Cameroonian Medicinal Plants: Pharmacology and Derived Natural Products

Many developing countries including Cameroon have mortality patterns that reflect high levels of infectious diseases and the risk of death during pregnancy and childbirth, in addition to cancers, cardiovascular diseases and chronic respiratory diseases that account for most deaths in the developed world. Several medicinal plants are used traditionally for their treatment. In this review, plants used in Cameroonian traditional medicine with evidence for the activities of their crude extracts and/or derived products have been discussed. A considerable number of plant extracts and isolated compounds possess significant antimicrobial, anti-parasitic including antimalarial, anti-proliferative, anti-inflammatory, anti-diabetes, and antioxidant effects. Most of the biologically active compounds belong to terpenoids, phenolics, and alkaloids. Terpenoids from Cameroonian plants showed best activities as anti-parasitic, but rather poor antimicrobial effects. The best antimicrobial, anti-proliferative, and antioxidant compounds were phenolics. In conclusion, many medicinal plants traditionally used in Cameroon to treat various ailments displayed good activities in vitro. This explains the endeavor of Cameroonian research institutes in drug discovery from indigenous medicinal plants. However, much work is still to be done to standardize methodologies and to study the mechanisms of action of isolated natural products

Review of the Chemistry and Pharmacology of 7-Methyljugulone

Background: Naphthoquinone is a class of phenolic compounds derived from naphthalene. 7-Methyljuglone (7-MJ) is a naphthoquinone also known as ramentaceone or 6-Methyl-8-hydroxy-1,4-naphthoquinone or 5-Hydroxy-7-methyl-1,4-naphthoquinone or 7-Methyl-5-hydroxy-1,4-naphthoquinone or 5-Hydroxy-7-methyl-,1,4-naphtoquinone or 7-Methyl-5-hydroxynaphthalene-1,4-dione. This compound is a biologically active naphtoquinone, with a molecular weight of 188 g/mol mostly isolated in the genus Diospyros and Euclea. Objectives: This review was aimed at providing available chemically and pharmacological data on 7-MJ. Methods: The chemical and pharmacological data were retrieved from the well-known scientific websites such as Pubmed, Google Scholar, Reaxys, Scirus, Scopus, Sciencedirect, Web-of-knowledge and Scifinder. Results: 7-MJ was reported to have a variety of pharmacological activities such as antibacterial, antifungal, anticancer, antitubercular, anti-inflammatory and antiviral activities. The hemi-synthesis of the compound have been described. Conclusions: The present review pooled out together the knowledge on 7-MJ, and can serve as the start point for future research and valorization accomplishments.Keywords: 7-methyljugulone; biosynthesis; in vitro synthesis; pharmacologyAfrican Health sciences Vol 14 No. 1 March 201

Urinary tract infections, bacterial resistance and immunological status: a cross sectional study in pregnant and non-pregnant women at Mbouda Ad-Lucem Hospital

Background: Urinary tract infections (UTI) are frequently encountered medical complications of pregnancy.Objective: This study was aimed at analyzing the bacterial resistance in urogenital tract as well as the immunological profile amongst pregnant and non-pregnant women at Mbouda Ad-Lucem Hospital, Western Region of Cameroon.Methods: A cross-sectional study was carried out from December 2015 to May 2016 at Mbouda Ad-Lucem hospital on 104 pregnant women and 24 non-pregnant women. The midstream urine from participants was analysed for the presence, isolation and identification of the uro-pathogens, using selective and specific bacterial culture media. An antibiotic susceptibility tests was carried out using disk diffusion method. Blood samples were collected for C-reactive protein (CRP) dosage, CD4 and CD8 lymphocytes count.Results: Out of 128 participants in this study, a high prevalence of uro-pathogens and resistance strains was observed. The most prevalent urinary tract pathogens were Staphylococcus sp. with 45% and 38.89% respectively in pregnant and non-pregnant women. Staphylococcus sp. showed resistance to Amoxicillin (AMO; 55.56%) and Chloramphenicol (CHL; 100%) respectively in pregnant and non-pregnant women. Pregnant women had a significantly high average of granulocytes (p=0.009), monocytes (P=0.001), high ratio of CD4/CD8 (p< 0.0001) and significantly low CD8 lymphocytes (p< 0.0001) average compared to non-pregnant women.Conclusion: This study outlines high prevalence of Staphylococcus sp as the main urinary tract infectious pathogen in women at Mbouda Ad-Lucem hospital. It prevalence was accompanied with resistance to the routine antibiotics treatment, and a pro- nounced lymphocytosis and monocytosis.Keywords: Antibiotic resistance; bacterial profile; immunological status; Mbouda; multidrug-resistance; pregnancy

Potential of Central, Eastern and Western Africa Medicinal Plants for Cancer Therapy: Spotlight on Resistant Cells and Molecular Targets

Cancer remains a major health hurdle worldwide and has moved from the third leading cause of death in the year 1990 to second place after cardiovascular disease since 2013. Chemotherapy is one of the most widely used treatment modes; however, its efficiency is limited due to the resistance of cancer cells to cytotoxic agents. The present overview deals with the potential of the flora of Central, Eastern and Western African (CEWA) regions as resource for anticancer drug discovery. It also reviews the molecular targets of phytochemicals of these plants such as ABC transporters, namely P-glycoprotein (P-gp), multi drug-resistance-related proteins (MRPs), breast cancer resistance protein (BCRP, ABCG2) as well as the epidermal growth factor receptor (EGFR/ErbB-1/HER1), human tumor suppressor protein p53, caspases, mitochondria, angiogenesis, and components of MAP kinase signaling pathways. Plants with the ability to preferentially kills resistant cancer cells were also reported. Data compiled in the present document were retrieved from scientific websites such as PubMed, Scopus, Sciencedirect, Web-of-Science, and Scholar Google. In summary, plant extracts from CEWA and isolated compounds thereof exert cytotoxic effects by several modes of action including caspases activation, alteration of mitochondrial membrane potential (MMP), induction of reactive oxygen species (ROS) in cancer cells and inhibition of angiogenesis. Ten strongest cytotoxic plants from CEWA recorded following in vitro screening assays are: Beilschmiedia acuta Kosterm, Echinops giganteus var. lelyi (C. D. Adams) A. Rich., Erythrina sigmoidea Hua (Fabaceae), Imperata cylindrical Beauv. var. koenigii Durand et Schinz, Nauclea pobeguinii (Pobég. ex Pellegr.) Merr. ex E.M.A., Piper capense L.f., Polyscias fulva (Hiern) Harms., Uapaca togoensis Pax., Vepris soyauxii Engl. and Xylopia aethiopica (Dunal) A. Rich. Prominent antiproliferative compounds include: isoquinoline alkaloid isotetrandrine (51), two benzophenones: guttiferone E (26) and isoxanthochymol (30), the isoflavonoid 6α-hydroxyphaseollidin (9), the naphthyl butenone guieranone A (25), two naphthoquinones: 2-acetylfuro-1,4-naphthoquinone (4) and plumbagin (37) and xanthone V1 (46). However, only few research activities in the African continent focus on cytotoxic drug discovery from botanicals. The present review is expected to stimulate further scientific efforts to better valorize the African flora

Antibacterial activities of methanol extracts from Alchornea cordifolia and four other Cameroonian plants against MDR phenotypes

AbstractObjectivesMultidrug-resistant (MDR) bacterial infections, especially those caused by Gram-negative phenotypes, have emerged as one of the major health concerns worldwide. In the present study, we investigated the antibacterial activity of methanol extracts from five Cameroonian medicinal plants (Alchornea cordifolia, Eremomastax speciosa, Laportea aestuans, Pennisetum purpureum and Spathodea campanulata) against 15 Gram-negative bacteria that included MDR phenotypes.MethodsThe broth microdilution method was used to determine the minimal inhibitory concentrations (MIC) and the minimal bactericidal concentrations (MBC) of all of the samples. Standard phytochemical methods were used for a preliminary phytochemical screening of the plant extracts.ResultsPhytochemical analysis showed the presence of polyphenols, tannins, triterpenes and sterols in all of the studied extracts. Other chemical classes of secondary metabolites were selectively identified. The best antibacterial activities (MICs ranges of 64–1024 μg/mL) obtained against the 15 tested bacteria were found in extracts of leaves (93.3%), bark (86.7%) and roots (80%) of A. cordifolia as well as extracts of L. aestuans (86.7%) and P. purpureum (66.7%). The lowest MIC value of 64 μg/mL was recorded for the A. cordifolia bark extract against Pseudomonas aeruginosa PA01.ConclusionsThe findings of this study provide deep insights into the possible use of the studied plants, especially A. cordifolia and L. aestuans, for the control of Gram-negative bacterial infections, especially against MDR species

Urinary tract infections, bacterial resistance and immunological status: a cross sectional study in pregnant and non-pregnant women at Mbouda Ad-Lucem Hospital

Background: Urinary tract infections (UTI) are frequently encountered medical complications of pregnancy. Objective: This study was aimed at analyzing the bacterial resistance in urogenital tract as well as the immunological profile amongst pregnant and non-pregnant women at Mbouda Ad-Lucem Hospital, Western Region of Cameroon. Methods: A cross-sectional study was carried out from December 2015 to May 2016 at Mbouda Ad-Lucem hospital on 104 pregnant women and 24 non-pregnant women. The midstream urine from participants was analysed for the presence, isolation and identification of the uro-pathogens, using selective and specific bacterial culture media. An antibiotic susceptibility tests was carried out using disk diffusion method. Blood samples were collected for C-reactive protein (CRP) dosage, CD4 and CD8 lymphocytes count. Results: Out of 128 participants in this study, a high prevalence of uro-pathogens and resistance strains was observed. The most prevalent urinary tract pathogens were Staphylococcus sp. with 45% and 38.89% respectively in pregnant and non-pregnant women. Staphylococcus sp. showed resistance to Amoxicillin (AMO; 55.56%) and Chloramphenicol (CHL; 100%) respectively in pregnant and non-pregnant women. Pregnant women had a significantly high average of granulocytes (p=0.009), monocytes (P=0.001), high ratio of CD4/CD8 (p< 0.0001) and significantly low CD8 lymphocytes (p< 0.0001) average compared to non-pregnant women. Conclusion: This study outlines high prevalence of Staphylococcus sp as the main urinary tract infectious pathogen in women at Mbouda Ad-Lucem hospital. It prevalence was accompanied with resistance to the routine antibiotics treatment, and a pronounced lymphocytosis and monocytosis. DOI: https://dx.doi.org/10.4314/ahs.v19i1.26 Cite as: Ndamason LM, Marbou WJT, Kuete V. Urinary tract infections, bacterial resistance and immunological status: a cross sectional study in pregnant and non-pregnant women at Mbouda Ad-Lucem Hospital. Afri Health Sci. 2019;19(1). 1525-1535. https://dx.doi.org/10.4314/ ahs.v19i1.2

Cytotoxicity and Modes of Action of the Methanol Extracts of Six Cameroonian Medicinal Plants against Multidrug-Resistant Tumor Cells

Introduction. The present study aims at evaluating the cytotoxicity of twelve parts from six Cameroonian medicinal plants on sensitive and drug-resistant cancer cell lines. We also studied the mode of action of the most active plants, Gladiolus quartinianus, Vepris soyauxii, and Anonidium mannii. Methods. The cytotoxicity of the extracts was determined using a resazurin assay. Flow cytometry was used for cell-cycle analysis and detection of apoptosis, analysis of mitochondrial membrane potential (MMP), and measurement of reactive oxygen species (ROS). Results. At 40 g/mL, three extracts showed a growth of CCRF-CEM leukemia cells by less than 50%. This includes the extracts from G. quartinianus (GQW; 25.69%), Vepris soyauxii leaves (VSL; 29.82%), and Anonidium mannii leaves (AML; 31.58%). The lowest IC 50 values below 30 g/mL were obtained with GQW, AML and VSL against 7/9, 8/9, and 9/9 tested cancer cell lines, respectively. The lowest IC 50 values for each plant were 4.09 g/mL, and 9.14 g/mL (against U87MG.ΔEGFR cells), respectively, for VSL and AML and 10.57 g/mL (against CCRF-CEM cells) for GQW. GQW induced cell cycle arrest between G0/G1 and S phases, whilst VSL and AML induced arrest in G0/G1. All three extracts induced apoptosis in CCRF-CEM cells by loss of MMP, whilst AML also enhanced production of ROS. Conclusion. The three active plants may be a source for the development of new anticancer drugs

Cytotoxicity of Elaoephorbia drupifera and other Cameroonian medicinal plants against drug sensitive and multidrug resistant cancer cells

BACKGROUND: Multidrug resistance (MDR) is a major hurdle for cancer treatment worldwide and accounts for chemotherapy failure in over 90% of patients with metastatic cancer. Evidence of the cytotoxicity of Cameroonian plants against cancer cell lines including MDR phenotypes is been intensively and progressively provided. The present work was therefore designed to evaluate the cytotoxicity of the methanol extracts of twenty-two Cameroonian medicinal plants against sensitive and MDR cancer cell lines. METHODS: The methanol maceration was used to obtain the crude plant extracts whilst the cytotoxicity of the studied extracts was determined using a resazurin reduction assay. RESULTS: A preliminary assay on leukemia CCRF-CEM cells at 40 μg/mL shows that six of the twenty plant extract were able to enhance less than 50% of the growth proliferation of CCRF-CEM cells. These include Crinum zeylanicum (32.22%), Entada abyssinica (34.67%), Elaoephorbia drupifera (35.05%), Dioscorea bulbifera (45.88%), Eremomastax speciosa (46.07%) and Polistigma thonningii (45.11%). Among these six plants, E. drupifera showed the best activity with IC(50) values below or around 30 μg/mL against the nine tested cancer cell lines. The lowest IC(50) value of 8.40 μg/mL was recorded with the extract of E. drupifera against MDA-MB231 breast cancer cell line. The IC(50) values below 10 μg/mL were recorded with the extracts of E. drupifera against MDA-MB231 breast cancer cells, C. zeylanicum against HCT116 p53(+)/(+) and HCT116p53(-)/(-) colon cancer cells and E. abyssinica against HCT116 p53(+)/(+) cells. CONCLUSION: The results of the present study provide evidence of the cytotoxic potential of some Cameroonian medicinal plants and a baseline information for the potential use of Elaoephorbia drupifera in the treatment of sensitive and drug-resistant cancer cell lines