Objectives: 

This present study was to investigate the effect of Hibiscus sabdariffa extract (HSE) on the insulin-resistant state, the arterial blood pressure, heart rate (HR) and thoracic elastic property in insulin resistance (IR) rats induced by a high fructose diet (HFD) for 14 weeks.

Materials: 

Male Spraque-Dawley rats were fed with a standard chow diet and distilled water (DW) or a HFD and DW for 14 weeks. The rats were divided into 2 main groups, normal control and IR groups. Then the latter group was subdivided into 2 groups; vehicle IR and IR with the HSE which were simultaneously fed with the HFD and orally given DW or the HSE (500 mg/kg/day) for 4 weeks, respectively. Homeostasis model assessment of insulin resistance index (HOMA –IR) was evaluated. The femoral artery was cannulated for monitoring of arterial blood pressure and HR. The radius and incremental elastic modulus (Einc) of thoracic aorta were examined. The significance of differences between means were analyzed by one-way analysis of variance with Holm-Sidak correction for multiple comparisons.

Results: 

Data in this study demonstrated that the HSE significantly lower HOMA-IR score of the IR rats when compare with the vehicle IR (4.77±0.56 vs 8.56±0.43, p<0.05). In addition, the HSE reduced systolic blood pressure, diastolic blood pressure, mean arterial pressure, and HR of IR rats when compared with the vehicle IR (132.68±1.53 vs 154.44±1.64 mm Hg), (84.10± 1.28 vs 103.79± 1.65), (105.03±1.53 vs 124.85±1.47mm Hg), (350.49±9.91 vs 387.71±9.00 beat/min), respectively; p<0.05), Moreover, the Einc–relative radius curve of the treated with HSE rats was rightward shift more than that of vehicle IR rats.

Conclusions: 

Our study showed that HSE, not only improved the insulin sensitivity, but also decreased vascular stiffness related to reduced blood pressure in insulin resistant rats induced by a HFD.