Berberine is an isoquinoline alkaloid found in various plants, including Berberis vulgaris (barberry), Coptis chinensis (Chinese goldthread), and Hydrastis canadensis (goldenseal). It has a bright yellow color and is used as a dye in addition to its medicinal properties. Berberine has been shown to have numerous pharmacological activities, including antimicrobial, anti-inflammatory, antidiabetic, and antineoplastic effects. It works by inhibiting various enzymes and signaling pathways, leading to changes in gene expression and cellular metabolism. It has been investigated for its potential therapeutic use in conditions such as diabetes, cardiovascular disease, and cancer.