Differential effect of Rhizoma coptidis and its main alkaloid compound berberine on TNF-α induced NFκB translocation in human keratinocytes

The Chinese medicine Rhizoma coptidis (RC) is well established in the treatment of common dermatological disorders although the mechanism of its' anti-inflammatory effects have previously remained elusive. We stimulated an inflammatory state in human keratinocyte cultures using TNF-α in the presence of RC extract (RCE) and berberine, to identify the dose-dependent anti-inflammatory role of these compounds. Control data demonstrates significant translocation of NFκB into the nucleus after stimulation with TNF-α. This translocation can be inhibited, and hence anti-inflammatory effects inferred, by RCE but not by berberine. We conclude that in dermatological disorders berberine exerts its anti-inflammatory effects by inhibiting signal transduction pathways other than the NFκB dependent pathway, while the RCE complex acts partially by blocking the NFκB dependent pathway. Rhizoma coptidis extract therefore appears to be a potent inhibitor of TNF-α induced inflammation in dermatological conditions.