The effects of different doses of melatonin on lipid peroxidation in diet-induced hypercholesterolemic rats

Abstract

This study aims to see in an animal experiment how differently the low and high doses of melatonin affect the antioxidant status and peroxidation of lipids. Forty-two male Wistar-Albino rats weighing about 200 gr (180-220) aged 6-7 months were used. Of these rats, 12 were fed with normal rat chow for 12 weeks. The latter ones were divided into two groups, each containing 6 rats. Group 1 (control group) received daily intraperitoneal injections of NaCl (0.9%; w/v). Group 2 was injected ethanol daily (4%; v/v; i.p.) to see the effects of ethanol in which we dissolved melatonin. Thirty rats were fed with a diet enriched with cholesterol (2%; w/w), cholic acid (0.5%; w/w) and propilthyouracil (0.5%; w/w) for 12 weeks. These rats were divided into three groups each containing 10 rats. The low-dose group received melatonin 1 mg/kg/d; i.p. (group 3), the high-dose group received melatonin in a dose of 10 mg/kg/d; i.p. (group 4), and only the cholesterol group did not get any vehicle (group 5). Total cholesterol (TC), LDL cholesterol (LDL-C), total antioxidant capacity (TAC), oxidized LDL (oLDL) and TBARS lelvels were measured in all groups. The produced high-cholesterol diet increased LDL cholesterol. Melatonin decreased the extent of this plasma lipoprotein increase and also prevented the oxidation of it. This effect was clearer when the dose was higher. Antioxidant status seems to be also Ref. 33). Full Text in PDF www.elis.sk.

REV-ERB ALPHA Polymorphism Is Associated with Obesity in the Spanish Obese Male Population

“…Likewise, melatonin has been found in higher levels in lean subjects. Melatonin is synthesized in the pineal gland and not only regulates the circadian and seasonal rhythms but also has antioxidant effects and is implicated in the control of glucose and lipid metabolism [34] , [35] . Previous studies showed higher levels of nocturnal melatonin in obese than in BMI-matched type 2 diabetes and lean groups, without any differences among groups at other moments during the day [36] .…”

Dietary Sources and Bioactivities of Melatonin

“…Dyslipidemia is commonly accompanied with other disorders related to metabolic syndromes. Melatonin has been observed to effectively improve dysplipidemia by reducing LDL cholesterol levels, total cholesterol and triglycerides, but increase HDL-C, glucose tolerance and antioxidant potency due to its potent antioxidant effects [270,271,272]. …”

Endothelial dysfunction and melatonin

“…At the same time there was prevention to a drop of high-density lipoproteins (HDL) blood concentration with an increase in the HDL/LDL ratio; besides, there was a significant suppression of lipid peroxidation in the tissues of the internal organs. Among other mechanisms, this protected cell membranes, including those of vascular endothelium, against oxidative damage [23,26,40].…”