AIM： To investigate the effects of mangiferin on gas- trointestinal transit （GIT） in normal and constipated mice, together with the possible mechanism.METHODS： Intragastrically-administered charcoal mealwas used t...AIM： To investigate the effects of mangiferin on gas- trointestinal transit （GIT） in normal and constipated mice, together with the possible mechanism.METHODS： Intragastrically-administered charcoal mealwas used to measure GIT in overnight starved Swiss mice. In the first experiments, mangiferin （3 mg/kg, 10 mg/kg, 30 mg/kg, and 100 mg/kg, po） or tegaserod （1 mg/kg, ip） were administered 30 min before the char- coal meal to study their effects on normal transit. In the second series, mangiferin （30 mg/kg） was tested on delayed GIT induced by several different pharma- cological agonists （morphine, clonidine, capsaicin） or antagonists （ondansetron, verapamil, and atropine） whereas in the third series, mangiferin （30 mg/kg, 100 mg/kg and 300 mg/kg） or tegaserod （1 mg/kg） were tested on 6 h fecal pellets outputted by freely fed mice. The ratio of wet to dry weight was calculated and used as a marker of fecal water content. RESULTS： Mangiferin administered orally significantly （P 〈 0.05） accelerated GIT at 30 mg/kg and 100 mg/kg （89% and 93%, respectively）, similarly to 5-hydroxytrypta- mine4 （5-H%） agonist tegaserod （81%） when compared to vehicle-treated control （63%）. Co-administered man- giferin （30 mg/kg） totally reversed the inhibitory effect of opioid agonist morphine, 5-HT3-receptor antagonist ondansetron and transient receptor potential vanilloid-1 receptor agonist capsaicin on GIT, but only to a partial extent with the GIT-delay induced by ~2-adrenoceptor agonist clonidine, and calcium antagonist verapamil. However, co-administered atropine completely blocked the stimulant effect of mangiferin on GIT, suggesting the involvement of muscarinic acetylcholine receptor activation. Although mangiferin significantly enhanced the 6 h fecal output at higher doses （245.5±10.43 mg vs 161.9±10.82 mg and 227.1±20.11 mg vs 161.9±10.82 mg of vehicle-treated control, at 30 and 100 mg/ kg, P 〈 0.05, respectively）, the effect of tegaserod was more potent （297.4±7.42 mg vs 161.9±10.82 mg of vehicle-treated control, P 〈 0.05）. Unlike tegaserod, which showed an enhanced water content in fecal pel- lets （59.20%±1.09% vs 51.44%±1.19% of control, P 〈 0.05）, mangiferin evidenced no such effect, indi-cating that it has only a motor and not a secretomotor effect. CONCLUSION： Our data indicate the prokinetic action of mangiferin. It can stimulate the normal GIT and also overcome the drug-induced transit delay, via a choliner- gic physiological mechanism.展开更多
基金Supported by National Council of Technological and Scientific Development (CNPq)Ceará Foundation for the Support of Scientific and Technological Development of the Ceará State(FUNCAP),Brazil
文摘AIM： To investigate the effects of mangiferin on gas- trointestinal transit （GIT） in normal and constipated mice, together with the possible mechanism.METHODS： Intragastrically-administered charcoal mealwas used to measure GIT in overnight starved Swiss mice. In the first experiments, mangiferin （3 mg/kg, 10 mg/kg, 30 mg/kg, and 100 mg/kg, po） or tegaserod （1 mg/kg, ip） were administered 30 min before the char- coal meal to study their effects on normal transit. In the second series, mangiferin （30 mg/kg） was tested on delayed GIT induced by several different pharma- cological agonists （morphine, clonidine, capsaicin） or antagonists （ondansetron, verapamil, and atropine） whereas in the third series, mangiferin （30 mg/kg, 100 mg/kg and 300 mg/kg） or tegaserod （1 mg/kg） were tested on 6 h fecal pellets outputted by freely fed mice. The ratio of wet to dry weight was calculated and used as a marker of fecal water content. RESULTS： Mangiferin administered orally significantly （P 〈 0.05） accelerated GIT at 30 mg/kg and 100 mg/kg （89% and 93%, respectively）, similarly to 5-hydroxytrypta- mine4 （5-H%） agonist tegaserod （81%） when compared to vehicle-treated control （63%）. Co-administered man- giferin （30 mg/kg） totally reversed the inhibitory effect of opioid agonist morphine, 5-HT3-receptor antagonist ondansetron and transient receptor potential vanilloid-1 receptor agonist capsaicin on GIT, but only to a partial extent with the GIT-delay induced by ~2-adrenoceptor agonist clonidine, and calcium antagonist verapamil. However, co-administered atropine completely blocked the stimulant effect of mangiferin on GIT, suggesting the involvement of muscarinic acetylcholine receptor activation. Although mangiferin significantly enhanced the 6 h fecal output at higher doses （245.5±10.43 mg vs 161.9±10.82 mg and 227.1±20.11 mg vs 161.9±10.82 mg of vehicle-treated control, at 30 and 100 mg/ kg, P 〈 0.05, respectively）, the effect of tegaserod was more potent （297.4±7.42 mg vs 161.9±10.82 mg of vehicle-treated control, P 〈 0.05）. Unlike tegaserod, which showed an enhanced water content in fecal pel- lets （59.20%±1.09% vs 51.44%±1.19% of control, P 〈 0.05）, mangiferin evidenced no such effect, indi-cating that it has only a motor and not a secretomotor effect. CONCLUSION： Our data indicate the prokinetic action of mangiferin. It can stimulate the normal GIT and also overcome the drug-induced transit delay, via a choliner- gic physiological mechanism.
