Protective effect of Aronia melanocarpa fruit juice pretreatment in a model of carbon tetrachloride-induced hepatotoxicity in rats

The main active ingredients of Aronia melanocarpa fruit juice (AMFJ) are phenolic substances, mainly flavonoids from the anthocyanin subclass. AIM: The aim of the present study was to investigate the effect of AMFJ applied as pretreatment in a model of carbon tetrachloride (CCl4)-induced hepatotoxicity in rats. MATERIAL AND METHODS: AMFJ was given orally to rats for 2 days at doses of 5, 10 and 20 ml/kg either alone or as pretreatment before the oral application of CCl4 (0.2 ml/kg, 2 days). The plasma activities of aspartate transaminase (AST) and alanine transaminase (ALT) were measured as markers of the liver cell damage. The levels of malondialdehyde (MDA), a lipid peroxidation marker, were determined in rat liver and plasma. RESULTS: Administration of CCl4 caused an elevation of plasma AST and ALT activities. It also induced an elevation of MDA levels in rat liver and plasma. AMFJ applied alone in the tested doses did not cause any significant changes in the measured enzyme activities and in MDA levels. AMFJ applied as pretreatment prevented the CCl4-induced increase of AST and ALT activities, and also prevented the elevation of plasma and liver MDA levels. CONCLUSIONS: AMFJ showed a protective effect in a model of CCl4-induced hepatotoxicity in rats. This effect might be due to the antioxidant activity of its active ingredients.     

Influence of DL-alpha-tocopherol acetate on indomethacin-induced gastric mucosal injury in rats

1 There is an increasing body of evidence supporting the hypothesis that antioxidants are able to reduce gastric mucosal damage induced by stressors of different origin. The aim of the present study was to investigate the influence of dl-alpha-tocopherol acetate (TA) on indomethacin-induced gastric mucosal injury in rats and a possible role for an anti-oxidative mechanism in the response. 2 TA (25, 50 and 100 mg kg(-1)) was applied intraperitoneally as a pretreatment 1 h before the subcutaneous administration of indomethacin (30 mg kg(-1)). 3 TA reduced the area of indomethacin-induced gastric ulcers, the effect being significant (P < 0.05) at the highest dose of 100 mg kg(-1). 4 Histopathological examination of rat stomach samples demonstrated that TA caused an increase in gastric mucus production and a reduction of the severity of mucosal lesions. 5 The three doses of TA prevented indomethacin-induced elevation of plasma and mucosal malondialdehyde (MDA) levels, which in TA-pretreated rats were not significantly different from the control values. Neither indomethacin treatment nor TA pretreatment had a significant influence on the gastric mucosal levels of reduced glutathione or oxidized glutathione. 6 Our results suggest that the gastroprotective effect of TA is likely to be due to increased mucus production and interference with oxidative stress development as evidenced by the decreased plasma and gastric mucosal MDA.