[Effect of NADH against liver cell line L02 apoptosis induced by UVB irradiation].

OBJECTIVE

To study the molecular mechanism behind the effect of reduced nicotinamide adenine dinucleotide (NADH) against apoptosis of liver cell line L02 induced by ultraviolet B (UVB) exposure.

METHODS

L02 liver cells were exposed to UVB irradiation (200 J/m(2)) followed by a 24-hour culture in the presence or absence of NADH (400 microgram/ml). The degraded fragments of DNA in the cells were observed by agarose electrophoresis, the cell apoptosis rate determined by Annexin/V PI staining and p53, Bax and Bcl-2 proteins expression detected by flow cytometry.

RESULT

NADH not only inhibited the apoptosis induced by UVB irradiation, but also up-regulated the expression of Bcl-2 protein and down-regulated expressions of p53 and Bax proteins (P<0.01). Repair of DNA strand damage was observed in L02 cells during the incubation time after irradiation.

CONCLUSION

NADH significantly inhibits apoptosis induced by UVB irradiation possibly by the mechanism of up-regulating Bcl-2 expression and down-regulating p53 and Bax expressions.