Assessment on antioxidant capacity and tyrosinase inhibition activity of Pistacia weinmannifolia extracts

Pistacia weinmannifolia is a plant which has multiple function of greening, medicinal, bacteriostasis and cosmetology. In this study, the concentration of total polyphenols and flavones, the antioxidant capacity in vitro and tyrosinase inhibition activity of the ingredients extracted from Pistacia weinmannifolia were determined. The results showed that the concentration of total polyphenols and flavones in water extract were 42.67 mg/g (DW) and 18.69 mg/g (DW), respectively, which were significantly higher than that of ethanol extract. In vitro antioxidant activity tests showed that IC50 on scavenging DPPH, ABTS⁺ and hydroxyl radicals of water extract were 7.95, 11.71, 3.26 mg/mL, respectively. Meanwhile, the antioxidant activity of water extract was higher than that of ethanol extract. Enzymatic kinetics experiments showed that water extract of Pistacia weinmannifolia had a significant inhibition on tyrosinase activity, and the inhibition ability increased significantly by the increase of extract concentration. When the concentration reaching to 0.2 mg/mL, the inhibition rate reached to 80%. Furthermore, it was found that there were obviously negative correlation between the concentration of total polyphenols and flavones with antioxidant capacity and tyrosinase inhibition activity, which leads to the conclusion that Pistacia weinmannifolia contains affluent polyphenols and flavones, which might effectively scavenge free radicals and inhibit the activity of tyrosinase.