An overview of anti-diabetic plants used in Gabon: Pharmacology and Toxicology

© 2017 Elsevier B.V. All rights reserved.Ethnopharmacological relevance: The management of diabetes mellitus management in African communities, especially in Gabon, is not well established as more than 60% of population rely on traditional treatments as primary healthcare. The aim of this review was to collect and present the scientific evidence for the use of medicinal plants that are in currect by Gabonese traditional healers to manage diabetes or hyperglycaemia based here on the pharmacological and toxicological profiles of plants with anti-diabetic activity. There are presented in order to promote their therapeutic value, ensure a safer use by population and provide some bases for further study on high potential plants reviewed. Materials and methods: Ethnobotanical studies were sourced using databases such as Online Wiley library, Pubmed, Google Scholar, PROTA, books and unpublished data including Ph.D. and Master thesis, African and Asian journals. Keywords including ‘Diabetes’ ‘Gabon’ ‘Toxicity’ ‘Constituents’ ‘hyperglycaemia’ were used. Results: A total of 69 plants currently used in Gabon with potential anti-diabetic activity have been identified in the literature, all of which have been used in in vivo or in vitro studies. Most of the plants have been studied in human or animal models for their ability to reduce blood glucose, stimulate insulin secretion or inhibit carbohydrates enzymes. Active substances have been identified in 12 out of 69 plants outlined in this review, these include Allium cepa and Tabernanthe iboga. Only eight plants have their active substances tested for anti-diabetic activity and are suitables for further investigation. Toxicological data is scarce and is dose-related to the functional parameters of major organs such as kidney and liver. Conclusion: An in-depth understanding on the pharmacology and toxicology of Gabonese anti-diabetic plants is lacking yet there is a great scope for new treatments. With further research, the use of Gabonese anti-diabetic plants is important to ensure the safety of the diabetic patients in Gabon.Peer reviewedFinal Accepted Versio

The Helicobacter pylori Genome Project : insights into H. pylori population structure from analysis of a worldwide collection of complete genomes

Helicobacter pylori, a dominant member of the gastric microbiota, shares co-evolutionary history with humans. This has led to the development of genetically distinct H. pylori subpopulations associated with the geographic origin of the host and with differential gastric disease risk. Here, we provide insights into H. pylori population structure as a part of the Helicobacter pylori Genome Project (HpGP), a multi-disciplinary initiative aimed at elucidating H. pylori pathogenesis and identifying new therapeutic targets. We collected 1011 well-characterized clinical strains from 50 countries and generated high-quality genome sequences. We analysed core genome diversity and population structure of the HpGP dataset and 255 worldwide reference genomes to outline the ancestral contribution to Eurasian, African, and American populations. We found evidence of substantial contribution of population hpNorthAsia and subpopulation hspUral in Northern European H. pylori. The genomes of H. pylori isolated from northern and southern Indigenous Americans differed in that bacteria isolated in northern Indigenous communities were more similar to North Asian H. pylori while the southern had higher relatedness to hpEastAsia. Notably, we also found a highly clonal yet geographically dispersed North American subpopulation, which is negative for the cag pathogenicity island, and present in 7% of sequenced US genomes. We expect the HpGP dataset and the corresponding strains to become a major asset for H. pylori genomics

Evaluation of antimicrobial activity of the fruitrind of Picralima nitida (Aapocynaceae) and the stem bark of Cylicodscus gabunensis (Mimosaceae)

Ethyl acetate(EA) extract of the stem bark of Cylicodiscus gabunensis (CG) and methanol(M) extract of the fruit-rinds of Picralima nitida (PN) were analysed phytochemically and evaluated for their antimicrobial activity against 17 pathogenic species isolated from patient: Escherichia coli, Klebsiella pneumoniae, Shigella dysenteriae, Shigella flexneri, Morganella morganii, Proteus vulgaris, Proteus mirabilis, Salmonella thyphi, Citrobacter freundii, Enterobacter cloacae, Enterobacter agglomerans, Staphylococcus aureus, Streptococcus feacalis, Pseudomonas aeruginosa, Bacillus cereus T, Candida albicans and Candida glabrata. Alkaloids, flavonoids, saponins, polyphenols, cardiac glycoside and glycoside were detected in the (M) extract of PN whereas flavonoids, saponins, tannins, polyphenols, coumarins, triterpenes and/or sterols and reducing sugars were detected in the (EA) extract of CG. The best MIC and MBC values for the microorganisms sensitive to the (EA) extract of CG were 0.00078 and 0.00315mg/ml respectively whereas its were 0.00078 and 0.001525mg/ml respectively to the methanol extract of PN. The greater and remarkable antimicrobial activities of the (EA) extract of CG were recorded with Staphylococcus aureus, Proteus vulgaris and Bacillus cereus T whereas it was recorded with Proteus mirabilis for the (M) extract of PN. These results provide a rationalization for the traditional use of both plants for the treatment of infections diseases. Keywords: Antimicrobial activity, Cylicodiscus gabunensis, Picralima nitida West African Journal of Pharmacology and Drug Research Vol. 21 (1&2) 2005: pp. 6-1