COMPARATIVE EVALUATION OF THE ANTIRADICAL ACTIVITY OFMEDLAR AND QUINCE LEAF EXTRACTS BY THE DPPH METHOD

Abstract

The present study evaluated the antiradical activity of alcoholic and aqueous extracts prepared from medlar and quince leaves using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assay. Leaf mixtures were investigated at 1:1, 3:1 and 1:3 ratios. For each preparation, 1 g of plant material was extracted with 25 mL of either water or 96% ethanol for 20 min in an ultrasonic bath. The extracts were filtered through a 0.45 μm syringe filter and diluted tenfold before analysis. Absorbance was measured spectrophotometrically at 517 nm at 5-min intervals for 30 min. Antiradical activity (ARF%) was calculated from the decrease in DPPH absorbance, and IC50 values were estimated from linear trend equations based on the 30-min ARF values. At 100 μL extract volume, the 30-min ARF values were 75.59%, 77.44% and 43.46% for the 1:1, 3:1 and 1:3 alcoholic extracts, respectively, while the corresponding aqueous extracts produced 64.78%, 69.60% and 66.33%. Estimated IC50 values ranged from 62.16 to 63.06 μL for the alcoholic preparations and from 62.98 to 71.87 μL for the aqueous preparations. The findings demonstrate measurable DPPH-scavenging activity in all investigated extracts and show that extraction solvent and mixture ratio influence the observed response.