RESUMO
The activation of the human cannabinoid receptor type II (CB2R) is known to mediate analgesic and anti-inflammatory processes without the central adverse effects related to cannabinoid receptor type I (CB1R). In this work we describe the synthesis and evaluation of a novel series of N-aryl-2-pyridone-3-carboxamide derivatives tested as human cannabinoid receptor type II (CB2R) agonists. Different cycloalkanes linked to the N-aryl pyridone by an amide group displayed CB2R agonist activity as determined by intracellular [cAMP] levels. The most promising compound 8d exhibited a non-toxic profile and similar potency (EC50 = 112 nM) to endogenous agonists Anandamide (AEA) and 2-Arachidonoylglycerol (2-AG) providing new information for the development of small molecules activating CB2R. Molecular docking studies showed a binding pose consistent with two structurally different agonists WIN-55212-2 and AM12033 and suggested structural requirements on the pyridone substituents that can satisfy the orthosteric pocket and induce an agonist response. Our results provide additional evidence to support the 2-pyridone ring as a suitable scaffold for the design of CB2R agonists and represent a starting point for further optimization and development of novel compounds for the treatment of pain and inflammation.
Assuntos
Agonistas de Receptores de Canabinoides/química , Agonistas de Receptores de Canabinoides/farmacologia , Piridonas/química , Receptor CB2 de Canabinoide/agonistas , Animais , Ácidos Araquidônicos/química , Ácidos Araquidônicos/farmacologia , Benzoxazinas/química , Benzoxazinas/farmacologia , Sítios de Ligação , Células CHO , Agonistas de Receptores de Canabinoides/síntese química , Sobrevivência Celular/efeitos dos fármacos , Cricetulus , AMP Cíclico/metabolismo , Avaliação Pré-Clínica de Medicamentos , Endocanabinoides/química , Endocanabinoides/farmacologia , Glicerídeos/química , Glicerídeos/farmacologia , Células HL-60 , Células Hep G2 , Humanos , Simulação de Acoplamento Molecular , Morfolinas/química , Morfolinas/farmacologia , Naftalenos/química , Naftalenos/farmacologia , Alcamidas Poli-Insaturadas/química , Alcamidas Poli-Insaturadas/farmacologia , Piridonas/farmacologia , Receptor CB2 de Canabinoide/química , Receptor CB2 de Canabinoide/genética , Receptor CB2 de Canabinoide/metabolismo , Relação Estrutura-AtividadeRESUMO
Tardive dyskinesia (TD) is a side effect associated with the long-term use of certain antipsychotics. Considering the modulatory role of the endocannabinoid system upon dopaminergic neurotransmission, the present study tested the hypothesis that increasing endocannabinoid (anandamide and 2-arachidonoylglycerol) levels attenuates haloperidol-induced TD (vacuous chewing movements, VCMs) in male Wistar rats. The animals received administration of chronic haloperidol (38 mg/kg; 29 days) followed by acute FAAH (URB597, 0.1-0.5 mg/kg) or MAGL (JZL184, 1-10 mg/kg) inhibitors before VCM quantification. The underlying mechanisms were evaluated by pre-treatments with a CB1 receptor antagonist (AM251, 1 mg/kg) or a TRPV1 channel blocker (SB366791, 1 mg/kg). Moreover, CB1 receptor expression was evaluated in the striatum of high-VCM animals. As expected, haloperidol induced VCMs only in a subset of rats. Either FAAH or MAGL inhibition reduced VCMs. These effects were prevented by CB1 receptor antagonism, but not by TRPV1 blockage. Remarkably, CB1 receptor expression was increased high-VCM rats, with a positive correlation between the levels of CB1 expression and the number of VCMs. In conclusion, increasing endocannabinoid levels results in CB1 receptor-mediated protection against haloperidol-induced TD in rats. The increased CB1 receptor expression after chronic haloperidol treatment suggests a counter-regulatory protective mechanism.
Assuntos
Agonistas de Receptores de Canabinoides/farmacologia , Discinesia Induzida por Medicamentos/tratamento farmacológico , Endocanabinoides/metabolismo , Haloperidol/efeitos adversos , Animais , Antipsicóticos/efeitos adversos , Ácidos Araquidônicos/farmacologia , Antagonistas de Receptores de Canabinoides/farmacologia , Corpo Estriado/efeitos dos fármacos , Modelos Animais de Doenças , Discinesia Induzida por Medicamentos/metabolismo , Endocanabinoides/farmacologia , Glicerídeos/farmacologia , Masculino , Mastigação/efeitos dos fármacos , Alcamidas Poli-Insaturadas/farmacologia , Ratos , Ratos Wistar , Receptor CB1 de Canabinoide/metabolismo , Canais de Cátion TRPV/metabolismo , Discinesia Tardia/tratamento farmacológico , Discinesia Tardia/metabolismoRESUMO
The insect immune system includes several mechanisms responsible for defending against pathogens, parasites, and parasitoids. Some botanical insecticides, such as Azadirachta indica oil, cause changes in the immune system of various insect species. Spodoptera frugiperda is an important agricultural pest; thus, knowledge about the effect of neem oil on the immune system of this species can assist in its management. This study aimed to evaluate the effect of A. indica oil on the immune system of S. frugiperda. Caterpillars (2-3 mg) were placed individually in containers (50 ml) with approximately 10 g of diet, containing 125, 250, and 500 ppm of neem oil with propanone; the control group received only the propanone diet. In four experiments, the total number of hemocytes, the phagocytic activity, the activity of lysozyme-like enzymes, and phenoloxidase activity were measured in caterpillars at the end of the sixth instar. The total number of hemocytes in insects exposed to neem oil was 21% lower than in the control group. The percentage of cells that phagocyted the latex beads was similar among the caterpillars that ingested the different concentrations. The mean diameter of cell lysis halos was reduced only at concentrations of 125 and 250 ppm. Absorbance did not differ between treatments. Knowing that this oil reduces the number of circulation cells and the activity of lysozyme-like enzymes is of great importance to design control strategies, once the neem oil could be added to other biological agents for mortality reducing the chances of this insect surviving in the environment.
Assuntos
Azadirachta/química , Glicerídeos/farmacologia , Inseticidas/farmacologia , Larva/efeitos dos fármacos , Spodoptera/efeitos dos fármacos , Terpenos/farmacologia , Animais , Sistema Imunitário/efeitos dos fármacos , Larva/imunologia , Spodoptera/imunologiaRESUMO
The brown dog tick (Rhipicephalus sanguineus) is prevalent on canids in Trinidad. It is directly (by causing anaemia) and indirectly (by acting as a vector of tick-borne pathogens) responsible for morbidity and mortalities in the canine population. The most commonly used commercial acaricides available to pet owners in Trinidad are amitraz and fipronil. Often, these acaricides may be abused and misused in a desperate attempt to rid pets of ticks. The objective of this study was to compare the efficacy of amitraz and fipronil with the herbal alternative, neem (Azadirachta indica). Triplicate in vitro trials utilizing the Larval Packet Test (LPT) were conducted using three concentrations (low, recommended and high) of fipronil (0.025%, 0.05% and 0.1%), amitraz (0.01%, 0.02% and 1%), neem oil (10%, 20% and 40%) and neem leaf extract (0.25%, 0.5% and 2%) for each trial. Statistical analysis using the mixed-effect Poisson regression analysis indicated that there was a significant difference (p < .05) in the survival of ticks pre-treatment versus post-treatment with amitraz, fipronil and all controls when compared to the neem oil. Fipronil and amitraz caused ≥99% mortality for all concentrations used in this study. Mortalities for neem oil and neem leaf extract ranged from 72.7% to 82% and 38% to 95.3%, respectively, with the greatest percentage of mortalities occurring at the lower concentrations. Neem oil and neem leaf extract can be used as alternative acaricides, and however, they are less efficacious against the brown dog tick than amitraz and fipronil.
Assuntos
Acaricidas/farmacologia , Azadirachta/química , Glicerídeos/farmacologia , Pirazóis/farmacologia , Rhipicephalus sanguineus/efeitos dos fármacos , Terpenos/farmacologia , Infestações por Carrapato/veterinária , Toluidinas/farmacologia , Animais , Cães , Feminino , Geografia , Larva , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/mortalidade , Infestações por Carrapato/parasitologia , Trinidad e Tobago/epidemiologiaRESUMO
Aspergillus carbonarius is a saprobic filamentous fungus, food spoiling fungus and a producer of ochratoxin A (OTA) mycotoxin. In this study, the in vitro antifungal activity of neem oil (0.12% p/p of azadirachtin) was evaluated against the growth of six strains of A. carbonarius and the production of OTA. Four different concentrations of neem oil were tested in addition to three incubation times. Only the concentration of 0.3% of neem oil inhibited more than 95% of the strain's growth (97.6% ± 0.5%), while the use of 0.5% and 1.0% of neem oil showed lower antifungal activity, 40.2% ± 3.1 and 64.7% ± 1.1, respectively. There was a complete inhibition of OTA production with 0.1% and 0.3% neem oil in the four strains isolated in the laboratory from grapes. The present study shows that neem essential oil can be further evaluated as an auxiliary method for the reduction of mycelial growth and OTA production.
Assuntos
Antifúngicos/farmacologia , Aspergillus/efeitos dos fármacos , Glicerídeos/farmacologia , Ocratoxinas/metabolismo , Terpenos/farmacologia , Aspergillus/crescimento & desenvolvimento , Aspergillus/metabolismoRESUMO
BACKGROUND: The entomopathogenic fungus Metarhizium anisopliae is a candidate for the integrated management of the disease vector mosquito Aedes aegypti. Metarhizium anisopliae is pathogenic and virulent against Ae. aegypti larvae; however, its half-life is short without employing adjuvants. Here, we investigated the use of neem oil to increase virulence and persistence of the fungus under laboratory and simulated field conditions. METHODS: Neem was mixed with M. anisopliae and added to recipients. Larvae were then placed in recipients at 5-day intervals for up to 50 days. Survival rates were evaluated 7 days after exposing larvae to each treatment. The effect of neem on conidial germination following exposure to ultraviolet radiation was evaluated under laboratory conditions. Statistical tests were carried out using ANOVA and regression analysis. RESULTS: Laboratory bioassays showed that the fungus alone reduced survival to 30% when larvae were exposed to the treatment as soon as the suspension had been prepared (time zero). A mixture of fungus + neem resulted in 11% survival at time zero. The combination of fungus + neem significantly reduced larval survival rates even when suspensions had been maintained for up to 45 days before adding larvae. For simulated-field experiments 1% neem was used, even though this concentration is insecticidal, resulting in 20% survival at time zero. However, this toxic effect was reduced over time. When used alone under simulated-field conditions the fungus rapidly lost virulence. The formulation fungus + neem effectively maintained fungal virulence, with larval survival rates significantly reduced for up to 45 days after preparation of the suspensions. The effective half-life of the fungus or neem when used separately was 6 and 13 days, respectively. The half-life of fungus formulated in 1% neem was 34 days. Conidia suspended in neem maintained high levels of germination even following a 2-h exposure to ultraviolet radiation. CONCLUSIONS: A combination of the entomopathogenic fungus M. anisopliae with neem oil effectively increases the half-life and virulence of the fungus when tested against Ae. aegypti larvae, even under simulated field conditions. Neem oil also protected the fungus from the damaging effects of ultraviolet radiation.
Assuntos
Aedes/microbiologia , Glicerídeos/farmacologia , Metarhizium/efeitos dos fármacos , Controle de Mosquitos/métodos , Terpenos/farmacologia , Animais , Metarhizium/patogenicidade , Metarhizium/fisiologia , Virulência/efeitos dos fármacosRESUMO
Mast cells (MCs) contribute to the control of local inflammatory reactions and become hyporesponsive after prolonged TLR4 activation by bacterial LPS. The molecular mechanisms involved in endotoxin tolerance (ET) induction in MCs are not fully understood. In this study, we demonstrate that the endocannabinoid 2-arachidonoylglycerol (2-AG) and its receptor, cannabinoid receptor 2 (CB2), play a role in the establishment of ET in bone marrow-derived MCs from C57BL/6J mice. We found that CB2 antagonism prevented the development of ET and that bone marrow-derived MCs produce 2-AG in a TLR4-dependent fashion. Exogenous 2-AG induced ET similarly to LPS, blocking the phosphorylation of IKK and the p65 subunit of NF-κB and inducing the synthesis of molecular markers of ET. LPS caused CB2 receptor trafficking in Rab11-, Rab7-, and Lamp2-positive vesicles, indicating recycling and degradation of the receptor. 2-AG also prevented LPS-induced TNF secretion in vivo, in a MC-dependent model of endotoxemia, demonstrating that TLR4 engagement leads to 2-AG secretion, which contributes to the negative control of MCs activation. Our study uncovers a functional role for the endocannabinoid system in the inhibition of MC-dependent innate immune responses in vivo.
Assuntos
Ácidos Araquidônicos/farmacologia , Endocanabinoides/farmacologia , Glicerídeos/farmacologia , Tolerância Imunológica/efeitos dos fármacos , Lipopolissacarídeos/toxicidade , Mastócitos/imunologia , Receptor CB2 de Canabinoide/imunologia , Receptor 4 Toll-Like/imunologia , Animais , Tolerância Imunológica/imunologia , Proteína 2 de Membrana Associada ao Lisossomo/genética , Proteína 2 de Membrana Associada ao Lisossomo/imunologia , Camundongos , Camundongos Knockout , Transporte Proteico/efeitos dos fármacos , Transporte Proteico/genética , Transporte Proteico/imunologia , Receptor CB2 de Canabinoide/genética , Receptor 4 Toll-Like/genética , Fator de Transcrição RelA/genética , Fator de Transcrição RelA/imunologia , Proteínas rab de Ligação ao GTP/genética , Proteínas rab de Ligação ao GTP/imunologia , proteínas de unión al GTP Rab7RESUMO
Novel biological control methods and integrated pest management strategies are basic requirements for the development of sustainable agriculture. As a result, there is a growing demand for research on the use of plant extracts and natural enemies such as the green lacewing, Ceraeochrysa claveri, as natural pest control methods. Studies have shown that although natural compounds such as neem oil (Azadirachta indica) are effective as pest control strategies, they also cause sublethal effects on nontarget insects, such as C. claveri. The aim of this study was to examine the effects of neem oil on C. claveri testes. C. claveri larvae were fed Diatraea saccharalis eggs, which were pretreated with 0.5%, 1%, and 2% neem oil. Testes were collected from larvae, pupae, and adults and analyzed using light and electron (transmission and scanning) microscopy. Changes in cellular stress and possible cell death were also determined by TUNEL assay and the marker HSP-70. The results showed that neem oil affects the organization and distribution of cysts in the testes and the normal sequence of cyst development, causing a delay in spermatogenesis in the testes of treated insects. Tests for cellular stress and DNA fragmentation indicated there was no cellular alteration in the treated groups. Although neem oil does not induce cell death or changes in HSP-70 expression, this biopesticide negatively impacts the process of spermatogenesis and could decrease the perpetuation of this species in the agroecosystem, indicating that the use of neem oil in association with green lacewings as a biological control should be carefully evaluated.
Assuntos
Glicerídeos/farmacologia , Insetos/fisiologia , Comportamento Predatório , Espermatogênese/efeitos dos fármacos , Terpenos/farmacologia , Animais , Insetos/efeitos dos fármacos , Insetos/ultraestrutura , Larva/efeitos dos fármacos , Larva/ultraestrutura , Masculino , Comportamento Predatório/efeitos dos fármacos , Pupa/efeitos dos fármacos , Pupa/ultraestrutura , Testículo/efeitos dos fármacos , Testículo/ultraestruturaRESUMO
The aim of this work was to evaluate the compatibility of (+)-catechin (CA) and excipients commonly used to prepare micro and nanoemulsions using thermal analysis along with complementary assays. Lipid compounds labrasol, plurol and ethyl oleate were combined with CA according to a simplex centroid mixture design and possible interactions between them were determined. Differential scanning calorimetry and thermogravimetric analyses were carried out together with Fourier transform infrared spectroscopy (FTIR) and morphologic characterization of the samples. A quantitative evaluation of thermal events involved in CA melting peak and initial sample decomposition temperature were performed. FTIR evaluation suggested an initial decomposition of CA mixtures exposed to a thermal aging depending on their composition corroborated by the darkening of these samples. The multiple regression analysis considering the thermal data revealed a thermal interaction compromising CA stability in multicomponent samples. Mixtures containing ethyl oleate exhibited a negative synergic action of this fatty acid with the others two lipid compounds (negative coefficients for two-factor and three-factor interaction terms). Indeed, samples decomposition was anticipated by at least 10°C in the case of ternary and quaternary mixtures containing ethyl oleate. In conclusion, CA formulations produced with lipid components must have their stability closely monitored and production process involving heating should be avoided, especially in formulations containing ethyl oleate.
Assuntos
Catequina/química , Composição de Medicamentos/métodos , Excipientes/química , Ácidos Oleicos/química , Varredura Diferencial de Calorimetria/métodos , Química Farmacêutica/métodos , Incompatibilidade de Medicamentos , Estabilidade de Medicamentos , Sinergismo Farmacológico , Emulsões , Glicerídeos/química , Glicerídeos/farmacologia , Temperatura Alta/efeitos adversos , Nanopartículas/química , Ácidos Oleicos/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria , Fatores de TempoRESUMO
Several studies searching for methods to control Rhipicephalus sanguineus s.l., (dog tick) infestations have been developed aiming to minimize the damages caused by these ectoparasites to the hosts and the environment, which is harmed by the indiscriminate use of toxic acaricide products. In this scenario, neem oil has been used as a natural alternative against ticks, once this chemical has repellent properties and interferes in the growth regulation of these ectoparasites, inhibiting ecdysis. The present study evaluated the effects of azadirachtin-enriched neem oil on the integument of semi-engorged R.sanguineus s.l., females through morphohistological techniques. The results showed the occurrence of significant morphological and histochemical alterations, mainly in the females exposed to higher concentrations, which demonstrates the dose-dependent action of the chemical. A decrease in the cuticle thickness was observed, as well as a modification in the distribution of the epithelial cells, which displayed pyknotic and fragmented nuclei, and intensely vacuolated cytoplasm, indicating that these cells would be undergoing death processes. These morphological alterations observed in the integument of the females exposed to the azadirachtin-enriched neem oil encourage the use of this chemical as a strategy to control these ectoparasites.