PAF formation by human gastrointestinal mucosa/submucosa in-vitro: release by ricinoleic acid, and inhibition by 5-aminosalicylic acid

Antidiarrheal activity of 19-deoxyicetexone isolated from Salvia ballotiflora Benth in mice and rats

The antidiarrheal properties of 19-deoxyicetexone, a diterpenoid isolated from Salvia ballotiflora were evaluated on castor oil-, arachidonic acid (AA)- and prostaglandin (PGE₂)-induced diarrhea in rodent models. The structure of 19-deoxyicetexone was determined by X-ray crystallography, mass spectrometry (EI-MS), as well as ultraviolet (UV-Vis), infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopies. This compound significantly and dose-dependently reduced frequency of stooling in castor oil-induced diarrhea, and at dose of 25 mg/kg it also inhibited diarrhea induced with AA, while it had no effect on PGE₂-induced diarrhea. This compound at doses of 25 mg/kg also diminished castor oil-induced enteropooling and intestinal motility, and inhibited the contraction of the rats' ileum induced by carbachol chloride at a concentration of 100 µg/mL. 19-Deoxyicetexone did not present acute toxicity at doses of 625 mg/kg. Its antidiarrheal activity may be due to increased reabsorption of NaCl and water and inhibition of the release of prostaglandins, gastrointestinal motility and fluid accumulation in the intestinal tracts of rats. These findings suggest that 19-deoxyicetexone may be used in the treatment of diarrhea, although more studies must be carried out to confirm this.

Assessment of antidiarrhoeal activity of the methanol extract of Xylocarpus granatum bark in mice model

The methanol extract of Xylocarpus granatum bark was studied for its antidiarrhoeal properties in experimental diarrhoea, induced by castor oil and magnesium sulphate in mice. At the doses of 250 and 500 mg/kg per oral, the methanol extract showed significant and dose-dependent antidiarrhoeal activity in both models. The extracts also significantly reduced the intestinal transit in charcoal meal test when compared to atropine sulphate (5 mg/kg; i.m.). The results showed that the extracts of Xylocarpus granatum bark have a significant antidiarrhoeal activity and supports its traditional uses in herbal medicine.

Antidiarrhoeal activity of the ethanol extract of Paederia foetida Linn. (Rubiaceae)

Paederia foetida L. is used as a remedy for diarrhoea and dysentery in Asia, but has not been investigated for its antidiarrhoeal properties. Antidiarrhoeal activity of 90% ethanol extract of Paederia foetida was investigated in this study using castor oil and magnesium sulphate-induced diarrhoea models in mice. The extract significantly increased the latent period of diarrhoea in both the models. In the castor oil study, the purging index (PI) value lowered in 1 h of the study at (100, 250 and 500 mg/kg) doses. The effect continued up to 6-h period only at 500 mg/kg dose. The plant notably reduced the purging index value in a dose-dependent manner in magnesium sulphate-induced diarrhoea. Paederia foetida, in general, reduced the gastrointestinal motility with barium sulphate milk both in 15- and 30-min time intervals. The extract significantly decreased the cisplatin-induced gastrointestinal motility at all doses at both time intervals. The extract also enhanced the morphine-induced reduction of motility at 500 mg/kg dose level at both time intervals. The results suggest that Paederia foetida showed antidiarrhoeal activity by inhibiting intestinal motility and justify its use in traditional medicine.

Increased ex-vivo colonic generation of PAF induced by diphenylmethane stimulant laxatives in rats, mice, guinea-pigs and rabbits

The effects of in-vivo treatment with bisacodyl, phenolphthalein, picosulphate, sulphosuccinate, mannitol and lactulose laxatives were examined on the ex-vivo formation of platelet-activating factor (PAF) by duodenum and colon of rat, mouse, guinea-pig and rabbit. Bisacodyl (10 mg kg-1), phenolphthalein (20 mg kg-1) and picosulphate (10 mg kg-1), but not sulphosuccinate (40 mg kg-1), mannitol (50 mg kg-1) or lactulose (50 mg kg-1), at doses that all caused laxation, markedly increased PAF in the colon (P < 0.01) but not in the duodenum. Intraluminal release of acid phosphatase was also significantly increased in the colon of rats treated with bisacodyl, phenolphthalein and picosulphate, but not in colons of animals treated with sulphosuccinate, mannitol or lactulose. The data show that enhanced generation of PAF is associated with the colonic damage induced by diphenylmethane laxatives, but do not show whether this is a cause or a consequence of the pathophysiological changes.