Institute of Medical Research and Medicinal Plant Studies

Yaoundé, Cameroon

Institute of Medical Research and Medicinal Plant Studies

Yaoundé, Cameroon
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PubMed | University of Yaounde I, Institute of Medical Research and Medicinal Plant Studies, University of Botswana and University of Liège
Type: | Journal: Phytochemistry | Year: 2015

During a study on the chemistry and biological activity of Antrocaryon klaineanum Pierre, six new sterols including 4,24(28)-ergostadiene-6,7-diol (1), 6-methoxy-4,24(28)-ergostadiene-7,20S-diol (2), 6-methoxy-4,24(28)-ergostadien-7-ol (3), 20S-hydroxy-24(28)-ergosten-3-one (4), 7-hydroxy-4,24(28)-ergostadien-3-one (5), and 24(28)-ergostene-3,6-diol (6) were characterized by physical and spectroscopic means. The known steroids 7 and 8 were also isolated. The crude extract and the isolated compounds were evaluated for their ability to inhibit the 3D7 strain of Plasmodium falciparum. Compounds 2, 3, and 8 showed potent activity while that of the crude extract was moderate.

Passo Tsamo C.V.,Institute Des Science Of La Vie | Passo Tsamo C.V.,Institute of Medical Research and Medicinal Plant Studies | Herent M.-F.,Leuven Drug Research Institute | Tomekpe K.,CIRAD - Agricultural Research for Development | And 5 more authors.
Food Chemistry | Year: 2015

The present study investigated the phenolic profiles of the pulp and peel of nine plantain cultivars and compared them to those of two dessert bananas of commercial interest (Grand Nain and Gros Michel), alongside a newly created hybrid, resistant to black sigatoka disease (F568). Identification and quantification of phenolic compounds were performed by means of HPLC-ESI-HR-MS and HPLC-DAD. Hydroxycinnamic acids, particularly ferulic acid-hexoside with 4.4-85.1 μg/g of dry weight, dominated in the plantain pulp and showed a large diversity among cultivars. Flavonol glycosides were predominant in plantain peels, rutin (242.2-618.7 μg/g of dry weight) being the most abundant. A principal component analysis on the whole data revealed that the phenolic profiles of the hybrid, the dessert bananas and the pure plantains differed from each other. Plantain pulps and peels appeared as good sources of phenolics, which could be involved in the health benefits associated with their current applications. © 2014 Elsevier Ltd. All rights reserved.

Said-Mohamed R.,University Paris Diderot | Bernard J.Y.,University Paris Diderot | Bernard J.Y.,Institute National Of La Santeet Of La Recherche Medical | Ndzana A.-C.,Institute of Medical Research and Medicinal Plant Studies | Pasquet P.,University Paris Diderot
PLoS ONE | Year: 2012

Background: Recent studies suggest that early modifications in metabolic pathways and behaviour, leading to energy conservation and reduced linear growth, could represent adaptations to nutritional constraints during foetal life and infancy. Impaired fat oxidation, low resting energy expenditure and reduced physical activity, resulting from these adaptations, could facilitate fat storage and development of overweight in growth-retarded children that consume more energy-dense food. This study aims at assessing whether: (1) dual-burden preschool children (simultaneously stunted and overweight) of Yaounde (Cameroon) have low birth-weight (indicator of foetal undernutrition) and reductions in fat oxidation, resting energy expenditure (REE) and physical activity, (2) fat oxidation, REE and physical activity are associated with foetal growth. Methodology/Principal Findings: 162 children (24-72 months) were considered: 22 stunted-overweight (SO), 40 stunted (S), 41 overweight (O), and 59 non stunted-non overweight (NSNO). Nutritional status and body composition were assessed using anthropometry and multifrequency bioimpedance analysis. Fasting respiratory quotient (RQ) and REE were measured by indirect calorimetry. Physical activity was determined using accelerometers, food questionnaires were used for diet assessment and birth-weight was noted. Mean RQs and REE (weight adjusted) did not differ between stunted children (SO and S) and non-stunted children (O and NSNO). SO and S children spent more time in sedentary activities than O children (p = 0.01 and p = 0.02, respectively) and less time in moderate-to-vigorous activities than NSNO children (p = 0.05 and p = 0.04, respectively). SO children's diet was less diverse (p = 0.01) with less animal products (p = 0.006). Multiple linear regressions model revealed that birth-weight is predictive of RQ (β = 0.237, p<0.01, R 2 = 0.08). Conclusions/Significance: This study showed that growth retardation in stunted-overweight children could be associated with postnatal nutritional deficiencies. Overweight in stunted children could be associated with reduced physical activity in the context of nutrition transition. High birth-weight was a predictor of reduced lipid oxidation, a risk factor of fat deposition. © 2012 Said-Mohamed et al.

Mbongue G.Y.F.,Institute of Medical Research and Medicinal Plant Studies | Kamtchouing P.,University of Yaounde I | Dimo T.,University of Yaounde I
Andrologia | Year: 2012

Mature male albino Wistar rats (180-210g) were given aqueous extract of dry seeds of Aframomum melegueta K. Schum (Zingiberaceae) by gastric intubation during periods of 8 and 55days. This was performed in two doses: 115 and 230mgkg -1 during 8days and 115mgkg -1 during 55days. Control rats received distilled water during the same periods. The animals were sacrificed and their blood, as well as testis, epididymis, seminal vesicle and prostate were collected and analysed. Results showed a significant increase in testosterone in serum and testis, cholesterol in testis, α-glucosidase in epididymis and fructose in seminal vesicle after 8days of treatment of A. melegueta-treated rats (115 and 230mgkg -1). Results also showed that levels of cholesterol in testis, α-glucosidase in epididymis and fructose in seminal vesicle increased by 93.34%, 83.44% and 62.78%, respectively, after 55days of A. melegueta treatment. From these findings, it was concluded that the aqueous extract of A. melegueta increased the secretions of epididymis and seminal vesicle, which are accessory sex organs. © 2011 Blackwell Verlag GmbH.

Tchinda V.H.,Institute of Medical Research and Medicinal Plant Studies
The Pan African medical journal | Year: 2012

Insecticide treated net remains a tool of choice for malaria prevention in Cameroon. However, data suggests that its use by the population, especially vulnerable groups remains low. Moreover, there is a paucity of information about factors influencing its use. We sought out to identify factors associated with net use in Mfou health district, prior to distribution of long lasting insecticides treated nets (LLINs) in households. A two-stage cluster random sampling was conducted in 4 health areas with an average of 13 villages each. A total of 541 households were selected and heads interviewed using a structured household questionnaire. Data collected were entered into a database and multivariate logistic regression analyses of the association between net use and explanatory factors were performed using SPSS. Net possession and use were respectively, 59.7 and 42.6%; thus, 2 out of 5 people who spent the previous night in households, slept under a net. Factors associated with net use included: net density≥0.5 (OR=8.88, 95% CI: 6.24-12.64), age≥5 years (OR=0.37, 95%CI: 0.28-0.47), secondary education (OR=1.41, 95% CI: 1.11-1.80) compared to primary/no education, parent status (OR=3.32, 95% CI: 2.31-4.76), house construction (OR=1.37, 95% CI: 1.10-1.71) and environment characteristics (OR=1.46, 95% CI: 1.18-1.80). These data suggest that a universal coverage with one LLIN for two people should be achieved in households. Then, malaria health education should be conducted to re-enforce net use among school-aged children and adolescents, as well as older household members. Moreover, management of environment and improvement in houses construction are necessary.

Nsawir B.J.,Institute of Medical Research and Medicinal Plant Studies
Journal of Medical Sciences (Faisalabad) | Year: 2015

Scientific findings revealed that local kaolin from the Cameroon market is contaminated with lead, mercury and cadmium. This study was carried out to assess the bioavailability of these heavy metals as well as their transplacental transport and their passage into rat litters. Eighty pregnant female albino rats were fed with kaolin for 21 consecutive days and on days 0, 7, 14 and 21, four of them were sacrificed from each group by cervical dislocation to obtain blood and liver samples. Kaolin dosage was calculated per body mass considering daily human consumption range (w/w). Whole blood and liver samples were digested with concentrated nitric acid. Based on results obtained in the first study, a second experimental study consisting of 10 pregnant albino rats verified the trans-placental transport of lead and the passage of lead to litters at birth and during breastfeeding. In the first study results, values of blood lead in the control group compared to the various test groups were statistically significant. No statistical significance occurred for cadmium and mercury. The values of liver lead in the control group compared to the other test groups on average bases were statistically significant. Results of the second study showed that transplacental transport of lead occurred only for high kaolin consumption and the passage of lead to litters occurred during breastfeeding. The study revealed that lead in kaolin is bioavailable. Cadmium and mercury are absorbed from the digestive tract but are both managed at the level of the liver. © 2015, Asian Network for Scientific Information. All rights reserved.

Lonchel C.M.,University of Liège | Meex C.,University of Liège | Gangoue-Pieboji J.,Institute of Medical Research and Medicinal Plant Studies | Boreux R.,University of Liège | And 3 more authors.
BMC Infectious Diseases | Year: 2012

Background: There is no information regarding the resistance mechanisms of extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae in community setting in Cameroon. The current study aimed to determine the proportion of ESBLs in Enterobacteriaceae isolated in the community and to analyse some risk factors associated with ESBL carriage.Methods: Faecal samples were collected from 208 different outpatients and 150 healthy student volunteers between 3 January and 3 April 2009. Enterobacterial isolates resistant to third-generation cephalosporins were screened for ESBL production by the double-disk synergy test. Presumptive ESBL-producing isolates with positive synergy test were identified by Mass Spectrometry using the BioTyper MALDI-TOF. For such ESBL positive isolates, antibiotic susceptibility was determined by the Vitek 2 system. PCR and sequencing were performed for the detection of different types of ESBL genes in presumptive ESBL-producing isolates. Statistical methods were used for the univariate calculation of risk factors.Results: During the study period, a total of 358 faecal samples were analysed; 58 of such samples (16%) showed an ESBL phenotype and were confirmed by PCR. The proportion of ESBL producers in faecal carriage was statistically different between outpatients and student volunteers (23.1% vs. 6.7%: p < 0.000). According to a univariate analysis, previous use of antibiotics (ciprofloxacin) appeared to be a risk factor for ESBL carriage (p < 0.05).Escherichia coli was the species most frequently isolated among the ESBL producers in outpatients (66.7%) and student volunteers (90%). Isolates showed additional resistance to gentamicin, ciprofloxacin and trimethoprim/sulfamethoxazole but none of them was resistant to temocillin, amikacin or meropenem. Most of the strains (97%) produced a CTX-M group 1 enzymes [CTX-M-15 (98%) or CTX-M-1 (2%)] and the remaining strains produced SHV-12 enzyme (3%).Conclusions: The use of drugs such as amoxicillin, ciprofloxacin and trimethoprim/sulfamethoxazole does not seem appropriate for empirical treatment because of emerging resistance. The implementation in Cameroon or in other African countries of methods of screening ESBL-producing organisms in routine laboratories is of great importance in order for us to offer patients appropriate treatment and for infection control efforts to succeed. © 2012 Lonchel et al; licensee BioMed Central Ltd.

Lonchel C.M.,University of Liège | Melin P.,University of Liège | Gangoue-Pieboji J.,Institute of Medical Research and Medicinal Plant Studies | Assoumou M.-C.O.,University of Yaounde I | And 2 more authors.
European Journal of Clinical Microbiology and Infectious Diseases | Year: 2013

Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae have been described worldwide, but there are few reports on the carriage of these bacteria in Cameroon. In order to investigate the types of ESBLs and to analyse some risk factors associated with ESBL carriage, faecal samples were collected between 3 January and 3 April 2009 from hospitalised patients at Yaounde Central Hospital and at two hospitals in Ngaoundere, Cameroon. Enterobacterial isolates resistant to third-generation cephalosporins were screened for ESBL production using the double-disk synergy test. Polymerase chain reaction (PCR) and DNA sequencing were performed in order to find out the different types of ESBL genes in presumptive ESBL-positive isolates. During the study period, a total of 121 different patients were screened for ESBL carriage. The prevalence among these patients whose faecal samples were found to contain ESBL-producers was 55.3 % (67/121). According to a univariate analysis, hospitalisation during the previous year was found to be associated with ESBL carriage. Of the 71 bacteria isolated, Escherichia coli was predominant and represented 48 % of all isolates. ESBL characterisation revealed two types of ESBLs, CTX-M-15 (96 %) and SHV-12 (4 %). The present study emphasises the importance of screening for ESBLs in laboratories in African countries. The monitoring and detection of ESBL-producing bacteria are important in the setting up of appropriate treatment of patients and to ensure effective infection control efforts. © 2012 Springer-Verlag.

Magoue C.L.,University of Liège | Melin P.,University of Liège | Gangoue-Pieboji J.,Institute of Medical Research and Medicinal Plant Studies | Okomo Assoumou M.-C.,University of Yaounde I | And 2 more authors.
Clinical Microbiology and Infection | Year: 2013

During April 2010 and June 2010, 334 Enterobacteriaceae isolates from 590 participants (outpatients, inpatients, inpatient carers, hospital workers and members of their households) were collected from faecal samples. Based on β-lactamase pattern, origin of strains and the relationship between participants, 44 isolates of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae were selected from 44 participants (in Ngaoundere Protestant Hospital and Ngaoundere Regional Hospital, Cameroon). To determine the relatedness of bacterial strains, these isolates were fingerprinted using the automated, repetitive-sequenced-based PCR-based DiversiLab system. Subsequently, E. coli isolates that had undergone DiversiLab analysis were examined with respect to their phylogenetic group and detection of the ST131 clone to shed light on the epidemiology of these isolates in the Ngaoundere hospitals. The prevalence of faecal carriage of ESBL-producing Enterobacteriaceae among the study participants was 54.06%. According to participant groups, the prevalence of faecal carriage was also high (outpatients 45%; inpatients 67%; inpatient carers 57%; hospital workers 44%; and members of their households 46%). Analysis of the molecular epidemiology of ESBL-producing E. coli and K. pneumoniae showed a close relationship of the isolates between related and non-related individuals. In addition, DiversiLab results of E. coli identified four related isolates (4/22) from cluster III belonging to the epidemiologically important clone ST131. Our results highlight the importance of outpatients, inpatients, their carers, hospital workers and their families as reservoirs of ESBL-producing Enterobacteriaceae ©2013 European Society of Clinical Microbiology and Infectious Diseases.

Medoua G.N.,Center for Food and Nutrition Research | Nana E.S.,Center for Food and Nutrition Research | Essa'a V.J.,Center for Food and Nutrition Research | Ntsama P.M.,Center for Food and Nutrition Research | And 3 more authors.
Nutrition | Year: 2011

Objective: This study compared body composition estimates using deuterium dilution, multiple-frequency bioelectrical impedance analysis (BIA), and skinfold thickness techniques in a group of Cameroonian lactating women. Methods: Body fat, fat-free mass, and total body water in 44 Cameroonian lactating women (2.63 ± 1.31 mo postpartum) were assessed by deuterium dilution, the Siri or black-specific derived Durnin-Womerley equation, and 12 BIA-prediction equations developed in samples of subjects of white, black, black-and-white, or unspecified racial background, respectively. Results: Compared with deuterium dilution, anthropometry and BIA-based predictive equations overestimated body fat by 2.7 to 11.7 kg; thus, fat-free mass and total body water were underestimated. In all cases, the significant biases resulted in large 95% limits of agreement, yielding unacceptable potential bias at the level of the individual. However, the exclusion of suprailiac skinfold in the calculation, yielding to non-significant (P < 0.05) bias, improved the prediction of body composition in Cameroonian lactating women using the Durnin-Womersley and Siri equations. Conclusion: It is essential to adjust the Durnin-Womersley equation before using it in the Siri equation for the prediction of body composition in lactating women. Further development and cross-validation of prediction equations from BIA specific to lactating women is needed. © 2011 Elsevier Inc.

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