COMPARATIVE EFFICACY OF PHYTOCHEMICAL ANALYSIS AND ANTIOXIDANT ACTIVITY OF METHANOLIC EXTRACT OF CALOTROPIS GIGANTEA AND CALOTROPIS PROCERA
Calotropis species is a common wasteland weed and are widely used as alternative therapeutic tool for the prevention or treatment of many diseases. This study was designed to evaluate comparative antioxidant activity, metal chelating properties and larvicidal activity of methanolic extract of two common species of Calotropis, viz. Calotropis gigantea (Linn.) R.Br. and Calotropis procera (Ait.) R.Br. The total phenolic and flavonoid content was determined and expressed in term of gallic acid equivalent and quercetin equivalent respectively. In this study, antioxidant activity was measured by radical (DPPH•) scavenging, reducing power, FRAP assay and metal chelating activity assay. The leaves of C. procera were found to have higher antioxidant potential than flower and root extract with IC50 values of 0.21μg/ml for DPPH scavenging, 0.98 mg/ ml for metal chelating. C. procera significantly more potent in scavenging free radical and antioxidant activity than C. gigantea. Extract of all parts of both species however demonstrated similar IC50 value for metal chelating activity. C. procera possess comparatively higher antioxidant activity in reducing ferric ions than C. gigantea. The leaf methanolic extract showed a concentration dependent larvicidal activity with a lowest LD50 value of 387 mg/l compared to other extracts. There was no significant difference observed in the LC50 value for larvicidal activity of all parts between C. procera and C. gigantea which indicate both species exhibits same effect against Ae. aegypti larvae. Occurrence of more total phenols and flavonoids in all parts of C. procera as compared to C. gigantea correlates to its high antioxidant activity. The observations reported in this paper could be of applied value in utilization of C. procera for different clinical purpose which showed strong antioxidant potential rather than C. gigantea