Evaluation of the phytochemical composition, antimicrobial and anti-radical activities of Mitracarpus scaber (Rubiaceae)

Mitracarpus scaber is a medicinal plant used in traditional practices for the treatment of dermatoses and liver diseases. The objective of this study was to quantify the content of phenolic compounds and to evaluate the anti-radical and antimicrobial activities of four types of its total extracts on ten microbial strains. The Folin-Ciocalteu method was used to determine total phenol content, condensed tannin content by the Butanol-HCl method and anti-radical activity by reduction of phosphomolybdate. The micro-dilution technique coupled with spreading in an agar medium made it possible to evaluate the antimicrobial activity. The results obtained showed that the total phenol content varies according to the nature of the extracts and ranges from 36.75±1.62 mg / g to 14.63±0.44 mg / g of extract. The contents of condensed tannins ranged from 41.83%±0.03 mg CE / g to 0.39%±0.14 mg CE/g. The anti-free radical activity was between 0.48±0.06 mg AAE / g and 0.21±0.00 mg AAE/g. The antimicrobial activity gave MIC of 6.25 to 50 mg / ml. The hydroalcoholic extract showed lower MIC and would therefore be best suited for the treatment of microbial diseases. Key words: Mitracarpus scaber, antimicrobial activity, antiradical activiy, phenols.