The Chemical Composition and Antibacterial Activities of the Essential Oils from Three Aframomum Species from Cameroon, and Their Potential as Sources of (E)-(R)-Nerolidol

International audienceEssential oils obtained by hydrodistillation of seeds, pericarps, leaves and rhizomes of Aframomum dalzielii, A. letestuianum and A. pruinosum grown in Cameroon were analyzed by GC-FID and GC-MS. The seed oils of the three species were characterized by a high content of (E)-(R)-nerolidol (>88.0 %), which was fully characterized by NMR spectroscopy and chiral GC analysis. The main constituents of the pericarp and rhizome oils were monoterpene hydrocarbons, mainly beta-pinene (0.8%-22.9%) and sabinene (29.0%-42.3%), along with 1,8-cineole (4.5%-23.7%); leaf oils were characterized by sesquiterpenes, namely (E)-beta-caryophyllene (18.4%-82.4%) and caryophyllene oxide (4.5%-23.7%). The antibacterial activities of these essential oils and of nine pure compounds (sabirtene, beta-pinene, 1,8-cineole, linalool, racemic (E)-nerolidol, (E)-(R)-nerolidol, (E)-beta-caryophyllene, a-humulene and caryophyllene oxide) were assessed against Micrococcus luteus and Escherichia coli. The strongest activities were observed against E. coli. The seed essential oils and their major component, (E)-(R)-nerolidol, exhibited the lowest MIC values (0.19-0.39 mu L/mL), justifying their traditional use and their potential application as natural food preservatives

The Chemical Composition and Antibacterial Activities of the Essential Oils from Three Aframomum Species from Cameroon, and Their Potential as Sources of (E)-(R)-Nerolidol

Essential oils obtained by hydrodistillation of seeds, pericarps, leaves and rhizomes of Aframomum dalzielii, A. letestuianum and A. pruinosum grown in Cameroon were analyzed by GC-FID and GC-MS. The seed oils of the three species were characterized by a high content of (E)-(R)-nerolidol (>88.0 %), which was fully characterized by NMR spectroscopy and chiral GC analysis. The main constituents of the pericarp and rhizome oils were monoterpene hydrocarbons, mainly beta-pinene (0.8%-22.9%) and sabinene (29.0%-42.3%), along with 1,8-cineole (4.5%-23.7%); leaf oils were characterized by sesquiterpenes, namely (E)-beta-caryophyllene (18.4%-82.4%) and caryophyllene oxide (4.5%-23.7%). The antibacterial activities of these essential oils and of nine pure compounds (sabirtene, beta-pinene, 1,8-cineole, linalool, racemic (E)-nerolidol, (E)-(R)-nerolidol, (E)-beta-caryophyllene, a-humulene and caryophyllene oxide) were assessed against Micrococcus luteus and Escherichia coli. The strongest activities were observed against E. coli. The seed essential oils and their major component, (E)-(R)-nerolidol, exhibited the lowest MIC values (0.19-0.39 mu L/mL), justifying their traditional use and their potential application as natural food preservatives

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

A review of Cameroonian medicinal plants with potentials for the management of the COVID-19 pandemic

Since the outbreak in December 2019, in Wuhan (China) of COVID-19, approved drugs are still lacking and the world is seeking effective treatment. The purpose of this article is to review the medicinal plants with potential to be used as complementary therapies against COVID-19. Bibliographic information was searched in several databases (Google Scholar, PubMed, Scopus, ScienceDirect, PROTA, ResearchGate and GLOBEinMED), to retrieve relevant papers on (1) plants used to manage common symptoms of COVID-19, (2) plant secondary metabolites with confirmed inhibitory effects on COVID-19 and (3) plants exhibiting pharmacological activities of relevance for COVID-19 management. A total of 230 species was recorded as potential source of ingredients for the fight against the 2019 novel corona virus. Of these species, 30 contain confirmed antiCOVID-19 secondary metabolites, 90 are used traditionally to manage at least 3 common symptoms of COVID-19, 10 have immunostimulant activity, 52 have anti-inflamatory activity, 14 have antiviral properties and 78 species are documented as used to treat malaria. A PCA analysis showing cluster formatting among the recorded species indicates 4 groups of species and an array of possibility of using individual species or a combination of species for their complementary effects. The authors argue that Cameroonian medicinal plants can be of potential contribution to the fight against COVID-19. Further applied research is needed to provide more scientific evidence for their efficacy, to establish standard formulations and clinical studies as part of efforts to develop therapies for COVID-19

Incidence of cervical disease associated to HPV in human immunodeficiency infected women under highly active antiretroviral therapy

<p>Abstract</p> <p>Background</p> <p>Women infected with human immunodeficiency virus (HIV) may be at higher risk of developing cervical cancer than non infected women. In a pilot study, we assessed the relationships among cervical cytology abnormalities associated to Human Papillomavirus (HPV), HIV infection and Highly Active Antiretroviral Therapy (HAART) on the development of Squamous Intraepithelial lesions (SILs). Out of the 70 HIV infected women from Douala -Cameroon (Central Africa) that we included in the study, half (35) were under HAART. After obtaining information related to their lifestyle and sexual behaviour, cervicovaginal samples for Pap smears and venous blood for CD4 count were collected and further divided into two groups based upon the presence or absence of cervical cytology abnormalities i.e. those with normal cervical cytology and those with low and high Squamous Intraepithelial lesions (LSIL, HSIL).</p> <p>Results</p> <p>Assessment was done according to current antiretroviral regimens available nationwide and CD4 count. It was revealed that 44.3% of HIV-infected women had normal cytology. The overall prevalence of LSIL and HSIL associated to HPV in the studied groups was 24.3% (17/70) and 31.4% (22/70) respectively. Among the 22 HSIL-positive women, 63.6% (14/22) were not on antiretroviral therapy, while 36.4% (8/22) were under HAART. HIV infected women under HAART with positive HSIL, showed a median CD4+ T cell count of 253.7 +/- 31.7 higher than those without therapy (164.7 +/- 26.1). The incidence of HSIL related to HPV infection within the study group independently of HAART initiation was high.</p> <p>Conclusion</p> <p>These results suggest the need for extension and expansion of the current study in order to evaluate the incidence of HPV infection and cervical cancer among HIV-infected and non HIV- infected women in Cameroon.</p