[Protective effects of ligustrazine against photoreceptor cell injury induced by N-methyl-N-nitrosourea and its mechanism].

Aim: To study the protective effect of ligustrazine against photoreceptor cell injury induced by N-methyl-N-nitrosourea (MNU) in Sprague-Dawley (SD) rats.

Methods: Ligustrazine injections of different doses were injected intraperitoneally into 47-day female SD rats once a day and a single intraperitoneal injection of MNU 60 mg x kg(-1) was given to 50-day rats. At different intervals after MNU treatment,the animals were sacrificed. The apoptotic index of photoreceptor cells was calculated by TUNEL labeling at 24 h following MNU treatment; peripheral retinal damage was evaluated based on retinal thickness at the d 7 after MNU treatment, and the expression of c-jun and c-fos genes was detected by RT-PCR technique.

Results: Ligustrazine injection could remarkably increase total thickness of peripheral retina and decrease apoptotic index of photoreceptor cells induced by MNU in a dose-dependent manner. Compared with MNU-treated rats, the gene expression of c-jun and c-fos was time-dependently down-regulated in ligustrazine-treated group.

Conclusion: Ligustrazine injection partially protects against MNU-induced retinal damage by down-modulating the expression of c-jun and c-fos genes to inhibit apoptosis of photoreceptor cells.