Antisecretory effects of berberine with morphine, clonidine, L-phenylephrine, yohimbine or neostigmine in pig jejunum.

The effects of berberine alone or in combination with morphine, clonidine, L-phenylephrine or yohimbine were compared in Escherichia coli heat-stable enterotoxin (ST)-exposed ligated jejunal loops in 2 week old pigs. In addition, net water and electrolyte fluxes in normal jejunal loops were measured in the presence of neostigmine, morphine, clonidine, L-phenylephrine or yohimbine alone or in combination with berberine. Berberine, morphine, clonidine and L-phenylephrine each reduced the net secretion of water and electrolytes induced by ST (P less than 0.05). A significant enhancement of antisecretory effect was observed only with the combination of berberine and L-phenylephrine. Yohimbine or neostigmine augmented the net loss of water and electrolytes produced by ST. Yohimbine did not block the antisecretory action of berberine. In normal jejunum, there was no significant difference in water and ion absorption between adrenergic or opiate agonists alone and their combination with berberine. Neostigmine reversed absorption to net secretion in normal jejunum and this effect was significantly reduced by berberine. The anti-secretory action of berberine appears similar to that of alpha 2-adrenergic agonists, opiates, and anticholinergic agents.