Preliminary research regarding the cytotoxicity and antioxidant activity of arbutus unedo L. Leaves

Abstract

The aim of the study was the selection of optimum extraction procedure of Arbutus unedo L. leaves in order to obtain dry extracts with high content of polyphenols and arbutin. The antioxidant activity, cytotoxicity and genotoxicity of the extracts were also evaluated. Two types of extracts were obtained using refluxation and sonication, respectively. The total polyphenolic compounds were assessed spectrophotometrically with the Folin-Ciocâlteu method. Arbutin was detected and quantified by HPLC-DAD. The extracts’ antioxidant activity was investigated using ferric reducing activity and 2,2-diphenyl-1-picrylhydrazyl (DPPH) methods. The results were expressed as antioxidant activity index (AAI) for DPPH method and as EC50 (μg/mL) for both methods. Cytotoxicity/genotoxicity was verified by the Triticum (vegetal cell) and Artemia tests (animal cell). The highest content of arbutin, polyphenolic compounds and the highest DPPH free radical scavenging activity were found for the extract obtained by refluxation (32.84 g% polyphenols expressed as tannic acid, 1.92 g% arbutin, AAI = 6.45, EC50 = 43.78 mg/mL). The extract containing the highest concentration in polyphenols is a very strong antioxidant as stated by antioxidant index. Despite the genotoxic effect of both extracts at high concentrations, low concentrations showed no cytotoxicity either on the plant cell or on the animal cell.