Abstract

Context

Cucumber (Cucumis sativus Linn. [Cucurbitaceae]) is widely known for its purgative, antidiabetic, antioxidant, and anticancer therapeutic potential. However, its effect on gastrointestinal (GI) disease is unrecognised.

Objective

This study investigated the effect of C. sativus fruit extract (CCE) on intestinal chloride secretion, motility, and motor function, and the role of TMEM16A chloride channels.

Materials and methods

CCE extracts were obtained from commercially available cucumber. Active fractions were then purified by HPLC and analysed by high resolution mass spectrometry. The effect of CCE on intestinal chloride secretion was investigated in human colonic T84 cells, ex vivo mouse intestinal tissue using an Ussing chamber, and the two-electrode voltage-clamp technique to record calcium sensitive TMEM16A chloride currents in Xenopus laevis oocytes. In vivo, intestinal motility was investigated using the loperamide-induced C57BL/6 constipation mouse model. Ex vivo contractility of mouse colonic smooth muscles was assessed by isometric force measurements.

Results

CCE increased the short-circuit current (ΔIsc 34.47 ± µA/cm²) and apical membrane chloride conductance (ΔI_Cl 95 ± 8.1 µA/cm²) in intestinal epithelial cells. The effect was dose-dependent, with an EC₅₀ value of 0.06 µg/mL. CCE stimulated the endogenous TMEM16A-induced Cl^- current in Xenopus laevis oocytes. Moreover, CCE increased the contractility of smooth muscle in mouse colonic tissue and enhanced small bowel transit in CCE treated mice compared to loperamide controls. Mass spectrometry suggested a cucurbitacin-like analogue with a mass of 512.07 g/mol underlying the bioactivity of CCE.

Conclusion

A cucurbitacin-like analog present in CCE activates TMEM16A channels, which may have therapeutic potential in cystic fibrosis and intestinal hypodynamic disorders.

中文翻译：

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黄瓜提取物通过刺激肠道 TMEM16A 离子通道引起氯化物分泌

摘要

语境

黄瓜 ( Cucumis sativus Linn. [Cucurbitaceae]) 因其通便、抗糖尿病、抗氧化和抗癌的治疗潜力而广为人知。然而，它对胃肠道 (GI) 疾病的影响尚未得到认可。

客观的

本研究调查了C. sativus果实提取物 (CCE) 对肠道氯化物分泌、运动和运动功能的影响，以及 TMEM16A 氯化物通道的作用。

材料和方法

CCE 提取物是从市售的黄瓜中获得的。然后通过HPLC纯化活性级分并通过高分辨率质谱分析。在人结肠 T84 细胞、离体小鼠肠道组织中使用 Ussing 室研究了 CCE 对肠道氯化物分泌的影响，并使用双电极电压钳技术记录了非洲爪蟾卵母细胞中钙敏感的 TMEM16A 氯化物电流。在体内，使用洛哌丁胺诱导的 C57BL/6 便秘小鼠模型研究了肠道运动。通过等长力测量评估小鼠结肠平滑肌的离体收缩性。

结果

CCE 增加了肠上皮细胞的短路电流 (ΔIsc 34.47 ± µA/cm ² ) 和顶端膜氯化物电导 (ΔI _Cl 95 ± 8.1 µA/cm ² )。效果是剂量依赖性的，EC ₅₀值为 0.06 µg/mL。CCE 刺激非洲爪蟾卵母细胞中内源性 TMEM16A 诱导的 Cl ^-电流。此外，与洛哌丁胺对照相比，CCE 增加了小鼠结肠组织中平滑肌的收缩性并增强了 CCE 治疗小鼠的小肠转运。质谱分析表明具有 512.07 g/mol 质量的葫芦素样类似物是 CCE 生物活性的基础。

结论

CCE 中存在的葫芦素样类似物可激活 TMEM16A 通道，这可能对囊性纤维化和肠道动力不足具有治疗潜力。