Synergy of histone acetyltransferase inhibitor (HATi) with quercetin inhibits biofilm formation in Candida tropicalis.

Histone acetyltransferase inhibitors (HATi) are mechanism-based inhibitors that show promise in the treatment of several illnesses, including diabetes, hyperlipidemia, cancer, and Alzheimer's disease. The work emphasizes the significance of HATi as a possible treatment strategy against Candida species biofilms. Here, in this study, we found that combining a HATi, anacardic acid (AA), and quercetin, a known flavonoid, significantly prevented biofilm formation by C. tropicalis. We further show that C. tropicalis exhibited a considerable downregulation of drug-resistance gene expression (CDR1 and MDR1) when co-administrated. Additionally, in silico studies revealed that the AA interacts strongly with a histone acetyltransferase, Rtt109, which may account for the observed biofilm inhibitory effect. In conclusion, the study illustrates how HATi may be used to potentiate the inhibitory action of phytoactives or antifungals against drug-resistant yeast infections.

Integrated Metabolomics and Transcriptomics Analysis of Anacardic Acid Inhibition of Breast Cancer Cell Viability.

Anacardic acid (AnAc) inhibits the growth of estrogen receptor α (ERα)-positive MCF-7 breast cancer (BC) cells and MDA-MB-231 triple-negative BC (TNBC) cells, without affecting primary breast epithelial cells. RNA sequencing (seq) and network analysis of AnAc-treated MCF-7 and MDA-MB-231 cells suggested that AnAc inhibited lipid biosynthesis and increased endoplasmic reticulum stress. To investigate the impact of AnAc on cellular metabolism, a comprehensive untargeted metabolomics analysis was performed in five independent replicates of control versus AnAc-treated MCF-7 and MDA-MB-231 cells and additional TNBC cell lines: MDA-MB-468, BT-20, and HCC1806. An analysis of the global metabolome identified key metabolic differences between control and AnAc-treated within each BC cell line and between MCF-7 and the TNBC cell lines as well as metabolic diversity among the four TNBC cell lines, reflecting TNBC heterogeneity. AnAc-regulated metabolites were involved in alanine, aspartate, glutamate, and glutathione metabolism; the pentose phosphate pathway; and the citric acid cycle. Integration of the transcriptome and metabolome data for MCF-7 and MDA-MB-231 identified Signal transduction: mTORC1 downstream signaling in both cell lines and additional cell-specific pathways. Together, these data suggest that AnAc treatment differentially alters multiple pools of cellular building blocks, nutrients, and transcripts resulting in reduced BC cell viability.

Anacardic acid induces IL-33 and promotes remyelination in CNS.

Given the known neuroreparative actions of IL-33 in experimental models of central nervous system (CNS) injury, we predicted that compounds which induce IL-33 are likely to promote remyelination. We found anacardic acid as a candidate molecule to serve as a therapeutic agent to promote remyelination. Addition of anacardic acid to cultured oligodendrocyte precursor cells (OPCs) rapidly increased expression of myelin genes and myelin proteins, suggesting a direct induction of genes involved in myelination by anacardic acid. Also, when added to OPCs, anacardic acid resulted in the induction of IL-33. In vivo, treatment of with anacardic acid in doses which ranged from 0.025 mg/kg to 2.5 mg/kg, improved pathologic scores in experimental allergic encephalitis (EAE) and in the cuprizone model of demyelination/remyelination. Electron microscopic studies performed in mice fed with cuprizone and treated with anacardic acid showed lower g-ratio scores when compared to controls, suggesting increased remyelination of axons. In EAE, improvement in paralytic scores was seen when the drug was given prior to or following the onset of paralytic signs. In EAE and in the cuprizone model, areas of myelin loss, which are likely to remyelinate, was associated with a greater recruitment of IL-33-expressing OPCs in mice which received anacardic acid when compared to controls.

Anacardic Acid Derivatives Affect the in Vitro Reactions of Photosynthesis.

The dichloromethane extract of the cashew nuts from Anacardium occidentale was fractionated by rotation locular countercurrent chromatography aimed at discovering metabolites that could be useful as new models for photosynthesis inhibitors. The chemical fractionation afforded a complex mixture of anacardic acids, which upon catalytic hydrogenation yielded anacardic acid (1). Methylation of 1 via reaction with diazomethane afforded an ester 2. Both compounds were evaluated using polarographic approaches and fluorescence studies of chlorophyll a (ChL a). The in vitro assays informed the decision for the classification of 1 and 2 as Hill reaction inhibitors. Besides that, 1 inhibited the donor side of the PSII, while 2 acted as an energy transfer inhibitor. Therefore, this study is important for the development of herbicides.

Cashew (Anacardium occidentale) Nut-Shell Liquid as Antioxidant in Bulk Soybean Oil.

Recently, natural antioxidants for the food industry have become an important focus. Cashew nut-shell liquid (CNSL) is composed of compounds that can act as natural antioxidants in food systems. The aim of this work was to evaluate the potential of CNSL and its components to act as natural antioxidants in a bulk oil system. CNSL was treated with calcium hydroxide to obtain two fractions [cardol/cardanols acid fraction (CCF) and anacardic acid fraction (AF)]. CNSL, FF and AF were analyzed by thin-layer chromatography and Fourier-transform infrared spectroscopy. The protective effects of CNSL, CCF and AF were tested in terms of the peroxide value of bulk soybean oil in accelerated assays and were compared against controls with and without synthetic antioxidants (CSA and CWA). CNLS, CCF, AF and CSA were tested at 200 mg/kg soybean oil by incubation at 30, 40, 50 and 60 °C for five days. The activation energy (Ea) for the production of peroxides was calculated by using the linearized Arrhenius equation. Thin-layer chromatography and Fourier-transform infrared spectroscopy revealed that (i) CNSL contained cardanols, anacardic acids, and cardols; (ii) CCF contained cardanols and cardols; and (iii) AF contained anacardic acids. CSA (Ea 35,355 J/mol) was the most effective antioxidant, followed by CCF (Ea 31,498 J/mol) and by CNSL (Ea 26,351 J/mol). AF exhibited pro-oxidant activity (Ea 8339 J/mol) compared with that of CWA (Ea 15,684 J/mol). Therefore, cardols and cardanols from CNSL can be used as a natural antioxidant in soybean oil.

Anacardic 6-pentadecyl salicylic acid induces apoptosis in breast cancer tumor cells, immunostimulation in the host and decreases blood toxic effects of taxol in an animal model.

Many antineoplastic agents induce myelosuppression and leukopenia as secondary effects in patients. The development of anticancer agents that simultaneously provoke antitumor immune response represents an important therapeutic advance. The administration of 6-pentadecyl salicylic acid (6SA) contributes to the antitumor immunity using 4T1 breast cancer cells in Balb/c female mice, with Taxol as a positive control and in cotreatment with 6SA (6SA + Taxol; CoT). Our results show that 6SA reduces tumor volume and size by inducing caspase-8-mediated apoptosis without reducing tumor infiltrated lymphocytes. Also, 6SA reduced lung metastasis and increased the proportion of immune cells in blood, lymph nodes and bone marrow; more evidently, in the proportion of tumor-infiltrated natural killer (NK) cells and cytotoxic T lymphocytes. Taxol reduces helper and cytotoxic lymphocytes causing systemic immunosuppression and myelosuppression in bone marrow, whereas 6SA does not decrease any immune cell subpopulations in circulating blood and lymph nodes. More importantly, the CoT decreased the Taxol-induced cytotoxicity in circulating T cells and bone marrow. Treatment with 6SA increases the secretion of IL-2, IL-12, GM-CSF, TNF-α and IFN-γ and significantly reduces IL-10 and IL-17 secretion, suggesting that the reduction of regulatory T cells and tumor-associated macrophages contribute to the host control of tumor development. Finally, 6SA has an effective antineoplastic activity against breast cancer cells in an immunocompetent animal, reduces the myelosuppression and leukopenia that Taxol produces, improves the antitumoral immunological microenvironment and increases the overall survival of the animals improving the quality of life of patients with cancer.

Anacardic acid-mediated regulation of osteoblast differentiation involves mitigation of inflammasome activation pathways.

Disruption of the finely tuned osteoblast-osteoclast balance is the underlying basis of several inflammatory bone diseases, such as osteomyelitis, osteoporosis, and septic arthritis. Prolonged and unrestrained exposure to inflammatory environment results in reduction of bone mineral density by downregulating osteoblast differentiation. Earlier studies from our laboratory have identified that Anacardic acid (AA), a constituent of Cashew nut shell liquid that is used widely in traditional medicine, has potential inhibitory effect on gelatinases (MMP2 and MMP9) which are over-expressed in numerous inflammatory conditions (Omanakuttan et al. in Mol Pharmacol, 2012 and Nambiar et al. in Exp Cell Res, 2016). The study demonstrated for the first time that AA promotes osteoblast differentiation in lipopolysaccharide-treated osteosarcoma cells (MG63) by upregulating specific markers, like osteocalcin, receptor activator of NF-κB ligand, and alkaline phosphatase. Furthermore, expression of the negative regulators, such as nuclear factor-κB, matrix metalloproteinases (MMPs), namely MMP13, and MMP1, along with several inflammatory markers, such as Interleukin-1ß and Nod-like receptor protein 3 were downregulated by AA. Taken together, AA expounds as a novel template for development of potential pharmacological therapeutics for inflammatory bone diseases.

High glucose-induced oxidative stress accelerates myogenesis by altering SUMO reactions.

Skeletal muscle preservation is a dynamic process that involves constant repair and regeneration. However, the regenerative capacity of muscle cells declines in hyperglycemia. This study aimed to explore the molecular mechanisms underlying this glucotoxicity during myoblast differentiation. C2C12 cells were exposed to different concentrations of glucose, to recapitulate the development of skeletal muscles in vivo in normo- and hyperglycemic conditions. In high glucose conditions, we found significant increases in levels of total cellular reactive oxygen species (ROS) and a reorganization of SUMO enzyme transcripts and SUMOylated proteins. Furthermore, in anticipation of the ROS-induced damage to newly formed myotubes, we observed acceleration of myogenesis. Interestingly, we found a tight relationship between SUMOylation of the Histone methyltransferase SET7/9 and the maintenance of sarcomeric structures of newly formed myotubes. Finally, treatment with the antioxidant anacardic acid preserved the function and activity of myotubes generated in high-glucose conditions by interfering with both ROS and SUMO pathways. Combined, these results suggest that increased oxidative stress and modulation of SUMO reactions are key mediators of glucotoxicity and inhibition of these perturbations using antioxidants might improve muscle regeneration in hyperglycemia.

Anacardic Acids from Amphipterygium adstringens Confer Cytoprotection against 5-Fluorouracil and Carboplatin Induced Blood Cell Toxicity While Increasing Antitumoral Activity and Survival in an Animal Model of Breast Cancer.

Amphipterygium adstringens (cuachalalate) contains anacardic acids (AAs) such as 6-pentadecyl salicylic acid (6SA) that show immunomodulatory and antitumor activity with minimal or no secondary adverse effects. By contrast, most chemotherapeutic agents, such as 5-fluorouracil (5-FU) and carboplatin (CbPt), induce myelosuppression and leukopenia. Here, we investigated the myeloprotective and antineoplastic potential of an AA extract or the 6SA as monotherapy or in combination with commonly used chemotherapeutic agents (5-FU and CbPt) to determine the cytoprotective action of 6SA on immune cells. Treatment of Balb/c breast tumor-bearing female mice with an AA mixture or 6SA did not induce the myelosuppression or leukopenia observed with 5-FU and CbPt. The co-administration of AA mixture or isolated 6SA with 5-FU or CbPt reduced the apoptosis of circulating blood cells and bone marrow cells. Treatment of 4T1 breast tumor-bearing mice with the AA mixture or 6SA reduced tumor growth and lung metastasis and increased the survival rate compared with monotherapies. An increased effect was observed in tumor reduction with the combination of 6SA and CbPt. In conclusion, AAs have important myeloprotective and antineoplastic effects, and they can improve the efficiency of chemotherapeutics, thereby protecting the organism against the toxic effects of drugs such as 5-FU and CbPt.

Purified anacardic acids exert multiple neuroprotective effects in pesticide model of Parkinson's disease: in vivo and in silico analysis.

Parkinson's disease (PD) induced by environmental toxins involves a multifactorial cascade of harmful factors, thus motivating the search for therapeutic agents able to act on the greatest number of molecular targets. This study evaluated the efficacy of 50 mg/kg purified anacardic acids (AAs), isolated from cashew nut shell liquid, on multiple steps of oxidative stress and inflammation induced by rotenone in the substantia nigra (SN) and striatum. Adult mice were divided into four groups: Control, rotenone, AAs + rotenone, and AAs alone. Lipoperoxidation, nitric oxide (NO) levels, and reduced glutathione (GSH)/oxidized gluthatione (GSSG) ratio were evaluated. NF-kB-p65, pro-IL-1ß, cleaved IL-1ß, metalloproteinase-9, Tissue Inhibitory Factor-1 (TIMP-1), tyrosine hydroxylase (TH), and glial fibrillary acidic protein (GFAP) levels were assessed by Western blot. In silico studies were also made using the SwissADME web tool. Rotenone increased lipoperoxidation and NO production and reduced TH levels and GSH/GSSG ratio in both SN and striatum. It also enhanced NF-kB-p65, pro, and cleaved IL-1ß, MMP-9, GFAP levels compared to control and AAs groups. The AAs alone reduced pro-IL-1ß in the striatum while they augmented TIMP1 and reduced MMP-9 amounts in both regions. AAs reversed rotenone-induced effects on lipoperoxidation, NO production, and GSH/GSSG ratio, as well as increased TH and attenuated pro-IL-1ß and MMP-9 levels in both regions, NF-kB-p65 in the SN and GFAP in the striatum. Altogether, the in vivo and in silico analysis reinforced multiple and defined molecular targets of AAs, identifying that they are promising neuroprotective drug candidates for PD, acting against oxidative and inflammatory conditions induced by rotenone.

Anacardic acid inhibits RANKL-induced osteoclastogenesis in vitro and prevents ovariectomy-induced bone loss in vivo.

Postmenopausal osteoporosis is the most common form of primary osteoporosis, and the incidence of the condition is rapidly increasing. In consideration of the limitations of current therapeutic options for the treatment of postmenopausal osteoporosis, there is an urgent need to develop safer alternatives. Anacardic acid, a natural phenolic acid compound extracted from cashew nut shell, possesses potent antitumor and anti-inflammatory effects and inhibits NF-κB signaling. However, its effect on osteoclasts remains unknown. This study reports the first evidence for the antiosteoclastogenic and antiresorptive effects of anacardic acid on bone marrow-derived macrophage-derived osteoclasts. Mechanistically, anacardic acid disrupts the phosphorylation of TGF-ß activated kinase 1 and subsequently suppresses multiple receptor activator of NF-κB ligand-induced signaling cascades, ultimately inhibiting the induction and activation of the crucial osteoclast transcriptional factor nuclear factor of activated T-cell cytoplasmic 1. Consistent with cellular results in vitro, anacardic acid treatment improves bone density in the murine model of ovariectomy-induced bone loss. Taken together, our study provides promising evidence for the therapeutic application of anacardic acid as a new potential pharmacological treatment for osteoporosis.-Zhao, K., Jia, Y., Peng, J., Pang, C., Zhang, T., Han, W., Jiang, J., Lu, X., Zhu, J., Qian, Y. Anacardic acid inhibits RANKL-induced osteoclastogenesis in vitro and prevents ovariectomy-induced bone loss in vivo.

Differential lethal action of C17:2 and C17:0 anacardic acid derivatives in Trypanosoma cruzi - A mechanistic study.

The n-hexane extract from leaves of Schinus terebinthifolius (Anacardiaceae) induced 100% of death of trypomastigote forms of T. cruzi at 300 µg/mL and was subjected to a bioactivity-guided fractionation to afford a C17:2 derivative of anacardic acid [6-(8'Z,11'Z)-heptadecadienyl-salicylic acid, 1]. Additionally, compound 1 was subjected to hydrogenation procedures to afford a C17:0 derivative (6-heptadecanyl-salicylic acid, 1a). Compounds 1 and 1a were effective in killing trypomastigote forms of T. cruzi with IC50 values of 8.3 and 9.0 µM, respectively, while a related compound, salicylic acid, was inactive. Furthermore, no cytotoxicity was observed for the highest tested concentration (CC50 > 200 µM) for all evaluated compounds. Due to the promising results, the mechanism of parasite death was investigated for compounds 1 and 1a using flow cytometry and spectrofluorimetry. The cell membrane permeability assay with SYTOX Green indicated that compound 1 significantly altered this parameter after 40 min of incubation, while compound 1a caused no alteration. Considering that the hydrogenation rendered a differential cellular target in parasites, additional assays were performed with 1a. Despite no permeabilization of the plasma membrane, compound 1a induced depolarization of the electric potential after two hours of incubation. The mitochondria of the parasite were also affected by compound 1a, with depolarization of the mitochondrial membrane potential, and reduction of reactive oxygen species (ROS) levels. The Ca2+ levels were not affected during the time of incubation. Considering that the mitochondrion is a single organelle in Trypanosoma cruzi for ATP generation, compounds affecting the bioenergetic system are of interest for drug discovery against Trypanosomatids.

Anacardic acid attenuates pressure-overload cardiac hypertrophy through inhibiting histone acetylases.

Cardiac hypertrophy has become a major cardiovascular problem wordwide and is considered the early stage of heart failure. Treatment and prevention strategies are needed due to the suboptimal efficacy of current treatment methods. Recently, many studies have demonstrated the important role of histone acetylation in myocardium remodelling along with cardiac hypertrophy. A Chinese herbal extract containing anacardic acid (AA) is known to possess strong histone acetylation inhibitory effects. In previous studies, we demonstrated that AA could reverse alcohol-induced cardiac hypertrophy in an animal model at the foetal stage. Here, we investigated whether AA could attenuate cardiac hypertrophy through the modulation of histone acetylation and explored its potential mechanisms in the hearts of transverse aortic constriction (TAC) mice. This study showed that AA attenuated hyperacetylation of acetylated lysine 9 on histone H3 (H3K9ac) by inhibiting the expression of p300 and p300/CBP-associated factor (PCAF) in TAC mice. Moreover, AA normalized the transcriptional activity of the heart nuclear transcription factor MEF2A. The high expression of cardiac hypertrophy-linked genes (ANP, ß-MHC) was reversed through AA treatment in the hearts of TAC mice. Additionally, we found that AA improved cardiac function and survival rate in TAC mice. The current results further highlight the mechanism by which histone acetylation is controlled by AA treatment, which may help prevent and treat hypertrophic cardiomyopathy.

The antineoplastic agent anacardic 6-pentadecyl salicylic acid produces immunomodulation in vivo via the activation of MAPKs.

Anacardic 6-pentadecyl salicylic acid (6SA) is the active component of Amphipterygium adstringens, a plant used in traditional medicine for the treatment of malaria and vascular diseases and as an anti-bacterial and immune-modulatory agent. However, the effect of 6SA on the immune system remains unclear. In this study, we examined the immune-stimulatory activity of 6SA in 6-8-week-old female BALB/c mice. We found that treatment with 2 mg/kg of 6SA increased the proportions of macrophages after 7 and 14 days of treatment and of natural killer (NK) cells after 14 days of treatment in circulating blood. In lymph nodes, treatment with 6SA for 14 days increased the number of macrophages. In addition, 6SA increases in the systemic levels of pro-inflammatory cytokines such as tumour necrosis factor (TNF)-α, interleukin (IL)-2, IL-12, IL-6 and IL-1ß and of nitric oxide (NO). We observed an increase in the secretion of Granulocyte/Macrophage Colony Stimulation Factor (GM-CSF) that could explain the increase in the proportion of macrophages. Moreover, 6SA induced the classical activation of macrophages by increasing their expression of MHC-II and their production of TNF-α. These M1-polarised macrophages presented enhanced phagocytosis and NO secretion. This activation was due to induction of the phosphorylation of MAPKs such as ERK, JNK and p38 because specific inhibitors of the phosphorylation of these MAPKs reduced the 6SA-induced phagocytosis and NO and particularly, the secretion of GM-CSF in macrophages by inhibition of ERK. Despite these effects on macrophages, 6SA does not have any direct effect on the proportion of lymphocytes.

Effect of anacardic acid against echinococcosis through inhibition of VEGF-induced angiogenesis.

Echinococcosis is a zoonotic infection caused by cestode species of the genus Echinococcus, with limited treatment options. It is urgent to develop new anti-hydatid agent. In this paper, we reported anacardic acid (AA), a natural product isolated from the Brazilian cashew-nut shell liquid, which presented a high activity against metacestodes of Echinococcus multilocularis (E. multilocularis) and Echinococcus granulosus sensu stricto (E. granulosus s.s.) in vitro and in vivo. AA exerted a better efficacy on E. granulosus s.s. protoscoleces and E. multilocularis metacestodes than that of albendazole (ABZ) and dihydroartemisinin (DHA) in vitro, and an inhibition on the growth of Echinococcus metacestode as effective as ABZ in vivo. Moreover, we also found that one of the mechanisms of AA against Echinococcus could be the suppression of angiogenesis on/in the metacestode mass through inhibiting vascular endothelial growth factor (VEGF)-induced signalling pathways. This work finds that AA is a new promising potential candidate drug for echinococcosis treatment.

Antidepressant-like effect of anacardic acid in mice via the L-arginine-nitric oxide-serotonergic system.

Depression, a multifactorial neuronal disorder with high morbidity/mortality, is associated with psychological, psychosocial, hereditary, and environmental etiologies, where reactive species exert pathophysiological functions. Anacardic acid (AA), a natural compound obtained from cashew nut liquid, has several pharmacological activities, including antioxidant and anticonvulsant. The aim of the present study was to evaluate the antidepressant-like effect of AA and the involvement of serotonergic, noradrenergic, and L-arginine-nitric oxide (NO) in tail suspension and forced swim tests and, more so, to investigate its antioxidant effect in Saccharomyces cerevisiae and in male Swiss mice (n = 8). In order to identify the antidepressant mechanisms, AA (10, 25, or 50 mg/kg, p.o.) was given 30 min before clonidine (2-adrenergic receptor agonist), L-arginine (NO precursor), propranolol (ß-adrenergic receptor antagonist), and several other agonists or antagonists used. On the other hand, clonidine, noradrenoreceptor, noradrenaline, and L-arginine were used to identify the antidepressant mechanisms. Results suggest that AA exerts antidepressant-like activity, especially at higher doses, possibly by inhibiting serotonin and 5HT-1A reuptake receptors and by inhibiting NO synthetase and guanylyl cyclase enzymes. Additionally, AA exhibited antioxidant effect in S. cerevisiae. This antioxidant capacity may be linked to its antidepressant-like effect but does not interact with α- and ß-adrenoceptor receptors. In conclusion, AA may be used as a promising agent to treat depression, especially which arises from oxidative stress.

Photoelectrochemical determination of the activity of histone acetyltransferase and inhibitor screening by using MoS2 nanosheets.

The enzyme histone acetyltransferase (HAT) catalyzes the acetylation of a substrate peptide, and acetyl coenzyme A is converted to coenzyme A (CoA). A photoelectrochemical method is described for the determination of the HAT activity by using exfoliated MoS2 nanosheets, phos-tag-biotin, and ß-galactosidase (ß-Gal) based signal amplification. The MoS2 nanosheets are employed as the photoactive material, graphene nanosheets as electron transfer promoter, gold nanoparticles as recognition and capture reagent for CoA, and phos-tag-biotin as the reagent to link CoA and ß-Gal. The enzyme ß-Gal catalyzes the hydrolysis of substrate O-galactosyl-4-aminophenol to generate free 4-aminophenol which is a photoelectrochemical electron donor. The photocurrent increases with the activity of HAT. Under optimal conditions, the response is linear in the 0.3 to 100 nM activity range, and the detection limit is 0.14 nM (at S/N = 3). The assay was applied to HAT inhibitor screening, specifically for the inhibitors C646 and anacardic acid. The IC50 values are 0.28 and 39 µM, respectively. The method is deemed to be a promising tool for epigenetic research and HAT-targeted cancer drug discovery. Graphical abstract Histone acetyltransferase was detected using a sensitive photoelectrochemical method using MoS2 nanosheets as photoactive material.

Anxiolytic effect of anacardic acids from cashew (Anacardium occidentale) nut shell in mice.

Antianxiety drugs currently in use are associated with a number of serious side effects. Present study was designed to evaluate the efficacy of anacardic acids (AAs) isolated from cashew nut (Anacardium occidentale L.) shell liquid (CNSL) to treat anxiety as well as its role in oxidative stress in mice model. Anxiolytic effect of AA was evaluated using rota-rod and a set of behavioral tests in male Swiss albino mice at the doses of 10, 25, and 50 mg/kg. Flumazenil was used to evaluate the possible involvement of GABAergic system in the mechanism of action of AA. The effect of AA on oxidative stress in mice was evaluated by determining the concentration of malondialdehyde (MDA), reduced glutathione, and catalase (CAT) activity. The detection of DNA damage of the treated animals was performed using alkaline comet test in the hippocampus and frontal cortex of the animals. The results demonstrated that AA did not produce myorelaxant and sedative effects, nor did it cause a decrease in locomotor activity. The anxiolytic effect of AA was well-evident in all tests, especially at higher dose levels (25 and 50 mg/mg). Flumazenil reversed the anxiolytic effect of AA at all doses. In addition, AA reduced oxidative stress by decreasing the concentration of MDA and increasing the levels of reduced glutathione (GSH) and CAT activity. Statistical analysis by Pearson's correlation indicated a positive correlation between anxiolytic effect of AA to its antioxidant and lipid peroxidation inhibitory activity. Furthermore, increased CAT activity and GSH concentrations in the hippocampus and frontal cortex of mice was also complementary to the reduced genotoxic damage observed in the study. In comet assay, AA did not increase in DNA damage. In conclusion, the results supported that AA possesses GABAA receptor mediated anxiolytic activity with the lack of myorelaxation and genotoxicity. © 2018 IUBMB Life, 70(5):420-431, 2018.

Anacardic acid suppresses fibroblast-like synoviocyte proliferation and invasion and ameliorates collagen-induced arthritis in a mouse model.

Anacardic acid, which is abundant in nutshell of Anacardium occidentale, has multiple pharmacological activities. In this study, we examined the therapeutic potential of anacardic acid in treating rheumatoid arthritis (RA). We explored the effects of anacardic acid on collagen-induced arthritis (CIA) in mice and on the proliferation and invasion of RA fibroblast-like synoviocytes (RA-FLSs). The underlying molecular mechanism was investigated. Anacardic acid treatment markedly suppressed paw swelling, joint destruction, and arthritis scores in CIA mice. The serum levels of tumor necrosis factor alpha (TNF- α) and interleutkin-1beta (IL- 1ß) were significantly lowered by anacardic acid. In vitro assays demonstrated that anacardic acid impaired the proliferation and invasion abilities of RA-FLSs in the presence of TNF- α or IL- 1ß. Western blot analysis revealed the reduction of Akt protein expression and phoshporylation in RA-FLSs by anacardic acid. However, the mRNA level of Akt remained unchanged. Anacardic acid treatment significantly increased the expression of miR-633 in RA-FLSs. Akt was identified as a novel target of miR-633. Overexpression of miR-633 significantly inhibited the proliferation and invasion of RA-FLSs, which was rescued by enforced expression of Akt. Depletion of miR-633 prevented anacardic acid-mediated suppression of proliferation and invasion of RA-FLSs, which was accompanied by increased expression of Akt protein. In conclusion, anacardic acid may serve as a promising agent in the treatment of RA.

Effects of histone acetyltransferase inhibitors on L-DOPA-induced dyskinesia in a murine model of Parkinson's disease.

Histone acetylation is a key regulatory factor for gene expression in cells. Modulation of histone acetylation by targeting of histone acetyltransferases (HATs) effectively alters many gene expression profiles and synaptic plasticity in the brain. However, the role of HATs on L-DOPA-induced dyskinesia of Parkinson's disease (PD) has not been reported. Our aim was to determine whether HAT inhibitors such as anacardic acid, garcinol, and curcumin from natural plants reduce severity of L-DOPA-induced dyskinesia using a unilaterally 6-hydroxydopamine (6-OHDA)-lesioned PD mouse model. Anacardic acid 2 mg/kg, garcinol 5 mg/kg, or curcumin 100 mg/kg co-treatment with L-DOPA significantly reduced the axial, limb, and orofacial (ALO) score indicating less dyskinesia with administration of HAT inhibitors in 6-OHDA-lesioned mice. Additionally, L-DOPA's efficacy was not altered by the compounds in the early stage of treatment. The expression levels of c-Fos, Fra-2, and Arc were effectively decreased by administration of HAT inhibitors in the ipsilateral striatum. Our findings indicate that HAT inhibitor co-treatment with L-DOPA may have therapeutic potential for management of L-DOPA-induced dyskinesia in patients with PD.