Antibacterial and antioxidant activity of cinnamon essential oil-laden 45S5 bioactive glass/soy protein composite scaffolds for the treatment of bone infections and oxidative stress.

This study aimed to fabricate cinnamon essential oil (CO)-laden 45S5 bioactive glass (BG)/soy protein (SP) scaffolds exhibiting antioxidant and antibacterial activity. In this regard, 45S5 BG-based scaffolds were produced by the foam replica method, and subsequently the scaffolds were coated with various concentrations of CO (2.5, 5 and 7 (v/v) %) incorporated SP solution. Scanning electron microscopy images revealed that the CO-laden SP effectively attached to the 45S5 BG scaffold struts. The presence of 45S5 BG, SP and CO was confirmed using Fourier transform infrared spectroscopy. Compressive strength results indicated that SP based coatings improved the scaffolds' mechanical properties compared to uncoated BG scaffolds. The loading efficiency and releasing behaviour of the different CO concentrations were tested by gas chromatography-mass spectroscopy and UV-Vis spectroscopy. The results showed that CO incorporated scaffolds have controlled releasing behaviour over seven days. Furthermore, the coating on the scaffold surfaces slightly retarded, but it did not inhibit, the in vitro bioactivity of the scaffolds. Moreover, the antioxidant and antibacterial activity of CO was studied. The free radical scavenging activity measured by DPPH was 5 ± 1, 41 ± 3, 44 ± 1 and 43 ± 1 % for BGSP, CO2.5, CO5 and CO7, respectively. The antioxidant activity was thus enhanced by incorporating CO. Agar diffusion and colony counting results indicated that the incorporation of CO increased the antibacterial activity of scaffolds against S. aureus and E. coli. In addition, cytotoxicity of the scaffolds was investigated using MG-63 osteoblast-like cells. The results showed that the BG-SP scaffold was non-toxic under the investigated conditions, whereas dose-dependent toxicity was observed in CO-laden scaffolds. Considered together, the developed phytotherapeutic agent laden 45S5 BG-based scaffolds are promising for bone tissue engineering exhibiting capability to combat bone infections and to protect against oxidative stress damage.

Sesquiterpenes and sesquiterpenoids harbor modulatory allosteric potential and affect inhibitory GABAA receptor function in vitro.

Naturally occurring compounds such as sesquiterpenes and sesquiterpenoids (SQTs) have been shown to modulate GABAA receptors (GABAA Rs). In this study, the modulatory potential of 11 SQTs at GABAA Rs was analyzed to characterize their potential neurotropic activity. Transfected HEK293 cells and primary hippocampal neurons were functionally investigated using electrophysiological whole-cell recordings. Significantly different effects of ß-caryophyllene and α-humulene, as well as their respective derivatives ß-caryolanol and humulol, were observed in the HEK293 cell system. In neurons, the concomitant presence of phasic and tonic GABAA R configurations accounts for differences in receptor modulation by SQTs. The in vivo presence of the γ2 and δ subunits is important for SQT modulation. While phasic GABAA receptors in hippocampal neurons exhibited significantly altered GABA-evoked current amplitudes in the presence of humulol and guaiol, negative allosteric potential at recombinantly expressed α1 ß2 γ2 receptors was only verified for humolol. Modeling and docking studies provided support for the binding of SQTs to the neurosteroid-binding site of the GABAA R localized between transmembrane segments 1 and 3 at the (+ α)-(- α) interface. In sum, differences in the modulation of GABAA R isoforms between SQTs were identified. Another finding is that our results provide an indication that nutritional digestion affects the neurotropic potential of natural compounds.

Isolation of sesquiterpenoids from Matricaria chamomilla by means of solvent assisted flavor evaporation and centrifugal partition chromatography.

The (semi)volatile fraction of Matricaria chamomilla L., an annual herbal plant from the family of Asteraceae, contains high quantities of sesquiterpenes and sesquiterpenoids. A method was developed to achieve isolation and separation of these compounds, using a combination of solvent assisted flavor evaporation (SAFE) and solid support-free liquid-liquid chromatography. The biphasic liquid solvent system n-heptane/ethyl acetate/methanol/water, 5/2/5/2 v/v/v/v (Arizona S) was elaborated as a suitable solvent system for the simultaneous separation of the target compounds. The lab-scale liquid-liquid chromatography separation performed in a countercurrent chromatography (CCC) column was successfully transferred to a semi-preparative centrifugal partition chromatography (CPC) column, which enabled the isolation of artemisia ketone, artemisia alcohol, α-bisabolone oxide A, and (E)-en-yn-dicycloether. α-Bisabolol oxide A and (Z)-en-yn-dicycloether co-eluted, but were successfully separated by subsequent size-exclusion chromatography (SEC). Similarly, spathulenol and α-bisabolol oxide B were obtained as a mixture, and were separated by means of column chromatography using silica gel as stationary phase. The isolated compounds were characterized by means of nuclear magnetic resonance spectroscopy (NMR) and gas chromatography-mass spectrometry (GC-MS).

Quantification of volatile metabolites derived from garlic in human breast milk.

Maternal garlic intake during pregnancy and the breastfeeding period has been reported to be associated with the potential of modulating later garlic acceptance in infants. However, the metabolism of garlic constituents in humans and their elimination and potential excretion into human milk are not yet fully understood. In previous studies, we identified volatile garlic-derived metabolites in human milk as well as in human urine, namely allyl methyl sulfide, allyl methyl sulfoxide and allyl methyl sulfone. To monitor the excretion of these garlic metabolites in a larger cohort, we quantified these metabolites in a total of 18 human milk sets, whereby each set comprised of one sample collected before and three samples after garlic consumption. The analyses revealed that the concentrations of the metabolites were most abundant 1-3.5 h after garlic consumption, with distinct differences between test persons regarding metabolite concentrations as well as temporal excretion.

Identification and quantification of glue-like off-odors in elastic therapeutic tapes.

Elastic therapeutic tapes are an important tool in the field of physical therapy and medicine. These tapes contain types of adhesive. However, sensory evaluations revealed the release of pronounced and irritating odors of the tapes. Negative odors were, amongst others, reported in elastic therapeutic tapes containing acrylic adhesives. In this study, the odor of four different tape samples was evaluated applying a descriptive analysis approach carried out by a trained sensory panel. Afterwards, the volatile compounds were recovered from the samples by solvent extraction and isolated by solvent-assisted flavor evaporation (SAFE). The obtained distillates were subsequently analyzed by gas chromatography-olfactometry (GC-O) and two-dimensional GC-O coupled with mass spectrometry (2D-GC-MS/O). To determine the most potent odorants in the distillates, odor extract dilution analyses (OEDA) were carried out. Thirty-one odorants were successfully identified using this approach, which were all described for the first time as odorants in tapes. Amongst the set of volatiles, unsaturated and saturated aldehydes were present, eliciting fatty, soapy, and citrus-like odor impressions, as well as a range of glue-like, moldy, and fruity smelling odor-active volatiles, such as 2-ethyl-1-hexanol, butyl benzoate, and 3-phenyltoluene. Based on their relative intensities, the concentrations of the glue-like smelling substances were determined: 2-ethyl-1-hexanol, present in all samples, was determined with concentrations ranging from 10 to 200 mg/kg in the investigated tapes.

Are odorant constituents of herbal tea transferred into human milk?

The present study investigates aroma transfer from commercial nursing tea, consumed in the maternal diet, into human milk by correlating sensory assessments with quantitative analytical data. The target terpenes were quantified in milk (expressed before and after tea consumption) and tea samples via gas chromatography­mass spectrometry (GC-MS) using stable isotope dilution assays (volunteer donors n = 5). Sensory analyses were carried out on different milk samples from a single donor, sampled before (blank) and at different times after tea ingestion. Quantitative analysis revealed that no significant odorant transfer into milk was observed after lactating women drank the tea. The comparative sensorial analysis of milk samples expressed before and after tea consumption confirmed that tea ingestion had no significant influence on the odor profile of human milk.

GABA(A) receptor modulation by terpenoids from Sideritis extracts.

SCOPE: GABAA receptors are modulated by Sideritis extracts. The aim of this study was to identify single substances from Sideritis extracts responsible for GABAA receptor modulation. METHODS AND RESULTS: Single volatile substances identified by GC have been tested in two expression systems, Xenopus oocytes and human embryonic kidney cells. Some of these substances, especially carvacrol, were highly potent on GABAA receptors composed of α1ß2 and α1ß2γ2 subunits. All effects measured were independent from the presence of the γ2 subunit. As Sideritis extracts contain a high amount of terpenes, 13 terpenes with similar structure elements were tested in the same way. Following a prescreening on α1ß2 GABAA receptors, a high-throughput method was used for identification of the most effective terpenoid substances on GABA-affinity of α1ß2γ2 receptors expressed in transfected cell lines. Isopulegol, pinocarveol, verbenol, and myrtenol were the most potent modifiers of GABAA receptor function. CONCLUSION: Comparing the chemical structures, the action of terpenes on GABAA receptors is most probably due to the presence of hydroxyl groups and a bicyclic character of the substances tested. We propose an allosteric modulation independent from the γ2 subunit and similar to the action of alcohols and anesthetics.

Monitoring of biotransformation of hop aroma compounds in an in vitro digestion model.

An in vitro digestion procedure followed by gas chromatography-mass spectrometry analysis has been applied to assess the stability of aroma compounds from hop oil in the human gastrointestinal tract. Hop oil is used in phytotherapy as a sedative, yet the bioactive substances responsible for this effect have not been conclusively clarified. Therefore, the focus of this study was placed on hop aroma substances that: (i) have been previously described to possess sedative properties, (ii) are suspected to have these properties due to structural features, or (iii) that are present in hop oil in high concentrations. While some compounds remained unchanged under the simulated physiological conditions, others underwent transformations to a great extent. Particularly interesting was the formation of α-terpineol and linalool from several different aroma compounds. α-Terpineol has been previously described as a bioactive compound with anti-inflammatory properties. Linalool is a well-known sedative compound and its formation during digestion could enhance the sedative effect of hop oil. The results of this study show that gastrointestinal processes can modulate the chemical composition of ingested aroma constituents and might even influence the bioactivity of essential oils.

Comparative human-sensory evaluation and quantitative comparison of odour-active oxidation markers of encapsulated fish oil products used for supplementation during pregnancy and the breastfeeding period.

Three different commercial encapsulated fish oil supplements were evaluated by orthonasal sensory evaluation of the encapsulated oil samples, and were rated according to characteristic odour qualities and hedonic impact. The potent odourants of the fish oil samples were obtained by solvent extraction followed by high vacuum transfer of the volatiles, and were evaluated by means of high resolution gas chromatography-olfactometry (HRGC-O). Comparative aroma extract dilution analysis of the solvent extract samples revealed 40 odourants. Most of these were identified based on their respective retention indices on two capillaries of different polarities, their mass spectral data, as well as their odour characteristics during HRGC-O, in comparison with the respective reference compounds. Thereby (poly)unsaturated fatty acid oxidation products were demonstrated to play a significant role in the volatile fraction of the fish oil supplements. Quantification of selected oxidation marker substances confirmed predominant presence of these compounds in the investigated samples, but also major quantitative differences between samples with regard to specific compounds. These data may be used as the basis for future evaluation of sensory quality of encapsulated fish oil supplements, and might relate to the degree of acceptance or rejection by the mothers being supplemented with the respective products.