Contractile effect of radish and betel nut extracts on rabbit gallbladder

Raphanus sativus (abbreviated in this paper as Rs.Cr) and Areca catechu (Ac.Cr), commonly known as radish and betel nut respectively, are traditionally used in South Asia for different gastrointestinal, gallbladder, and hepatic diseases. There has not been any study to see how they modulate gallbladder contractility. We selected isolated rabbit gallbladder tissue preparations, mounted them in tissue baths containing Krebs-Henseleit solution at 37°C, and then recorded the changes in baseline tone of the tissues upon administration of Rs.Cr and Ac.Cr. Both the extracts exhibited concentration-dependent stimulant effect on the baseline tone of gallbladder tissues, similar to carbachol, a muscarinic receptor agonist. The stimulant effect of the extract, as well as that of carbachol, was completely blocked in the presence of atropine, a muscarinic antagonist, indicating similarity in the mechanism of action of the extracts with carbachol. The result shows potential of these extracts to contract the gallbladder and to subsequently increase bile secretion, but this remains to be investigated in detail. This study justifies the traditional use of radish and betel nut in different gastrointestinal disorders.