Antidiarrheal activity of extracts from Maytenus gonoclada and inhibition of Dengue virus by lupeol

ABSTRACT Diarrhea is an infectious disease caused by bacterial, virus, or protozoan, and dengue is caused by virus, included among the neglected diseases in several underdeveloped and developing countries, with an urgent demand for new drugs. Considering the antidiarrheal potential of species of Maytenus genus, a phytochemical investigation followed by antibacterial activity test with extracts of branches and heartwood and bark of roots from Maytenus gonoclada were conducted. Moreover, due the frequency of isolation of lupeol from Maytenus genus the antiviral activity against Dengue virus and cytotoxicity of lupeol and its complex with β-cyclodextrins were also tested. The results indicated the bioactivity of ethyl acetate extract from branches and ethanol extract from heartwood of roots of M. gonoclada against diarrheagenic bacteria. The lupeol showed potent activity against Dengue virus and low cytotoxicity in LLC-MK2 cells, but its complex with β-cyclodextrin was inactive. Considering the importance of novel and selective antiviral drug candidates the results seem to be promising.

Investigation on the gastroprotective and antidiarrhoeal properties of Aegle marmelos unripe fruit extract.

The Study was designed to verify the gastroprotective and antidiarrhoeal effects of unripe fruit extract of Aegle marmelos Corr. The gastroprotective function of this extract 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 the 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 demonstrated that pretreatment of animals with unripe fruit extract (50 and 100 mg/kg, i.p.) produces a significant inhibition of gastric lesion induced by ethanol but not those induced by restraint stress or indomethacin and suggest a probable involvement of a prostaglandin-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 raw fruit extract. Furthermore, the extract antagonized 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 unripe fruit extract of A. marmelos Corr., since inhibition of intestinal motility and secretion can control clinical diarrhoea.