[Vinegar processing attenuates toxicity on IEC-6 cells caused by chloroform extraction of Daphne genkwa]

Abstract

To screen the toxic polar fractions of Daphne genkwa, compare the toxicity of D. genkwa on crypts epithelial cells IEC-6 before and after vinegar processing, and preliminarily investigate the mechanism of D. genkwa vinegar processing on toxicity reducing. The proliferation of IEC-6 cells was observed by MTT. The levels of superoxide dismutase (SOD), malondialdehyde (MDA), glutathione (GSH), lactate dehydrogenase (LDH), as well as the enzyme activity of Na⁺-K⁺-ATPase and Ca²⁺-Mg²⁺-ATPase were determined in IEC-6 cells to evaluate the oxidative damages degree of IEC-6 cells. The apoptosis and cell cycle were analyzed by Flow Cytometry. The results showed that the dichloromethane extraction was the toxic polar fraction of D. genkwa, and after vinegar processing, the toxicity of dichloromethane fraction was significantly reduced (P<0.01). As compared with the blank control group, the dichloromethane fraction of D. genkwa can obviously decrease the levels of SOD, Na⁺-K⁺-ATPase, Ca²⁺-Mg²⁺-ATPase (P<0.01) and content of GSH, but increase the level of LDH and MDA in cell supernatant (P<0.01). Besides, it obviously increased the early and late apoptotic rate of IEC-6 cells, obviously decreased the proportion of G₁stage cells, increased the ratio of S stage cells and M stage cells (P<0.01). After vinegar processing, as compared with D. genkwa groups of various doses, it can significantly increase the levels of SOD, Na⁺-K⁺-ATPase, Ca²⁺-Mg²⁺-ATPase (P<0.01) and content of GSH, decrease the level of LDH, MDA(P<0.01), significantly decrease the early and late apoptosis rate of IEC-6 cells (P<0.01), increase the proportion of G₁stage cells, and decrease the ratio of S stage cells and M stage cells (P<0.01). Vinegar processing can reduce the toxicity of dichloromethane fraction of D. genkwa, and its mechanism may be associated with improving the activity of antioxidant enzymes and permeability in IEC-6 cells, and decreasing the oxidative damage.

Keywords: Daphne genkwa; apoptosis; cell cycle; oxidative injury; vinegar processing.