OBJECTIVETo investigate the inhibitory effect of matrine on tumor growth in tumor-bearing mice and explore its possible mechanisms of anti-tumor action in vivo.

METHODSHepatocellular carcinoma cells H(22) were subcutaneously injected into BALB/c mice and matrine was administered to the tumor-bearing mice. The kinetics of tumor formation and tumor growth were measured, tumor growth inhibition rate (IR) was calculated, and tumor tissue samples were taken and examined by light and electron microscopy to assess the inhibitory effects of matrine on tumor growth in the mice.

RESULTSMarked inhibitory effect of matrine on the transplanted hepatocellular carcinoma H(22) was observed in the tumor-bearing mice. The inhibitory rates were 62.5% and 60.7% in the groups treated with high and low dosage of matrine, respectively (P < 0.01 vs. control group). The tumor formation was significantly retarded and tumor growth was inhibited in matrine-treated groups compared with those in control mice. Histopathological examination revealed widespread necrosis with massive accumulation of infiltrating lymphocytes and plasmacytes in the tumors. Numerous apoptotic cells and apoptotic bodies were observed in the tumors under the electron microscope.

CONCLUSIONMatrine has marked inhibitory effects on tumor growth in vivo, which is probably related to inhibition of cell division and tumor cell proliferation, directly killing of tumor cells and/or induction of apoptosis and modulation of anti-tumor immune responses.