Nucleases isolated from Chelidonium majus L. milky sap can induce apoptosis in human cervical carcinoma HeLa cells but not in Chinese Hamster Ovary CHO cells.

Milky sap isolated from Chelidonium majus L. (Greater Celandine) serves as a rich source of various biologically active substances such as alkaloids, flavonoids and phenolic acids. Previous research showed that the activity of Ch. majus milky sap may depend also on the presence of biologically active proteins. The goal of this study was to evaluate the biological effect of two nucleases isolated from Ch. majus milk sap, CMN1 of 20 kDa and CMN2 of 36 kDa, on HeLa and CHO tumour cell lines. Both studied nucleases together with other proteins in the sap of the plant are involved in stress and defence reactions against different pathogens. After 48 h incubation of CMN1 and CMN2 only with HeLa cells, the dependence between the number of apoptotic lesions and the concentration of applied nuclease was observed. The highest proapoptotic activity was induced by 13.3 ng/ml concentration of CMN2 collected in May (62 +/- 3% HeLa cells were apoptotic). Moreover, the proportion of necrotic cells in all concentrations of the nucleases and both cell lines was relatively low (1-8 +/- 0.5%). In summary, results of this study show that purified nucleases CMN1 and CMN2 isolated from Ch. majus milky sap exhibit apoptotic activity in HeLa tumour cell line, but not in CHO cells, without inflammatory reaction.