Institute of Physiology and Pathophysiology, Paracelsus Medical University Salzburg, 5020 Salzburg, Austria.
J Ethnopharmacol. 2013 Oct 28;150(1):85-94. doi: 10.1016/j.jep.2013.08.013. Epub 2013 Aug 24.
Traditional Mongolian medicine (TMM) uses preparations from herbs as one form of medication for the treatment of a diversity of diseases including diabetes mellitus (DM). We evaluated the effect of extracts from the plant Leonurus sibiricus L. (LS), used in TMM to treat typical symptoms of type 2 DM, on insulin secretion, electrophysiological properties, intracellular calcium concentration and cell proliferation of INS-1E insulinoma cells under standard cell culture conditions (SCC; 11.1mM glucose).
Insulin secretion was measured by ELISA, electrical properties were assessed by whole cell patch clamping, intracellular calcium concentration (Cai) by Fluo-4 time lapse imaging, insulin receptor expression was verified by RT-PCR and cell proliferation assessed by CellTiter-Glo® cell viability assay.
Insulin released from INS-1E cells into the culture medium over 24h was significantly increased in presence of 500 mg/L aqueous LS extract (LS OWE) as well as methanolic LS extract (LS MeOH/H2O) but not in the presence of the butanol-soluble extract (LS MeOH/BuOH). Acute application of LS OWE resulted in a depolarization of the cell membrane potential paralleled by an initial increase and subsequent decline and silencing of action potential frequency, by KATP channel inhibition, persisting depolarization and an increase in Cai. The electrophysiological effects were comparable to those of 100 μM tolbutamide, which, however failed to elevate insulin secretion under SCC. Furthermore all LS extracts stimulated INS-1E cell proliferation.
The finding that extracts from Leonurus sibiricus L. enhance insulin secretion and/or foster cell proliferation may provide possible explanations for the underlying therapeutic principles in the empirical use of LS-containing formulations in DM and DM-related disorders as applied in TMM.
传统蒙医药（TMM）使用草药制剂作为治疗包括糖尿病（DM）在内的多种疾病的药物之一。我们评估了用于 TMM 治疗 2 型 DM 典型症状的植物益母草（LS）提取物对 INS-1E 胰岛细胞瘤细胞在标准细胞培养条件（SCC；11.1mM 葡萄糖）下胰岛素分泌、电生理特性、细胞内钙浓度和细胞增殖的影响。
通过 ELISA 测量胰岛素分泌，通过全细胞膜片钳评估电生理特性，通过 Fluo-4 延时成像测量细胞内钙浓度（Cai），通过 RT-PCR 验证胰岛素受体表达，通过 CellTiter-Glo®细胞活力测定评估细胞增殖。
在 500mg/L 水 LS 提取物（LS OWE）和甲醇 LS 提取物（LS MeOH/H2O）存在下，INS-1E 细胞分泌到培养基中的胰岛素在 24 小时内显著增加，但在丁醇可溶提取物（LS MeOH/BuOH）存在下则没有。LS OWE 的急性应用导致细胞膜电位去极化，伴随着初始增加和随后的下降以及动作电位频率的沉默，这是由 KATP 通道抑制、持续去极化和 Cai 增加引起的。电生理效应与 100μM 甲苯磺丁脲相当，然而，在 SCC 下，它未能增加胰岛素分泌。此外，所有 LS 提取物均刺激 INS-1E 细胞增殖。
益母草提取物增强胰岛素分泌和/或促进细胞增殖的发现可能为 LS 含制剂在 DM 和 DM 相关疾病中的经验应用提供了在 TMM 中应用的潜在治疗原理的解释。
