Evaluation of acute and subacute toxicities of aqueous ethanolic extract of leaves of Senna alata (L.) Roxb (Ceasalpiniaceae)

We investigated the acute and subacute toxicities of hydro-ethanolic extract of leaves of Senna alata (L.) Roxb. in Swiss mice and Wistar albino rats. The mice were divided into 6 groups of 10 animals and each group received once by intra gastric gavages 0, 4, 8, 12, 16, 20 times 1000 mg/kg dose of extract. Distilled water served as the control. For the subacute toxicity, three groups of 10 rats (5 males and 5 females) were treated per os with distilled water (control), 500 or 1000 mg/kg of extract every 48 h for 26 days. At the end of treatment blood sample and 20% liver homogenates were collected for biochemical analyses. The results indicated that the medium lethal dose (LD50) was about 18.50 g/kg of body weight. Significant variation (P<0.05) of the body weight was observed after 26 days of treatment, in some biochemicals index of serum and 20% liver homogenates (glutathione , alkaline phosphatase (APL), aspartate aminotransferase (AST)), haematological parameters (platelet) also in the female relative weight of heart of rat. Some of parameter investigated in this study showed dose responsive. The histopatological study of the liver did not show any features after the treatment but, the extract seems to ameliorate the liver architecture.Keywords: Acute toxicity, alkaline phosphatase, hematological and histopatological stud

Can free open access resources strengthen knowledge-based emerging public health priorities, policies and programs in Africa? [version 1; referees: 2 approved]

Tackling emerging epidemics and infectious diseases burden in Africa requires increasing unrestricted open access and free use or reuse of regional and global policies reforms as well as timely communication capabilities and strategies. Promoting, scaling up data and information sharing between African researchers and international partners are of vital importance in accelerating open access at no cost. Free Open Access (FOA) health data and information acceptability, uptake tactics and sustainable mechanisms are urgently needed. These are critical in establishing real time and effective knowledge or evidence-based translation, proven and validated approaches, strategies and tools to strengthen and revamp health systems.  As such, early and timely access to needed emerging public health information is meant to be instrumental and valuable for policy-makers, implementers, care providers, researchers, health-related institutions and stakeholders including populations when guiding health financing, and planning contextual programs

Cytotoxic and Schistosomidal Activities of Extract, Fractions and Isolated Compounds from Zanthoxylum Leprieurii (Rutaceae)

Schistosomiasis is a major and chronic neglected tropical disease. The existing treatment does not kill immature schistosomes and have serious adverse side effect.  It is well known that some parasites are responsible for causing specific cancers in humans including bladder cancer from Schistosoma haematobium infection. So, novel drugs discovery is an urgent need. In this study, were evaluated in vitro the cytotoxic on human hepatocarcinoma (HepG2) and normal cells (Chang liver), and the schistosomicidal properties of crude extract, fractions and isolated compounds (1-Hydroxy-3-methoxy-N-methylacridone (1) described in this species from Cameroon for the first time, Scoparone (2), and Arborinine (3)) from powdered fruits of Zanthoxylum leprieurii (Rutaceae). All fractions: hexanic (FH), methylene chloride (FC), ethyl acetate (FA) and methanolic (FM) killed all the cercariae within 2 hours exposure and presents LC50 values between 2 and 3 μg/ml; Compounds 1 and 3 also displayed a good in vitro schistosomicidal activity against cercariae with LC50 values of 78.78 and 6.98 μg/mL, respectively. For antitumor activity compounds 1-3 and fraction FC presents good activity with IC50 values range 18.27 - 74.61 μg/mL on HepG2 cells, however most of these were more toxic on Chang cells than to HepG2 cells, with only exception for compound 2. The acridone Arborinine (3) can constitute a good lead for the research of schistosomiasis alternative therapy, and the coumarin Scoparone (2) can be used in drug design as scaffold for design new potential anticancer agents

Mycobacterium tuberculosis complex identification by polymerase chain reaction from positive culture in patients from Jamot and Mbalmayo district hospitals

mycobacteria (NTM) such as Para nitro benzoic acid (PNB) inhibition tests are often time consuming. This study aim at using PCR amplification of specific markers (hupB, IS6110, IS1081, oxyR and rpoB) for more rapid detection of MTBC in positive cultures. The study was conducted in Jamot Hospital, the largest urban treatment center for tuberculosis in Cameroon and in Mbalmayo District Hospital, a small rural district hospital. Mycobacterial culture was performed on all smear positive sputa. All positive cultures were subjected to drug susceptibility testing (DST) using the indirect proportion method. On the same  way, MTBC  were differentiated from other mycobacreia using the PNP inhibition test. DNA extracted from positive cultures was subjected to PCR amplification using specific primers (hupB, IS6110, IS1081, oxyR and rpoB). Analysis of PCR products was done by agarose gel electrophoresis. A total of 79 smear positive pulmonary tuberculosis patients were enrolled at the two sites. Drug susceptibility carried out showed that among the samples analyzed, 68 (86.08%) were susceptible to all TB drugs tested, while 11 (13.92%) were resistant to at least one of them. Resistance to streptomycin was the most frequent (8.86%), followed by resistance to isoniazid (5.06%). Identification by PCR using specific markers as hupB, IS6110, IS1081, oxyR and rpoB revealed that the mycobacterium strains belonged to the MTBC.In short, identification by PCR using these specific makers  revealed that mycobacterium species responsible for pulmonary tuberculosis in patients from Jamot and Mbalmayo District Hospital  belonged to the MTBC. Also PCR technique is more rapid compared to the PNP inhibition test. Key words: Mycobacterium tuberculosis complex, polymerase chain reaction (PCR), Cameroon

Fruits and barks extracts of Zanthozyllum heitzii a spice from Cameroon induce mitochondrial dependent apoptosis and Go/G1 phase arrest in human leukemia HL-60 cells

BACKGROUND: Zanthoxylum heitzii is a spice used to prepare several dishes and to treat tumors, syphilis, malaria, cardiac palpitations, urogenital infections in the west region of Cameroon, but the antitumor mechanisms and chemical composition are not yet investigated. This study was aimed to determine the antiproliferative effects of four extracts from the fruits and barks of Zanthoxyllum heitzii (Rutaceae) on apoptosis in human promyelocytic cells, their mechanisms and the chemical composition. The 3-(4, 5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to determine the fifty percent inhibition (IC50) concentration of the cell lines after treatment. The effect on morphology was observed using a light or fluorescence microscopy. The rate of apoptosis and the cell cycle were measured using flow cytometry (FCM). The phytochemical analysis of the extract was carried with HPLC/MS methods. RESULTS: The phytochemical analysis of the extracts indicated the presence of four known polyphenols (Syringic acid, Juglon, Luteolin and Myricetin) in both fruits and barks of Z. heitzii but in different quantities. Syringic acid and Myricetin concentrations were between 17-21 fold higher in the fruits than the stem bark. Rhamnetin (393.35 μg/mL) and Oleuropein (63.10 μg/mL) were identified only in the stem barks of Z. heitzii. Among the four extracts tested for cytotoxicity properties, only the methanol extract of fruits and barks significantly inhibited cell proliferation of HL-60 cells with IC50 value of 20 μg/mL and 12 μg/mL respectively. HL-60 cells treated with Z. heitzii extracts significantly produced reactive oxygen species (ROS) with concurrent loss of mitochondrial membrane potential (MMP). Modifications in the DNA distribution and enhanced of G1/G0 phase cell cycle arrest were observed in a concentration dependent manner. CONCLUSIONS: Polyphenols from Z. heitzii plant exert inhibitory effect on HL-60 cells through the reactive oxygen species (ROS) generation, loss of mitochondrial membrane potential and cell cycle destabilization