ABSTRACT
Aims: The toxicity of ethanol whole plant extract of Euphorbia lateriflora was assessed in Albino Wistar rats. Methodology: The LD50 was at single dose of 5000 mg/kg body weight, the sub-acute dosage of the extract was administered orally at 250 and 500 mg/kg b.w.t twice daily for 7 days and the effect of the extract on liver, kidney, and haematological parameters was assessed and recorded during these periods. Results: The result of the oral acute toxicity study at single high dose of 5000 mg/kg/bwt shows that the LD50 of the extract is greater than 5000 mg/kg/bwt. After 7 days of oral administration, 500 mg/kg/bwt of the extract caused a significant (p<0.05) decrease in the packed cell volume. At 500 mg/kg/bwt, the extract caused a significant (p<0.05) increase in ALP, total protein and albumin and decrease in serum electrolytes (Na+, k+ and Cl-). Histopathological analysis revealed the expansion of fibrous spaces in the liver and thickening of the glomerular basement of the kidney in the group fed with 500 mg/kg/b.w.t of extracts. Conclusion: In conclusion, the dose and time-dependent selective organ toxicity effect of this extract suggested that the extract might be relatively unsafe for consumption at especially high concentrations.
ABSTRACT
Aims: Hibiscus sabdariffa is a medicinal plant species that is consumed for its health benefits in Africa, therefore this study investigated the antioxidant properties of Hibiscus polyphenolic rich extract (HPE), prepared from Hibiscus sabdariffa. Place and Duration of Study: School of Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool, United Kingdom, between June 2009 and December 2010. Methodology: The antioxidant assays evaluated the scavenging abilities of HPE: Firstly against superoxide ions generated during the xanthine oxidase mediated breakdown of xanthine to uric acid. Secondly against ABTS (2,2-azino-bis-(3-ethylbenzthiazoline 6-sulfonic acid)) radical cation generated by filtering a solution of ABTS through manganese dioxide powder and potassium persulphate. Finally metal chelation ability of HPE against Iron ions (Fe2+) induced oxidative damage in cultured Jurkat-T cells was also assessed. Results: The results showed that 1.0% and 2.5% (v/v) diethyl ether extract of HPE significantly inhibited superoxide ions by 42.35 and 100.00% respectively. The extract also inhibited uric acid production, which suggest that components of HPE inhibit xanthine oxidase activity. In addition, it was found that HPE scavenge ABTS radical cations in dose dependent manner. HPE inhibited Fe2+-mediated lipid peroxidation in cultured Jurkat-T cells supplemented with 0.5 mg/ml and 1.0 mg/ml of HPE by 19.67% and 31.69% respectively, metal chelation ability was identified as a potential mechanism behind this observed reduction. Conclusions: HPE is rich in different phenolic compounds; therefore strong antioxidant potential of HPE observed in this study may be related to their polyphenolic constituents. This study demonstrated that Hibiscus sabdariffa is an efficient antioxidant plant species in vitro and may be beneficial in reducing oxidative damage to lipid and thus prevent or reduce the development and progression of free radical mediated diseases.