Antidiarrheal activity of some selected Nigerian plants used in traditional medicine

Context: Herbal preparations of the various parts of Vitellaria paradoxa, Neorautanenia mitis, Senna surattensis, and Hydnora abyssinica have been used in the Nigerian traditional medical practice to treat the symptoms of diarrhea in humans and animals. Aims: This study aims to validate claims of the traditional use of these plants in the treatment of diarrhea and provide a scientific basis for further studies. Materials and Methods: The median lethal dose (LD50) values of the extracts were obtained using the Limit test. Castor oil induced diarrhea and intestinal transit (motility) models in albino rats were used to determine the antidiarrheal activity. Graded doses of the extracts were administered to 3 test groups, while the positive control groups were given standard drugs (atropine and loperamide) and the negative control groups received distilled water per os. Results: The LD50 was considered higher than 2000 mg/Kg for all the extracts. In the castor oil-induced diarrhea model, the highest percentage inhibition of defecation was observed in the test groups treated with the extracts of H. abyssinica (82%) followed by S. surattensis (81%), N. mitis (66%), and V. paradoxa (32%). H. abyssinica extract significantly decreased the intestinal transit of charcoal meal compared to the other extracts. Conclusion: The antidiarrheal activities of all the extracts give credence to their traditional use. H. abyssinica comparatively had the best antidiarrheal activity and has the potential as an antidiarrheal agent. Thus, the need for further studies of this extract to investigate active fractions, isolate and characterize active compounds, and determine their activities and safety

Highly Pathogenic Avian Influenza Virus Subtype H5N1 in Africa: A Comprehensive Phylogenetic Analysis and Molecular Characterization of Isolates

Highly pathogenic avian influenza virus A/H5N1 was first officially reported in Africa in early 2006. Since the first outbreak in Nigeria, this virus spread rapidly to other African countries. From its emergence to early 2008, 11 African countries experienced A/H5N1 outbreaks in poultry and human cases were also reported in three of these countries. At present, little is known of the epidemiology and molecular evolution of A/H5N1 viruses in Africa. We have generated 494 full gene sequences from 67 African isolates and applied molecular analysis tools to a total of 1,152 A/H5N1 sequences obtained from viruses isolated in Africa, Europe and the Middle East between 2006 and early 2008. Detailed phylogenetic analyses of the 8 gene viral segments confirmed that 3 distinct sublineages were introduced, which have persisted and spread across the continent over this 2-year period. Additionally, our molecular epidemiological studies highlighted the association between genetic clustering and area of origin in a majority of cases. Molecular signatures unique to strains isolated in selected areas also gave us a clearer picture of the spread of A/H5N1 viruses across the continent. Mutations described as typical of human influenza viruses in the genes coding for internal proteins or associated with host adaptation and increased resistance to antiviral drugs have also been detected in the genes coding for transmembrane proteins. These findings raise concern for the possible human health risk presented by viruses with these genetic properties and highlight the need for increased efforts to monitor the evolution of A/H5N1 viruses across the African continent. They further stress how imperative it is to implement sustainable control strategies to improve animal and public health at a global level

Yersinia enterocolitica, a Neglected Cause of Human Enteric Infections in Côte d’Ivoire

International audienceBackground: Enteropathogenic Yersinia circulate in the pig reservoir and are the third bacterial cause of human gastrointestinal infections in Europe. In West Africa, reports of human yersiniosis are rare. This study was conducted to determine whether pathogenic Yersinia are circulating in pig farms and are responsible for human infections in the Abidjan District. Methodology/Principal findings: From June 2012 to December 2013, pig feces were collected monthly in 41 swine farms of the Abidjan district. Of the 781 samples collected, 19 Yersinia strains were isolated in 3 farms: 7 non-pathogenic Yersinia intermedia and 12 pathogenic Yersinia enterocolitica bioserotype 4/O:3. Farm animals other than pigs and wild animals were not found infected. Furthermore, 2 Y. enterocolitica 4/O:3 strains were isolated from 426 fecal samples of patients with digestive disorders. All 14 Y. enterocolitica strains shared the same PFGE and MLVA profile, indicating their close genetic relationship. However, while 6 of them displayed the usual phage type VIII, the other 8 had the highly infrequent phage type XI. Whole genome sequencing and SNP analysis of individual colonies revealed that phage type XI strains had unusually high rates of mutations. These strains displayed a hypermutator phenotype that was attributable to a large deletion in the mutS gene involved in DNA mismatch repair. Conclusions/Significance: This study demonstrates that pathogenic Y. enterocolitica circulate in the pig reservoir in Côte d'Ivoire and cause human infections with a prevalence comparable to that of many developed countries. The paucity of reports of yersiniosis in West Africa is most likely attributable to a lack of active detection rather than to an absence of the microorganism. The identification of hypermutator strains in pigs and humans is of concern as these strains can rapidly acquire selective advantages that may increase their fitness, pathogenicity or resistance to commonly used treatments