Cholinergic and anticholinesterase activities of total protein extract of Morinda morindoïdes on isolated rabbit duodenum

Traditional herbal medicines such as Morinda morindoïdes are used for treatment of intestinal disorders including constipation in Ivory Coast. The aim of present study was to investigate the effect of total protein of Morinda morindoïdes extract (PT-Mm) on rabbit duodenum contractility and the involved possible mechanism(s). PT-Mm was extracted according to the saturation method of Dawson with ammonium sulfate. The cholinergic effect of the extract was determined by the in vitro organ bath method. The acetylcholinesterase (AChE) extracted from rabbit duodenum and it activity was determined by Ellman’s assay using acetylthiocholine (ASCh) as substrate. PT-Mm concentrations (40, 80, 120 and 200 μg/mL) showed dose-dependent effect a both tonicity and amplitude of the duodenum spontaneous contractions. The effective concentration which induces 50% effect of PT-Mm (EC50) was obtained with 68.57 ± 0.89 μg/mL. The antagonist tests carried out showed a considerable reduction (90%) in the amplitudes of duodenal contractions in the presence of atropine, but with nifedipine, the contractions were completely inhibited. PT-Mm also exerted non-competitive inhibition on AChE (Vmax = 5687 mM/min and KM = 578 μM). These results suggest that PT-Mm could stimulate duodenum smooth muscle contraction because it contains anti-AChE and cholinomimetic substances which, through muscarinic receptors, increase Ca2+ mobilization from extracellular. Therefore, PT-Mm could be used as a laxative, due to its stimulating effects on duodenal contractility.Keywords: Morinda morindoides, acetylcholinesterase, duodenum, contractio

Phytochemical screening and study of comparative antibacterial activity of aqueous and alcoholic extracts of the leaves and barks of Terminalia catappa on multiresistant strains.

Objectives: In this study, methanol, ethanol and aqueous extracts of Terminalia catappa L. leaves and barks were compared for antibacterial activity against clinical (sensitive and multidrug-resistant) and ATCC strains of Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus (MRSA).Methodology and Results: The confirmation of the Enterobacteriaceae Extended-Spectrum-β-Lactamases (ESBL) producing strains was done by the double-disc synergy tests, the MRSA by disk diffusion method (cefoxitin 30 μg) according to the methods of CA-SFM, 2009. The agar dilution and broth dilution method was used for the determination of the antimicrobial parameters (MIC and MBC) on these sensitive, ESBL producing and MRSA strains. The bark extracts generally showed better activity compared to leaves extracts; but methanolic extracts of barks were the most active of all the extracts, exhibiting a broadspectrum activity. However, Staphylococcus aureus were sensitive compared to Escherichia coli and Klebsiella pneumoniae. Antibacterial activity showed value ranged from 0.52 ± 0.13 to 4.16 ± 1.04 mg/ml (MIC) and 1.56 to 10.42 ± 2.08 mg/ml (MBC). Phytochemical screening showed the presence of Flavonoids, Alkaloid, Steroid, Terpenoids, Gallic Tannins, Saponins and with the exception of the aqueous extract for Coumarins.Conclusions: The results obtained suggest that methanolic extracts of T. catappa barks can be used in treating bacterial diseases.Key words: Phytochemical Screening; Comparative Antibacterial activity; Terminalia catappa; multiresistant strains

Effects of Point Mutations in Plasmodium falciparum Dihydrofolate Reductase and Dihydropterate Synthase Genes on Clinical Outcomes and In Vitro Susceptibility to Sulfadoxine and Pyrimethamine

Sulfadoxine-pyrimethamine was a common first line drug therapy to treat uncomplicated falciparum malaria, but increasing therapeutic failures associated with the development of significant levels of resistance worldwide has prompted change to alternative treatment regimes in many national malaria control programs. METHODOLOGY AND FINDING: We conducted an in vivo therapeutic efficacy trial of sulfadoxine-pyrimethamine at two locations in the Peruvian Amazon enrolling 99 patients of which, 86 patients completed the protocol specified 28 day follow up. Our objective was to correlate the presence of polymorphisms in P. falciparum dihydrofolate reductase and dihydropteroate synthase to in vitro parasite susceptibility to sulfadoxine and pyrimethamine and to in vivo treatment outcomes. Inhibitory concentration 50 values of isolates increased with numbers of mutations (single [108N], sextuplet [BR/51I/108N/164L and 437G/581G]) and septuplet (BR/51I/108N/164L and 437G/540E/581G) with geometric means of 76 nM (35-166 nM), 582 nM (49-6890- nM) and 4909 (3575-6741 nM) nM for sulfadoxine and 33 nM (22-51 nM), 81 nM (19-345 nM), and 215 nM (176-262 nM) for pyrimethamine. A single mutation present in the isolate obtained at the time of enrollment from either dihydrofolate reductase (164L) or dihydropteroate synthase (540E) predicted treatment failure as well as any other single gene alone or in combination. Patients with the dihydrofolate reductase 164L mutation were 3.6 times as likely to be treatment failures [failures 85.4% (164L) vs 23.7% (I164); relative risk = 3.61; 95% CI: 2.14 - 6.64] while patients with the dihydropteroate synthase 540E were 2.6 times as likely to fail treatment (96.7% (540E) vs 37.5% (K540); relative risk = 2.58; 95% CI: 1.88 - 3.73). Patients with both dihydrofolate reductase 164L and dihydropteroate synthase 540E mutations were 4.1 times as likely to be treatment failures [96.7% vs 23.7%; RR = 4.08; 95% CI: 2.45 - 7.46] compared to patients having both wild forms (I164 and K540).In this part of the Amazon basin, it may be possible to predict treatment failure with sulfadoxine-pyrimethamine equally well by determination of either of the single mutations dihydrofolate reductase 164L or dihydropteroate synthase 540E.ClinicalTrials.gov NCT00951106

Evaluation of the toxicity of a methanolic total extract of Mitragyna ciliata a natural anti-malaric

Mitragyna ciliata (MYTA) is a Rubiaceae used in traditional medicine to treat malaria. Total methanolic extract of MYTA made was used for toxicological studies on laboratory mice and rats. The extractof MYTA was administered intraperitoneally. The doses ranged from 0 to 4000 mg/kg body weight (bw) (i.e.,0, 250, 500, 1000, 2000 and 4000 mg/kg bw) for acute toxicity, and from 0 to 475 mg/kg body weight (bw)(i.e., 0, 125, 250 and 475 mg/kg bw) for subacute toxicity studies. Following administration of high doses, the mice had jerky movements and died lying on their belly. The maximal tolerated dose (MTD) obtained was 500 mg/kg of bw, whereas 50% lethal dose (LD50) was 1412 mg/kg of bw. The study of the effects of MYTA on the complete blood count, blood glucose and the serum markers ((urea, uric acid, creatinine, transaminases (GOT, GPT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), creatinine phosphokinase (CPK)) ofnoble organs of rats was performed. The results obtained with the serum enzymes (GOT, GPT, ALP, CPK and LDH) showed that no significant increase of activity occurred. This indicated that the heart and liver might not have suffered damages. Besides, significant decreases were observed in the serum activities of GOT, ALP and LDH, suggesting that MYTA could have a potential hepatoprotective effect. Nevertheless, significant increases were observed in the serum concentration of urea, uric acid and creatinine at high doses. This indicates the accumulation of these metabolites in the blood, which could be due to kidney injury, leading to a decrease in renal elimination of waste

Immunomodulatory Effect of the Aqueous Extract of Erigeron floribundus (Kunth) Sch Beep (Asteraceae) Leaf in Rabbits

Purpose: The leaves of Erigeron floribundus (Kunth) Sch. Beep. or (syn: Conyza sumatrensis (Retz) E.K. Walker) (Asteraceae) are used by some traditional healers in West Africa in HIV/AIDS therapy. The purpose of this study was to assess the immune-boosting properties of the aqueous leaf extract of Erigeron floribundus (Ef) by monitoring blood markers of cellular immunity in rabbit. Methods: Two sets each of five groups (six rabbits per group) were used in this study. The groups in the first set each received intraperitoneally a single dose of Ef (25, 50, 75 or 100 mg/kg) or 0.9 % NaCl (control). The groups in the second set received methylprednisolone (15 mg/kg, MP15) and mixtures of MP15 with Ef (50, 75 or 100 mg/kg), MP15 or isoprinosine 50 mg/kg (Ip50, reference standard). Whole blood was collected in EDTA tubes from the marginal vein of the rabbit ear on Days 0, 3, 9, 15 and 21 after administration for the determination of CD4+ count by flow cytometry, and also of neutrophils and total lymphocytes in the blood. Results : Each plant extract dose tested (50, 75 and 100 mg/kg) induced a significant increase in neutrophils (p < 0.001), total lymphocytes and TCD4+ (p < 0.0001) from the 3rd to 15th day after administration, compared to control (0.9 % NaCl). Furthermore, the same test extract doses significantly reversed the immunosuppressive effect of methylprednisolone (p < 0.001) to the same extent as isoprinosine. Conclusion: The aqueous extract of the leaves of Erigeron floribundus stimulated the increase of neutrophils, total lymphocytes and TCD4+ in rabbit blood and thus provides some justification for its use in the traditional treatment of AIDS