Effects of thiol antioxidant β-mercaptoethanol on diet-induced obese mice.

AIMS: Obesity and insulin resistance are associated with increased oxidant stress. However, treatments of obese subjects with different types of antioxidants often give mixed outcomes. In this work, we sought to determine if long-term supplementation of a thiol antioxidant, β-mercaptoethanol, to diet-induced obese mice may improve their health conditions. MAIN
METHODS: Middle-age mice with pre-existing diet-induced obesity were provided with low concentration β-mercaptoethanol (BME) in drinking water for six months. Animals were assessed for body composition, gripping strength, spontaneous physical and metabolic activities, as well as insulin and pyruvate tolerance tests. Markers of inflammation were assessed in plasma, fat tissue, and liver. KEY
FINDINGS: BME-treated mice gained less fat mass and more lean mass than the control animals. They also showed increased nocturnal locomotion and respiration, as well as greater gripping strength. BME reduced plasma lipid peroxidation, decreased abdominal fat tissue inflammation, reduced fat infiltration into muscle and liver, and reduced liver and plasma C-reactive protein. However, BME was found to desensitize insulin signaling in vivo, an effect also confirmed by in vitro experiments. SIGNIFICANCE: Long-term supplementation of low dose thiol antioxidant BME improved functional outcomes in animals with pre-existing obesity. Additional studies are needed to address the treatment impact on insulin sensitivity if a therapeutic value is to be explored.