ABSTRACT

Effect of fermented soybean oils
on the differentiation of 3T3-L1 pre-adipocytes and high fat diet-feeding C57BL/6J mice



Kim, Seon-Woong
Dept. of Food Biotechnology,
Graduate School of Woosuk University
(Directed by Prof. Oh, Chan-Ho)

This study manufactured fermented soybean oil using a fermenting strain commonly processed for soybeans and evaluated its anti-obesity activity. According to the evaluation results of anti-obesity activity of fermented soybean oil, cytotoxicity was not observed in 3T3-L1 preadipocytes at concentrations below 50 μg/ml. The degree of neutral fat accumulation aligned with the outcome using Oil Red O stain, which serves as an indicator of intracellular lipid accumulation. The fat was reduced by 34.2% at maximum in BLO group treated at a concentration of 50 μg/mL, proving the inhibitory effect of adipocyte differentiation.
The concurrent treatment of fermented soybean oil and differentiation induction medium (MDI) decreased the of PPARγ and C/EBPα gene expression at a concentration of 50 μg/mL, and blocked adipocyte differentiation by increasing adiponectin gene expression. The inhibitory effect of adipocyte differentiation was the greatest in BLO group. C57/BL6J mice were examined for 4 weeks by dividing into normal diet group (N), high-fat diet group (C), a group fed high-fat diet combined with regular soybean oil (SO), a group fed non-fermented soybean oil (NF) and a group fed 5% fermented soybean oil (BA, BS, LBA, BLO) to identify the effect of soybean oil on weight, adipose tissue weight (epididymal fat, perirenal fat), serum lipid level, and adiponectin, insulin and leptin levels in mice with high fat diet-induced obesity. The weight, adipose tissue weight, and serum lipid level of high-fat diet group (C) increased drastically compared to those of normal diet group. In contrast, the group fed on a diet combined with fermented soybean oil had substantial decreases in weight, adipose tissue weight, total serum cholesterol, LDL-cholesterol and serum triglyceride compared to those of high-fat diet group (C). Moreover, soybean oil was found to be effective in BLO group. In conclusion, fermented soybean oil has positive effects in prohibiting adipocyte differentiation, reducing weight and adipose tissue weight (epididymal fat, perirenal fat) increased by high-fat diet, and improving serum lipid composition. Therefore, fermented soybean oil can be used for functional food as a new food material with anti-obesity activity.