Antioxidant and Antiproliferative Activity of Selected Medicinal Plants of Lower Assam, India: An In Vitro and In Silico Study

Screening of phytochemicals as potent inhibitor of 3-chymotrypsin and papain-like proteases of SARS-CoV2: an in silico approach to combat COVID-19

COVID-19 and its causative organism SARS-CoV2 that emerged from Wuhan city, China have paralyzed the world. With no clinically approved drugs, the global health system is struggling to find an effective treatment measure. At this crucial juncture, screening of plant-derived compounds may be an effective strategy to combat COVID-19. The present study investigated the binding affinity of phytocompounds with 3-Chymotrypsin-like (3CLpro) and Papain-like proteases (PLpro) of SARS-CoV2 using in-silico techniques. A total of 32 anti-protease phytocompounds were investigated for the binding affinity to the proteins. Docking was performed in Autodock Vina. Pharmacophore descriptors of best ligands were studied using LigandScout. Molecular dynamics (MD) simulation of apo-protein and ligand-bound complexes was carried out in YASARA software. The druglikeness properties of phytocompounds were studied using ADMETlab. Out of 32 phytochemicals, amentoflavone and gallocatechin gallate showed the best binding affinity to 3CLpro (-9.4 kcal/mol) and PLpro (-8.8 kcal/mol). Phytochemicals such as savinin, theaflavin-3,3-digallate, and kazinol-A also showed strong affinity. MD simulation revealed ligand-induced conformational changes in the protein with decreased surface area and higher stability. The RMSD/F of proteins and ligands showed stability of the protein suggesting the effective binding of the ligand in both the proteins. Both amentoflavone and gallocatechin gallate possess promising druglikeness property. The present study thus suggests that Amentoflavone and Gallocatechin gallate may be potential inhibitors of 3CLpro and PLpro proteins and effective drug candidates for SARS-CoV2. However, the findings of in silico study need to be supported by in vivo studies to establish the exact mode of action.Communicated by Ramaswamy H. Sarma.

Potential Anti-Mycobacterium tuberculosis Activity of Plant Secondary Metabolites: Insight with Molecular Docking Interactions

Tuberculosis (TB) is a recurrent and progressive disease, with high mortality rates worldwide. The drug-resistance phenomenon of Mycobacterium tuberculosis is a major obstruction of allelopathy treatment. An adverse side effect of allelopathic treatment is that it causes serious health complications. The search for suitable alternatives of conventional regimens is needed, i.e., by considering medicinal plant secondary metabolites to explore anti-TB drugs, targeting the action site of M. tuberculosis. Nowadays, plant-derived secondary metabolites are widely known for their beneficial uses, i.e., as antioxidants, antimicrobial agents, and in the treatment of a wide range of chronic human diseases (e.g., tuberculosis), and are known to “thwart” disease virulence. In this regard, in silico studies can reveal the inhibitory potential of plant-derived secondary metabolites against Mycobacterium at the very early stage of infection. Computational approaches based on different algorithms could play a significant role in screening plant metabolites against disease virulence of tuberculosis for drug designing.

In vitro study of the antioxidant, antiproliferative, and anthelmintic properties of some medicinal plants of Kokrajhar district, India

Alstonia scholaris, Cardiospermum halicacabum, Hydrocotyle sibthorpioides, and Hypericum japonicum are important folk medicinal plants used by tribal communities of Bodoland region of Assam to treat helminth infections. Because of their ethnomedicinal values, the present study was designed to investigate the antioxidant, antiproliferative, and anthelmintic activities of the plants. The antioxidant activity was measured by total antioxidant capacity, total phenolics (TPC), total flavonoid (TFC), FRAP, DPPH, ABTS, and TBARS assay. Antiproliferative and apoptosis-inducing activities of plants were conducted in Dalton's lymphoma (DL) cells. Cells were treated for 24 h with different doses (25-200 mg/mL) of plant extracts. Anthelmintic study was conducted by treating the Paramphistomum sp. at different doses of plant extracts. Phytochemical and antioxidant studies showed rich TPC, TFC, and free radical scavenging activity in H. japonicum and H. sibthorpioides. Both the antiproliferative and anthelmintic bioassays showed a dose-dependent efficacy in all plants. H. japonicum showed the strongest anthelmintic activity (LC₅₀ 0.21 mg/mL) followed by H. sibthorpioides (5.36 mg/mL), C. halicacabum (13.40 mg/mL), and A. scholaris (18.40 mg/mL). Evidently, H. sibthorpioides showed the strongest antiproliferative and apoptosis-inducing activities among all the plants. The study observed a positive correlation between the antioxidant properties and antiproliferative and anthelmintic activities of the plants. We, therefore, conclude that the phytocompounds present in the crude extracts along with antioxidant molecules may have combined effects contributing to the antiproliferative and anthelmintic activities of the plants.

Biologically relevant unusual cooperative assemblies and fascinating infinite crown-like supramolecular nitrate–water hosts involving guest complex cations in bipyridine and phenanthroline-based Cu(ii) coordination compounds: antiproliferative evaluation and theoretical studies

Cytotoxicity in cancer cells with structure activity relationship has been explored in Cu(ii) compounds involving biologically relevant cooperative assemblies and fascinating crown-like nitrate–water hosts with guest complex cations.

A pharmacological perspective of banana: implications relating to therapeutic benefits and molecular docking

Banana is one of the most nutritious fruits, as it is rich in carbohydrates, proteins, fatty acids, and minerals. Banana has been used in traditional medicines for managing coughs and colds, ulcers, burns, and diarrhea. Banana contains various bioactive compounds, such as alkaloids, phenols, flavonoids, tannins, and saponins, with reported therapeutic benefits, including antioxidant, anti-diabetic, anti-cancer, anti-inflammatory, and anti-microbial activities. The present review focuses on a comprehensive overview of the nutritional and biological properties and phytochemicals of different species of banana and its different parts. Although detailed characterization of the compounds that are present in many parts of the plant has been carried out, chemical profiling of the seed, pseudostem, and leaves of banana is lacking and requires further exploration. Moreover, the functions of the reported compounds were elucidated using computational tools, supporting their potential role in managing life-threatening diseases and physiological complications.

GC–MS analysis of phytocompounds and antihyperglycemic property of Hydrocotyle sibthorpioides Lam

Hydrocotyle sibthorpioides Lam. is a popular medicinal plant of Assam having several ethnomedicinal values. The present study investigated the metallic content, phytochemical contents, α-amylase, and α-glucosidase enzymes inhibitory property of H. sibthorpioides using in-vitro and in-silico methods. Heavy metal contents were analyzed using Atomic Absorption Spectroscopy. GC–MS was used to analyze the phytochemical compounds of the plant. Enzyme inhibition study was carried out by Spectrophotometry methods. The drug-likeness and toxicity properties of the phytocompounds were studied using SwissADME and ADMETlab databases. Docking and molecular visualizations were performed in AutoDock vina and Discovery studio tools. The study found that the extract of H. sibthorpioides contains a negligible amount of toxic elements. GC–MS analysis detected four compounds from the methanolic extract of the plant. Biochemical study showed considerable α-amylase and α-glucosidase enzyme inhibitory property of the crude extract of H. sibthorpioides. The IC50 of the plant extracts were found to be 1.27 mg/ml and 430.39 µg/ml for α-amylase and α-glucosidase enzymes, respectively. All four compounds were predicted to have potential drug-likeness properties with high cell membrane permeability, intestinal absorption, and less toxic effects. The docking study also showed strong binding affinities between the plant compounds and enzymes. Plant compound C2 showed an almost similar binding affinity with the α-amylase enzyme as compared to standard acarbose. The present study, thus, suggests the antihyperglycemic property of H. sibthorpioides and can be a potential source of antidiabetic drug candidates.