PHYTOCHEMICAL STUDIES AND ANTIOXIDANT ACTIVITY OF A HEMIPARASITIC PLANT (TAPINANTHUS BANGWENSIS ENGL. & KRAUSE, LORANTHACEAE) AND ITS HOST (COMBRETUM MICRANTHUM G. DON, COMBRETACEAE)

Tapinanthus bangwensis is a hemiparasitic plant of the Senegalese flora found in several host plant species such as Combretum micranthum. These two species are used in traditional medicine against several diseases. The aim of this study was to conduct a comparative study between the parasitic plant (Tapinanthus bangwensis) and its host (Combretum micranthum) with regard to their chemical composition and antioxidant activity. Phytochemical screening of the two plants leafy stems were carried out by coloring and/or precipitation reactions. The total polyphenol contents were evaluated by the Folin-Ciocalteu reagent and the flavonoid content by a method using aluminium chloride (AlCl₃) and sodium nitrite (NaNO2). As for the antioxidant activity, it was evaluated by DPPH and FRAP methods. The same chemical groups were identified in both plants. However, T. bangwensis was richer in total polyphenols than C. micranthum with respective contents of 145.85±6 and 120.08±2.62mgEAG/g of dry extract. Thus, T. bangwensis extract showed more antioxidant activity than C. micranthum extract with respective IC₅₀ of 3.49±0.06 µg/ml and 6.32±0.05 µg/ml. The parasitic plant has a better antioxidant activity possibly due to its higher concentration in secondary metabolites, in particular, polyphenols.