Antihypertensive potential of the stem bark of Canarium schweinfurthii Engl. (Burseraceae) in wistar rats: UPLC-ESI-QToF-MS/MS-based prediction of antihypertensive phytochemicals.

Ethnopharmacological relevance: Canarium schweinfurthii, also called ''Elemierd'Afrique'', is used in Cameroonian folk medicine (bark decoction) to treat patients suffering from hypertension.Aim of the study: This study aimed at evaluating the antihypertensive activities of the stem bark of Canarium schweinfurthii and identifying potential compounds present in its extract that may support or oppose its ethnomedicinial use. Materials and methods: Stem bark extract of Canarium schweinfurthii was prepared by maceration using 70 % ethanol followed by redissolution in methanol and hyphenated. Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS/MS) analysis for the detection and characterisation of secondary metabolites. Antihypertensive effects were assessed in Wistar rats after induction of hypertension with sodium chloride (NaCl) 18 % at a dose of 0.01mL/gbody weight once a day for four weeks.Hemodynamic parameters were measured weekly by anon-invasive method using the CODA system. Results: The ethanolic bark extract of C. schweinfurthii significantly inhibited the increase of blood pressure with a maximum of 23.18 % (systolic pressure, p < 0.0001), 24.77 % (diastolic pressure, p < 0.001) and 22.95 % (mean pressure, p < 0.0001) at a dose of 200 mg/kgbody weight at the 4th week, compared to agroup of Wistar rats that received only NaCl (negative control). Similarly, the extract significantly inhibited the increase in heart rate by 18.84 % (p < 0.001) at 200 mg/kgbody weight at week four. Hematological parameters did not differ significantly between the extract-treated and control groups. The UPLC-MS/MS spectrometric analysis provided evidence for the presence of several C30 terpenoids containing three or five oxygen atoms and exhibiting pentacyclic triterpenoid structures, as well as C29 terpenoids and related compounds containing nitrogen in addition to oxygen, using spectral matching, and in silico molecular formula and structure prediction. Additionally, two features were annotated with high-confidence as lignans, structurally closely related to hinokinin and dehydrocubebin through MS/MS-based in silico structure prediction using CSI: Finger ID in SIRIUS5. The lignans have been previously reported from stem bark of plants belonging to the Burseraceae family. Conclusion: The ethanolic stem bark extract of C. schweinfurthii demonstrated antihypertensive properties on the tested Wistar rats. These results support the ethnopharmacological use of C. schweinfurthii concoctions for the treatment of hypertension and suggest a protective effect against salt damage, hypothetically by the up regulation of antioxidative enzymes and/or lipids, mitigatings membrane peroxidation.

Killer-Cell Immunoglobulin-Like Receptors (KIR) in HIV-Exposed Infants in Cameroon.

The biological reason(s) behind persistent mother-to-child transmission (MTCT) of HIV (albeit at reduced rate compared to the preantiretroviral therapy era) in spite of the successful implementation of advanced control measures in many African countries remains a priority concern to many HIV/AIDS control programs. This may be partly due to differences in host immunogenetic factors in highly polymorphic regions of the human genome such as those encoding the killer-cell immunoglobulin-like receptor (KIR) molecules which modulate the activities of natural killer cells. The primary aim of this study was to determine the variants of KIR genes that may have a role to play in MTCT in a cohort of infants born to HIV-infected mothers in Yaoundé, Cameroon. We designed a cross-sectional study to molecularly determine the frequencies of 15 KIR genes in 14 HIV-exposed infected (HEI), 39 HIV-exposed/uninfected (HEU), and 27 HIV-unexposed/uninfected (HUU) infants using the sequence specific primer polymerase chain reaction (PCR-SSP) method. We found that all 15 KIR genes were present in our cohort. The frequency of KIR2DL1 was significantly higher in the unexposed (control) group than in the HIV-exposed group (OR = 0.22, P = 0.006). Stratifying analysis by infection status but focusing only on exposed infants revealed that KIR2DL5, KIR2DS1, and KIR2DS5 were significantly overrepresented among the HIV-exposed/uninfected compared to infected infants (OR = 0.20, P = 0.006). Similarly, the frequencies of KIR2DS1, KIR2DS5, and KIR2DL5 were significantly different between infants perinatally infected with HIV (HIV+ by 6 months of age) and HIV-negative infants. Our study demonstrates that KIR genes may have differential effects with regard to MTCT of HIV-1.

Diagnostic performance of a rapid whole blood-based RT-LAMP method for malaria diagnosis among apparently healthy blood donors and febrile neonates in Cameroon.

Light microscopy and rapid diagnostic tests are the two commonly used methods for malaria diagnosis that rely on the direct use of unprocessed blood samples. However, both methods do not have the level of sensitivity required for malaria diagnosis in cases of low density parasitaemia. We report here the diagnostic performance of a whole blood-based reverse transcription loop-mediated isothermal amplification method for Plasmodium falciparum malaria diagnosis in apparently healthy blood donors and febrile neonates in Cameroon. The presence of malaria parasites in whole blood samples was determined by light microscopy, antigen-based rapid diagnostic test (RDT), and by RT-LAMP using a "lyse and amplify" experimental protocol. Of the 256 blood donors tested, 36 (14.1%) were positive for malaria parasites by light microscopy, 38 (14.8%) were positive by RDT whereas 78 (30.5%) were positive by RT-LAMP. Only light microscopy and RT-LAMP detected infection among the febrile neonates (279 neonates, median age: 2 days, range: 1-9 days), with positivity rates of 8.6% and 12.2%, respectively. The overall concordance between the three methods were 75.9% for RT-LAMP and light microscopy, 75.1% for RT-LAMP and RDT, and 83.9% for light microscopy and RDT. Blood parasite densities were significantly lower in the neonates (mean: 97.6, range: 61-192 parasites/µL) compared to the blood donors (mean: 447.8, range: 63-11 000 parasites/µL). Together, the study demonstrates the usefulness of whole blood RT-LAMP for use in rapid pre-screening of blood donors and suspected neonates to avert severe consequences of P. falciparum infections.

Terminaliamide, a new ceramide and other phytoconstituents from the roots of Terminalia mantaly H. Perrier and their biological activities.

Terminaliamide (1), a new ceramide was isolated from the roots of Terminalia mantaly H. Perrier (Combretaceae) along with 4 known compounds (2-5). The structures of the compounds were elucidated using 1D and 2D NMR spectroscopy analysis and mass spectrometry. Compound 1 exhibited moderated antibacterial activity towards Staphylococcus aureus with MIC value of 62.5 µg/mL. The crude MeOH extract (TMr) highly reduced Plasmodium falciparum growth with an IC50 value of 10.11 µg/mL, while hexane fraction (F1) highly reduced Trypanosoma brucei brucei growth with an IC50 value of 5.60 µg/mL. All tested samples presented little or no in vitro cytotoxicity on HeLa cell line. The present work confirms that T. mantaly is medicinally important and may be used effectively as an antimicrobial, an antiplasmodial and an antitrypanosomial with promising therapeutic index.

Early dynamics of transmission and projections of COVID-19 in some West African countries.

The initial cases of novel coronavirus (COVID-19) were identified in most West African countries between late February and early March of 2020. But it is only after March 15, 2020 that the number of cases started rising significantly in these countries. This study analyzes the transmission dynamics of the outbreak in West Africa nearly 5 months after the effective onset. We focus on Cameroon, Ghana, Guinea and Nigeria, which are the four West African countries with the highest numbers of infected cases. We combine models of mathematical epidemiology and publicly available data to estimate the main disease transmission characteristics. In particular, we estimate the initial doubling time, the peak time, the peak rate, the final size and the short-term transmission forecasts of the COVID-19 epidemic for these countries. Policy implications for the effectiveness of control measures and for assessing the potential impact on public health in West Africa are discussed.

Compound isolation and biological activities of Piptadeniastrum africanum (hook.f.) Brennan roots.

ETHNOPHARMACOLOGICAL RELEVANCE: The dicotyledonous plant Piptadeniastrum africanum (hook.f.) Brennan (Fabaceae) is used in traditional medicine to treat various human complaints including bronchitis, coughing, urino-genital ailments, meningitis, abdominal pain, treatment of wounds, malaria and gastrointestinal ailments, and is used as a purgative and worm expeller. AIM OF THE STUDY: The present study describes the phytochemical investigation and the determination of the antimicrobial, antiplasmodial and antitrypanosomal activities of crude extract, fractions and compounds extracted from Piptadeniastrum africanum roots. MATERIALS AND METHODS: Isolated compounds were obtained using several chromatographic techniques. The structures of all compounds were determined by comprehensive spectroscopic analyses (1D and 2D NMR) and by comparing their NMR data with those found in literature. In vitro antimicrobial activity of samples was evaluated using the microdilution method on bacterial (Escherichia coli, Proteus mirabilis, Staphylococcus aureus) and fungal (Candida krusei) strains, while in vitro cell-growth inhibition activities were assessed against two parasites (Trypanosoma brucei brucei and Plasmodium falciparum strain 3D7). The cytotoxicity properties of samples were assayed against HeLa human cervical carcinoma. RESULTS: Five compounds were isolated and identified as: tricosanol 1, 5α-stigmasta-7,22-dien-3-ß-ol 2, betulinic acid 3, oleanolic acid 4 and piptadenamide 5. This is the first report of the isolation of these five compounds from the roots of P. africanum. The (Hex:EtOAc 50:50) fraction exhibited moderate antibacterial activity against P. mirabilis (MIC 250 µg/mL), while the other fractions and isolated compounds had weak antimicrobial activities. Only the EtOAc fraction presented a moderate antimalarial activity with an IC50 of 16.5 µg/mL. The MeOH crude extract and three fractions (Hexane, Hexane-EtOAc 25% and EtOAc-MeOH 25%) exhibited significant trypanocidal activity with IC50 values of 3.0, 37.5, 3.8 and 9.5 µg/mL, respectively. CONCLUSION: These results demonstrated a scientific rational of the traditional uses of P. africanum and indicate that this plant should be further investigated to identify some of the chemical components that exhibited the activities reported in this study and therefore may constitute new lead candidates in parasiticidal drug discovery.

Tuberculosis treatment outcome and its associated factors among people living with HIV and AIDS in Fako Division of Cameroon.

BACKGROUND: Tuberculosis (TB) and HIV co-infection challenges treatment and worsens the outcome of TB treatment. This study aimed to assess the outcome of TB treatment and factors facilitating treatment success among people living with HIV/AIDS in Fako Division of the South West Region of Cameroon. METHODS: A hospital-based retrospective cohort study was conducted by manually reviewing medical records of HIV/TB co-infected patients from January 2010 to September 2017. A structured data collection form was used to review the medical records of HIV patients co-infected with TB aged 10 years and older. Patients with incomplete files were dropped from the study. Treatment success was defined as the sum of patients who were declared cured and those who had completed treatment, as per the World Health Organization's recommendations. Data were analyzed using Statistical Package for Social Sciences version 21. Bivariate and multivariate logistic regression model was carried out to identify factors facilitating successful TB treatment outcome. Significance was obtained through adjusted odds ratio with its 95% confidence interval and a p<0.05. RESULTS: A total of 2,986 files were reviewed but 2,928 (98.1%) were retained. Out of the 2,928 medical files of adult TB patients reviewed, 1,041 (35.6%, [95% CI 33.8%-37.3%]) were HIV/TB co-infected. The 1,041 co-infected patients had a mean age of 37.07 (SD of10.02) years and 56.3% were females. The treatment outcome of TB patients were 795(76.4%) cured, 23(2.2%) treatment completed, 99(9.5%) were lost to follow-up, 16 (1.5%) failed, 72(6.9%) died and 36(3.5%) transferred out. A successful treatment outcome was achieved in 818(78.6%,[95% CI: 76.0%-81.0%]) patients. Being a female [COR 1.61, 95% CI: 1.19-2.17, p = 0.002], receiving TB treatment in 2014 [COR 2.00, 95% CI: 1.11-3.60, p = 0.021] and 2015 [COR 2.50, 95% CI: 1.39-4.50, p = 0.002], having relapsed TB infection [COR 0.46, 95% CI: 0.23-0.93, p = 0.031], receiving ART [COR 1.95, 95% CI: 1.28-2.97, p = 0.002] and Cotrimoxazole [COR 2.03, 95% CI: 1.12-3.66, p = 0.019] were factors significantly associated with successful treatment. After adjusting for confounders, successful treatment outcome were associated with being a female [AOR 1.6; 95% CI: 1.21-2.22, p = 0.001], diagnosis of TB in 2014 [AOR 1.90; 95% CI: 1.04-3.45, p = 0.036] and 2015 [AOR 2.43; 95% CI: 1.33-4.43, p = 0.004]. CONCLUSION: There is a high TB treatment success rate among HIV/TB co-infected patients in our setting, although below the target set by the WHO. Specific interventions aimed at enhancing patient outcomes are recommended.

Comparative evaluation of a rapid diagnostic test, an antibody ELISA, and a pLDH ELISA in detecting asymptomatic malaria parasitaemia in blood donors in Buea, Cameroon.

BACKGROUND: In malaria endemic areas, infected blood donors serve as a source of infection to blood recipients, which may adversely affect their prognosis. This necessitates the proper screening of blood to be used for transfusion in these areas. The purpose of this study was to determine the prevalence of malaria parasitaemia in blood donors in Buea, Cameroon, and to evaluate the performance of a rapid diagnostic test (RDT), a malaria antibody enzyme-linked immunosorbent assay (ELISA), and a Plasmodium lactate dehydrogenase (pLDH) ELISA in the detection of asymptomatic malaria parasitaemia in the target population. METHODS: In a prospective study conducted between September 2015 and June 2016, 1 240 potential blood donors were enrolled. The donors were screened for malaria parasites using Giemsa microscopy (GM) and a RDT. A sub-sample of 184 samples, comprising 88 positive and 96 negative samples, were selected for the evaluation of the pLDH ELISA and the antibody ELISA. The chi-square test and correlation analysis were performed as part of the statistical analyses. The statistical significance cut-off was set at P < 0.05. RESULTS: The prevalence of malaria parasitaemia in this study was found to be 8.1% (95% CI: 6.6 - 9.7). The prevalence was not observed to be dependent on the age or sex of the participants. The RDT had a sensitivity (88.0%), specificity (99.1%), and negative predictive value (99.0%) higher than the ELISAs. The performance of the pLDH ELISA, which demonstrated the highest positive predictive value (91.6%), was generally comparable to the RDT. The sensitivity was lowest with the antibody ELISA (69.9%), which also demonstrated the highest false positive and false negative rates. The detection threshold for the pLDH (three parasites/µl) was lower compared to the RDT (50 - 60 parasites/µl). Non-significant positive correlations were observed between the parasite density and the pLDH titers and malaria antibody titers. CONCLUSIONS: Overall, the RDT and the pLDH ELISA demonstrated a perfectly correlated agreement with GM, meanwhile the antibody ELISA demonstrated a substantially correlated agreement with GM. The pLDH is therefore recommended for mass screening of blood (to detect malaria parasitaemia) for transfusions in the study area. However, where this is not feasible, an RDT will suffice.

Intestinal parasitic infections in relation to CD4(+) T cell counts and diarrhea in HIV/AIDS patients with or without antiretroviral therapy in Cameroon.

BACKGROUND: Intestinal parasitic infections (IPI) are a major public health concern in HIV/AIDS patients particularly in resource-limited settings of Sub-Saharan Africa. Studies investigating the relationship between intestinal parasitic infections and CD4(+) T cell counts and diarrhea in HIV/AIDS patients with or without antiretroviral therapy in the region are not readily available hence the need to perform this study. METHODS: In a comparative cross-sectional study involving 52 pre-ART and 248 on-ART HIV patients. Stool samples were collected and analysed for intestinal parasites by wet and iodine mounts, Kato-Katz, formol ether, modified field staining, and modified Ziehl-Neelsen staining techniques. Blood samples were collected and analysed for CD4(+) T cell counts by flow cytometry. A pre-tested semi-structured questionnaire was used to collect data on socio-demographic and clinical presentation. Data were analysed using STATA version 12.1. Statistical tests performed included the Pearson Chi-square, logistic regression and student's t-test. P < 0.05 was considered to be statistically significant. RESULTS: The prevalence of intestinal parasitic infections in pre-ART and on-ART was 84.6% and 82.3% respectively with no significant difference observed with respect to age (p = 0.06), and gender (p = 0.736). All the opportunistic parasites including Cryptosporidium parvum, Cyclospora cayetanensis, Isospora belli and Microsporidium spp. were isolated from both groups, with only Microsporidium spp. significantly associated with CD4(+) T cell counts below 200 cells/µl in pre-ART (p = 0.006) while Cryptosporidium parvum, Microsporidium spp. and Isospora belli were associated with counts below 200 cells/µl in on-ART. Cryptosporidium parvum was significantly associated with diarrhea in pre-ART (p = 0.025) meanwhile it was significantly associated with diarrhea in on-ART (p = 0.057). The risk of diarrhea was highest in patients with CD4(+) T cell counts below 200 cells/µl (COR = 10.21, p = 0.000) for both pre- and on-ART treatment. CONCLUSION: A very high prevalence of intestinal parasitic infections was observed, which did not differ with respect to ART status. All known opportunistic parasites were isolated in both pre-ART and on-ART patients. Low CD4(+) T cell count may appear to be a factor for intestinal parasitic infections and development of diarrhea. Regular screening and treatment of intestinal parasitic infections is very vital in improving the overall quality of care of HIV/AIDS patients.

In vitro antimicrobial and anti-proliferative activities of plant extracts from Spathodea campanulata, Ficus bubu, and Carica papaya.

CONTEXT: African medicinal plants represent a prominent source of new active substances. In this context, three plants were selected for biological investigations based on their traditional uses. OBJECTIVE: The antimicrobial and anti-proliferative features of three plants used for medicinal purpose were evaluated. MATERIALS AND METHODS: The antimicrobial activities of methanol extracts of Ficus bubu Warb. (Moraceae) stem bark and leaves, of Spathodea campanulata P. Beauv. (Bignoniaceae) flowers, as well as those of Carica papaya Linn. (Caricaceae) latex, were determined using the microbroth dilution method against a set of bacteria and fungi pathogens including: Enterococcus faecalis, Staphylococcus aureus, S. saprophyticus, S. epidermididis, Escherichia coli, Klebsiella pneumonia, Salmonella typhimurium, Candida albicans, and Trichophyton rubrum. The tested concentrations of extracts ranged from 2500.0 to 2.4 µg/mL and MIC values were evaluated after 24 h incubation at 37 °C. Subsequently, MTT assay was used to estimate anti-proliferative activity of these methanol extracts and of F. bubu latex on three human cancer cell lines (U373 glioblastoma, A549 NSCLC, and SKMEL-28 melanoma). RESULTS: The methanol extract of F. bubu stem bark exhibited the highest antimicrobial activity against C. albicans with a MIC value of 9.8 µg/mL, while the F. bubu latex and the methanol extract of F. bubu leaves induced significant anti-proliferative activity against lung (IC50 values of 10 and 14 µg/mL, respectively) and glioma (IC50 values of 13 and 16 µg/mL, respectively) cancer cells. CONCLUSION: These results indicate that effective drugs could be derived from the three studied plants.

Highly active antiretroviral therapy and dyslipidemia in people living with HIV/AIDS in Fako Division, South West Region of Cameroon.

BACKGROUND: The advent of HAART has been associated with a profound reduction in morbidity and mortality from HIV/AIDS. However, side effects and toxicities associated with HAART may lead to an increased risk for cardiovascular diseases. The aim of this study was to determine the prevalence of dyslipidemia and determining factors of derangements in lipid profile associated with the use of HAART regimens in people living with HIV/AIDS in Fako Division of the South West Region of Cameroon. METHODS: This cross-sectional study was conducted between March and August 2014. Lipid profile was determined after overnight fast and dyslipidemia diagnosed according to the US National Cholesterol Education Program III criteria. Socio-demographic characteristics were also collected using a questionnaire. Data was analyzed using STATA; chi-square test, student's t-test, ANOVA and logistic regressions were computed. RESULTS: Two hundred and nine participants were recruited including 157 (75.1 %) on HAART and 52 (24.9 %) HAART-naïve. Antiretrovirals were drugs containing two nucleoside backbones (zidovudine/ /lamivudine/tenofovir) with either a non-nucleoside (nevirapine/efavirenz) or a protease inhibitor (lopinavir). No patient was treated with statins. Their mean age was 43.4 (±11.0) years. The mean CD4(+) T cell count was 425 (±281) cells/µl after mean duration of HIV infection of 54.8 (±43.9) months and mean duration on ART of 63.7 (±41.4) months. The prevalence of total cholesterol (≥ 200 mg/dL) was 51.0 % in patients on HAART and 9.6 % pre-HAART patients (p < 0.0001), whereas LDL-cholesterol ≥ 130 mg/dL occurred in 36.9 % and in 7.7 % respectively, (p = 0.0001). Receiving HAART (adjusted odds ratio =6.24, 95 % CI: 2.33-17.45, p < 0.0001) and HIV duration of 42 months and more (aOR = 2.26, 95 % CI: 1.16-4.42, p = 0.017) were independently associated with total cholesterol ≥ 200 mg/dL. Receiving HAART (aOR = 5.28, 95 % CI: 1.17-16.32, p = 0.004) was independently associated with raised LDL-cholesterol values. The adjusted odds ratio (95 % CI) of BMI ≥ 25.0 kg/m(2) versus BMI < 25.0 kg/m(2) was 3.25 (1.44-7.34) for triglycerides ≥ 150 mg/dL. CONCLUSION: HAART regimens were significantly associated with atherogenic lipid profile. Lipid profile should be monitored in HIV/AIDS patients on therapy so that any negative effects of HAART are optimally managed.