Anti-inflammatory effect of lycopene on carrageenan-induced paw oedema and hepatic ischaemia-reperfusion in the rat

The regular intake of tomatoes or its products has been associated with a reduced risk of chronic diseases and these effects have been mainly attributed to lycopene. Here, we evaluated the anti-inflammatory properties of lycopene and its protective effects on organ injury in two experimental models of inflammation. In order to study the effects of lycopene in local inflammation, a carrageenan-induced paw oedema model in rats was performed. Lycopene was administered as an acute (1, 10, 25 or 50 mg/kg, intraperitoneally, 15 min before carrageenan injection) and chronic treatment (25 or 50 mg/kg per d, 14 d). Inflammation was assessed by the measurement of paw volume increase after 6 h. Lycopene significantly inhibited paw oedema formation at two doses (25 and 50 mg/kg) in both acute and repeated administration. The effect of lycopene on liver inflammation was evaluated in a liver ischaemia-reperfusion (I/R) model. Rats were subjected to 45 min of ischaemia of three-quarters of the liver followed by 2h of reperfusion. In this model, lycopene was administered daily at two doses (25 and 50mg/kg) during the 14d that preceded the experiments. Repeated administration of lycopene reduced liver injury induced by I/R, as demonstrated by the reduction of the increase in liver injury markers (aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase and gamma-glutamyl transferase) and attenuation of liver tissue lipoperoxidation was evidenced by a decrease in malondialdehyde production. The present results show that lycopene exhibited local anti-inflammatory activity and also attenuated liver injury induced by I/R. We speculate that lycopene administration might be useful in the pharmacological modulation of inflammatory events.