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Conclusion: Based on the results obtained, the P. densinervia hydroethanolic leaf extract possesses a better antioxidant and antiadipogenic activities than the bark extract.

Abstract A new diazo derivative of a pyrrolidine-2,5-dione (8) fused at position-3,4 to a dibenzobarrelene backbone has been prepared by coupling the previously reported N-arylsuccinimid (5) precursor with aryldiazonium ion of aniline. The initial step of the reaction involved the preparation of the intermediate 9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboxylic anhydride (3) through [4 + 2]-cycloaddition between anthracene and maleic anhydride in refluxing xylene which was then condensed with para-aminophenol to give compound 5. Compounds 5 and 8 were characterized by their physical, elemental, and spectroscopic data. 2D-NMR (COSY, HSQC, and HMBC) techniques were used to confirm the structure of compound 5. Compounds 5 (MIC = 32–128 μg/mL) and 8 (MIC = 16–256 μg/mL) along with the precursor 3 (MIC = 64–128 μg/mL) displayed moderate to low antimicrobial activities against selected bacterial and fungal species when compared with those of nystatin (MIC = 0.50–2 μg/mL) and ciprofloxacin (MIC = 0.50–16 μg/mL) used as reference drugs. Graphical Abstract

In an increasingly interconnected world, with the devastating effects of climate changes and humanitarian crises, pandemics and emerging infectious diseases are more likely to become our daily reality. When it comes to health care, sub-Saharan Africa faces more challenges than most other regions of the world, including lack of funds, precarity and poor infrastructures. Yet, these areas are most often on the front lines of infectious threats.

Abstract Brucellosis is one of the world's most widespread bacterial zoonoses caused by Brucella. It leads to considerable economic losses as a result of low productivity of infected animals and the long debilitating illness in humans. Despite its impact on human and animal health, little attention has been paid on Brucella infections in domestic animals. It is in this light that the prevalence of Brucella antibodies was determined in domestic animals with the overarching goal of improving our knowledge on brucellosis in southern Cameroon. During cross‐sectional studies conducted from December 2016 to August 2018 in five sites of southern Cameroon, blood samples were collected in cattle, sheep, goat, pig and dog. Plasma was obtained from each blood sample and Brucella antibodies were detected using the Rose Bengal test and the enzyme‐linked immunosorbent assay (ELISA). From 1873 animals that were sampled, the overall prevalence of Brucella antibodies using Indirect enzyme‐linked immunosorbent assay (i‐ELISA) was 6.35% (118/1873): 9.12% (78/855) in cattle; 8.04% (30/373) in sheep; 6.06% (2/33) in dog, 1.87% (3/160) in pig and 1.1% (5/452) in goat. Between animal species (p‐value

Dietary bioactive compounds from natural sources (e.g., herbal medicines, foods) are known to potentially suppress acute or chronic inflammation and promote the effectiveness of treatment to reduce the harmful effects of gastritis alone or in combination. In this regard, we have characterized four Cameroonian spice extracts, namely Aframomum citratum, Dichrostachys glomerata, Tetrapleura tetraptera, and Xylopia parviflora through reverse phase-high-performance liquid chromatography (RP-HPLC), ultra-performance liquid chromatography-electrospray ionization high-resolution mass spectrometry (UPLC-ESI-HRMS/MS), and Fourier transform infrared spectroscopic (FTIR) analyses and investigated their antioxidant and synergistic anti-inflammatory activities in human gastric adenocarcinoma (AGS) and gastric epithelial (GES-1) cells. The extracts showed a high amount of total phenolic (TPC: 150–290 mg gallic acid equivalents (GAE)/g of extract) and flavonoid content (TFC: 35–115 mg catechin equivalents (CE)/g of extract) with antioxidant properties in a cell-free system (1,1-Diphenyl-2-picryl-hydrazyl (DPPH) half maximal inhibitory concentration (IC50s) ≤ 45 µg/mL; 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) half maximal inhibitory concentration (IC50s) ≤ 29 µg/mL. The extracts in combination (MIX) exert a synergistic beneficial effect (combination index (CIs) < 1 and dose reduction index (DRIs) > 1) on inflammatory markers (interleukin (IL)-8 and -6 release, and nuclear factor kappa B (NF-κB) driven transcription) in human gastric epithelial cells, which may result from the presence of phenolic compounds (phenolic acids, flavonoids) or other compounds (protein, lipid, aromatic, and polysaccharide compounds) tentatively identified in the extracts. The general findings of the present study provide supporting evidence on the chemical composition of four Cameroonian dietary plants and their significant synergistic inhibitory activities on inflammatory markers of gastric epithelial cells.

Psychotria densinervia hydro-ethanolic leaf extract (PHELE) and bark extract (PHEBE) were evaluated for antioxidant, anti-inflammatory, and inhibition of digestive enzymes activities. The antioxidant activity was characterized by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP), total phenolic content (TPC), and total flavonoid content (TFC) assays. The anti-inflammatory activity was characterized by protein denaturation and antiproteinase tests, while the inhibition of the enzymes was assessed using α-amylase, α-glucosidase, lipase, and cholesterol esterase activities. PHELE presented low (p

Abstract Background Ticks and tick-borne diseases are a major impediment to livestock production worldwide. Cattle trade and transnational transhumance create risks for the spread of ticks and tick-borne diseases and threaten cattle production in the absence of an effective tick control program. Few studies have been undertaken on cattle ticks in the Central African region; therefore, the need to assess the occurrence and the spatial distribution of tick vectors with the aim of establishing a baseline for monitoring future spread of tick borne-diseases in the region is urgent. Results A total of 7091 ixodid ticks were collected during a countrywide cross-sectional field survey and identified using morphological criteria. Of these, 4210 (59.4%) ticks were Amblyomma variegatum, 1112 (15.6%) Rhipicephalus (Boophilus) microplus, 708 (10.0%) Rhipicephalus (Boophilus) decoloratus, 28 (0.4%) Rhipicephalus (Boophilus) annulatus, 210 (3.0%) Hyalomma rufipes, 768 (10.8%) Hyalomma truncatum, and 19 (0.3%) Rhipicephalus sanguineus. Three ticks of the genus Hyalomma spp. and 33 of the genus Rhipicephalus spp. were not identified to the species level. Cytochrome c oxidase subunit 1 (cox1) gene sequencing supported the data from morphological examination and led to identification of three additional species, namely Hyalomma dromedarii, Rhipicephalus sulcatus and Rhipicephalus pusillus. The finding of the invasive tick species R. microplus in such large numbers and the apparent displacement of the indigenous R. decoloratus is highly significant since R. microplus is a highly efficient vector of Babesia bovis. Conclusions This study reports the occurrence and current geographical distribution of important tick vectors associated with cattle in Cameroon. It appears that R. microplus is now well established and may be displacing native Rhipicephalus (Boophilus) species, such as R. decoloratus. This calls for an urgent response to safeguard the livestock sector in western central Africa.

Abstract Background Dengue fever is the world’s fastest spreading mosquito borne viral infection. It is prevalent throughout both subtropical and tropical region, and affects over 128 countries. Dengue virus (DENV) infection poses a serious global public health challenge to three billion people, resulting in approximately 200 million cases of morbidity and 50,000 cases of mortality annually. In Cameroon like in most sub-Saharan African countries, DENV infection occur concurrently with other infectious diseases whose symptoms often overlap, rendering differential diagnosis challenging. This study aims at determining the frequency of acute dengue among febrile children under 15 years attending hospitals in some areas of Cameroon. Methods A total of 961 children under the age of 15 were recruited in a cross-sectional study using systematic sampling technique and by selecting each subject out of the three. The study was conducted in 10 public health centers in Cameroon. Demographic data and risk factors of the subjects were obtained using well-structured questionnaires. Dengue virus NS1 antigen, IgM and IgG were analysed using a Tell me fast® Combo Dengue NS1-IgG/IgM Rapid Test. An in-house ELISA test for dengue specific IgM antibody was equally performed for confirmation. Descriptive statistical analysis was performed using Graph pad version 6.0. Results A prevalence of 6.14% acute dengue virus infection was observed among children with febrile illness with a significant difference (p = 0.0488) between males (4.7%) and females (7.7%). In addition, children who reportedly were unprotected from vectors, showed a comparatively higher prevalence of the disease seropositivity than those practicing protective measures. Conclusion DENV infection therefore is an important cause of fever among children in Cameroon. Thus, there is a need to include differential screening for DENV infections as a tool in the management of fever in children in the country.

Background Hepatitis B virus (HBV) infection is a major public health issue worldwide, with about 257 million people reported to be chronic carriers by the WHO fact sheet updated in 2018. HBV can be contracted via direct contact with infected body fluid and infection is almost always asymptomatic. Although healthcare workers (HCWs) are at high risk of HBV infection, little is known about the prevalence of the various HBV markers among HCWs in Cameroon. The present study was taken to evaluate the prevalence of different HBV serological markers among HCWs in the North-West Region of Cameroon.Methods This cross-sectional hospital-based study was carried out between April and September 2017 during which 395 HCWs were recruited. The serum of the HCWs were tested for the presence of HBV core antibody, hepatitis B surface antibody, hepatitis B e antibody and hepatitis B surface antigen using Monalisa ELISA kits produced by BIO-RAD laboratories. Data were analysed using SPSS V.20.0.Results Among the 395 participants, 270 (68.4%) of them were females, 187 (47.3%) had been exposed to HBV, 145 (36.7%) had resolved the infection, 42 (10.6%) were current HBV carriers, 10 (2.5%) were infective, 36 (9.1%) were vaccinated and 172 (43.5%) were still susceptible. Exposure to HBV, past infection and susceptibility were significantly associated with age while the rate of vaccination was significantly associated with the job of the HCW in the health facilities.Conclusion The prevalence of HBV exposure and infection among HCWs obtained in this study was high while the level of vaccination in this at-risk population was low. Adequate steps should be taken to sensitise this population on HBV and the vaccination procedure.

INTRODUCTION: The risk of dengue virus or its antibodies which can be transmitted through blood transfusion by asymptomatic individuals infected, has been a major concern all over the world. Dengue is an endemic disease in sub-Saharan Africa, particularly in Cameroon. The purpose of this study is to determine the frequency of dengue virus (DENV) infection among potential blood donors at Yaounde Jamot Hospital.

Introduction Hepatitis B virus (HBV) is a bloodborne virus which can be transmitted via percutaneous and mucocutaneous exposure to infected body fluid. Healthcare workers (HCWs) who are continuously exposed to different body fluids are at an increased risk of contracting and transmitting this virus. It is thus important to evaluate the knowledge and attitude of HCWs towards HBV and the prevalence of HBV infection among them.Methods This cross-sectional study was carried out between April and September 2017. Overall, 398 HCWs were recruited for this study. Knowledge on the route of HBV transmission and attitude towards HBV were evaluated using a well-structured questionnaire. Hepatitis B surface antigen (HBsAg) positivity was obtained using the Monolisa HBsAg ULTRA kit (Bio-Rad). Data were analysed using SPSS V.20.Results Among the HCWs who participated in this study, 338 (84.9%) had heard of HBV, and 269 (67.6%) of them had adequate knowledge on the route of HBV transmission. Medical doctors were the most knowledgeable among biomedical workers and students (76.5%). The rate of stigma was highest among nurses (87, 38.8%). The prevalence of HBsAg positivity was high (42, 10.6%) given that there is an efficient and available vaccine. Overall, over 70% of HCWs invited to participate in this study responded.Conclusion Knowledge on the route of HBV transmission was fair, and the level of stigmatisation of HBV-infected patients and the prevalence of HBV infection were high in this study. A sensitisation campaign should be carried out to educate HCWs on HBV, thus reducing the level of stigma associated with HBV as well as the probability of contracting HBV as a nosocomial infection.

Objective: To determine inhibitory activity of methanolic leaf extract of Piper umbellatum and Persea americana (P. americana) (traditionally used in Cameroon against diabetes) on α -glucosidase, β -glucosidase, maltase-glucoamylase, aldose reductase and aldehyde reductase activities, enzymes involved in starch digestion or diabetic complications. Methods: The methanol extracts from Piper umbellatum and P. americana were prepared by maceration. To assess relative efficacy of these extracts, the determination of concentrations that were needed to inhibit 50% of enzyme activity was done, whereas, gas chromatography-mass spectrum was used to identify components from extracts that may be responsible for the activities. Results: The tested extracts strongly inhibited α -glucosidase, maltase-glucoamylase, aldose reductase and aldehyde reductase activities with IC50 ranging from (1.07 ± 0.03) to (31.77 ± 1.17) μg/mL. Among the tested extracts, P. americana was the most active against sensitive enzymes (IC50 of 1.07 ± 0.03 to 15.63 ± 1.23). But, none of the extracts showed interesting inhibitory effect against β -glucosidase as their percentage inhibitions were less than 16%. From gas chromatography-mass spectrum analysis, 10 and 8 compounds were identified in Piper umbellatum and P. americana extracts respectively, using NIST library 2014. Conclusions: Results of this study provide the scientific credential for a prospective usage of these plants to treat diabetes.

This study falls within the search for alternative solutions to problems related to diseases associated with oxidative stress. It involved the evaluation of antioxidant activities extracts from thirteen antibacterial Cameroonian food plants, namely, P. nigrum, A. cruentus, L. sativa, S. edule, S. nigrum, V. amygdalina, A. hybridus, V. hymenolepis, L. capensis, M. esculenta, C. melo, T. occidentalis, and T. triangulare. The thirteen plant extracts with a broad spectrum of antibacterial activity all showed total reducing powers ranging between 2.41 and 27.81 AAE (mg ascorbic acid equivalents per gram of dried extract) and total phenol contents between 2.65 and 35.03 GAE (mg of gallic acid equivalents per gram of dried extract) of dry extract. Except for extracts of L. capensis, the other 12 extracts showed flavonoid contents ranging between 0.29 and 5.99 RE (rutin equivalents per gram of dried extract). All 13 plant extracts also showed free radical scavenging activity against DPPH· with IC50 ranging between 1.65 and 310.52 μg/ml, while 12 of these extracts exhibited inhibitory activity against NO· radical (IC50 ranging from 19.77 to 157.72 μg/ml). Statistically insignificant positive correlations (p>0.5) were found between antibacterial activities of these plants and their antioxidant activities. The different results of this study provide scientific evidence for the use of these antibacterial food plants in the control of different conditions associated with oxidative stress.

Diagnosis of tuberculosis still faces a lot of challenges and is one of the priorities in the field of tuberculosis management. Deciphering the complex tuberculosis pathogenicity network could provide biomarkers for diagnosis. We discussed the distribution of HLA-B17, -DQB and -DRB together with QuantiFERON test results in tuberculosis infection. A case control study was done during which a total of 337 subjects were enrolled comprising 227 active tuberculosis (ATB), 46 latent tuberculosis infection (LTBI) and 64 healthy controls (HC). Sequence-specific primer polymerase chain reaction and immune epitope database were used to genotype samples and determine the epitope binding ability of the over-represented alleles respectively. QuantiFERON test was done according to manufacturer's instructions. The peptides HLA-B*5801 and HLA-DRB1*12 and the peptides HLA-B*5802 and HLA-DQB1*03 were found to be associated with latent tuberculosis while the haplotypes DRB1*10-DQB1*02 and DRB1*13-DQB1*06 were found to be associated with active tuberculosis (All p-values≤0.05). The association of HLA-B*5801 and HLA-B*5802 with latent tuberculosis was linked to their ability to bind or not mycobacterial antigens. DRB1*10-DQB1*02 haplotype was found to be over-represented in LTBI compared to ATB (p-value = 0.0015) while DRB1*13-DQB1*06 was found to be under-represented in LTBI compared to ATB (p-value = 0.0335). The DRB1*10-DQB1*02 haplotype was only found in the LTBI when compared with the ATB group. The present study suggests the following algorithm to discriminate LTBI from ATB: QuantiFERON+ and DRB1*10-DQB1*02 haplotype + may indicate LTBI; QuantiFERON+ and DRB1*10-DQB1*02 haplotype - may indicate ATB.

INTRODUCTION: A routine diagnosis of dengue virus (DENV) infection is not usually conducted in hospitals. Because symptoms overlap, many potential febrile illnesses due to DENV may be confused for malaria, typhoid or paratyphoid (enteric) fever. The absence of data on DENV exposure rates among children attending health facilities could undermine management of this disease. This study aimed to investigate the seroprevalence of dengue virus infection in children presenting febrile illness in some public health facilities in Cameroon. METHODS: a cross-sectional study was performed in children ≤ 15 years attending seven urban and three semi-urban public hospitals of Cameroon. From each volunteer, 2ml of whole blood was collected and tested for dengue virus IgM, malaria (Pf/Pan antigens) and enteric fever (Typhoid IgM) using rapid diagnostic tests (RDT); in order to allow the healthcare workers to quickly put the positive cases under appropriate treatment. Positive cases of dengue virus infection were confirmed by indirect ELISA. Data analysis were performed using the statistical package for social sciences software, version 22.1. RESULTS: a total of 961 children were enrolled in the study and 492 (51.2%) were infected with at least one of the three pathogens. Overall, DENV IgM seroprevalence among febrile children was 14.4% (138/961). About 390 (40.6%) and 22 (2.3%) had malaria (Pf/Pan Ag) and enteric fever (Typhoid IgM) respectively. Co-infection with dengue virus was found in 51 (5.3%) participants. The dengue virus IgM seroprevalence was higher in Bankim (19.3%), Ntui (18.3%) and Douala (18.2%). CONCLUSION: dengue virus infection seroprevalence appears to be low in children presenting with febrile illness in the studied health centres in Cameroon but call for more attention and research to further characterise the circulating strains of the dengue virus.

Objective/background: The latest incidence of tuberculosis (TB) (per 100,000 people) in Cameroon was 243.00 as of 2011. Over the past 21 years, the value for this indicator has fluctuated between 112.00 in 1990 and 320.00 in 2003. Worldwide, this incidence has also increased, bringing back TB as a reemerging disease. On the same note, resistance to anti-TB drugs has increased, urging the search for new molecules. Methods: This study was carried out to evaluate the antimycobacterial activity of six medicinal plants on the virulent strain, H37Rv, using the microplate alamarBlue assay. Mycobacterium tuberculosis (H37Rv strain) was incubated with decreased concentrations of six plant extracts, ranging from 250 μg/mL to 31.25 μg/mL. After 7days of incubation at 37 °C, the effects of these plant extracts on the viability of the mycobacteria were evaluated. For each plant extract, the minimal inhibitory concentration was determined. Results: The results showed that the compounds MBC1, MBC24, MBC68, MBC81, MBC117, and MBC118 were the best candidates with minimal inhibitory concentrations of 31.25, 62.5, 125, 62.5, and 125 μg/mL, respectively. Conclusion: These results confirm and validate the traditional use of these plants to treat respiratory diseases, which could be good sources and alternatives of plant metabolites for anti-TB-drug development.

Poly(3-hydroxypropionate) (P3HP) is a thermoplastic with great compostability and biocompatibility, and can be produced through several biosynthetic pathways, in which the glycerol pathway achieved the highest P3HP production. However, exogenous supply of vitamin B12 was required to maintain the activity of glycerol dehydratase, resulting in high production cost. To avoid the addition of VB12, we have previously constructed a P3HP biosynthetic route with β-alanine as intermediate, and the present study aimed to improve the P3HP production of this pathway. L-aspartate decarboxylase PanD was found to be the rate-limiting enzyme in the β-alanine pathway firstly. To improve the pathway efficiency, PanD was screened from four different sources (Escherichia coli, Bacillus subtilis, Pseudomonas fluorescens, and Corynebacterium glutamicum). And PanD from C. glutamicum was found to have the highest activity, the P3HP production was improved in flask cultivation with this enzyme. To further improve the production, the host strain was screened and the culture condition was optimized. Under optimal conditions, production and content of P3HP reached to 10.2 g/L and 39.1% (wt/wt [cell dry weight]) in an aerobic fed-batch fermentation. To date, this is the highest P3HP production without VB12.

Background: Crinum purpurascens is a herbaceous plant belongingto the Amaryllidaceae family. We aimed to evaluatethe antisalmonellal properties of the leaf extracts and fractionsof C. purpurascens, and the toxicity of the most active extract.Methods: Three extracts and three fractions were prepared fromthe leaves of Crinum purpurascens Herb. (Amaryllidaceae) andtested for their antisalmonellal activities and toxicity profile. Theantibacterial activity was determined using agar diffusion, agardilution, and broth dilution techniques. Phytochemical screeningof the various extracts and fractions was performed. The toxicityprofile of the CH2Cl2/MeOH (1:1) extract was studied.Results: All the extracts and fractions, except hexane fraction,showed antimicrobial activity against Salmonella typhi, Salmonellaparatyphi A and Salmonella paratyphi B. TheCH2Cl2/MeOH (1:1) extract showed the highest activity. Theminimum inhibitory concentration values were 2.50 mg/mlagainst S. typhi, and 1.88 mg/ml against S. paratyphi A and S.paratyphi B. The minimum bactericidal concentration values were7.50 mg/ml against S. typhi and 3.75 mg/ml against S. paratyphiA and S. paratyphi B. Mice administered high doses of extractexhibited reduced reaction to noise, locomotion, reactivity andreaction to pinch, and losses in body weight. Additionally, the ratsthat received high doses of the extract showed increase in liver,spleen and kidney to body weight ratios, and decrease in total proteinconcentrations of the liver and lung, and in hematocrit value.Conclusion: C. purpurascens leaf extract contains antisalmonellalprinciple(s) and at high doses, may have a depressant or sedativeeffect on the central nervous system and analgesic activity.Also, it may be anorexiant, hepatotoxic, and nephrotoxic.

The effects of various processing methods on the proximate composition and dieting of Amaranthus hybridus and Amaranthus cruentus from West Cameroon were investigated in this study. Both amaranths leaves were subjected to same treatments (sun-dried and unsliced, sliced and cooked), milled, and analysed for their mineral and proximate composition. Thirty-Six Wistar albino rats of 21 to 24 days old were distributed in six groups and fed for 14 days with 10% protein based diets named D0 (protein-free diet), DI (egg white as reference protein), DII (sun-dried and unsliced A. hybridus), DIII (cooked and sliced A. hybridus), DIV (sun-dried and unsliced A. cruentus), and DV (cooked and sliced A. cruentus). The protein bioavailability and haematological and biochemical parameters were assessed in rats. The results showed that K, P, Mg, Zn, and Fe had the higher content in both samples regardless of processing method. The sun-dried and unsliced A. cruentus contained the highest value of crude protein 32.22 g/100 g DM (dry matter) while the highest crude lipid, 3.80 and 2.58%, was observed, respectively, in sun-dried and unsliced A. hybridus and cooked and sliced A. cruentus. Cooked and sliced A. hybridus and A. cruentus contained high crude fiber of 14 and 12.18%, respectively. Rats fed with diet DIII revealed the best protein bioavailability and haematological parameters whereas 100% mortality rate was recorded with group fed with diet DIV. From this study, it is evident that cooked and sliced A. hybridus and A. cruentus could play a role in weight reduction regimes.

Nefang is a polyherbal product composed of Mangifera indica (bark and leaf), Psidium guajava, Carica papaya, Cymbopogon citratus, Citrus sinensis, and Ocimum gratissimum (leaves), used for the treatment of malaria. Compounds with antioxidant activity are believed to modulate plasmodial infection. Antioxidant activity of the constituent aqueous plants extracts, in vitro, was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH), total phenolic content (TPC), and ferric reducing antioxidant power (FRAP) methods and, in vivo, Nefang (100 and 500 mg kg−1) activity was evaluated in carbon tetrachloride-induced oxidative stressed Wistar rats. Superoxide dismutase, catalase activities, and lipid peroxidation by the malondialdehyde and total proteins assays were carried out. P. guajava, M. indica leaf, and bark extracts had the highest antioxidant properties in all three assays, with no statistically significant difference. Rats treated with the carbon tetrachloride had a statistically significant decrease in levels of triglycerides, superoxide dismutase, and catalase (P