Antifungal potential of extracts from three plants against two major pathogens of celery (apium graveolens l.) in Cameroon

With the aim of contributing to natural control of plant pathogens, the antifungal activity of 11 extracts from 3 Cameroonian plants namely, Drypetes gossweileri, Eucalyptus tereticornis and Sida acuta was evaluated against Acremonium apii and Colletotrichum dematium, respectively causal agents of brown spot and anthracnose diseases of celery (Apium graveolens L.). The supplemented media technique was used to assess the inhibition of both fungi mycelial growth by essential oils, ethanol,hot water and cold water extracts. The essential oils exhibited the highest antifungal activity at 50 ppm with essential oil from D. gossweileri; and 6000 ppm and 7000 ppm, against C. dematium and A. apii, respectively, with essential oil from E. tereticornis. Ethanol and aqueous extracts displayed a moderate inhibitory activity with the best activity obtained from D. gossweileri ethanol extracts (90.31% and 67.53%, respectively, against A. apii and C. dematium at 10000 ppm). The fungitoxic potential of essential oils was comparative to the synthetic fungicide used as positive control. Phytochemical screening of solvent extracts revealed a diverse composition in secondary metabolites and stronger inhibitory effects were recorded with extracts rich in alkaloids, phenols, anthraquinones and saponines. These findings suggest a promising potential of essential oils and ethanol extracts for botanicals control of celery fungal pathogens

Risk factors of cervical intraepithelial lesion in Douala-Cameroon: Implications of Herpes Simplex Virus Type 2, Chlamydia Trachomatis and Treponema Pallidum

Infection with high risk oncogenic human papillomavirus (HPV) such as HPVs 16 and 18 is the main cause of cervical cancer. The objective of this study was to determine the impact of Chlamydia trachomatis, Herpes simplex virus 2 (HSV 2), Treponema pallidum and some sexual behaviour on malignant progression of cervical lesion in Douala, Cameroon. From July 2009 to January 2010, we performed routine cervical smears to 163 consenting women, who completed a questionnaire on risk factors of cervical cancer. Blood samples were obtained for each of these women and used for the detection of antibodies against Chlamydia trachomatis, HSV 2 and Treponema pallidum. Results obtained showed that 26/163 (17 LSIL and 9 HSIL) of women had abnormal cytology, 75.5% (123/163) had HSV 2 infection, 19% (31/163) infected by Chlamydia trachomatis and 4.3% (7/163) infected by Treponema pallidum. Among the LSIL-positive women 35.3% (6/17) and 94.1% (16/17) were infected with Chlamydia trachomatis and HSV 2 respectively. Among those with HSIL cytology, 22.2% (2/9), 66.7% (6/9) and 11.1% (1/9) respectively had Chlamydia trachomatis, HSV 2 and Treponema pallidum. High parity and pregnancy rate was observed among women with positive cytology. Our finding shown high rate of cervical abnormalities among women infected with HSV 2; and among those with a higher number of parities and pregnancies. These results suggest that further investigations should be made in Cameroon to access real burden of these risk factors in the progression and persistence of cervical lesion.Key words:risk factors, cervical cancer, HSV 2, Chlamydia trachomatis, sexually transmitted infections.doi: 10.4314/ajcem.v12i3.

Predictors of childhood severe malaria in a densely populated area: Douala, Cameroon

The physiopathology of malaria is complex. More understanding would be useful for a better management of the disease. This study was undertaken to describe clinical presentation and some biochemical parameters in childhood malaria in order to identify some factors of disease severity. Eighty six (86) children (0 to 15 years old) were recruited in Douala, clinical data recorded and blood sample collected. Thirty one (31) healthy children were also targeted to serve as control. Blood glucose, hemoglobin, transaminases and nitric oxide were determined by spectrophotometry. C reactive protein (CRP) was also investigated. The results confirmed that severe malaria significantly affects children under 5 years. Severe malaria was associated with hyperpyrexia and prostration. Coma, convulsions and unconsciousness were more indicative of cerebral malaria. Hemoglobin and blood glucose levels decreased significantly in severe malaria patients compared with uncomplicated malaria patients or controls (P < 0.001). On the contrary, blood transaminases and CRP levels increased significantly in malaria patients compared to controls (P < 0.001). From these results, it is clear that childhood severe malaria is associated with prostration, coma, unconsciousness, convulsions and hyperpyrexia. Low levels of haemoglobin and glycemia, as well as high levels of transaminases and CRP has been identified as predictor of malaria severity.Keywords: Childhood malaria, clinical presentation, physiopatholog

Elevated Cell-Specific Microparticles Are a Biological Marker for Cerebral Dysfunctions in Human Severe Malaria

Cerebral malaria (CM) and severe anemia (SA) are the most severe complications of Plasmodium falciparum infections. Although increased release of endothelial microparticles (MP) correlates with malaria severity, the full extent of vascular cell vesiculation remains unknown. Here, we characterize the pattern of cell-specific MP in patients with severe malaria. We tested the hypothesis that systemic vascular activation contributes to CM by examining origins and levels of plasma MP in relation to clinical syndromes, disease severity and outcome. Patients recruited in Douala, Cameroon, were assigned to clinical groups following WHO criteria. MP quantitation and phenotyping were carried out using cell-specific markers by flow cytometry using antibodies recognizing cell-specific surface markers. Platelet, erythrocytic, endothelial and leukocytic MP levels were elevated in patients with cerebral dysfunctions and returned to normal by discharge. In CM patients, platelet MP were the most abundant and their levels significantly correlated with coma depth and thrombocytopenia. This study shows for the first time a widespread enhancement of vesiculation in the vascular compartment appears to be a feature of CM but not of SA. Our data underpin the role of MP as a biomarker of neurological involvement in severe malaria. Therefore, intervention to block MP production in severe malaria may provide a new therapeutic pathway

Antimycobacterial activity of selected medicinal plants extracts from Cameroon

New drugs are highly needed to control mycobacterial infections. This study aimed at screening ethnobotanically selected plants extracted using organic solvents for their antimycobacterial activity. In vitro assays were performed on Mycobacterium smegmatis, Mycobacterium avium, Mycobacterium bovis Bacille Calmette Guerin (BCG), Mycobacterium tuberculosis and Mycobacterium ulcerans using the Resazurin Microtiter Assay. Cytotoxicity was assessed on Human lung fibroblast cells (MRC5) and bone marrow-derived macrophages (BMDM) using the MTS tetrazolium assay. The most promising extract from Annickia chlorantha stem bark (ACsbI) was tested for intracellular antimycobacterial activity against M. smegmatis using infected BMDM. Sixty crude extracts, 19 fractions, and 2 purified compounds were obtained from 19 Cameroonian medicinal plants. Results showed that crude extracts mainly inhibited BCG, while interface fractions from A. chlorantha stem bark (ACsbI) and stem (ACstI) displayed the strongest activity against M. ulcerans, with Minimal Inhibitory Concentrations (MIC) of 1.95 and 7.81 µg/ml respectively. Two compounds purified from Sorindeia juglandifolia fruits (SJfr 3.6 and SJfr 4.5) showed activity against BCG and M. ulcerans at 3.9 µg/ml and 62.5 µg/ml respectively. Finally, ACsbI showed no toxicity against MRC5 cells and BMDM and inhibited the growth of intracellular M. smegmatis. The results achieved in this investigation support the traditional to use of these plants and the need to investigate them in deeper details to be able to find alternatives for the existing antimycobacterial drugs

Antibacterial and Antioxidant Properties of the Methanolic Extract of the Stem Bark of Pteleopsis hylodendron (Combretaceae)

Pteleopsis hylodendron (Combretaceae) is used in Cameroon and West Africa folk medicine for the treatment of various microbial infections (measles, chickenpox, and sexually transmitted diseases). The antibacterial properties of the methanolic extract and fractions from stem bark of Pteleopsis hylodendron were tested against three Gram-positive bacteria and eight Gram-negative bacteria using Agar-well diffusion and Broth microdilution methods. Antioxidant activities of the crude extract and fractions were investigated by DPPH radical scavenging activity and β-carotene-linoleic acid assays. The methanolic extract and some fractions exhibited antibacterial activities that varied between the bacterial species (ID = 0.00–25.00 mm; MIC = 781–12500 μg/mL and 0.24–1000 μg/mL). The activity of the crude extract is, however, very weak compared to the reference antibiotics (MIC = 0.125–128 μg/mL). Two fractions (FE and FF) showed significant activity (MIC = 0.97 μg/mL) while S. aureus ATCC 25922 was almost resistant to all the tested fractions. In addition, the crude extract and some fractions showed good antioxidant potential with inhibition values ranging from 17.53 to 98.79%. These results provide promising baseline information for the potential use of this plant as well as some of the fractions in the treatment of infectious diseases and oxidative stress

Antiplasmodial volatile extracts from Cleistopholis patens Engler & Diels and Uvariastrum pierreanum Engl. (Engl. & Diels) (Annonaceae) growing in Cameroon

In a search for alternative treatment for malaria, plant-derived essential oils extracted from the stem barks and leaves of Cleistopholis patens and Uvariastrum pierreanum (Annonaceae) were evaluated in vitro for antiplasmodial activity against the W2 strain of Plasmodium falciparum. The oils were obtained from 500 g each of stem barks and leaves, respectively, by hydrodistillation, using a Clevenger-type apparatus with the following yields: 0.23% and 0.19% for C. patens and 0.1% and 0.3% for U. pierreanum (w/w relative to dried material weight). Analysis of 10% (v/v) oil in hexane by gas chromatography and mass spectrometry identified only terpenoids in the oils, with over 81% sesquiterpene hydrocarbons in C. patens extracts and U. pierreanum stem bark oil, while the leaf oil from the latter species was found to contain a majority of monoterpenes. For C. patens, the major components were α-copaene, δ-cadinene, and germacrene D for the stem bark oil and β-caryophyllene, germacrene D, and germacrene B for the leaf oil. The stem bark oil of U. pierreanum was found to contain mainly β-bisabolene and α-bisabolol, while α- and β-pinenes were more abundant in the leaf extract. Concentrations of oils obtained by diluting 1-mg/mL stock solutions were tested against P. falciparum in culture. The oils were active, with IC50 values of 9.19 and 15.19 μg/mL for the stem bark and leaf oils, respectively, of C. patens and 6.08 and 13.96 μg/mL, respectively, for those from U. pierreanum. These results indicate that essential oils may offer a promising alternative for the development of new antimalarials