Antioxidative effects of pumpkin seed (Cucurbita pepo) protein isolate in CCl4-Induced liver injury in low-protein fed rats
Article first published online: 14 AUG 2006
Copyright © 2006 John Wiley & Sons, Ltd.
Volume 20, Issue 11, pages 935–940, November 2006
How to Cite
Nkosi, C. Z., Opoku, A. R. and Terblanche, S. E. (2006), Antioxidative effects of pumpkin seed (Cucurbita pepo) protein isolate in CCl4-Induced liver injury in low-protein fed rats. Phytother. Res., 20: 935–940. doi: 10.1002/ptr.1977
- Issue published online: 20 OCT 2006
- Article first published online: 14 AUG 2006
- Manuscript Accepted: 25 APR 2006
- Manuscript Received: 15 JUN 2005
- Research Committee of the University of Zululand
- Medical Research Council of South Africa
- South African Sugar Association
- pumpkin seed protein isolate;
- Cucurbita pepo;
- carbon tetrachloride-induced liver injury;
- low-protein fed rats;
- plasma enzymes;
- total antioxidant capacity;
- lipid peroxidation
The effects of pumpkin seed (Cucurbita pepo) protein isolate on the plasma activity levels of catalase (CA), superoxide dismutase (SOD), glutathione peroxidase (GSHpx) and total antioxidant capacity (TAC) as well as glucose-6-phosphatase (G6Pase) in liver homogenates and lipid peroxidation (LPO-malondialdehyde-MDA) levels in liver homogenates and liver microsomal fractions against carbon tetrachloride (CCl4)-induced acute liver injury in low-protein fed Sprague-Dawley rats (Rattus norvegicus) were investigated.
A group of male Sprague-Dawley rats maintained on a low-protein diet for 5 days were divided into three subgroups. Two subgroups were injected with carbon tetrachloride and the other group with an equivalent amount of olive oil. Two hours after CCl4 intoxication one of the two subgroups was administered with pumpkin seed protein isolate and thereafter switched onto a 20% pumpkin seed protein isolate diet. The other two groups of rats were maintained on the low-protein diet for the duration of the investigation. Groups of rats from the different subgroups were killed at 24, 48 and 72 h after their respective treatments. After 5 days on the low-protein diet the activity levels of all the enzymes as well as antioxidant levels were significantly lower than their counterparts on a normal balanced diet. However, a low-protein diet resulted in significantly increased levels of lipid peroxidation. The CCl4 intoxicated rats responded in a similar way, regarding all the variables investigated, to their counterparts on a low-protein diet. The administration of pumpkin seed protein isolate after CCl4 intoxication resulted in significantly increased levels of all the variables investigated, with the exception of the lipid peroxidation levels which were significantly decreased. From the results of the present study it is concluded that pumpkin seed protein isolate administration was effective in alleviating the detrimental effects associated with protein malnutrition and CCl4 intoxication. It is therefore apparent that pumpkin seed protein isolate has components that have antiperoxidative properties. Copyright © 2006 John Wiley & Sons, Ltd.