Dodecyl Gallate Research Articles

Contact sensitization to cosmetic series of allergens in patients with rosacea: A prospective controlled study.

Previous studies have documented the cosmetic allergic contact dermatitis due to common cosmetic allergens in standard series and various cosmetic products used in rosacea patients; however, the prevalence of contact sensitization to other cosmetic allergens other than those in standard series is largely unknown. To assess the prevalence of contact sensitization to a European cosmetic series of allergens (Chemotechnique Diagnostics AB, Malmö, Sweden) in rosacea patients and to compare this with the prevalence observed in general population. In this prospective monocenter study, 103 patients with rosacea and 104 control subjects were investigated for contact sensitizations via patch testing the cosmetic series including 49 allergens. At least one positive allergic reaction was observed in 62 (60.2%) rosacea patients, and in 25 (24.0%) control subjects. Compared with control subjects, rosacea patients were statistically more likely to have positive patch tests. The most common allergens giving positive results were octyl gallate (10.68%), dodecyl gallate (8.74%), tert-Butylhydroquinone (7.77%), thimerosal (6.80%), euxyl K400 (6.80%), cocamidopropyl betaine (5.83%), and 2,6-Di-tert-butyl-4-cresol (4.85%). This study shows that rosacea patients show a strikingly high prevalence of contact sensitization to cosmetic allergens. We recommend the additional use of cosmetic series for patch testing, and the careful use of cosmetics in rosacea patients if cosmetic contact sensitivity is suspected.

Combined application of gallate ester and α-tocopherol in oil-in-water emulsion: Their distribution and antioxidant efficiency

Gallic acid or its alkyl ester was added in combination with α-tocopherol in the oil-in-water (O/W) emulsion to investigate their interaction in emulsions. Results showed that all the tested gallate esters (propyl, octyl and dodecyl gallate) showed synergistic antioxidant activities with α-tocopherol, and propyl gallate with the shortest alkyl chain length possessed the highest synergistic ability. The interaction efficiency was consistent with the order of their apparent static quenching constants obtained from fluorescence quenching studies. This suggested that the antioxidant synergy could be due to their molecular interactions. With further confirmation by antioxidant decomposition studies, the mechanism for such antioxidant synergy in O/W emulsions was proposed to begin with the initial quick oxidation of α-tocopherol into α-tocopherol quinine, resulting in its oriented exposure to the interfacial membrane of O/W emulsion and, subsequently, being reduced by propyl gallate esters in the interfacial layer to regenerate α-tocopherol.

894 Comprehensive patch testing in 22 patients with lichen planopilaris

Limited studies have identified an association between frontal fibrosing alopecia (FFA) and leave-on facial skin care products. Although debated, allergic contact dermatitis to these personal care products may contribute to the lymphocytic inflammation affecting the hair follicle unit. This case series sought to identify relevant allergens in patients with lichen planopilaris (LPP) and/or FFA who were seen in an alopecia clinic and referred to patch testing. Patients underwent patch testing with the American Contact Dermatitis Society Core Allergen Series I-VIII, Cosmetic and Hairdresser Series in addition to 8 other potential allergens. Patch tests were applied to the back and read at 48 and 96 hours. Equivocal (+/-) reactions were not included in the results. Between January 2018 and December 2018, 22 female patients with a mean age of 60 years old (range 30-75) underwent patch testing. The majority of patients were Caucasian (95%) and either peri- or post-menopausal (90%) with histological and clinical evidence of LPP (55%), FFA (36%), or LPP/FFA overlap (9%). In total, 77% of patients demonstrated clinically relevant allergens found in cosmetics and personal care products applicable to the head and neck. The mean number of relevant positive allergens was 2 (range 1-8) with more than one-fourth of patients having 4 or more relevant allergens. Half of the patients (50%) had allergens relevant to both facial skin and hair care products. Fragrance mix and fragrance cross reactors (23%), ammonium persulfate (18%), MI and MCI/MI (18%), and dodecyl gallate (18%) represented the most common relevant allergens in these patients. The overall prevalence of patients with relevant positive allergens in this case series (77%) was higher than previous studies which reported on all positive allergens in Brazilian (59%) and British patients (53%) with FFA exclusively. Given the prevalence of relevant contact allergens in females with LPP/FFA, clinicians may consider patch testing for this patient population.

Effects of alkyl gallates, fatty acids, and acylglycerols on the growth of the psychrotolerant bacterium Sporosarcina sp. S92h

Abstract Sporosarcina species are psychrotolerant endospore-forming bacteria that are predominantly isolated from processed minced fish meat (surimi). Their levels should be controlled to maintain the quality of surimi-based food products. Our previous study suggested that the fatty acid composition of the cell membrane is an important factor for the growth of Sporosarcina species under cold conditions. In this study, we examined the effects of alkyl gallates, fatty acids, and acylglycerols on the growth of Sporosarcina sp. S92h in TSB medium at 10 °C and 30 °C. The results illustrated that the alkyl gallates isoamyl gallate, octyl gallate, and lauryl gallate; the fatty acids oleic acid, linoleic acid, and α-linolenic acid; and the acylglycerol monolaurin inhibited the growth of Sporosarcina sp. S92h for 10 days at 10 °C at a concentration of 0.2 mM. We found that compounds that exerted significant growth-inhibitory effects have similar molecular weights (range, 240.3–338.4) and ACD/LogP values (range, 3.48–7.70). These data will be useful for exploring more effective compounds to inhibit the growth of Sporosarcina species and contribute to quality control for surimi-based foods.

Improvement in Nutritional Attributes of Rice Starch with Dodecyl Gallate Complexation: A Molecular Dynamic Simulation and in Vitro Study.

To improve starch functionalities such as digestibility and antioxidant activity, rice starch was complexed with antioxidant dodecyl gallate (DG). Molecular dynamics simulation showed that the starch-DG inclusion complex was favorable, and in 50 ns, the dodecyl segment resided in the helix of the amylose cavities but the gallate tail left outside. This theoretical finding was validated by UV-vis spectroscopy, calorimetric, and crystalline measurements, indicating V-type crystalline structures containing type I and type II inclusion complexes can be formed after DG complexation. Meritedly, starch digestibility was mitigated by synchronously increasing slowly digestible starch (5.12-22.83%) and resistant starch content (8.69-14.17%), and the antioxidant activity was also significantly increased. Such inclusion complexes thereby acted as a carrier for targeting delivery of DG to the human lower gastrointestinal tract with potent antioxidant activity. Complexation with DG synergistically improved starch digestibility and antioxidant activity, favoring the intervention against chronic diseases, by ameliorating the postprandial glycemic response and oxidative stress.

Trapping of glyoxal by propyl, octyl and dodecyl gallates and their mono-glyoxal adducts

Glyoxal (GO) is one of the major toxic intermediates generated during lipid oxidation and degradation. We investigated the inhibitory activities and mechanisms of propyl, octyl, and dodecyl gallates (PG, OG, and DG) on the formation of GO in buffer and during thermo-processing of corn oil, and the anti-carbonyl and antioxidative activities of the mono-GO adducts of PG, OG, and DG. Our results suggested that alkyl gallates could more effectively trap GO than gallic acid. The major mono-GO adducts of PG, OG, and DG were purified and their structures were elucidated based on their 1H, 13C, 2D-NMR, and HRMS data. We further demonstrated that the mono-GO (MG) adducts retained the anti-carbonyl and antioxidative activities. This is the first study to demonstrate that alkyl gallates, the popular food additives, could prevent not only food oxidation, but also the formation of toxic reactive carbonyl species and their corresponding advanced glycation end products (AGEs) during food processing.

Modulating the interfacial concentration of gallates to improve the oxidative stability of fish oil-in-water emulsions

Distributions of a homologous series of gallic acid (GA) derivatives of increasing lipophilicity were determined in stripped fish oil-in-water emulsions. The distribution was determined by employing a kinetic method based on the reaction between the hydrophobic 4-hexadecylbenzenediazonium ions (16-ArN2+) and the antioxidants (AOs), that allows to determine the partition constants between the oil-interfacial, POI, and water-interfacial, PWI, regions of the emulsion. Results showed that the antioxidant activity of gallic acid and its derivatives was positively correlated with the percentage of AO at the interface. The percentage of butyl, octyl and dodecyl gallates in the interfacial region is similar but much higher than that of the other derivatives, showing the highest AO efficiency. When increasing the surfactant fraction, the percentage of all compounds at the interface increased but the emulsion stability decreased due to the dilution of AO at the interface region. Both butyl and octyl gallates were found the most suitable AOs to carry out fish oil-in-water emulsions protection. For maximum effectiveness, butyl and octyl gallate should be used with the lowest emulsifier volume fraction necessary to physically stabilize emulsions.

Potential of the association of dodecyl gallate with nanostructured lipid system as a treatment for paracoccidioidomycosis: In vitro and in vivo efficacy and toxicity

Paracoccidioidomycosis (PCM) is a systemic mycosis endemic in Latin America, caused by Paracoccidioides spp. A limited number of antifungal agents are available and the search for new compounds has increased. Additionally, nanostructured lipid system (NLS) has emmerged as an interesting strategy to carrier compounds for the treatment of mycosis. In this work, the antifungal efficacy and toxicity of dodecyl gallate (DOD) associated with a NLS was evaluated through in vitro and in vivo tests. DOD showed good in vitro antifungal activity and low toxicity in lung fibroblasts and zebrafish embryos, but no antifungal efficacy in infected mice, which may have been a result of low bioavailability. On the other hand, the association of DOD + NLS was beneficial and resulted in lower toxicity in lung fibroblasts and zebrafish embryos. In addition, NLS + DOD promoted a significant reduction in the fungal burden of mice lungs and could be a potential therapeutic option against PCM.

Carboxymethyl cellulose and composite films prepared by electrophoretic deposition and liquid-liquid particle extraction

Electrophoretic deposition (EPD) method has been developed for the controlled deposition of carboxymethyl cellulose (CMC) films. CMC has been utilized as a charging and film forming agent for the EPD of composite organic-inorganic films, containing aluminum hydroxide (AH) as a flame-retardant additive. Problems related to AH agglomeration were avoided using different liquid-liquid particle extraction strategies. It was found that lauryl gallate (LG) and hexadecylphosphonic acid (HDPA) exhibit remarkable adsorption on AH particles due to polydentate bonding mechanisms, and thus were used as efficient extracting agents. A conceptually new strategy has been developed for agglomerate-free processing of AH using HDPA as a capping agent for synthesis and an extractor molecule for liquid-liquid extraction. We demonstrated the EPD of composite CMC-AH films, which contained non-agglomerated AH particles, that were uniformly distributed in the CMC matrix. The AH content in the composite films was estimated from the thermal analysis data.

3D Printable Filaments Made of Biobased Polyethylene Biocomposites.

Two different series of biobased polyethylene (BioPE) were used for the manufacturing of biocomposites, complemented with thermomechanical pulp (TMP) fibers. The intrinsic hydrophilic character of the TMP fibers was previously modified by grafting hydrophobic compounds (octyl gallate and lauryl gallate) by means of an enzymatic-assisted treatment. BioPE with low melt flow index (MFI) yielded filaments with low void fraction and relatively low thickness variation. The water absorption of the biocomposites was remarkably improved when the enzymatically-hydrophobized TMP fibers were used. Importantly, the 3D printing of BioPE was improved by adding 10% and 20% TMP fibers to the composition. Thus, 3D printable biocomposites with low water uptake can be manufactured by using fully biobased materials and environmentally-friendly processes.

Properties of Artificial Phospholipid Membranes Containing Lauryl Gallate or Cholesterol

Lauryl gallate (LG) is an antioxidant agent. However, it exhibits poor solubility in water. Its interactions with the membrane result in structure evolution thus affecting the membrane functionality. In this paper the Brewster angle microscope coupled with the Langmuir trough was applied to determine the morphology, phase behaviour, thickness and miscibility of ternary Langmuir monolayers with equal mole fractions of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC); 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and an increasing mole fraction of LG. The results were discussed as regards analogous systems where cholesterol (Chol) was the third component. Moreover, the phosphatidylcholine–lauryl gallate (PC–LG) interactions were monitored by the attenuated total reflectance Fourier transform infrared spectroscopy and time-of-flight secondary ion mass spectrometry. Besides lipid composition, the addition of LG was found to be a significant factor to modulate the model membrane properties. The LG molecules adjust themselves to the PC monolayer structure. The hydrophobic fragment is dipped into the membrane interior while the hydroxyl groups of phenolic gallate moiety associate with the polar groups of PC mainly through hydrogen bonding inducing the compacting effect. LG is found to be deeply submerged within DOPC, closer to the double bonds, and its insertion practically does not affect the DPPC/DOPC membrane fluidity. This is crucial for getting more profound insight into the role of LG in stabilizing the non-raft domains, mostly exposed to oxidation in which LG can co-localize and serve its antioxidant function.

Lauryl Gallate Induces Apoptotic Cell Death through Caspase-dependent Pathway in U87 Human Glioblastoma Cells In Vitro.

The treatment of human glioma tumor is still an unmet medical need. Natural products are always promising resources for discovery of anticancer drugs. Lauryl gallate (LG) is one of the derivatives of gallic acid, widely present in plants, that has been shown to induce anticancer activities in many human cancer cell lines; however, it has not been studied in human glioma cell lines. Thus, the effects of LG on human glioblastoma U87 cells were investigated in the present in vitro study. Cell morphology and viability were examined by phase-contrast microscopy. Annexin V/Propidium iodide (PI) double staining were performed and assayed by flow cytometry to confirm that viable cell number reduction was due to the induction of apoptosis. Furthermore, U87 cells were exposed to LG in various concentrations and were analyzed by caspase activity assay. To further confirm that LG induced apoptotic cell death, the expression of apoptosis-associated proteins in LG-treated U87 cells was tested by western blot. LG induced morphological changes and decreased viability in U87 cells. Annexin V/PI double staining revealed that LG induced apoptotic cell death in U87 cells in a dose-dependent manner. The increased activities of caspase-2, -3, -8 and -9 demonstrated that LG induced U87 cell apoptosis through a caspase-dependent pathway. In terms of molecular level, LG increased pro-apoptotic proteins Bax and Bak and decreased anti-apoptotic protein Bcl-2 in U87 cells. Furthermore, LG also suppressed the expression of p-Akt, Pak1, Hif-1α and Hif-2α, β-catenin and Tcf-1 in U87 cells. These results suggest that LG induced apoptotic cell death via the caspase-dependent pathway in U87 cells.

Activity of gallic acid and its ester derivatives in Caenorhabditis elegans and zebrafish (Danio rerio) models.

Gallic acid and its ester derivatives have shown antifungal activity in vitro. This study was performed to investigate their activity against Candida albicans and their toxicity in the animal models Caenorhabditis elegans and zebrafish embryos. The compounds protected worms from C. albicans infection. The dodecyl gallate was the most effective. In zebrafish embryo, gallic acid and dodecyl gallate were the least toxic. Gallic acid and its ester derivatives have potential for in vivo use against C. albicans infection. The antifungal effects and toxicity of gallate esters in these alternative animal models were dependent on carbon chain length.

Enzymatic-Assisted Modification of Thermomechanical Pulp Fibers To Improve the Interfacial Adhesion with Poly(lactic acid) for 3D Printing

The present study is about the enzymatic modification of thermomechanical pulp (TMP) fibers for reduction of water uptake and their use in bio-based filaments for 3D printing. Additionally, TMP was used as a fiber reinforcing material and poly(lactic acid) (PLA) as the polymer matrix. The hydrophilic TMP fibers were treated via laccase-assisted grafting of octyl gallate (OG) or lauryl gallate (LG) onto the fiber surface. The modified TMP fibers showed remarkable hydrophobic properties, as demonstrated by water contact angle measurements. Filaments reinforced with OG-treated fibers exhibited the lowest water absorption and the best interfacial adhesion with the PLA matrix. Such higher chemical compatibility between the OG-treated fibers and the PLA enabled better stress transfer from the matrix to the fibers during mechanical testing, which led to the manufacture of strong filaments for 3D printing. All of the manufactured filaments were 3D-printable, although the filaments containing OG-treated fibers yie...

Delayed Patch-Test Reading After 5 Days: An Update From the Mayo Clinic Contact Dermatitis Group.

Patch-test readings after day 5 have previously been used to identify delayed reactions to metals and topical antibiotics. The aims of this study were to identify allergens for which late readings (beyond day 5) would be most valuable and to compare our results with our previous study on delayed patch-test readings. This was a retrospective study of 298 patients who underwent metal and corticosteroid series patch testing from January 1, 2007, through December 31, 2013. Patch-test readings were conducted on days 3 and 5 and at least once sometime between days 7 and 14. All reactions were examined at each reading. These results were concordant with our previous findings that additional readings after day 7 are particularly useful for identifying reactions to metals (gold, cobalt, beryllium, palladium), specific preservatives (dodecyl gallate, propolis), and the topical antibiotic neomycin. New delayed reactions to bacitracin, p-phenylenediamine, and topical corticosteroids were not seen in this cohort.

Electrochemical sensor for dodecyl gallate determination based on electropolymerized molecularly imprinted polymer

An electrochemical sensor based on molecularly imprinted polymer (MIP) film for dodecyl gallate detection at the surface of a glassy carbon electrode (GCE) was proposed in this paper. The GCE was modified with f-MWCNT and the MIP synthesis was performed in situ by means of electropolymerization using ortho-phenylenediamine as the monomer. The stepwise preparation of the MIP and NIP (non-imprinted polymer) was characterized electrochemically by means of cyclic and square wave voltammetry employing ferrocyanide/ferricyanide as a redox probe. The selective capacity performance of the MIP and its imprinted effect to the template molecule (analyte) was compared to the NIP. They were also characterized by scanning electron microscopy technique (SEM). The analytical performance of the MIP sensor performed using square wave voltammetry showed linear range from 0.50 to 8.0×10−9molL−1, with a correlation coefficient of 0.9921. The sensor presented detection and quantification limit of 0.22×10−9 and 0.67×10−9molL−1, respectively. The apparent dissociation constant (KD) calculated was of 1.26×10−4molL−1 and 5.27×10−1molL−1 for the MIP and NIP respectively.

Synthesis, liquid – Liquid extraction and deposition of hydroxyapatite nanorod composites

Hydroxyapatite (HA) nanorods were prepared by a wet chemical precipitation method. Lauryl gallate (LG) and hexadecylphosphonic acid (HDPA) showed strong adsorption on HA and allowed for the transfer of the synthesized HA nanorods from the aqueous to n-butanol phase at the interface of the two immiscible liquids. The extracted non-agglomerated HA particles were used for the fabrication of composite HA-polymer films. In this approach, the problems related to particle agglomeration during the drying stage were avoided. The analysis of the adsorption mechanisms indicated that LG and HDPA are promising extractors for agglomerate free processing of nanomaterials in the liquid-liquid extraction method.

Gallate Contact Dermatitis: Product Update and Systematic Review.

Allergic contact dermatitis related to cosmetic use can result from allergens not routinely evaluated by standard patch test protocols. Propyl, octyl, and dodecyl gallates are commonly used antioxidant preservatives with reports of associated allergic contact dermatitis in the literature. The objectives of this review were to investigate the role of gallates in allergic contact dermatitis and to explore products containing these preservatives. A systematic review of the literature through April 2016 was performed to explore cases of reported gallate allergy. Food and cosmetic product databases were searched for products containing gallates. Seventy-four cases of gallate contact allergy have been reported. In addition, a variety of commercially available cosmetic products and foods contain gallate chemicals. Propyl gallate is the most commonly reported gallate contact allergen and often causes facial and/or hand dermatitis.

Investigating Photocurable Thiol‐Yne Resins for Biomedical Materials

This study deals with the investigation of photocurable thiol‐yne resins covering several important aspects for the production of medical devices by UV‐based manufacturing processes. In this context, the performance of different low‐toxic photoinitiators (PIs) and stabilizers are evaluated in thiol‐yne formulations based on di(but‐1‐yn‐4‐yl) carbonate and various multifunctional thiol monomers. Photodifferential scanning calorimetry measurements reveal that the conversion of all resin formulations is mostly independent on the type and concentration of the applied photoinitiator; however, significant differences in their curing speed are observed. It turns out that the migration of an alkyne derivatized photoinitiator is significantly reduced while providing almost similar photoactivity as its nonfunctionalized reference. Moreover, it is found that lauryl gallate and butylated hydroxytoluene lead to significant stabilization without affecting the overall photoreactivity. Notably, the thermomechanical properties of the investigated photopolymers are only slightly affected by water absorption. Using ester free thiols, water absorption can be reduced and hydrolytically stable polymers are realized. These results highlight the versatility of the present thiol‐yne system for the production of medical materials by photopolymerization. image

Gallic Acid and Dodecyl Gallate Prevents Carbon Tetrachloride-Induced Acute and Chronic Hepatotoxicity by Enhancing Hepatic Antioxidant Status and Increasing p53 Expression.

Gallic acid (3,4,5-trihydroxybenzoic acid, GA), a natural phenolic acid has been reported as a strong antioxidant. Therefore the present study was designed to evaluate the effects of GA and dodecyl gallate (DGA) against acute and chronic carbon tetrachloride (CCl4)-induced hepatotoxicity. For acute model, rats were orally treated with GA and DGA for 7 d prior to CCl4 by intraperitoneally (i.p.) injection. For the chronic model, rats were orally treated with GA or DGA and CCl4 i.p. twice a week for four weeks. In both acute and chronic models, the CCl4-treated groups showed significantly increase in serum hepatic enzyme activities and histopathologic alterations, as well as a disruption in antioxidative status. In contrast, the treatment with GA and DGA restored serum hepatic enzymes activities, improved histopathologic alterations, increased glutathione (GSH) and decreased lipid peroxidation levels. The activities of liver antioxidant enzymes were increased by GA and DGA only in acute model. The expression of p53 gene increased about 3.5 times after GA and DGA treatments, which could result in cell death of damaged hepatocytes preventing of a lifelong liver failure. Thus, these results suggest that GA and DGA has the potential to prevent liver damages as the case of fibrosis condition.