The anti-inflammatory potential of berberine in vitro and in vivo

Berberine, an isoquinoline alkaloid, has a wide range of pharmacological effects, including anti-inflammation, yet the exact mechanism is unknown. Because cyclooxygenase-2 (COX-2) plays a key role in prostaglandins (PGs) synthesis, which is elevated in inflammation, we examined whether the anti-inflammatory mechanism of berberine is mediated through COX-2 regulation. In oral cancer cell line OC2 and KB cells, a 12 h berberine treatment (1, 10, and 100 muM) reduced prostaglandin E-2 (PGE(2)) production dose-dependently with or without 12-O-tetradecanoylphorbol-13-acetate (TPA, 10 nM) induction. This berberine induced effect occurred rapidly (3 h) as a result of reduced COX-2 protein, but not enzyme activity. The electrophoretic mobility shift assay revealed that activator protein 1 (AP-1) binding was decreased in oral cancer cells treated with berberine for 2 h. Further analysis showed that berberine inhibited AP-1 binding directly. These anti-inflammatory effects paralleled to the in vivo results where berberine pretreatment of Wistar rat inhibited the production of exudates and PGE(2) in carrageenan induced air pouch. (C) 2003 Elsevier Ireland Ltd. All rights reserved.