Phytochemical screening and evaluation of antioxidant activity of the stem bark of Anacardium occidentale L. and Vitellaria paradoxa C.F. Gaertn, two medicinal plants from Poro region (Northern of Côte d'Ivoire)

Anacardium occidentale and Vitellaria paradoxa are two medicinal plants traditionally used by Ivorian, particularly in the treatment of diabetes, arterial hypertension and diarrhea. The objective of this work was to evaluate the phytochemical constituents and the antioxidant activity of the stem barks of A. occidentale L. and V. paradoxa. The stem bark of both plants was used for the aqueous extraction. Major chemical groups were identified using the tube staining method followed by confirmation by thin layer chromatography (TLC). The antioxidant activity of the extracts was evaluated by DPPH method. The results of phytochemical screening of plant extracts revealed the presence of polyphenols, anthraquinones, tannins, sterols, terpenes and saponins. In addition, the evaluation of the antioxidant activity by spectrophotometry using the DPPH method showed that all extracts had significant and different antioxydant activity compared to the reference molecule (Vitamin C, IC50 = 0.80 ± 0.70 µg/mL) with respective IC50 of 0.42 ± 0.32 µg/mL for V. paradoxa and 0.87 ± 0.77 µg/mL for A. occidentale. V. paradoxa therefore has the best antioxydant activity. These results could explain the therapeutic virtues of A. occidentale and V. paradoxa in the treatment of various pathologies.