Therapy with antimicrobial drugs, such as clindamycin, that perturb the intestinal flora but fail to inhibit growth of other microorganisms can permit the proliferation of Clostridium difficile and the elaboration of exotoxin. Therefore, there has been increasing interest in the use of inhibitors of antibiotic resistance for use in combination therapy. The essential oil of Cinnamomum zeylanicum bark enhanced the bactericidal activity of clindamycin and decreased the minimum inhibitory concentration of clindamycin required for a toxicogenic strain of C. difficile. Thin-layer chromatography (TLC) analysis of the essential oil separated a fraction (R(f) = 0.54) that was the most effective at enhancing the clindamycin antimicrobial activity. Using gas liquid chromatography and known standards, the active fraction was identified as trans-cinnamaldehyde (3-phenyl-2-Propenal). Combinations of clindamycin and trans-cinnamaldehyde were tested to determine the fractional inhibitory concentration (FIC) index by conventional checkerboard titration. The FIC index for C. difficile was found to be 0.312, which confirmed the synergistic actions of clindamycin and trans-cinnamaldehyde. The presence of 20 microg/mL of trans-cinnamaldehyde decreased the MIC of clindamycin for C. difficile 16-fold, from 4.0 to 0.25 microg/mL. These results signify that low concentrations of trans-cinnamaldehyde elevate the antimicrobial action of clindamycin, suggesting a possible clinical benefit for utilizing these natural products for combination therapy against C. difficile.

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The potential applications of Fe 3 O 4 magnetite nanoparticles (MNPs) in nanomedicine as drug delivery systems are well known. In this study we prepared umbelliprenin-coated Fe 3 O 4 MNPs and evaluated the antiproliferative effect of combination in vitro. After synthesis of Fe 3 O 4 MNPs, particles were characterized by transmission electron microscopy, energy-dispersive spectroscopy, and X-ray diffraction spectroscopy techniques. The natural candidate compoundumbelliprenin-was isolated and identified and umbelliprenin-coated Fe 3 O 4 MNPs were prepared, using precipitation method. The surface chemistry of umbelliprenin-coated Fe 3 O 4 MNPs as well as their thermal decomposition characteristics was examined using Fourier transform infrared spectroscopy and Thermogravimetric Analyzer equipment, respectively. HT-1080 cells were cultured until the logarithmic phase of growth, and MTT assay was successfully carried out to evaluate the possible cytotoxic effects of umbelliprenin-coated Fe 3 O 4 MNPs in viable cells in vitro. The results demonstrated that umbelliprenin has moderate antiproliferative effects with IC 50 value of 50 µg/mL. However, the combination of umbelliprenin and Fe 3 O 4 MNPs showed the IC 50 value of 9 µg/mL. In other words, cell proliferation decreased to the remarkably-low proportion of 45% after treating cells with umbelliprenin-coated Fe 3 O 4 MNPs. This suggests that with the aid of nanoparticles as carriers, natural products may have even broader range of medical applications in future.

Tellurium (Te) is a semimetal rare element in nature. Together with oxygen, sulfur (S), and selenium (Se), Te is considered a member of chalcogen group. Over recent decades, Te applications continued to emerge in different fields including metallurgy, glass industry, electronics, and applied chemical industries. Along these lines, Te has recently attracted research attention in various fields. Though Te exists in biologic organisms such as microbes, yeast, and human body, its importance and role and some of its potential implications have long been ignored. Some promising applications of Te using its inorganic and organic derivatives including novel Te nanostructures are being introduced. Before discovery and straightforward availability of antibiotics, Te had considered and had been used as an antibacterial element. Antilishmaniasis, antiinflammatory, antiatherosclerotic, and immuno-modulating properties of Te have been described for many years, while the innovative applications of Te have started to emerge along with nanotechnological advances over the recent years. Te quantum dots (QDs) and related nanostructures have proposed novel applications in the biological detection systems such as biosensors. In addition, Te nanostructures are used in labeling, imaging, and targeted drug delivery systems and are tested for antibacterial or antifungal properties. In addition, Te nanoparticles show novel lipid-lowering, antioxidant, and free radical scavenging properties. This review presents an overview on the novel forms of Te, their potential applications, as well as related toxicity profiles.

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In this investigation, the antifungal activities of chloroform and water extracts of Ferula persica. var. persica. Willd. roots were studied using conventional disk diffusion method. The chloroform extract showed antifungal activity at concentrations tested. Bioassay-guided fractionation study of the chloroform extract by preparative thin-layer chromatography (PTLC) detected two antifungal fractions that were effective against some fungi. Using conventional spectroscopy methods, the active fractions were identified as t-butyl 3-[(1-methylpropyl)dithio]-2-propenyl malonate (persicasulfide A) (1) and t.-butyl 3-[(1-methylthiopropyl)dithio]-2-propenyl malonate (persicasulfide B) (2), recently isolated from Ferula persica. var. latisecta.. These compounds showed the most potent antifungal activity with MICs of ≤ 62.5 µg/ml against filamentous fungi.

The enhancement of the antibacterial activity of ampicillin by different extracts of Berberis integerrima fruits was evaluated against Staphylococcus aureus. Disk diffusion and agar dilution methods were used to determine the antibacterial activity of ampicillin in the absence and presence of different plant extracts or various fractions eluted by column chromatography. A clinical isolate of S. aureus was used as a test strain. The active component of B. integerrima fruits involved in the enhancement of ampicillin activity was purified and identified as 1-methyl malate using different spectroscopic methods. Both the ethanol extract of B. integerrima fruits and 1-methyl malate enhanced the antibacterial activity of ampicillin. The total extract as well as 1-methyl malate increased the antibacterial activity of ampicillin against the test strain. The potency of ampicillin against the test strain was increased 64-fold when tested with a sub-toxic concentration of total extract of B. integerrima fruits. Also, 1-methyl malate increased the bactericidal activity of ampicillin. In the presence of 2 mg/mL of 1-methyl malate the MIC of ampicillin for S. aureus decreased from 128 to 1 microg/mL (128-fold).

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