Release Of Phytochemicals Research Articles

Assessment of physicochemical properties, dissolution kinetics and storage stability of a novel strawberry confection designed for delivery of chemopreventive agents

Abstract Oral diseases are a common health concern within the United States, and have been associated with increased risk of certain chronic disease and reduced overall quality of life. A unique starch-based confection containing freeze-dried strawberries was developed for sustained, targeted phytochemical release to the oral mucosa for use in future chemoprevention trials. Sensory evaluation was used to optimize the confectionery formulation for this investigation. Physicochemical properties, scanning electron microscopy and dissolution studies revealed the effects of 14-day storage on phytochemical release from the amorphous semisolid matrix. Upon storage, moisture content decreased 4% and water was more tightly bound. Rheological testing revealed Newtonian-like response to shear below 10 s−1 and pseudoplastic behavior at higher shear. Changes in the food structure were observed with scanning electron microscopy. Total phenolics released in phosphate buffer (47.2 ± 2.7 mg GAE/L) or simulated saliva (66.7 ± 1.2 mg GAE/L) after 10 h from fresh confections was significantly (p = 0.001) greater compared to stored confections in phosphate buffer (39.0 ± 2.9 mg GAE/L) and simulated saliva (56.4 ± 1.0 mg GAE/L). Strawberry confections may be a novel strategy for localized delivery and sustained release of strawberry bioactive compounds.

Influence of in vitro invasion of arbuscular mycorrhizae on general characteristics and phytochemical concentration of plants: A review

This review is an attempt to study the use of VAM in the release of phytochemicals from medicinally important plants. To popularize the efficacy of the natural resources as Arbuscular Mycorrhizae (AMF) – a nutrient source of soil which manages the soil fertility naturally as well as its contribution in the reduction of additional fertilizers which are used for further betterment of plant crops and soil, this article covers almost a full range of the properties of AM with its science and mechanisms in general as well as the changes in the concentration and properties of the phytochemicals from medicinal plants.

Application of Natural Blends of Phytochemicals Derived from the Root Exudates of Arabidopsis to the Soil Reveal That Phenolic-related Compounds Predominantly Modulate the Soil Microbiome

The roots of plants have the ability to influence its surrounding microbiology, the so-called rhizosphere microbiome, through the creation of specific chemical niches in the soil mediated by the release of phytochemicals. Here we report how these phytochemicals could modulate the microbial composition of a soil in the absence of the plant. For this purpose, root exudates of Arabidopsis were collected and fractionated to obtain natural blends of phytochemicals at various relative concentrations that were characterized by GC-MS and applied repeatedly to a soil. Soil bacterial changes were monitored by amplifying and pyrosequencing the 16 S ribosomal small subunit region. Our analyses reveal that one phytochemical can culture different operational taxonomic units (OTUs), mixtures of phytochemicals synergistically culture groups of OTUs, and the same phytochemical can act as a stimulator or deterrent to different groups of OTUs. Furthermore, phenolic-related compounds showed positive correlation with a higher number of unique OTUs compared with other groups of compounds (i.e. sugars, sugar alcohols, and amino acids). For instance, salicylic acid showed positive correlations with species of Corynebacterineae, Pseudonocardineae and Streptomycineae, and GABA correlated with species of Sphingomonas, Methylobacterium, Frankineae, Variovorax, Micromonosporineae, and Skermanella. These results imply that phenolic compounds act as specific substrates or signaling molecules for a large group of microbial species in the soil.

Optimisation of lactic acid fermentation of York cabbage for the development of potential probiotic products

SummaryIn this study, York cabbage was used as the sole substrate for the lactic acid (LA) fermentation with Lactobacillus plantarum. York cabbage was blanched at 95 °C for 12 min to inactivate surface microflora prior to fermentation. To achieve an optimal fermentation condition that would result in higher release of phytochemicals and antioxidant (AO) capacity in the broth, Box‐Behnken design integrating a desirability approach was used. A second‐order polynomial equation was developed, indicating the effect of solute/liquid ratio, agitation rate and fermentation time on desired parameters. The optimised factors were used for fermenting York cabbage to obtain maximum bacterial growth, LA, polyphenols and AO capacity. There was ≈5 log cfu mL−1 increment in bacterial growth after fermentation, whereas LA production reached up to 4.97 mg mL−1. Results showed that fermentation retains 95–98% and 90–95% of TPC and AO capacity, respectively. During refrigerated storage (4 °C), the cell numbers, bioactive components and acidity were maintained till 15‐day storage.

Assessing the potential for rhizoremediation of PCB contaminated soils in northern regions using native tree species

Rhizosphere bioremediation of polychlorinated biphenyls (PCBs) offers a potentially inexpensive approach to remediating contaminated soils that is particularly attractive in remote regions including the Arctic. We assessed the abilities of two tree species native to Alaska, Salix alaxensis (felt-leaf willow) and Picea glauca (white spruce), to promote microbial biodegradation of PCBs via the release of phytochemicals upon fine root death. Crushed fine roots, biphenyl (PCB analogue) or salicylate (willow secondary compound) were added to microcosms containing soil spiked with PCBs and resultant PCB disappearance, soil toxicity and microbial community changes were examined. After 180 d, soil treated with willow root crushates showed a significantly greater PCB loss than untreated soils for some PCB congeners, including the toxic congeners, PCB 77, 105 and 169, and showed a similar PCB loss pattern (in both extent of degradation and congeners degraded) to biphenyl-treated microcosms. Neither P. glauca (white spruce) roots nor salicylate enhanced PCB loss, indicating that biostimulation is plant species specific and was not mediated by salicylate. Soil toxicity assessed using the Microtox bioassay indicated that the willow treatment resulted in a less toxic soil environment. Molecular microbial community analyses indicated that biphenyl and salicylate promoted shifts in microbial community structure and composition that differed distinctly from each other and from the crushed root treatments. The biphenyl utilizing bacterium, Cupriavidus spp. was isolated from the soil. The findings suggest that S. alaxensis may be an effective plant for rhizoremediation by altering microbial community structure, enhancing the loss of some PCB congeners and reducing the toxicity of the soil environment.

Abstract 5673: Controlled-release systemic delivery of chemopreventive agents - An update

Abstract Controlled release systemic delivery of chemopreventive agents bypasses all the hurdles of oral delivery, including issues with absorption, liver first-pass effect and fast clearance by kidneys. We had previously demonstrated the effectiveness of controlled release of chemopreventive agents by systemic route using subcutaneous implants of polycaprolactone (PCL):F68 (9:1). This implant concept reduced the effective dose by two-orders of magnitude and increased bioavailability. However, there were several issues that required further optimization. Specifically, i) the rate of release of lipophilic compounds such as curcumin was not high enough to achieve biologically-effective dose; ii) the implant formulation gave an undesirable burst release, followed by a more sustained release; and iii) lack of correlation between in vitro and in vivo release. Different drugs require varying release kinetics in order to achieve biologically-effective dose. To achieve this, the formulation of the polymer matrix was modified by replacing the water-soluble polymer F68 with polyethylene glycol (PEG; Mol. Wt. 8,000). By varying the composition of the two polymers, a ratio of PCL:PEG of 65:35 increased the initial release by nearly 4-fold and an average 2-fold increase in daily release was achieved at the end of one month. Thus, adding eight to ten coatings of a 10% PCL solution prevented the immediate release of the surface-bound drug and essentially abolished the burst release phenomenon. These modifications in the implant formulation with curcumin have resulted in near zero-order kinetics over one month tested. Finally, we previously reported the short-term release of phytochemicals from subcutaneous implants in a rat model. We have now measured the release up to 16 months and found that the polymeric implants are still continuing to release the compounds. After 10 and 16 months, respectively punicalagin showed a release of 20.8 and 8.2 µg/day, curcumin 28 and 18.5 µg/day and green tea polyphenols 42 and 4.7 µg/day. We also observed a tissue depot of test agent at the site of implant that seems to contribute to the release of the drug systemically. This tissue depot may facilitate the release kinetics to be of zero-order. Based on our standardized ‘sink’ conditions, curcumin released on an average 3.6 ± 0.14 fold higher amounts in vivo than in vitro, when tested at various time intervals. Thus, our controlled-release, systemic-delivery system circumvents major limitations of oral delivery, provides continuous (“24/7”) delivery of drug for long duration, lowers the total amount of drug required, enables delivery of biologically-effective dose at the target site. This essentially allows testing of several minor phytochemicals and synthetic structural analogs that may remain uninvestigated in animal models due to insufficient quantities (Supported from the USPHS grants CA-118114 and CA-125152 and Agnes Brown Duggan Endowment). Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5673.

Removing the mustard oil bomb from seeds: transgenic ablation of myrosin cells in oilseed rape (Brassica napus) produces MINELESS seeds.

Many plant phytochemicals constitute binary enzyme–glucoside systems and function in plant defence. In brassicas, the enzyme myrosinase is confined to specific myrosin cells that separate the enzyme from its substrate; the glucosinolates. The myrosinase-catalysed release of toxic and bioactive compounds such as isothiocyanates, upon activation or tissue damage, has been termed ‘the mustard oil bomb’ and characterized as a ‘toxic mine’ in plant defence. The removal of myrosin cells and the enzyme that triggers the release of phytochemicals have been investigated by genetically modifying Brassica napus plants to remove myrosinase-storing idioblasts. A construct with the seed myrosin cell-specific Myr1.Bn1 promoter was used to express a ribonuclease, barnase. Transgenic plants ectopically expressing barnase were embryo lethal. Co-expressing barnase under the control of the Myr1.Bn1 promoter with the barnase inhibitor, barstar, under the control of the cauliflower mosaic virus 35S promoter enabled a selective and controlled death of myrosin cells without affecting plant viability. Ablation of myrosin cells was confirmed with light and electron microscopy, with immunohistological analysis and immunogold-electron microscopy analysis showing empty holes where myrosin cells normally are localized. Further evidence for a successful myrosin cell ablation comes from immunoblots showing absence of myrosinase and negligible myrosinase activity, and autolysis experiments showing negligible production of glucosinolate hydrolysis products. The plants where the myrosin defence cells have been ablated and named ‘MINELESS plants’. The epithiospecifier protein profile and glucosinolate levels were changed in MINELESS plants, pointing to localization of myrosinases and a 35 kDa epithiospecifier protein in myrosin cells and a reduced turnover of glucosinolates in MINELESS plants.

Almond skins digestion: release of phytochemicals and gut health.

Almond skins (Amygdalus communis L.) contain high‐value components, such as dietary fibre and polyphenols. Here we describe the bioaccessibility of phytochemicals from almond skins during gastrointestinal (GI) digestion and the role of cell walls in regulating bioaccessibility. A dynamic gastric model of digestion which simulates the physical‐chemical processing of the stomach and accurately mimics both the transit time and the luminal content of the upper human gut was used to digest almond skins in vitro. No significant changes were observed in the sugar composition of the cell walls of almond skin after in vitro gastric or in vitro gastric + duodenal digestion, suggesting that no degradation of the dietary fibre had occurred. The decrease in the concentration of the major phenolics and flavonoids within the almond skins after digestion was used as a measure of their bioaccessibility in the GI tract. Under UV light, blue autofluorescence was emitted from the phenolics within the walls of the sclerenchyma cells, the lignified cells of the xylem, and from the cuticle overlying the nucellar layer. Phytochemicals from almond skins are bioavailable in the GI tract. The high dietary fibre content could be exploited for the potential health benefits of non‐glycaemic carbohydrate functional food preparations, mainly for gut health.This work has been funded by the Almond Board of California.

ChemInform Abstract: Insects Feeding on Plants: Rapid Signals and Responses Preceding the Induction of Phytochemical Release

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Altered Profile of Secondary Metabolites in the Root Exudates of Arabidopsis ATP-Binding Cassette Transporter Mutants

Following recent indirect evidence suggesting a role for ATP-binding cassette (ABC) transporters in root exudation of phytochemicals, we identified 25 ABC transporter genes highly expressed in the root cells most likely to be involved in secretion processes. Of these 25 genes, we also selected six full-length ABC transporters and a half-size transporter for in-depth molecular and biochemical analyses. We compared the exuded root phytochemical profiles of these seven ABC transporter mutants to those of the wild type. There were three nonpolar phytochemicals missing in various ABC transporter mutants compared to the wild type when the samples were analyzed by high-performance liquid chromatography-mass spectrometry. These data suggest that more than one ABC transporter can be involved in the secretion of a given phytochemical and that a transporter can be involved in the secretion of more than one secondary metabolite. The primary and secondary metabolites present in the root exudates of the mutants were also analyzed by gas chromatography-mass spectrometry, which allowed for the identification of groups of compounds differentially found in some of the mutants compared to the wild type. For instance, the mutant Atpdr6 secreted a lower level of organic acids and Atmrp2 secreted a higher level of amino acids as compared to the wild type. We conclude that the release of phytochemicals by roots is partially controlled by ABC transporters.