Abstract:Sheep placenta was used as the raw material to extract proteins and peptides. The protein content and MTT tumor inhibitory activity were used as the evaluation indexes to screen the extraction and fractions of sheep placenta with anti-tumor activity. The results showed that the stirred extraction method mixed phosphate buffer solution could be used to prepare sheep placenta extracts with inhibitory activity against a colon cancer cell lines. The specific conditions were as follows: mixed phosphate buffer solution (containing 0.15 mol/L NaCl solution, 50 mmol/L conventional PBS solution, and 0.5~1 mmol/L phenylmethylsulfonyl fluoride) at pH value 7.4, extraction temperature of 4~10 ℃, and extraction for 2 h. The total extract yield and the protein content were 37.91 and 55.62%, respectively. The results of antitumor activity showed that the inhibition rate was 56.88 and 53.07% in HT-29 and HCT-116 cells, respectively, when the concentration of the extract was 2 mg/mL. The total extract was isolated and purified using a Sephadex-G-25 gel column chromatography to obtain F2 and F3 fractions with good inhibitory activity against HT-29 and HCT-116 cells; the IC50 of F2 was 0.328 and 0.183 mg/mL, respectively, and the IC50 of F3 was 0.213 and 0.095 mg/mL, respectively. In conclusion, the active fractions obtained from the gel column chromatography of the mixed phosphate extract of sheep placenta had good inhibitory activity against colon cancer cell lines. The results provide theoretical and technical support for the effective development and comprehensive utilization of sheep placenta waste.
