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The present study reports in vitro anti-sickling activity and phytochemical analyses of the leaves of Ocimum gratissimum. Biological testing revealed that the plant extracts possess antisickling effects. The combination of spectroscopic techniques: 1D-NMR, 2D-NMR and MS revealed that ursolic acid is the major biologically active compound of O. gratissimum (Silva et al. in Molecules 13:2482–2487, 2008; Kedar et al. J Food Drug Anal 20:865–871, 2012). This study is the first report of the antisickling activity of ursolic acid isolated from O. gratissimum. The pharmaceutical relevance of findings from this study derives from the possibility of integrating O. gratissimum as an antisickling plant in the pharmacopoeia of Democratic Republic of the Congo. The identification of the active principle could enhance the standardization of antisickling recipe.Graphical Abstract

Aims: A novel β-coronavirus (2019-nCoV) has become a pandemic affecting hundreds of thousands of people worldwide. Since there is no effective treatment, the need of finding alternative methods which can help to curb this pandemic is urgent. This study aims to review the literature on the virucidal and cytotoxic properties of Aloe vera, one of the most studied plants considered as a nutraceutical in order to propose it as an alternative solution against COVID-19. Methodology: The literature review was based mainly on the COVID-19 resources that have been made freely available to the scientific community but also on the usual databases such as Pubmed and Google scholar. Results: The literature review shows that the plant has antiviral activity on several types of virus (Haemorrhagic Viral Rhobdavirus Septicaemia, Herpes simplex virus type 1, Herpes simplex virus type 2, Varicella-Zoster virus, human immunodeficiency virus, Influenza virus, poliovirus, Cytomegalovirus, Human papillomavirus) including coronavirus SARS-CoV-1. The plant is consumed orally in several forms and is safe. It is possible that  molecules of this plant that have already shown effectiveness on other viruses by some mechanisms such as interaction of virus enzyme, breakdown of the viral envelope etc. could participate in the action of the plant. Also, the presence of minerals such as Zinc, which have shown an effect on SARS-CoV-1, could be involved in the antiviral effect of Aloe vera. Conclusion: Molecular docking of the main molecules of Aloe vera with SARS-CoV-2 protease is in progress and clinical trials are necessary to confirm the activity of Aloe vera on COVID-19.

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Abstract:In accordance with statistics from the World Health Organization, nearly 80% of populations depend on traditional medicine for primary health care. In order to scientifically validate the phyto-therapeutic wealth of the Democratic Republic of the Congo, three plants were chosen namely: Afromomum alboviolaceum, Annona senegalensis and Mondia whitei. The objective of our study was to assess the antisickling, antioxidant and antibacterial activities of the ethanolic extracts and the dichloromethane fractions of these three plants. Sickle cell blood was supplied from Centre de Médecine Mixte and Anémie SS of Yolo Sud, Kinshasa. Three bacterial strains were used including Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 8739 and Pseudomonas aeroginosa ATCC 9027. The ethanolic extracts of A. alboviolaceum and A. senegalensis and dichloromethane fractions of A. alboviolaceum and M. whitei showed IC50 values < 100 µg/mL in the ABTS test. Only the dichloromethane fraction of A. senengalensis showed an IC 50 value of less than 100 µg/mL for the DPPH test. The inhibitory concentration 50 (IC 50 ) values obtained from the ABTS test are lower than those of the DPPH test. All tested extracts possess a high antisickling activity and only soluble dichloromethane extracts are active vis-à-vis Staphylococcus aureus (MIC = 31.5 µg/mL). These results constitute a scientific evidence validating the use of these three medicinal plants for the management of sickle-cell anemia in the Democratic Republic of the Congo.