Phytochemical profile and antimicrobial activity of the leaves and stem bark of Symphonia globulifera L.f. and Allophylus abyssinicus (Hochst.) Radlk.

INTRODUCTION: Symphonia globulifera and Allophylus abyssinicus are used in the management of skin rashes and sores, cough, malaria, digestive diseases, stomach ache, wounds and helminthic infections among others in Uganda, Kenya, Ethiopia, Cameroon. This study aimed at determining the phytochemical profile and antimicrobial activity of these two plants. METHODS: The stem bark and leaves of both plants were collected from Bwindi Impenetrable National Park and air-dried under shade at room temperature. Cold maceration, decoction and infusion with methanol, water and ethyl acetate as solvents were used in phytochemical extraction. Preliminary qualitative screening and thin layer chromatography were used for phytochemical profiling. Antimicrobial activity was analysed by agar well diffusion assay, broth macro-dilution assay and fractional inhibition concentration index (FICI). RESULTS: The leaves and stem bark of both plants have a diverse set of phytochemical compounds of variable polarity including, tannins, alkaloids, flavonoids, saponins, quinones and anthraquinones among others. Generally, methanol and water extracts of S. globulifera and A. abyssinicus had in-vitro bactericidal activity against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa but weak fungistatic activity against Candida albicans. Allophylus abyssinicus leaf water and S. globulifera leaf methanol extract combination had a synergistic activity (ΣFICI = 0.37) against S. aureus. Similarly, A. abyssinicus stem bark water extract and A. abyssinicus leaf water extract combination had an additive effect (ΣFICI = 1) against P. aeruginosa. CONCLUSION: The leaves and stem bark crude extracts of S. globulifera and A. abyssinicus possess a wide range of bioactive phytochemical compounds but have weak antimicrobial activity against S. aureus, E. coli, P. aeruginosa and C. albicans.

Potential Benefits of Antiviral African Medicinal Plants in the Management of Viral Infections: Systematic Review.

Background: Viruses cause various human diseases, some of which become pandemic outbreaks. This study synthesized evidence on antiviral medicinal plants in Africa which could potentially be further studied for viral infections including Coronavirus disease 2019 (COVID-19) treatment. Methods: PUBMED, CINAHIL, Scopus, Google Scholar, and Google databases were searched through keywords; antiviral, plant, herb, and Africa were combined using "AND" and "OR". In-vitro studies, in-vivo studies, or clinical trials on botanical medicine used for the treatment of viruses in Africa were included. Results: Thirty-six studies were included in the evidence synthesis. Three hundred and twenty-eight plants were screened for antiviral activities of which 127 showed noteworthy activities against 25 viral species. These, were Poliovirus (42 plants), HSV (34 plants), Coxsackievirus (16 plants), Rhinovirus (14plants), Influenza (12 plants), Astrovirus (11 plants), SARS-CoV-2 (10 plants), HIV (10 plants), Echovirus (8 plants), Parvovirus (6 plants), Semiliki forest virus (5 plants), Measles virus (5 plants), Hepatitis virus (3 plants), Canine distemper virus (3 plants), Zika virus (2 plants), Vesicular stomatitis virus T2 (2 plants). Feline herpesvirus (FHV-1), Enterovirus, Dengue virus, Ebola virus, Chikungunya virus, Yellow fever virus, Respiratory syncytial virus, Rift Valley fever virus, Human cytomegalovirus each showed sensitivities to one plant. Conclusion: The current study provided a list of African medicinal plants which demonstrated antiviral activities and could potentially be candidates for COVID-19 treatment. However, all studies were preliminary and in vitro screening. Further in vivo studies are required for plant-based management of viral diseases.