Phytochemical Composition and Acute Hypoglycemic Effect of Jefea lantanifolia (S. Schauer) Strother in Rats

Jefea lantanifolia (S. Schauer) Strother is traditionally used in Hidalgo, Mexico, to manage type 2 diabetes (T2D). The aerial parts are prepared as an infusion and consumed throughout the day. This study conducted a 2 h acute experiment under both fasting and postprandial conditions to evaluate the effects of the aqueous infusion (AE), the ethanol-water extract (EWE), and their isolated constituents in hyperglycemic rats. Structures were established using conventional spectroscopic methods. The absolute configuration was determined by optical rotation and calculated electronic circular dichroism (ECD) methods. Phytochemical analysis led to the isolation of six compounds: luteolin (1); 2β-hydroxy-dimerostemma brasiolide-1-O-(3-hydroxymethacrylate) (2); homoplantaginin (3); cynarin (4); luteolin-7-O-glucoside (5); and nepitrin (6). The extract was deemed safe at a dose of 2 g/kg b. w. in acute toxicity assays. In vivo experiments showed significant reductions in blood glucose levels during fasting, with compounds 2 and 3 achieving reductions of 42% and 40%, respectively, compared to 51% with glibenclamide. Postprandially, all treatments demonstrated effective glucose-lowering activity, particularly compound 3 and the EWE. These findings support the traditional use of J. lantanifolia and highlight its phytochemicals as promising candidates for further pharmacological investigation. Long-term studies and high-dose evaluations are warranted to validate therapeutic potential and establish safety profiles.