The Antitumor Activity Of Sanchinoside Pn4 And Its Effect In Induction Of Apoptosis On HL-60 Cells

OBJECTIVE: To investigate the antitumor activity of Sanchinoside Pn4 invitro and in vivo, the apoptosis induced by Pn4 on human premyo leukemia cell HL-60 and its acute toxicity in mice. METHODS:The cytotoxicity of Pn4 on human tumour cell lines were determined by MTT assay and the results were expressed as IC50 values; The inhibitory effect of Pn4 on the growth of tumor was observed with the models of transplanted sarcoma 180 (S180) and hepatoma 22 (H22) in mice by the means of peros (po) or by intraperitoneal (ip) and the results were expressed as inhibitory rate of tumor growth. The apoptosis was identified by means of morphology observation, DNA break mark and flow cytometry. The cell cycle distribution and apoptosis quantity determination were determined by flow cytometry. The expression of Bcl-2/Bax was examined by immunohistochemistry assay. The acute toxicity of Pn4 was observed on mice. RESULTS: The results showed that the average of IC₅₀ values of Pn4 on K562, COC1, BGC-823, MCF-7 and HL-60 cell lines were 22.65 , 18.27±12.07, 36.20±2.85, 27.12±7.19, 28.03±0.37μg/ml, respectively; Pn4 could obviously inhibit the growth of S180 and H22 in mice and showed a dose-effect relationship. The effect of Pn4 administrated by ip was better than that of po. There was no obvious difference between the administration of pre-inoculability and post-inoculability administrated by po. Pn4 could arrest the HL-60 cells at G0/G1 phase, and induce HL-60 cells to apoptosis. It was also showed that Pn4 could down-regulate the expressing of Bcl-2 andup-regulate the expressing of Bax. The all mice tested for acute toxicity were not dead at dose of lOg/kg (po) and 2g/kg (ip), respectively. CONCLUSION: Pn4 exhibited significant antitumor activity in vitro and in vivo. Pn4 was capable of arresting the cell cycle at G0/G1 phase,and could induced HL-60 cells apoptosis. The antitumor activity of Pn4 may be related to its cell cycle arrest and induction apoptosis, and apoptosis occurring was associated with the expression of Bcl-2 down-regulation and Bax up-regulation. At the same time, The acute toxicity of Pn4 was not observed.