Protective Effects of Extracts of Vernonia amygdalina, Hibiscus sabdariffa and Vitamin C against Radiation-induced Liver Damage in Rats

Abstract

The radioprotective efficacy of methanolic extracts of leaves of Vernonia amygdalina (VA) and Hibiscus sabdariffa (HS), and vitamin C (VIT C) against gamma radiation (4 Gy) induced liver damage was studied in male Wistar albino rats. VIT C was administered at a dose of 250 mg/kg body weight, while VA and HS were administered at doses; 200, 400 and 800-mg/kg body weight, orally for 4 weeks prior to radiation and 5 weeks after irradiation. The rats were sacrificed at 24 hours and 5 weeks after irradiation. Treatment with VIT C and VA (800 mg/kg) significantly (p < 0.05) decreased the gamma radiation-induced increases in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities at 24 hours after irradiation, whereas, HS (400 mg/kg) significantly (p < 0.05) decreased the serum ALT activity only. Similarly, treatment with VIT C and VA (800 mg/kg) significantly (p < 0.05) decreased the serum conjugated bilirubin levels by 56% and 29%, respectively at 24 hours. Furthermore, VIT C, VA and HS significantly (p < 0.05) decreased the levels of serum lipid peroxidation (LPO) and increased the hepatic superoxide dismutase (SOD) activities at 24 hours. Treatment for 5 weeks after irradiation with VITC, VA and HS significantly (p < 0.05) decreased the levels of unconjugated bilirubin, while VIT C and VA alone decreased the levels of conjugated bilirubin. Furthermore, treatment with VA (400 and 800 mg/kg) decreased the serum ALT activities by 25% and 34%, respectively, at 5 weeks after irradiation. Similarly, alkaline phosphatase and LPO levels were significantly (p < 0.05) attenuated following treatment with VIT C and VA (400 and 800 mg/kg) at 5 weeks after irradiation. In addition, treatment with VIT C, VA (800 mg/kg) and HS (400 and 800 mg/kg) significantly (p < 0.05) elevated the levels of reduced glutathione (GSH) by 61%, 56%, 41% and 44%, respectively, at 5 weeks. Similar elevation of antioxidant enzymes; SOD, glutathione-s-transferase and catalase were obtained in animals treated with VIT C and extracts at 5 weeks. Taken together, the results suggest that the extracts of VA and HS, and VIT C could increase the antioxidant defense systems and may probably protect animals from radiation-induced liver damage.

<em>Vernonia amygdalina</em> leaf extract and alpha-tocopherol alleviated gamma radiation-induced haematological and biochemical changes in rats

“…This finding contradicts the findings of Sharma et al (2001) and Yammani et al (2002) who reported hypo-albuminaemia due to albuminuria in the rat following single dose TBI although Yammani and his colleagues had irradiated rats with 9.5 Gy of X-rays as a single dose. This contradiction in the result of the present study may be due to the fact that a lower radiation dose of 2.0 Gy was used, apart from the fact that gamma rays and not X-rays were used as in the study of Yammani et al The result is, however in agreement with the findings of Adaramoye et al (2008), who used gamma rays at a dose of 5.0 Gy and observed an elevated the RSA of the irradiated rats. Of importance was the finding that pretreatment with MEVA and TOCO significantly reduced the elevated level of RSA to a level comparable to the control value.…”

“…Apart from synthetic antioxidants, studies have shown that commonly used medicinal plants, are also good sources of antioxidants that offer radioprotection in untried models. Examples include Aegele marmelos, Hibiscus sabdariffa, and Vernonia amygdalina (Jagetia et al, 2004;Adaramoye et al, 2008;Owoeye et al, 2010). Vernonia amygdalina, commonly called "bitter leaf' is a popular African vegetable whose health benefits have been reported (Igile et al, 1994).…”

Effect of Gamma Ray on Reactive Oxygen Species at Experimental Animals

“…Lipid peroxidation is considered to be a critical event of ionizing radiation effect. Most of the toxic effects of ionizing radiation are due to generation of reactive oxygen species (ROS) by radiolysis of water which triggers formation of several reactive intermediates [2].…”

The Efficacy of Karkadeh Tea in Controlling Post-Prandial Blood Glucose Levels

“…Treatment with vitamin C and Hibiscus sabdariffa (400 mg kg −1 ) significantly decreased serum ALT activity (p<0.05). In addition, treatment with vitamin C and Hibiscus sabdariffa (400 and 800 mg kg −1 ) significantly (p<0.05) elevated the levels of reduced glutathione by 41 and 44%, respectively, at 5 weeks [2] . In other fields of research, pre-treatment with an aqueous extract of Hibiscus sabdariffa has been shown to result in significantly (p<0.01) less hepatotoxicity and to protect rats against cadmium-induced liver, prostate and testis lipoperoxidation [6] .…”

“…These authors, however, found that triglycerides and cholesterol levels were not significantly affected [3] . Extracts of Hibiscus sabdariffa in combination with vitamin C have been found to increase the antioxidant defence systems of rats and reduce the incidence of organ damage [2] . Treatment with vitamin C and Hibiscus sabdariffa (400 mg kg −1 ) significantly decreased serum ALT activity (p<0.05).…”