Potential drug accumulation and toxicity of addition of the berberine to 5-ASA in DSS-induced chronic relapsing colitis mice.

Experimental colitis was induced by giving mice three cycles of DSS. Each cycle consisted of 2% DSS for five days followed by drinking water for 14 days. The first and last day of DSS treatment were designated as days 0 and 43, respectively. From day 13, experimental mice were treated daily with 5-ASA (200 mg/kg) alone or 5-ASA plus berberine hydrochloride (20 mg/kg) through gavage of 0.2 ml of the respective solution during the 30 days of concomitant DSS-colitis induction. Control mice received water alone. At the end of treatment, mice were killed and the concentrations of 5-ASA (A) and Ac-5-ASA (B) in serum, colon and spleen of colitis mice were measured by LC-MS analysis. Paraffin sections of spleen, lung, liver, and brain (C) were stained with hematoxylin and eosin (H&E). n = 4 mice per treatment group. Scale bar = 50 μm. RePu: Red pulp. WhPu: white pulp. Al: alveolus. InSe: interalveolar septum.CV: central vein. Ne: neuron.