Abstract

Leaf extracts of Echeveria subrigida show antioxidant, antibacterial, anti-mutagenic, and α-glucosidase inhibitory activities. The inhibitory α-glucosidase is associated with the content of quercetin-3-O-glucoside and isorhametin-3-O-glucoside. The aims of this study were to analyze the effect on mice glycemia and in vitro kinetics of α-glucosidase inhibition of the hydroalcoholic extract of Echeveria subrigida standardized in the content of isorhametin-3-O-glucoside. The high-performance liquid chromatography method was validated to quantitate isorhametin-3-O-glucoside. Hydroalcoholic extract of Echeveria subrigida identity was characterized by its organoleptic, physicochemical, pharmacological and toxicological parameters. The effects on glycemia were carried out in 6 w old male Balb-C mice and using the following treatments; hydroalcoholic extract of Echeveria subrigida at 50, 100 and 200 mg/kg b.w.; positive control glibenclamide or acarbose at 10 mg/kg b.w. The inhibition kinetics of hydroalcoholic extract of Echeveria subrigida was determined by the Lineweaver-Burk plots. Hydroalcoholic extract of Echeveria subrigida had 4.87±0.14 mg isorhametin-3-O-glucoside/g, complied with the World Health Organization parameters for standardized extracts and induced a mixed inhibition on α-glucosidase. Hydroalcoholic extract of Echeveria subrigida (200 mg/kg b.w) and glibenclamide treatments showed similar percent hypoglycemia, 49.1 % and 52 %, respectively. The anti-hyperglycemic assay showed that similar percent reductions in glucose-levels were found in the treatments with hydroalcoholic extract of Echeveria subrigida (100 mg/kg, 29.32 %; 200 mg/kg, 28.99 %) and acarbose (10 mg/kg, 19.87 %). The standardized hydroalcoholic extract of Echeveria subrigida showed hypoglycemic and anti-hyperglycemic activities, stability, and innocuity, suggesting its potential to prevent/treat diabetes mellitus.