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With the increase of neglected diseases such as leishmaniasis and Chagas disease, there was a need for the search for new therapeutic alternatives that reduce the harm caused by medicine available for treatment. Thus, this study was performed to investigate the antiparasitic activity of the essential oil from the fruits of Piper tuberculatum Jacq, against lines of Leishmania braziliensis (MHOM/CO/88/UA301), Leishmania infantum (MHOM/ES/92/BCN83) and Trypanosoma cruzi (LC-B5 clone). Before running protocols, an analysis of the chemical composition of essential oil was conducted, which presented monoterpenes and sesquiterpenes. As major constituents, β-pinene and α-pinene were identified. Regarding to antiparasitic activity, the essential oil had an EC50 values of 133.97 µg/mL and 143.59 µg/mL against variations promastigotes of L. infantum and L. braziliensis, respectively. As for trypanocidal activity, the oil showed EC50 value of 140.31 µg/mL against epimastigote form of T. cruzi. Moreover, it showed moderate cytotoxicity in fibroblasts with LC50 value of 204.71 µg/mL. The observed effect may be related to the presence of terpenes contained in the essential oil, since it has its antiparasitic activity proven in the literature. [ABSTRACT FROM AUTHOR]

Pain is an unpleasant sensation associated with a wide range of injuries and diseases, and affects approximately 20% of adults in the world. The discovery of new and more effective drugs that can relieve pain is an important research goal in both the pharmaceutical industry and academia. This review describes studies involving antinociceptive activity of essential oils from 31 plant species. Botanical aspects of aromatic plants, mechanisms of action in pain models and chemical composition profiles of the essential oils are discussed. The data obtained in these studies demonstrate the analgesic potential of this group of natural products for therapeutic purposes. [ABSTRACT FROM AUTHOR]

In the present study, we evaluated omega-3 polyunsaturated fatty acid (PUFA) (consisting of 20:5n-3 and 22:6n-3) properties on inflammation and nociception. Among the in vivo tests, writhing, formalin, and hot plate tests were conducted in mice, and carrageenan-induced paw edema, peritonitis, and Hargreaves tests were performed in rats. Following the carrageenan- induced edema, immunohistochemistry for tumor necrosis factor-α (TNF-α) was also carried out. We found that omega-3 PUFA treatment significantly decreased acetic acid-induced abdominal contortions as well as the first and second phases of the formalin test, which were reversed by naloxone. The carrageenan-induced rat paw edema was significantly reduced, along with neutrophil migration to the peritoneal cavity in the omega-3 PUFA treatment. In addition, there was a decrease in TNF-α immunostained cells in the inflamed paw with the omega-3 treatment compared with no omega-3. Withdrawal threshold in response to the thermal stimulation was significantly increased by the omega-3 treatment in the Hargreaves and hot plate tests. The in vitro studies (myeloperoxidase, lactate dehydrogenase, MTT cell viability and lipid peroxidation assays) were performed in human neutrophils. These studies showed that omega-3 treatment significantly decreased myeloperoxidase release, presented no cytotoxicity, and did not alter lipid peroxidatlon. Our study suggests that omega-3 PUFA anti-inflammatory and antinociceptive actions may involve inhibition of cyclooxygenases and microglial activation, leading to a reduced release of proinflammatory cytokines such as TNF-α, among other factors. The omega-3 PUFAs are potential candidates used alone or in combination with conventional nonsteroidal anti- inflammatory drugs, for the treatment of diseases where inflammation plays an important role. [ABSTRACT FROM AUTHOR]

Pain is characterized by the unpleasant sensory and emotional sensation associated with actual or potential tissue damage, whereas nociception refers to the mechanism by which noxious stimuli are transmitted from the periphery to the CNS. The main drugs used to treat pain are nonsteroidal anti-inflammatory drugs (NSAIDs) and opioid analgesics, which have side effects that limit their use. Therefore, in the search for new drugs with potential antinociceptive effects, essential oils have been studied, whose constituents (monoterpenes) are emerging as a new therapeutic possibility. Among them, linalool and its metabolites stand out. The present study aims to investigate the antinociceptive potential of linalool and its metabolites through a screening using an in silico approach. Molecular docking was used to evaluate possible interactions with important targets involved in antinociceptive activity, such as α 2 -adrenergic, GABAergic, muscarinic, opioid, adenosinergic, transient potential, and glutamatergic receptors. The compounds in the investigated series obtained negative energies for all enzymes, representing satisfactory interactions with the targets and highlighting the multi-target potential of the L4 metabolite. Linalool and its metabolites have a high likelihood of modulatory activity against the targets involved in nociception and are potential candidates for future drugs., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Annona muricata Linnaeus (Annonaceae), popularly known as graviola , is used in folk medicine as both sedative and anticonvulsant. This study correlates the neurochemical profile with the behavioral effects of the hydroalcoholic extract from the leaves of Annona muricata (HLEAM) in mice, proposing to elucidate their mechanism of action on the central nervous system. Flavonoids and phenolic compounds were identified and quantified by High Performance Liquid Chromatography (HPLC) method. The acute toxicity (median lethal dose - LD 50 ) was determined by probitos method using the percentage of mortality based on the Hippocratic screen. HLEAM (25, 50 and 100 mg/kg) was tested, intraperitoneally (i.p.), in models of sedation, anxiety, motor coordination, and seizures. The endogenous levels of dopamine, norepinephrine and DOPAC were assayed by reverse-phase HPLC with electrochemical detection. The HPLC analysis of the extract revealed the presence of flavonoids (quercetin, isoquercitrin, quercitrin, rutin, and kaempferol) and phenolics acids (gallic, chlorogenic, ellagic and caffeic acids). The LD 50 was 1091.7 mg/kg and Hippocratic screening indicated central nervous system depressant effect. HLEAM presented sedative effects at doses of 25, 50, and 100 mg/kg, as well as anxiolytic and anticonvulsant effects at a dose of 100 mg/kg. In addition, these effects were partially reversed by flumazenil. The monoamines analysis by HPLC showed that HLEAM decreased the level of norepinefrine and dopamine in the mouse brain striatum. Thus, the results indicate a possible interaction of HLEAM with the GABAergic and monoaminergic systems, adding medicinal value to the popular use of the plant for the treatment of behavioral and neurological disorders.