Korean solar salts reduce obesity and alter its related markers in diet-induced obese mice

BACKGROUND/OBJECTIVES: The aim of this experiments was to show anti-obesity effects of Korean solar salt from different salt fields in diet-induced obese mice. SUBJECTS/METHODS: Diet-induced obesity (DIO) was induced by a high-fat diet (HFD; 45% cal from fat) in C57BL/6J mice for eight weeks. The mice were fed with the designated diets (chow diet for Normal, HFD for Control, 0.47%-salt-mixed HFD for purified salt (PS), Guerande solar salt from France (SS-G), solar salt from Y salt field (SS-Y), solar salts from T salt field (SS-T) and S salt field (SS-S)) for another eight weeks. We checked body weight, food efficiency ratio (FER) and tissue weights (liver and epididymal adipose tissue (EAT)), and observed serum concentrations of triacylglycerol (TG), total cholesterol (TC), leptin and insulin. We also evaluated gene expressions of adipogenic / lipogenic mRNAs of C/EBPα, PPARγ and FAS and beta-oxidation-related factors (PPARα and CPT-1) in liver and EAT. The mineral composition of salt samples were analyzed using inductively coupled plasma optical emission spectrometry (ICP-OES). RESULTS: SS-T and SS-S significantly reduced body weight gain, FER, and weight of EAT compared to control and other samples (P < 0.05). SS-T and SS-S also significantly decreased serum levels of TG, TC, leptin and insulin (P < 0.05). SS-T and SS-S suppressed expressions of adipogenic / lipogenic mRNAs in liver and EAT, while promoting expression of beta-oxidation-related factors. The lowest sodium concentration was observed in SS-T (30.30 ± 0.59%), and the lowest sodium-to-potassium (Na/K) ratio was found in SS-S (17.81). CONCLUSIONS: Our study shows that well-processed Korean solar salt may have anti-obesity effects in vivo, probably owing to its differences in mineral composition and other components, presumably resulting from the manufacturing processes. Further research is needed into the mechanism and to explore optimal manufacturing processes.