Investigations on the gastroprotective and antidiarrhoeal properties of ternatin, a tetramethoxyflavone from Egletes viscosa.

Abstract

The study was designed to verify the gastroprotective and antidiarrhoeal effects of ternatin, tetramethoxyflavone isolated from Egletes viscosa Less. The gastroprotective function of ternatin was evaluated in rats against gastric mucosal damage induced by hypothermic restraint stress, absolute ethanol, and indomethacin, whereas the antidiarrhoeal activity was investigated by studying its influence on gastrointestinal transit as measured by a charcoal marker and on castor oil-induced accumulation of intestinal fluid in mice and also on contractile responses evoked by acetylcholine, histamine, serotonin, and barium chloride in isolated guinea-pig ileum. The results demonstrate that pretreatment of animals with the plant flavonoid (25 and 50 mg/kg, i.p.) produces a significant inhibition of gastric lesions induced by ethanol but not those induced by restraint stress or indomethacin and suggest a probable involvement of a prostaglandins-independent mechanism of gastroprotection. At similar doses, both the intestinal transit as well as the accumulation of intestinal fluids induced by castor oil in mice were significantly inhibited by ternatin. Furthermore, the flavonoid antagonised the contractile responses evoked by different agonists on guinea-pig ileum in vitro and its inhibitory potential for the drugs are in the order of acetylcholine > histamine > serotonin > barium chloride. Taken together, these results point out a possible antidiarrhoeal effect of ternatin since inhibition of intestinal motility and secretion can greatly control clinical diarrhoea.