Estimation of antioxidant activity and total phenolics among natural populations of Caper (Capparis spinosa) leaves collected from cold arid desert of trans-Himalayas

Abstract

Antioxidant activity (%) of Capparis spinosa leaves collected from nine different sites from three valleys in trans-Himalayan region of Ladakh (India) were measured using DPPH, ABTS and FRAP assay along with its polyphenol content. Maximum DPPH and ABTS radical scavenging activity was observed from leaves samples collected from Skuru and least from Tirchey site. FRAP assay revealed that Skuru site possess maximum antioxidant content as compared to the samples collected from any other location. IC50 of ABTS were quite reasonably correlated with FRAP assay (R2=0.517) while, DPPH IC50 was poorly correlated with both ABTS (R2=0.100) and FRAP assay (R2=0.223). The highest and lowest phenolic and flavonoid content was recorded in Skuru and Tirchey sites respectively. Total phenolics (27.62-21.42 mg GAE/g DW) and flavonoid content (6.96-2.69 mg quercetin equivalent/g DW) were found reasonably correlated with IC50 of ABTS (R2=0.741 and 0.703, respectively) and FRAP (R2=0.605 and 0.649, respectively) but poorly correlated with DPPH IC50 (R2=0.303 and 0.408, respectively). Results of present study confirmed the antioxidant potential of C. spinosa leaves collected from different locations of trans-Himalayas, whose phyto-chemistry and phyto-pharmacology should be investigated further in order to detect possible phyto-therapeutic uses where free radicals are implicated.