The purpose of this study was to investigate the potential antitumor efficacy of conjugated linoleic acid-paclitaxel （CLA-PTX） on B16-F10 melanoma cell line in vitro and in vivo. The in vitro cytotoxicity, apoptosis and cell cycle of CLA-PTX were investigated. The in vitro cellular uptake of CLA-PTX in B16-F10 cells was also analyzed. The antitumor activity of CLA-PTX was also evaluated in B16-F10 tumor-bearing C57BL6/N mice in vivo. The in vitro cytotoxicity results showed that the IC50 of the CLA-PTX is （4.25±0.43） μM, compared with that of （6.70±0.80） μM in PTX treatment group （P〈0.01）. CLA-PTX increased the percentage of total apoptotic cells compared with that of control and PTX treatment groups （P〈0.01）. Compared with untreated cells, CLA-PTX arrested cell cycle progression at the S phase, whereas PTX caused accumulation of cell at GE-M phase both along with the reduction of the cellular fraction arrested at the G1 phase. The amount of cellular uptake of CLA-PTX was significantly higher than that of PTX （P〈0.01）. The in vivo antitumor activity of CLA-PTX was significantly higher than that of control and PTX treatment groups （P〈0.01 or P〈0.05）. In conclusion, our study demonstrated that CLA-PTX has significant antitumor activity in B 16-F 10 cell line.
Considering the results of our previous research that conjugated linoleic acid mixture-paclitaxel （CLA-mixture-PTX） possesses anti-tumor activity against melanoma and brain glioma, the purpose of this study was to investigate the potential anti-tumor efficacy of cis-9, trans- 1 1-conjugated linoleic acid-paclitaxel （c9, tl 1-CLA-PTX） and trans- 1 O, cis- 12-conjugated linoleic acid-paclitaxel （tl0, c12-CLA-PTX） on MCF-7 breast cancer cell line in vitro and in vivo. The in vitro cytotoxicity, apoptosis induction effect and cell cycle arresting effect of c9, t1 1-CLA-PTX and t10, c12-CLA-PTX were investigated. The in vitro cellular uptake of c9, tl 1-CLA-PTX and tl0, cl2-CLA-PTX in MCF-7 cells were also analyzed. Besides, the anti-tumor activity of c9, tl 1-CLA-PTX and tl0, cl2-CLA-PTX was evaluated in MCF-7 tumor bearing nude mice in vivo. The in vitro cytotoxicity results showed that the value of ICs0 of the tl 0, c l2-CLA-PTX is （0.17±0.02） μM, compared with that of （1.08±0.15） μM in CLA-mixture-PTX and （6.50±1.20） μM in c9, tl 1-CLA-PTX treatment group （P〈0.01）. Both tl0, cl2-CLA-PTX and c9, t l 1-CLA-PTX increased the percentage of total apoptotic cells compared with that of control （P〈0.01）. And the rank of apoptosis induction efficacy was t 10, c 12-CLA-PTX〉CLA-mixture-PTX〉c9, t 11-CLA-PTX （P〈0.01）. Compared with untreated cells, the tl0, c12-CLA-PTX and c9, tl 1-CLA-PTX arrested cell cycle progression at the S and G2-M phase. The amount of cellular uptake of t 10, c 12-CLA-PTX was significantly higher than that of CLA-mixture-PTX （P〈0.01）, which was significantly higher than that of c9, t1 1-CLA-PTX （P〈0.01）. The rank of in vivo anti-tumor activity was tl0, c12-CLA-PTX〉CLA-mixture-PTX〉 c9, t1 1-CLA-PTX （P〈0.01）. In conclusion, our study demonstrated that both tl0, cl2-CLA-PTX and c9, tl 1-CLA-PTX has significant anti-tumor activity in MCF-7 cell line. And while c9, tl 1-CLA-PTX showed weaker inhibitory effect than CLA-mixture-PTX, str
