Effects of oral co-administration of captopril and Hibiscus sabdariffa on blood pressure and histological changes on 2K1C animal model

The Two Kidney One Clip (2K1C) animal models are commonly used during preclinical studies related to renovascular hypertension [1]. Hibiscus sabdariffa (HS) aqueous extract has angiotensin converting enzyme (ACE) inhibitory activities and is often co-administered with captopril (CAP) during management of hypertension therapy. [2] In this study, we compared the effect of CAP plus HS aqueous extract co-administration to CAP and HS administration alone on blood pressure and histological changes in clipped kidney of 2K1C animal models. The 2K1C Sprague dawley rats were randomly divided into 4 groups i.e. negative control (no treatment), positive control (4.5 mg captopril/200 g BW), HS alone (30 mg/200 g BW), and coadministration group (30/200 g BW HS and 4.5 mg/200 g BW CAP). The CAP and HS extract were given by oral gavage for two weeks.

All treatment groups showed significant blood pressure reduction compared to negative control. There is no significant difference (p > 0.05) between measured blood pressure of rats in CAP alone group and CAP plus HS co-administration group. The size of clipped kidney was significantly reduced compared to unclipped kidney. Clipped kidney of 2K1C groups showed the symptom of nephritis.Treatment with HS alone and co-administration of CAP plus HS could not stop the mononuclear infiltration and necrosis progress of clipped kidney. Kidney’s specimen of CAP alone showed a normal tubules profiles however the abnormal accumulation of mononuclear cells was similar with the 2K1C groups. Co-administration of CAP plus HS didn’t give both additional blood pressure reduction and significant effect on histological changes in 2K1C animal models, therefore co-administration of H. sabdariffa L. aqueous extract with captopril should be reconsidered.

• References

• 1 Chelko SP, Schmiedt CW, Lewis TH, Lewis SJ, Robertson TP. A novel vascular clip design for the reliable induction of 2-kidney, 1-clip hypertension in the rat. J Appl Physiol 2012; 112 (03) : 362-366
• 2 Hopkins AL, Lamm MG, Funk JL, Ritenbaugh C. Hibiscus sabdariffa L. in the treatment of hypertension and hyperlipidemia: a comprehensive review of animal and human studies. Fitoterapia 2013; 85: 84-94