Anti-inflammatory properties of oolong tea (Camellia sinensis) ethanol extract and epigallocatechin gallate in LPS-induced RAW 264.7 cells

ABSTRACT

Objective:To evaluate the anti-inflammatory activity of oolong tea ethanol extract (OTEE) and epigallocatechin gallate (EGCG) on lipopolysaccharide-induced murine macrophage cell line (RAW 264.7).Methods:A cytotoxic assay using MTS tetrazolium was conducted to find a nontoxic level of OTEE and EGCG toward RAW 264.7 cells.Interleukins (IL-6,IL-1β),tumor necrosis factor-tα (TNF-α),and cyclooxigenase-2 (COX-2) levels were measured by ELISA,and nitric oxide (NO) levels measured by a nitrate/nitrite colorirnetric assay to determine the inhibition activity of OTEE and EGCG.Results:Lipopolysaccharide induction increases NO,COX-2,IL-6,IL-1β,and TNF-α levels compared with the untreated cell (negative control).The positive control,lipopolysaccharide-induced RAW 264.7 without treatments showed the highest level of all pro-inflammatory cytokines and modulators tested in this study.The positive control was used as standard to obtain OTEE and EGCG inhibition activity toward NO,COX-2,IL-6,IL-1 β,and TNF-α.OTEE had a higher inhibition activity toward NO,COX-2,IL-6,and IL-1 β than EGCG;the reverse was seen for TNF-α.However,both OTEE and EGCG suppressed production of NO,COX-2,IL-6,IL-1β,and TNF-α.Conclusions:OTEE and EGCG have the potential for use as anti-inflammatory drugs,which is shown by their ability to reduce the production of NO,COX-2,IL-6,IL-1β,and TNF-α in active macrophages.