Protection of chlorophyllin against oxidative damage by inducing HO-1 and NQO1 expression mediated by PI3K/Akt and Nrf2

Green vegetables are thought to have a chemoprotective effect on the basis of epidemiologic evidence. This study investigated whether chlorophyllin (CHL) could induce antioxidant enzymes and confer protection against oxidative damage. The results showed that CHL could induce HO-1 and NQO1 expression in human umbilical vein endothelial cell (HUVEC) in a time-and dose-dependent manner and protect them against hydrogen peroxide caused oxidative damage. The induction of HO-1 and NQO1 by CHL was accompanied with the accumulation of transcription factor Nrf2 in nucleus and the activation of PI3K/Akt signalling pathway. Additionally, the specific inhibitor of PI3K/Akt could obviously decrease not only the induced expression of HO-1 and NQO1 but also the antioxidant effect of CHL. In conclusion, this study proved that CHL exerts antioxidant effect by inducing HO-1 and NQO1 expression mediated by PI3K/Akt and Nrf2. One thinks CHL may have promise to be prophylactic pharmaceuticals without adverse effects.