The anti-dermatophyte activity of Commiphora molmol

Context: Commiphora molmol Engl (Burseraceae) or myrrh has been traditionally used for the treatment of skin fungal infections.

Objective: This study evaluates the antifungal activity of myrrh ethanol extract and essential oil against skin dermatophytes.

Materials and methods: The antifungal evaluations were performed by the food poisoning technique (250?ppm) and micro-broth dilution assay (800–6.25?µg/mL) against Trichophyton rubrum, T. mentagrophytes, Microsporum canis, M. gypseum, and T. verrucosum. The chemical composition of myrrh oil and ethanol extract was analyzed by GC and GC-MS.

Results: Furanoeudesma 1,3-diene and menthofuran were the main components of myrrh oil, while 2-tert-butyl-1,4-naphthoquinone, benzenemethanol,3-methoxy-α-phenyl, and curzerene were the main components of myrrh ethanol extract. The inhibitory effect of myrrh oil and ethanol extract against dermatophytes were 43.1–61.6% and 12.5–27.5%, respectively. The MIC and MFC values of myrrh oil were 25–100 and 25–200?µg/mL while these amounts for ethanol extract were 25–400 and 25–400?µg/mL, respectively. Therefore, myrrh oil had higher antifungal activity than that of the ethanol extract. Both extracts showed good anti-elastase activity.

Conclusion: The results of our investigation confirmed the traditional uses of C. molmol as a poultice for the treatment of cutaneous fungal infections.     

In Vitro Antibacterial and Antifungal Activities of Extracts and Compounds from Uvaria scheffleri

Petroleum ether, dichloromethane, and ethanolic extracts of the stem bark and leaves of Uvaria scheffleri Diels (Annonaceae) exhibited antifungal activity against Aspergillus niger (wild strain), Aspergillus fumigatus (wild strain), and a Penicillium species (wild strain). The ethanol extract of the stem bark was also active against Candida albicans (Strain H6392). The dichloromethane extract of the leaves showed the highest antifungal activity and in addition it showed antibacterial activity against Staphylococcus aureus (NCTC 6571). Fractionation of the dichloromethane extract of the leaves yielded nine known compounds. They included a 1 : 1 mixture of stigmasterol (1) and β-sitosterol (2), which showed antifungal activity against Candida albicans. Others were 3-farnesylindole (3), 2′,6′-dihydroxy-3′,4′-dimethoxy-chalcone (4), 2′-hydroxy-3′,4′,6′-trimethoxychalcone (5), 5-hydroxy-7,8-dimethoxyflavanone (6), 5,7,8-trimethoxyflavanone (7), and a 3 : 2 mixture of 2′,6′-dihydroxy-4′-methoxychalcone (8) and 5,7-dihydroxyflavone (9). Compound 7 and the mixture of compounds 8 and 9 showed antibacterial activity against Escherichia coli (NCTC 10418, MIC 125 µg/ml) and Staphylococcus aureus (MIC 125 µg/ml), respectively. The mixture of compounds 8 and 9 was also active against Candida albicans (MIC 31.25 µg/ml), Aspergillus niger, Aspergillus fumigatus, and the Penicillium species (MIC 1000 µg/ml). We conclude that Uvaria scheffleri extracts contain compounds with antifungal and antibacterial activity. The activities observed in this study are weak. Based on previous studies, it is being speculated that, possibly, the most active compounds were lost during fractionation. Further work to isolate more antifungal and antibacterial compounds is suggested.     

Antimicrobial Activity of Methanol Extracts of Mosses from Serbia

Antibacterial and antifungal activity of methanol extracts of the mosses Pleurozium schreberi (Willd. Ex Brid.) Mitt. (Hylocomiaceae), Palustriella commutata (Hedw.) Ochyra (Amblystegiaceae), Homalothecium philippeanum (Spruce) Schimp. (Brachytheciaceae), Anomodon attenuatus (Hedw.) Huebener (Anomodontaceae), Rhytidium rugosum (Hedw.) Kindb. (Rhytidiaceae), Hylocomium splendens (Hedw.) Schimp. (Hylocomiaceae), Dicranum scoparium Hedw. (Dicranaceae), and Leucobryum glaucum (Hedw.) Ångstr. (Leucobryaceae), were tested against six bacterial and seven fungal species by microdilution and disc diffusion methods. The extract of A. attenuatus possessed the highest antibacterial activity (MIC of 1.25–5.0 mg/ml and MBC of 2.5–5.0 mg/ml), while L. glaucum extract showed the lowest activity (MIC of 20.0–25.0 mg/ml and MBC of 25.0 mg/ml). The best antifungal activity was obtained from P. schreberi extract (MIC of 0.5 mg/ml and MFC of 2.5–5.0 mg/ml, while the lowest antifungal potential was obtained from A. attenuatus (MIC 2.5–5 mg/ml and MFC 10 mg/ml). The extracts proved to be more active against Gram (+) bacteria than Gram (?) and showed strong antifungal activity.     

Anti-Candida albicans effectiveness of citral and investigation of mode of action

Context: Candidiasis is a mycosis caused by Candida species, which is of clinical importance due to the increase in resistant yeasts. Candida infection has been a serious health problem due to the inappropriate use of antibiotics. Therefore, it is necessary to study molecules with an antifungal action. Citral is a monoterpene with known pharmacological properties, including antimicrobial action.

Objective: The aim of this work was to determine the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of citral and the probable mode of action.

Materials and methods: The MIC of citral was determined by the broth microdilution method using Sabouraud dextrose medium. Additionally, the interference of citral in cell wall (sorbitol assay) and the binding of citral to ergosterol and cholesterol were studied, carried out by broth microdilution method.

Results: The MIC and MFC of citral were 512 and 1024 µg/mL, respectively. The MIC of amphotericin B was 1 µg/mL. The mechanism of action did not involve either the cell wall or ergosterol. However, the presence of cholesterol increased the MIC of citral to 1024 µg/mL, indicating there is some interaction between citral and cholesterol. Amphotericin B was used as the positive control, and it showed a high MIC in the presence of ergosterol (32 µg/mL), while in the presence of cholesterol MIC increased to 4 µg/mL.

Conclusion: Citral inhibits the growth of C. albicans. The probable mechanism of action did not involve the cell wall or ergosterol. Citral is able to interact with cholesterol. More studies are necessary to describe their effects completely.     

Antifungal activity of the Algerian Lawsonia inermis (henna)

Context: Lawsonia inermis Linn. (Lythraceae) or henna has been used since the earliest times as a medicine, preservative, and cosmetic. It has long been recommended in traditional medicine as an astringent, purgative, and abortifacient.

Objective: Lawsone and six extracts of L. inermis plant, used by Algerian traditional healers to treat infectious diseases, were screened for their antifungal activity against filamentous fungi.

Materials and methods: Water and five organic extracts – DMSO, ethanol, chloroform, ethyl acetate, and di-ethyl ether – of L. inermis leaves, collected in the area of Adrar (Algeria), were prepared by soaking 25?g of powdered plant in 100?mL of solvent. The extracts were screened for antifungal activity using the poisoned food technique against five filamentous fungi.

Results: Results demonstrated that the best yield (8.03%) was obtained with the ethanol extract. The commercial lawsone showed potentially interesting MICs against the strains Fusarium oxysporum (12 µg/mL) and Aspergillus flavus (50 µg/mL). The ethanol extract showed the only interesting MIC (230 µg/mL of crude extract) against the strain F. oxysporum compared with other extracts.

Discussion and conclusion: These results suggest that the Algerian L. inermis plant has antifungal activity that can be related to the presence of lawsone in the leaves plant. The results can be exploited largely in research of new antifungal drugs.     

Antibacterial and Antifungal Activities of the Constituents of Flemingia paniculata.

Abstract

A salicylic acid derivative (1), a cinnamaldehyde (2), and six isoflavones (3–8) from the stem bark of Flemingia paniculata. Wall. (Leguminosae) were tested for antibacterial (both Gram-positive and Gram-negative) and antifungal activities. All the compounds showed significant activities against the test organisms having MIC values in the range of 1.57–200 μ g/mL. The highest potency (MIC = 1.57 μ g/mL) was exhibited by 3 against Staphylococcus aureus..     

Bioactivity-guided isolation and structural characterization of the antifungal compound,plumbagin, from Nepenthes gracilis

Context: Despite several phytochemical studies of Nepenthes gracilis Korth (Nepenthaceae), the biological activities of this pitcher plant remain to be explored.

Objective: This study evaluates the antifungal activity of N. gracilis extracts, isolates, and characterizes its bioactive compound and evaluates the cytotoxicity of the isolated compound.

Materials and methods: Fresh leaves of N. gracilis were sequentially extracted. The fungistatic and fungicidal activities of the extracts were evaluated against six species of fungi of medical importance using a colorimetric broth microdilution method. The most active extract was fractionated by liquid–liquid partitioning and further purified by a preparative thin layer chromatography. Structural elucidation was carried out using FT-IR, GC-MS, and NMR. Cytotoxicity testing against rhesus monkey kidney epithelial cells (LLC-MK2) was assessed by a neutral red uptake (NRU) assay.

Results: The hexane extract, which showed the lowest minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC), both at 20?μg/mL against Candida albicans, Issatchenkia orientalis, and Trichophyton mentagrophytes, was subjected to bioactivity-guided fractionation. The isolated compound exhibited potent activity with the MIC values ranging from 2 to 31?μg/mL against all the fungi. The active compound was identified as plumbagin (5-hydroxy-2-methyl-naphthalene-1,4-dione). The 50% cytotoxicity concentration (CC₅₀) of plumbagin was 0.60?μg/mL.

Discussion and conclusion: The selectivity indices of plumbagin against all the fungi were less than 1.0, indicating that plumbagin is more toxic to mammalian than fungal cells. This study provides information on the antifungal properties of N. gracilis leaf extracts, as well as the antifungal and cytotoxicity properties of plumbagin.     

Click chemistry approach for bis-chromenyl triazole hybrids and their antitubercular activity

1,4‐Disubstituted bis‐chromenyl triazole hybrids 5a – m have been synthesized in a three‐step reaction sequence from 4‐(bromomethyl)‐2H‐chromen‐2‐ones 3a – m . The intermediate azides 4a – m underwent a regioselective 1,3‐dipolar cycloaddition with a 2H‐chromen‐2‐one linked acetylenic dipolarophile in the presence of Cu (II)/ascorbate/water/n‐butanol reaction medium. Three compounds 5h – j exhibited 6.25 μg/mL MIC against M. tuberculosis. Among the compounds screened for antifungal activity, lowest MIC of 6.25 μg/mL was observed for 5c against A. niger that also exhibited DNA cleavage observed by agarose gel electrophoresis. All the compounds were moderately active against both Gram‐positive and Gram‐negative bacterial strains. The cytotoxic effect of potent compounds on normal cells (V79 and HBL100) was assessed by MTT assay.     

Antifungal and antibacterial activities of different extracts of Harungana madagascariensis stem bark

The antifungal and antibacterial effects of the stem bark extracts of Harungana madagascariensis Lam. ex Poir. (Clusiaceae) were examined against nine microbial pathogens causing infections in both man and animals. Hexane (H), dichloromethane (D), chloroform (C), ethyl acetate (E), acetone (A), methanol (M), and water (W) extracts were tested in vitro through bioautography and minimum inhibitory concentrations (MIC) determination using the serial micro-dilution assays. Bioautographic results revealed the presence of eight different spots. Extract A exhibited the lowest MIC of 0.04?mg/mL against Microsporum canis, while water extract (W) and methanol (M) showed the highest MIC of 2.5?mg/mL against at least one of the tested fungi when compared to amphotericin B with 0.0625–1?g/mL. Sporotrichum schenckii was the most susceptible fungal pathogen with average MIC of 0.06?mg/mL, while the acetone extract (A) was the most active against three fungal organisms when compared with other extracts. Similarly, extracts D, C, E and A exhibited very high activity with low MIC values of 0.156–0.62?mg/mL, while M and W gave the highest values of 0.31–2.5?mg/mL on bacterial pathogens as compared to gentamicin (0.02–0.62 8?g/mL). The dichloromethane extract is the most active against bacteria with average MIC of 0.19?mg/mL, while Staphylococcus aureus is the most sensitive organism; that shows susceptibility at an average MIC of 0.34?mg/mL. These results provide promising information for the potential use of the crude extracts from the stem-bark of H. madagascariensis in the treatment of bacterial and fungal infections similar to what was obtained in the leaves.     

Antimicrobial and anti-inflammatory properties of Funtumia elastica

Context: Funtumia elastica (Preuss) Stapf. (Apocynaceae) has a long ethnopharmacological history for uses such as treatment of whooping cough, asthma, blennorhea, painful menstruation, fungal infections, and wounds.

Objective: To investigate the antimicrobial and anti-inflammatory properties of ethanol extracts from the leaves and stem bark of Funtumia elastica based on its ethnopharmacological uses and also determine the secondary metabolites present in the extracts.

Materials and methods: The antimicrobial activities of ethanol leaf and bark extracts of F. elastica were determined using the microdilution technique (MIC determination) and agar diffusion method using 10, 25, and 50?mg/mL concentrations against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, Candida albicans, Aspergillus flavus and Aspergillus niger as test organisms. Anti-inflammatory activities of the doses of extracts at 30, 100, and 300?mg/kg per body weight were determined by carrageenan-induced edema in the footpad of 7-day-old chicks and the foot volumes measured at hourly interval post-treatment for 5?h.

Results: The MIC ranges of both ethanol leaf and bark extracts against the test organisms were 125 (lowest MIC) to1550 µg/mL (highest MIC) and 125 (lowest MIC) to 1750 µg/mL (highest MIC), respectively. The ethanol leaf and bark extract of F. elastica showed significant anti-inflammatory activity (p ≤ 0.001) at 30, 100 and 300?mg/kg. Preliminary phytochemical screening revealed that F. elastica bark contains hydrolysable tannins, sapogenetic glycosides, steroids and saponins while the leaves contain hydrolysable tannins, flavonoids, starch and alkaloids. Tannin contents of the leaf and stem bark were 2.4 and 1.3% w/w (related to the dried material), respectively.

Discussion and conclusion: Both ethanol leaf and bark extracts of F. elastica showed antimicrobial and anti-inflammatory activities and these pharmacological properties may be responsible for the ethnomedicinal uses of the leaves and stem bark of the plant.     

Effects of β-caryophyllene and Murraya paniculata essential oil in the murine hepatoma cells and in the bacteria and fungi 24-h time–kill curve studies

Context: Orange Jessamine [Murraya paniculata L. (Rutaceae)] has been used worldwide in folk medicine as an anti-inflammatory, antibiotic and analgesic.

Objective: The objective of this study is to investigate the in vitro antioxidant, cytotoxic, antibacterial and antifungal activity and the time-kill curve studies of orange jessamine essential oil and β-caryophyllene, as well as the chemical composition of the essential oil.

Material and methods: The cytotoxic activity of M. paniculata and β-caryophyllene (7.8–500?μg/mL) was evaluated using the MTT assay on normal fibroblasts and hepatoma cells. The minimal inhibitory concentration and time–kill curves (24?h) were evaluated against those of Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, Enterococcus faecallis, Aspergillus (niger, fumigates and parasiticum) and F. solani by the broth microdilution method. The antioxidant activity was measured by the DPPH and ABTS assays. Chemical composition was evaluated by GC/MS analyses.

Results: GC/MS analyses identified 13 compounds, with β-caryophyllene as the major compound. The oil exhibited moderate antibacterial activity (MIC <1.0?mg/mL) and strong antifungal activity. Time–kill curve studies showed that either the essential oil or β-caryophyllene presented rapid bacterial killing (4?h for S. aureus) and fungicidal effect (2-4?h for F. solani); however, both displayed weak free radical scavenger capacity. The cytotoxic activity exhibited a prominent selective effect against hepatoma cancer cells (IC₅₀ value =63.7?μg/mL) compared with normal fibroblasts (IC₅₀ value =195.0?μg/mL), whereas the β-caryophyllene showed low cytotoxicity.

Discussion and conclusion: The experimental data suggest that the activities of M. paniculata essential oil are due to the synergistic action among its components.     

Investigation of the antifungal activity of carvacrol against strains of Cryptococcus neoformans

Background: Cryptococcus neoformans is the etiologic agent of opportunistic systemic fungal infection cryptococcosis, which affects individuals with compromised immune systems. Thus, natural products research has become important, since monoterpenes such as carvacrol, a promising molecule in the search antifungal agents, have shown significant biological activity.

Objective: The study aimed to investigate the antifungal activity and mode of action of carvacrol against strains of C. neoformans.

Methods: The minimum inhibitory concentration (MIC) was determined by microdilution method. Minimum fungicidal concentration (MFC) was performed by seeding technique on solid media. Studying the mode of action was performed using broth microdilution.

Results: The MIC ranged from 25 to 81?μg/mL and the MFC ranged from 25 to 102?μg/mL. Carvacrol bonded to exogenous ergosterol and cholesterol.

Discussion: The results suggest that carvacrol has antifungal activity against C. neoformans and its mode of action is related to fungal membrane instability.

Conclusions: The phytoconstituent carvacrol may eventually become a drug; however, further studies are needed to elucidate its mechanism.     

Synthesis and biological evaluation of quinolines,thiazolo[3,2-<Emphasis Type="Italic">a</Emphasis>]pyrimidines,thiadiazolo[3,2-<Emphasis Type="Italic">a</Emphasis>]pyrimidines and triazolo[3,4-<Emphasis Type="Italic">b</Emphasis>][1,3,4]thiadiazepines as antimicrobial agents

Series of quinolines, thiazolo[3,2-a]pyrimidines, thiadiazolo[3,2-a]pyrimidines and triazolo[3,4-b][1,3,4]thiadiazepines were synthesized by the reaction of amino compound, aromatic aldehyde and malononitrile/ethyl cyanoacetate, using 2-[5-(4-methoxyphenyl)-4H-1,2,4-triazol-3-ylthio]acetic acid as an organocatalyst in water–ethanol mixture. Synthesized compounds were evaluated for in vitro antibacterial and antifungal activities against three fungal and five bacterial strains. Some of them exhibited good activity in comparison with the standard fluconazole and streptomycin such as compound 16h has shown best antifungal activity with MIC value of 60 µg/mL against A. niger and 12g exhibited best antibacterial activity with MIC value of 50 µg/mL against E. coli.     

Antimicrobial activity of confertifolin from Polygonum hydropiper

Confertifolin (6,6,9a-trimethyl-4,5,5a,6,7,8,9,9a-octahydronaphtho[1,2-c] furan-3 (1H)-one) was isolated from the essential oil of Polygonum hydropiper L. (Polygonaceae) leaves using column chromatography. Confertifolin showed activity both in bacteria and fungi. The lowest MIC for bacteria was observed against Enterococcus faecalis (31.25 μg/mL). Significant MIC for fungi was observed against Scopulariopsis sp (7.81 μg/mL), Curvularia lunata (7.81 μg/mL), Epidermophyton floccosum (7.81 μg/mL), Trichophyton mentagrophytes (16.62 μg/mL), Trichophyton rubrum (MTCC 296) (16.62 μg/mL), Aspergillus niger (31.25 μg/mL), Botrytis cinerea (31.25 μg/mL) Magnaporthe grisea (62.5 μg/mL), Trichophyton simii (125 μg/mL) and Trichophyton rubrum (clinical isolate) (125 μg/mL).     

Reversal of fluconazole resistance induced by a synergistic effect with Acca sellowiana in Candida glabrata strains

Context: The increased incidence of non-albicans Candida (NAC) resistant to fluconazole (FLZ) makes it necessary to use new therapeutic alternatives. Acca sellowiana (O.berg) Burret (Myrtaceae) is a guava with several proven biological activities. The interaction with fluconazole can be a feasible alternative to overcome this resistance.

Objective: This study evaluates the in vitro antifungal activity of fractions obtained from the lyophilized aqueous extract of the leaves of A. sellowiana against resistant strains of NAC.

Materials and methods: The antifungal activity of the fractions was evaluated at 500?μg/mL by microdilution method. Checkerboard assay was performed to determine the effect of the combination of the F2 fraction and antifungal at concentrations: MIC/4, MIC/2, MIC, MIC?×?2 and MIC?×?4.

Results: Candida glabrata showed the lowest MIC values (500–3.90?μg/mL) and the F2 active fraction was the most effective. The association of F2 with FLZ showed a strong synergistic effect (FICI?≤?0.5) against 100% of C. glabrata resistant isolates. Moreover, the F2 active fraction has demonstrated that probably acts in the cell wall of these yeasts. There was no observed acute dermal toxicity of lyophilized aqueous extract of leaves of A. sellowiana on pig ear skin cells.

Discussion and conclusion: The interaction between substances present in the F2 active fraction is possibly responsible for the antifungal activity presented by this fraction. This study is unprecedented and suggests that the combination of F2 active fraction and FLZ might be used as an alternative treatment for mucocutaneus infections caused by C. glabrata resistant.     

Screening of in vitro antimicrobial activity of plants used in traditional Indonesian medicine

Context: In many regions of Indonesia, there are numerous traditional herbal preparations for treatment of infectious diseases. However, their antimicrobial potential has been poorly studied by modern laboratory methods.

Objective: This study investigates in vitro antimicrobial activity of 49 ethanol extracts from 37 plant species used in Indonesian traditional medicine for treatment against Candida albicans, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus.

Materials and methods: The plants were collected from the Biopharmaca collection garden, Bogor, Indonesia. The plant material was dried, finely grounded, extracted using ethanol, concentrated, and the dried residue was dissolved in 100% DMSO. Antimicrobial activity was determined in terms of a minimum inhibitory concentration (MIC) using a broth microdilution method in 96-well microplates.

Results: The extract of Orthosiphon aristatus (Blume) Miq. (Lamiaceae) leaf produced the strongest antimicrobial effect, inhibiting the growth of C. albicans (MIC 128?μg/mL), S. aureus (MIC 256?μg/mL), E. faecalis (MIC 256?μg/mL) and P. aeruginosa (MIC 256?μg/mL). The leaf extract of Woodfordia floribunda Salisb. (Lythraceae) also exhibited significant effect against C. albicans (MIC 128?μg/mL), S. aureus (MIC 256?μg/mL) and E. faecalis (MIC 256?μg/mL). Rotheca serrata (L.) Steane &; Mabb. (Lamiaceae) leaf extract inhibited the growth of S. aureus (MIC 256 µg/mL) and C. albicans (MIC 256 µg/mL).

Discussion and conclusions: The leaf extract of O. aristatus and W. floribunda exhibited a significant anti-candidal effect. Therefore, both of these plants can serve as prospective source materials for the development of new anti-candidal agents.     

Antibacterial and modulatory effect of Stryphnodendron rotundifolium

Context: Stryphnodendron rotundifolium Mart. (Leguminosae), a tree in Northeast Brazil (Chapada do Araripe), is used in popular medicine to treat different processes such as inflammation and infectious diseases, mainly caused by bacterial pathogens.

Objective: This study determined the modulatory and antimicrobial activity of the hydroethanol extract of dried stem bark, the most used form of this natural product, as a remedy by the traditional communities, against standard and clinical isolates of Escherichia coli and Staphylococcus aureus.

Material and methods: The antibacterial and modulatory activities of the hydroalcoholic extract from the leaves were obtained by maceration/hydrodistillation method and assayed by microdilution.

Results: In the microbiological assays, growth inhibition was demonstrated by this extract against the bacterial strains tested, with minimal inhibitory concentration (MIC) values of 512 µg/mL. However, when a subinhibitory concentration (MIC/8?=?64 µg/mL) was combined with conventional antimicrobial drugs (gentamicin, kanamycin, amikacin and neomycin), the extract showed a potentiating effect, reducing the MIC for all drugs assayed in a range between 312.5 and 2.4 µg/mL.

Conclusions: We indicate that the extract of S. rotundifolium showed potential synergistic antibiotic activity. With the results obtained, these extracts proved to be a promising source of antibacterial and modulatory agents.     

Subcutaneous antifungal screening of Latin American plant extracts against Sporothrix schenckii and Fonsecaea pedrosoi

Context: Subcutaneous mycoses are chronic infections caused by slow growing environmental fungi. Latin American plants are used in folk medicine to treat these afflictions. Moreover, the potential of the rich Latin American biodiversity for this purpose has not been fully explored.

Objectives: The aim of the study was to screen Latin American plant extracts against two species of subcutaneous fungi: Sporothrix schenckii and Fonsecaea pedrosoi.

Materials and methods: One hundred ninety-five organic extracts from 151 Latin American plants were screened against two subcutaneous fungi by the agar dilution method at a concentration of 100 µg/mL, and minimum inhibitory concentrations (MICs) of active extracts were determined. Positive (amphothericin B) and negative (50% ethanol) controls were used.

Results and discussion: Twenty eight extracts showed activity at ≤100 µg/mL. Of these, four extracts from Gnaphalium gaudichaudianum DC (Asteraceae), Plumeria rubra L (Apocynaceae), Tecoma stans (L.) Juss. ex Kunth. (Bignoniaceae), and Trichostigma octandum (L.), H. Walter showed activity against F. pedrosoi at MIC 12.5 µg/mL; and, four extracts from Bourreria huanita (Lex.) Hemsl. (Boraginaceae), Phytolacca bogotensis Kunth (Phytolaccaceae), Monnina xalapensis Kunth (Polygalaceae) and Crataegus pubescens (C. Presl) C. Presl (Rosaceae) against S. schenckii. This is the first report on antifungal activity of the Latin American plants against these two subcutaneous fungi.

Conclusion: S. schenkii and F. pedrosoi were inhibited by B. huanita (MIC: 12.5 and 25 µg/mL), G. gaudichaudianum (MIC: 50 and 12.5 µg/mL) and T. triflora (MIC: 25 µg/mL).     

Biological activities and DNA interactions of Amanita ovoidea

Abstract

Context: Amanita ovoidea (Bull.) Link (Amanitaceae) is a well-known species due to its pleasant aroma and flavor since ancient times in the worldwide. This species is also known in Turkey and people consume it extensively.

Objective: To evaluate medicinal importance of A. ovoidea for human health, to explain the effect of mushroom extracts on bacterial DNA, and to find preventive role on bacterial disease.

Materials and methods: Chloroform, acetone, and methanol extracts of A. ovoidea were tested for the antimicrobial activities against four Gram-positive bacteria, five Gram-negative bacteria, and yeast using a micro-dilution method. In addition, DNA binding, DNA cleavage activity, and restriction enzyme digestion of the methanol extract of A. ovoidea were examined at different concentrations (40.000–78.125?µg/mL).

Results: The highest minimum inhibitory concentration (MIC) value observed against the test micro-organisms was with the chloroform extract (MIC 19.5?µg/mL concentration) against Candida albicans. Other highest antimicrobial effects observed against the test micro-organisms were with the methanol extracts against Bacillus subtilis, Staphylococcus aureus, Listeria monocytogenes, Streptococcus pyogenes, Candida albicans, Klebsiella pneumoniae, Proteus vulgaris, and Salmonella enteritidis (MICs, 78?µg/mL concentrations). All concentrations reduced the mobility of plasmid DNA. BamHI and HindIII targeted specially to supercoils and cut them. Amanita ovoidea extract prevented cutting with HindIII by binding especially to the AA region in open circular DNA.

Discussion and conclusion: Present results demonstrated that A. ovoidea has excellent antimicrobial and antifungal activities by its DNA interaction activity on pBR322.     

浙新霉素对皮肤癣菌的体外抗真菌活性研究

目的：评价浙新霉素体外抗真菌活性。方法：采用CLSI推荐的M-38A方案测定浙新霉素对7种皮肤癣菌最小抑菌浓度（MIC）及最小杀菌浓度（MFC）。结果：浙新霉素对7种皮肤癣菌的MIC范围为0.125-2.000μg·ml^-1,MFC范围为0.250-4.000μg·ml^-1。结论：浙新霉素具有较强的抗真菌活性,能抑制和杀灭絮状表皮癣菌、红色毛癣菌、紫色毛癣菌、犬小孢子菌、须癣毛癣菌、断发毛癣菌、石膏样小孢子菌等多种皮肤癣菌。