Hibiscus sabdariffa Linnaeus aqueous extracts attenuate the progression of renal injury in 5/6 nephrectomy rats.

Hibiscus sabdariffa Linn. (HS) is a tropical wild plant with antioxidant, antibacterial, antihypertensive, and lipid-lowering properties. In several animal models, HS aqueous extracts reduced the severity of the multi-organ injuries such as hypertension and diabetic nephropathy. One of the multiorgan injuries is chronic kidney disease (CKD), which results from the loss of nephron function. HS was used in a 5/6 nephrectomy (5/6 Nx) rat model to determine if it could attenuate the progression of CKD. HS (250 mg/kg/day) or placebo was orally administered to 5/6 Nx male Sprague-Dawley rats. The Nx+HS group had fewer renal injuries as measured by blood urea nitrogen, serum creatinine, creatinine clearance, and renal pathology when compared with the Nx group. In order to determine which property of HS, either vasodilatory and/or antioxidant, was important in attenuating the progression of CKD, systolic blood pressure (SBP) and serum levels of malondialdehyde (MDA) were assessed. In the Nx+HS group, the SBP and the serum levels of MDA were significantly lower at Week 7. In conclusion, through either antihypertensive and/or antioxidant properties, HS was able to attenuate the progression of renal injury after 5/6 Nx. Hence, HS should be considered as one of the new, promising drugs that can be used to attenuate the progression of CKD.

The safety of Homnawakod herbal formula containing Aristolochia tagala Cham. in Wistar rats.

BACKGROUND: A dried root of Aristolochia tagala Cham. (ATC) is often used in Thai traditional medicine as an antipyretic, anti-inflammatory agent, muscle relaxant, appetite-enhancing agent, and analeptic. Homnawakod, an important herbal recipe, originally contains ATC in its formula, however, some Aristolochia species have been reported to cause nephrotoxicity due to aristolochic acid (AA) and its derivatives, resulting in ATC removal from all formulae. Therefore, this study investigates the chemical profiles of ATC, the original (HNK+ATC) and the present Homnawakod Ayurved Siriraj Herbal Formulary™ (HNK), and investigates whether they could cause nephrotoxicity or aggravate LPS-induced organ injuries in vivo. METHODS: HPLC and LC/MS were used for chemical profile study. Male Wistar rats were randomly divided into groups in which the rats were intragastrically administered distilled water (2 groups), ATC (10 or 30 mg/kg), HNK+ATC (540 or 1,620 mg/kg), or HNK (1,590 mg/kg) for 21 days. A positive control group was administered with single dose 100 mg/kg standard AA-I intragastrically at day 1. Serum creatinine and urea were measured at baseline and at 7, 14 and 21 days of the treatment. On day 22, a model of lipopolysaccharide (LPS)-induced endotoxemia was used. One-way and two-way analyses of variance were performed and a P value of less than 0.05 was considered to be significant. RESULTS: The similarity of the HPLC chromatograms of HNK+ATC and HNK could suggest that the qualities of both formulae are nearly the same in terms of chemical profile. The amount of AA-I found in ATC is 0.24%w/w. All experimental groups exhibited similar levels of serum urea at baseline and 7 and 14 days of the treatment. At 21 days, rats received AA exhibited a significant increase in serum urea, whereas the others did not exhibit such toxicity. On day 22, there were no significant changes in LPS-induced renal and liver dysfunction, or LPS-induced mean arterial pressure (MAP) reduction upon administration of ATC, HNK+ATC, HNK or AA-I. CONCLUSIONS: These results suggest that ATC, HNK+ATC or HNK, at the animal dose equivalent to that used in human, do not cause the acute nephrotoxicity in rats and do not aggravate LPS-induced organ injuries even further.