Screening of phytochemical compounds of Tinospora cordifolia for their inhibitory activity on SARS-CoV-2: an in silico study.

In the present study, we explored phytochemical constituents of Tinospora cordifolia in terms of its binding affinity targeting the active site pocket of the main protease (3CL pro) of SARS-CoV-2 using molecular docking study and assessed the stability of top docking complex of tinosponone and 3CL pro using molecular dynamics simulations with GROMACS 2020.2 version. Out of 11 curated screened compounds, we found the significant docking score for tinosponone, xanosporic acid, cardiofolioside B, tembetarine and berberine in Tinospora cordifolia. Based on the findings of the docking study, it was confirmed that tinosponone is the potent inhibitor of main protease of SARS-CoV-2 with the best binding affinity of -7.7 kcal/mol. Further, ADME along with toxicity analysis was studied to predict the pharmacokinetics and drug-likeness properties of five top hits compounds. The molecular dynamics simulation analysis confirmed the stability of tinosponone and 3CL pro complex with a random mean square deviation (RMSD) value of 0.1 nm. The computer-aided drug design approach proved that the compound tinosponone from T. cordifolia is a potent inhibitor of 3CL main protease of SARS-CoV-2. Further, the in vitro and in vivo-based testing will be required to confirm its inhibitory effect on SARS-CoV-2.Communicated by Ramaswamy H. Sarma.

Bioactive molecules of probiotic bacteria and their mechanism of action: a review.

The bacteria residing in the gut environment do play a pivotal role in metabolic activities of the host. The metabolites produced by these bacteria affect the physiology and health of the host. The gut bacteria are exposed to environmental conditions where multiple factors such as lifestyle, stress, antibiotics, host genetics and infections have an influence on them. In case of pathogenesis of a disease, the gut bacterial composition is altered which leads to a diseased state. This stage is due to colonization of bacterial pathogens in the gut environment. The pathological condition can be alleviated by administering probiotic strains into the gut environment. The probiotic strains produce therapeutic molecules such as amino acids, vitamins, bacteriocins, enzymes, immunomodulatory compounds and short-chain fatty acids. This review discusses recent evidences of the impact of bioactive molecules produced by probiotic bacteria and their mechanism of action in the gut environment to maintain homeostasis and health of the host without any effect on beneficial bacteria sharing the same niche. In addition, the manufacturing challenges of probiotic products for various applications are discussed here.