Phytochemical screening and antioxidant activity of methanolic extracts of 53 antimalarial plants from Bagira in Eastern DR Congo

A previous study inventoried 53 plants used in traditional medicine in Bagira in Eastern Democratic Republic of Congo (DRC) in the management of malaria. During malaria disease, oxidative stress is responsible for the worsening of the patient's condition. This study aims to identify phytochemical groups and to evaluate antioxidant activity of 53 plants used in traditional medicine in Bagira to treat malaria. The phytochemical screening was carried out by conventional reactions in solution and antioxidant activity used in vitro method with 1,1-diphenyl-2- picrylhydrazyl radical (DPPH). Chemical screening has identified secondary metabolites with both antimalarial and antioxidant potential such as coumarins, steroids, saponins, tannins and terpenoids in more than 70% of plants. Antioxidant screening revealed for the first-time antioxidant activity of 18 plants, among which Dalbergia katangensis, Dialium angolense and Solanecio cydoniifolius with IC₅₀ ≤ 1.6 µg / mL having the highest activities. This study shows that among plants used as antimalarial in Bagira several possess antioxidant power and contain many of groups presumed to be both antioxidant and antimalarial. This suggests that further studies continue to isolate compounds responsible for the proven activity.