Role of selective antioxidants and anti-inflammatory drug in preventing udder cell damage in vitro.

摘要

The current study aimed to investigate the role of melatonin, beta -carotene, selenium and hydrocortisone in protecting a primary mammary cell line as a model of mastitis from the deleterious effects of reactive oxygen species (ROS) secreted from activated neutrophils in vitro. Different concentrations of melatonin (0.5, 5, 50 and 500 micro M), beta -carotene (1, 10 and 100 micro M), selenium (0.001, 0.01 and 0.1 micro M) and hydrocortisone (0.1, 1 and 10 micro M) were added separately in triplicates to primary mammary epithelial cell lines prepared from active mammary tissue of female buffaloes coincubated with activated buffalo neutrophils (5x106/well). Mammary cell damage was evaluated by measuring lactate dehydrogenase (LDH), malondialdehyde (MDA) and nitric oxide (NO) concentrations in culture media as indicative of ROS, and by morphological observations of neutrophils after acridine orange staining. Activated neutrophils damaged the mammary epithelial cell line as demonstrated by an increase in LDH, MDA and NO concentrations in control mammary cells that did not receive any treatments. Meanwhile, mammary epithelial cells treated with melatonin, beta -carotene, selenium and hydrocortisone secreted low concentrations of LDH, MDA and NO. Neutrophils treated with antioxidants or hydrocortisone did not show much damage compared with non-treated control cells. These results suggest that ROS such as superoxides, hydrogen peroxide, hydroxyl radical and nitric oxide released by activated neutrophils cause damage to mammary epithelial cells indicated by increased concentrations of LDH, MDA and NO, and this deleterious effect could be resolved by the use of antioxidants such as melatonin, beta -carotene and selenium or by the use of antiinflammatory compounds such as hydrocortisone.