The Antioxidant Effect of vitamin C on the Paraquat Poisoning

ABSTRACT

BACKGROUND: Paraquat is widely used herbicide. But if it is ingested by accident or by suicidal attempt it causes severe toxicity. And in emergency room, it is a big problem that there is no effective treatment modality for paraquat intoxication. It is reported that the mechanism of toxicity is by oxygen fee radical. And Vitamin C is known as potent antioxidant. This study was designed to evaluate the antioxidant effect of Vitamin C to lipid peroxidaton in paraquat intoxication. METHODS: 24 rats were divided to 6 groups after paraquat injection(20mg/kg), and each groups 4 rats. In 2 control groups we only observed until 6 hours and 24 hours. And Vitamin C of 10 mg per kilogram body weight on the low dose group and 100 mg per kilogram body weight on the high dose group were infected simultaneously. And in 6 hours group, after 6 hours of paraquat and vitamin C injection biochemical levels of malondialdehyde, superoxide dismutase and catalase were measured in liver and lung. And in 24 hours group after 24 hours the same measures were done. The stasistical methods used were ANNOVA and Mann-Whitney test and P-value was 0.05. RESULTS: Malondialdehyde level of high dose Vitamin C group was significantly low compared to that of the control groups in liver tissues after 24 hours(p<0.05). And in lung tissues both low dose and high dose vitamin C groups show significantly low level of malondialdehyde level after 24 hours(p<0.05). On the superoxide dismutase activity, only high dose Vitamin C group shows significantly high level in 24hours both in liver and lung tissues. And the catalase activity is significantly elevated in high dome Vitamin C group after 24hours both in liver and lung tissues. (p<0.05) CONCLUSION: High dose Vitamin C suppresses lipid peroxidation, increases catalase activity and superoxide dismutase activity in paraquat intoxiation. It is thought to by antioxidant elect of vitamin C but it's effect is observed only in 24 hours after intoxication.