Diarrhée et cascade inflammatoire: une nouvelle approche

Antioxidant activity of dichloromethane fraction of Dichrocephala integrifolia in Salmonella typhi-infected rats

OBJECTIVE

Infectious diseases such as typhoid fever lead to the formation of free radicals which can damage the body. Many medicinal plants have antioxidant molecules that neutralize free radicals. The present work evaluated the antioxidant activity and histopathological effects of the dichloromethane fraction of Dichrocephala integrifolia in Salmonella typhi-infected rats.

METHODS

The S. typhi-infected rats concurrently received daily doses of D. integrifolia extract at doses of 25, 50 and 100 mg/kg body weight or ciprofloxacin (5 mg/kg body weight) for 15 days. Body temperature was measured daily during infection and treatment periods. At the end of treatment period, the animals were sacrificed and biological responses including hematological parameters, superoxide dismutase and catalase activities, and glutathione, malondialdehyde and nitric oxide concentrations were evaluated.

RESULTS

The elevated body temperature induced by infection was significantly decreased in animals treated with 25, 50 or 100 mg/kg of the extract. Platelet levels decreased slightly in infected rats, while treatment with the dichloromethane fraction of D. integrifolia significantly increased platelet levels; this response was greater than that elicited by ciprofloxacin. The doses of 50 and 100 mg/kg of the dichloromethane fraction of D. integrifolia notably decreased monocyte and neutrophil values. Activity of superoxide dismutase and catalase and levels of glutathione in the tissues of treated animals were increased significantly (P < 0.01), while malondialdehyde and nitric oxide levels were significantly decreased (P < 0.01), following treatment with the dichloromethane fraction of D. integrifolia.

CONCLUSION

The results of this study show that the dichloromethane fraction of D. integrifolia has protective effects against a series of pathological conditions initiated by oxidation and tissue damage in the course of a S. typhi infection.

Antityphoid properties and toxicity evaluation of Harungana madagascariensis Lam (Hypericaceae) aqueous leaf extract

CONTEXT

Harungana madagascariensis Lam is commonly used in Cameroonian folk medicine for the treatment of malaria and typhoid fever.

OBJECTIVE

To investigate the therapeutic potentials of H. madagascariensis aqueous leaf extract for the treatment of salmonellosis (e.g. typhoid fever, gastroenteritis).

MATERIALS AND METHODS

A Salmonella Typhimurium-infected rat model was used. The faeces of these rats were analysed for viable Salmonella Typhimurium before and after infection, and during the treatment period. The physiological, biochemical and histopathological markers of possible side effects of the extract were also studied using standard methods and kits.

RESULTS AND DISCUSSION

The in vivo antisalmonellal study revealed that this extract significantly (P<0.05) reduced the number of viable Salmonella Typhimurium recovered from faeces, and could stop salmonellosis after 10 days of treatment for male and female rats, with non-toxic doses. However, the biochemical and histological analyses revealed that at relatively high-doses (≥100mg/kg for females and 200mg/kg for males) the extract could induce liver damage, as illustrated by a rise of serum transaminases (ALT and AST), significant inflammation of the parenchyma and portal vein, as well as cell necrosis. There were also increases in cholesterol levels in both sexes. No significant unwanted side effect of the extract was observed on the kidney, as shown by both serum and urinary creatinine, and urinary protein levels.

CONCLUSION

The results obtained showed that H. madagascariensis has a promising antisalmonellal effect and, therefore, the potential to provide an effective treatment against salmonellosis, including typhoid fever.

Anti-diarrheal effects of diosmectite in the treatment of acute diarrhea in children: a review

Acute diarrhea caused by an infectious organism is highly prevalent, particularly in developing countries, and is usually self-limiting. The condition is a major contributor to the global disease burden and is associated with a significant economic cost. The disease is common in children aged <5 years. It occurs as the result of exposure to a diarrheogenic agent that alters intestinal absorption and/or secretion, resulting in an increase in the volume of water that enters the colon beyond that which can be absorbed. Diarrhea almost always occurs by one or more of four mechanisms: disruption of osmotic forces in the intestine; disruption of normal secretory processes; disruption of epithelial cells or the epithelial tight junctions; or motility disorders. Oral rehydration therapy (ORT) is central to the management of acute diarrhea, and is sufficient to prevent complications due to dehydration in most patients while the disease runs its course. However, ORT has no effect on the duration of the disease or frequency of bowel motions, and any agent that could meet these needs would therefore be a useful addition to ORT. Diosmectite is a natural aluminomagnesium silicate clay with a lamellar, non-fibrous crystalline structure that gives it strong adsorbent properties. Its mechanisms of action are not yet fully understood, but are probably multiple. Diosmectite reduces inflammation, modifies mucus rheologic properties, inhibits mucolysis, and adsorbs bacteria, bacterial enterotoxins, viruses and other potentially diarrheogenic substances. A number of studies have shown that diosmectite reduces the duration of diarrhea and decreases the frequency of bowel motions after 2 days of treatment in children with mild-to-moderate acute diarrhea. Two recent trials have indicated a reduction in stool output with diosmectite. Because of its very favorable safety profile, with no serious adverse effects, diosmectite is frequently used, mainly in European countries but also in Asia and Africa. Diosmectite should be used as an adjunct, not an alternative, to ORT and, when needed, to antibacterial therapy.