Department of Physiology, College of Veterinary Medicine and Bio-Molecular Informatics Center, Konkuk University, Seoul 143-701, Korea.
Korean J Physiol Pharmacol. 2013 Apr;17(2):175-80. doi: 10.4196/kjpp.2013.17.2.175. Epub 2013 Apr 10.
Resveratrol is a phytoalexin found in grapes, red wine, and berries. Resveratrol has been known to have many beneficial health effects, such as anti-cancer, neuroprotective, anti-inflammatory, and life-prolonging effects. However, relatively little is known about the effects of resveratrol on the regulation of ligand-gated ion channels. We have previously reported that resveratrol regulates subsets of homomeric ligand-gated ion channels such as those of 5-HT3A receptors. The γ-aminobutyric acidC (GABAC) receptor is mainly expressed in retinal bipolar cells and plays an important role in visual processing. In the present study, we examined the effects of resveratrol on the channel activity of homomeric GABAC receptor expressed in Xenopus oocytes injected with cRNA encoding human GABAC ρ subunits. Our data show that the application of GABA elicits an inward peak current (IGABA ) in oocytes that express the GABAC receptor. Resveratrol treatment had no effect on oocytes injected with H2O or with GABAC receptor cRNA. Co-treatment with resveratrol and GABA inhibited IGABA in oocytes with GABAC receptors. The inhibition of IGABA by resveratrol was in a reversible and concentration-dependent manner. The IC50 of resveratrol was 28.9±2.8 µM in oocytes expressing GABAC receptor. The inhibition of IGABA by resveratrol was in voltage-independent and non-competitive manner. These results indicate that resveratrol might regulate GABAC receptor expression and that this regulation might be one of the pharmacological actions of resveratrol on the nervous system.
白藜芦醇是一种存在于葡萄、红酒和浆果中的植物抗毒素。白藜芦醇具有许多有益的健康作用，如抗癌、神经保护、抗炎和延长寿命等。然而，相对较少的是知道白藜芦醇对配体门控离子通道的调节作用。我们之前曾报道过，白藜芦醇调节同源配体门控离子通道的亚群，如 5-羟色胺 3A 受体。γ-氨基丁酸 C（GABAC）受体主要表达在视网膜双极细胞中，在视觉处理中发挥重要作用。在本研究中，我们研究了白藜芦醇对在注射编码人 GABAC ρ亚基的 cRNA 的非洲爪蟾卵母细胞中表达的同源 GABAC 受体通道活性的影响。我们的数据表明，GABA 的应用在表达 GABAC 受体的卵母细胞中引起内向峰电流（IGABA）。用 H2O 或 GABAC 受体 cRNA 注射的卵母细胞用白藜芦醇处理没有影响。白藜芦醇和 GABA 的共同处理抑制了 GABAC 受体卵母细胞中的 IGABA。白藜芦醇对 IGABA 的抑制呈可逆和浓度依赖性方式。在表达 GABAC 受体的卵母细胞中，白藜芦醇的 IC50 为 28.9±2.8 µM。IGABA 被白藜芦醇抑制呈电压非依赖性和非竞争性方式。这些结果表明，白藜芦醇可能调节 GABAC 受体表达，这种调节可能是白藜芦醇对神经系统的药理学作用之一。
