Laxative activities of Mareya micrantha (Benth.) Müll. Arg. (Euphorbiaceae) leaf aqueous extract in rats.

BACKGROUND: Mareya micrantha (Benth.) Müll. Arg. (Euphorbiaceae) is a shrub that is commonly used in Côte d'Ivoire (West Africa) for the treatment of constipation and as an ocytocic drug. The present study was carried out to investigate the laxative activity of Mareya micrantha in albino's Wistar rats. METHODS: Rats were divided in 5 groups of 5 animals each, first group as control, second group served as standard (sodium picosulfate) while group 3, 4 and 5 were treated with leaf aqueous extract of Mareya micrantha at doses of 100, 200 and 400 mg/kg body weight (b.w.), per os respectively. The laxative activity was determined based on the weight of the faeces matter. The effects of the leaves aqueous extract of Mareya micrantha and castor oil were also evaluated on intestinal transit, intestinal fluid accumulation and ions secretion. RESULTS: Phytochemicals screening of the extract revealed the presence of flavonoids, alkaloids, tannins, polyphenols, sterols and polyterpenes. The aqueous extract of Mareya micrantha applied orally (100, 200 and 400 mg/kg; p.o.), produced significant laxative activity and reduced loperamide induced constipation in dose dependant manner. The effect of the extract at 200 and 400 mg/kg (p.o.) was similar to that of reference drug sodium picosulfate (5 mg/kg, p.o). The same doses of the extract (200 and 400 mg/kg, p.o.) produced a significant increase (p < 0.01) of intestinal transit in comparison with castor oil (2 mL) (p < 0.01). Moreover, the extract induced a significant enteropooling and excretion of Cl-, Na+, K+ and Ca2+ in the intestinal fluid (p < 0.01). CONCLUSIONS: The results showed that the aqueous extract of Mareya micrantha has a significant laxative activity and supports its traditional use in herbal medicine.

Distribution and Risk of Mycolactone-Producing Mycobacteria Transmission within Buruli Ulcer Endemic Communities in Côte d'Ivoire.

In Buruli ulcer (BU) endemic communities, most mycolactone-producing mycobacteria (MPM), including Mycobacterium ulcerans, the causative agent, are present in water bodies used by inhabitants; yet, their mode of transmission is still unclear. This study aimed to assess the distribution of MPM strains, both from human suspected cases and aquatic environments, for identifying possible transmission modes within two BU endemic districts, Daloa and Tiassalé (Taabo), in Côte d'Ivoire. Collected samples were processed using conventional polymerase chain reaction and screened for the presence of non-tuberculous mycobacteria (NTM) and MPMs using 16S rRNA, IS2404 and enoyl reductase (ER) primers. MPM-positive samples were further discriminated using variable number tandem repeat (VNTR) typing and sequencing. 16S rRNA and IS2404 sequences confirmed that 94% of the clinical samples contained MPMs. For environmental samples, 53% were contaminated with NTMs, of which 17% contained MPMs particularly M. ulcerans, suggesting that water-related activities could predispose inhabitants to BU transmission. MPM discrimination by VNTR at four M. ulcerans Agy99 loci identified genotype C, previously reported in Côte d'Ivoire as the most dominant profile. Phylogenetic clustering on the basis of genetic diversity in the MIRU 1 locus showed two main M. ulcerans lineages in Côte d'Ivoire.

Polymorphisms of the Pfatpase 6 and Pfcrt gene and their relationship with the in vitro susceptibility to dihydroartemisinin and chloroquine of Plasmodium falciparum isolates from Abobo, Côte d'Ivoire.

As a result of widespread resistance to chloroquine (CQ) and sulphadoxine-pyrimethamine (SP), artemisinin-based combination therapy (ACT) has been recommended as a first-line anti-malarial regimen in Côte d'Ivoire since 2005. A thorough understanding of the molecular bases of P. falciparum resistance to existing drugs is therefore needed. The aims of this study were to analyze the in vitro sensitivity of P. falciparum field isolates from Abobo to CQ, pyronaridine (PYR) and dihydroartemisinine (DHA), and to investigate the polymorphisms associated with drug resistance. The standard in vitro drug sensitivity microtechnique recommended by the WHO was used to assess the sensitivity of Plasmodium falciparum isolates collected in December 2006. The Pfcrt haplotype 76 was analysed by PCR-RFLP while Pfatpase 6 amplification products were sequenced. Associations between drug sensitivity and parasite gene polymorphisms were evaluated with Cohen's kappa test. The correlation between the IC50 values for different drugs was assessed by the coefficient of determination (r²). Significance was assumed at p<0.05. Of 128 in vitro tests performed, 112 (87.5%) were successful. Of the isolates, 56.2% were resistant for CQ and 48% for PYR. One isolate (3.6%) demonstrated reduced DHA sensitivity (IC50 higher than 10 nM). The mutant K76T pfcrt codon, present in 90% of DNA fragments analyzed, was associated with CQ-R (ĸ=0.76). The N669Y (16.1%), D734Y (28.6%) and D734H (1.8%) isolates were found to have mutant Pfatpase6, however, these mutations were not associated with diminished DHA sensitivity (k=0.01). These high levels of antimalarial drug resistance in Abobo (Côte d'Ivoire) demand further studies of drug efficacy across the whole country.

Monkey CV1 cell line expressing the sheep-goat SLAM protein: a highly sensitive cell line for the isolation of peste des petits ruminants virus from pathological specimens.

Peste des petits ruminants (PPR) is an important economically transboundary disease of sheep and goats caused by a virus which belongs to the genus Morbillivirus. This genus, in the family Paramyxoviridae, also includes the measles virus (MV), canine distemper virus (CDV), rinderpest virus (RPV), and marine mammal viruses. One of the main features of these viruses is the severe transient lymphopaenia and immunosuppression they induce in their respective hosts, thereby favouring secondary bacterial and parasitic infections. This lymphopaenia is probably accounted for by the fact that lymphoid cells are the main targets of the morbilliviruses. In early 2000, it was demonstrated that a transmembrane glycoprotein of the immunoglobulin superfamily which is present on the surface of lymphoid cells, the signalling lymphocyte activation molecule (SLAM), is used as cellular receptor by MV, CDV and RPV. Wild-type strains of these viruses can be isolated and propagated efficiently in non-lymphoid cells expressing this protein. The present study has demonstrated that monkey CV1 cells expressing goat SLAM are also highly efficient for isolating PPRV from pathological samples. This finding suggests that SLAM, as is in the case for MV, CDV and RPV, is also a receptor for PPRV.