Faculty of Agriculture, Yamagata University, Tsuruoka, Yamagata 997-8555, Japan.
Nutrients. 2012 Oct 22;4(10):1518-26. doi: 10.3390/nu4101518.
Anti-obesity effects of onion extract were determined in obesity and diabetes-prone Zucker diabetic fatty rats by measuring the efficacy of markers concerned with diabetes and obesity. Body and adipose tissue weights in 5% of onion extract-fed group were found to be significantly lower than the control group without onion extract. Fasting blood glucose and HOMA-IR levels were also improved, although the serum insulin and leptin levels did not show any remarkable difference. Serum triglyceride and free fatty acid levels in both the 3% and 5%-fed group were found to be reduced compared to the control group. Additionally the feeding of the onion extract increased the glucose tolerance. These results suggest that dietary onion extract is beneficial for improving diabetes by decreasing lipid levels. We also examined differentiation ability of rat white preadipocyte cells using the onion extract and its sulfur-containing components. Cycloalliin, S-methyl-L-cysteine, S-propyl-L-cysteine sulfoxide, dimethyl trisulfide, especially S-methyl-L-cysteine sulfoxide were reported to be effective in inhibiting formation of oil drop in the cells, suggesting that these compounds may be involved in the anti-obesity effect of the onion extract.
通过测量与糖尿病和肥胖相关标志物的功效，来确定洋葱提取物对肥胖和糖尿病易感 Zucker 肥胖型糖尿病大鼠的抗肥胖作用。结果发现，5%洋葱提取物喂养组的体重和脂肪组织重量明显低于未添加洋葱提取物的对照组。空腹血糖和 HOMA-IR 水平也有所改善，尽管血清胰岛素和瘦素水平没有显示出任何显著差异。与对照组相比，3%和 5%喂养组的血清甘油三酯和游离脂肪酸水平均降低。此外，洋葱提取物的喂养增加了葡萄糖耐量。这些结果表明，饮食中摄入洋葱提取物通过降低脂质水平有助于改善糖尿病。我们还使用洋葱提取物及其含硫成分检查了大鼠白色前体脂肪细胞的分化能力。环蒜氨酸、S-甲基-L-半胱氨酸、S-丙基-L-半胱氨酸亚砜、二甲基三硫化物，尤其是 S-甲基-L-半胱氨酸亚砜被报道能有效抑制细胞内油滴的形成，表明这些化合物可能参与了洋葱提取物的抗肥胖作用。
