Characterization of Sunflower Oil Extracts from the Lichen Usnea barbata.

Shereen Basiouni,Reda Tarabees,Awad A Shehata,Mohamed El-Sayed,Wolfgang Eisenreich,Marwa A A Fayed,Thomas Geisberger,Manfred Hessel,Ahmed Elkhatam,Claudia Huber,Klaus-Rainer Töllner

doi:10.3390/metabo10090353

Shereen Basiouni, Reda Tarabees + Show 9 more

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https://doi.org/10.3390/metabo10090353

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Abstract

The increasing global emergence of multidrug resistant (MDR) pathogens is categorized as one of the most important health problems. Therefore, the discovery of novel antimicrobials is of the utmost importance. Lichens provide a rich source of natural products including unique polyketides and polyphenols. Many of them display pharmaceutical benefits. The aim of this study was directed towards the characterization of sunflower oil extracts from the fruticose lichen, Usnea barbata. The concentration of the major polyketide, usnic acid, was 1.6 mg/mL extract as determined by NMR analysis of the crude mixture corresponding to 80 mg per g of the dried lichen. The total phenolics and flavonoids were determined by photometric assays as 4.4 mg/mL (gallic acid equivalent) and 0.27 mg/mL (rutin equivalent) corresponding to 220 mg/g and 13.7 mg/g lichen, respectively. Gram-positive (e.g., Enterococcus faecalis) and Gram-negative bacteria, as well as clinical isolates of infected chickens were sensitive against these extracts as determined by agar diffusion tests. Most of these activities increased in the presence of zinc salts. The data suggest the potential usage of U. barbata extracts as natural additives and mild antibiotics in animal husbandry, especially against enterococcosis in poultry.

Highlights

The emergence of multidrug resistant (MDR) pathogenic bacteria poses a worsening and general health problem [1]
Results of usnic acid (UA) were unequivocally assigned by two-dimensional NMR experiments, as reported earlier [48]
The the internal reference, dimethyl fumarate (DMFum), which was added to the NMR sample at 2D)

Summary

Introduction

The emergence of multidrug resistant (MDR) pathogenic bacteria poses a worsening and general health problem [1]. This phenomenon was mainly caused by excessive use of antimicrobials as therapeutics and preventive tools in the animal industry and large-scale poultry operations. This challenge has led to a constant search for the most suitable alternatives for in-feed antimicrobials [2,3]. The WHO has recently rated the phenomenon of MDR among the most important problems threatening human health, as there are large gaps in the existing surveillance of antimicrobial resistance in many parts of the world [4]. A steadily increasing level of MDR bacteria has been reported, for example of Escherichia coli [11], Campylobacter [12,13,14], Salmonella [15,16], and methicillin-resistant

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