Phytochemical screening, DPPH scavenging and antimicrobial activities of leaves of Eucalyptus camaldulensis, Cassia mimosoides and Vepris heterophylla from Northern Cameroon

Abstract

The aim of this study was to evaluate phytochemical constituents, antioxidant and antimicrobial activities of hexane, acetone and methanol extracts of three medicinal plants (Eucalyptus camaldulensis (Myrtaceae), Cassia mimosoides (Fabaceae) and Vepris heterophylla (Rutaceae)) traditionally used in the treatment of microbial diseases and food preservations. Qualitative phytochemical screening of the large family of compounds followed by quantitative evaluation of phenolic compounds and flavonoids was realised. The antioxidant activity was evaluated by the scavenging of DPPH radicals and the antimicrobial activity by agar well diffusion method. The results showed presence of phenolics, flavonoids, coumarins, alkaloids, triterpenes and steroids in the various extracts. The total amount of phenolic compounds ranges from 6098.76±30, 04 to 626.34±16, 13 mg of GAE and the amount of flavonoids from 57.95±1, 23 and 27.50±8,11 mg QE. The largest amount of phenolics and flavonoids was found in the acetone extract of C. mimosoides and the lowest in the methanol extract of V. heterophylla. The highest inhibition percentage of DPPH was obtained with the acetone extract of C. mimosoides which was 80% and the lowest was the methanol extract of V. heterophylla. The hexan extract of selected plants showed the higher inhibition diameter range from 12 to 15 mm with the maximum obtained with extract of E. camaldulensis.