PHYTOCHEMICAL CHARACTERIZATION AND ANTIOXIDANT EVALUATION OF HYDROETHANOLIC EXTRACTS OF BOSCIA FOETIDA LEAVES AND ROOT

Salustiano Zavale¹, François Munyemana², Atifa Sulemane²

Mozambique is still among countries whose 60% of population rely largely in medicinal plants for the treatment of diseases and ailments. Therefore, a detailed study of these plants can promote a safe use. In this sense, this work was aimed in conducting phytochemical analyzes and evaluation of the antioxidant activity of the extracts of the leaves and root barks of Boscia foetida Schinz. The qualitative phytochemical analysis was performed using classic methods (colorimetric and precipitation), thin layer chromatography and gas chromatography coupled to mass spectrometry. Quantification of total phenols, total flavonoids and condensed tannins was conducted using the spectrophotometric method. Antioxidant activity was determined using DPPH radical scavenging, phosphomolybdene complex reduction and ferric reducing antioxidant power methods. Preliminary phytochemical tests and thin layer chromatography revealed the presence of alkaloids, phenols, flavonoids, coumarins, condensed tannins, phytosteroids, triterpenoids, saponins and cardiac glucosides. Gas chromatography coupled to mass spectrometry analysis allowed the identification of 29 compounds, which included alkanes, fatty acids and esters of fatty acids, isothiocyanates, nitriles and amides. The contents of phenols, flavonoids and condensed tannins (90.15 ± 0.40mgGAE/100g powder, 837.96 ± 1.36mgQE/100g DW and 225.60 ± 0.56mgCyaE/100g DW, respectively) observed in leaves were higher than those observed in root barks (49.21 ± 0.46mgGAE/100g DW, 143.51 ± 0.79 mgQE/100g DW and 117.47 ± 6.75mgCyaE/100g DW, respectively). Higher DPPH radical scavenging power and reduction of the phosphomolybdene complex was exhibited by the chloroform leaf fraction and the higher ferric reduction antioxidant power was exhibited by butanolic leaf fraction. The results suggest that Boscia foetida Schinz is an important source of phytochemicals with interesting pharmacological properties, which may explain its use in traditional medicine.

Keywords: antioxidant, phytochemical, phenols, flavonoids and tannins.