Modulation of nitric oxide synthase activity by Burantashi (pausinystalia yohimbe) extract in Wistar rats

Abstract

Introduction: Yohimbine-containing herbs (pausinystalia yohimbe, ‘Burantashi’) are traditionally used as aphrodisiacs and may alter nitric oxide synthase (NOS) pathways. NOS is essential for nitric oxide (NO) generation, which facilitates penile smooth muscle relaxation and vasodilation. Aim and objectives: To examine the impact of sildenafil and the methanolic stem-bark extract of pausinystalia yohimbe (Burantashi) on NOS mRNA expression in male Wistar rats. The goals were to: (1) give graded extract dosages for 28 days; (2) measure NOS gene expression using semi-quantitative densitometry and RT-PCR; and (3) compare expression between groups. Materials and methods: For 28 days, 25 adult male Wistar rats (n = 5 per group) were given either Burantashi extract (50, 100, or 200 mg/kg), sildenafil (5 mg/kg), or distilled water (control). Following euthanasia, NOS PCR was performed using agarose gel electrophoresis, and blood/tissue RNA was collected and reverse-transcribed. Tukey’s post hoc test was used to analyse the results of a one-way analysis of variance (ANOVA). Results: Comparing the Burantashi-treated groups to the control, semi-quantitative densitometry showed dose-dependent elevation of NOS mRNA; sildenafil induced a strong upregulation. One-way ANOVA F(4,20) p < 0.001; Tukey’s post hoc: sildenafil and 200 mg significantly higher versus control, p < 0.01) showed the following representative (reconstructed) fold-change in NOS expression (mean ± standard error of mean) normalised to control (1.00): control 1.00 ± 0.05, sildenafil 2.10 ± 0.12, Burantashi 50 mg/kg 1.25 ± 0.08, 100 mg/kg 1.78 ± 0.09, and 200 mg/kg 2.45 ± 0.11). Conclusion: In male Wistar rats, burantashi methanolic extract dose-dependently increases NOS gene expression, indicating that increased NO production is a likely explanation for its traditional aphrodisiac usage. The source data showed no concurrent rise in serum testosterone. Quantifying functional NO generation, hemodynamic outcomes, and safety will require additional effort.