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

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

Antibacterial activities of selected edible plants extracts against multidrug-resistant Gram-negative bacteria

BACKGROUND: In response to the propagation of bacteria resistant to many antibiotics also called multi-drug resistant (MDR) bacteria, the discovery of new and more efficient antibacterial agents is primordial. The present study was aimed at evaluating the antibacterial activities of seven Cameroonian dietary plants (Adansonia digitata, Aframomum alboviolaceum, Aframomum polyanthum, Anonidium. mannii, Hibiscus sabdarifa, Ocimum gratissimum and Tamarindus indica). METHODS: The phytochemical screening of the studied extracts was performed using described methods whilst the liquid broth micro dilution was used for all antimicrobial assays against 27 Gram-negative bacteria. RESULTS: The results of the phytochemical tests indicate that all tested extracts contained phenols and triterpenes, other classes of chemicals being selectively present. The studied extracts displayed various degrees of antibacterial activities. The extracts of A. digitata, H. sabdarifa, A. polyanthum, A. alboviolaceum and O. gratissimum showed the best spectra of activity, their inhibitory effects being recorded against 81.48%, 66.66%, 62.96%, 55.55%, and 55.55% of the 27 tested bacteria respectively. The extract of A. polyanthum was very active against E. aerogenes EA294 with the lowest recorded minimal inhibitory concentration (MIC) of 32 μg/ml. CONCLUSION: The results of the present work provide useful baseline information for the potential use of the studied edible plants in the fight against both sensitive and MDR phenotypes

Syzygium jambos

The present study was designed to evaluate the antibacterial activities of methanol extracts of bark and leaves of Syzygium jambos, as well as their synergistic effects with selected antibiotics against drug-resistant Gram-positive and Gram-negative bacteria. The crude extracts were subjected to qualitative phytochemical screening; broth microdilution method was used for antibacterial assays. Phytochemical studies indicate that leaves and bark extracts contained polyphenols, anthraquinones, tannins, and steroids. Extract of the leaves was active against all the 26 strains of Staphylococcus aureus and all the 21 strains of Gram-negative bacteria tested, within the minimum inhibitory concentration (MIC) range of 32–512 μg/mL. The lowest MIC value of 32 μg/mL was obtained with extract of the leaves against Staphylococcus aureus MRSA9 strain. In Gram-negative bacteria, the lowest MIC value of 64 μg/mL was also obtained against Enterobacter aerogenes EA294 and Klebsiella pneumoniae K24 strains. Against S. aureus strains, antibiotic-modulating activity of extracts at MIC/2 towards more than 70% of the tested strains was obtained when leaves and bark extracts were tested in association with chloramphenicol (CHL). This was also the case when leaves extract was combined with CHL, kanamycin (KAN), tetracycline (TET), and erythromycin (ERY) and when bark extract was combined with ciprofloxacin (CIP), TET, and ERY against Gram-negative bacteria. In conclusion, this study demonstrated that Syzygium jambos has antibacterial and antibiotic-modulating activities

Multidrug resistant bacteria are sensitive to Euphorbia prostrata and six others Cameroonian medicinal plants extracts

Abstract Background Multidrug resistant (MDR) bacteria are responsible for therapeutic failure and there is an urgent need for novels compounds efficient on them. Methods Eleven methanol extracts from seven Cameroonian medicinal plants were tested for their antibacterial activity using broth micro-dilution method against 36 MDR bacterial strains including Escherichia coli, Enterobacter aerogenes, Enterobacter cloacae, Klebsiella pneumoniae, Providencia stuartii, Pseudomonas aeruginosa and Staphylococcus aureus. Results Euphorbia prostrata extract was found active against all the 36 tested bacteria including Gram-negative phenotypes over-expressing efflux pumps such as P. aeruginosa PA124, E. aerogenes CM64 and E. coli AG102. E. prostrata had minimal inhibitory concentrations values between 128 and 256 µg/mL on 55.55% of the studied microorganisms. Other plants extract displayed selective antibacterial activity. Conclusions Results obtained in this study highlight the antibacterial potential of the tested plants and the possible use of E. prostrata to combat bacterial infections including MDR phenotypes

Antibacterial activities of the methanol extracts of Albizia adianthifolia, Alchornea laxiflora, Laportea ovalifolia and three other Cameroonian plants against multi-drug resistant Gram-negative bacteria

In the last 10 years, resistance in Gram-negative bacteria has been increasing. The present study was designed to evaluate the in vitro antibacterial activities of the methanol extracts of six Cameroonian medicinal plants Albizia adianthifolia, Alchornea laxiflora, Boerhavia diffusa, Combretum hispidum, Laportea ovalifolia and Scoparia dulcis against a panel of 15 multidrug resistant Gram-negative bacterial strains. The broth microdilution was used to determine the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of the extracts. The preliminary phytochemical screening of the extracts was conducted according to the reference qualitative phytochemical methods. Results showed that all extracts contained compounds belonging to the classes of polyphenols and triterpenes, other classes of chemicals being selectively distributed. The best antibacterial activities were recorded with bark and root extracts of A. adianthifolia as well as with L. ovalifolia extract, with MIC values ranging from 64 to 1024 μg/mL on 93.3% of the fifteen tested bacteria. The lowest MIC value of 64 μg/mL was recorded with A. laxiflora bark extract against Enterobacter aerogenes EA289. Finally, the results of this study provide evidence of the antibacterial activity of the tested plants and suggest their possible use in the control of multidrug resistant phenotypes

Antibacterial and antibiotic-potentiation activities of the methanol extract of some cameroonian spices against Gram-negative multi-drug resistant phenotypes

<p>Abstract</p> <p>Background</p> <p>The present work was designed to evaluate the antibacterial properties of the methanol extracts of eleven selected Cameroonian spices on multi-drug resistant bacteria (MDR), and their ability to potentiate the effect of some common antibiotics used in therapy.</p> <p>Results</p> <p>The extract of <it>Cinnamomum zeylanicum</it> against <it>Escherichia coli</it> ATCC 8739 and AG100 strains showed the best activities, with the lowest minimal inhibitory concentration (MIC) of 64 μg/ml. The extract of <it>Dorstenia psilurus</it> was the most active when tested in the presence of an efflux pump inhibitor, phenylalanine Arginine<it>-β-</it> Naphtylamide (PAβN), a synergistic effect being observed in 56.25 % of the tested bacteria when it was combined with Erythromycin (ERY).</p> <p>Conclusion</p> <p>The present work evidently provides information on the role of some Cameroonian spices in the fight against multi-resistant bacteria.</p