Hypoglycemic and hypolipidemic effects of protein hydrolysates from zebra blenny (Salaria basilisca) in alloxan-induced diabetic rats

Abstract

The present study investigates the hypoglycemic and hypolipidemic effects of protein hydrolysates obtained from zebra blenny (Salaria basilisca) muscles treated with three different crude alkaline protease extracts in alloxan-induced diabetic rats (AIDR). Analysis of amino acid composition revealed that zebra blenny protein hydrolysates (ZBPHs) were valuable sources of essential amino acids and rich in leucine, which is one of the active ingredients for blood glucose control by inducing insulin release in both rats and humans. Treatment of AIDR with ZBPHs revealed a significant inhibition of α-amylase activity in serum and the intestine, as well as a reduction of blood glucose and glycated hemoglobin (HbA1c) levels in diabetic rats. Further, ZBPHs also decreased significantly the triglyceride (TG), total-cholesterol (TC) and LDL-cholesterol (LDL-c) levels in the serum and liver of diabetic rats, while they increased the HDL-cholesterol (HDL-c) level, which helped to maintain the homeostasis of blood lipids. Furthermore, ZBPHs exhibited potent protective effects against heart attack markers by reversing myocardial enzyme serum back to normal levels. ZBPHs may also exert significant protective effects on liver function, evidenced by a marked decrease in the level of serum bilirubin as well as in the activities of alanine aminotransferase (ALT), alkaline phosphatase (ALP), and gamma-glutamyl transpeptidase (GGT). These beneficial effects of ZBPHs were confirmed by histological findings in the hepatic and pancreatic tissues of diabetic rats. Indeed, they avoid lipid accumulation in the hepatocytes and protect the pancreatic β-cells from degeneration. Overall, the findings of the current study indicate that ZBPHs significantly attenuated hyperglycemia and hyperlipidemia in AIDR.