title: Evaluation of α-Glucosidase Inhibitory Effect of 50% Ethanolic Standardized Extract of Orthosiphon stamineus Benth in Normal and Streptozotocin-Induced Diabetic Rats.
abstract: In the present study, a 50% ethanolic extract of Orthosiphon stamineus was tested for its α-glucosidase inhibitory activity. In vivo assays of the extract (containing 1.02%, 3.76%, and 3.03% of 3'hydroxy-5,6,7,4'-tetramethoxyflavone, sinensetin, and eupatorin, resp.) showed that it possessed an inhibitory activity against α-glucosidase in normal rats loaded with starch and sucrose. The results showed that 1000 mg/kg of the 50% ethanolic extract of O. stamineus significantly (P < 0.05) decreased the plasma glucose levels of the experimental animals in a manner resembling the effect of acarbose. In streptozotocin-induced diabetic rats, only the group treated with 1000 mg/kg of the extract showed significantly (P < 0.05) lower plasma glucose levels after starch loading. Hence, α-glucosidase inhibition might be one of the mechanisms by which O. stamineus extract exerts its antidiabetic effect. Furthermore, our findings indicated that the 50% ethanolic extract of O. stamineus can be considered as a potential agent for the management of diabetes mellitus.
authors.affiliation: School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia.
authors.forename: Elsnoussi Ali
authors.initials: EA
authors.lastname: Mohamed
authors.affiliation: School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia.
authors.forename: Mariam
authors.initials: M
authors.lastname: Ahmad
authors.affiliation: School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia.
authors.forename: Lee Fung
authors.initials: LF
authors.lastname: Ang
authors.affiliation: School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia.
authors.forename: Mohd Zaini
authors.initials: MZ
authors.lastname: Asmawi
authors.affiliation: School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia.
authors.forename: Mun Fei
authors.initials: MF
authors.lastname: Yam