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

Cistus genus (Cistaceae) comprises several medicinal plants used in traditional medicines to treat several pathological conditions including hyperglycemia. These include Cistus salviifolius L. (CS) and Cistus monspeliensis L. (CM), still not fully explored as a source of metabolites with therapeutic potential for human diseases. In this study, the antioxidant α-amylase and α-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. The α-amylase and α-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 towards α-glucosidase (IC(50): 0.95 ± 0.14 to 14.58 ± 1.26 μg/mL) and significant inhibitory potential against α-amylase (IC(50): 217.10 ± 0.15 to 886.10 ± 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.