Protective effects of Radix Pseudostellariae extract against retinal laser injury.

BACKGROUND This study aimed to analyze the protective effects of a saponin extract from Radix Pseudostellariae (RP) on retinal laser injury based on a retinal photocoagulation model. METHODS Fifty-eight rabbits were randomly divided into three groups: Group A (saponin extract orally), Group B (physiological saline), and Group C (control). The animals were sacrificed 1 day, 7 days, 14 days, and 30 days after photocoagulation and lesions were evaluated with fundus photography, light microscopy, and electron microscopy. Superoxide dismutase (SOD) and malondialdehyde (MDA) levels were measured, and expression levels of c-fos and Bax genes were also determined. RESULTS The lesion sizes in Group A were smaller than in Group B. The levels of SOD in Group B were significantly lower than in groups A and C (P<0.001) at all time points. The MDA levels were significantly lower than in groups B and C (P<0.001) at the 1 month point, while the apoptosis rate of Group A was significantly lower than that of Group B at all time points. The expression levels of the c-fos gene in Group B were significantly higher than that in groups A and C, and expression levels of the Bax gene in Group A were significantly lower than that in groups B and C. CONCLUSION The saponin extract of RP can inhibit oxidative stress, downregulate the levels of c-fos and Bax gene expression, and inhibit apoptosis in the retina after photocoagulation.