West African medicinal plants and their constituent compounds as treatments for viral infections, including SARS-CoV-2/COVID-19.

OBJECTIVES: The recent emergence of the COVID-19 pandemic (caused by SARS-CoV-2) and the experience of its unprecedented alarming toll on humanity have shone a fresh spotlight on the weakness of global preparedness for pandemics, significant health inequalities, and the fragility of healthcare systems in certain regions of the world. It is imperative to identify effective drug treatments for COVID-19. Therefore, the objective of this review is to present a unique and contextualised collection of antiviral natural plants or remedies from the West African sub-region as existing or potential treatments for viral infections, including COVID-19, with emphasis on their mechanisms of action. EVIDENCE ACQUISITION: Evidence was synthesised from the literature using appropriate keywords as search terms within scientific databases such as Scopus, PubMed, Web of Science and Google Scholar. RESULTS: While some vaccines and small-molecule drugs are now available to combat COVID-19, access to these therapeutic entities in many countries is still quite limited. In addition, significant aspects of the symptomatology, pathophysiology and long-term prognosis of the infection yet remain unknown. The existing therapeutic armamentarium, therefore, requires significant expansion. There is evidence that natural products with antiviral effects have been used in successfully managing COVID-19 symptoms and could be developed as anti-COVID-19 agents which act through host- and virus-based molecular targets. CONCLUSION: Natural products could be successfully exploited for treating viral infections/diseases, including COVID-19. Strengthening natural products research capacity in developing countries is, therefore, a key strategy for reducing health inequalities, improving global health, and enhancing preparedness for future pandemics.

Spermicidal Constituents of Ethanolic Extract of Sacoglottis gabonensis Stem Bark.

AIM: To isolate the spermicidal constituents of Sacoglottis gabonensis. MATERIALS AND METHODS: The ethanolic extract with partitioned fractions of Sacoglottis gabonensis stem bark were subjected to sperm immobilization assay. The most active EtOAc fraction was further purifi ed by column and Semi-Preparative High Performance Liquid Chromatography to give compounds which were characterized by spectroscopic methods (UV, LC/MS, and NMR). The compound(s) was also tested for sperm immobilization activity. RESULTS: The ethanolic extract showed 100% signifi cant (p < 0.05) sperm immobilization activity at a concentration of 30 mg/mL at 20 s compared to both negative and positive controls. The most active ethyl acetate fraction yielded methyl 3,5-dihydroxy-4-methoxybenzoate, eriodictyol and bergenin. Bergenin had 100% sperm immobilization activity at 20 mg/mL in 60 s which was signifi cant (p < 0.05) also when compared to the positive and negative control while methyl 3,5-dihydroxy- 4-methoxybenzoate, eriodictyol were not active. CONCLUSION: The active spermicidal constituent in Sacoglottis gabonensis stem bark extract is bergenin. However, methyl 3,5-dihydroxy-4-methoxybenzoate and eriodictyol showed no activity. This plant is known for its aphrodisiac action; hence, caution may have to be exercised in its use because of its spermicidal eff ect.