Effects of oral administration of berberine on distribution and metabolism of 2-aminofluorene in Sprague-Dawley rats.

The effects of berberine on the in vivo N-acetylation and metabolism of 2-aminofluorene (2-AF) in bladder, blood, colon, kidney, liver, feces and urine samples and brain tissues (cerebrum, cerebellum and pineal gland) of male Sprague-Dawley rats were investigated. Major metabolites, such as 1-OH-2-AAF, 3-OH-2-AAF, 8-OH-2-AAF and 9-OH-2-AAF were found in bladder tissues, 1-OH-2-AAF, 5-OH-2-AAF and 8-OH-2-AAF were found in blood samples, 1-OH-2-AAF, 3-OH-2-AAF, 5-OH-2-AAF, 8-OH-2-AAF and 9-OH-2-AAF were found in colon tissues, 1-OH-2-AAF, 3-OH-2-AAF and 9-OH-2-AAF were found in kidney tissues, 1-OH-2-AAF, 3-OH-2-AAF and 8-OH-2-AAF were found in liver tissues, 1-OH-2-AAF, 3-OH-2-AAF, 5-OH-2-AAF, 7-OH-2-AAF, 8-OH-2-AA and 9-OH-2-AAF were found in feces samples and 1-OH-2-AAF, 3-OH-2-AAF, 5-OH-2-AAF, 7-OH-2-AAF, 8-OH-2-AA and 9-OH-2-AAF were also found in urine samples, 1-OH-2-AAF, 3-OH-2-AAF and 8-OH-2-AAF were found in cerebrum tissues, 1-OH-2-AAF, 3-OH-2-AAF and 7-OH-2-AAF were found in cerebellum tissues. In the control group, however, only 2-AF and 2-AAF were found in pineal gland after rats had been orally treated with 2-AF (50 mg/kg) for 24 h. Pre-treatment of male rats with berberine (40 mg/kg) 24 h prior to the administration of 2-AF (50 mg/kg), as well as the co-administration of berberine and 2-AF led to a decrease in the amounts of 3-OH-2-AAF and an increase in the amounts of 8-OH-2-AAF in bladder tissues. In blood samples, there were significant decreases of 2-AF, 2-AAF, 1-OH-2-AAF and 8-OH-2-AAF, after rats were pre-treated with berberine for 24 h before the addition of 2-AF. However, co-administration of berberine and 2-AF led to an increase in the amounts of 5-OH-2-AAF. In colon tissues, there were significant decreases of 2-AF, 2-AAF, 1-OH-2-AAF and 8-OH-2-AAF in colon samples after rats were treated with berberine for 24 h before the addition of 2-AF. 2-AF, 1-OH-2-AAF, 3-OH-2-AAF and 9-OH-2-AAF levels were significantly different between control and the group treated with berberine and 2-AF at the same time. In kidney tissues, significant decreases of 2-AF and 2-AAF and of 3-OH-2-AAF were observed after rats were treated with both compounds separately and simultaneously. However, 24 h berberine pre-treatment followed by addition of 2-AF led to significant increase of 9-IH-2-AAF. In liver tissues, there were significant decreases of 2-AAF and 1-OH-2-AAF, after co-administration of berberine and 2-AF. The amounts of 2-AAF, 1-OH-2-AAF and 3-OH-2-AAF were significantly different between the control and the group pretreated with berberine 24 h before the addition of 2-AF. In the feces samples, there were significant decreases of 2-AAF, 3-OH-2-AAF, 7-OH-2-AAF, 8-OH-2-AAF and 9-OH-2-AAF after co-administration of berberine and 2-AF. However, the berberine pre-treatment followed by addition of 2-AF led to a significant increase of 2-AF, 2-AAF and 1-OH-2-AAF levels. In urine samples, there were significant differences of 2-AF, 2-AAF, 1-OH-2-AAF, 3-OH-2-AAF, 5-OH-2-AAF, 8-OH-2-AAF and 9-OH-2-AAF after the co-treatment. However, berberine treatment followed by 2-AF led to significant differences in 1-OH-2-AAF and 5-OH-2-AAF levels. In the cerebrum samples, there were significant differences in 1-OH-2-AAF and 8-OH-2-AAF after both berberine co-treatment and pre-treatment. In cerebellum samples, there were also significant differences in the 1-OH-2-AAF and 3-OH-2-AAF levels after both co- and pretreatment. In pineal gland samples, there were significant differences in 2-AAF levels after co-treatment with berberine and 2-AF and 1-OH-2-AAF was also found in both groups. However, berberine pre-treatment followed by 2-AF led to different levels of 2-AF and 2-AAF, but not of 3-OH-2-AAF.