Upregulation of MC4R and PPAR-α expression mediates the anti-obesity activity of Moringa oleifera Lam. in high-fat diet-induced obesity in rats.

various extracts of Moringa oleifera Lam. leaves, were reported to possess antiobesity effect in experimental animals models, yet its active doses and mechanism of action are still unclear.

The metabolic profiling of 70% ethanol extract of M. oleifera (MO) leaves was performed using HPLC-MS/MS analysis. The antiobesity activity of MO was tested in high fat diet induced obesity in rats at 200 and 400 mg/kg body weight orally for 1 month. Total cholesterol (TC), high density lipoproteins (HDL-C), low density lipoprotein-cholesterol (LDL-C), triglycerides (TGs), insulin resistance, insulin sensitivity, and adipose tissue index were monitored. In addition, fatty acid synthase (FAS) and HMG-CoA reductase mRNA from liver tissue, Peroxisome Proliferator-Activated Receptor alpha (PPARα) and Melanocortin-4 receptor (MC4R) RNA from adipose tissue were quantified using qRT-PCR. MO hard gelatin capsules (400 mg/capsule) were formulated and standardized using HPLC-RP analysis and tested on fifteen female participants, aged 45-55 with a BMI of 29-34 kg/m².

Thirteen metabolites were tentatively identified using HPLC-MS/MS analysis including flavonols, flavones and a phenolic acid. MO 400 showed a prominent effect on reducing the rats' final weights, % weight increase and adiposity index (P < 0.05). Glucose, insulin and HOMA-IR were significantly reduced and R-QUICKI was significantly increased by MO 400 (P < 0.001). Mean tissue level of leptin and vaspin were significantly reduced, adiponectin, omentin and GLUT-4 expression were increased significantly by MO 400 (P < 0.01). MO 400 significantly suppressed FAS and HMG-CoA reductase and increased mRNA expression of MC4R and PPAR-α (P < 0.01). Eight weeks administration of MO hard gelatin capsules to obese patients showed significant reduction of the average BMI, TC and LDL compared to the baseline values (p < 0.05).Our results presented a scientific evidence for the traditional use of M. oleifera leaves as antiobesity herbal medicine.