Total phenolic content, flavonoid content and in vitro antioxidant activities of Cressa cretica Linn

摘要

The total phenolic content (TPC) and total flavonoid content (TFC) of ethylacetate fraction (Fr-Et) and methanol fraction (Fr-Me) of an Indian ayurvedic plant Cressa cretica Linn were measured using Folin–Ciocalteau and aluminum chloride colorimetric methods, respectively. The in vitro antioxidant activities were also investigated by using in vitro antioxidant models including 2,2´-azinobis–(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+), 1,1- diphenyl-2-picrylhydrazyl (DPPH), nitric oxide (NO), hydroxyl radical (OH?￡￥), super oxide (SO) and reducing power (Fe3+ to Fe2+ transformation) assay. The TPC were 7.081±1.033 and 12.833±0.24 mg gallic acid equivalents (GAE)/g extract, while TFC were 6.664±0.985, 11.979±1.049μg quercetin equivalents (QRT)/g extract sample for (Fr-Me and (Fr-Et), respectively. Analysis of the free radical scavenging activities of the fractions revealed a concentration-dependent antiradical activity resulting from reduction of ABTS+, DPPH, NO, OH?￡￥ and SO radicals to non-radical form. The scavenging activity of ascorbic acid, a known antioxidant used as positive control, was however higher and scavenging potential was in the order: ascorbic acid Fr-Et Fr-Me. The reducing power of ascorbic acid, Fr-Et, Fr-Me increased gradually with increasing concentration. The order of the reduction potential was ascorbic acid Fr-Et Fr-Me. These results obtained in the present study indicate that C.cretica fractions can be a potential source of natural antioxidant with strong antiradical capacity.