benzofurans and baicalein

Biofilms are often the cause of chronic human infections and contaminate industrial or medical equipment. The traditional approach has been to use increasing concentrations of antibiotics, but microorganisms rapidly develop multiresistance to them. Therefore, we investigated the use of natural substances as an alternative solution. The quantification of the biofilms based on the colonized areas was measured using a Cellavista automatic microscope equipped with image analysis software. Using the Cellavista device brings new possibilities for qualification and quantification of sessile cells. In our study, this feature was documented by exploring the antifungal/anti-biofilm activity of amphotericin B, baicalein, chitosan and usnic acid against yeast biofilm formation. The influence of these substances on the formation and eradication of opportunistic pathogenic yeasts Candida parapsilosis and Candida krusei biofilms was studied in 96-well polystyrene microtiter plates. While amphotericin B was not very efficient, the use of baicalein and chitosan, even in minimum inhibitory concentrations, was found to rapidly decrease the colonized areas in the wells. The usnic acid did not display any significant antibiofilm properties even at concentration 300μgml(-1). Our results propose that Cellavista is a promising tool for the study of yeast biofilm formation and the effects of antimicrobial agents.

Topics: Amphotericin B; Anti-Infective Agents; Benzofurans; Biofilms; Candida; Chitosan; Flavanones; Humans; Image Processing, Computer-Assisted; Microbial Sensitivity Tests; Microscopy

The root and stem of Vitis amurensis (Vitaceae) have popularly used as traditional medicine for treatment of cancer and various pains in Korea and Japan. Recent studies, its root and stem possess anti-inflammatory, anti-tumor activities, and protective effects against beta-amyloid-induced oxidative stress.. This study deals with the isolation, structural identification of the potent bioactive compounds from the leaf and stem, and their antioxidant capacity, as well as anti-inflammatory effect via lipoxygenase inhibitory assay.. All isolated compounds yielded after using column chromatography were identified base on the physico-chemical properties and 1D, 2D NMR spectra. The scavenge ability against DPPH and ABTS(+) radicals, and to inhibit lipid peroxidation, as well as lipoxygenase type I inhibitory activity of all isolates were performed using in vitro assays.. Eleven resveratrol derivatives (1-11), including a new oligostilbene cis-amurensin B (9), whose structures were determined on the basis of extensively spectral analyses, were isolated from the leaf and stem of Vitis amurensis. The isolates (1-11) were examined for their antioxidant activities by evaluating scavenge ability against DPPH and ABTS(+) radicals, and to inhibit lipid peroxidation. Stilbenes 1 and 4, and oligostilbenes 5-10 displayed moderate anti-lipid peroxidation activities, but all the isolates exhibited strong ABTS(+) radical scavenging activity in the dose-dependent manner. In addition, the isolates showed stronger inhibitory capacity against soybean lipoxygenase type I than that of baicalein, a positive control. Of the isolates, r-2-viniferin (8) exhibited the strongest scavenging activity against ABTS(+) radical with TEAC value of 5.57, and the most potential inhibitory effect on soybean lipoxygenase with the IC(50) value of 6.39 microM.. This is the first report on the potential antioxidant and LOX-1 inhibitory effects of oligostilbenes isolated from the leaf and stem of Vitis amurensis. In addition, chemical compositions isolated from the leaf and stem are almost similar to those isolated from the root of Vitis amurensis. Therefore, the results may explain, in part, the uses of the leaf and stem, as well as the root of Vitis amurensis in the Korean traditional medicine.

Topics: Antioxidants; Benzofurans; Flavanones; Lipid Peroxidation; Lipoxygenase; Lipoxygenase Inhibitors; Plant Extracts; Plant Leaves; Plant Stems; Resveratrol; Stilbenes; Vitis