Worldwide people suffer from metabolic syndrome and its complications. For these conditions, functional foods are
becoming more important. We aimed to determine the amounts of corosolic acid in Lagerstroemia species and their α-
glucosidase inhibitory potency. In addition, we developed a new source of corosolic acid using the plant tissue culture technique.
The HPLC-UV method was reliable and applicable for corosolic acid determination of the Lagerstroemia species. Although the
corosolic acid standardized extract is usually prepared using L. speciosa, our results revealed that L. macrocarpa and L. loudonii
contained much higher amounts of corosolic acid. In addition, the established callus culture of L. speciosa produced corosolic
acid with higher content than their parental L. speciosa mature leaves. The corosolic contents in these samples were also in
agreement with α-glucosidase inhibitory activity. Therefore, this method is worthy of antidiabetic standardization of Lagerstroemia
derived materials.