Berberine, an alkaloid isolated from the plant Berberis aristata, has been
found to inhibit significantly the carcinogenesis induced by 20-methylchola
nthrene (200 mug/0.1 mL/mouse) or N-nitrosodiethylamine (NDEA; 0.02 % NDEA
in distilled water, 2.5 mL/animal by gavage, five days a week for 20 weeks)
in a dose-dependent manner in small animals. Administration of berberine (
0.5, 2.5 or 5.0 mg kg(-1)) could reduce significantly the incidence of tumo
ur in animals after an injection of 20-methylcholanthrene and increased the
ir life span compared with the control. When berberine (10, 25 or 50 mg kg(
-1)) was administered simultaneously with NDEA, the markers of liver injury
(liver weight, gamma -glutamyl transpeptidase activity and glutathione 5-t
ransferase level) were reduced significantly compared with animals treated
with NDEA only, which resulted in all the values being elevated. A similar
decrease was noted in the serum levels of lipid peroxide, bilirubin and glu
tamate pyruvate transaminase. Morphology of liver tissue and levels of mark
er enzymes indicated that berberine offered protection against chemical car
cinogenesis.