Effects of Liver Hydrolysate on the Blood Glucose in Metabolic Syndrome Model Rats (SHR/NDmcr-cp)

Abstract

Insulin resistance associated with visceral fat obesity has been suggested to be the pathological basis of metabolic syndrome. Many studies have demonstrated increased oxidant stress in diabetic patients and animal models of diabetes mellitus. In this study, the effect of liver hydrolysate administration on the blood glucose was examined in SHR/NDmcr-cp (SHR-cp) rats that show spontaneously occurring metabolic syndrome-like abnormalities. The SHR-cp rats were fed diets containing 5% liver hydrolysate for 12 weeks, and the fasting blood glucose and HbA1c were determined every 3 weeks. After administration of the liver hydrolysate-containing feed for 12 weeks, an oral glucose tolerance test was conducted and the plasma angiotensin II (AngII) concentrations were determined. The liver hydrolysate administration had no effect on the blood insulin levels in the oral glucose tolerance test, but significantly inhibited the d-glucose-induced increases of the blood glucose levels. Furthermore, the liver hydrolysate had almost no effect on the fasting blood glucose level, but tended to inhibit the increase of HbA1c. The plasma AngII concentration after the 12-week administration of liver hydrolysate remained significantly lower than that in the control group. These results indicate that a component of liver hydrolysate inhibits d-glucose-induced increase of the blood glucose level, and may improve insulin resistance. The angiotensin converting enzyme (ACE)-inhibiting effect and antioxidant effect of liver hydrolysate may be involved in this effect.