Growth-inhibitory effect of curcumin on Raji cell and its molecular mechanism

OBJECTIVE To study the growth-inhibitory effect of curcumin on lymphoma cell line Raji cell in vitro and its molecular mechanism.METHODS The growth inhibition rate of Raji cells,after being treated with 6.25-50 μmol·L-1 curcumin for 12-48 h,was examined by MTT assay.The apoptosis rate was detected by flow cytometry.The expression of p53 mRNA in Raji cells was checked by RT-PCR.The protein expression levels of bcl-2 and p53 in Raji cell were examined by immunohistochemistry.RESULTS Curcumin inhibited the proliferation of Raji cells in a dose-and time-dependent way with a 24 h IC50 value of 20.40 μmol·L-1.Curcumin(≥12.5 μmol·L-1)induced the apoptosis of Raji cells in a dose-dependent manner.RT-PCR showed that p53 mRNA in Raji cells was down-regulated after being treated with curcumin(25 and 50 μmol·L-1).In addition,immunohistochemistry suggested that curcumin(25 and 50 μmol·L-1)could inhibit the expression of bcl-2 and p53 in Raji cells,and the inhibition was dose-related.CONCLUSION Curcumin could significantly inhibit the growth and induce the apoptosis of Raji cells.The potential anti-tumor mechanism might be related to the inhibition of bcl-2 and p53 expression in Raji cells.