Infectious Diarrhea

In Vivo and In Silico Studies of Flavonoids Isolated from Pistacia integerrima as Potential Antidiarrheal Agents

Pistacia integerrima leaf galls are used in several traditional medicines to cure many diseases such as diarrhea, asthma, fever, cough, vomiting, and hepatitis. The main goal of the present investigation was to assess the antidiarrheal effect of the Pistacia integerrima extracts/fractions and four isolated flavonoid compounds (1-4) on mice. An in vivo assay involving castor-oil-induced diarrhea was used to evaluate the antidiarrheal potential of extracts/fractions at 100, 200, and 400 mg/kg p.o., as well as isolated compounds at 5, 10, and 20 mg/kg p.o. Pretreatment of mice with extracts/fractions significantly attenuated castor-oil-induced diarrhea in a dose-dependent manner. Among all crude extracts and fractions, the ethyl acetate extract was the most effective with 100% protection against diarrhea followed by chloroform (75% protection) at 400 mg/kg p.o. Although all the isolated compounds exhibited strong antidiarrheal activity, isolated compounds 1 and 4 demonstrated 100% protection against diarrhea. Moreover, docking models were performed using the Molecular Operating Environment (MOE) and AutoDock software and suggested that the extracts and isolated compounds exert antidiarrheal activity by inhibiting mu-opioid and delta-opioid receptors. Therefore, our finding affords a strong pharmacological basis for the traditional use of P. integerrima galls in the treatment of diarrhea.

<p>Determinants of Acute Diarrhea Among Children Under-Five in Northeast Ethiopia: Unmatched Case–Control Study</p>

Background

Diarrheal disease is the second leading causes of death among under-five children. Most of the death due to diarrhea is reporting in developing countries. To prevent this highly prevalent problem, identifying the contributing factors across different settings is necessary. Therefore, this study aimed to identify the determinants of acute diarrhea among under-five children in the Northeast part of Ethiopia.

Methods

An institution-based unmatched case–control study was conducted among 306 under-five children from March to April 2019. A systematic random sampling technique was employed to select study participants. Data were collected by face to face interviews using a pretested structured questionnaire. Data were entered using Epi-info 7 and analyzed with SPSS version 20.0. We applied logistic regression analysis. Those variables with p-value <0.05 were significant determinants of acute diarrhea.

Results

Improper child’s stool disposal [AOR=4.12; 95% CI (1.25,13.5)], absence of home-based water treatment [AOR=2.85; 95% CI (1.27,6.42)], did not wash hand at critical times [AOR=5.47; 95% CI (1.68,17.8)], did not practice exclusive breastfeed [AOR=3.32; 95% CI (1.21,9.14], unable to get counseling from health professionals [AOR= 3.23; 95%,CI (1.15,13.5)], provide left over food to the child [AOR=2.96; 95% CI (1.19,7.32)], and maternal diarrhea [AOR=6.06; 95% CI (2.42,15.22)] were determinants of acute diarrhea among under five children.

Conclusion

Most of the determinants of acute diarrhea could be preventable. Thus, collaborative intervention by emphasizing health education about the importance of personal and environmental hygiene, safe food handling, exclusive breastfeeding practice, and home-based water treatment are essential.

In Silico Screening and Analysis of Broad-Spectrum Molecular Targets and Lead Compounds for Diarrhea Therapy

Diarrhoeal disease kills about 1.5 million human beings per year across the continents. The enterotoxigenic Escherichia coli (ETEC) pathotype has been noted as a major cause of diarrheal disease in human and livestock. The aim of this study is to identify broad-spectrum molecular targets in bacteria and broad-spectrum lead compounds (functional inhibitors) with high efficacy and no significant adverse implication on human systems, in relevance to diarrhea therapy through computational approaches which include phylogenetics, target prediction, molecular docking, and molecular flexibility dynamic simulations. Three molecular target genes, murA, dxr, and DnaE, which code for uridine diphosphate-N-acetylglucosamine-1-carboxyvinyltransferase, 1-deoxy-D-xylulose-5-phosphate reductoisomerase, and deoxyribonucleic acid polymerase III alpha subunit, respectively, were found to be highly conserved in 7 diarrhea-causing microbes. In addition, 21 potential compounds identified showed varied degree of affinity to these enzymes. At free energy cutoff of -8.0 kcal/mol, the highest effective molecular target was DNA polymerase III alpha subunit (PDB ID: 4JOM) followed by UDP-N-acetylglucosamine-1-carboxyvinyltransferase (PDB ID: 5UJS), and 1-deoxy-D-xylulose-5-phosphate reductoisomerase (PDB ID: 1ONN), while the highest effective lead compound was N-coeleneterazine followed by amphotericin B, MMV010576, MMV687800, MMV028694, azithromycin, and diphenoxylate. The flexibility dynamics of DNA polymerase III alpha subunit unraveled the atomic fluctuation which potentially implicated Asp593 as unstable active site amino acid residue. In conclusion, bacteria DnaE gene or its protein is a highly promising molecular target for the next generation of antibacterial drugs of the class of N-coeleneterazine.

Host Invasion by Pathogenic Amoebae: Epithelial Disruption by Parasite Proteins

The epithelium represents the first and most extensive line of defence against pathogens, toxins and pollutant agents in humans. In general, pathogens have developed strategies to overcome this barrier and use it as an entrance to the organism. Entamoeba histolytica, Naegleriafowleri and Acanthamoeba spp. are amoebae mainly responsible for intestinal dysentery, meningoencephalitis and keratitis, respectively. These amoebae cause significant morbidity and mortality rates. Thus, the identification, characterization and validation of molecules participating in host-parasite interactions can provide attractive targets to timely intervene disease progress. In this work, we present a compendium of the parasite adhesins, lectins, proteases, hydrolases, kinases, and others, that participate in key pathogenic events. Special focus is made for the analysis of assorted molecules and mechanisms involved in the interaction of the parasites with epithelial surface receptors, changes in epithelial junctional markers, implications on the barrier function, among others. This review allows the assessment of initial host-pathogen interaction, to correlate it to the potential of parasite invasion.

Curative effects of Distemonanthus benthamianus Baillon. Trunk-bark extracts on enteropathogenic Escherichia coli 31-induced diarrhea in rats

Background Distemonanthus benthamianus is used in the Western part of Cameroon to treat diarrheal episodes and infections. This study assessed its trunk-bark extracts activity against enteropathogenic Escherichia coli 31 (EPEC 31)-induced diarrhea in rats. Methods Aqueous and methanolic extracts were analyzed through high-performance liquid chromatography (HPLC). In vitro minimum inhibitory and bactericidal concentrations (MICs/MBCs) were evaluated on Enterococcus faecalis (ATCC 10,541), E. coli (ATCC 6539), Klebsiella pneumoniae (ATCC 13,883), Salmonella typhi (ATCC 6539) strains and on Proteus mirabilis, Pseudomonas aeruginosa (PA 01) and Shigella flexneri isolates using the microdilution method. Diarrhea was induced by inoculating rats with EPEC 31 (1.5 × 108 CFU/mL; p.o). Serum transaminases level assay and enzyme-linked immunosorbent assay (ELISA) for cytokines determination were performed. Hematoxylin-eosin (H-E) staining was used for intestinal tissue analysis. Results HPLC fingerprints of extracts showed presence of gallic acid and other unidentified compounds. The lowest MIC of 256 µg/mL was obtained with methanolic extract. At 100 mg/kg, both extracts significantly (p<0.001) inhibited diarrhea, with the methanolic extract being the most active. In addition, the methanolic extract significantly (p<0.001) increased the relative mass of the liver compared to negative control (Tween-DMSO 8%). The aqueous extract (100 mg/kg) significantly (p<0.01) increased alanine aminotransferase (ALT) serum concentration; while the methanolic extract (100 mg/kg) exhibited similar effect over aspartate aminotransferase (AST). At 50 and 100 mg/kg, the methanolic extract significantly (p<0.05 and p<0.01) decreased the Interleukin-1β (IL-1β) serum level, compared to negative control (Tween-DMSO 8%). Serum level of tumor necrosis factor alpha (TNF-α) significantly (p<0.001) decreased with 100 mg/kg of aqueous extract and all doses of methanolic extract. Inhibition of inflammatory cells tissue infiltration and epithelial regeneration was highly noticed in the ileum and colon of extracts-treated rats than in ciprofloxacin-treated animals. Conclusion These findings suggest that D. benthamianus trunk-bark extracts displayed therapeutic effects against infectious diarrhea in rats.