Chemical characterization and pharmacological assessment of polysaccharide free, standardized cashew gum extract (Anacardium occidentale L.).

ETHNOPHARMACOLOGICAL RELEVANCE: The cashew gum (Anacardium occidentale L.) is used in traditional Brazilian medicine in the treatment of inflammatory conditions, asthma, diabetes, and gastrointestinal disturbances. AIM OF THE STUDY: In the present study, we aimed at forming a chemical characterization and investigation of the antinociceptive and anti-inflammatory activities of the aqueous extract of cashew gum without the presence of polysaccharides in its composition (CGE). MATERIALS AND METHODS: The CGE was obtained after the precipitation and removal of polysaccharides through the use of acetone. After, the acetone was removed by rotaevaporation, and the concentrated extract was lyophilized. The chemical characterization of CGE was performed by liquid chromatography mass spectrometry (LC-MS) and tandem mass spectrometry (MS/MS) analyses. Mice were used for the evaluation of the antinociceptive and anti-inflammatory activities. CGE was analyzed via the Irwin test, acetic acid-induced writhing test, formalin-induced pain test, and carrageenan-induced paw edema test. The motor activity or probable sedation was verified through the chimney, open-field, and sodium pentobarbital-induced sleep tests. We investigated if the analgesic and anti-inflammatory effects of CGE depend of reduction in PGE2 levels, were performed the carrageenan or PGE2-induced hyperalgesia tests. RESULTS: The chemical characterization of CGE showed the presence of anacardic acids as the predominant phytoconstituents. The treatment with CGE (75, 150, and 300mg/kg, p.o.) inhibited the number of writhing in a dose-dependent manner. With an intermediate dose, CGE did not cause motor impairment with the chimney test or alterations in either the open-field or sodium pentobarbital-induced sleep. In the formalin-induced pain test, CGE (150mg/kg, p.o.) produced an antinociceptive effect only in the first phase of the test, suggesting anti-inflammatory activity. With the same dosage, CGE also reduced the carrageenan-induced paw edema at all hours of the test, confirming its anti-inflammatory effect. Furthermore, CGE (150mg/kg, p.o.) presented an antihyperalgic effect at all hours of the carrageenan-induced hyperalgesia test. However, this dose of CGE was not able to reduce the hyperalgesia induced by PGE2, suggesting that the anti-inflammatory effect of this extract depends on the reduction in the PGE2 levels. CONCLUSION: The anacardic acids are the predominant phytoconstituents identified in the CGE. The action mechanisms of CGE suggest the reduction in the PGE2 levels. These findings support the use of cashew gum in popular medicine and demonstrate that part of its antinociceptive and anti-inflammatory effects should also be attributed to the presence of anacardic acids in its composition, independent of the presence of polysaccharides.

Antinociceptive, anti-inflammatory and anxiolytic-like effects of the ethanolic extract, fractions and Hibalactone isolated from Hydrocotyle umbellata L. (Acariçoba) - Araliaceae.

Hydrocotyle umbellata Linn. (Araliaceae) is specie used in the treatment of inflammatory diseases. Crude extract (E-HU) was prepared from H. umbellata subterraneous parts and fractionated by liquid-liquid partition, resulting hexane fraction (HF-HU), dichloromethane fraction (DF-HU), ethyl acetate fraction (EAF-HU) and aqueous fraction (AF-HU). The hibalactone (HU-1) was isolated from the DF-HU and its structure was elucidated by 1H NMR and 13C NMR Spectroscopy, mass spectrometry and crystallographic x-ray analysis. The formalin-induced nociception was used to evaluate antinociceptive activity; carrageenan-induced edema and pleurisy tests to evaluate anti-inflammatory activity and light-dark box to evaluate anxiolytic-like activity in mice. The acute oral treatments with E-HU (1000mg/kg), DF-HU (150mg/kg), EAF-HU (400mg/kg) and HU-1 (33mg/kg) decreased the licking time in both phases of the formalin test. In the carrageenan-induced inflammation models, the treatment with the same doses of E-HU, DF-HU, EAF-HU and HU-1 reduced the paw edema formation and leukocytes account into pleural cavity. In silico findings suggest that hibalactone present anti-inflammatory activity by interacting with the enzymes 5-lipoxygenase and cyclooxygenase-2. In the light dark box, the treatments with DF-HU, EAF-HU and HU-1 revealed an anxiolytic like effect. Thus, the E-HU and fractions of H. umbellata showed antinociceptive, anti-inflammatory and anxiolytic like activities, as also hibalactone, a possible phytoconstituent responsible for the biological effects of this specie.

Efficient electrochemical remediation of microcystin-LR in tap water using designer TiO2@carbon electrodes.

Microcystin-leucine arginine (MC-LR) is the most abundant and toxic secondary metabolite produced by freshwater cyanobacteria. This toxin has a high potential hazard health due to potential interactions with liver, kidney and the nervous system. The aim of this work was the design of a simple and environmentally friendly electrochemical system based on highly efficient nanostructured electrodes for the removal of MC-LR in tap water. Titania nanoparticles were deposited on carbon (graphite) under a simple and efficient microwave assisted approach for the design of the electrode, further utilized in the electrochemical remediation assays. Parameters including the applied voltage, time of removal and pH (natural tap water or alkaline condition) were investigated in the process, with results pointing to a high removal efficiency for MC-LR (60% in tap water and 90% in alkaline media experiments, under optimized conditions).

New pyrazole derivative 5-[1-(4-fluorophenyl)-1H-pyrazol-4-yl]-2H-tetrazole: synthesis and assessment of some biological activities.

The molecular modification and synthesis of compounds is vital to discovering drugs with desirable pharmacological and toxicity profiles. In response to pyrazole compounds' antipyretic, analgesic, and anti-inflammatory effects, this study sought to evaluate the analgesic, anti-inflammatory, and vasorelaxant effects, as well as the mechanisms of action, of a new pyrazole derivative, 5-[1-(4-fluorophenyl)-1H-pyrazol-4-yl]-2H-tetrazole. During the acetic acid-induced abdominal writhing test, treatments with 5-[1-(4-fluorophenyl)-1H-pyrazol-4-yl]-2H-tetrazole reduced abdominal writhing, while during the formalin test, 5-[1-(4-fluorophenyl)-1H-pyrazol-4-yl]-2H-tetrazole reduced licking times in response to both neurogenic pain and inflammatory pain, all without demonstrating any antinociceptive effects, as revealed during the tail flick test. 5-[1-(4-fluorophenyl)-1H-pyrazol-4-yl]-2H-tetrazole also reduced carrageenan-induced paw edema and cell migration during the carrageenan-induced pleurisy test. As demonstrated by the model of the isolated organ, 5-[1-(4-fluorophenyl)-1H-pyrazol-4-yl]-2H-tetrazole exhibits a vasorelaxant effect attenuated by Nω-nitro-l-arginine methyl ester, 1H-[1,2,4]oxadiazolo[4,3-alpha]quinoxalin-1-one, tetraethylammonium or glibenclamide. 5-[1-(4-fluorophenyl)-1H-pyrazol-4-yl]-2H-tetrazole also blocked CaCl2 -induced contraction in a dose-dependent manner. Suggesting a safe toxicity profile, 5-[1-(4-fluorophenyl)-1H-pyrazol-4-yl]-2H-tetrazole reduced the viability of 3T3 cells at higher concentrations and was orally tolerated, despite signs of toxicity in doses of 2000 mg/kg. Lastly, the compounds' analgesic activity might be attributed to the involvement of the NO/cGMP pathway and K+ channels observed in the vasorelaxant effect.