Supplementation of Stingless Bee Honey from Heterotrigona itama Improves Antiobesity Parameters in High-Fat Diet Induced Obese Rat Model

Abstract

Heterotrigona itama is a common stingless bee species found in Southeast Asia. Studies on the health benefits of its honey are limited in comparison with other stingless bee species. This study examines the antiobesity benefits found in stingless bee honey (SBH) from H. itama. The parameters used to measure the benefits were weight change, morphological structures, and biochemical characteristics. The research was conducted by using rats that were given a high-fat diet (HFD). In total 48 male Sprague Dawley (SD) rats were given a formulated HFD to increase the levels of obesity, the HFD was administered with a value of 0.68 g/cm2. The duration of the treatment was six weeks, and the results show that the induction obesity using the HFD was successful. Following this, the rats were then treated with SBH (at dosages of 1000 mg/kg, 750 mg/kg or 500 mg/kg), with orlistat or with a placebo. Compared with typical obesity treatment methods, the one that used the three dosages of SBH showed a higher reduction in body mass index (BMI), percentage of body weight gain, adiposity index, and relative organ weight (ROW). The levels of liver enzymes (ALT, AST, and ALP) were also significantly lower in SBH-treated groups. The levels of triglycerides and LDL-cholesterol were significantly lower, while the level of HDL-cholesterol was significantly higher in comparison with the control obese group. In terms of morphological structures, the number of adipocyte cells was reduced, and the hepatocytes found in the liver were less prone to rupturing when treated with SBH. In conclusion, the administration of SBH led to an improvement in indicators associated with obesity reduction. SBH also possesses a hepatoprotective potential which can reduce the health risks related to obesity.

Figures

Figure 1

Photomicrographs show the effects of treatment and dosages of stingless bee honey (SBH) or orlistat on liver histology of obese rats, under a light microscope and following the processes of H&E with 40 x magnification. Groups: (a) normal diet rats; (b) control obese rats; (c) obese rats treated with 1000 mg/kg SBH; (d) obese rats treated with 750 mg/kg SBH; (e) obese rats treated with 500 mg/kg SBH. Black arrow (→) represents fat cells; BV: blood vessel.

Figure 2

Photomicrographs show the effects of different dosages of stingless bee honey (SBH) or orlistat on visceral fatty tissue histology in obese rats, under a light microscope and after completing the processes of H&E stain with 40 x magnification. Groups: (a) normal rats; (b) control obese rats; (c) obese rats treated with 1000 mg/kg SBH; (d) obese rats treated with 750 mg/kg SBH; (e) obese rats treated with 500 mg/kg SBH.

Figure 3

Photomicrographs show the effects of three different treatments and dosages of stingless bee honey (SBH) in liver tissue of obese rats, under a scanning electron microscope (ScEM) at 2500x magnification. (a) Group 1, normal architecture of liver surface (normal sinusoid and intact hepatocytes); (b) Group 2, obese rats' liver fed with HFD received no treatment showed presence of fat cells and have damage hepatocytes, damage sinusoid and rough surface; (c) Group 3, obese rats' liver fed with HFD and treated with 1000 mg/kg SBH showed fibrin formation, dilated sinusoid, and nonintact hepatocytes; (d) Group 4, obese rats' liver fed with HFD and treated with 750 mg/kg SBH showed smooth appearance and a few insignificant presence of fat cells; (e) Group 5, obese rats' liver fed with HFD and treated with 500 mg/kg SBH showed normal-like structure and a few insignificant presence of fat cells. Fat cells are indicated in red circles. H= hepatocyte; S= sinusoid.