The role of rice bran extract on acetyl CoA carboxylase in liver of rats fed a high-fat diet

Rice bran water extract (RBE) was shown to reduce fat mass in rats fed a high-fat diet [1]. The involvement of RBE in metabolic alteration were investigated in 7 groups of Sprague Dawley rats, 8 rats each. High-fat fed group 3 to 7 were either co-treated daily with RBE (220.5, 2205, 4410mg/kg) or metformin (19.10, 38.20mg/kg). Oral glucose tolerance was tested at the end of forth week. Rats were killed and specimens were collected. The results showed that the mean±SEM of abdominal fat weight, epididymal fat cell size and triglyceride level in blood and liver were increased whereas cholesterol in high-density lipoprotein was decreased in rats fed a high-fat diet alone as compared to rats fed with chow (7.65±0.29 vs. 4.73±0.39g.; 4919.76±453.59 vs. 2835.23 ±249.15µm2; 44.67±2.72 vs. 35.00±2.02mg/dL; 2.50±0.26 vs. 1.48±0.08mg/mL; 67.14±1.62 vs. 77.20±2.82mg/dL, respectively). At least 2205mg RBE/kg or 19.10mg metformin/kg were able to significantly reduce abdominal fat weight and triglyceride levels in liver. ACC activity was increased in high-fat feeding group but the activities retuned to normal when they were also received RBE or metformin, though there was no statistic significance. In conclusion, fatty acid flux might induce fat synthesis in liver as an initial step in increasing fat accumulation [2]. Both RBE and metformin were able to reduce the alteration.

Keywords: Rice bran, acetyl CoA carboxylase, high-fat diet

Acknowledgement: Research Unit, Faculty of Medicine, Thammasat University, the National Research Council of Thailand.

References: 1 Kandee N et al. (2009) Thamm Med J 9:140–7. 2 Samuel VT, Peterson KF, Shulman GI (2010) Lancet 375:2267–77.