Influence of berberine on T-cell mediated immunity.

The protoberberine alkaloid berberine is isolated as a main alkaloid from the roots and bark of Berberis vulgaris. Berberine strongly inhibited in vitro the proliferative response of mouse spleen cells to T-dependent mitogens concanavalin A (Con A) and phytochemagglutinin (PHA). Spleen cells obtained from berberine-treated mice (10 mg/kg/3 days) expressed enhanced proliferative response to both mitogens. Berberine was applied to mice at different intervals before or after the induction of adjuvant arthritis (AIA) and Candida albicans (C. albicans) infection. The application of the alkaloid to new born mice (5 days after birth at a dose of 5 mg/kg/3 days) did not change the course of AIA and C. albicans infection. Its application at three 10 day intervals (5 mg/kg), starting from the 5 day after birth increased the joint inflammation in AIA. The host resistance to C. albicans infection was not affected, while the delayed type hypersensitivity (DTH)-reaction against the pathogen was enhanced. The alkaloid inhibited the development of AIA when applied after its onset (10 mg/kg from day +3 to +12 day). Berberine treatment during the ongoing infection did not influence its outcome (from +2 to +10 day).