Eliana Harue Endo

Potent antifungal activity of extracts and pure compound isolated from pomegranate peels and synergism with fluconazole against Candida albicans.

Activity-guided repeated fractionation of crude hydro alcoholic extract prepared from the fruit peel of Punica granatum on a silica-gel column yielded a compound that exhibited strong antifungal activity against Candida spp. Based on spectral analyses, the compound was identified as punicalagin. Punicalagin showed strong activity against Candida albicans and Candida parapsilosis, with MICs of 3.9 and 1.9 microg/ml, respectively. The combination of punicalagin and fluconazole showed a synergistic interaction. MIC for fluconazole decreased twofold when combined with the extract. The FIC index was 0.25. The synergism observed in disk-diffusion and checkerboard assays was confirmed in time-kill curves. The effect of punicalagin on the morphology and ultrastructure in treated yeast cells was examined by scanning and transmission electron microscopy. An irregular budding pattern and pseudohyphae were seen in treated yeasts. By transmission electron microscopy, treated cells showed a thickened cell wall, changes in the space between cell wall and the plasma membrane, vacuoles, and a reduction in cytoplasmic content. Since the punicalagin concentration effective in vitro is achievable in vivo, the combination of this agent with fluconazole represents an attractive prospect for the development of new management strategies for candidiasis, and should be investigated further in in vivo models.

Comparison of the bacteriological quality of tap water and bottled mineral water.

The bacteriological quality of tap water from municipal water supplies, 20-L bottles of mineral water from water dispensers and samples collected from new 20-L bottles of mineral water were comparatively studied. Total coliforms, termotolerant coliforms, Escherichia coli, fecal streptococci, Pseudomonas aeruginosa, Staphylococcus spp. and heterotrophic plate count were enumerated. The results showed that 36.4% of the tap water samples from municipal water systems and 76.6% of the 20-L bottles of mineral water from water dispensers were contaminated by at least one coliform or indicator bacterium and/or at least one pathogenic bacterium. The bacteriological quality of municipal tap water is superior when compared with the 20-L bottles of mineral water collected from water dispensers and samples collected from new 20-L bottles of mineral water before installation in the dispensers. This highlights the need for an improved surveillance system for the bottled water industry. For the municipal water systems, it is recommended to perform the Pseudomonas enumeration periodically, in addition to the routine data collected by most systems.

Antifungal activity of pomegranate peel extract and isolated compound punicalagin against dermatophytes

BackgroundDermatophyte species infect the epidermis and appendages, often with serious social and health-economic consequences. The hydroalcoholic extract of pomegranate fruit peel showed activity against the dermatophyte fungi Trichophyton mentagrophytes, T. rubrum, Microsporum canis and M. gypseum.MethodsHydroalcoholic extract was prepared with pomegranate peels. This crude extract was fractionated and submitted to liquid-liquid partition, resulting in an active fraction which was fractionated in a Sephadex LH-20 column, followed by a Lobar column. The structure of the active compound was established with the use of spectroscopic methods.ResultsThe crude extract of pomegranate fruit peel showed activity against the dermatophytes Trichophyton mentagrophytes, T. rubrum, Microsporum canis, and M. gypseum, with MICs values of 125μg/ml and 250μg/ml, respectively for each genus. Punicalagin was isolated and identified by spectroscopic analysis. The crude extract and punicalagin showed activity against the conidial and hyphal stages of the fungi. The cytotoxicity assay showed selectivity for fungal cells than for mammalian cells.ConclusionsThese results indicated that the crude extract and punicalagin had a greater antifungal activity against T. rubrum, indicating that the pomegranate is a good target for study to obtain a new antidermatophyte medicine.

Chemical Composition and Antimicrobial Properties of Piper ovatum Vahl

The chemical composition of the essential oil obtained from the leaves of Piper ovatum Vahl by hydrodistillation was analyzed by GC–MS. The main constituents found were δ-amorphene (16.5 %), cis-muurola-4(14),5-diene (14.29 %) and γ-muurolene (13.26%). The crude extracts and isolated compounds were screened for their antimicrobial activity. Hydroalcoholic extracts of different parts of Piper ovatum Vahl, essential oil and amides isolated from leaves were tested against Gram-positive and Gram-negative bacteria and Candida species. All extracts and amides were active against Bacillus subtilis and Candida tropicalis, including clinical strains. Essential oil was active against C. tropicalis. These amides showed an inhibitory effect on the adherence of C. tropicalis ATCC 28707 on cover glasses at 10 µg/mL, but did not show morphological alterations at the tested concentrations. Amides were identified as piperovatine and piperlonguminine, and showed MIC values of 15.6 and 31.2 µg/mL to B. subtilis and 3.9 µg/mL to C. tropicalis, and low toxic effects to Vero cells and macrophages.

Activity of spray-dried microparticles containing pomegranate peel extract against Candida albicans.

Pomegranate has attracted interest from researchers because of its chemical composition and biological properties. It possesses strong antioxidant activity, with potential health benefits, and also antimicrobial properties. The aim of this study was to produce microparticles containing pomegranate extract by the spray-drying technique, utilizing alginate or chitosan as encapsulating agents. Characterization and antifungal assays were carried out. Production yields were about 40% for alginate microparticles and 41% for chitosan. Mean diameters were 2.45 µm and 2.80 µm, and encapsulation efficiencies were 81.9% and 74.7% for alginate and chitosan microparticles, respectively. The spray-drying process preserved the antifungal activity against Candida albicans. These results could be useful for developing dosage forms for treating candidiasis, and should be further investigated in in vivo models.

Preliminary studies on the antibacterial activity of crude extracts and alkaloids from species of Aspidosperma

Screening tests of hydroethanolic crude extracts of six species of Aspidosperma (Apocynaceae) against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, and Pseudomonas aeruginosa were performed. Aspidosperma ramiflorum Muell. Arg. showed good activity against Bacillus subtilis with MIC and MBC of 15.7 and 125 μg/mL, moderate activity against Staphylococcus aureus with MIC and MBC of 250 and 500 μg/mL, and weak activity against Escherichia coli with MIC and MBC of 1000 μg/mL. Aspidosperma pyricolum Muell. Arg. (MIC/MBC 125/250 μg/mL) and Aspidosperma olivaceum Muell. Arg. (MIC/MBC 250/ > 1000 μg/mL) displayed moderate antibacterial activity against Bacillus subtilis. Separation of the crude extract of Aspidosperma ramiflorum was performed according to the usual acid–base process, which produces alkaloid mixtures and closely related metabolites. The basic fraction was active against Bacillus subtilis, Staphylococcus aureus, and Escherichia coli, with MICs of 31.2, 62.5, and 250 μg/mL, respectively. The basic fractions were more active than the acid fractions, probably because they contained some active alkaloids and/or closely related metabolites absent from the other fractions, or they contained a higher concentration of these active compounds.

Piper regnellii extract biopolymer-based microparticles: production, characterization and antifungal activity

This study aims to improve characteristics of Piper regnellii extract to make it applicable in formulations to treat dermatophytosis, also known as ringworm.

Copaiba Oil and Its Constituent Copalic Acid as Chemotherapeutic Agents against Dermatophytes

Copaiba oil, an oleoresin extracted from Copaifera genus, has been widely used in popular medicine for the treatment of several diseases. The aim of this study was to investigate the antifungal activity of the copaiba oil and its isolated compounds caryophyllene oxide, copalic acid and acetoxycopalic acid against Trichophyton rubrum, Trichophyton mentagrophytes and Microsporum gypseum strains, using microdilution method and microscopy techniques. It was found that the copaiba oil and the copalic acid were active against dermatophytes by minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) tests. The MIC and MFC of copaiba oil against T. rubrum, T. mentagrophytes and M. gypseum were 125 μg mL (250 μg mL), 500 μg mL (500 μg mL) and 250 μg mL (250 μg mL), respectively. For copalic acid, the MIC and MFC were 50 μg mL (100 μg mL), 100 μg mL (100 μg mL) and 50 μg mL (100 μg mL), respectively. Fluorescence microscopy and scanning electronic microscopy were used to investigate inhibition on hyphal growth by compounds, copaiba oil and copalic acid, showing a strong inhibition and an irregular growth pattern. Cell wall, cytoplasmic membrane and intracellular contents were also damaged. In conclusion, copaiba oil and copalic acid showed great activity against dermatophytes, being potential compounds for the development of antifungal drugs.