Melatonin

The protective action of melatonin can be manifested in our study following the induction of hyperlipidemia in rodent animals or rats to counteract the harmful effects of excess fat. 30 wistermale rats, divided into 3 groups; 10 of them were subjected to normal diet (control group) group A with melatonin, group B had a diet rich in lipid(atherogenic diet)for three weeks without melatonin injection, while group C taking atherogenic diet but with melatonin injection (intraperitoneal) with serial estimation of serum cholesterol ,triglyceride ,LDL and  VLDL through blood sample of trunk blood (cardiac puncture of the rat) for a period  from 25 Feb. 2013 to 25 April 2013. Enhanced catabolism of cholesterol to bile acids is likely studied by an increase in fecal bile acid excretion following melatonin treatment as will be seen in general stool examination (G.S.E.) of the rats. In group B marked increase in serum cholesterol, VLDL and triglyceride level following dietary regime (followed by) slight reduction in serum cholesterol and triglyceride level after melatonin injection as seen in group C , associated with high bile salts level in stool examination ,matching with no response as seen in group A .These findings suggest that the hypolipidemic effect of melatonin may work through the augmentation of endogenous cholesterol clearance mechanisms especially in cases with induced or secondary hyperlipidemia, this is accompanied by the lowering of the triglyceride fraction associated with low density lipoproteins.