Goldenseal

The pharmacological action of goldenseal is attributed to the compounds hydrastine and berberine. The majority of clinical studies were not performed with goldenseal, but rather on berberine and hydrastine. Berberine has anti-microbial activity against certain pathogens such enterotoxigenic E. coli and V. cholera. It also induces cell cycle arrest and apoptosis in a variety of cancer cell lines ^{(2) (15) (16)}. One in vitro study found that berberine inhibited the growth of adherent and anoikis resistant MCF-7 and MDA-MB-231 breast cancer cells to a greater extent than doxorubicin ⁽⁴⁾. In one study, berberine alkaloids produced an average of 91% tumor inhibition against 6 malignant brain tumor cell lines both in vivo in mice and in vitro against human brain tumors ⁽⁵⁾. Berberine alkaloids were also shown to have potent macrophage-activating and cytostatic activity against tumor cells. Another study performed in vitro tests on a series of human malignant brain tumor cells and rat brain tumor cells ⁽⁶⁾. Berberine used alone at a dose of 150 mcg/ml had an average cancer cell kill rate of 91%. BCNU (carmustine) had a cell kill rate of 43%. Rats treated with berberine at 10 mg/kg had an 81% kill rate. The combination of both berberine and BCNU had additive effects in killing cancer cells. In an animal study, berberine has been shown to prolong QTc interval and to help prevent ventricular fibrillation after myocardial infarction ⁽¹⁷⁾. The hydrastine component induces constriction of peripheral blood vessels ⁽¹³⁾. While two small clinical trials reported that goldenseal affects CYP2D6 ⁽¹⁸⁾ and CYP3A ⁽¹⁰⁾, another could not confirm such effects ⁽¹⁹⁾.