Cashew apple byproduct: Gastroprotective effects of standardized extract.

ETHNOPHARMACOLOGICAL RELEVANCE: The incidence of gastric mucosa lesions in the adult population has increased mainly due to the continued use of nonsteroidal anti-inflammatory drugs (NSAIDs). The cashew (Anacardium occidentale L.) is a tropical tree, cultivated in several countries, whose barks, leaves and pseudofruit (cashew apple) are popularly used in traditional medicine for the treatment of many diseases, including gastric ulcer. AIM: Our study evaluated the potential gastroprotective effect of the carotenoid and anacardic acids-enriched aqueous extract (CAE), prepared from cashew apple pomace, in the dose-repeated acetylsalicylic acid (ASA)-induced gastric lesions model in rats. MATERIAL AND METHODS: After randomly distribution into five group (G1 - G5, n = 8 animals/group), male Wistar rats were daily treated with ASA solution (200 mg/kg, 5 ml/kg, G2 - G5) or potable water (Satellite group, G1) during 14 days. From 8th to 14th experimental day, rats in G3 - G5 groups were orally treated with CAE (50, 100 and 500 mg/kg, 5 ml/kg, respectively). Body weight was measured on 0, 7th and 14th day. On the 14th experimental day, all surviving animals were euthanized for macroscopic evaluation of the inner organs and stomach removal. After weighting, each stomach was properly prepared for biochemical analysis [myeloperoxidase activity (MPO), reduced glutathione analysis (GSH), IL-1ß, CXCL2/MIP-2, TNF-α and IL-10 levels]. RESULTS: At the most efficient dose (100 mg/kg, p.o.), CAE-treated animals showed a slight improvement in the macroscopic aspect of gastric mucosa associated with significant (p < 0.05) reduced levels of IL-1ß, CXCL2/MIP-2, and MPO activity besides increased levels of GSH (partially), and IL-10 in stomach tissues. CONCLUSIONS: The present study demonstrated that the carotenoid and anacardic acids-enriched extract obtained from cashew apple pomace is a promising raw material for the development of herbal medicine and/or functional food supplements for the adjuvant treatment of NSAIDs-induced gastric ulcers.

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.

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.

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.

Anacardic acid from brazilian cashew nut trees reduces dentine erosion.

The aim of this study was to analyze the effect of solutions containing saturated anacardic acid (AA) on dentine erosion in vitro. AA was chemically isolated from natural cashew nutshell liquid obtained by continuous extraction in a Soxhlet extractor and was fully saturated by catalytic hydrogenation. Matrix metalloproteinase 2 (MMP-2) activity, when exposed to buffers containing 100 µmol/l AA, was analyzed using zymography. Bovine root samples were subjected to erosive demineralization (Sprite Zero™, 4 × 90 s/day) and remineralization with artificial saliva between the erosive cycles for 5 days. The samples were treated as follows, after the first and the last acid exposure (1 min; n = 12/group): (1) 100 µmol/l epigallocatechin-3-gallate (EGCG) (positive control); (2) 0.05% NaF; (3) 100 µmol/l saturated AA; (4) saturated AA and EGCG; (5) saturated AA, EGCG and NaF; (6) untreated (negative control). Dentine erosion was measured using a contact profilometer. Two dentine samples from each group were analyzed using scanning electron microscopy. Saturated AA reduced the activity of MMP-2. ANOVA and Tukey's test revealed that all treatments significantly reduced dentine loss compared to the negative control (6.03 ± 0.98 µm). Solutions containing saturated AA (1.97 ± 1.02 µm) showed the greatest reduction in dentine erosion compared to the NaF (3.93 ± 1.54 µm) and EGCG (3.79 ± 0.83 µm) solutions. Therefore, it may be concluded that AA significantly reduces dentine erosion in vitro, possibly by acting as an MMP-2 inhibitor.

[ALS disease modeling and drug screening using patient-specific iPS cells].

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder in which motor neuron (MN) loss in the spinal cord leads to progressive paralysis and death. Cytosolic aggregations in ALS MNs are composed of Tar DNA-binding protein-43 (TDP-43). Genetic analysis has identified more than twenty mutations of TDP-43 in ALS cases. Although accumulating evidence provides several hypotheses of disease mechanism, it is still needed to discover effective cure for ALS. We aimed to reveal cellular phenotypes in ALS MNs for identifying a drug-screening target for ALS using patient-specific induced pluripotent stem cells (iPSCs). To generate patient-specific iPSCs, dermal fibroblasts were obtained by biopsy from ALS patients carrying mutant TDP-43. The fibroblasts were reprogrammed by retrovirus or episomal vectors. Disease-specific iPSCs were differentiated into MNs expressing HB9 and SMI-32. Despite short culture period, ALS MNs recapitulated several disease phenotypes including detergent-insoluble TDP-43, shortened neurites and cellular vulnerability that observed in patient and animal models. Anacardic acid treatment reverted those phenotypes. Disease-specific iPSCs might provide a first step for drug-screening platform for ALS using patient-specific iPSCs.

Protective effect of anacardic acids from cashew (Anacardium occidentale) on ethanol-induced gastric damage in mice.

Cashew nut-shell liquid and the contained anacardic acids (AAs) have been shown to possess antioxidant, lipoxygenase inhibitory, anti-Helicobacter pylori and antitumor properties. Despite these known effects, hitherto there were no published reports on their likely gastroprotective effects. The present study was designed to verify whether AAs afford gastroprotection against the ethanol-induced gastric damage and to examine the underlying mechanism(s). Gastric damage was induced by intragastric administration of 0.2mL of ethanol (96%). Mice in groups were pretreated orally with AAs (10, 30 and 100mg/kg), misoprostol (50 microg/kg), or vehicle (2% Tween 80 in saline, 10mL/kg), 45min before ethanol administration. They were sacrificed 30min later, the stomachs excised, and the mucosal lesion area (mm(2)) measured by planimetry. Gastroprotection was assessed in relation to inhibition of gastric lesion area. To study the gastroprotective mechanism(s), its relations to capsaicin-sensitive fibers, endogenous prostaglandins, nitric oxide and ATP-sensitive potassium channels were analysed. Treatments effects on ethanol-associated oxidative stress markers GSH, MDA, catalase, SOD, and total nitrate/nitrite levels as an index of NO were measured in gastric tissue. Besides, the effects of AAs on gastric secretory volume and total acidity were analysed in 4-h pylorus-ligated rat. AAs afforded a dose-related gastroprotection against the ethanol damage and further prevented the ethanol-induced changes in the levels of GSH, MDA, catalase, SOD and nitrate/nitrite. However, they failed to modify the gastric secretion or the total acidity. It was observed that the gastroprotection by AAs was greatly reduced in animals pretreated with capsazepine, indomethacin, l-NAME or glibenclamide. These results suggest that AAs afford gastroprotection principally through an antioxidant mechanism. Other complementary mechanisms include the activation of capsaicin-sensitive gastric afferents, stimulation of endogenous prostaglandins and nitric oxide, and opening of K(+)(ATP) channels. These combined effects are likely to be accompanied by an increase in gastric microcirculation.