Phyto-Compounds from a Rather Poisonous Plant, Strychnos nuxvomica, Show High Potency Against SARS-CoV-2 RNA-Dependent RNA Polymerase.

BACKGROUND: The establishment of strategy to inhibit the virus replication is an attractive means in combating SARS-CoV-2 infection. OBJECTIVE: We studied phyto-compounds from Strychnos nux-vomica (a poisonous plant) against SARS-CoV-2 RNA-dependent RNA polymerase by computational methods. METHODS: Molecular docking, molecular dynamics (MD) simulation and energetics calculations were employed to elucidate the role of the phyto-compounds. RESULTS: Ergotamine with a binding free energy of -14.39 kcal/mol showed a promising capability in terms of binding affinity and the interaction to conserved motifs, especially the SDD signature sequence. The calculated dissociation constants for ATP, ergotamine, isosungucine and sungucine were 12 µM, 0.072 nM, 0.011 nM and 0.152 nM, respectively. The exhibited kd by these phyto-compounds reflected tens of thousands fold potency as compared to ATP. The binding free energies of sungucine and isosungucine were much lower (-13.93 and -15.55 kcal/mol, respectively) compared to that of ATP (-6.98 kcal/mol). CONCLUSION: Sharing the same binding location as that of ATP and having high binding affinities, Ergotamine, Isosungucine, Sungucine and Strychnine N-oxide could be effective in controlling the SARS-CoV-2 virus replication by blocking the ATP and inhibiting the enzyme function.

In silico screening of therapeutic potentials from Strychnos nux-vomica against the dimeric main protease (Mpro) structure of SARS-CoV-2.

The novel coronavirus also referred to as SARS-CoV-2 causes COVID-19 and became global epidemic since its initial outbreak in Wuhan, China, in December 2019. Research efforts are still been endeavoured towards discovering/designing of potential drugs and vaccines against this virus. In the present studies, we have contributed to the development of a drug based on natural products to combat the newly emerged and life-threatening disease. The main protease (MPro) of SARS-CoV-2 is a homodimer and a key component involved in viral replication, and is considered as a prime target for anti-SARS-CoV-2 drug development. Literature survey revealed that the phytochemicals present in Strychnos nux-vomica possess several therapeutic activities. Initially, in the light of drug likeness laws, the ligand library of phytoconstituents was subjected to drug likeness analysis. The resulting compounds were taken to binding site-specific consensus-based molecular docking studies and the results were compared with the positive control drug, lopinavir, which is a main protease inhibitor. The top compounds were tested for ADME-Tox properties and antiviral activity. Further molecular dynamics simulations and MM-PBSA-based binding affinity estimation were carried out for top two lead compounds' complexes along with the apo form of main protease and positive control drug lopinavir complex, and the results were comparatively analysed. The results revealed that the two analogues of same scaffold, namely demethoxyguiaflavine and strychnoflavine, have potential against Mpro and can be validated through clinical studies.Communicated by Ramaswamy H. Sarma.

Clinical Characteristics and Remedy Profiles of Patients with COVID-19: A Retrospective Cohort Study.

OBJECTIVE: The aim of the study was to identify indicated homeopathic remedies based on the clinical characteristics of coronavirus disease 2019 (COVID-19) patients in India. METHODS: In this retrospective, cohort study, confirmed COVID-19 patients admitted at a COVID Health Centre in New Delhi between April 29 and June 17, 2020 were given conventional and homeopathic treatment. Patients were grouped into mild, moderate or severe categories of disease. Their symptomatologic profiles were analyzed to identify indicated homeopathic medicines. RESULTS: A total of 196 COVID-19 patients were admitted. One hundred and seventy-eight patients had mild symptoms; eighteen patients had moderate symptoms; no patients with severe symptoms were included as they were referred to tertiary care centers with ventilatory support. The mean age of patients with mild symptoms was significantly lower (38.6 years; standard deviation or SD ± 15.8) compared with patients in the moderate category (66.0 years; SD ± 9.09). The most important symptoms identified were fever (43.4%), cough (47.4%), sore throat (29.6%), headache (18.4%), myalgia (17.9%), fatigue (16.8%), chest discomfort (13.8%), chills (12.6%), shortness of breath (11.2%) and loss of taste (10.2%). Twenty-eight homeopathic medicines were prescribed, the most frequently indicated being Bryonia alba (33.3%), Arsenicum album (18.1%), Pulsatilla nigricans (13.8%), Nux vomica (8%), Rhus toxicodendron (7.2%) and Gelsemium sempervirens (5.8%), in 30C potency. CONCLUSION: Data from the current study reveal that Arsenicum album, Bryonia alba, Pulsatilla nigricans, Nux vomica, Rhus toxicodendron and Gelsemium sempervirens are the most frequently indicated homeopathic medicines. A randomized controlled clinical trial based on this finding is the next step.