Abstract:

Objective: To investigate the effect of dietary Aetobatus flagelum on lipid metabolism in rats for improving the utilization value of low-value aquatic products. Methods: Twenty-one male SD rats were randomly divided into 3 groups, including normal control group (fed normal diet containing casein), low-dose treatment group (fed normal diet containing 10% of Aetobatus flagelum meat powder and 10% of casein) and high-dose treatment group (fed normal diet containing 20% of Aetobatus flagelum). After 28 days of consecutive administration, all mice were sacrificed to measure triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), free fatty acid (FFA) contents in serum and TG, TC and phospholipids contents in liver and the activities of enzymes related to lipids metabolism, such as malic enzyme (ME), glucose-6-phosphate dehydrogenase (G6PDH), fatty acid synthase (FAS), phosphatidic acid phosphophydrolase (PAP) and carnitin palmitoyl transferase (CPT). Results: Compared with the control group, serum TG, TC and FFA levels exhibited a significant decrease in both the treatment groups (P < 0.05). Both low- and high-dose treatments had no obvious effect on serum HDL-C level but resulted in an obvious reduction of arteriosclerosis index in rats. Moreover, a significant decrease in TG and TC contents in liver was observed in both the treatment groups when compared with the control group (P < 0.05). The activities of G6PDH, ME, FAS and PAP in liver were all inhibited by dietary Aetobatus flagelum, whereas no obvious effects on the activity of hepatic CPT and mRNA expression of FAS, CPT-1, CPT-2 genes were observed. Conclusion: The above results indicate that the reduction of serum lipids by dietary Aetobatus flagelum is related to the down-regulation of hepatic lipids synthesis. Dietary Aetobatus flagelum can attenuate the accumulation of serum and hepatic lipids through reducing the synthesis of hepatic fatty acid and TG.

Key words: Aetobatus flagellum, hypolipidemic effect, lipid metabolism, amino acid composition, enzyme activity