The effect of rice-bran extract from Khao-Dawk Mali 105 variety on abdominal fat deposition in rats fed a high-fat diet

Abstract

showed antioxidant property, total phenolic compounds and essential oils. The effect of RBEE was studied in SpragueDawley rats fed with a high-fat diet. Three doses of RBEE, 220.5, 2,205 and 4,410 mg/kg rat weight, in comparisonto metformin and a high fat diet fed rats were co-fed with the high-fat diet. After the treatment for 4 weeks, ratsfed a high-fat diet tended to increase in epididymal fat accumulation when compared to rats fed chow (7.06 ± 0.35g versus g 6.51 ± 0.14). This was signifi cantly reduced to 4.97 ± 0.17 g and 5.73 ± 0.27 g when rats were co-fedwith RBEE 220.5 and 2,205 mg/kg, respectively. Liver weights were signifi cantly reduced to 13.77 ± 0.62 g, 12.87 ±0.25 g and 13.26 ± 0.39 g when rats were co-fed with RBEE 220.5, 2,205 and 4,410 mg/kg, respectively comparedto 15.10 ± 0.41 g in rats fed a high-fat diet. The results were concordance with the increased epididymal fat cell size(5,444.39 ± 550.10 μm² versus 4,800.90 ± 513.71 μm²) and triglyceride content in liver (1.73 ± 0.24 mg/mL versus1.39 ± 0.07 mg/mL) of rats fed a high-fat diet. These increasing cell size and liver triglyceride content were signifi cantlyreduced when rats were co-fed with either RBEE or metformin. In addition, the results showed that RBEE had no effecton area under the curve of glucose tolerance test (AUC-G), fasting blood insulin, homeostasis model assessmentof pancreatic β-cell function (HOMA-β) and homeostasis model assessment of relative insulin resistance (HOMA-IR).These observations may be due to high variation in most of these values. In conclusion, the effect of RBEE on theamelioration of the abnormal energy metabolism was similar to that of rice-bran water extract. It is worth to further fi ndout which active substance or substances of RBEE were able to ameliorate the abnormal energy metabolism in vitro.

Key words: Obesity, Rice bran, High fat diet