High-performance liquid chromatography for analysis of corosolic acid in Lagerstroemia species and their hypoglycemic activities

Metabolic syndromes are one of the global health problems. Functional foods with α-glucosidase inhibitory properties is a complementary choice for diabetes patients. Lagerstroemia speciosa has been applied traditionally for an antihyperglycemic purpose in traditional medicines. Corosolic acid is considered as bioactive constituents for glucose lowering effect of L. peciosa [1], [2]. In the present study, we aimed to determine corosolic acid in Lagerstroemia species using the developed HPLC-UV method and their α-glucosidase inhibitory potency. In addition, we developed the new source of corosolic acid using the plant tissue culture technique. According to analytical performance including precision, sensitivity, and accuracy, the developed HPLC-UV method is reliable and applicable for corosolic acid determination of the Lagerstroemia species. The compound exists in varied amount in different Lagerstroemia species (0.21 ± 0.01 to 3.77 ± 0.17 mg/g dry wt.). The mature leaves composed the highest content. Although standardized extract usually prepared using L. speciosa, our results revealed that L. macrocarpa and L. loudonii contained much higher amounts of corosolic acid. In addition, the callus culture of L. speciosa also produced high content of corosolic acid. The corosolic contents of investigated Lagerstroemia species with α-glucosidase inhibitory activity. Therefore, this method is worth for antidiabetic standardization of Lagerstroemia derived materials.

• References

• 1 Klein G, Kim J, Himmeldirk K, Cao Y, Chen X. Antidiabetes and anti-obesity activity of Lagerstroemia speciosa . Evid Based Complement Alternat Med 2007; 4 , 401-407
• 2 Miura T, Takagi S, Ishida T. Management of diabetes and its complications with banaba (Lagerstroemia speciosa L.) and corosolic acid. Evid Based Complement Alternat Med 2012; 871495-871495