Research

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12 pages, 3409 KiB

Open AccessArticle

Anti-Inflammatory Flavonoids from Agrimonia pilosa Ledeb: Focusing on Activity-Guided Isolation

by Mijin Park, Dahye Ryu, Jwayeong Cho, Kang-Mo Ku and Young-Hwa Kang

Molecules 2024, 29(2), 283; https://doi.org/10.3390/molecules29020283 - 05 Jan 2024

Viewed by 755

To elucidate the anti-inflammatory properties and constituents of Agrimonia pilosa Ledeb. (A. pilosa), a comprehensive investigation was conducted employing activity-guided isolation. The anti-inflammatory effects were evaluated through an in vitro nitric oxide (NO) assay on lipopolysaccharide (LPS)-treated RAW 264.7 macrophage cells. [...] Read more.

To elucidate the anti-inflammatory properties and constituents of Agrimonia pilosa Ledeb. (A. pilosa), a comprehensive investigation was conducted employing activity-guided isolation. The anti-inflammatory effects were evaluated through an in vitro nitric oxide (NO) assay on lipopolysaccharide (LPS)-treated RAW 264.7 macrophage cells. Seven bio-active compounds with anti-inflammatory properties were successfully isolated from the butanol fraction and identified as follows: quercetin-7-O-β-d-rhamnoside (1), apigenin-7-O-β-d-glucopyranoside (2), kaempferol-7-O-β-d-glucopyranoside (3), quercetin (4), kaempferol (5), apigenin (6), and apigenin-7-O-β-d-glucuronide-6″-butylester (7). All isolated compounds showed strong NO inhibitory activity with IC₅₀ values ranging from 1.4 to 31 µM. Compound 6 demonstrated the most potent NO inhibition. Compound 7, a rare flavonoid, was discerned as a novel anti-inflammatory agent, ascertained through its inaugural demonstration of nitric oxide inhibition. Subsequently, a comprehensive structure-activity relationship (SAR) analysis was conducted employing eight flavonoids derived from A. pilosa. The outcomes elucidated that flavones exhibit superior NO inhibitory effects compared to flavonols, and the aglycone form manifests greater potency in NO inhibition than the glycone counterpart. These results highlight A. pilosa as a promising source of effective anti-inflammatory agents and indicate its potential as a health-beneficial dietary supplement and therapeutic material. Full article

(This article belongs to the Special Issue Anti-inflammatory Activities of Natural Compounds)

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19 pages, 4723 KiB

Open AccessArticle

Tiliroside Attenuates NLRP3 Inflammasome Activation in Macrophages and Protects against Acute Lung Injury in Mice

by Chao Zhong, Jing Yang, Keke Deng, Xiaoya Lang, Jiangtao Zhang, Min Li, Liang Qiu, Guoyue Zhong and Jun Yu

Molecules 2023, 28(22), 7527; https://doi.org/10.3390/molecules28227527 - 10 Nov 2023

Viewed by 894

Abstract

The Nod-like receptor family PYRIN domain containing 3 (NLRP3) inflammasome is a multiprotein signaling complex that plays a pivotal role in innate immunity, and the dysregulated NLRP3 inflammasome activation is implicated in various diseases. Tiliroside is a natural flavonoid in multiple medicinal and [...] Read more.

The Nod-like receptor family PYRIN domain containing 3 (NLRP3) inflammasome is a multiprotein signaling complex that plays a pivotal role in innate immunity, and the dysregulated NLRP3 inflammasome activation is implicated in various diseases. Tiliroside is a natural flavonoid in multiple medicinal and dietary plants with known anti-inflammatory activities. However, its role in regulating NLRP3 inflammasome activation and NLRP3-related disease has not been evaluated. Herein, it was demonstrated that tiliroside is inhibitory in activating the NLRP3 inflammasome in macrophages. Mechanistically, tiliroside promotes AMP-activated protein kinase (AMPK) activation, thereby leading to ameliorated mitochondrial damage as evidenced by the reduction of mitochondrial reactive oxygen species (ROS) production and the improvement of mitochondrial membrane potential, which is accompanied by attenuated NLRP3 inflammasome activation in macrophages. Notably, tiliroside potently attenuated lipopolysaccharide (LPS)-induced acute lung injury in mice, which has been known to be NLRP3 inflammasome dependent. For the first time, this study identified that tiliroside is an NLRP3 inflammasome inhibitor and may represent a potential therapeutic agent for managing NLRP3-mediated inflammatory disease. Full article

(This article belongs to the Special Issue Anti-inflammatory Activities of Natural Compounds)

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15 pages, 3005 KiB

Open AccessArticle

Atractylone in the Atractylodes macrocephala Rhizoma Essential Oil and Its Anti-Inflammatory Activity

by Ling Li, Yihao He, Nan Wang, Yuting Li, Yaoyao Du, Ning He, Bing Wang and Tong Zhang

Molecules 2023, 28(21), 7340; https://doi.org/10.3390/molecules28217340 - 30 Oct 2023

Cited by 1 | Viewed by 1071

Abstract

The aim of this study was to conduct a screening of potential therapeutic compounds found in the Atractylodes macrocephala rhizoma essential oil (AO) and explore its mechanism of action in the treatment of ulcerative colitis (UC). An inflammation cell model was employed in [...] Read more.

The aim of this study was to conduct a screening of potential therapeutic compounds found in the Atractylodes macrocephala rhizoma essential oil (AO) and explore its mechanism of action in the treatment of ulcerative colitis (UC). An inflammation cell model was employed in conjunction with phospho-antibody array technology to explore potential therapeutic compounds of AO and their anti-inflammatory and antioxidant effects. Furthermore, we assessed their efficacy and mechanisms of action in treating dextran sulfate sodium (DSS)-induced colitis in mice. Via the screening process, we identified atractylone (ATR) as the primary active compound in AO. It has been demonstrated that ATR can both decrease the levels of tumor necrosis factor (TNF)-α and reactive oxygen species (ROS) and increase the expression of adhesion proteins such as claudin, ZO-1, and occludin in vitro. Moreover, ATR has been shown to improve UC symptoms in vivo. Via a non-targeted metabolomics analysis of colon tissue, we identified 57 distinct metabolites that responded to ATR treatment. Subsequent analysis of the metabolic pathways revealed that the action of ATR was primarily focused on the amino acid metabolism pathway. In summary, ATR may alleviate the symptoms of UC by regulating multiple signaling pathways. Additionally, ATR has a comprehensive function in anti-inflammation, antioxidative stress, and intestinal injury reduction. Full article

(This article belongs to the Special Issue Anti-inflammatory Activities of Natural Compounds)

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16 pages, 3236 KiB

Open AccessArticle

Cis-Nerolidol Inhibits MAP Kinase and NF-κB Signaling Pathways and Prevents Epithelial Tight Junction Dysfunction in Colon Inflammation: In Vivo and In Vitro Studies

by Vishnu Raj, Balaji Venkataraman, Shreesh K. Ojha, Saeeda Almarzooqi, Veedamali S. Subramanian, Basel K. Al-Ramadi, Thomas E. Adrian and Sandeep B. Subramanya

Molecules 2023, 28(7), 2982; https://doi.org/10.3390/molecules28072982 - 27 Mar 2023

Cited by 4 | Viewed by 1564

Abstract

Inflammation of the GI tract leads to compromised epithelial barrier integrity, which increases intestine permeability. A compromised intestinal barrier is a critical event that leads to microbe entry and promotes inflammatory responses. Inflammatory bowel diseases that comprise Crohn’s disease (CD) and ulcerative colitis [...] Read more.

Inflammation of the GI tract leads to compromised epithelial barrier integrity, which increases intestine permeability. A compromised intestinal barrier is a critical event that leads to microbe entry and promotes inflammatory responses. Inflammatory bowel diseases that comprise Crohn’s disease (CD) and ulcerative colitis (UC) show an increase in intestinal permeability. Nerolidol (NED), a naturally occurring sesquiterpene alcohol, has potent anti-inflammatory properties in preclinical models of colon inflammation. In this study, we investigated the effect of NED on MAPKs, NF-κB signaling pathways, and intestine epithelial tight junction physiology using in vivo and in vitro models. The effect of NED on proinflammatory cytokine release and MAPK and NF-κB signaling pathways were evaluated using lipopolysaccharides (LPS)-stimulated RAW 264.7 macrophages. Subsequently, the role of NED on MAPKs, NF-κB signaling, and the intestine tight junction integrity were assessed using DSS-induced colitis and LPS-stimulated Caco-2 cell culture models. Our result indicates that NED pre-treatment significantly inhibited proinflammatory cytokine release, expression of proteins involved in MAP kinase, and NF-κB signaling pathways in LPS-stimulated RAW macrophages and DSS-induced colitis. Furthermore, NED treatment significantly decreased FITC-dextran permeability in DSS-induced colitis. NED treatment enhanced tight junction protein expression (claudin-1, 3, 7, and occludin). Time-dependent increases in transepithelial electrical resistance (TEER) measurements reflect the formation of healthy tight junctions in the Caco-2 monolayer. LPS-stimulated Caco-2 showed a significant decrease in TEER. However, NED pre-treatment significantly prevented the fall in TEER measurements, indicating its protective role. In conclusion, NED significantly decreased MAPK and NF-κB signaling pathways and decreased tight junction permeability by enhancing epithelial tight junction protein expression. Full article

(This article belongs to the Special Issue Anti-inflammatory Activities of Natural Compounds)

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12 pages, 4489 KiB

Open AccessArticle

Traditional Chinese Medicine Rhodiola Sachalinensis Borissova from Baekdu Mountain (RsB^BM) for Rheumatoid Arthritis: Therapeutic Effect and Underlying Molecular Mechanisms

by Yinghui Ma, Jinbei Zhang, Huan Yu, Yanfei Zhang, Huifeng Zhang, Chengyi Hao, Lili Zuo, Nianqiu Shi and Wenliang Li

Molecules 2022, 27(18), 6058; https://doi.org/10.3390/molecules27186058 - 16 Sep 2022

Cited by 5 | Viewed by 2054

Abstract

The lack of effective rheumatoid arthritis (RA) therapies is a persistent challenge worldwide, prompting researchers to urgently evaluate traditional Chinese medicines (TCMs) as potential clinical RA treatments. The present investigation was conducted to evaluate the therapeutic effects and potential molecular mechanisms of the [...] Read more.

The lack of effective rheumatoid arthritis (RA) therapies is a persistent challenge worldwide, prompting researchers to urgently evaluate traditional Chinese medicines (TCMs) as potential clinical RA treatments. The present investigation was conducted to evaluate the therapeutic effects and potential molecular mechanisms of the active components isolated from TCM Rhodiola sachalinensis Borissova from Baekdu Mountain (RsB^BM) using an experimental adjuvant arthritis model induced by injection of rats with Freund’s complete adjuvant. After induction of the adjuvant arthritis rat model, the extract-treated and untreated groups of arthritic rats were evaluated for RsB^BM therapeutic effects based on comparisons of ankle circumferences and ELISA-determined blood serum inflammatory factor levels (TNF-α, IL-1β, and PGE2). In addition, the joint health of rats was evaluated via microscopic examination of hematoxylin-eosin-stained synovial tissues. Furthermore, to explore whether NF-κB and RANK/RANKL/OPG signaling pathways participated in observed therapeutic effects from a molecular mechanistic viewpoint, mRNA and protein levels related to the expression of nuclear factor kappa-B (NF-κB), osteoprotegerin (OPG), and receptor activator of nuclear factor kappa-Β ligand (RANKL) were analyzed via quantitative RT-PCR and Western blot analysis, respectively. Treatment of arthritic rats with the extract of RsB^BM was shown to reduce ankle swelling, reduce blood serum levels of inflammatory factors, and alleviate arthritis-associated synovial inflammation and joint damage. Moreover, an RsB^BM 50% ethanol extract treatment inhibited bone destruction by up-regulating OPG-related mRNA and protein expression and down-regulating RANKL-related mRNA and protein expression, while also reducing inflammation by the down-regulating of the NF-κB pathway activity. The results clearly demonstrated that the extract of RsB^BM alleviated adjuvant arthritis-associated joint damage by altering activities of inflammation-associated NF-κB and the RANK/RANKL/OPG signaling pathways. Due to its beneficial effects for alleviating adjuvant arthritis, this RsB^BM 50% ethanol extract should be further evaluated as a promising new therapeutic TCM treatment for RA. Full article

(This article belongs to the Special Issue Anti-inflammatory Activities of Natural Compounds)

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14 pages, 3397 KiB

Open AccessArticle

Activation of Nrf2 by Esculetin Mitigates Inflammatory Responses through Suppression of NF-κB Signaling Cascade in RAW 264.7 Cells

by Thanasekaran Jayakumar, Chun-Jen Huang, Ting-Lin Yen, Chih-Wei Hsia, Joen-Rong Sheu, Periyakali Saravana Bhavan, Wei-Chieh Huang, Cheng-Ying Hsieh and Chih-Hsuan Hsia

Molecules 2022, 27(16), 5143; https://doi.org/10.3390/molecules27165143 - 12 Aug 2022

Cited by 15 | Viewed by 2008

Abstract

Inflammation is a major root of several diseases such as allergy, cancer, Alzheimer’s, and several others, and the present state of existing drugs provoked researchers to search for new treatment strategies. Plants are regarded to be unique sources of active compounds holding pharmacological [...] Read more.

Inflammation is a major root of several diseases such as allergy, cancer, Alzheimer’s, and several others, and the present state of existing drugs provoked researchers to search for new treatment strategies. Plants are regarded to be unique sources of active compounds holding pharmacological properties, and they offer novel designs in the development of therapeutic agents. Therefore, this study aimed to explore the anti-inflammatory mechanism of esculetin in lipoteichoic acid (LTA)-induced macrophage cells (RAW 264.7). The relative expression of inducible nitric oxide synthase (iNOS), nitric oxide (NO) production and COX-2 expression were intensified in LTA-induced RAW cells. The phosphorylation status of mitogen-activated protein kinases (extracellular signal-regulated kinase (ERK)1/2, p38 MAPK, and c-Jun N-terminal kinase (JNK)) and nuclear factor kappa B (NF-κB) p65 were detected by using Western blot assay. The nuclear translocation of p65 was assessed by confocal microscopic image analysis. Esculetin significantly and concentration-dependently inhibited LTA-induced NO production and iNOS expression, but not COX-2 expression, in RAW cells. Esculetin was not effective in LTA-induced MAPK molecules (ERK, p38 and JNK). However, esculetin recovered LTA-induced IκBα degradation and NF-κB p65 phosphorylation. Moreover, esculetin at a higher concentration of 20 µM evidently inhibited the nuclear translocation of NF-κB p65. At the same high concentration, esculetin augmented Nrf2 expression and decreased DPPH radical generation in RAW 264.7 cells. This study exhibits the value of esculetin for the treatment of LTA-induced inflammation by targeting NF-κB signaling pathways via its antioxidant properties. Full article

(This article belongs to the Special Issue Anti-inflammatory Activities of Natural Compounds)

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9 pages, 1731 KiB

Open AccessArticle

Anti-Inflammatory Effect of Protopine through MAPK and NF-κB Signaling Regulation in HepG2 Cell

by MinGyu Kim, Hyuck Kim and Hojun Kim

Molecules 2022, 27(14), 4601; https://doi.org/10.3390/molecules27144601 - 19 Jul 2022

Cited by 3 | Viewed by 1854

Abstract

Protopine is a substance used for hemostasis with an anti-inflammatory action and is one of the substances that are actively undergoing experiments to confirm their utility as anticancer agents. This study examined the molecular changes in the cellular signaling pathways associated with inflammatory [...] Read more.

Protopine is a substance used for hemostasis with an anti-inflammatory action and is one of the substances that are actively undergoing experiments to confirm their utility as anticancer agents. This study examined the molecular changes in the cellular signaling pathways associated with inflammatory responses in phorbol 12-myristate 13 acetate (PMA)-induced human hepatocellular carcinoma cell line (Hep G2). The inhibition of PMA-induced phosphorylation of I-κB in HepG2, the effect of protopine on the MAPK signals, the inhibition of COX-2 activity, and the inhibition of MMP-9 as a medium of inflammatory response were evaluated by Western blot and qPCR. The effect of protopine on the survival rates in HepG2 cells was evaluated and found to be stable to a processing concentration of up to 40μM. Subsequent Western blot analyses showed that protopine blocks the transfer of the MAPKs cell signals induced by PMA and the transfer of the subunit of the nuclear factor-kappa B (NF-κB) to the nucleolus. Protopine inhibited the kappa alpha (I-κBα) phosphorylation in the cytosol and blocked PMA-induced inflammation via COX-2 activity inhibition. The expression of MMP-9 at the gene and protein levels, which is associated with cell migration and metastasis, was reduced by protopine. Full article

(This article belongs to the Special Issue Anti-inflammatory Activities of Natural Compounds)

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Review

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22 pages, 827 KiB

Open AccessReview

Natural-Product-Derived Adjunctive Treatments to Conventional Therapy and Their Immunoregulatory Activities in Triple-Negative Breast Cancer

by Lea Ling-Yu Kan, Ben Chung-Lap Chan, Ping-Chung Leung and Chun-Kwok Wong

Molecules 2023, 28(15), 5804; https://doi.org/10.3390/molecules28155804 - 01 Aug 2023

Cited by 1 | Viewed by 1436

Abstract

Triple-negative breast cancer (TNBC) is an invasive and persistent subtype of breast cancer that is likely to be resistant to conventional treatments. The rise in immunotherapy has created new modalities to treat cancer, but due to high costs and unreliable efficacy, adjunctive and [...] Read more.

Triple-negative breast cancer (TNBC) is an invasive and persistent subtype of breast cancer that is likely to be resistant to conventional treatments. The rise in immunotherapy has created new modalities to treat cancer, but due to high costs and unreliable efficacy, adjunctive and complementary treatments have sparked interest in enhancing the efficacy of currently available treatments. Natural products, which are bioactive compounds derived from natural sources, have historically been used to treat or ameliorate inflammatory diseases and symptoms. As TNBC patients have shown little to no response to immunotherapy, the potential of natural products as candidates for adjuvant immunotherapy is being explored, as well as their immunomodulatory effects on cancer. Due to the complexity of TNBC and the ever-changing tumor microenvironment, there are challenges in determining the feasibility of using natural products to enhance the efficacy or counteract the toxicity of conventional treatments. In view of technological advances in molecular docking, pharmaceutical networking, and new drug delivery systems, natural products show promise as potential candidates in adjunctive therapy. In this article, we summarize the mechanisms of action of selected natural-product-based bioactive compounds and analyze their roles and applications in combination treatments and immune regulation. Full article

(This article belongs to the Special Issue Anti-inflammatory Activities of Natural Compounds)

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