Antioxidant Activity and Inhibitory Potential ofCistus salviifolius(L.) andCistus monspeliensis(L.) Aerial Parts Extracts against Key Enzymes Linked to Hyperglycemia

Abstract
Cistusgenus (Cistaceae) comprises several medicinal plants used in traditional medicines to treat several pathological conditions including hyperglycemia. These includeCistus salviifoliusL.(CS) andCistus monspeliensisL.(CM), still not fully explored as a source of metabolites with therapeutic potential for human diseases. In this study, the antioxidantα-amylase andα-glucosidase enzyme inhibitory effects of aqueous and hydromethanolic extracts from the aerial parts of Moroccan CS and CM were investigated. Antioxidant activity has been assessed using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radicals and ferric reducing/antioxidant power (FRAP) methods. Theα-amylase andα-glucosidase inhibitory activity has been assessed using an in vitro model. Moreover, mineral and phenolic contents of CS and CM were analyzed. The extracts of both species exhibited potent antioxidant activity in all used systems and possess strong inhibitory effect towardsα-glucosidase (IC50:0.95±0.14to14.58±1.26 μg/mL) and significant inhibitory potential againstα-amylase (IC50:217.10±0.15to886.10±0.10 μg/mL). Furthermore, the result showed high levels of phenolic content and unexpectedly some higher levels of mineral content in CS. The results suggest that the phenolic rich extracts of CS and CM may have a therapeutic potential against diseases associated with oxidative stress and may be useful in the management of hyperglycemia in diabetic patients.