Prostaglandin-induced diarrhoea

Investigation of Antibacterial and Anti-Diarrhoeal Activities of 80% Methanol Leaf and Fruit Extract of Leonotis ocymifolia (Burm. F) Iwarsson (Lamiaceae)

BACKGROUND

Leonotis ocymifolia (Burm.F) Iwarsson (Lamiaceae) is among the medicinal plants that are claimed to have various pharmacologic activities. However the leaves and fruits of L. ocymifolia have not yet been explored scientifically for antibacterial and anti-diarrhoeal activities. This study was aimed at investigating the anti-diarrhoeal and antibacterial activities of 80% methanol leaf and fruit extract of Leonotis ocymifolia in mice and selected diarrhea causing bacterial species.

METHODS

The leaves and fruits of Leonotis ocymifolia were extracted using 80% methanol through maceration technique. The anti-diarrheal activity was evaluated using a castor oil induced diarrheal model, prostaglandin induced anti-enteropooling, and castor oil induced charcoal meal test in mice of either sex. Data were analyzed using one-way analysis of variance followed by Tukey post-hoc test. The antibacterial activity was evaluated on using an agar well diffusion assay. Bacterial species used were Salmonella typhi, Salmonella paratyphi, Salmonella typhimurium, Shigella species, Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli. For anti-diarrhoeal activity, the extract was tested at 100, 200, and 400 mg/kg. Positive and negative control groups were treated with loperamide (3 mg/kg) and 2% tween 80 (10 mL/kg), respectively.

RESULTS

A significant (p<0.05) reduction in frequency of wet stools and watery content of diarrhea as well as in delaying onset of diarrhea as compared to controls was observed in mice at the stated doses. The extract showed a dose-dependent inhibition in all used models. L. ocymifolia leaf and fruit extract also showed antimicrobial activity against all tested organisms.

CONCLUSION

Results from this study collectively indicated that 80% methanol leaf and fruit extracts of L. ocymifolia possessed significant anti-diarrhoeal activity and antibacterial activities, hence provides the scientific base for its traditional use as a diarrhea treatment.

Influence of prostaglandin E2 infusion on gastrointestinal electrical activity in the conscious piglet

In 5 conscious piglets with implanted electrodes in the antrum pylori, duodenum, jejunum and ileum, electromyographic activity was recorded daily on a multichannel recorder with a time constant of 0.03 s for intestinal and of 1 s for gastric recordings, and simultaneously integrated at 20 s intervals. PGE2 was infused for 2 h in relatively low doses of 0.1 and 1 microgram/kg/min, to avoid excessive hypersecretion, which would disguise direct effects. Each dose was tested once in each animal with a 1 week interval. Infusion of 0.1 microgram/kg/min revealed no significant changes in antral and small intestinal electrical activity. One microgram/kg/min however induced a strong depression of fast oscillations until the end of the infusion and prolongation of the inhibitory phase in the antrum following a duodenal phase of regular spiking activity. Intestinal segments displayed a prolongation of the quiescent phase and a decrease in the integrated area curve of the phase of irregular spiking activity. Recurrence of the phase of regular spiking activity was unaltered in either segment. These data suggest that the direct effect of PGE2 on gastrointestinal motility in the piglet is a partial inhibition of intestinal contractions.

Prostanoids in jejunal biopsy specimens of celiac children with active disease and on challenge diet. Radioimmunologic evaluation

Prostanoid generation (prostaglandin E2 and thromboxane B2) in jejunal biopsy specimens from celiac patients was evaluated, comparing celiac patients with celiac patients on challenge diet and controls. Generation of prostaglandin E2 in jejunal specimens from 14 children with active celiac disease was significantly higher (341.8 +/- 82.3 ng/g; mean +/- SEM) than that from 7 celiac patients on gluten challenge diet (69.4 +/- 13.2 ng/g) or 8 normal children (92 +/- 23 ng/g) (p less than 0.05). In contrast, thromboxane B2 generation in jejunal specimens from all three groups did not show any statistically significant variation. Our results indicate that prostaglandin E2 generation is not merely related to the activity of clinical symptoms, since patients receiving gluten challenge had prostaglandin E2 levels that did not differ from those of controls.

Infantile colic: incidence and treatment in a Norfolk community

In a prospective study of 1019 infant and mother pairs, 268 infants suffered with 'infantile colic'. Significantly more of these were breast fed, supporting the proposed theory of a colic-producing factor in breast milk. Social class and maternal education were not related to the incidence of colic. Seventy-two percent of our infants with colic suffered from classical evening colic. The symptoms did not disappear from all the infants by 3 months - over 38% continued to have symptoms after 3 1/2 months of age. Treatment is limited, but merbentyl helped to relieve symptoms to a varying degree in over 60% of the infants who tried it. The family relationships are often strained during this period and this appears to persist when at one year of age significantly more of these infants were described as demanding, miserable and bad-tempered by their mothers.

Stool output and composition in the chronic non-specific diarrhoea syndrome

Stool output and composition were studied in 7 children with chronic, non-specific diarrhoea syndrome and the results were compared with those of children with malabsorption due to cystic fibrosis or to bacterial overgrowth syndrome, and with stools from controls. Daily quantities of stool, fat, and total bile acids were normal in patients with chronic, non-specific diarrhoea syndrome. Faecal sodium concentration was high compared with that of controls or patients with cystic fibrosis. The extractable water phase of stools appreciably increased in patients with chronic, non-specific diarrhoea syndrome and contained 50% of the total stool bile acids; this was also the case in patients with bacterial overgrowth syndrome. It is suggested that a secretory state of the large-bowel due to mucosal exposure of large quantities of bile salts in the extractable water phase may be contributory to the diarrhoea of chronic, non-specific diarrhoea syndrome.

Toddler diarrhoea and prostaglandins

Chronic, non-specific `toddler diarrhoea' in young children is often accompanied by an increase in plasma prostaglandins, particularly PGF₂α. Although treatment with drugs is generally unnecessary, aspirin is effective in most children with high prostaglandins, and treatment with loperamide is effective in most children with toddler diarrhoea, regardless of the plasma prostaglandin levels. The source of the increased plasma prostaglandins is not known.

Prostaglandins in human milk

Prostaglandins E and F have been shown to be present in breast milk in over 100 times the concentrations found in adult plasma. The ratio of the concentration of the principal circulating metabolite of prostaglandin F (13, 14-dihydro-15-ketoprostaglandin F) to prostaglandin F itself is low (0.3 to 0.5, compared with 15.8 in adult plasma), implying that prostaglandins may have a relatively long half-life in milk. In addition inactive metabolites of thromboxane A2 and prostacyclin are also found in significant amounts. It is speculated that milk prostaglandin play a role in modulating neonatal physiology--for example, gut motility.