Study of antidiabetic potential and role of corosolic acid in some antidiabetic plants of Himachal Pradesh

Abstract

The study aimed to detect corosolic acid in traditionally utilized antidiabetic plants in Himachal Pradesh, exploring regions within the Upper Himalayas, Lower Himalayas, and Shivalik range. Surveys were conducted, engaging local vaids, shepherds, and healers to understand the historical significance of antidiabetic plant material. The diverse flora and climate of Himachal Pradesh were chosen for the study, despite corosolic acid typically being associated with subtropical plants. Field surveys identified 14 plants for corosolic acid evaluation, with only 6 showing its presence through HPLC analysis. Unexplored plants in colder regions, such as Pyrus malus (apple), were included, revealing corosolic acid synthesis in apple peel. Ursolic acid, a precursor to corosolic acid, guided plant selection based on literature. Selected corosolic acid-synthesizing plants underwent in vitro antioxidant and antidiabetic tests. Ziziphus jujuba exhibited the highest corosolic acid concentration (56.8 µg/20 mg dw), surpassing Diospyros kaki and Melaleuca genistifolia. In vitro assays highlighted Ziziphus jujuba superior antioxidant potential, surpassing standard ascorbic acid. The plant also demonstrated notable alpha-amylase inhibition, outperforming standard acarbose. In vivo studies focused on Ziziphus jujuba, showing its highest corosolic acid content and promising in vitro results. Diabetic rats treated with Ziziphus jujuba leaf extract (100 mg/kg) exhibited improved body weight and normalized blood sugar levels compared to glibenclamide. Histopathology revealed enhanced islet cell regeneration, reduced necrosis, and improved pancreas structure, surpassing the effects of glibenclamide. The study concluded that using plant extracts for diabetes treatment is more advantageous than synthetic medications with potential side effects. newline