Department of Physiology, College of Basic Medical Sciences, Harbin Medical University, Harbin, China.
J Ovarian Res. 2018 Jun 21;11(1):51. doi: 10.1186/s13048-018-0421-0.
Menopause is the most important sign of aging in women, and the ovary is the organ most sensitive to aging. Quercetin is a potential antioxidant and free radical scavenger that is widely found in fruits, vegetables, and leaves. However, the effect of quercetin on ovarian aging has not been elucidated, and the mechanism underlying its antioxidative effect remains unclear. The purpose of the current study was to investigate whether quercetin protects ovarian function by decreasing oxidative stress.
In an in vivo experiment, female menopausal rats (12 months old) were intragastrically administered quercetin at three doses (12.5 mg/kg, 25 mg/kg, and 50 mg/kg) for 90 days, and the estrous cycles were determined by vaginal smearing. In an in vitro experiment, rat primary ovarian granulosa cells were cultured and treated with HO (400 μM) alone or HO plus quercetin at 5 μM, 20 μM, or 50 μM. The levels of the hormones estradiol (E), progesterone (P), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were detected by radioimmunoassay. The serum levels of total antioxidant capacity (T-AOC), superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GSH-PX) and glutathione S-transferase (GST) were examined. The expression levels of the oxidative stress-related genes SOD-1, catalase (CAT) and glutathione synthetase (GSS) in the ovaries and ovarian granulosa cells were detected by Western blot.
The in vivo results demonstrated that quercetin had no effects on ovarian morphology, hormone secretion, or the estrous cycle in menopausal rats. Although no significant changes were detected in the serum levels of T-AOC, SOD, GSH, GSH-PX, and GST between the quercetin and control groups, the mRNA and protein expression levels of the oxidative stress-related genes SOD-1, CAT and GSS in menopausal rat ovaries were increased by low-dose quercetin. Moreover, the in vitro results demonstrated that quercetin significantly rescued the decrease in cell viability by HО-induced oxidative stress and enhanced the HO-induced decrease in expression of oxidative stress-related proteins.
Together, the results of this study indicated that quercetin increased the antioxidant capacity of the ovary by upregulating the expression of some oxidative stress-related genes both in vivo and in vitro.
绝经是女性衰老最重要的标志，而卵巢是对衰老最敏感的器官。槲皮素是一种潜在的抗氧化剂和自由基清除剂，广泛存在于水果、蔬菜和叶子中。然而，槲皮素对卵巢衰老的影响尚未阐明，其抗氧化作用的机制尚不清楚。本研究旨在探讨槲皮素是否通过降低氧化应激来保护卵巢功能。
在体内实验中，12 月龄绝经雌性大鼠（12 月龄）灌胃给予三种剂量（12.5mg/kg、25mg/kg 和 50mg/kg）的槲皮素 90 天，通过阴道涂片确定动情周期。在体外实验中，培养大鼠原代卵巢颗粒细胞，并用 400μM 的 HO 单独或 HO 加 5μM、20μM 或 50μM 的槲皮素处理。放射免疫法检测激素雌二醇（E）、孕酮（P）、卵泡刺激素（FSH）和黄体生成素（LH）水平。检测血清总抗氧化能力（T-AOC）、超氧化物歧化酶（SOD）、谷胱甘肽（GSH）、谷胱甘肽过氧化物酶（GSH-PX）和谷胱甘肽 S-转移酶（GST）水平。Western blot 检测卵巢和卵巢颗粒细胞中氧化应激相关基因 SOD-1、过氧化氢酶（CAT）和谷胱甘肽合成酶（GSS）的表达水平。
体内实验结果表明，槲皮素对绝经大鼠的卵巢形态、激素分泌或动情周期没有影响。虽然在槲皮素和对照组之间，血清 T-AOC、SOD、GSH、GSH-PX 和 GST 水平没有显著变化，但低剂量槲皮素可增加绝经大鼠卵巢中氧化应激相关基因 SOD-1、CAT 和 GSS 的 mRNA 和蛋白表达水平。此外，体外实验结果表明，槲皮素可显著挽救 H0 诱导的氧化应激引起的细胞活力下降，并增强 H0 诱导的氧化应激相关蛋白表达的下降。
综上所述，本研究结果表明，槲皮素通过体内和体外上调某些氧化应激相关基因的表达，增加卵巢的抗氧化能力。
