Effect of green tea extract and epigallocatechin gallate on bovine neutrophil function (140.10)

Abstract Neutrophils play an important role as the first line of defense in protecting hosts from microbial invasion, but the delayed migration and prolonged presence of neutrophils can result in sustained inflammation. The aim of this study was to determine effect of green tea extract (GT) and its major anti-inflammatory component, epigallocatechin gallate (EG), on bovine neutrophils in order to decipher possible clinical use of GT and EG to alleviate inflammation. Effects of GT and EG on degranulation, oxidative burst, CD11b expression, and neutrophil apoptosis were investigated at concentrations from 1 to 100 μg/mL (GT) or μM (EG) in different assay conditions. Concurrent, pre, and post treatment of GT and EG with saline or standard stimulant (calcium ionophore or phorbol myristate acetate) significantly reduced degranulation and superoxide production compared to control (no GT/EG). Significant reduction in CD11b expression was observed in EG treated samples, but not all GT samples had similar effect. GT and EG at concentrations of 50 and 100 μg/mL (GT) or μM (EG) triggered neutrophil apoptosis determined by Annex-V cell surface binding and 7 amino-actinoycin intracellular staining. The in vitro reduction of cattle neutrophil function suggests potential of GT and EG to be used in clinical applications as support to anti-inflammatory therapy.