Chemical composition and potential antioxidant, anti-inflammatory, and analgesic efficacy of Cistus albidus L.

This study aims to assess the chemical composition of the aqueous extract of Cistus albidus L. leaves, as well as the potential of aqueous and hydroethanol extracts of the leaves and seeds as analgesic, anti--inflammatory, and antioxidant agents. The contents of phenolics and inorganic constituents were determined in C. albidus seeds and leaves; antioxidant capacity was assessed by 3 complementary and diverse tests. The carrageenan-induced paw edema technique was used to investigate the anti-inflammatory effect in vivo, and albumin denaturation to evaluate the anti-inflammatory effect in vitro. The acetic acid-induced contortion test, the tail-flick test, and the plantar test were used to assess the analgesic effi cacy in vivo. Chemical analysis was performed by UPLC-MS/MS to quantify several phenolic compounds including catechin (1,627.6 mg kg-1), quercitrin (1,235.8 mg kg-1) and gallic acid (628. 2 mg kg-1). The ICP analysis revealed that potassium and calcium were the main inorganic components in the seeds and leaves of C. albidus. The hydroethanolic extract of the leaves showed the highest content of polyphenols/flavonoids, whereas the highest value of proantho cyanidins was detected in the aqueous extract of the seeds. All extracts showed potent antioxidant activity related to different phenolic compounds (quercetin, gallic acid, astragalin, catechin, and rutin). The aqueous extract of the leaves strongly inhibited paw edema (76.1 %) after 6 h of treatment and showed maximal inhibition of protein denaturation (191.0 µg mL-1 for 50 % inhibition) and analgesic activity in different nociceptive models. The presented data reveal that C. albidus extracts potentially show antioxidant, anti-inflammatory, and analgesic activities that could confirm the traditional use of this plant.

Combined administration of gallic acid and glibenclamide mitigate systemic complication and histological changes in the cornea of diabetic rats induced with streptozotocin.

PURPOSE: To determine the effect of gallic acid or its combination with glibenclamide on some biochemical markers and histology of the cornea of streptozotocin (STZ) induced diabetic rats. METHODS: Following induction of diabetes, 24 male albino rats were divided into four groups of six rats each. Groups 1 and 2 (control and diabetic) received rat pellets and distilled water; group 3 (gallic acid) received rat pellets and gallic acid (10 mg/kg, orally) dissolved in the distilled water; and group 4 (gallic acid + glibenclamide) received rat pellets, gallic acid (10 mg/kg, orally), and glibenclamide (5 mg/kg, orally) dissolved in the distilled water. The treatments were administered for three months after which the rats were sacrificed after an overnight fast. Blood and sera were collected for the determination of biochemical parameters, while their eyes were excised for histology. RESULTS: STZ administration to the rats induced insulin resistance, hyperglycemia, microprotenuria, loss of weight, oxidative stress, inflammation, and alteration of their cornea histology, which was abolished following supplementation with gallic acid or its combination with glibenclamide. CONCLUSIONS: The study showed the potentials of gallic acid and glibenclamide in mitigating systemic complication and histological changes in the cornea of diabetic rats induced with STZ.

Gallic acid ameliorates colitis by trapping deleterious metabolite ammonia and improving gut microbiota dysbiosis.

Gut microbiota dysbiosis is causally related to inflammatory bowel disease (IBD), and increased levels of the gut metabolite ammonia have been proposed to contribute to IBD development. In this study, we aimed to clarify the anti-colitis mechanism of gallic acid (GA) based on its ability to trap the deleterious metabolite ammonia and improve gut microbiota. Aminated product was detected in the fecal samples of mice after oral gavage of gallic acid (GA) and identified as 4-amino-substituted gallic acid (4-NH2-GA), thus confirming the ability of GA to trap ammonia in vivo. Then, we compared the beneficial effects of GA and 4-NH2-GA on dextran sulfate sodium (DSS)-induced colitis mouse and found that both compounds managed to alleviate colitis phenotypes, indicating ammonia trapping had no adverse effect on the original anti-colitis activity of GA. In addition, both GA and 4-NH2-GA improved the gut microbiota dysbiosis induced by DSS, and fecal microbiota transplantation was subsequently performed, which further revealed that the gut microbiota mediated the anti-colitis activity of both GA and 4-NH2-GA. In summary, this study clarified that GA alleviated colitis by targeting both the symptoms and root causes: it directly reduced the deleterious metabolite ammonia by forming aminated metabolites without compromising the original anti-colitis activity, and it also improved gut microbiota dysbiosis, which in turn contributed to the alleviation of colitis. Since the GA structure is presented in various polyphenols as a common building block, the novel anti-colitis mechanism obtained from GA may also apply to other complex polyphenols.IMPORTANCEThe dysbiosis of the gut microbiota and its metabolism directly cause the emergence of IBD. In this study, we aimed to clarify the anti-colitis mechanism of GA in sight of gut microbiota and its metabolite ammonia. We discovered that GA directly captured and reduced the harmful metabolite ammonia in vivo to produce the aminated metabolite 4-NH2-GA, while the amination of GA had no adverse effect on its initial anti-colitis activity. In addition, both GA and its aminated metabolite improved the gut microbiota in colitis mice, and the modified gut microbiota, in turn, helped to relieve colitis. Since the GA structure is presented in diverse polyphenols as a common building block, the novel anti-colitis mechanism targeting the symptoms and root causes might also apply to other complex polyphenols.

Gallic acid regulates immune response in a mouse model of rheumatoid arthritis.

INTRODUCTION: Previous studies revealed that gallic acid (GA) exerts anti-inflammation and immuno-regulatory properties. This study aims to explore the pharmacological activities of GA in collagen-induced arthritis (CIA) mouse model. METHODS: Male DBA/1J mice were used to construct the CIA model. The mice were administrated with GA for 3 weeks. Clinical arthritis scores and hind paw volume were evaluated over the experimental period. qPCR and Western blot analysis were used to determine the levels of matrix metallopeptidases (MMPs) and cytokines. In addition, flow cytometry was used to measure the populations of Th17 and Treg cells. ELISAs were used to determine the cytokines in the serum and ankle joint tissues. RESULTS: Treatment of GA (40 and 80 mg/kg/d) reduced clinical arthritis scores and hind paw volume in the CIA mouse model. Besides, treatment of GA reduced the overexpression of MMPs and modulated the dysregulation of inflammation-related cytokines. Flow cytometry showed that treatment of GA decreased the population of Th17 cells, and increased the population of Treg cells, as supported by treatment of GA regulated the Th17/Treg-related cytokines. CONCLUSIONS: GA attenuates symptoms in the CIA mouse model by anti-inflammation and regulating Th17/Treg cell imbalance.

Gallic acid: Pharmacological activities and molecular mechanisms involved in inflammation-related diseases.

Gallic acid (GA), also known as 3,4,5-trihydroxybenzoic acid, is a natural secondary metabolite and widely isolated from various fruits, plants and nuts. In recent years, GA has received increasing attention for its powerful anti-inflammatory properties. The purpose of this review is to clearly illuminate the pharmacological activities and related molecular mechanisms of GA in inflammatory diseases. After consulting a large number of literatures, we made a comprehensive exposition on the chemical characteristics, plant origins, pharmacokinetics and toxicity of GA, especially its pharmacological activities and mechanisms of action. Although the plant source of GA is very rich, its lower extraction rate limits the application of GA in development. It is worth mentioning that GA can not only be separated from many plants, but also be produced in large quantities through biological and chemical synthesis. According to pharmacokinetic studies, the absorption and elimination of GA after oral administration are fast, while the structural optimization or dosage form adjustment of GA is beneficial to increase its bioavailability. Promisingly, toxicity studies have shown that GA scarcely has obvious toxicity or side effects in a variety of animal experiments and clinical trials. The results show that the anti-inflammatory mechanisms of GA mainly involved MAPK and NF-κB signaling pathways. It thus weakens the inflammatory response by reducing the release of inflammatory cytokines, chemokines, adhesion molecule and cell infiltration. Due to its excellent pharmacological activities, GA is expected to be a potential candidate for the treatment of various inflammation-related diseases. This paper will provide theoretical basis for the clinical application of GA and guide the future research and medicinal development of GA.

Expanding Patch Testing Beyond the Baseline Series: Usefulness of Customized Antimicrobials, Vehicles, and Cosmetics Series.

BACKGROUND: Testing cosmetics and their ingredients is essential to avoid missing relevant allergens and to monitor fluctuating incidence of hypersensitivity. OBJECTIVE: The aim of this study was to review the usefulness of patch testing with a customized antimicrobials, vehicles, and cosmetics (AVC) series over 15 years at a single Canadian site. METHODS: Between January 1, 2005, and December 31, 2019, patients suspected of having cosmetics allergy were patch tested with a 40-allergen AVC series in addition to the North American Contact Dermatitis Group standard screening series. We reviewed the patch test results of 2868 patients. RESULTS: We consecutively patch tested with the baseline series 6103 patients, of which 2868 (47%) were also tested with the AVC series. Of 53 different allergens that were tested at some point, 26 remained in the series throughout the 15-year span. The most common positive allergens were thimerosal (4.52%), polyvidone-iodine (2.25%), propolis (2.06%), sodium metabisulfite (1.94%), dodecyl gallate (1.53%), carmine (1.10%), lauryl glucoside (1.01%), sandalwood oil (0.7%), and tert-butylhydroquinone (0.7%). CONCLUSIONS: Although the expansion of the North American Contact Dermatitis Group standard screening series has decreased the yield from the AVC series from 21.1% to 13.9%, it still remains a useful adjunct for patients suspected of having cosmetics or disinfectants allergy.

Methyl gallate: Selective antileishmanial activity correlates with host-cell directed effects.

Leishmaniasis is a widespread tropical infection caused by different species of Leishmania protozoa. Many of the available drugs against the disease are toxic and in certain cases parasite drug resistance is developed. The discovery of drugs for the treatment of leishmaniasis is a pressing concern. In the present work, we describe in vitro studies of the phenolic compound methyl gallate (MG) against Leishmania (Leishmania) amazonensis and its possible mechanisms of action. The in vitro activity of MG was assayed against L. amazonensis (promastigotes, axenic amastigotes, and intramacrophagic amastigotes). Cytotoxicity tests were performed with J774A.1 macrophages and THP-1 cell derived macrophages. To evaluate mechanisms of action, we analyzed cellular TNF-α, IL-12, IFN-γ, IL-10, IL-6, NO, ROS levels, arginase activity, and structural mechanisms (phagocytic and lysosomal activities) involving macrophage activation. Meglumine antimoniate and amphotericin B were used as reference drugs. It was observed that MG effectively inhibited the growth of both promastigote (IC50 5.71 µM) and amastigote-like forms (EC50 5.39 µM), with much higher selectivity indexes than the reference drugs, being more benign towards J774A.1 macrophages than meglumine antimoniate and amphotericin B, at 1631- and 70.92-fold respectively, with respect to the promastigote form. Additionally, MG proved to be even more active against intracellular amastigotes of the parasite (EC50 4.24 µM). Our results showed that antileishmania activity was associated with increased TNF-α, IL-12, NO and ROS levels, as well as decreased IL-6 and decreased arginase activity. In addition, MG induced increased phagocytic capability, and lysosomal volume in macrophages; structural parameters of microbicidal activity. Taken together, our results suggest that MG may be a promising candidate for new drug development against leishmaniasis.

Multifunctional ZnO NPs-chitosan-gallic acid hybrid nanocoating to overcome contact lenses associated conditions and discomfort.

Contact lenses (CL) provide visual correction but their use may also induce several adverse effects causative of discomfort and conditions that lead to stop or discontinue their use. Discomfort is mainly caused by insufficient wetting, impairment of the antioxidant defence system and eye infections. The current work reports on a single step sonochemical coating of CL with ZnO nanoparticles (NPs), chitosan (CS) and gallic acid (GA). GA and CS are expected to improve the comfort of CL by imparting respectively antioxidant properties and enhanced wettability, while their combination with ZnO NPs provides the CL with antimicrobial properties. The ternary composite coating presents high antibacterial efficiency (>4.5 logs reduction) against S. aureus causative of CL-related conditions, and maintains good biocompatibility (>72%) with human cell lines. The obtained multi-functionality on the CL did not affect their geometry and refractive properties.

Effects of gallic acid and physical exercise on passive avoidance memory in male rat

Learning and memory play main roles in daily life of human, and memory represents the basis of all trainings and learning. The aim of the current study is to investigate the effects of gallic acid and physical exercise on the levels of passive avoidance memory in rat. In this experimental study, 46 rats weighing 200-300 g were randomLy divided to six groups of eight each: including control group, groups treated with 10 and 20 mg/kg gallic acid, group undergoing physical exercise alone, and groups both undergoing physical exercise and treated with 10 and 20 mg/kg gallic acid. The interventions continued for 10 days. After the intervention, passive avoidance memory was measured by shuttle box, blood samples were taken, and serum and brain antioxidant capacity and malondialdehyde (MDA) levels were measured. Secondary latency in shuttle box significantly increased in groups undergoing treadmill exercise and undergoing treadmill exercise + treating 10 and 20 mg/kg gallic acid. In groups treated with 10 and 20 mg/kg gallic acid alone, secondary latency increased significantly. Results confirmed the effects of gallic acid and physical exercise, either alone or combined, in improving memory.

Safety assessment of methanolic extract of Terminalia chebula fruit, Terminalia arjuna bark and its bioactive constituent 7-methyl gallic acid: In vitro and in vivo studies.

Terminalia chebula and Terminalia arjuna were widely used in traditional medicine for the treatment of memory impairment, inflammatory disorders and as an anti-aging agent. However, reports regarding their safety aspects are lacking. Hence, the present study was carried out to investigate the toxicity of methanolic extracts of Terminalia chebula fruit (TCF), Terminalia arjuna bark (TAB) and its bioactive constituent 7- Methyl gallic acid (7MG) under in vitro and in vivo conditions. In vitro toxicity profile of TCF, TAB and 7MG (250-2000 µg/ml) were assessed through cytotoxicity, hemolytic activity, mutagenicity and genotoxicity assays. Results of Ames test, comet assay, MTT and hemolytic assays illustrated that TCF, TAB and 7MG exhibited neither cytotoxic and genotoxic effect in PBMC nor hemolytic activity in RBC and no mutagenic effect in TA 98 and TA 100 up to a limited dose of 2000 µg/ml. Acute and subacute toxicity studies showed no significant change in body weight, behavior, hematology, biochemical parameters, organ weight and histopathology. Over all the results of acute and subacute toxicity studies conclude that oral administration of TCF, TAB and 7MG were observed to be relatively non-toxic and affords practical guidance for selecting safe dose for further clinical trials.

Bismuth Subgallate Toxicity in the Age of Online Supplement Use.

INTRODUCTION: Bismuth salts have been used to treat gastroenterological disorders and are readily available over-the-counter and via the internet. Even though generally considered safe, bismuth compounds can cause a syndrome of subacute, progressive encephalopathy when taken in large quantities. CASE REPORT: We present the case of woman who developed progressive encephalopathy, aphasia, myoclonus, and gait instability after chronically ingesting large amounts of bismuth subgallate purchased from a major online marketing website to control symptoms of irritable bowel syndrome. After extensive neurological work-up, elevated bismuth levels in her blood, urine, and cerebrospinal fluid confirmed the diagnosis of bismuth-related neurotoxicity. She improved slowly following cessation of exposure. CONCLUSION: This case highlights bismuth subgallate as a neurotoxic bismuth formulation and reminds providers of the potential for safety misconceptions of positively reviewed online supplements.

Solid lipid nanoparticles improve octyl gallate antimetastatic activity and ameliorate its renal and hepatic toxic effects.

Metastasis is the main cause of cancer-related death and requires the development of effective treatments with reduced toxicity and effective anticancer activity. Gallic acid derivatives have shown significant biological properties including antitumoral activity as shown in a previous study with octyl gallate (G8) in vitro. Thus, the aim of this work was to evaluate the antimetastatic effect of free and solid lipid nanoparticle-loaded G8 in mice in a lung metastasis model. Animals inoculated with melanoma cells presented metastasis in lungs, which was significantly inhibited by treatment with G8 and solid lipid nanoparticle-loaded G8, named G8-NVM. However, G8-treated mice showed an increase in several toxicological parameters, which were almost completely circumvented by G8-NVM treatment. This study supports the need for pharmacological studies on new potential medicinal plants to treat cancer and can provide new perspectives on using nanotechnology to improve biological activities while decreasing the chemotherapy toxicological effects of anticancer drugs.

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.

Gallic acid-based indanone derivative interacts synergistically with tetracycline by inhibiting efflux pump in multidrug resistant E. coli.

The purpose of the present study was to study the synergy potential of gallic acid-based derivatives in combination with conventional antibiotics using multidrug resistant cultures of Escherichia coli. Gallic acid-based derivatives significantly reduced the MIC of tetracycline against multidrug resistant clinical isolate of E. coli. The best representative, 3-(3',4,'5'-trimethoxyphenyl)-4,5,6-trimethoxyindanone-1, an indanone derivative of gallic acid, was observed to inhibit ethidium bromide efflux and ATPase which was also supported by in silico docking. This derivative extended the post-antibiotic effect and decreased the mutation prevention concentration of tetracycline. This derivative in combination with TET was able to reduce the concentration of TNFα up to 18-fold in Swiss albino mice. This derivative was nontoxic and well tolerated up to 300 mg/kg dose in subacute oral toxicity study in mice. This is the first report of gallic acid-based indanone derivative as drug resistance reversal agent acting through ATP-dependent efflux pump inhibition.

Skin testing of gallic acid-based hair dye in paraphenylenediamine/paratoluenediamine-reactive patients.

Incidence of allergic contact dermatitis (ACD) to para-phenylenediamine (PPD)/paratoluenediamine (PTD) hair dyes is increasing. Hair dyes utilizing gallic acid (GA) may be a safe alternative. However, pretesting is recommended. We investigated the contact sensitivity to ingredients of a dye product; GA, monoethanolamine thioglycolate (MT), l-cystein and ferrous sulfate, and an appropriate pretest method in 31 patients reactive to PPD and/or PTD. An open test was performed with the test dye following the patch test. Subsequently, a use test was performed twice, with a 4-week interval. One subject showed a positive reaction to ferrous sulfate in the patch test. Another subject reacted to the first compound alone in the open test. Thirteen subjects manifesting cutaneous lesions from previous regular hair dyeing, showed reactions at the first use of the test dye; and six had reactions with reduced severity at the second test. GA and MT are safe for use in ACD patients reactive to PPD and/or PTD. For predicting contact allergy to hair dyes, the open test appeared to be a better pretest method than the patch test.

Gallic acid exhibits risks of inducing muscular hemorrhagic liposis and cerebral hemorrhage--its action mechanism and preventive strategy.

Gallic acid (3,4,5-trihydroxybenzoic acid) (GA) occurs in many plants. The adverse effects of GA are seldom cited. GA (6-14 µM) provoked the hemorrhagic liposis of the cervical muscles and intracranial hemorrhage. The cause of these pathological events and the method for prevention are still lacking. Using the chicken embryo model and some selected nutraceutics such as folate, glutathione (GSH), N-acetylcysteine, and vitamin E (Vit E), we carried out this study. Results revealed that the action mechanism of GA involved (i) inducing hypoxia with upregulated gene hif-1α and downregulated ratio vegf-r2/vegf-a, leading to dys-vascularization and myopathy; (ii) impairing cytochrome c oxidase; (iii) stimulating creatine kinase and lactate dehydrogenase release; (iv) eliciting carnitine accumulation and liposis via downregulating gene CPT1; (v) suppressing superoxide dismutase and stimulating NO, H2O2, and malondialdehyde; and (vi) depleting erythrocytic and tissue GSH, resulting in hemorrhage. When both Vit E and GSH were applied to the day 1 chicks, a better alleviation effect was revealed. Conclusively, GA potentially exhibits adverse effect by eliciting hemorrhagic liposis of cervical muscles and cerebral hemorrhage. Supplementation with GSH, Vit E, and N-acetylcysteine is able to ameliorate these adverse effects, warranting the importance of restricting the clinical phytotherapeutic doses of GA and related compounds.

The impact of biopreservatives and storage temperature in the quality and safety of minimally processed mixed vegetables for soup.

BACKGROUND: The combined effects of bioactive agents (tea tree essential oil, propolis extract and gallic acid) and storage temperature on the microbiological and sensory quality of fresh-cut mixed vegetables for soup (celery, leek and butternut squash) were studied with the objective of preserving its quality and safety. RESULTS: Refrigeration temperature was confirmed as the main factor to limit the growth of spoilage and pathogenic microorganisms. Biopreservatives applied on mixed vegetables were effective only when combined with optimal refrigeration temperature (5 °C). Bioactive compounds showed slight effectiveness in controlling the microbiota present in mixed vegetables, although coliforms were greatly reduced by gallic acid and propolis treatments, achieving 0.5-2 log unit reductions during storage. Also, these agents showed antimicrobial activity against endogenous Escherichia coli and inoculated E. coli O157:H7, exerting a bacteriostatic effect and reducing population counts by 0.9-1.2 log CFU g(-1) at 10 days of refrigerated storage. The combination of propolis treatment with refrigerated storage conditions effectively preserved the sensory quality and prolonged the sensory shelf life of fresh-cut mixed vegetables by 3 days. CONCLUSION: The use of natural agents such as propolis extract to preserve the quality and safety of mixed vegetables for soup might be an interesting option to address the concerns of the consumer about the use of synthetic chemical antimicrobials potentially harmful to health.

Effect of JEZTC, a synthetic compound, on proliferation and phenotype maintenance of rabbit articular chondrocytes in vitro.

Antioxidant may provide anti-arthritic effect that contributes to resolution of inflammation. Gallic acid (GA) and its derivatives were reported to be effective in treatment of arthritis. But GA-suppressed cell proliferation may compromise its effect on chondro-protection. In this study, we synthesized sulfonamido-based gallate-JEZTC and investigated its effect on rabbit articular chondrocytes through examination of the cell proliferation, morphology, viability, glycosaminoglycan (GAG) synthesis, and cartilage-specific gene expression. Results showed that JEZTC could effectively promote chondrocyte growth and enhance secretion and synthesis of cartilage extracellular matrix (ECM) by upregulating expression levels of aggrecan, collagen II, and Sox9 genes. Expression of collagen I which marked chondrocyte dedifferentiation was effectively downregulated by JEZTC. In addition, hypertrophy that may lead to chondrocyte ossification could not be detected in JEZTC groups. The results indicated JEZTC can well preserve the phenotype of chondrocytes. Range of 2.344 to 9.375 µg/ml is the recommended dose of JEZTC, which showed increased cell proliferation. Especially, JEZTC of 4.688 µg/ml showed the best performance. This study might provide a basis for development of a novel agent for the treatment of symptomatic chondral and osteochondral lesions.

Contact sensitization to cosmetic series of allergens in a general population in Beijing.

Cosmetic allergic contact dermatitis (CACD) due to common cosmetic allergens in standard series has been extensively studied; however, the prevalence of contact allergy to other cosmetic allergens other than those in standard series is largely unknown. In this study, the frequency of contact sensitization to a European cosmetic series of allergens (Chemotechnique Diagnostics, Vellinge, Sweden) in healthy university student volunteers were detected in Beijing. Of 201 students studied, fifty-eight exhibited positive results, and 9 of them reported had cosmetics related dermatitis previously. The total positivity rate was not correlated to gender. The leading allergens were thimerosal (19.4%), shellac (3.0%), cocamidopropyl betaine (2.0%), hexamethylenetetramine (1.5%), dodecyl gallate (1.5%), hexahydro-1,3,5-tris-(2-hydroxyethyl)triazine (1.0%) and methyldibromo glutaronitrile (1.0%). The positivity rate of thimerosal patch test in men (9.8%) was lower than that of women (23.6%, P < 0.05, Chi square test), but no difference could be found between the prevalence of other cosmetic allergens in men and women (P > 0.05, Chi square test). These results suggested that some cosmetic-related contact allergies may be missed by just testing patients with the European standard series or T.R.U.E. test system only, we recommend shellac, cocamidopropyl betaine, hexamethylenetetramine and dodecyl gallate as the additionally candidates for patch testing in patients with suspected CACD.

Gallic acid improves glucose tolerance and triglyceride concentration in diet-induced obesity mice.

Gallic acid, a phenolic phytochemical, has been shown to exert a variety of effects, including anti-oxidative, anti- carcinogenic, anti-allergic, and anti-inflammatory effects. In this study, we attempted to determine whether gallic acid affects metabolic syndrome such as obesity and diabetes. Diet-induced obesity mice were treated intraperitoneally once per day with gallic acid (10 mg/kg/day). After 2 weeks of treatment, the mice were sacrificed to collect the blood for metabolic parameter assessments, and the adipose tissues and liver to weigh and analyze. The triglyceride concentrations were significantly improved in the gallic acid group relative to those measured in the control group. And most importantly, the blood glucose concentrations in the gallic acid group were significantly improved. In the epididymal white adipose tissue of the gallic acid group, adipocyte size was reduced, PPARγ expression was induced, and the Akt signaling pathway was activated. Our results demonstrate that gallic acid improves glucose tolerance and lipid metabolism in the obesity mice, thereby showing evidence of anti-hyperglycemic activity. The findings of an upregulation of PPARγ expression and Akt activation also contribute to our current understanding of the mechanisms underlying the effects of gallic acid on glucose metabolism.