Natural Honey Proteins Prevent Diet-Induced Obesity and Metabolic Disorders in Rats

Previous studies have shown that oral whole honey reduces weight gain in rats on a normal diet (ND) or high-fat diet (HFD) and suppresses inflammation by modulating immunological cytokines in human neutrophils and macrophages. We hypothesize that the honey proteins (HP) are responsible for the reduced weight gain in rats on ND and HFD and that HP would alleviate obesity parameters. To test this, proteins were isolated from acacia honey through the salting-out method. Wistar rats (N = 24) were randomized to get ND or HFD for 4 weeks, then further randomized to four groups and treated with HP or saline for another 4 weeks. Energy intake (EI), body weight gain, EI per gram body weight gain, serum glucose, and lipids were measured. Expression of adipose tissue genes fatty acid binding protein (FABP), lipase C (LIPC), and apolipoprotein A-1 (APOA1) was evaluated through the quantitative polymerase chain reaction. HFD increased the body weight versus ND in weeks 1-4. HP for the next 4 weeks reduced weight gain in ND-HP and HFD-HP groups versus saline controls (P < .01). EI was not significantly different among groups. However, EI per gram body weight gain among groups was markedly different (P < .01), demonstrating reduced weight gain efficiency by HP (P < .01). HP reduced glucose in ND but not in HFD groups. Triglycerides were lower in both HP groups. The expressions of FABP, LIPC, and APOA1 genes were significantly increased (P < .05) in HP-treated HFD rats. Collectively, weight gain efficiency was remarkably reduced without altering EI in rats following the HP treatment, suggesting HP increased metabolic rate or substrate partitioning. Studies of HP are suggested in humans.