Andrographis paniculata improves glucose regulation by enhancing insulin sensitivity and upregulating GLUT 4 expression in Wistar rats
W A Saka, Olubunmi Simeon Oyekunle, Tunmise Maryanne Akhigbe, O. O. Oladipo, M.B. Ajayi, Adedayo T. Adekola, Ayomide Isaac Omole, Roland Eghoghosoa Akhigbe
Abstract
Context Although the hypoglycaemic effect of Andrographis paniculata (Burm.f.) Nees [Acanthaceae] has been documented, reports on its effect in an apparently healthy state are limited. Objective This study investigated whether or not A. paniculata exerts hypoglycaemic effect in a non-diabetic state. It also explored the impact of A. paniculata on glycolytic enzymes and GLUT 4 protein expression, as a possible mode of action. Methods Twenty male Wistar rats were randomly assigned into two groups ( n = 10 rats/group). The control rats were vehicle-treated (0.5 ml of distilled water), while the A. paniculata -treated rats had 500 mg/kg of A. paniculata per os once daily for 35 days. Results A. paniculata treatment led to improved insulin sensitivity evidenced by increased HOMA-β (88.08 ± 2.13 vs. 120.80 ± 1.52, p < 0.0001), HOMA-S (283.60 ± 8.82 vs. 300.50 ± 9.30, p = 0.0189), and reduced TyG index (4.22 ± 0.04 vs. 3.95 ± 0.07, p < 0.0002) and HOMA-IR (0.32 ± 0.01 vs. 0.25 ± 0.01, p < 0.0001) when compared with the control. It also improved glucose regulation as depicted by reduced fasting blood glucose (3.77 ± 0.10 vs. 3.24 ± 0.11, p < 0.0001) and glycated hemoglobin (HbA1c; 7.69 ± 1.15 vs. 5.95 ± 0.82, p = 0.0245), and atherogenic dyslipidaemia, including AIP (−0.12 ± 0.03 vs. −0.26 ± 0.03, p < 0.0001) and CRI-I (2.70 ± 0.29 vs. 1.84 ± 0.27, p < 0.0001). These findings were accompanied by enhanced hepatic and muscular redox state, increased activities of glycolytic enzymes, upregulated GLUT 4 (0.80 ± 0.27 vs. 6.20 ± 0.84, p < 0.0001), and increased circulating nitric oxide (5.45 ± 0.24 vs. 6.79 ± 0.33, p = 0.0002). Conclusion A. paniculata exerts positive effect on glucose metabolism and utilization by improving insulin sensitivity and upregulating the activities of glycolytic enzymes and GLUT 4 protein expression. This implies that A. paniculata may be beneficial in preventing insulin resistance and incident diabetes. Nonetheless, it should be used with caution to prevent hypoglycaemia in a non-diabetic state.