Antioxidative and Fat Accumulation Inhibitory Effects of Heated Garlic Skin Ethanol Extract on 3T3-L1 Adipocytes

Garlic skin is an agricultural by-product generated during the garlic harvesting process, and has been regarded as a waste material.This study aimed to compare the antioxidant activity and anti-obesity effects of ethanol extracts of garlic skin subjected to heat treatment at 0C (0-GSE), 140C (140-GSE), 170C (170-GSE), and 200C (200-GSE).As the heat treatment temperature of the garlic skin increased to 200C, the antioxidant activity also increased.Fat accumulation was significantly inhibited by 22% at 75 g/mL of 140-GSE in 3T3-L1 adipocyte compared to the adipocytes (AD) group.The 100 g/mL 140-GSE treatment of 3T3-L1 adipocytes significantly decreased the expression level of genes related to adipogenic differentiation, including peroxisome proliferator-activated receptor (ppar), CCAAT enhancer-binding protein- (c/ebp-), sterol regulatory element-binding protein 1c (srebp-1c), adipocyte protein 2 (ap2), fatty acid synthase (fas), and stearoyl-CoA desaturase 1 (scd1) by 47%, 54%, 58%, 84%, 66%, and 78%, respectively compared to the AD group.In addition, the expression levels of proteins related to adipogenic differentiation, such as PPAR, C/EBP-, SREBP-1C, AP2, FAS, and SCD1 were significantly reduced by 62%, 18%, 25%, 87%, 55%, and 62%, respectively, compared to the AD group.In conclusion, the antioxidative and anti-obesity effects of heat-treated garlic skin ethanol extract were observed, confirming its potential as a sustainable functional material.