neuroblastoma SH-SY5Y cell	Ginseng water extract	ROS↑, Bcl-2↓, Bax↑, Cyt C↑, caspase-3↑	Alleviated oxidative stress in the mitochondrial apoptotic pathway to prevent MPP+-induced apoptosis.	[166]
GliomaU87 cells	20(S)-ginsenoside Rg3	ROS↑, p21↑, p16↑, p53↑, Akt↑	Enhanced ROS generation via Akt- and p53/p21-dependent pathways that induced senescence-like growth arrest.	[167]
Glioblastoma U87MG cells	Rg3	Bcl-2↓, Bax↑, pro-caspase3↓, MEK1/2↑, ROS↑	Induced apoptosis via ROS and MEK pathway.	[168]
Lung cancer A549 cells	Rh1	↑P53, ↑Bax, ↑caspase 3, ↑caspase 9, ↓Bcl	Intrinsic pathway.	[147]
Colorectal carcinoma SW-480 and HCT-116	Rh2	Bax↑, Bad ↑, ROS ↑, NF-ĸB↑, Bad↓, Bcl-xL↓, P53↓, Cytosolic vacuolization↓	ROS/NF-ĸB signaling pathway/P53 and NF-ĸB signaling pathway. (Upregulation of ROS induced apoptosis by activating NF-ĸB and P53.)	[169]
Hepatoma HepG2 cells	Korean white ginseng extract	Cyt C↑, c-Jun↑, SAPK↑, MDA↓, Caspase-3↑, Iĸ-b↓,	Apoptosis induction through JNK/NF- ĸB/Cyt C apoptotic pathway and antioxidant activities.	[170]
Breast cancer MDA-MB-231 cells	Rg3	NF-ĸB↓, Bcl-2↓, Akt ↓, IĸB↓, p-ERK↓	NF-ĸB inhibition via Akt and ERK inactivation.	[171]
Lung cancer A549, H1299, and H358 cells	Rg3	EMT↓, EGFR ↓, MAPK↓, NF-κB↓	MAPK and NF-κB blocking to induce apoptosis.	[172]

Notes: ↑ = upregulation, ↓ = down regulation, abbreviations: ROS = reactive oxygen species, MTP-microsomal triglyceride transfer protein, Bax-Bcl-associated-2 protein, Cyt C-cytochrome C, LC-3I-light chain-3I, Atg-5-autophagy-related 5, MMP-matrix metalloproteinase, NF-κB-nuclear factor kappa B, XIAP-X linked inhibitor of apoptosis protein, cFLIP-cellular FLICE-like inhibitory protein, tBid-truncated Bid, JNK$-c-Jun N-terminal kinase, ERK-extracellular signal-regulated kinase, CHOP-C/EBP homogenous protein, PARP-Poly (ADP ribose) polymerase-1, AMPK-AMP-activated protein kinase, Cox-2-Cyclooxygenase-2, PGE-2-Prostaglandin E2, Smac-second mitochondria-derived activator of caspase, MAPK-mitogen-activated protein kinase, ASK-1-apoptosis signal-regulating kinase, NCF-1-neutrophil cytosolic factor-1, CSTB-Cystatin B, CSTB-Cystatin D, EGFR-epidermal growth factor receptor, DDIT3-DNA damage-inducible transcript 3 protein, ATM-Ataxia-telangiectasia-mutated, ATR-Ataxia-telangiectasia and Rad-3 related, BRCA-1-breast cancer gene-1, EMT-epithelial mesenchymal transition, and EGFR-epidermal growth factor receptor.

). Therefore, it might be difficult for cancer cells to develop resistance against ginsenosides. Additionally, ginsenosides are desirable candidates for new therapeutics due to their ability to destroy tumor cells. In general, ginsenosides can produce ROS in a variety of cancer cells which can enhance autophagy, apoptosis, paraptosis, and decrease cell proliferation in vivo and in vitro [139]. However, according to current research, by comparing between healthy and cancer cell lines (CCD841 and HT-29), ref. [146] confirmed that P. ginseng berry extract exhibited prebiotic activity against colorectal cancer by increasing ROS production without affecting the normal cells. It has also been newly proposed that ginsenoside Rh1 from P. ginseng is a potential compound to prevent and treat lung cancer through the regulation of metastasis and apoptosis [147]. P. ginseng extract suppresses ROS production by increasing the antioxidant biomarker GSH, and reduces the inflammatory biomarker TNF-α and apoptotic biomarker caspase-3 to prevent doxorubicin-induced cardiovascular disease [148].

6.5. Antioxidant Activities of P. ginseng in Other Diseases

ROS play a crucial role in the development of diabetes, kidney diseases, aging, etc. [173]. Mitochondrial DNA damaged by ROS is the primary cause of aging. Oxidative damage causes mitochondrial dysfunction and the translation and multiplication of mitochondrial DNA that promotes ROS production which damages mtDNA [174]. However, ginsenoside Rd consumption for one month quickens the cellular senescence to increase the antioxidant enzyme GPx and GR in mitochondria [175]. Moreover, ginsenoside Rb2 increases SOD, CAT activities, and also blood albumin which reduces oxidative stress from the skin cell [176]. According to Ramesh et al., Korean red ginseng reduces MDA levels, creatinine, AST, ALT, and urine nitrogen at higher levels Furthermore, KRG induces SOD, GPx, GST, GR, and CAT activity in the lungs and heart [70]. Additionally, P. ginseng derivative syringaresinol (SYR) shows antioxidant activity and stimulated autophagy in H₂O₂-induced Hacat cells, therefore inhibiting the mRNA expression of MMP-2 and MMP-9 related to skin aging [177]. SYR may have therapeutic potential to treat diabetic cardiomyopathy by reducing oxidative stress, fibrosis, and inflammation [178].

Furthermore, Korean red ginseng prevented the blood glucose levels in STZ-induced diabetic rats [179]. In addition, it was recognized that ginsenoside Rd consumption via acute renal failure in rats increases SOD and catalase in renal tissue and serum [180]. Recent studies have shown that ginseng triggers pro-inflammatory cytokine (IL-6, IL-1β, and TNF-α) expression as well as activates ROS-mediated pathways to show antifatigue activity through anti-oxidation and anti-inflammatory activity [181]. Research has shown that P. ginseng plays as anti-inflammatory, immunostimulatory, neuroprotective, hepatoprotective, antiplatelet, antidiabetic, and anti-angiogenesis roles. Korean ginseng and its ginsenosides are effective in various anti-inflammatory diseases including colitis, gastritis, and hepatitis. Han et al. depicted that ginseng shows anti-inflammatory activity by preventing Akt [182]. Moreover, Rg1 could be a useful approach for preventing acute liver damage by stimulating the Nrf2 signaling pathway [183]. Additionally, ginseng can regulate streptozotocin-induced diabetes by increasing antioxidant enzymes [69]. Moreover, ref. [184] depicted that fermented black ginseng (P. ginseng) can reduce ROS levels in H₂O₂-induced Hacat cells via its antioxidant activity compared to black and white ginseng. Furthermore, FBG shows higher anti-wrinkle and anti-melanogenic activity than BG and WG [185].

7. Nano-Formulation Forms of Phenolic Compounds as a Solid Alternative in Current Treatment Methods

P. ginseng consists of approximately 80–90% organic and about 10–20% inorganic compounds. It has already been shown that the active ingredients of P. ginseng comprise a vast number of beneficial activities [186]. Several studies have discussed the pharmacological activities of P ginseng such as antioxidant, anti-inflammatory, anticancer, neuroprotective, cardioprotective, antidiabetic, anti-allergic, anti-stress, hypolipidemic, antifatigue, anti-depressive, antitumor, anti-adhesive, anti-aging, etc., which express the potentials of ginseng as a complementary and alternative medicine (CAM) [187,188]. Additionally, Acero et al. [189] demonstrated that P. ginseng is an ayurvedic medicine (AM), traditional medicine (TM), and also a traditional Chinese medicine (TCM). P. ginseng is most frequently employed in therapeutic applications due to its significant pharmacological activities [190]. Moreover, ginsenosides Rg, Re, and Rb are still exploited in Chinese pharmacopeia as molecular markers for quality assessment [191]. Along with ginsenosides, some essential phenolic compounds from P. ginseng have been reported such as syringic, ferulic, cinnamic, gentistic, and p-hydrobenzoic acid [188]. Researchers from a variety of disciplines have been interested in these active compounds [192]. However, these natural by-products have limited therapeutic efficacy due to high hydrophobicity, poor bioavailability, low in vivo stability, and short half-life. In fact, modification and conjugation (nano-formulation) have been hastening the study and the therapeutic use of these components [193]. A significant step forward in the effort to boost therapeutic efficacy by lowering toxicity, raising bioavailability, enhancing stability, and optimizing pharmacokinetics is the use of natural ingredients in nano-formulations [194]. In recent years, a wide range of nanomaterial-based delivery systems have been subjected to ginsenosides, curcumin, quercetin, resveratrol, ferulic acid, gamboxylic acid, and other polyphenols. These nano-formulations exhibit improved solubility, slower release, more precise targeting, greater bioavailability, and suitability for conventional drug administration methods including injections and oral capsules in comparison to free forms (

Table 3. Nano-formulations of active components.

Compounds	Nano-Formulations	Benefits	References
Ginsenoside Rg3	Mixed micelles containing baicalin copolymer P123. G-Rg3 conjugated with nanoparticle. G-Rg3 with CNC nanocomposite. Liposomes of G-Rg3	Increases drug absorption in cancer cells and boosts baicalin solubility. Inhibits the growth of hepatocellular carcinoma (HCC) and prevents lung metastasis. Enhances antioxidant activity. Antitumor activity is greater than free formulation. Increases uptake, sustains release, bioavailability, and enhances cytotoxicity in cancer cells.	[194,197,198]
Ginsenoside Rg5	Liposomes of G-Rg5	Inhibits tumor growth, tumor targeting.	[199]
Ginsenoside Rh2	Micelles	Enhances water solubility and drug uptake. Elongates drug retention.
	Mesoporous silicas	Excellent biocompatibility to normal cell (Hacat cell).
Curcumin	PLA polymer, chitosan, gum arabic	Enhances cellular uptake, and antioxidant and anticancer activities.	[200,201]
		Increases antioxidant activity.	[202]
Quercetin	PLA	Induces self-life.	[203]
	Chitosan-CMC	Enhances stability, solubility, and antioxidant activity.	[204]
	Chitosan-pluronic F-127-STPP	Wound healing.	[205]
Resveratrol	PLGA-PEG	Improves nonvascular effects.	[206]
	Lecithin/chitosan	Promotes anti-inflammatory effects.	[207]
Ferulic acid	Ferulic acid polymer nanoparticles	Reduces ROS activity.	[208]
	Nanoparticles of poly ferulic acid	Improved colon cancer treatment.	[208]

Abbreviation: PLA-poly lactic acid, PGMD-poly-glycerol-malic acid–dodecanedioic acid, CMC-carboxymethyl chitosan, PEG-polyethylene glycol.

) [195]. Furthermore, nanocarriers also reduce the side effects of drugs as it only takes small doses for them to have biological impact [196].

8. Discussion

Mitochondria are collectively known as the power houses of eukaryotic cells. The major roles of mitochondria are cell metabolism and regulating pathways related to energy generation. Furthermore, mitochondria are the main source of ROS which play a significant role in the cellular redox biology and are influenced by their generation and accumulation [207,209]. ROS are highly reactive due to their unpaired electron that can interact with several macromolecules in the cell such as proteins, nucleic acids, carbohydrates, and lipids, and change their molecular functions. This redox state control is essential for maintaining the functions of the organ, cell viability, cell activity, and cell proliferation. An oversupply of ROS from various sources (both internal and external) has been shown cellular biomolecular damages and mitochondrial dysfunction and trigger mitochondrial biogenesis, which is the main reason for several chronic diseases such as neurogenerative, cardiovascular, metabolic diseases, cancer, etc.

However, antioxidants act as an essential role in the scavenging and inducing of free radicals. Natural antioxidants, for example, polyphenols, flavonoids, acid polysaccharides, amino acids, phytosterol, and carbohydrates, found in food and plants have remarkable efficacy to protect the healthcare system from oxidative stress [208]. These compounds diminish ROS production and increase mitochondrial biogenesis as well as improve the function of mitochondria [207]. Among the thousands of antioxidant-rich sources, P. ginseng is the most lexical source of antioxidants that is traditionally used to prevent and treat diseases, which has been discussed in this review in Section 6. P. ginseng increases the activity of antioxidant enzymes such as SOD, CAT, GPx, GST, and the Nr-f2-related enzyme Ho-1 that inhibits ROS production to protect cells from apoptosis, autophagy, and tumor progression. However, they promote the generation of ROS to kill the cancer cell. As shown above, P. ginseng and ginsenosides regulate ROS in ROS-mediated disease states. Among all of the secondary metabolites of ginseng, the ginsenosides Rh2, Rg1, Rg3, Ro, F2, and compound K have the higher efficacy to kill cancer cells by regulating ROS generation.

Despite the fact that P. ginseng has a reputation for being safe, several studies have raised concerns regarding the side effects of ginseng such as allergies and toxicity to the lung, heart, liver, kidney, and reproductive organs [209]. As a result, the use of ginseng in humans need to go through a standard consuming system as well as a number of additional controlled conditions including optimum regular dose durations and precise assessment of the patient’s overall health. Several studies have shown that to minimize the side effects from plant extracts and their components, nanotechnology has become an essential tool. By developing a nanocarrier system, the stability and solubility of these compounds has been shown to be improved [196].

9. Conclusion and Future Perspectives

In this study, we discussed that P. ginseng and its constituents have physiological processes that reduce the symptoms of certain diseases through the antioxidant mechanisms in cells and animals. P. ginseng is well-known for its antioxidant activities that alleviate several chronic diseases such as sensor impairment, cardiovascular diseases, neurogenerative disease, cancer, aging, and metabolic diseases. Although P. ginseng has been proven to increase antioxidant activity in humans as measured by several oxidative stress indications, the limitations of P. ginseng are not deniable. Furthermore, it will be essential to establish the precise efficacy, cytotoxicity, and systemic mechanisms for these chronic diseases via antioxidant action in clinical trials in the future.