Bidirectional function of shenghe powder on repair of radiation-induced DNA damage in glioma and astrocyte

The study assessed the effect of Chinese herbs of Shenghe Powder (SHP) on the repair capacity of gamma-radiation-induced DNA damage in rat glioma cells (C6) compared with normal human astrocytes (NHA). C6 and NHA Cells treated with SHP and irradiated with 2Gy of gamma radiation. Cells growth inhibition were analysed by MTT assay, DNA damage and repair were evaluated using phosphorylated histone H2AX (γH2AX) at the appointed time. Apoptosis was observed by flow cytometry, and the expression of DNA-dependent protein kinase (DNA-PK) and surviving proteins were assessed by Western blot analysis. SHP depressed the radiation-induced DNA double-strand break and enhanced the DNA repair capacity in NHA, which correlated with promotion of DNA-PK phosphorylation. In contrast, SHP enhanced radiosensitivity of C6 cells, the pre-treatment with SHP resulted in reduced numbers of γH2AX foci in irradiated C6 cells, and decreased the expression of DNA-PK and survivn(P