A flavone derivative from Andrographis echioides leaf extract positively alters the molecular targets of insulin signaling pathway

Insulin resistance and obesity go hand-in-hand while considering the pathophysiology of type 2 diabetes. The mechanism of obesity-related insulin resistance includes a series of molecular markers such as insulin receptor substrate, protein kinase, glucose transporter, etc., that act as primary targets for various antidiabetic drugs. However, the undesired side effects of these drugs have steered research toward safer and more effective alternatives. This study involves the bioactivity-guided isolation of phytocompounds from Andrographis echioides and studying its effect on the above-mentioned molecular markers. The bioactive compounds were first isolated by column chromatography and tested for their α-amylase inhibition potential. The compound with better inhibition ability was then characterized using FTIR, MS, ¹H, and ¹³C NMR techniques. Then, the compound was evaluated for its glucose uptake enhancing ability and cytotoxicity against 3T3 L1 and L6 cell lines. Furthermore, the mechanism of action of the compound was studied on molecular targets such as PPARγ, IRS, IRβ, GLUT4, and Tyr-PI3K. As a result, 5-hydroxy- 2-(4‑methoxy-3-((E)-3-methylbut-1-enyl)-5-(3- methylbut-3-enyl)phenyl)chroman-4-one, was isolated and found to be a significant inhibitor of α-amylase enzyme (IC₅₀ value of 14.52 µg/ml) and PPARγ (IC₅₀ value of 3.357 µg/ml). In addition, it was a strong enhancer of glucose uptake in both 3T3 L1 (48.82 ±2.74%) and L6 (63.83 ± 1.54%) cell lines. The mechanism of action was altering the insulin-signaling pathway by upregulating the molecular proteins involved in the etiology of type 2 diabetes. In conclusion, the compound isolated from the leaves of Andrographis echioides possesses a significant regulatory effect on glucose uptake and other markers of the insulin-signaling pathway.