Study of the effect of aqueous extract of Grewia tenax fruit on iron absorption by everted gut sac

Grewia tenax roots, leaves, juice and fruit decoctions have been used in Africa and Southeast Asiatic countries for a variety of medical purposes. In this investigation, we report the effect of aqueous extract of Grewia tenax fruit (AEGTF) on the variation in vitro of iron absorption. The incubation of freshly prepared rat everted gut sac (EGS) in Ringer medium containing FeSO4 in the absence of AEGTF showed that in stomach there is iron absorption only at 15 min of incubation time, whereas, at duodenum and jejunum, iron uptake occurs just after I min of incubation time and the maximum of iron absorption is registered at 15 min of incubation time. Addition of AEGTF at different concentrations favors significantly this iron transfer from the mucous side toward the serous one. The maximum of iron absorption was carried out in the presence of AEGTF at 10 mg/ml and 5 min of incubation time in stomach, duodenum and jejunum. AEGTF used at high doses (20 and 30 mg/ml) reduced significantly iron uptake suggesting a probable toxic effect of this extract. Histological studies confirmed the presence of cytotoxic signs as multinucleated giant cells and the disappearance of enterocyte border brush. With the aim of elucidating the mechanism of action of AEGTF, we are attempting to isolate the active principles present in this extract. (c) 2005 Elsevier Ireland Ltd. All rights reserved.