Abstract

PHYTOCHEMICAL SCREENING AND ANTIOXIDANT ACTIVITY OF LEAF EXTRACTS OF GYMNEMA SYLVESTRE R. Br. FROM DIFFERENT REGIONS OF TAMIL NADU

Janarthanam Balasundaram and Sumathi Ethiraj*

Abstract

Objective: The present study was performed to evaluate the phytochemical screening, total phenol, total flavonoid, total terpenoid content and antioxidant activity of leaf extracts of Gymnema sylvestre collected from ten different regions of Tamil Nadu. Materials and Methods: Phytochemical screening of various extracts such as aqueous and ethanol leaf extracts of Gymnema sylvestre, quantitative estimation of total phenol, total flavonoid and total terpenoid contents were carried out according to the standard methods. The leaf extracts were evaluated for their antioxidant activities by DPPH (1,1-diphenyl-2- picrylhydrazyl) free radical scavenging activity. Results: The phytochemical screening of aqueous and ethanolic leaf extracts of Gymnema sylvestre revealed the presence of tannins, saponins, phenols, flavonoids, glycosides, terpenoids and alkaloids. Among ten different accessions of G. sylvestre with their aqueous and ethanolic leaf extracts, the ethanolic leaf extracts of G. sylvestre (courtallam accession) were recorded to be rich in secondary metabolites such as tannins, saponins, flavonoids, phenols, glycosides, terpenoids and alkaloids followed by other accessions. The total phenol, flavonoid and terpenoid content were found to be maximum in the leaf extracts of G. sylvestre (courtallam accession) which recorded 27.14 ± 0.21 mg gallic acid equivalents (GAE)/g, 33.62 ± 0.25 mg quercetin Equivalent (QE)/g and 63.82 ± 0.35 mg /g respectively. Among the ten accessions with two different solvents used, maximum percentage of antioxidant activity was found in ethanolic leaf extract of Gymnema sylvestre from courtallam accession (91.34 ± 1.05) followed by leaf extract of Gymnema sylvestre from salem accession (85.08 ± 0.30) and tiruvannamalai accession (81.13 ± 0.25) respectively. Conclusion: The results obtained from the current study revealed that the ethanolic extracts from dry powdered leaf of Gymnema sylvestre (courtallam accession) had superior level of antioxidant activity. The powerful antioxidant effect is attributed to the greater amount of phenols and flavonoids compound in the leaf extracts of Gymnema sylvestre.

Keywords: Gymnema sylvestre, Antioxidant activity, DPPH, Phytochemical screening, Total phenol, Total flavonoid, Total terpenoid.