Mutagenicity, antimutagenicity and cytotoxicity evaluation of South African Podocarpus species

Ethnopharmacological relevance

Four species of Podocarpus are used in traditional medicine both in human and animal healthcare in South Africa. In vitro pharmacological screening of leaf and stem extracts of these species exhibited potent antimicrobial, anti-inflammatory, anti-tyrosinase, anthelmintic, acetylcholinesterase inhibitory and antioxidant activities.

Aim of the study

To investigate the mutagenicity, antimutagenicity and cytotoxicity effects of leaf and stem extract of South African Podocarpus species.

Material and methods

The mutagenicity and cytotoxic effects of extracts from four species of Podocarpus were tested using the Salmonella/microsome assay with and without metabolic activation, based on the plate-incorporation method and neutral red uptake (NRU) assay respectively. Five Salmonella typhimurium tester strains; TA98, TA100, TA102, TA1535 and TA1537 were used for mutagenicity testing. The relative cytotoxicity of the extracts was assessed by determining their NI₅₀ values (50% inhibition of NRU).

Results

The extracts did not show any mutagenic effects against all the tester strains with or without metabolic activation. All extracts demonstrated a strong antimutagenic effect on the mutations induced by 4NQO, decreasing its mutagenic effect in a dose-dependent manner. Strong cytotoxic effects were exhibited by petroleum ether extracts as compared to 80% ethanol extracts. When HepG2 cells were in contact with plant extracts in an increasing concentration, slopes of NRU decreased (highest-lowest %) following a concentration-dependent pattern. For 80% ethanol extracts, the most toxic extract in terms of percentage viability was leaves of Podocarpus falcatus whereby at 0.2 mg/ml, the viability of the cells was 38.9%. Stem extract of Podocarpus latifolius was the most toxic among PE extracts, giving a percentage viability of 46.4 at 0.1 mg/ml.

Conclusion

Absence of mutagenicity does not indicate lack of toxicity, as was observed from these extracts. These findings will help in assessing the safety measures to be considered in the use of these species and also the need to determine the cytotoxic potential of these species against various forms of human cancer cells.     

Antifungal activity and cytotoxicity of isolated compounds from leaves of Breonadia salicina

Ethnopharmacological relevance

Breonadia salicina is used traditionally to treat wounds, ulcers, fevers, headaches, and fungal infections. The aim of this study was to investigate the antifungal activity of the plant extract and compounds isolated there from.

Materials and Methods

Leaf extracts of Breonadia salicina were screened for antifungal activity against seven plant pathogens: Aspergillus niger, Aspergillus parasiticus, Colletotrichum gloeosporioides, Trichoderma harzianum, Penicillium expansum, Penicillium janthinellum and Fusarium oxysporum. Bioautography assay was used to determine the presence and number of antifungal compounds of the plant extracts. Bioassay-guided fractionation using column chromatography of the chloroform extract led to the isolation of four antifungal compounds. Nuclear Magnetic Resonance (NMR) spectroscopy, Mass Spectrometry (MS) and Electron Impact Mass Spectrometry (EIMS) were used for the identification of antifungal compounds. Cytotoxicity of the chloroform crude extract and isolated compounds was determined using the MTT (3-(4,5-dimethylthiazol)-2,5-diphenyl tetrazolium bromide) assay against Vero monkey kidney cells.

Results

Compound 1 was identified as ursolic acid, while compounds 2, 3 and 4 were not identified conclusively owing to the presence of mixtures of long chain fatty acids. Compounds 3 and 4 had good antifungal activity against Aspergillus parasiticus and Penicillium janthinellum with MIC values of 10 and 16 µg/ml respectively. Compound 2 and ursolic acid had some activity with MIC values ranging between 20 and 250 µg/ml. The crude extract was less toxic to the Vero cells (LC₅₀=82 µg/ml) than ursolic acid (LC₅₀=25 µg/ml). Compounds 2 and 3 were not toxic at the highest concentration tested (LC₅₀=200 µg/ml). Compound 4 was the most toxic to the cells with an LC₅₀ of 35 µg/ml.

Conclusions

The results support the traditional use of Breonadia salicina for antifungal applications, and demonstrate the potential value of developing antifungal compounds from plant natural products. Indications of toxicity should be evaluated at an early stage as the selectivity of the product in affecting fungi preferentially to plant or mammalian cells should be identified when assessing the potential usefulness of the product.     

South African Helichrysum species: a review of the traditional uses, biological activity and phytochemistry

Aims of the study

In South Africa, the genus Helichrysum is widely used in traditional medicine. The uses are well documented although renaming of species and the resulting confusing taxonomic nomenclature may cause uncertainty as to which specific species was referred to in some reports. The aim of this paper is to present a collated and coherent overview of the documented traditional uses of Helichrysum species and to update the botanical identity of previously studied species.

Materials and methods

Databases (Scifinder, ISI Web of Knowledge) and several books were used to collect in information on South African Helichrysum species.

Results

The traditional uses, chemistry and biological activity of Helichrysum species have been summarized. It was attempted to give clarity as to exactly which species is refer to in the ethnobotanical literature.

Conclusions

Although a large number of ethnopharmacological uses have been documented and the chemistry of the genus has been studied extensively, only a few South African species have been investigated for their biological activity.     

Antimicrobial activity of the essential oil and extracts of Cordia curassavica (Boraginaceae)

In traditional Mexican medicine Cordia curassavica (Jacq) Roemer & Schultes is used to treat gastrointestinal, respiratory and dermatological disorders in Zapotitlán de las Salinas, Puebla (México). The aim of this work was to investigate antimicrobial activity of the essential oil, obtained by using Clevenger distillation apparatus, and hexane, chloroform and methanol extracts from aerial parts of Cordia curassavica. Antimicrobial activity was evaluated against 13 bacteria and five fungal strains. The oil and extracts exhibited antimicrobial activity against Gram-positive and Gram-negative bacteria and five fungal strains. Sarcina lutea and Vibrio cholerae were the strains more sensitive to the essential oil effect (MIC=62 microg/mL) and Vibrio cholerae for the hexane extract (MIC=125 microg/mL). Rhyzoctonia solani was the strain more sensitive to the essential oil effect (IC(50)=180 microg/mL) and Trichophyton mentagrophytes for the hexane extract (IC(50)=230 microg/mL). The essential oil was examined by GC and GC-MS. A total 11 constituents representing 96.28% of the essential oil were identified: 4-methyl,4-ethenyl-3-(1-methyl ethenyl)-1-(1-methyl methanol)cyclohexane (37.34%), beta-eudesmol (19.21%), spathulenol (11.25%) and cadina 4(5), 10(14) diene (7.93%) were found to be the major components. The present study tends to confirm the use in the folk medicine of Cordia curassavica in gastrointestinal, respiratory and dermatological diseases.     

South African Salvia species: a review of biological activities and phytochemistry

The genus Salvia (sage) belongs to the Lamiaceae and encompasses 900 species worldwide of which ca. 26 indigenous species are found in southern Africa. Salvia is the largest genus in this family and constitutes almost one quarter of the Lamiaceae. In South Africa, the majority of Salvia species are distributed predominantly in the Cape region. Salvia species are used in many parts of the world to treat various conditions. Many sages, if not all, form an integral part of traditional healing in South Africa particularly in regions where they occur in abundance. Several species are used to treat microbial infections, cancer, malaria, inflammation, loss of memory and to disinfect homes after sickness. Despite the extensive traditional use and the general interest in phytoconstituents of Salvia it remains ironic that research on the South African counterparts has until recently been neglected. The review aims to collate recent research results on the phytochemistry and pharmacological properties of indigenous species. Bio-active compounds with antiplasmodial and antibacterial activities have been isolated and structurally elucidated from Salvia chamelaegnea, Salvia radula and Salvia verbenaca. The essential oil composition of Salvia showed the dominance of monoterpene hydrocarbons, oxygen-containing monoterpenes and oxygen- containing sesquiterpenes. Salvia runcinata is identified as an alternative source of natural alpha-bisabolol. Many pharmacological activities are summarised (anti-oxidant, antimicrobial, antiplasmodial, analgesic, antipyretic, anticancer, anti-inflammatory and antinociceptive) as a first attempt to provide scientific support for past and present local traditional uses.     

Antibacterial and antifungal activity of Cassia fistula L.: an ethnomedicinal plant

Hexane, chloroform, ethyl acetate, methanol and water extracts from the flower of Cassia fistula (an ethnomedicinal plant) were tested against bacteria and fungi. All the extracts exhibited antibacterial activity against Gram-positive organisms with minimum inhibitory concentrations (MIC) between 0.078 and 2.5 mg/ml. Among the Gram-negative bacteria, only Pseudomonas aeruginosa was susceptible to the extracts. Ethyl acetate crude extract was fractionated using chromatographic techniques. A crystal was isolated, which was confirmed as 4-hydroxy benzoic acid hydrate using X-ray crystallography. It exhibited antifungal activity against Trichophyton mentagrophytes (MIC 0.5 mg/ml) and Epidermophyton floccosum (MIC 0.5 mg/ml).     

Antimicrobial and general toxicity activities of Gymnosperma glutinosum: a comparative study

Gymnosperma glutinosum (Spreng.) Less (Asteraceae) is an important, and an effective herbal medicine which is wide used for the treatment of diarrhoea in Mexico. We examined and compared the antibacterial and antifungal activities through the dilution method and for general toxicity activity by the brine shrimp lethality assay of two samples of Gymnosperma glutinosum from two localities of Mexico: San Rafael-Coxcatlan (Puebla State) and Tepeji del Rio (Hidalgo State). In addition, two bioactive compounds (-)-17-hydroxy-neo-clerod-3-en-15-oic acid (1) and 5,7-dihydroxy-3,6,8,2',4',5'-hexamethoxyflavone (2) were isolated. From the hexane extract from both places was obtained a MeOH partition M(2). M(2) of Tepeji del Rio showed the least MICs (<125 microg/ml) in the majority of the bacterial strains. Sarcina lutea was the most sensitive bacteria (MIC< 125 microg/ml). The hexane extract of both localities showed antifungal activity against all tested fungi. San Rafael's hexane extract was significant more activity than Tepeji del Rio. Aspergillus niger (IC(50)=23.79 microg/ml) and Trichophyton mentagrophytes (IC(50)=90.25 microg/ml) were the more sensitive fungus strains. The strongest general toxicity activity was observed with the M(2) partition from Tepeji del Rio (LC(50)=503.7 microg/ml). The results obtained in this investigation, showed differences between the antimicrobial activities of the samples of plants collected in San Rafael (Puebla) and Tepeji del Rio (Hidalgo).     

Minimum inhibitory concentrations of medicinal plants used in Northern Peru as antibacterial remedies

Aim

The plant species reported here are traditionally used in Northern Peru to treat bacterial infections, often addressed by the local healers as “inflammation”. The aim of this study was to evaluate the minimum inhibitory concentration (MIC) of their antibacterial properties against Gram-positive and Gram-negative bacteria.

Materials and methods

The antimicrobial activity of ethanolic and water extracts of 141 plant species was determined using a deep-well broth microdilution method on commercially available bacterial strains.

Results

The ethanolic extracts of 51 species inhibited Escherichia coli, and 114 ethanolic extracts inhibited Staphylococcus aureus. In contrast, only 30 aqueous extracts showed activity against Escherichia coli and 38 extracts against Staphylococcus aureus. The MIC concentrations were mostly very high and ranged from 0.008 to 256 mg/ml, with only 36 species showing inhibitory concentrations of <4 mg/ml. The ethanolic extracts exhibited stronger activity and a much broader spectrum of action than the aqueous extracts. Hypericum laricifolium, Hura crepitans, Caesalpinia paipai, Cassia fistula, Hyptis sidifolia, Salvia sp., Banisteriopsis caapi, Miconia salicifolia and Polygonum hydropiperoides showed the lowest MIC values and would be interesting candidates for future research.

Conclusions

The presence of antibacterial activity could be confirmed in most species used in traditional medicine in Peru which were assayed in this study. However, the MIC for the species employed showed a very large range, and were mostly very high. Nevertheless, traditional knowledge might provide some leads to elucidate potential candidates for future development of new antibiotic agents.     

Antimicrobial potential of Glycyrrhiza glabra roots

The present study was aimed to investigate antimicrobial potential of Glycyrrhiza glabra roots. Antimycobacterial activity of Glycyrrhiza glabra was found at 500 microg/mL concentration. Bioactivity guided phytochemical analysis identified glabridin as potentially active against both Mycobacterium tuberculosis H(37)Ra and H(37)Rv strains at 29.16 microg/mL concentration. It exhibited antimicrobial activity against both Gram-positive and Gram-negative bacteria. Our results indicate potential use of licorice as antitubercular agent through systemic experiments and sophisticated anti-TB assay.     

Antimicrobial and anti-inflammatory activity of four known and one new triterpenoid from Combretum imberbe (Combretaceae)

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.     

Antimicrobial compounds from Alpinia conchigera

Ethnopharmacological relevance

The rhizome of Alpinia conchigerahas been used as a condiment in the northern states of Peninsular Malaysia and occasionally in folk medicine in the east coast to treat fungal infections. In some states of Peninsular Malaysia, the rhizomes are consumed as a post-partum medicine and the young shoots are prepared into a vegetable dish. This study aimed to investigate the chemical constituents of the pseudostems and rhizomes of Malaysian Alpinia conchigera and to evaluate the antimicrobial activity of the dichloromethane (DCM) extracts of the pseudostems, rhizomes and the isolated compounds against three selected fungi and five strains of Staphylococcus aureus.

Materials and methods

The dried and ground pseudostems (0.8 kg) and rhizomes (1.0 kg) were successively extracted in Soxhlet extractor using n-hexane, dichloromethane (DCM) and methanol. The n-hexane and DCM extracts of the pseudostem and rhizome were subjected to isolation and purification using column chromatography on silica gel using a stepwise gradient system (n-hexane to methanol). Briefly, a serial two fold dilutions of the test materials dissolved in DMSO were prepared prior to addition of 100 μl overnight microbial suspension (108 cfu/ml) followed by incubation at 37 °C (bacteria) or 26 °C (dermatophytes and candida) for 24 h. The highest concentration of DMSO remaining after dilution (5%, v/v) caused no inhibition to bacterial/candida/dermatophytes’ growth. Antibiotic cycloheximide was used as reference for anticandidal and antidermatophyte comparison while oxacilin was used as reference for antibacterial testing. DMSO served as negative control. Turbidity was taken as indication of growth, thus the lowest concentration which remains clear after macroscopic evaluation was taken as the minimum inhibitory concentration (MIC).

Results

The isolation of n-hexane and DCM extracts of the rhizomes and pseudostems of Alpinia conchigera via column chromatography yielded two triterpenes isolated as a mixture of stigmasterol and β-sitosterol: caryophyllene oxide, chavicol acetate 1, p-hydroxy cinnamaldehyde 2, 1′S-1′-acetoxychavicol acetate 3, trans-p-coumaryl diacetate 4, 1′S-1′-acetoxyeugenol acetate 5, 1′-hydroxychavicol acetate 6, p-hydroxycinnamyl acetate 7 and 4-hydroxybenzaldehyde.The DCM extract of the rhizome of Alpinia conchigera indicated potent antifungal activity against Candida albicans, Microsporum canis and Trycophyton rubrum with MIC values of 625 μg/ml, 156 μg/ml and 156 μg/ml, respectively. It also showed significant inhibitory activity with MIC values between 17.88 and 35.75 μg/ml against the mutant Staphylococci isolates MSSA, MRSA and Sa7.Amongst the isolated compounds, the lowest inhibition observed were of 1′S-1′-acetoxyeugenol against the dermatophytes (MIC 313 μg/ml) followed by trans-p-coumaryl diacetate against both dermatophytes and candida (MIC 625 μg/ml). The compound p-hydroxycinnamyl acetate strongly inhibited Staphylococcusaureus strain VISA (MIC 39 μg/ml) followed by trans-p-coumaryl diacetate and 1′-hydroxychavicol acetate with MIC value of 156 μg/ml.

Conclusion

In conclusion, the observed antibacterial, anticandidal and antidermatophyte activity of the extracts and compounds obtained from the rhizome confirm the traditional use of Alpinia cochigera rhizome in the treatment of skin infection.     

In vitro antifungal activity of indirubin isolated from a South Indian ethnomedicinal plant Wrightia tinctoria R. Br.

Ethnopharmacological relevance

Acalypha indica, Cassia alata, Lawsonia inermis, Punica granatum, Thespesia populnea and Wrightia tinctoria are folklore medicines extensively used in the treatment of ringworm infections and skin related diseases in Tamil Nadu, India.

Aim

The present study was designed to investigate the in vitro antifungal activity of certain medicinal plants and the pure compound indirubin isolated from Wrightia tinctoria.

Materials and methods

The hexane, chloroform, methanol and ethanol extracts of six different plants were investigated against dermatophytes, non-dermatophytes and yeasts. Chloroform extract of Wrightia tinctoria leaf was fractionated using column chromatography and the major compound was identified using spectroscopic techniques. Antifungal activity was studied by spore germination test using agar dilution method. The minimum inhibitory concentration (MIC) was determined using broth microdilution method.

Results

Wrightia tinctoria showed promising activity against dermatophytic and non-dermatophytic fungi. Leaf chloroform extract showed activity at 0.5 mg/ml against Trichophyton rubrum, Epidermophyton floccosum, Aspergillus niger and Scopulariopsis brevicaulis. The major compound, identified as indirubin, exhibited activity against dermatophytes such as Epidermophyton floccosum (MIC = 6.25 μg/ml); Trichophyton rubrum and Trichophyton tonsurans (MIC = 25 μg/ml); Trichophyton mentagrophytes and Trichophyton simii (MIC = 50 μg/ml). It was also active against non-dermatophytes (Aspergillus niger, Candida albicans and Cryptococcus sp.) within a MIC range of 0.75-25 μg/ml.

Conclusion

The indole compound indirubin from Wrightia tinctoria showed antifungal activity and may be useful in the treatment of dermatophytosis.     

The in vitro biological activity of selected South African Commiphora species

Ten South African Commiphora (Burseraceae) species were investigated to validate their use in traditional healing rites. The leaf and stem extracts of each species were analysed for the anti-oxidant (ABTS and DPPH assays), antimicrobial (MIC and death kinetic assays), anti-inflammatory (5-LOX assay), anticancer (SRB assay) properties, as well as the cytotoxic effects (tetrazolium-based assay). The best anti-oxidant activity (ABTS assay) was observed for the stem extracts of Commiphora tenuipetiolata IC(50)=5.10 microg/ml), Commiphora neglecta (IC(50)=7.28 microg/ml) and Commiphora mollis (IC(50)=8.82 microg/ml). Extracts generally exhibited poor anti-oxidant activity in the DPPH assay, with the exception of Commiphora schimperi (stem), Commiphora neglecta (stem), Commiphora tenuipetiolata (stem and leaf), and Commiphora edulis (stem), with IC(50) values ranging between 7.31 and 10.81 microg/ml. The stem extracts exhibited moderate to good 5-LOX inhibitory activity with Commiphora pyracanthoides (stem) displaying the greatest inhibitory effect (IC(50)=27.86+/-4.45 microg/ml). For the antimicrobial (MIC) assay, a greater selectivity was exhibited by the extracts against the Gram-positive bacteria (0.01-8.00 mg/ml) and the yeasts (0.25-8.00 mg/ml) than against the Gram-negative bacteria (1.00-8.00 mg/ml). Using death kinetic studies (time-kill studies), the rate at which Commiphora marlothii (stem) kills Staphylococcus aureus over a 24h period was determined. Mostly, a concentration-dependent antibacterial activity was observed beginning after ca. 30 min. All concentrations exhibited antibacterial activity, with complete bactericidal effect achieved by the 24(th) hour. The most active Commiphora species against the HT-29 cells (SRB anticancer assay) were Commiphora glandulosa (leaf and stem) and Commiphora marlothii (leaf). The MCF-7 cells (SRB anticancer assay) exhibited the highest sensitivity to indigenous Commiphora species, with Commiphora edulis (leaf and stem), Commiphora glandulosa (leaf and stem), Commiphora marlothii (leaf), Commiphora pyracanthoides (leaf and stem), Commiphora schimperi (stem), and Commiphora viminea (stem) all possessing a percentage inhibition greater than 80% at 100 microg/ml. Commiphora glandulosa (leaf and stem) and Commiphora pyracanthoides (leaf and stem) were the two most active species against the SF-268 cells (SRB anticancer assay), with IC(50) values ranging between 68.55+/-2.01 and 71.45+/-1.24 microg/ml. The majority of the Commiphora extracts were largely non-cytotoxic against Graham human kidney epithelial cells when investigated in the MTT assay.     

黔产青皮挥发油化学成分及抑菌活性研究

目的:对黔产青皮的挥发油化学成分及抑菌活性进行研究。方法:利用水蒸气蒸馏法从青皮中提取挥发油,用气相色谱-质谱联用法(GC-MS)分析鉴定成分并进行抑菌活性研究试验。结果:从挥发油中共鉴定出49个化学成分,占挥发油色谱总峰面积的96.39%;抑菌活性研究表明青皮挥发油对5种受试菌有一定的抑制作用,对枯草芽孢杆菌、大肠埃希氏菌、伤寒沙门氏菌、金黄色葡萄球菌和藤黄微球菌的最小抑菌浓度分别为0.65～1.25,1.25,0.62～1.25,0.62,0.31～0.62 g.L-1。结论:青皮挥发油的主要成分为萜类,具有一定的抗菌活性。     

Antibacterial and antifungal activity of Flindersine isolated from the traditional medicinal plant, Toddalia asiatica (L.) Lam.

Aim of the study

The leaves and root of Toddalia asiatica (L.) Lam. (Rutaceae) are widely used as a folk medicine in India. Hexane, chloroform, ethyl acetate, methanol and water extracts of Toddalia asiatica leaves and isolated compound Flindersine were tested against bacteria and fungi.

Materials and methods

Antibacterial and antifungal activities were tested against bacteria and fungi using disc-diffusion method and minimum inhibitory concentrations (MICs). The compound was confirmed using X-ray crystallography technique.

Results

Antibacterial and antifungal activities were observed in ethyl acetate extract. One active principle Flindersine (2,6-dihydro-2,2-dimethyl-5H-pyrano [3,2-c] quinoline-5-one-9cl) was isolated from the ethyl acetate extract. The MIC values of the compound against bacteria Bacillus subtilis (31.25 μg/ml), Staphylococcus aureus (62.5 μg/ml), Staphylococcus epidermidis (62.5 μg/ml), Enterococcus faecalis (31.25 μg/ml), Pseudomonas aeruginosa (250 μg/ml), Acinetobacter baumannii (125 μg/ml) and fungi Trichophyton rubrum 57 (62.5 μg/ml), Trichophyton mentagrophytes (62.5 μg/ml), Trichophyton simii (62.5 μg/ml), Epidermophyton floccosum (62.5 μg/ml), Magnaporthe grisea (250 μg/ml) and Candida albicans (250 μg/ml) were determined.

Conclusions

Ethyl acetate extract showed promising antibacterial and antifungal activity and isolated compound Flindersine showed moderate activity against bacteria and fungi.     

Antifungal activity of Brazilian medicinal plants involved in popular treatment of mycoses

A survey of medicinal plants used to treat common mycoses was done in the Curituba district, Sergipe State, Brazil. One hundred inhabitants were interviewed by health agents and traditional healers. Four different plants were the most cited (more than 50% of the citations): Ziziphus joazeiro, Caesalpinia pyramidalis, Bumelia sartorum and Hymenea courbaril. The aqueous extracts obtained following traditional methods and using different parts of these plants, were submitted to drop agar diffusion tests for primary antimicrobial screening. Only the water infusion extract of Ziziphus joazeiro and Caesalpinea pyramidalis presented a significant antifungal activity against Trichophyton rubrum, Candida guilliermondii, Candida albicans, Cryptococcus neoformans and Fonsecaea pedrosoi, when compared to the antifungal agent amphotericin B. The minimal inhibitory concentration (MIC) of the bioactive extracts was evaluated by the microdilution method. Best activity with a MIC of 6.5 microg/ml for both extracts was observed against Trichophyton rubrum and Candida guilliermondii. Ziziphus joazeiro and Caesalpinea pyramidalis extracts presented also low acute toxicity in murine models. The present study validates the folk use of these plant extracts and indicates that they can be effective potential candidates for the development of new strategies to treat fungal infections.     

白木香果皮提取物的抗菌活性

目的:为开发利用白木香果皮资源,对其提取物进行抗菌活性评价。方法:用三氯甲烷对白木香果皮进行提取,提取物分别采用滤纸片法和生长速率法对不同细菌和真菌进行抗菌活性测定,并采用连续稀释法测定其最低抑菌浓度。结果:白木香果皮提取物对金黄色葡萄球菌、枯草芽孢杆菌、铜绿假单胞菌有显著抑制作用,最小的抑菌浓度分别为6.25,625,12.5 g.L-1,对大肠杆菌则没有抑制效果;对绿色木霉、黑曲霉、黄曲霉也有明显的抑制作用,最小的抑菌浓度分别为6.25,6.25,12.5 g.L-1。结论:白木香果皮三氯甲烷提取物具有显著的抗菌活性,值得开发利用。     

Medicinal plants from the Yanesha (Peru): Evaluation of the leishmanicidal and antimalarial activity of selected extracts

Aim of the study

Ninety-four ethanolic extracts of plants used medicinally by the Yanesha, an Amazonian Peruvian ethnic group, for affections related to leishmaniasis and malaria were screened in vitro against Leishmania amazonensis amastigotes and against a Plasmodium falciparum chloroquine resistant strain.

Materials and methods

The viability of Leishmania amazonensis amastigote stages was assessed by the reduction of tetrazolium salt (MTT) while the impact on Plasmodium falciparum was determined by measuring the incorporation of radio-labelled hypoxanthine.

Results and conclusions

Six plant species displayed good activity against Plasmodium falciparum chloroquine resistant strain (IC₅₀ < 10 μg/ml): a Monimiaceae, Siparuna aspera (Ruiz & Pavon), A. DC., two Zingiberaceae, Renealmia thyrsoidea (Ruiz & Pavon) Poepp. & Endl. and Renealmia alpinia (Rottb.), two Piperaceae (Piper aduncum L. and Piper sp.) and the leaves of Jacaranda copaia (Aubl.) D. Don (Bignoniaceae).Eight species displayed interesting leishmanicidal activities (IC₅₀ < 10 μg/ml): Carica papaya L. (Caricaceae), Piper dennisii Trel (Piperaceae), Hedychium coronarium J. König (Zingiberaceae), Cestrum racemosum Ruiz & Pav. (Solanaceae), Renealmia alpinia (Rottb.) Zingiberaceae, Lantana sp. (Verbenaceae), Hyptis lacustris A. St.-Hil. ex Benth. (Lamiaceae) and Calea montana Klat. (Asteraceae). Most of them are used against skin affections by Yanesha people.Results are discussed herein, according to the traditional use of the plants and compared with data obtained from the literature.     

Evaluation of antimicrobial activity of ethanol extract and compounds isolated from Trichodesma indicum (Linn.) R. Br. root

Ethnopharmacological relevance

The roots are reportedly used to treat diarrhoea, dysentery, leprosy, skin diseases and fever.

Aim of study

The aim of present study was to investigate the in vitro antimicrobial potential of ethanol extract of Trichdesma indicum root, and its purified compounds and to validate scientifically its use in traditional medicine.

Material and methods

The root of Trichdesma indicum was extracted with ethanol and subjected to chromatographic separation for isolation of phytochemical compounds. Structures of isolated compounds were elucidated by spectroscopic methods. The antimicrobial activities of the ethanol extract of T. indicum and isolated compounds were primarily evaluated by a disc diffusion test. The anti-microbial efficacy of the ethanol extract or isolated compounds was then assessed in vitro by determining minimal inhibition concentration (MIC) and minimal bactericidal or fungicidal concentration (MBC/MFC).

Results

n-Decanyl laurate (1), n-tetradecanyl laurate (2), n-nonacosanyl palmitate (3), stigmast-5-en-3β-ol-21(24)-olide (4), n-pentacos-9-one (5), n-dotriacont-9-one-13-ene (6), stigmast-5-en-3β-ol-23-one (7) and lanast-5-en-3β-D-glucopyranosyl-21 (24)-olide (8) were isolated from ethanol extract of T.indicum. The ethanol extract and isolated compounds (1–8) showed varying degrees of antimicrobial activities. The ethanol extract exhibited potent growth inhibitory activity against S. aureus, B. subtilis and C. albicans with an MIC value of 19.2 μg/ml. Among all the isolated compounds, lanast-5-en-3β-D-glucopyranosyl-21 (24)-olide (8) displayed strongest antibacterial activity against S. aureus with MIC value of 2.4 μg/ml.

Conclusions

The results of present study provide ground basis for the potential use of the ethanol extract Trichodesma indicum root as well as the some of the isolated compounds in the treatment of infections associated with the studied microorganisms.