NMR and radical scavenging activities of patuletin from Urtica urens against aflatoxin B1

In a previous study, we reported six flavonoids isolated from the methanol extract of Urtica urens L. Patuletin, the major component, was found to have powerful anti-inflammatory and antimicrobial activity. We have now investigated whether patuletin also has antioxidant activity and free radical scavenging effects in rats treated with aflatoxin B-1 (AFB(1)). Male Sprague-Dawley rats (60) were assigned to 6 experimental groups including a control group and groups treated for 10 days with patuletin at low dose (7.5 mg/kg b.w) or high dose (10 mg/kg b.w) with or without AFB(1) (2 mg/kg b.w). Blood samples were collected at the end of the experimental period for biochemical analysis. The results showed significant changes typical to aflatoxicosis in rats treated only with AFB(1). Patuletin at the two tested doses caused an increase in glutathione peroxidase (GPx) and superoxide dismutase (SOD); high doses also caused an increase in liver and kidney enzymes, except total bilirubin (TB), which was in the normal value of the control animals. On the other hand, these enzymes were comparable to the controls in rats treated with low doses. Cotreatment of AFB(1) and patuletin resulted in a significant improvement in all parameters tested. We conclude that patuletin possesses an antioxidant activity and free radical scavenging effects in AFB(1)-treated rats that can be observed at a dose as low as 7.5 mg/kg b.w.