Abstract: Objective:To investigate the protective effect of Qijudihuang Pill on the retinal structures of the glaucoma model rats, and to clarify its mechanism. Methods:Fifty SD rats were randomly divided into blank control group, model group,and low, medium, and high doses of Qijudihuang Pill groups(n=10). The chronic glaucoma rat models were established by using cauterization on episcleral veins in each group except blank control group. The rats in low, medium, and high doses of Qijudihuang Pill groups were given 1,2, and 4 g·kg^-1 Qijudihuang Pill by gavage, while the rats in blank control group and model group were given the same volume of saline, 1 time per day. After 12 weeks of administration, the morphological changes in ocular tissue were analyzed by HE staining. The apoptosis of retinal ganglion cells was detected by TUNEL staining. The expression levels of Bcl-2, Bax,and caspase-3 mRNA in the retina tissue of the rats in various groups were determined by RT-PCR.The expression levels of Bcl-2, Bax, and caspase-3 proteins in the retina tissue of the rats in various groups were determined by immunohistochemistry. Results:Compared with blank control group, the retinal nerve fibers in model group were irregularly arranged, the interfibrillar substance was edematous, the cell layer was vacuolated, and the number of retinal ganglion cells was reduced significantly.Compared with model group, the number of retinal ganglion cells of the rats in high dose of Qijudihuang Pill group was increased; the retinal nerve fiber cells in the eyes of the rats in low dose of Qijudihuang Pill group and medium dose of Qijudihuang Pill group were arranged neatly, and the morphology of ganglion cells were normal.Compared with model group, the apoptotic indexes of retinal ganglion cells in low, medium, and high doses of Qijudihuang Pill groups were decreased significantly(P<0.05); the mRNA and protein expression levels of Bcl-2 were increased significantly(P<0.05), while the mRNA and protein expression levels of Bax and caspase-3 were decreased significantly(P<0.05). Conclusion:Qijudihuang Pill can protect the retina of glaucoma rats by regulating the mRNA and protein expressions of Bcl-2, Bax, and caspase-3 and inhibiting the apoptosis of retinal ganglion cells.

Key words: Qijudihuang Pill, glaucoma, rats,SD, apoptotic index