Momordica balsamina improves glucose handling in a diet-induced prediabetic rat model.

Prolonged exposure to high energy diets has been implicated in the development of pre-diabetes, a long-lasting condition that precedes type 2 diabetes mellitus (T2DM). A combination of pharmacological treatment and dietary interventions are recommended to prevent the progression of pre-diabetes to T2DM. However, poor patient compliance leads to negligence of the dietary intervention and thus reduced drug efficiency. Momordica balsamina (MB) has been reported to possess anti-diabetic effects in type 1 diabetic rats. However, the effects of this medicinal plant in conjunction with dietary intervention on pre-diabetes have not yet been established. Consequently, this study sought to evaluate the effects of MB on glucose homeostasis in a diet-induced pre-diabetes rat model in the presence and absence of dietary intervention. Pre-diabetes was induced on male Sprague Dawley rats by a high fat high carbohydrate (HFHC) diet for a period of 20 weeks. Pre-diabetic male Sprague Dawley rats were treated with MB (250 mg/kg p.o.) in both the presence and absence of dietary intervention once a day every third day for a period of 12 weeks. The administration of MB with and without dietary intervention resulted in significantly improved glucose homeostasis through reduced caloric intake, body weights, with reduced plasma ghrelin concentration and glycated hemoglobin by comparison to the pre-diabetic control. MB administration also improved insulin sensitivity as evidenced by the expression of glucose transporter 4 (GLUT 4) and glycogen synthase on the prediabetic treated animals. These results suggest that MB has the potential to be used to manage pre-diabetes and prevent the progression to overt type 2 diabetes as it demonstrated the ability to restore glucose homeostasis even in the absence of dietary and lifestyle intervention.

Bredemolic acid restores glucose utilization and attenuates oxidative stress in palmitic acid-induced insulin-resistant C2C12 cells.

Objective. Due to insulin resistance and oxidative stress that are associated with type 2 diabetes mellitus (T2DM), T2DM has become a prevalent metabolic disorder that presents various side effects. However, alternative antidiabetic treatment has commonly been used in treating diabetes mellitus in diabetic patients. In our previous studies, bredemolic acid has been reported as an antidiabetic agent that improves glucose uptake, ameliorates insulin resistance, and oxidative stress in the liver, heart, kidney, and skeletal muscle of prediabetic rats. However, these effects have not been validated in vitro. Therefore, this study was aimed to investigate the effects of bredemolic acid on insulin-mediated glucose utilization, lipid peroxidation, and the total antioxidant capacity (TOAC) in palmitic acid-induced insulin-resistant C2C12 skeletal muscle cells in vitro. Methods. Insulin resistance was induced in the skeletal muscle cells after 4 h of exposure to palmitic acid (0.5 mmol/l). Different cell groups were incubated in culture media DMEM supplemented with fetal calf serum (10%), penicillin/streptomycin (1%), and L-glutamine (1%) and then treated with either insulin (4 µg/ml) or bredemolic acid (12.5 mmol/l) or with both. Thereafter, the cells were seeded in 24- or 96-well plates for determination of the cell viability, glucose utilization, glycogen formation, and antioxidant capacity. Results. The results showed that bredemolic acid significantly improved TOAC and promoted glucose utilization via attenuation of lipid peroxidation and increased glycogen formation in the insulin-resistant cells, respectively. Conclusion. This study showed that bredemolic acid restored the insulin resistance through improved glucose utilization, glycogen formation, and TOAC in the skeletal muscle cells.