Phytoantibiotics for the treatment of intestinal infections. 1. Used for fluorescent staining of heparin sodium in mast cells. 2. An alkaloid with weak antibiotic properties, a substrate of bacterial multidrug-resistant efflux pumps (MDReffluxpumps) Chemicalbook. The antimicrobial activity of berberine can be enhanced by the MDR inhibitor 5´-methoxyhydnocarpin (5´-MHC). Berberine regulates the expression of Pgp gene in liver cancer cells.