Effect of rice bran extract on pancreas of rats fed a high-fat diet

As the water extract of rice bran (R) was shown to ameliorate the pre-diabetes found in rats fed a high-fat diet [1], the effect of R on the pancreas of the animal was investigated. Male Sprague Dawley rats were arranged into 5 groups, 8 rats each. Four groups of high-fat (65% of total calories from fat) fed rats (HF) were studied against a control group (C) those were fed with standard chow. Leaving a group as the high-fat feeding alone, the other three were also co-fed with either 2,205 mg (HFR1) or 4,410 mg (HFR2) R/kg rat weight/day or 19.1 mg metformin/kg rat weight/day (HFM). The HF showed a significant increase in mean ± SEM of body weight gain, relative weight of visceral fat and liver but a decrease in that of pancreas when compared to C (0.49 ± 0.01 versus 0.58 ± 0.01 g per 100 g rat wt; p < 0.05). The values were improved in HFR1, HFR2 and HFM. The relative gene expression of insulin receptor substrate-2, glucose transporter-2 and glucokinase were significantly lower in HF than C. Both R and M were able to increase the relative expression of the two former genes. Hematoxylin-eosin staining of the pancreas showed larger islets area in HF than C. Senescence associated beta-galactosidase staining showed the denser stained materials in HF than C (0.488 ± 0.012 versus 0.407 ± 0.007; p < 0.001) indicating pancreatic senescence in HF. The staining in HFB1, HFB2 and HFM (0.421 ± 0.008, 0.446 ± 0.012 and 0.430 ± 0.009, respectively) were significantly less than HF (p < 0.05). In conclusion, there were substances in R those can reduce pancreatic senescence found in high-fat feeding rats. Therefore, further verification of those substances in R is worth conducted.

[1] Kandee, et al, Thammasat Med J 2009;9:140 – 7.