The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
J N Eloff - One of the best experts on this subject based on the ideXlab platform.
-
isolation of antioxidant constituents from Combretum apiculatum subsp apiculatum
South African Journal of Botany, 2012Co-Authors: M A Aderogba, L J Mcgaw, D T Kgatle, J N EloffAbstract:Abstract Species of the family Combretaceae are used extensively in traditional medicine against inflammation and infections, and although antibacterial activity has been reported in non-polar extracts, further rationale for the widespread use of the Combretaceae is expected to exist. Methanol extracts of leaves of ten different Combretum species were evaluated for antioxidant activity by spraying TLC chromatograms of each leaf extract with 2,2-diphenyl-1-picrylhydrazyl (DPPH). Compounds with antioxidant activity were detected by bleaching of the purple DPPH colour. Leaf extracts of Combretum apiculatum subsp. apiculatum had the most antioxidant compounds. This species was consequently selected for phytochemical investigation. A DPPH assay-directed fractionation of the leaf extracts of C. apiculatum led to the isolation of four antioxidant compounds from the ethyl acetate and butanol soluble fractions. The structures of the compounds were determined by spectroscopic analyses (1H-NMR, 13C-NMR and MS) and identified as: cardamonin (1), pinocembrin (2), quercetrin (3) and kaempferol (4). In a quantitative antioxidant assay, the more polar fractions (ethyl acetate and butanol) obtained by solvent–solvent fractionation had the highest antioxidant activity among the solvent fractions obtained from C. apiculatum, with EC50 values of 3.91 ± 0.02 and 2.44 ± 0.02 μg/ml respectively. Of the four isolated compounds, quercetrin (4) and kaempferol (3) had the strongest antioxidant activity, with EC50 values of 11.81 ± 85 and 47.36 ± 0.03 μM respectively. Cardamonin (1) and pinocembrin (2) did not demonstrate strong activity. L-ascorbic acid was used as standard antioxidant agent (EC50 = 13.37 ± 0.20 μM or 2.35 μg/ml). The cytotoxicity of cardamonin and pinocembrin was evaluated on Vero kidney cells using the MTT (3-(4,5-dimethylthiazol)-2,5-diphenyl tetrazolium bromide) assay with berberine as positive control. At concentrations higher than 50 μg/ml of cardamonin or pinocembrin, the cells were not viable. Cardamonin was more toxic (LC50 = 1.97 μg/ml) than pinocembrin (LC50 = 29.47 μg/ml) and even the positive control, berberine (LC50 = 12.35 μg/ml).
-
in vivo antifungal effect of Combretum and terminalia species extracts on cutaneous wound healing in immunosuppressed rats
Pharmaceutical Biology, 2010Co-Authors: P Masoko, J A Picard, R L Howard, L J Mampuru, J N EloffAbstract:Acetone leaf extracts of Combretaceae species Combretum imberbe Wawra, Combretum nelsonii Duemmer, Combretum albopunctatum Suesseng, and Terminalia sericea Burch ex DC and a mixture of asiatic acid and arjunolic acid isolated from C. nelsonii were tested for antifungal activity against Candida albicans, Cryptococcus neoformans, Microsporum canis, and Sporothrix schenckii on wounds of immunocompromised Wistar rats. The therapeutic agents were selected based on low MIC values ranging 0.02–2.5 mg/mL and low toxicity (LC50) ranging 75.7–168.6 μg/mL. Seven circular, full-thickness wounds were made on the back skin of 24 Wistar rats, under general anesthetic and using an aseptic technique. Rats were infected with different fungal pathogens in groups of six. The treatments were administered topically using 20% concentrations of each extract in aqueous cream. Amphotericin B was used as positive control. Erythema, exudate, crust formation, swelling, and ulceration were used to determine the wound healing process. ...
-
screening of twenty four south african Combretum and six terminalia species combretaceae for antioxidant activities
African Journal of Traditional Complementary and Alternative Medicines, 2008Co-Authors: P Masoko, J N EloffAbstract:The dried leaves of Combretum and Terminalia species (Combretaceae) were extracted with acetone, hexane, dichloromethane and methanol. Thin layer chromatography (TLC) plates were developed under saturated conditions and sprayed with 0.2% 2,2-diphenyl-1-picryl hydrazyl (DPPH) in methanol for antioxidant screening. Visualization of separated bands exhibiting antioxidant activities enabled the localization and the subsequent identification of the potential active compounds. The acetone and methanol extracts displayed the presence of antioxidant activity after spraying the chromatogram with DPPH. Hexane and dichloromethane extracts did not have any antioxidant activity. C. hereroense had the highest number of active compounds, followed by C. collinum ssp. taborense, which were 16 and 10, respectively. Acetone extracts of all tested Combretum species had 53 active bands and methanol had 55. All Terminalia species extracted with acetone and methanol had antioxidant activity. T. gazensis and T. mollis methanol extracts had 11 and 14 active compounds respectively in one of the solvent systems used. The qualitative DPPH assay on TLC was successfully used in this study to systematically assess the total antioxidant activity of the Combretum and Terminalia species extracts.
-
antimicrobial and anti inflammatory activity of four known and one new triterpenoid from Combretum imberbe combretaceae
Journal of Ethnopharmacology, 2007Co-Authors: Jeremiah E Angeh, Xueshi Huang, Isabel Sattler, G E Swan, Hansmartin Dahse, A Hartl, J N EloffAbstract:Combretum imberbe is used widely in Africa inter alia for treating bacterial infections. In addition to four known triterpenoids, 1alpha,3beta-dihydroxy-12-oleanen-29-oic (1), 1-hydroxy-12-olean-30-oic acid (2), 3,30-dihydroxyl-12-oleanen-22-one (3), and 1,3,24-trihydroxyl-12-olean-29-oic acid (4), a new pentacyclic triterpenoid (1alpha,23-dihydroxy-12-oleanen-29-oic acid-3beta-O-2,4-di-acetyl-L-rhamnopyranoside) 5 has been isolated through a bioassay-guided procedure from the leaves of Combretum imberbe. The structures of the compounds were elucidated on the basis of 1D and 2D NMR experiments, as well as mass spectrometric data. All compounds isolated had moderate (62 microg/ml) to strong (16 microg/ml) antibacterial activity (MIC values) against Staphylococcus aureus and Escherichia coli, with 1 and 5 being most active. Compounds 1 and 5 also showed very strong inhibition of 3alpha-hydroxysteroid dehydrogenase with an IC(50) of 0.3 microg/ml. Compound 5 indicated a moderate anti-proliferative (GI(50)=16.5 and 13.2 microg/ml) and cytotoxic activity (CC(50)=17.6 micro/ml) against K-562, L-929 and HeLa cell lines, respectively. The results of this study give credence to the ethnomedicinal use of Combretum imberbe and expand our knowledge on the biological activity of its metabolites.
-
bioautography indicates the multiplicity of antifungal compounds from twenty four southern african Combretum species combretaceae
African Journal of Biotechnology, 2006Co-Authors: P Masoko, J N EloffAbstract:Dried ground leaves of 24 Combretum spp were extracted with hexane, dichloromethane, acetone and methanol and analysed by bioautography to determine the number of antifungal compounds against five animal fungal pathogens (Candida albicans, Cryptococcus neoformans, Aspergillus fumigatus, Microsporum canis and Sporothrix schenckii). There was some similarity in the chemical composition of the non-polar components of extracts using extractants of varying polarity. Acetone extracted the most antifungal compounds from Combretum spp. Combretum spp. in the section Hypocrateropsis, C. celastroides ssp. celastroides and C. clelastroides ssp. orientale had 62 different antifungal zones of inhibition compared to the 7 to 8 of C. microphyllum and C. paniculatum in the Connivetaia section. C. collinum subspecies were not active against all the tested pathogens. C. neoformans was the most sensitive organism against all Combretum species, with 367 zones of inhibition using different TLC solvent systems and extracts. A. fumigatus was the most resistant (192 zones of inhibition). The antifungal activity and number of active antifungal compounds were high enough to consider the use of extracts for clinical application and to isolate antifungal compounds from the extracts. Based on the Rf values of the antifungal compounds determined using solvents of varying polarity, activity is not only be attributable to tannins found in Combretum extracts as was previously postulated.
Stanley Mukanganyama - One of the best experts on this subject based on the ideXlab platform.
-
the effects of combining cancer drugs with compounds isolated from Combretum zeyheri sond and Combretum platypetalum welw ex m a lawson combretaceae on the viability of jurkat t cells and hl 60 cells
BioMed Research International, 2021Co-Authors: Morris Wende, Simbarashe Sithole, Godloves Fru Chi, Marc Y Stevens, Stanley MukanganyamaAbstract:Combretum zeyheri and Combretum platypetalum have been shown to have anticancer, antibacterial, antituberculosis, and antifungal effects in both in vivo and in vitro studies. This study sought to evaluate the antiproliferative effects of compounds isolated from C. zeyheri and C. platypetalum on Jurkat T and HL-60 cancer cell lines in combination with doxorubicin and/or chlorambucil. At their GI50 concentrations, the isolated compounds were combined with the corresponding GI50 of chlorambucil and doxorubicin. The cytotoxic effects of the combined compounds were determined on BALB/c mouse peritoneal cells. All the 4 isolated compounds had significant cytotoxic effects on Jurkat T cells. Compounds CP 404 (1), CP 409 (2), CZ 453 (3), and CZ 455 (4) had GI50s on Jurkat T cells of 3.98, 19.33, 6.82, and 20.28 μg/ml, respectively. CP 404 (1), CP 409 (2), CZ 453 (3), and CZ 455 (4) showed GI50s of 14.18, 28.69, 29.87, and 16.46 μg/ml on HL-60 cancer cell lines, respectively. The most potent combination against Jurkat T cells was found to be CP 404 (1) and chlorambucil. This combination showed no cytotoxic effects when tested on BALB/c mouse peritoneal cells. It was concluded that the compounds extracted from C. zeyheri and C. platypetalum inhibit the growth of Jurkat T cells in vitro. The combination of the compounds with anticancer drugs enhanced their anticancer effects. The combination of CP 404 (1) and chlorambucil was found not to be toxic to normal mammalian cells. Therefore, CP 404 (1), 3-O-β-L-rrhamnopyranosyl-5,7,3 4 ,5 - pentahydroxyflavone, has the potential to be a source of lead compounds that can be developed for anticancer therapy. Further structure-activity relationship studies on this compound are warranted.
-
alkaloid extracts from Combretum zeyheri inhibit the growth of mycobacterium smegmatis
BMC Complementary and Alternative Medicine, 2017Co-Authors: Tafadzwa Nyambuya, Ruvimbo Mautsa, Stanley MukanganyamaAbstract:Current tuberculosis regimens have failed to combat the issue of drug resistance and ethno medicines may represent a possible source of antimycobacterial agents. Combretum species are well known in African traditional medicines and used for various ailments including pneumonia, venereal diseases like syphilis, mental problems, relief of sore throats and colds, fever, and chest coughs associated with tuberculosis. Alkaloids function as either hydrogen-acceptor or hydrogen-donor in hydrogen bonding critical for the interaction between targets thus, potentiating effects of curative agents on diseases. Alkaloid extracts from leaves of Combretum zeyheri, Combretum platypetalum, Combretum molle and Combretum apiculatum, were assessed for antimycobacterial activity to establish rationale for their use in traditional medicines for various ailments including pneumonia, relief of sore throats and colds, fever, and chest coughs associated with tuberculosis. Alkaloids were extracted from the leaves of Combretum zeyheri, Combretum platypetalum, Combretum molle and Combretum apiculatum. The broth microdilution method was used for the screening of growth inhibitory activity. The standard drug rifampicin was used as the positive control. Alkaloid extracts from the most potent plant species, Combretum zeyheri were further investigated for time-kill dependency effects on drug transport in Mycobacterium smegmatis. Using the broth microdilution susceptibility method, C. zeyheri alkaloid extract, was found to have the most antimycobacterial effects with an MIC value of 125 μg/ml whilst MICs for C. molle and C. platypetalum were above 1000 μg/ml. An MBC value of 250 μg/ml was observed with alkaloid extracts from Combretum zeyheri whilst the remaining three Combretum species showed no bactericidal activity. It was also shown that C. zeyheri had potential efflux pump inhibitory activity. Determination of the time-kill kinetics of extracts from C. zeyheri showed not only a concentration-dependent activity but time-dependent bactericidal effect as well. Alkaloid extracts from the leaves of C. zeyheri have potential as a source of lead compounds that may be developed further into antimycobacterial compounds. The mechanism of action of may be due to inhibition of transport across the cell membrane. Further work needs to be done to isolate the active components in these extracts.
-
in vivo and in vitro inhibition of rat liver glutathione transferases activity by extracts from Combretum zeyheri combretaceae and parinari curatellifolia chrysobalanaceae
BMC Complementary and Alternative Medicine, 2016Co-Authors: David Gweshelo, Rudo Muswe, Stanley MukanganyamaAbstract:Parinari curatellifolia and Combretum zeyheri are medicinal plants used in Zimbabwe and other Southern African countries for stomach ailments, fever, body aches, wound healing, cancer and tuberculosis. Glutathione transferases (GSTs) are mammalian enzymes that play a significant role in the detoxification and metabolism of many xenobiotic and endogenous compounds and as such can interact with many exogenous compounds including herbal medicines. The effects of Parinari curatellifolia and Combretum zeyheri leaf extracts on glutathione transferases of male Sprague–Dawley rats were investigated in vivo and in vitro after oral administration of either leaf ethanol or water extracts of each plant. For Parinari curatellifolia, 18 male Sprague-Dawley rats were administered with 0, 500 and 1000 mg/kg body weight of the leaf extracts in corn oil or saline. Animals were sacrificed after 96 h and the kidney and liver samples were removed and used to prepare the cytosolic fractions. GST activity was determined using 1-chloro-2, 4-dinitrobezene. For Combretum zeyheri, twenty four male Sprague–Dawley rats were randomly divided into two groups. These two groups were further divided into three groups of four animals each. They were given either the aqueous or ethanol extract at doses of C. zeyheri at 0, 50 mg/kg body weight and 200 mg/kg body weight. The extracts were administered orally by oral gavage for four consecutive days and the rats were sacrificed by cervical dislocation on the fifth day. In animals administered with C. zeyheri, GST activity was significantly increased by the 200 mg/kg aqueous extract in the kidneys and livers in vivo whilst the ethanolic extract at 200 mg/kg decreased enzyme activity significantly both organs. Both the ethanol and aqueous extracts inhibited GST activity in vitro with the ethanol extract being more potent inhibitor than ethacrynic acid, a standard GST inhibitor. The increased GST activity in vivo and versus inhibition in vitro suggests that metabolites may be responsible for the effects observed in vivo. For P. curatellifolia, a dose-dependent decrease in GST activity was observed in vivo for the animals given the aqueous extract but no changes were observed with the ethanol extract. There was a concentration-dependent inhibition of cytosolic GSTs when P. curatellifolia leaf extracts in vitro. The ethanol extract of P. curatellifolia exhibited GST-inhibitory activity in the liver with an IC50 value of 12 μg/mL and for ethacrynic acid, the IC50 was found to be 10 μg/mL. This showed that this extract was a potent inhibitor of GSTs in vitro. C. zeyheri had an inductive effect on GST activity when administered in aqueous solution but inhibited GST in vitro whilst P. curatellifolia inhibited GST activity in vivo. Induction of GSTs would be cytoprotective against the toxic effects electrophilic chemicals. Since GSTs are responsible for the synthesis of prostaglandins, the inhibition of GST activity of by these two plants in vivo maybe one of the reasons that makes the plants important for use in the treatment pain and fever in ethnopharmacology.
Victor Kuete - One of the best experts on this subject based on the ideXlab platform.
-
antibacterial and antibiotic resistance modifying activity of the extracts from allanblackia gabonensis Combretum molle and gladiolus quartinianus against gram negative bacteria including multi drug resistant phenotypes
BMC Complementary and Alternative Medicine, 2015Co-Authors: Aime G Fankam, J R Kuiate, Victor KueteAbstract:Background Bacterial resistance to antibiotics is becoming a serious problem worldwide. The discovery of new and effective antimicrobials and/or resistance modulators is necessary to tackle the spread of resistance or to reverse the multi-drug resistance. We investigated the antibacterial and antibiotic-resistance modifying activities of the methanol extracts from Allanblackia gabonensis, Gladiolus quartinianus and Combretum molle against 29 Gram-negative bacteria including multi-drug resistant (MDR) phenotypes.
-
antibacterial and antibiotic resistance modifying activity of the extracts from allanblackia gabonensis Combretum molle and gladiolus quartinianus against gram negative bacteria including multi drug resistant phenotypes
BMC Complementary and Alternative Medicine, 2015Co-Authors: Aime G Fankam, J R Kuiate, Victor KueteAbstract:Bacterial resistance to antibiotics is becoming a serious problem worldwide. The discovery of new and effective antimicrobials and/or resistance modulators is necessary to tackle the spread of resistance or to reverse the multi-drug resistance. We investigated the antibacterial and antibiotic-resistance modifying activities of the methanol extracts from Allanblackia gabonensis, Gladiolus quartinianus and Combretum molle against 29 Gram-negative bacteria including multi-drug resistant (MDR) phenotypes. The broth microdilution method was used to determine the minimal inhibitory concentrations (MIC) and minimal bactericidal concentrations (MBC) of the samples meanwhile the standard phytochemical methods were used for the preliminary phytochemical screening of the plant extracts. Phytochemical analysis showed the presence of alkaloids, flavonoids, phenols and tannins in all studied extracts. Other chemical classes of secondary metabolites were selectively presents. Extracts from A. gabonensis and C. molle displayed a broad spectrum of activity with MICs varying from 16 to 1024 μg/mL against about 72.41 % of the tested bacteria. The extract from the fruits of A. gabonensis had the best activity, with MIC values below 100 μg/mL on 37.9 % of tested bacteria. Percentages of antibiotic-modulating effects ranging from 67 to 100 % were observed against tested MDR bacteria when combining the leaves extract from C. molle (at MIC/2 and MIC/4) with chloramphenicol, kanamycin, streptomycin and tetracycline. The overall results of the present study provide information for the possible use of the studied plant, especially Allanblackia gabonensis and Combretum molle in the control of Gram-negative bacterial infections including MDR species as antibacterials as well as resistance modulators.
Valdir Alves Facundo - One of the best experts on this subject based on the ideXlab platform.
-
a lupane triterpene isolated from Combretum leprosum mart fruit extracts that interferes with the intracellular development of leishmania l amazonensis in vitro
BMC Complementary and Alternative Medicine, 2015Co-Authors: Carolina Bioni Garcia Teles, Valdir Alves Facundo, Rodrigo G. Stábeli, Alexandre De Almeida E Silva, Walter Filgueira De Azevedo, Maria Cristina M. Motta, Leandro S Moreiradill, Luiz Pereira Da Silva, Izaltina SilvajardimAbstract:Background 3beta,6beta,16beta-trihydroxylup-20(29)-ene is a lupane triterpene isolated from Combretum leprosum fruit. The lupane group has been extensively used in studies on anticancer effects; however, its possible activity against protozoa parasites is yet poorly known. The high toxicity of the compounds currently used in leishmaniasis chemotherapy stimulates the investigation of new molecules and drug targets for antileishmanial therapy.
-
counteraction of bothrops snake venoms by Combretum leprosum root extract and arjunolic acid
Journal of Ethnopharmacology, 2014Co-Authors: Fabricio F A Fernandes, Valdir Alves Facundo, Marcelo A Tomaz, Camila Z Elkik, Marcos Monteiromachado, Marcelo A Strauch, Bruno L Cons, Matheus S Tavareshenriques, Adelia Cristina Oliveira Cintra, Paulo A MeloAbstract:Abstract Ethnopharmacological relevance Serotherapy against snakebite is often unavailable in some regions over Brazil, where people make use of plants from folk medicine to deal with ophidic accidents. About 10% of Combretum species have some ethnopharmacological use, including treatment of snakebites. Materials and methods We evaluated the ability of the extract of Combretum leprosum and its component arjunolic acid to reduce some in vivo and in vitro effects of Bothrops jararacussu and Bothrops jararaca venoms. The protocols investigated include phospholipase, proteolytic, collagenase, hyaluronidase, procoagulant, hemorrhagic, edematogenic, myotoxic and lethal activities induced by these venoms in Swiss mice. Results Oral pre-treatment with arjunolic acid reduced the Bothrops jararacussu lethality in up to 75%, while preincubation prevented the death of all the animals. Hemoconcentration effect of Bothrops jararacussu venom was confirmed two hours after i.p. injection, while preincubation with arjunolic acid preserved the hematocrit levels. Both Combretum leprosum extract and arjunolic acid abolished the myotoxic action of Bothrops jararacussu venom. Preincubation of Bothrops jararacussu venom with the extract or arjunolic acid prevented the increase of plasma creatine kinase activity in mice. The hemorrhagic activity of Bothrops jararaca crude venom was reduced down to about 90% and completely inhibited by preincubation with 10 mg/kg or 100 mg/kg Combretum leprosum extract, respectively, while the preincubation and the pretreatment with 30 mg/kg of arjunolic acid reduced the venom hemorrhagic activity down to about 12% and 58%, respectively. The preincubation of the venom with both extract and 30 mg/kg arjunolic acid significantly reduced the bleeding amount induced by Bothrops jararacussu venom. The extract of Combretum leprosum decreased the edema formation induced by Bothrops jararacussu venom both in preincubation and pretreatment, but not in posttreatment. Similarly, arjunolic acid preincubated with the venom abolished edema formation, while pre- and posttreatment have been partially effective. Some enzymatic activities of Bothrops jararacussu and Bothrops jararaca venoms, i.e. phospholipase A 2 , collagenase, proteolytic and hyaluronidase activities, were to some extent inhibited by the extract and arjunolic acid in a concentration-dependent manner. Conclusions Altogether, our results show that Combretum leprosum extract can inhibit different activities of two important Brazilian snake venoms, giving support for its popular use in folk medicine in the management of venomous snakebites.
-
Combretum leprosum mart combretaceae potential as an antiproliferative and anti inflammatory agent
Journal of Ethnopharmacology, 2013Co-Authors: Cintia Delai Da Silva Horinouchi, Valdir Alves Facundo, Daniel Augusto Gasparin Bueno Mendes, Bruna Da Silva Soley, Evelise Fernandes Pietrovski, Adair R S Santos, Daniela Almeida Cabrini, Michel Fleith OtukiAbstract:Abstract Ethnopharmacological relevance Combretum leprosum is a species that is popularly used in Brazil as a healing agent to treat skin problems and lesions. In this study we investigated the possible potential of this extract to treat inflammatory and hyperproliferative skin conditions. Materials and methods Classical models of skin inflammation such as TPA- and croton oil-induced mouse ear oedema were applied in order to verify the potential topical anti-inflammatory activity of the ethanolic extract from flowers of Combretum leprosum . Results Topical application of ethanolic extract promoted a dose-dependent inhibition of phorbol ester-induced ear oedema, reduced myeloperoxidase activity and IL-6 tissue levels with inhibition comparable to dexamethasone (positive control). Histological and immunohistochemical analysis revealed that ethanolic extract also suppressed cell infiltration. Ethanolic extract altered inflammatory parameters on a chronic skin inflammation model induced by repeated applications of croton oil, decreasing ear oedema, epidermal hyperproliferation and cell infiltration. In addition, immunohistochemical analysis showed that the extract decreased PCNA expression on the epidermis. Conclusion Taken together, these results suggest that the extract from flowers of Combretum leprosum could be considered as a new potential tool for the treatment of several skin inflammatory diseases since it reversed the skin inflammatory and hyperproliferative process in a very significant manner. Further investigations are needed in order to verify the cellular mechanism and safety of Combretum leprosum extract.
-
arjunolic acid in the ethanolic extract of Combretum leprosum root and its use as a potential multi functional phytomedicine and drug for neurodegenerative disorders anti inflammatory and anticholinesterasic activities
Journal of the Brazilian Chemical Society, 2005Co-Authors: Valdir Alves Facundo, Katiuscia Rios, Cileia M Medeiros, Julio Sancho Linhares Teixeira Militao, Ana L P Miranda, Rosângela De A Epifanio, Meriane P Carvalho, Aline T Andrade, Angelo C Pinto, Claudia M RezendeAbstract:Combretum leprosum Mart. & Eicher (Combretaceae) leaves and roots ethanolic extracts were investigated by HRGC-MS and showed mono- and oligosaccharides, fatty acids and triterpenes as major compounds after derivatization with BSTFA/ TMCS. Arjunolic acid (1) was quantified on dried roots ethanolic extract (65%) by external standard. Anti-inflammatory, antinociceptive and anticholinesterasic (AChE and BuChE) activities were observed for roots ethanolic extract of C. leprosum and arjunolic acid, suggesting both as promising targets for the development of innovative multi-functional medicines for Alzheimer desease treatment.
-
triterpenes and flavonoids from Combretum leprosum
Phytochemistry, 1993Co-Authors: Valdir Alves Facundo, C H S Andrade, Edilberto R Silveira, Raimundo Brazfilho, Charles D HuffordAbstract:Abstract A new triterpene 3β,6β,16β-trihydroxylup-20(29)-ene, arjunolic acid, mollic acid, 3- 0 -methylquercetin and quercetrin were isolated from the leaves and roots of Combretum leprosum . The structures of these compounds have been determined by chemical and spectrometric methods, especially extensive 1D and 2D NMR experiments, including the use of the INADEQUATE technique for the new triterpene 3β,6β,16β-trihydroxylup-20(29)-ene.
Aime G Fankam - One of the best experts on this subject based on the ideXlab platform.
-
antibacterial and antibiotic resistance modifying activity of the extracts from allanblackia gabonensis Combretum molle and gladiolus quartinianus against gram negative bacteria including multi drug resistant phenotypes
BMC Complementary and Alternative Medicine, 2015Co-Authors: Aime G Fankam, J R Kuiate, Victor KueteAbstract:Background Bacterial resistance to antibiotics is becoming a serious problem worldwide. The discovery of new and effective antimicrobials and/or resistance modulators is necessary to tackle the spread of resistance or to reverse the multi-drug resistance. We investigated the antibacterial and antibiotic-resistance modifying activities of the methanol extracts from Allanblackia gabonensis, Gladiolus quartinianus and Combretum molle against 29 Gram-negative bacteria including multi-drug resistant (MDR) phenotypes.
-
antibacterial and antibiotic resistance modifying activity of the extracts from allanblackia gabonensis Combretum molle and gladiolus quartinianus against gram negative bacteria including multi drug resistant phenotypes
BMC Complementary and Alternative Medicine, 2015Co-Authors: Aime G Fankam, J R Kuiate, Victor KueteAbstract:Bacterial resistance to antibiotics is becoming a serious problem worldwide. The discovery of new and effective antimicrobials and/or resistance modulators is necessary to tackle the spread of resistance or to reverse the multi-drug resistance. We investigated the antibacterial and antibiotic-resistance modifying activities of the methanol extracts from Allanblackia gabonensis, Gladiolus quartinianus and Combretum molle against 29 Gram-negative bacteria including multi-drug resistant (MDR) phenotypes. The broth microdilution method was used to determine the minimal inhibitory concentrations (MIC) and minimal bactericidal concentrations (MBC) of the samples meanwhile the standard phytochemical methods were used for the preliminary phytochemical screening of the plant extracts. Phytochemical analysis showed the presence of alkaloids, flavonoids, phenols and tannins in all studied extracts. Other chemical classes of secondary metabolites were selectively presents. Extracts from A. gabonensis and C. molle displayed a broad spectrum of activity with MICs varying from 16 to 1024 μg/mL against about 72.41 % of the tested bacteria. The extract from the fruits of A. gabonensis had the best activity, with MIC values below 100 μg/mL on 37.9 % of tested bacteria. Percentages of antibiotic-modulating effects ranging from 67 to 100 % were observed against tested MDR bacteria when combining the leaves extract from C. molle (at MIC/2 and MIC/4) with chloramphenicol, kanamycin, streptomycin and tetracycline. The overall results of the present study provide information for the possible use of the studied plant, especially Allanblackia gabonensis and Combretum molle in the control of Gram-negative bacterial infections including MDR species as antibacterials as well as resistance modulators.