Health Care Research Center, Nisshin Pharma Inc., Saitama 356-8511, Japan.
Research Center for Basic Science, Research and Development, Quality Assurance Division, Nisshin Seifun Group, Inc., Saitama 356-8511, Japan.
Molecules. 2020 Oct 14;25(20):4694. doi: 10.3390/molecules25204694.
Testosterone plays an important role in male sexual characteristics and maturation, and decreased testosterone levels increase the risk of several diseases. Recently, onion extract rich in cysteine sulfoxides, which are amino acids unique to onions, has been reported to alleviate age-related symptoms resulting from decreased testosterone levels in males. However, the mechanism underlying the suppression of low testosterone levels by cysteine sulfoxides has not been elucidated. In this study, we found that onion extract containing cysteine sulfoxides enhanced progesterone, a precursor of testosterone, in mouse testis-derived I-10 tumor cells. Furthermore, cysteine sulfoxides activated protein kinase A (PKA) and cyclic adenosine monophosphate response element-binding protein, which are key factors in steroidogenesis. These results suggest that cysteine sulfoxides enhance steroid hormone production via activation of the PKA signaling pathway.
睾酮在男性性特征和成熟中发挥着重要作用，而睾酮水平降低会增加多种疾病的风险。最近，富含半胱氨酸亚砜的洋葱提取物已被报道可缓解男性因睾酮水平降低而导致的与年龄相关的症状，这种提取物中含有氨基酸，而这种氨基酸是洋葱所特有的。然而，半胱氨酸亚砜抑制低睾酮水平的机制尚未阐明。在这项研究中，我们发现含有半胱氨酸亚砜的洋葱提取物可增强在老鼠睾丸衍生的 I-10 肿瘤细胞中的孕激素（睾酮的前体）。此外，半胱氨酸亚砜激活了蛋白激酶 A（PKA）和环磷酸腺苷反应元件结合蛋白，它们是类固醇生成中的关键因素。这些结果表明，半胱氨酸亚砜通过激活 PKA 信号通路来增强甾体激素的产生。
