Effects of saw palmetto extract on the vanilloid receptor TRPV1

Beneficial effects of saw palmetto (Serenoa repens) fruit extract on the urinary symptoms of healthy Japanese adults with possible lower urinary tract symptoms: A randomized, double-blind, placebo-controlled study

Saw palmetto extract (SPE) is the most commonly used supplement for the treatment of lower urinary tract symptoms (LUTS), but most evidence is for those with LUTS, and little data is verifying its effectiveness for those who do not have the disease but are troubled by symptoms. The purpose of this study was to examine the effect of SPE on the improvement of urinary frequency problems that present stress due to urinary urgency in daily life, among healthy Japanese adults aged ≥50 years who are not diagnosed with benign prostatic hyperplasia or overactive bladder. They were randomly assigned to the SPE group or placebo group (34 participants per group) using a computerized random number generator. Each participant was instructed to take one capsule containing SPE (320 mg) or placebo every day for 12 weeks. Subjective symptoms were assessed using the overactive bladder questionnaire, and the score of symptom bother by frequent urination during the daytime hours was set as the primary outcome. The other outcomes were subjective urinary symptoms and urinary frequencies. The final efficacy analysis dataset was per protocol set, and 33 participants in each group were analyzed. After SPE intervention for 12 weeks, the score of symptom bother by frequent urination during the daytime hours was significantly improved and the daytime frequency of urination assessed using the urinary log was significantly decreased. The consumption of SPE improved urinary frequency-related quality of life such as bother of urinary symptoms in healthy Japanese adults (UMIN000045334).

Progress in the development of TRPV1 small-molecule antagonists: Novel Strategies for pain management

Transient receptor potential vanilloid 1 (TRPV1) channels are widely distributed in sensory nerve endings, the central nervous system, and other tissues, functioning as ion channel proteins responsive to thermal pain and chemical stimuli. In recent years, the TRPV1 receptor has garnered significant interest as a potential therapeutic approach for various pain-related disorders, particularly TRPV1 antagonists. The present review offers a comprehensive, systematic exploration of both first- and second-generation TRPV1 antagonists in the context of pain management. Antagonists are categorized and explicated according to their structural characteristics. Detailed examination of binding modes, structural features, and pharmacological activities, alongside a critical appraisal of the advantages and limitations inherent to typical compounds within each structural category, are undertaken. Detailed discussions of the binding modes, structural features, pharmacological activities, advantages, and limitations of typical compounds within each structural category offer valuable insights and guidance for the future research and development of safer, more effective, and more targeted TRPV1 antagonists.

Establishment of a Cell Model for Dynamic Monitoring of Intracellular Calcium Concentration and High-Throughput Screening of P2Y2 Regulators

P2Y receptors are G-protein-coupled receptors (GPCRs) for extracellular nucleotides. The P2Y2 receptor subtype is expressed in a variety of cell types and plays an important role in physiological and pathophysiological processes such as inflammatory responses and neuropathic pain. Based on this, the P2Y2 has been identified as an important drug target. The specificity of current P2Y2 receptor modulators is relatively poor, and currently, specific and efficient P2Y2 receptor modulators and efficient screening strategies are lacking. In this study, a cell model based on calcium-activated chloride channels (CaCCs) was established that can detect changes in intracellular calcium concentrations and can be used to high-throughput screen for P2Y2 receptor-specific regulators. This screening strategy is suitable for screening of most G-protein-coupled receptor regulators that mediate increases in intracellular calcium signals. The cell model consists of three components that include the endogenously expressed P2Y2 receptor protein, the exogenously expressed calcium-activated chloride channel Anoctamin-1 (Ano1), and a yellow fluorescent protein mutant expressed within the cell that is highly sensitive to iodine ions. This model will allow for high-throughput screening of GPCR regulators that mediate increased intracellular calcium signaling using the calcium-activated transport of iodide ions by Ano1. We verified the ability of the model to detect intracellular calcium ion concentration using fluorescence quenching kinetic experiments by applying existing P2Y2 agonists and inhibitors to validate the screening function of the model, and we also evaluated the performance of the model in the context of high-throughput screening studies. The experimental results revealed that the model could sensitively detect intracellular calcium ion concentration changes and that the model was accurate in regard to detecting P2Y2 modulators. The resultant value of the Z-factor was 0.69, thus indicating that the model possesses good sensitivity and specificity.

Beneficial Effects of Saw Palmetto Fruit Extract on Urinary Symptoms in Japanese Female Subjects by a Multicenter, Randomized, Double-Blind, Placebo-Controlled Study

Saw palmetto berry extract (SPE) is the most commonly consumed supplement by men with benign prostatic hyperplasia (BPH). The oral administration of SPE was previously shown to significantly attenuate urodynamic symptoms in the hyperactive bladders of female rats by increasing bladder capacity and prolonging the micturition interval. The amelioration of urodynamic symptoms by SPE may be partly attributed to its binding to muscarinic receptors in the urinary bladder and its inhibition of vanilloid receptors on afferent nerves. Therefore, SPE may be pharmacologically effective at mitigating lower urinary tract symptoms (LUTS) in women. The efficacy and safety of a 12-week treatment with SPE in adult women with urinary symptoms were examined herein. The daytime frequency score in the core lower urinary symptom score (CLSS) questionnaire was significantly lower in women with LUTS treated with SPE for 12 weeks than in the placebo group. A subgroup analysis revealed that SPE alleviated the symptoms of daytime frequency (CLSS Q1) and nocturia (CLSS Q2) in a subset of subjects with a CLSS Q5 score of 1 or higher. The daytime frequency of urination in overactive bladder symptom score (OABSS) Q1 was also significantly improved by the SPE treatment. In conclusion, the present study is the first to demonstrate the potential of SPE to mitigate LUTS in adult women.