Nkosi C Z, Opoku A R, Terblanche S E
Department of Biochemistry and Microbiology, University of Zululand, Private Bag X1001, KwaDlangezwa, 3886, South Africa.
Phytother Res. 2006 Nov;20(11):935-40. doi: 10.1002/ptr.1977.
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 (CCl(4))-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 CCl(4) 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 CCl(4) 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 CCl(4) 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 CCl(4) intoxication. It is therefore apparent that pumpkin seed protein isolate has components that have antiperoxidative properties.
研究了南瓜籽（西葫芦）分离蛋白对低蛋白喂养的Sprague-Dawley大鼠（褐家鼠）四氯化碳（CCl₄）诱导的急性肝损伤中肝脏匀浆过氧化氢酶（CA）、超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSHpx）和总抗氧化能力（TAC）以及葡萄糖-6-磷酸酶（G6Pase）的血浆活性水平，以及肝脏匀浆和肝脏微粒体部分脂质过氧化（LPO-丙二醛-MDA）水平的影响。将一组维持低蛋白饮食5天的雄性Sprague-Dawley大鼠分为三个亚组。两个亚组注射四氯化碳，另一组注射等量的橄榄油。四氯化碳中毒两小时后，两个亚组中的一个给予南瓜籽分离蛋白，然后换成20%的南瓜籽分离蛋白饮食。另外两组大鼠在整个研究期间维持低蛋白饮食。来自不同亚组的大鼠在各自治疗后24、48和72小时处死。在低蛋白饮食5天后，所有酶的活性水平以及抗氧化水平均显著低于正常均衡饮食组。然而，低蛋白饮食导致脂质过氧化水平显著升高。在所有研究变量方面，四氯化碳中毒大鼠的反应与低蛋白饮食组大鼠相似。四氯化碳中毒后给予南瓜籽分离蛋白导致所有研究变量水平显著升高，但脂质过氧化水平显著降低。从本研究结果得出结论，给予南瓜籽分离蛋白可有效减轻与蛋白质营养不良和四氯化碳中毒相关的有害影响。因此，很明显南瓜籽分离蛋白具有具有抗过氧化特性的成分。
