Background: Roasted seeds of Amazonian guarana (Paullinia cupana var. sorbilis; Sapindaceae) are popular in South America due to their stimulant activity on the central nervous system (CNS). Rich in purine alkaloids, markedly caffeine, the seeds are extensively used in the Brazilian beverage industry for the preparation of soft drinks and as additives in energy drinks. Methods: To investigate the putative anti-aging and antioxidant activity of guarana, we used the model organism Caenorhabditis elegans. Chemical analyses were performed using high-performance liquid chromatography (HPLC) and electrospray ionization-mass spectrometry (ESI-MS/MS). Results: When tested in the model system Caenorhabditis elegans, the water extract from roasted guarana seeds enhanced resistance against oxidative stress, extended lifespan and attenuated aging markers such as muscle function decline and polyQ40 aggregation. Conclusions: In the current study, we demonstrate that guarana extracts can work as a powerful antioxidant in vivo; moreover, guarana extracts exhibit anti-aging properties. Our results suggest that the biological activities of guarana go beyond the extensively reported CNS stimulation.
20 December 2014 in Applied Microbiology and Biotechnology
Pseudomonas aeruginosa (PA) is an opportunistic human pathogen, which is involved in a wide range of dangerous infections. It develops alarming resistances toward antibiotic treatment. Therefore, alternative strategies, which suppress pathogenicity or synergize with antibiotic treatments are in great need to combat these infections more effectively. One promising approach is to disarm the bacteria by interfering with their quorum sensing (QS) system, which regulates the release of various virulence factors as well as biofilm formation. Herein, this work reports the rational design, optimization, and in‐depth profiling of a new class of Pseudomonas quinolone signaling receptor (PqsR) inverse agonists. The resulting frontrunner compound features a pyrimidine‐based scaffold, high in vitro and in vivo efficacy, favorable pharmacokinetics as well as clean safety pharmacology characteristics, which provide the basis for potential pulmonary as well as systemic routes of administration. An X‐ray crystal structure in complex with PqsR facilitated further structure‐guided lead optimization. The compound demonstrates potent pyocyanin suppression, synergizes with aminoglycoside antibiotic tobramycin against PA biofilms, and is active against a panel of clinical isolates from bronchiectasis patients. Importantly, this in vitro effect translated into in vivo efficacy in a neutropenic thigh infection model in mice providing a proof‐of‐principle for adjunctive treatment scenarios.
28 May 2019 in Journal of Agricultural and Food Chemistry
The dominant anthocyanins in blackcurrant are delphinidin-3-O-rutinoside and cyanidin-3-O-rutinoside. Data on their absorption and distribution in the human body are limited. Therefore, we performed a human pilot study on five healthy male volunteers consuming a blackcurrant (Ribes nigrum L.) extract. The rutinosides and their degradation products gallic acid and protocatechuic acid were determined in plasma and urine. The rutinosides’ concentrations peaked in both plasma and urine samples within 2 h of extract ingestion. The recoveries of delphinidin-3-O-rutinoside and cyanidin-3-O-rutinoside from urine samples were 0.040 ± 0.011% and 0.048 ± 0.016%, respectively, over a 48 h period. Protocatechuic acid concentration increased significantly after ingestion of the blackcurrant extract. Our results show that after ingestion of a blackcurrant extract containing delphinidin-3-O-rutinoside and cyanidin-3-O-rutinoside, significant quantities of biologically active compounds circulated in the plasma and were excreted via urine. Furthermore, these results contribute to the understanding of anthocyanin metabolism in humans.
Background: Phosphodiesterases (PDEs) play a major role in the regulation of cyclic adenosine monophosphate (cAMP)- and cyclic guanosine monophosphate (cGMP)-mediated pathways. Their inhibitors exhibit anti-inflammatory, vasodilatory and antithrombotic effects. Therefore, consumption of foods with PDE-inhibiting potential may possess beneficial influence on the risk of cardiovascular diseases. Methods: Four plant extracts (Arbutus unedo, Camellia sinensis, Cynara scolymus, Zingiber officinale) with promising ingredient profiles and physiological effects were tested for their ability to inhibit cAMP-specific PDE in vitro in a radioactive assay. Results: Strawberry tree fruit (Arbutus unedo) and tea (Camellia sinensis) extracts did not inhibit PDE markedly. Alternatively, artichoke (Cynara scolymus) extract had a significant inhibitory influence on PDE activity (IC50 = 0.9 ± 0.1 mg/mL) as well as its flavone luteolin (IC50 = 41 ± 10 μM) and 3,4-dicaffeoylquinic acid (IC50 > 1.0 mM). Additionally, the ginger (Zingiber officinale) extract and one of its constituents, [6]-gingerol, significantly inhibited PDE (IC50 = 1.7 ± 0.2 mg/mL and IC50 > 1.7 mM, respectively). Crude fractionation of ginger extract showed that substances responsible for PDE inhibition were in the lipoid fraction (IC50 = 455 ± 19 μg/mL). Conclusions: A PDE-inhibitory effect was shown for artichoke and ginger extract. Whether PDE inhibition in vivo can be achieved through ingestion of artichoke or ginger extracts leading to physiological effects concerning cardiovascular health should be addressed in future research.