Comparative onset of PGE2/COX-2 reduction by flurbiprofen and benzydamine in human bronchialepithelial (BEAS-2B) cells stimulated with polyinosinic:polycytidylic acid (poly I:C)

Introduction

One of the principal triggers of pharyngitis is viral infection, usually by rhinovirus and influenza.1 Inflammation of the pharynx, tonsils and nasopharynx is a result of elevated release of pro-inflammatory mediators, such as prostaglandin E2 (PGE2). Flurbiprofen, a propionic acid derivative family of non-steroidal anti-inflammatory drugs (NSAIDs), is used in the symptomatic relief of pharyngitis due to its ability to inhibit cyclooxygenase-2 (COX-2)-mediated PGE2 production. Benzydamine is an indazole derivative NSAID, which has also been reported to reduce PGE2 production in human gingival fibroblasts.2 In this study, we compared the onset of anti-inflammatory action in flurbiprofen and benzydamine following stimulation of human bronchial epithelial (BEAS-2B) cells with the synthetic double-stranded RNA, poly I:C.

Method

BEAS-2B cells were stimulated with poly I:C (25 μg·ml−1) for 24 μg·ml−1, benzydamine (19, 60 and 190 μg·ml−1) and ibuprofen (100 μg·ml−1) or vehicle (DMSO) for 20 s, 2 min and 5 min. Concentrations were selected based on non-cytotoxic and diluted concentrations from commonly used over the counter (OTC) topical doses (8.75 mg for flurbiprofen) (3 mg for benzydamine). Levels of PGE2 in culture supernatants were determined using PGE2 parameter assay kit (R&D Systems), while protein levels of COX-2 in cell lysates were detected with COX-2 DuoSet ELISA (R&D Systems). Statistical significance of data was determined using one-way ANOVA and Tukey's multiple comparison tests.

Results

Analyses of supernatants revealed that flurbiprofen at all concentrations (μg·ml−1) produced a significant reduction in poly I:C-stimulated PGE2 concentrations from 20 s (P < 0.05), and at 2, and 5 min (P < 0.05) in comparison with stimulated untreated cells. Treatment with benzydamine at the lowest concentration (19 μg·ml−1) had no significant effect on PGE2 at 20 s, at the higher concentrations (60 and 190 μg·ml−1) a weaker but significant (P < 0.05) reduction in PGE2 was found. All flurbiprofen concentrations (μg·ml−1) produced a statistically significant greater reduction in PGE2 at 20 s when compared to benzydamine concentrations (19, 60 and 190 μg·ml−1). All concentrations of benzydamine (19, 60 and 190 μg·ml−1) produced significant (P < 0.05) reductions after 2 and 5 min in comparison with stimulated untreated cells. Flurbiprofen produced a greater reduction in PGE2 at 5 min compared with benzydamine, although the difference was non-significant (P > 0.05). Similarly, flurbiprofen (μg·ml−1) reduced COX-2 protein expression from 20 s (P < 0.05), and after 2 and 5 min (P < 0.05), in comparison with stimulated untreated cells. However, benzydamine at all concentrations (19, 60 and 190 μg·ml−1) produced milder non-significant reductions in COX-2 protein (P > 0.05) across all timepoints with a greater reduction seen at 2 min.

Conclusion

These results suggest that flurbiprofen may be producing faster and more potent reductions in PGE2/COX-2 than benzydamine in human bronchial epithelial cells. In particular, it appears flurbiprofen has a greater anti-inflammatory action compared to benzydamine at the earliest timepoint of 20 s. These observations have significant implications in the use of both drugs to achieve rapid symptomatic relief of pharyngitis.