Effects of Melatonin on Lipid Metabolism and Circulating Irisin in Sprague-Dawley Rats with Diet-Induced Obesity

Abstract

Melatonin, a pivotal photoperiodic signal transducer, may work as a brown-fat inducer that regulates energy balance. Our study aimed to investigate the effects of melatonin treatment on the body fat accumulation, lipid profiles, and circulating irisin of rats with high-fat diet-induced obesity (DIO). Methods: 30 male Sprague-Dawley rats were divided into five groups and treated for 8 weeks: vehicle control (VC), positive control (PC), MEL10 (10 mg melatonin/kg body weight (BW)), MEL20 (20 mg/kg BW), and MEL50 (50 mg/kg BW). The vehicle control group was fed a control diet, and the other groups were fed a high-fat and high-calorie diet for 8 weeks to induce obesity before the melatonin treatment began. Melatonin reduced weight gain without affecting the food intake, reduced the serum total cholesterol level, enhanced the fecal cholesterol excretion, and increased the circulating irisin level. Melatonin downregulated the fibronectin type III domain containing 5 (FNDC5) and lipoprotein lipase (LPL) mRNA expressions of inguinal white adipose tissue (iWAT) and induced the browning of iWAT in both the MEL10 and MEL20 groups. Conclusion: Chronic continuous melatonin administration in drinking water reduced weight gain and the serum total cholesterol levels. Additionally, it enhanced the circulating irisin, which promoted brite/beige adipocyte recruitment together with cholesterol excretion and contributed to an anti-obesity effect.

FGF19 protects skeletal muscle against obesity‐induced muscle atrophy, metabolic derangement and abnormal irisin levels via the AMPK/SIRT‐1/PGC‐α pathway

“…FGF19 administration reversed this reduction and enhanced circulating irisin levels. Our results are consistent with some previous studies 70,71 . However, the opposite results have also been found in obese patients and animals 14 .…”

Melatonin activates ABCA1 via the BiP/NRF1 pathway to suppress high-cholesterol-induced apoptosis of mesenchymal stem cells

“…As shown here and in another study, DIDS combined with melatonin abolished cholesterol efflux mediated by ABCA1 without significantly changing the levels of ABCA1 or ROS [22]. The various effects of melatonin such as lowering oxidative stress, regulating lipid metabolism, and inducing receptor-mediated signal transduction could be involved in protecting UCB-MSC apoptosis under a high cholesterol environment [23][24][25]. Considering that intracellular cholesterol regulation is critical for oxidative stress, which activates numerous signaling pathways, including signal molecules related to oxygen and lipids, our proposed target can be of therapeutic importance.…”

RORα Regulates Odontoblastic Differentiation and Mediates the Pro-Odontogenic Effect of Melatonin on Dental Papilla Cells

“…Although whether RORα is a true nuclear receptor of melatonin remains debatable [ 72 ], RORα mediates many important physiological and pharmacological effects of melatonin, including circadian rhythm, oxidative stress, and immune response [ 48 , 50 , 73 ]. Melatonin is a multifunctional molecule involved in various biological processes [ 14 , 15 , 16 , 17 , 18 , 74 ]. Recently, melatonin has become an important research area, with the primary focus on its potential in regenerative medicine [ 22 ].…”