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.
