BACKGROUND: Retinitis pigmentosa (RP) is a non-inflammatory, bilaterally progressive, retinal degeneration characterized by loss of photoreceptor cells via an apoptotic mechanism, and it eventually leads to blindness.Research shows that the traditional Chinese medicines of Astragalus has great prospect on blocking the progression of RP disease.OBJECTIVE: To observe the protective effect of Astragalus on N-methylN-nitrosourea (MNU)-induced retinal damage in Sprague-Dawley (SD) rats and provide the optimal treatment for RP in humans.DESIGN: Randomized controlled experiment.SETTING: School of Pharmaceutical Sciences, Xinxiang Medical College.MATERIALS :The experiment was completed in Pharmacological Laboratory of Zhongshan Ophthalmic Centre, Sun Yat-sen University between March to December 2004. Totally 114 female SD rats were purchased from the Animal Center of Zhongshan Medical College, Sun Yat-sen University.MNU was purchased from Sigma Company of America. Astragalus injection was purchased from Chengdu Diao Jiuhong Pharmaceutical Factory (Batch No. Z99060535, 2 mL/ampoule, main ingredient: Astragalus).METHODS: Among 114rats, 30 were for morphometric analysis of retinal layers, 30 were for detection of apoptosis and 54 were for detection of NF-κB p65 activity. All of them were randomly divided into different groups and each group had 6 rats. Astragalus at doses of 2.5, 5 and 10 g/kg were injected intraperitoneally into 47-day rats once a day. Meanwhile, a single intraperitoneal injection of 60 mg/kg MNU was given to 50-day rats in model and Astragalus groups. At different intervals after MNU treatment,the animals were sacrificed. Retinal damage was evaluated based on retinal thickness, the apoptotic index of the photoreceptor cells was detected by TUNEL labeling and the DNA-binding activity of NF-κB p65 was analyzed according to transcription factor assay kit.MAIN OUTCOME MEASURES: Comparison of retinal thickness, apoptotic index and the activity of nuclear NF-κB p65.RESULTS: Totally 114 rats entered the result analysis. Pretreatment with Astragalus could dose-dependently suppress MNU-induced photoreceptor cell loss and decreased the apoptotic index. Astragalus at dose of 10 g/kg also time-dependently up-regulated the activity of nuclear NF-κB p65.However, protective effect of Astragalus on MNU-induced central retinal damage was not found.CONCLUSION: Astragalus partially protects against MNU-induced retinal damage by up-modulating the activity of nuclear NF-κB p65 to inhibit apoptosis of photoreceptor cells in a dose-dependent manner.

AIM:To investigate the effects of nodosin extracted from Chinese traditional medicine on the pro-liferation of HepG2 cells cultured in vitro and to detect the protein expression of Bcl-2 and Bax in HepG2 cells.METH-ODS:HepG2 cells were treated with different concentrations (1.25, 2.5, 5, 10 and 20 μmol/L) of nodosin for 24 h. The morphological changes of HepG2 cells were observed under inverted microscope.The inhibitory rates of HepG2 cell growth were detected by MTT assay.The apoptotic rates and the protein expression of Bcl-2 and Bax were analyzed by flow cytometry.RESULTS:Shrunken and suspended HepG2 cells increased with the increases in the concentrations of nodo-sin.The apoptotic rates and the expression of Bax increased with the increases in the doses of nodosin, while the expression of Bcl-2 decreased.CONCLUSION:Nodosin inhibits the growth of HepG2 cells in a dose-dependent manner.The inhibi-tion of HepG2 cell growth is induced by decreasing Bcl-2 and increasing Bax, thus promoting cell apoptosis.