Effects of saw palmetto extract on the vanilloid receptor TRPV1.

IF 1.5 4区医学 Q3 UROLOGY & NEPHROLOGY LUTS: Lower Urinary Tract Symptoms Pub Date : 2022-03-01 Epub Date: 2021-10-21 DOI:10.1111/luts.12413

Shizuo Yamada, Yoshihisa Kato

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引用次数: 4

Abstract

Objective: Transient receptor potential vanilloid subtype 1 (TRPV1) may play a significant role in the pathophysiology of the bladder. The present study investigated the effects of the herbal product, saw palmetto extract (SPE) on TRPV1-mediated Ca²⁺ influx and specific [³ H]resiniferatoxin ([³ H]RTX) binding to TRPV1 in HEK293 cells expressing TRPV1 (HEK293VR11 cells).

Methods: Ca²⁺ influx induced by and the direct binding activity of TRPV1 were measured using a method with Fura 2-AM, a cytoplasmic calcium indicator, and a radioligand binding assay using a [³ H]RTX, respectively.

Results: SPE did not markedly affect Ca²⁺ influx in HEK293VR11 cells; however, it significantly inhibited capsaicin-induced increases in Ca²⁺ influx in these cells. The specific binding of [³ H]RTX in HEK293VR11 cells was saturable with K_d value of 120 ± 7 pM and B_max of 1.07 ± 0.10 fmol/mg protein, and was inhibited by low concentrations of non-labeled RTX with K_i of 60.1 ± 7.6 nM. These results confirmed the pharmacological specificity of specific binding sites of [³ H]RTX to TRPV1 in HEK293VR11 cells. SPE inhibited the specific binding of [³ H]RTX in a concentration-dependent manner, with K_i of 24.2 ± 1.4 μg/mL.

Conclusions: The present study demonstrated for the first time, that SPE inhibited capsaicin-induced Ca²⁺ influx with binding to TRPV1 in HEL293VR11 cells. These results will contribute to a more detailed understanding of the pharmacological effects of SPE on urinary dysfunction.

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锯棕榈提取物对香草素受体TRPV1的影响。

目的:瞬时受体电位香草样蛋白亚型1 (TRPV1)可能在膀胱病理生理中起重要作用。本研究研究了草药产品锯棕榈提取物(SPE)对TRPV1介导的Ca2+内流和特异性[3h]树脂干扰素([3h]RTX)在表达TRPV1的HEK293细胞(HEK293VR11细胞)中与TRPV1结合的影响。方法:分别采用胞质钙指示剂Fura 2-AM法和[3 H]RTX法测定TRPV1诱导的Ca2+内流和TRPV1的直接结合活性。结果:SPE对HEK293VR11细胞Ca2+内流无显著影响;然而，它显著抑制了辣椒素诱导的这些细胞中Ca2+内流的增加。[3 H]RTX在HEK293VR11细胞中的特异性结合达到饱和状态，Kd值为120±7 pM, Bmax为1.07±0.10 fmol/mg蛋白，低浓度无标记RTX (Ki为60.1±7.6 nM)可抑制[3 H]RTX的特异性结合。这些结果证实了HEK293VR11细胞中[3h]RTX对TRPV1特异性结合位点的药理学特异性。SPE对[3 H]RTX的特异性结合呈浓度依赖性，Ki值为24.2±1.4 μg/mL。结论:本研究首次证实了SPE在HEL293VR11细胞中通过与TRPV1结合抑制辣椒素诱导的Ca2+内流。这些结果将有助于更详细地了解SPE对泌尿功能障碍的药理作用。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

LUTS: Lower Urinary Tract Symptoms UROLOGY & NEPHROLOGY-

CiteScore

3.00

自引率

7.70%

发文量

审稿时长

>12 weeks

期刊介绍： LUTS is designed for the timely communication of peer-reviewed studies which provides new clinical and basic science information to physicians and researchers in the field of neurourology, urodynamics and urogynecology. Contributions are reviewed and selected by a group of distinguished referees from around the world, some of whom constitute the journal''s Editorial Board. The journal covers both basic and clinical research on lower urinary tract dysfunctions (LUTD), such as overactive bladder (OAB), detrusor underactivity, benign prostatic hyperplasia (BPH), bladder outlet obstruction (BOO), urinary incontinence, pelvic organ prolapse (POP), painful bladder syndrome (PBS), as well as on other relevant conditions. Case reports are published only if new findings are provided. LUTS is an official journal of the Japanese Continence Society, the Korean Continence Society, and the Taiwanese Continence Society. Submission of papers from all countries are welcome. LUTS has been accepted into Science Citation Index Expanded (SCIE) with a 2011 Impact Factor.