EFFECTS OF INFUSION OF Hibiscus sabdariffa CALYX AND Moringa oleifera LEAF AND THEIR BLENDS ON SOME BIOCHEMICAL PARAMETERS IN RATS

Abstract

Hibiscus sabdariffa and Moringa oleifera have been widely used singly or as mixture in folklore medicine for the treatment of several diseases. The aim of this study is to assess the effect of infusion of Hibiscus sabdariffa calyx, Moringa oleifera leaves and their blends on some biochemical parameters in Wistar rats. Infusion was produced by extracting five hundred (500) grams each of the samples in 2L of boiling water for 10 minutes while the blend was produced by adding specific volume of Moringa of known concentration with Hibiscus and mixed mechanically. The total phenolic content, total flavonoid content and in vitro antioxidant properties as depicted by 2,2-diphenyl 1,picryl hydrazyl (DPPH), 2,2 azimo-bis)3- ethylbenzothiazoline6-sulphonic acid(ABTS), radical scavenging ability, nitric oxide(NO) scavenging ability, ferric reducing antioxidant power (FRAP), Fe2+ chelation and inhibition of lipid peroxidation of the infusions as well as their blends were determined. The effect of the infusion on Arginase activity was also determined in vitro. The acute and sub-acute toxicity tests were carried out on rats to ascertain their safety dosage. Effect(s) of the infusion and their blends on testes, reproductive hormones and cholinergic enzymes of rats of both sexes were also assessed. Furthermore, the phenolic constituents of Moringa oleifera leaf and Hibiscus sabdariffa calyx were characterized using high performance liquid chromatography coupled to diode array detector (HPLC-DAD). The infusion were rich in antioxidants and inhibited Arginase activity with the blends having higher antioxidant property in majority of the parameters tested in vitro. HPLC-DAD characterization of the infusion revealed the presence of different phenolic acids and flavonoids. Results from acute toxicity test in which a single dose of 5,000mg/kg of Hibiscus sabdariffa and 3,000mg/kg of Moringa oleifera were orally administered to rats did not produce any mortality within 24hours observation. Also, in the sub-acute tests the infusion at low, moderate and high dosage (250, 750 and 1,500mg/kg body weight) orally administered to rats for 28days showed varying effects on renal and hepatic function markers. The highest dosage (1,500mg/kg) evoked a significant (p<0.05) increase in urea, uric acid and creatinine concentration in both male and female rats. Blends of Moringa (MO) and Hibiscus (HS) in ratio 1:1, 1:5 and 5:1 MO/HS were administered at 250mg/kg and 1,500mg/kg dosage, the 1,500mg/kg dosage had adverse effect on the kidney and also on the liver of female rats. Also, 250mg/kg dosage compared to the single infusion. Results from the 250mg/kg administration of the blends showed nephroprotective effect of the blends and no adverse effect on the liver. The blends also reduced some of the toxic effect of the highest dosage (1,500mg/kg) on the liver by not reducing antioxidant enzymes activity and not increasing liver function marker. These blends also increased male reproductive hormones (LH, FSH and testosterone) concentration, increased nitric oxide level, inhibited arginase and acetylcholinesterase activities in vivo and reduced MDA levels in the testis. Findings from these studies revealed that infusion of Hibiscus sabdariffa, beyond 250mg/kg had adverse effect on the kidney but Moringa oleifera infusion up to 750mg/kg did not have toxic effect on these organs. However, their blends did not adversely affect the kidney, liver and testis rather they mitigate some of the toxic effect of Hibiscus at 1, 500mg/kg and may possibly act as a pro-fertility agent.