Abstract P196: Effect of Combined Oral Intake of Ginger Extract and Rice Vinegar on Blood Pressure with 2-kidney,1-clip Renovascular Hypertensive Rats

Abstract

Objective: Ginger is widely used as traditional Asian herbal medicine. Ginger has the same pungent ingredient as chili and vanillyl. We showed that administration of capsaicin to renovascular hypertension (RH) model rats increased endothelial nitric oxide (NO) synthase (eNOS) mRNA expression and NO production, and suppressed blood pressure (BP). Traditionally in Japan, ginger is pickled and eaten. Ginger and vinegar each are supposed to have an effect of suppressing an increase in BP in RH rats. The aim of this study was to investigate the effect. Method: Male Sprague-Dawley rats (6wks) were treated with sham operation (SHAM) as controls or clipping the left renal artery (2K1C) as RH model. After surgery, the rats started receiving a control diet (C) or a diet with 0.08% (w/w) of Ginger Extract (GE) for 6 weeks, and a tap water (W) or a water with 4.5% (v/v) rice vinegar (V). The systolic BP (SBP) was measured by a tail-cuff method every week. At the end of the protocol, the mean arterial BP (MAP) was measured under anesthesia. Then, the aortas were removed for extracting mRNA. mRNA for angiotensin type 2 receptor (AT 2 ) and eNOS was evaluated by real-time RT-PCR. Results: Through the experiment period, SBP was significantly effects in time, model (SHAM vs 2K1C), diet (C vs GE) , timeхanimal ( P <0.001, each) and water (W vs V) ( P <0.05). At the end of the protocol, 2K1C-C+W was higher in SBP than SHAM-C+W (176 ± 6 vs 138 ± 1 mmHg, P <0.05). 2K1C-GE+W showed lower SBP (150 ± 2 mmHg) than -C+W ( P <0.05). SBP was not significantly different in 2K1C-GE+V (149 ± 4mmHg) from in -GE+W. The observations in MAP were similar to those in SBP. AT 2 R mRNA expression showed significant effects in model ( P <0.05) : the mRNA in 2K1C-C+W (0.9 ± 0.2) was significantly greater than in SHAM-C+W (0.4 ± 0.1) ( P <0.05). There were no significant differences among the 2K1Cs: -C+W, -C+V (0.9 ± 0.1), -GE+W (0.8 ± 0.1) and -GE+V (0.9 ± 0.2). eNOS mRNA expression showed significant effects only in diet (CTL vs GE, P <0.05), but not in water and any interactions. Conclusion: Continuous ingestion of GE and V may suppress BP increase in 2K1C, respectively. Simultaneous ingestion of GE and V showed no enhanced effects compared to GE or V solo ingestion in 2K1C. The roles of eNOS and AT 2 R in the mechanism did not become clear in this study.