Glycine reduces cadmium-induced alterations in the viability and activation of macrophage U937 cells

This study investigates the effect of glycine on cadmium-induced alterations on the viability and activation of the cell line U-937. In this experiment, U-937 cells were pre-treated with 16 microM cadmium (as cadmium chloride). These cadmium-treated cells were later incubated with or without glycine (1-16 microM). After 72 h, it was revealed that glycine significantly (P<0.05) reduced the tendency of cadmium to reduce the viability of the cells. U-937 cells were also treated with phorbol, 12-myristate, 13-acetate to enhance their transition to the macrophage form. Thereafter, the cells were treated with cadmium with or without glycine (1-16 microM). Twenty-four hours later, the supernatants of each cell culture were assessed for the production of tumour necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6), interleukin 1 (IL-1), nitric oxide (NO), and catalase activity as indices of the activation of macrophages. The results show that glycine significantly (P<0.05) reduced the cadmium-induced production of all the markers of the activation of macrophages in a concentration-dependent manner. The findings support the immense antioxidant role of glycine.