Comparative Evaluation of Phytochemical Constituents and Antioxidant Capacity of Some Ethnomedicinal Plants Used In Western Nigeria

Abstract

This study investigated and compared the phytochemical constituents and antioxidant property of Phyllanthus amarus, Vernonia amygdalina, Carica papaya and Jatropha curcus which are commonly used in traditional medicine. This was achieved by evaluating the quantitative and qualitative presence of the phytochemicals and also determining the free radical scavenging potentials of the plant leaf extracts. The results of this study revealed that the leaf extracts of the test plants contain some proportions of important phytochemicals which includes alkaloids, tannins, saponins, flavonoids, phenols, steroids, glycosides, cardiac glycoside. In furtherance, it showed that the selected plants vary significantly in their percentage ferric reducing antioxidant potentials (FRAP) expressed in gallic acid equivalents(GAE) ranging from 63.624 ± 0.14 to 165.076 ± 0.24 mg/100g and all the sample extracts exhibited moderate to significant inhibition of 1,1 diphenyl-2-picryl-hydrazyl (DPPH) activity expressed in trolox equivalent (TAEC) ranging from 1.306±0.20 to 38.943± 0.11/100g. Considering all the parameters assayed, antioxidants capacities were significant in the sequence of P.amarus, V. amygdalina , J. curcas and C. Papaya. This current study shows that the test plants contain useful phytochemicals which makes them employable in traditional medical practices. However more work needs to be done to determine which of these phyto-constituents exert the greatest potency in therapeutic and antioxidant activities.