Drugs Drug Candidates, Volume 2, Issue 2 (June 2023) – 15 articles

Inflammation is an essential defense mechanism against harmful stimuli. However, uncontrolled inflammatory mechanisms culminate in disturbed responses that contribute to multiple serious diseases. Besides common synthetic drugs, there is a growing interest in optimizing the use of natural products as therapeutic or protective supplements against inflammatory disorders. Black cumin seed (BCS), or Nigella sativa (Family Ranunculaceae), is widely used as a health-supportive herb in the Middle East, Far East and West Asia. BCS is a rich source of phytochemicals, and studies have reported its promising effects against a variety of metabolic, proliferative, respiratory, and neurological disorders associated with disrupted inflammatory pathways. This review presents an updated comprehensive assessment of BCS’s effects against various inflammatory disorders and highlights the role of BCS’s bioactive constituents in inflammation and oxidative stress pathways. Moreover, it outlines the future possibilities for enhancing therapeutic activity through efficient pharmaceutical formulations. Thorough analysis of international research studies published between the years 1998 and 2023 reveals the promising anti-inflammatory potential of BCS’s bioactive constituents through modulating inflammation and crucial oxidative stress players in inflammatory disorders. Thus, the bioactive constituents of BCS can be further boosted by updated technologies such as nano-incorporation for the improved management of inflammatory diseases. Full article

The goal of this research was to create an antibacterial formulation from Scinus areira essential oil (EO) that could spread in water. To achieve this, we developed liposomal formulations of DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine) or DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine) that encapsulated the EO. In addition, we utilized the EO as a reducing and stabilizing agent to synthesize silver nanoparticles (AgNPs). The nanoformulations were characterized by determining their size and zeta potential. In the case of liposomal formulations, chemical composition, and encapsulation efficiency were also determined. Furthermore, antimicrobial activity studies against Gram-positive and Gram-negative model bacteria were carried out for both kinds of formulations. The results obtained showed the successful encapsulation of the S. areira EO in multilamellar liposomes of phosphatidylcholine with high efficiency. DPPC liposomes have proven to be a better encapsulation system, retaining more monoterpenes from the EO and therefore presenting antimicrobial activity against S. aureus with an minimal inhibitory concentration (MIC) value of 3 mg/mL of EO. On the other hand, it was also possible to obtain AgNPs by using S. areira EO, which showed antimicrobial activity against S. aureus and E. coli at low concentrations of EO, with MIC values of 6.68 µg/mL and 3.4 µg/mL of silver, respectively. The data obtained will contribute to enhancing the biotechnological value of natural products derived from native plant species in Argentina. This will be achieved through the generation of novel formulations with antibacterial activity and potential bioavailability. Full article

Opioids such as morphine are the first choice in acute and chronic pain treatment. However, they lead to addiction. Several studies have searched (i) to find a molecule that can replace morphine use or (ii) to reduce its adverse effects. This work aimed to evaluate whether (–)-Borneol [(–)-BOR], a bicyclic monoterpene, in doses of 25, 50, and 100 mg/kg (i.p.), has an antiaddictive effect on morphine (5 mg/kg, i.p.) and reduces its withdrawal symptoms precipitated by naloxone (8 mg/kg, i.p.) in Swiss mice. Furthermore, the (–)-BOR genotoxic potential was also investigated by the comet assay. The antiaddictive effect of (–)-BOR was evaluated by the conditioned preference place (CPP). The CPP was induced by morphine administration during the conditioning phase. The effects of (–)-BOR on the rewarding characteristics of morphine were tested in mice with the administration of (–)-BOR, naloxone, or vehicle (NaCl 0.9%), 30 min before morphine. This work also investigated the (–)-BOR effect on morphine withdrawal symptoms precipitated by naloxone. Morphine withdrawal symptoms were induced by administering morphine twice daily for 5 days, precipitated by naloxone administration on the sixth day. The effect of (–)-BOR on reducing morphine withdrawal symptoms was evaluated in mice that received (–)-BOR before daily morphine administration. Finally, the comet assay was performed to assess the DNA damage degree caused by the (–)-BOR (100 mg/kg, i.p.) administration. The comet assay was performed on peripheral blood taken from the tail of each animal. Cyclophosphamide (50 mg/kg, i.p.) was used to induce DNA damage. After starting the protocol, analyses were performed for 4 h (acute effect) and 24 h (repair effect). The (–)-BOR (100 mg/kg, i.p.) significantly attenuated (*** p < 0.001) the acquisition of morphine-induced CPP and reduced only the jumping behavior in the morphine withdrawal model. The best-studied dose was 100 mg/kg, being evaluated, then, in the comet assay. (–)-BOR at 100 mg/kg did not show the genotoxic effect when compared with the cyclophosphamide group (CYCLO, 50 mg/kg, i.p.) after 4 h or 24 h, a period that corresponded to the repair time of DNA fragmentation. The study showed that (–)-BOR attenuated the acquisition of CPP by morphine and made opioid withdrawal milder. In the comet assay, although (–)-BOR caused DNA damage, this damage was significantly less than the damage by CYCLO, at either 4 h or 24 h after the treatments. Full article

Chagas disease is caused by the parasite protozoan Trypanosoma cruzi (T. cruzi) and affects millions of people in over 21 countries in around the world. The main forms of treatment of this disease, benznidazole and nifurtimox, present low cure rates in the chronic phase and often have serious side effects. Herein, we describe the evaluation of the trypanocidal activity of arylsulfonamides. The arylsulfonamides were evaluated in vitro against the amastigote and trypomastigote forms of the parasite. An enantiomerically pure example of arylsulfonamide was also tested. The initial results suggest that the arylsulfonamides evaluated act as DNA binding agents. A moderate activity was monitored against the intracellular forms of T. cruzi, with the best compound exhibiting an IC₅₀ value at 22 μM and a selectivity index of 120. However, the level of activity was not favorable for progressing towards in vivo studies for Chagas disease. Full article

Exportin 1 (XPO1) is a crucial molecule of nucleocytoplasmic transport. Among others, it exports molecules important for oncogenesis from the nucleus to the cytoplasm. The expression of XPO1 is increased in numerous malignancies, which contributes to the abnormal localization of tumor suppressor proteins in the cytoplasm and subsequent cell cycle dysregulation. Selective inhibitors of nuclear export (SINEs) are novel anticancer agents that target XPO1, arrest tumor suppressor proteins in the nucleus, and induce apoptosis in cancer cells. Selinexor, a first-in-class SINE, has already been approved for the treatment of relapsed/refractory multiple myeloma and relapsed/refractory diffuse large B cell lymphoma not otherwise specified. It has also been proven effective in relapsed/refractory and previously untreated acute myeloid leukemia patients. In addition, numerous studies have yielded promising results in other malignancies of the hematopoietic system and solid tumors. However, future clinical use of selinexor and other SINEs may be hampered by their significant toxicity. Full article

Bioactive compounds against SARS-CoV-2 targets could be potential treatments for COVID-19. Inhibitors of the receptor-binding domain (RBD) on the viral spike protein can block its binding to the human angiotensin-converting enzyme type II (ACE2) receptor. This study presents ligands based on natural products and synthetic compounds, targeting multiple N501/Y501 RBDs, besides RBD-ACE2, over different regions. The selected compounds were evaluated by docking using consensus scoring, pharmacokinetics/toxicological analyses, and molecular dynamics. Additionally, N501/Y501 RBD-ACE2 interaction properties and RBD–ligand complexes were compared. We identified that coenzyme Q10, 1-stearoyl-2-arachidonoylglycerol, and palmitone showed the greatest RBD interactions. Targeting specific residues (in particular, tyrosine) in the C-, N-terminal, and central RBD sites promoted more stable protein–ligand interactions than in the N-terminal region only. Our results indicate that the molecules had more energetically favorable interactions with residues from distinct RBD regions rather than only interacting with residues in the N-terminal site. Moreover, the compounds might better interact with mutated N501Y than N501 RBDs. These hits can be optimized to leads and investigated through QSAR models and biological assays to comprehend mechanisms better. Altogether, such strategies may anticipate antiviral strategies if or when future variants and other CoVs arise. Full article

The present study was designed to establish the phenolic profile and explore the potential lipid-lowering effect of two Moroccan date fruit varieties (Majhoul and Bousrdoun). HPLC-DAD has been used for phenolic profiling. Lipid peroxidation was measured in terms of thiobarbituric acid-reactive substances (TBARS) by using egg yolk homogenate as lipid-rich media. The anti-hyperlipidemic effect of the methanolic extract was examined using both models Triton-WR-1339 and chronic high-fat-diet-induced hyperlipemic rats. Further, the serum lipid profile was determined. The HPLC-DAD analysis revealed the presence of seven phenolic acids and three flavonoids, of which gallic, caffeic acids and rutin were found to be the most abundant compounds. The gathered results indicate that rats treated with both varieties showed a significant decrease in serum total cholesterol, triglycerides, and low-density lipoprotein cholesterol levels as well as an increase in high-density lipoprotein cholesterol levels compared with Triton and high-fat diet controls. Moreover, a significant decrease in body weight was observed in the date-treated groups when compared to the hyperlipidemic control group. A thiobarbituric acid reactive substances test showed that these extracts significantly inhibited lipid peroxidation. Bousrdoun, which showed the highest lipid-lowering effects, is the one that displayed the greatest inhibition of lipid peroxidation and contains the largest amount of caffeic, p-coumaric, gallic, vanillic acids, rutin and luteolin. Accordingly, dates could be used as a potential functional food, which may be used to prevent lipid disorders and oxidation. Full article

Cancer, also known as malignant tumour or neoplasm, is a leading cause of death worldwide. One distinct feature from normal cells is that cancerous cells often overexpress protein on the cell membrane—for instance, the overexpression of human epidermal growth factor receptor 2. The expression of a specific protein on the cancerous cell surface acts as a marker that differentiates the normal cell and facilitates the recognition of cancerous cells. An emerging anticancer treatment, Antibody–Drug Conjugates (ADCs), utilises this unique feature to kill cancerous cells. ADCs consist of an antibody linked with a cytotoxic payload, mainly targeting the antigen found on cancerous cells. This design can increase the specificity in delivering the cytotoxin to the drug target, thus increasing the drug efficacy and reducing the side effect of cancer treatment due to off-target toxicities. There are tremendous quantities of clinical trials conducted to evaluate the safety and effectiveness of this magic drug in treating different types of cancers. However, only 12 ADCs have been approved by the FDA until now. This review provides the principles of ADCs and highlights the ADCs that FDA has approved. In addition, some of the ADCs that undergo clinical trials are discussed in this review. The application of computational techniques in addressing ADCs’ challenges and neoantigen-targeted cancer vaccines is also highlighted. Although ADCs have been seen as promising magic drugs in cancer treatment, the problems such as toxicity, the stability of the linker, the specificity of an antibody with antigen, and so on, remain a challenge in developing ADCs. Full article

Cucurbitacins are secondary metabolites that are commonly found in the Cucurbitacae family. Many biological properties have been reported for cucurbitacins, including anti-inflammatory, antioxidant, antiviral, anti-malaria, and anticancer properties. While studies for the anticancer property of cucurbitacins focus mostly on the cell-cycle progression and apoptosis, no study has considered the effect of cucurbitacin on other cancer behaviors. Here, we report cell-proliferation-based drug testing on random herbal extracts leading to the identification of cucurbitacin B as an anticancer compound. Interestingly, cucurbitacin B had no effect on the proliferation of rat embryonic myoblast cells. We also found that cucurbitacin B significantly reduced the invasiveness of at least two highly metastatic breast cancer and melanoma cells. Using known cancer stem-cell markers, we observed a significant reduction of the melanoma stem cells. Molecularly, cucurbitacin B caused reduction of the metastasis-promoting gene Snail in melanoma and one of the cancer stem cell markers, ALDH1A1 (aldehyde dehydrogenase 1 A1), in breast cancer. Finally, we report the potential toxicity of cucurbitacin B in developing skin tissue and the olfactory organ using zebrafish embryo. In summary, our study suggests the potential use of cucurbitacin B for cancer metastasis and relapse treatment. Full article

Resistance to the existing arsenal of therapeutic agents significantly impedes successful drug therapy. One approach to combat this burgeoning global crisis is to provide novel and more effective clinical agents. Terrestrial plants have long been exploited as a source of novel drug candidates. In this line, the endemic floral diversity of the Republic of Mauritius cannot be ignored. However, developing drugs from these plants is a multi-stepped, lengthy process that requires multistakeholder involvement from scientists, policymakers, and conservationists as well as the local community. This review aims at summarising the reported bioactivities of the endemic plants. The electronic databases were searched using relevant keywords. A total of 33 original research articles were considered. A repertoire of 17 families comprising 53 Mauritian-endemic plant species has been reported for their anticancer activity (n = 20), antimicrobial activity (n = 36), antidiabetic activity (n = 3), and clinical enzyme inhibitory activity (n = 25). Five plant extracts, namely Acalypha integrifolia, Labourdonaisia glauca, Eugenia tinifolia, Syzygium coriaceum, and Terminalia bentzoë, have been earmarked as worthy to be further investigated for their anticancer potential. Moreover, two Psiadia species, namely P. arguta and P. terebinthina, have shown promising antimicrobial activity. This review highlights the extracts’ potent anticancer and antimicrobial activities, focussing on their proposed mechanism of action. Moreover, the need for metabolite profiling for identifying bioactive ingredient(s) is emphasised. Full article

Drug discovery and repositioning are important processes for the pharmaceutical industry. These processes demand a high investment in resources and are time-consuming. Several strategies have been used to address this problem, including computer-aided drug design (CADD). Among CADD approaches, it is essential to highlight virtual screening (VS), an in silico approach based on computer simulation that can select organic molecules toward the therapeutic targets of interest. The techniques applied by VS are based on the structure of ligands (LBVS), receptors (SBVS), or fragments (FBVS). Regardless of the type of VS to be applied, they can be divided into categories depending on the used algorithms: similarity-based, quantitative, machine learning, meta-heuristics, and other algorithms. Each category has its objectives, advantages, and disadvantages. This review presents an overview of the algorithms used in VS, describing them and showing their use in drug design and their contribution to the drug development process. Full article

Acquired bacterial resistance against several antibiotics has severely impaired the drug treatment regime. Multidrug-resistant Staphylococcus aureus (MDRSA) causes several life-threatening human pathologies. The introduction of novel antibiotics is a tedious process. Therefore, we have introduced glycyrrhizin (Gly) as a bioenhancer of norfloxacin (Nor), which showed synergistic interactions and a robust drug response. The drug resistance reversal potential of Gly against MDRSA was monitored. Gly and GlyNor (glycyrrhizin + norfloxacin) were used for spectrofluorometer and flow cytometry analysis for the measurement of free radicals and its effect upon cell membranes and macromolecules. Morphological analysis was carried out with the help of SEM. qRT-PCR analysis was conducted for gene regulation. Gly was observed to lower the MIC (minimum inhibitory concentration) of different groups of antibiotics up to 64-fold against MDRSA. GlyNor exerted oxidative stress, as evidenced by the measurement of reactive oxygen species (ROS) and their effect upon cell components. Gly and GlyNor showed membrane damage potential. The expression analysis of oxidative-related and MDR genes showed the up- and downregulation of these genes, respectively. GlyNor significantly lengthened post-antibiotic effects (PAE) and showed reduced mutation frequency rate (MFR). The synergistic bioenhancer properties of Gly with Nor and their enhanced ROS generation against MDRSA are reported for the first time in this study. Severe oxidative stress caused membrane damage, DNA fragmentation, transcriptional changes, and bacterial cell death. We strongly believe this could be a potential measure against rapidly evolving MDRSA. Full article

Pseudomonas aeruginosa, a life-threatening bacteria listed as a priority pathogen by World Health Organization WHO, is known to cause severe nosocomial infections and fatality in immunocompromised individuals through its quorum sensing (QS) mediated biofilm formation. P. aeruginosa’s antibiotic-resistant biofilms are highly challenging to the existing antibiotic treatment options. There is an urgent clinical need to develop novel alternative therapeutic molecules such as antibiofilm and antiquorum sensing agents to counter the emergence of an unprecedented pace of antibiotic resistance of pathogens. In this context, a library of seventy 3-amidocoumarin derivatives was designed, and docking studies were performed against the P. aeruginosa LasR receptor using AutoDock 4.0. Based on docking results, a final series of sixteen 3-amidocoumarin derivatives (4a–p) were synthesized and evaluated for antibiofilm activity in vitro. Eight compounds significantly inhibited the formation of P. aeruginosa PAO1 biofilm. Compounds 4f, 4l and 4o showed maximum % inhibition in antibiotic-resistant P. aeruginosa PAO1 biofilm formation in the range of 80% to 86%. Further, the structure–activity relationship (SAR) studies revealed that the presence of electron-donating and bromo substituents at benzamido and coumarin moieties, respectively, effectively enhances the antibiofilm activity. In addition, the binding interactions between the synthesized compounds and active sites of the LasR QS receptor (Protein Data Bank Code: 2uv0) in P. aeruginosa were also investigated by molecular docking. The high binding affinities indicate that these compounds might be suitable for development into potent inhibitors of QS and biofilm disruptors. Full article

In recent decades, acceptance of nanoparticles (NPs) in therapeutic applications has increased because of their outstanding physicochemical features. By overcoming the drawbacks of conventional therapy, the utilization of metal NPs, metal-oxide, or metal supported nanomaterials have shown to have significant therapeutic applications in medicine. This is proved by a lot of clinical and laboratory investigations that show improved treatment outcomes, site-specific drug delivery, and fewer side effects compared to traditional medicine. The metal NPs interaction with living cells (animal and plant) showed many ways to develop therapeutic models with the NPs. Despite all of the advancements that science has achieved, there is still a need to find out their performance for long-term use to solve modern challenges. In this regard, the present documentation reviews some potential metals, including silver (Ag), gold (Au), zinc (Zn), copper (Cu), iron (Fe), and nickel (Ni) NPs, as therapeutic agents in various areas such as anticancer, antimicrobial, antidiabetic, and applicable for the treatment of many other diseases. Depending on the outstanding ongoing research and practical trials, metal-based NPs can be considered the hope of prospective modern therapeutic areas. Full article

Liver cancer is a high mortality cancer, and its increasing prevalence is a concern worldwide. Current treatment modalities for liver cancer include chemotherapy and immunotherapy. These therapies provide symptomatic relief and help prolong the lives of patients but are not an absolute cure. In this paper we have explored an alternative approach, drug repurposing, to identify drugs for treating liver cancer. Databases like PubMed, ScienceDirect, and JSTOR were used for literature mining, and the PRISMA 2020 systemic review guidelines were followed to identify drugs that have been trialed for repurposing in liver cancer. The protein receptors and target protein classes of all the drugs were identified using the Swiss Target Prediction tool. Further, the biological interactions and pathways followed by the drugs were studied via protein interaction networks using Cytoscape. Molecular pathways such as Bile acid receptor activity, Inosine-5′-monophosphate (IMP) dehydrogenase activity, JUN kinase activity, Nitric-oxide synthase activity, and Mitogen-activated protein (MAP) kinase activity were observed to be influenced by these drugs. The fact that the genes targeted by these repurposed drugs are common with the differentially expressed genes in liver cancer is an excellent starting point to verify the current hypothesis. Full article