Phenolic content, antioxidant and antifungal activities of acetonic, ethanolic and petroleum ether extracts of Hypericum perforatum L.

Abstract

The objective of this study was to evaluate antifungal and antioxidant activities of Hypericum perforatum L. extracts against the growth of certain fungi. The ethanolic, acetonic and petroleum ether extracts of the plant were evaluated for phenols, flavonoids and nonflavonoids. The highest amounts of phenols (17.6 mg EPC/g dry extract) and flavonoids (16.85 mg EPC/g dry extract) were found in the acetonic extract. The highest inhibitory effect on the growth of Penicillium canescens, Fusarium oxysporum, Alternaria alternata, Aspergillus glaucus and Phialophora fastigiata by the disk diffusion method was exhibited by the ethanolic extract at the concentration of 25 mg/disk. The minimum inhibitory concentration (MIC) of the ethanolic and petroleum ether extracts was 20 mg/mL. The acetonic extract did not affect the growth of the tested fungi. Antioxidant activity was assessed by determining 1,1-diphenyl-2-picrylhydrazyl hydrate (DPPH) free radical scavenging activity. The results showed that the ethanolic extract of Hypericum perforatum L. possesses antioxidant activity. The IC50; values, defined as the concentration of the test sample leading to 50% reduction of the free radical concentration, determined for each measurement were <7.8125, 105.9, 5.99 and 12.77 μg/ml for the ethanolic extract, the acetonic extract, ascorbic acid and BHT, respectively, for DPPH free radical scavenging activity.