Paeoniflorin mitigates PBC-induced liver fibrosis by repressing NLRP3 formation

ABSTRACT Purpose: To delve into the influence of paeoniflorin (PA) on abating primary biliary cholangitis (PBC)-induced liver fibrosis and its causative role. Methods: Our team allocated the mice to control group, PA group, PBC group and PBC+PA group. We recorded the weight change of mice in each group. We used Masson staining for determining liver fibrosis, immunofluorescence staining for measuring tumor necrosis factor-α (TNF-α) expression, quantitative real-time polymerase chain reaction (qRT-PCR) for assaying related gene expression, as well as Western blot for testing related protein expression. Results: The weight of PBC model mice declined. Twenty-four weeks after modeling, the positive rate of anti-mitochondrial antibody-M2 (AMA-M2) in PBC mice reached 100%. Alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), hydroxyproline (HYP), laminin (LN), procollagen type III (PC III), and malondialdehyde (MDA) contents saliently waxed (p<0.01). Meanwhile, superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) activity patently waned (p<0.01). Liver fibrosis levels were flagrantly higher (p<0.01), and TNF-α, NOD-like receptor protein 3 (NLRP3), caspase-1, interleukin-18 (IL-18), and interleukin-1β (IL-1β) protein or gene expression were manifestly up-regulated (p<0.01). PA could restore the weight of PBC mice, strikingly restrain the positive expression of AMA-M2, and down-regulate serum ALP, ALT, AST, HYP, LN, PC III, MDA in PBC mice (p<0.01). PA could also significantly up-regulate SOD and GSH-px levels (p<0.01), down-regulate IL-1β, IL-18, caspase-1, NLRP3, and TNF-α protein or gene expression in PBC mice (p<0.01) and inhibit liver fibrosis levels (p<0.01). Conclusions: PA can reduce PBC-induced liver fibrosis in mice and may function by curbing the formation of NLRP3.

Anthelmintic activity of nanoencapsulated carvacryl acetate against gastrointestinal nematodes of sheep and its toxicity in rodents / Atividade anti-helmíntica do acetato de carvacrila nanoencapsulado sobre nematoides gastrintestinais de ovinos e toxicidade em roedores

Abstract The objective of this study was to evaluate the efficacy of carvacryl acetate (CVA) and nanoencapsulated CVA (nCVA) on gastrointestinal nematodes of sheep. The CVA was nanoencapsulated with chitosan/gum arabic and the efficacy of nanoencapsulation (EE), yield, zeta potential, nanoparticle morphology and release kinetics at pH 3 and 8 were analyzed. Acute and subchronic toxicity were evaluated in rodents and reduction of egg counts in the faeces (FECRT) of sheep. The sheep were divided into four groups (n = 10): G1, 250 mg/kg CVA; G2, 250 mg/kg nCVA; G3, polymer matrix and G4: 2.5 mg/kg monepantel. EE and nCVA yield were 65% and 57%, respectively. The morphology of the nanoparticles was spherical, size (810.6±286.7 nm), zeta potential in pH 3.2 (+18.3 mV) and the 50% release of CVA at pHs 3 and 8 occurred at 200 and 10 h, respectively. nCVA showed LD50 of 2,609 mg/kg. CVA, nCVA and monepantel reduced the number of eggs per gram of faeces (epg) by 57.7%, 51.1% and 97.7%, respectively. The epg of sheep treated with CVA and nCVA did not differ from the negative control (P>0.05). Nanoencapsulation reduced the toxicity of CVA; however, nCVA and CVA presented similar results in the FECRT.

Resumo O objetivo deste trabalho foi avaliar a eficácia do acetato de carvacrila (ACV) e do ACV nanoencapsulado (nACV) sobre nematóides gastrintestinais de ovinos. O ACV foi nanoencapsulado com quitosana/goma arábica e foi analisada a eficácia de nanoencapsulamento (EE), o rendimento, potencial zeta, morfologia das nanopartículas e cinética de liberação em pH 3 e 8. Foram avaliadas as toxicidades aguda e subcrônica em roedores e a redução da contagem de ovos nas fezes (RCOF) de ovinos. Os ovinos foram divididos em quatro grupos (n = 10): G1, 250 mg/kg ACV; G2, 250 mg/kg de nACV; G3, matriz polimérica e G4: 2,5 mg/kg de monepantel. A EE e o rendimento de nACV foram de 65% e 57%, respectivamente. A morfologia das nanopartículas foi esférica, tamanho (810,6±286,7 nm), potencial zeta no pH 3,2 (+18,3 mV) e a liberação de 50% de CVA nos pHs 3 e 8 ocorreu às 200 e 10 h, respectivamente. nACV apresentou DL50 de 2.609 mg/kg. ACV, nACV e o monepantel reduziram a contagem de ovos por grama de fezes (opg) em 57,7%, 51,1% e 97,7%, respectivamente. A contagem de opg de ovelhas tratadas com ACV e nCVA não diferiu do controle negativo (P>0,05). O nanoencapsulamento reduziu a toxicidade do AVC; no entanto, nACV e ACV apresentaram resultados semelhantes na RCOF.

Perillyl alcohol has antibacterial effects and reduces ROS production in macrophages

Abstract Natural products have emerged as a rich source of bioactive compounds for adjunctive treatments of many infectious and inflammatory conditions, including periodontitis. Among the monoterpenes with significant biological properties, there is the perillyl alcohol (POH), which can be found in several essential oils and has shown immunomodulatory properties in recent studies, which may be interesting in the treatment of non-neoplastic inflammatory disorders. Objective To determine the antibacterial and immune modulatory activities of the POH. Methodology The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the POH for two significant Gram-negative periodontal pathogens were determined by macrodilution and subculture, respectively. Cell proliferation and cytotoxicity in RAW 264.7 macrophages were determined by Trypan Blue and mitochondrial enzymatic activity assay. The modulation of reactive oxygen species (ROS) was analyzed by flow cytometry and expression of TNF and arginase-1 by real-time PCR. Results The POH was effective against P. gingivalis (ATCC 33277) and F. nucleatum (ATCC 25586) with MIC= MBC=1600 μM. No cytotoxicity up to 100 µM was observed on macrophages. The cell proliferation was inhibited from 48 hours at 100 μM (p<0.05) and 250 μM (p<0.01). The POH increased ROS production at both 10 μM and 100 μM (p<0.05) in unstimulated cells. The PMA-induced ROS production was not affected by POH, whereas 100 μM significantly reduced lipopolysaccharide-induced (LPS-induced) ROS. The expression of TNF was not affected by POH in unstimulated cells or in cells polarized to M1 phenotype, whereas both concentrations of POH reduced (p<0.05) the expression of arginase-1 in M2-polarized macrophages. Conclusion The POH has antibacterial activity against periodontal pathogens and reduced proliferation of murine macrophages without significant cytotoxicity at concentrations up to 100 μM. In addition, the POH reduced the LPS-induced ROS and the expression of arginase-1 in M2-polarized macrophages.

Pharmacological effects of different chemotypes of Lippia alba (Mill.) N.E. Brown / Efectos farmacológicos de diferentes quimiotipos de Lippia alba (Mill.) N.E. Brown

The Lippia alba species consists of an aromatic plant used in Brazilian traditional medical practice and in the medical practice of several countries as well. Presenting a wide variability in its essential oil chemical composition, the Lippia alba is classified in chemotypes, or chemical races, according to the major constituents contained in its essential oil. Considering the quali and quantitative distribution of the components in the essential oil affect directly its pharmacological properties, which are presented in the medicinal species, this paper proposes a scientific literature review to correlate both biological and pharmacological properties presented by L. alba according to its chemical constitution.

Lippia alba es una planta aromática utilizada en la medicina tradicional de Brasil y de varios países. Con una gran variabilidad en la composición química de su aceite esencial, se clasifica en quimiotipos, o razas químicas, de acuerdo con los constituyentes mayoritarios presentes en el aceite esencial. Dado que la distribución cualitativa y cuantitativa de los componentes del aceite esencial afecta directamente a las propiedades farmacológicas presentadas por la especie medicinal, este trabajo propone realizar una revisión en la literatura científica para correlacionar las propiedades biológicas y farmacológicas de los quimiotipos presentes en el aceite essencial de la L. alba.

Susceptibility of cariogenic microorganisms to phytoconstituents / Susceptibilidade de microrganismos cariogênicos a fitoconstituintes

Abstract This study aimed to evaluate the in vitro antibacterial activity of the phytochemicals thymol, linalool, and citronellol against Streptococcus mutans, Streptococcus salivarius and Streptococcus oralis. Disk diffusion screening on solid medium and measurement of the diameter of the bacterial growth inhibition halos was the technique utilized. The Minimum Inhibitory Concentration (MIC) of the substances was determined using serial substance dilutions and microdilution technique in Brain Heart Infusion culture medium. After incubation for 24 hours in an oven at 37 °C, plate reading was completed and confirmed by visual method using 2,3,5 triphenyl tetrazolium chloride dye. The Minimum Bactericidal Concentration (MBC) was determined from MIC subcultures. Assays were performed in triplicate, and chlorhexidine was used as a positive control. The diameters in mm of the growth inhibition halos ranged between 7.3 and 10.7 for S. mutans, 7.3 and 10.0 for S. oralis, and 8.2 and 9.8 for S. salivarius. The MIC and MBC values obtained converged, ranging from maximum values in the presence of Linalool (1,250.0 mg/mL, 2,500.0 mg/mL and 2,500.0 mg/mL, respectively, for S. mutans, S. oralis, and S. salivarius); and minimum values with Thymol (312.5 μg/ml, 156.2 μg/mL and 156.2 μg/ml, respectively for S. mutans, S. oralis, and S. salivarius). All the tested phytochemicals displayed antibacterial activity, thus representing substances with potential applications in preventing tooth decay.

Resumo Este estudo objetivou avaliar a atividade antibacteriana in vitro dos fitoquímicos timol, linalol e citronelol sobre Streptococcus mutans, Streptococcus salivaris e Streptococcus oralis. Utilizou-se a técnica de discos de difusão em meio sólido e medição do diâmetro dos halos de inibição. A concentração inibitória mínima (CIM) das substâncias foi determinada utilizando diluições em série das substâncias e técnica de microdiluição em meio de cultura de Brain Heart Infusion. Após incubação durante 24 horas em estufa a 37 °C, a leitura da placa foi confirmada pelo método visual usando o corante 2,3,5 trifenil cloreto de tetrazólio. A concentração bactericida mínima (CBM) foi determinada a partir de subculturas de MIC. Os ensaios foram realizados em triplicata, e clorexidina foi usada como um controle positivo. Os diâmetros dos halos de inibição do crescimento variaram entre 7,3 e 10,7 por S. mutans, 7,3 e 10,0 por S. oralis, e 8,2 e 9,8 para S. salivaris. Os valores de CIM e CBM obtidos variaram de valores máximos na presença de linalol (1.250,0 mg/mL, 2.500.0 mg/mL e 2.500.0 mg/mL, respectivamente, para o S. mutans, S oralis e S. salivaris); a valores mínimos com timol (312,5 μg/ml, 156,2 μg/mL e 156,2 μg/ml, respectivamente para S. mutans, S. oralis e S. salivaris). Todos os fitoquímicos testados apresentaram atividade antibacteriana, representando, assim, substâncias com potencial de aplicações na prevenção da cárie dentária.

Antifungal activity of linalool in cases of Candida spp. isolated from individuals with oral candidiasis / Atividade antifúngica do linalol em casos de Candida spp. isolados de indivíduos com candidíase oral

Abstract This study analyzed the antifungal activity of phytoconstituents from linalool on Candida spp. strains, in vitro, isolated from patients with clinical diagnoses of oral candidiasis associated with the use of a dental prosthesis. Biological samples were collected from 12 patients using complete dentures or removable partial dentures and who presented mucous with diffuse erythematous or stippled features, indicating a clinical diagnosis of candidiasis. To identify fungal colonies of the genus Candida, samples were plated onto CHROMagar Candida®. The antifungal activity of linalool, a monoterpene unsaturated constituent of basil oil, was performed using the broth microdilution technique. Then, the minimum inhibitory concentration (MIC), the two subsequent stronger concentrations and the positive controls were subcultured on Sabouraud Dextrose Agar plates to determine the minimum fungicidal concentration (MFC). The experiments were performed in triplicate and nystatin was used as a positive control in all tests. Diagnoses of oral candidiasis were verified in eight patients (66.6%) and the most prevalent fungal species was Candida albicans (37.5%), followed by Candida krusei (25.0%); and Candida tropicalis (4.2%). The best antifungal activity of linalool was observed on Candida tropicalis (MIC = 500 mg/mL), followed by Candida albicans (MIC = 1.000 mg/mL), and Candida krusei (MIC = 2.000 mg/mL).Under the study conditions and based on the results obtained, it can be concluded that the Candida strains tested were susceptible to linalool.

Resumo Este estudo analisou a atividade antifúngica do fitoconstituinte linalol em cepas de Candida ssp, in vitro, isolados de pacientes com o diagnóstico clínico de candidíase oral associado ao uso de prótese dentária. As amostras biológicas foram coletadas de 12 pacientes portadores de próteses totais ou próteses parciais removíveis e que apresentavam características de mucosa eritematosa difusa ou pontilhadas, indicando um diagnóstico clínico de candidíase. Para identificar colônias de fungos do gênero Candida, as amostras foram semeadas em CHROMagar Candida®. A atividade antifúngica do linalol, um componente insaturado monoterpene de óleo de manjericão, foi realizada através da técnica de microdiluição em caldo. Em seguida, a concentração inibitória mínima (MIC), as duas concentrações consecutivas mais fortes e os controles positivos foram subcultivados em placas de Agar Sabouraud Dextrose para determinar a concentração fungicida mínima (MFC). Os experimentos foram realizados em triplicata e a nistatina foi usada como controle positivo em todos os testes. O diagnóstico de candidíase oral foi comprovado em oito pacientes (66,6%) e as espécies de fungos mais prevalentes foram Candida albicans (37,5%), seguido por Candida krusei (25,0%); e Candida tropicalis (4,2%). A melhor atividade antifúngica do linalol foi observada em Candida tropicalis (MIC = 500 mg/ml), seguido por Candida albicans (CIM = 1,000 mg/mL), e Candida krusei (CIM = 2,000 mg/mL). Sob as condições do estudo e com base nos resultados obtidos, pode-se concluir que as estirpes de Candida testadas foram susceptíveis a linalol.

Chronic treatment with carvacrol improves passive avoidance memory in a rat model of Parkinson's disease / O tratamento com carvacrol melhora a memória de esquiva passiva em um modelo da doença de Parkinson em ratos

ABSTRACT The present study investigated the effects of carvacrol on motor and memory deficits as well as hyperalgesia in the 6-OHDA-lesioned rat model of Parkinson's disease. The animals were subjected to unilateral microinjection of 6-OHDA into the medial forebrain bundle and treated with carvacrol (25, 50 and 100 mg/kg, ip) for six weeks after surgery. The 6-OHDA-lesioned rats showed contralateral rotations towards the lesion side, which was accompanied by learning and memory deficits in a passive avoidance test and a decrease in tail withdrawal latency in a tail flick test at the end of week 6. The results also showed that treatment with carvacrol at a dose of 25 mg/kg ameliorated memory deficits, with no effect on rotations and hyperalgesia in lesioned rats. In conclusion, carvacrol improves memory impairments in rats with Parkinson's disease; therefore, it may serve as an adjunct therapy for the alleviation of memory deficits in Parkinson's disease patients.

RESUMO O presente estudo investigou os efeitos do carvacrol nos déficits motores e de memória, bem como na hiperalgesia, em um modelo da doença de Parkinson (DP) em ratos com lesões 6-OHDA. Os animais foram submetidos a microinjeção unilateral de 6-OHDA no feixe mediano do prosencéfalo e tratados com carvacrol (25, 50 e 100 mg / kg, ip) durante 6 semanas após a cirurgia. Os ratos com lesões 6-OHDA mostraram rotações contralaterais para o lado da lesão, que foram acompanhadas de déficits de aprendizagem e de memória em um teste de evitação passiva, e de uma diminuição da latência de retirada da cauda em um teste de cauda no final da semana 6. Os resultados também mostraram que o tratamento crônico com carvacrol a uma dose de 25 mg / kg aliviou os déficits de memória, sem efeito sobre rotações e hiperalgesia em ratos lesados. Em conclusão, o carvacrol melhora a deficiência de memória em ratos com DP e, portanto, pode servir como uma terapia complementar para aliviar os déficits de memória em pacientes com DP.

Insights into the intracellular mechanisms of citronellal in Candida albicans: implications for reactive oxygen species-mediated necrosis, mitochondrial dysfunction, and DNA damage

Abstract INTRODUCTION Citronellal (Cit) possesses antifungal activity and has possible implications for reactive oxygen species (ROS) generation in Candida albicans. In this study, the effects of Cit on ROS generation and the mechanisms by which Cit exerts anti-Candida effects were examined. METHODS A 2′,7′-dichlorodihydrofluorescein diacetate assay was used to assess oxidative damage. Cell necrosis was determined by flow cytometry after FITC-Annexin V staining. Mitochondrial function was studied based on mitochondrial potential, metabolic activity (MTT assay), and phenotypic susceptibility on a non-fermentable carbon source. Membrane intactness and DNA damage were estimated by a propidium iodide (PI) uptake assay and 4',6-diamidino-2-phenylindole (DAPI) staining. RESULTS ROS generation was enhanced in response to Cit, leading to necrosis (2%). Additional hallmarks of cell death in response to Cit, such as mitochondrial membrane depolarization and DNA damage, were also observed. Cit treatment resulted in dysfunctional mitochondria, as evidenced by poor labeling with the mitochondrial membrane potential-sensitive probe rhodamine B, reduced metabolic activity (61.5%), and inhibited growth on a non-fermentable carbon source. Furthermore, Cit induced DNA damage based on DAPI staining. These phenotypes were reinforced by RT-PCR showing differences in gene expression (30-60%) between control and Cit-treated cells. Finally, PI uptake in the presence of sodium azide confirmed non-intact membranes and suggested that Cit activity is independent of the energy status of the cell. CONCLUSIONS Cit possesses dual anticandidal mechanisms, including membrane-disruptive and oxidative damage. Taken together, our data demonstrated that cit could be used as a prominent antifungal drug.

S-(+)- and R-(-)-linalool: a comparison of the in vitro anti-Aeromonas hydrophila activity and anesthetic properties in fish

ABSTRACT Linalool is the main compound of many essential oils and occurs in two isomeric forms: S-(+)- and R-(-)-linalool. This study aimed to determine if linalool isomers have different antimicrobial and anesthetic properties in fish. For this purpose, these compounds were previously isolated from Lippia alba (Mill.)N. E. Brown and Ocimum americanum L. essential oils. Antimicrobial effects were evaluated through the microdilution test against Aeromonas hydrophila, an important fish disease etiologic agent. Induction time until sedation, anesthesia and recovery time were determined in silver catfish (Rhamdia quelen) through bath exposure (60, 180, 300 or 500 μL L-1). The results showed different biological properties for the isomers being S-(+)-linalool the only active against A. hydrophila at 3.2 mg mL-1. The sedation was induced without differences between the compounds, however R-(-)-linalool promoted faster anesthesia. There were no differences regarding the recovery time of the animals exposed to the linalool isomers. Although both S-(+)- and R-(-)-linalool can be used for sedative purposes, their use in A. hydrophila infection is inadvisable due to the high effective concentration. Considering anesthesia as the main objective, the R-(-)-linalool demonstrated clear advantages at lower concentration.

Linalool, a Piper aduncum essential oil component, has selective activity against Trypanosoma cruzi trypomastigote forms at 4°C

BACKGROUND Recent studies showed that essential oils from different pepper species (Piper spp.) have promising leishmanicidal and trypanocidal activities. OBJECTIVES In search for natural compounds against Trypanosoma cruzi, different forms of the parasite were incubated for 24 h at 28ºC or 4ºC with Piper aduncum essential oil (PaEO) or its main constituents linalool and nerolidol. METHODS PaEO chemical composition was obtained by GC-MS. Drug activity assays were based on cell counting, MTT data or infection index values. The effect of PaEO on the T. cruzi cell cycle and mitochondrial membrane potential was evaluated by flow cytometry. FINDINGS PaEO was effective against cell-derived (IC50/24 h: 2.8 μg/mL) and metacyclic (IC50/24 h: 12.1 μg/mL) trypomastigotes, as well as intracellular amastigotes (IC50/24 h: 9 μg/mL). At 4ºC - the temperature of red blood cells (RBCs) storage in blood banks - cell-derived trypomastigotes were more sensitive to PaEO (IC50/24 h = 3.8 μg/mL) than to gentian violet (IC50/24 h = 24.7 mg/mL). Cytotoxicity assays using Vero cells (37ºC) and RBCs (4ºC) showed that PaEO has increased selectivity for cell-derived trypomastigotes. Flow cytometry analysis showed that PaEO does not affect the cell cycle of T. cruzi epimastigotes, but decreases their mitochondrial membrane potential. GC-MS data identified nerolidol and linalool as major components of PaEO, and linalool had trypanocidal effect (IC50/24 h: 306 ng/mL) at 4ºC. MAIN CONCLUSION The trypanocidal effect of PaEO is likely due to the presence of linalool, which may represent an interesting candidate for use in the treatment of potentially contaminated RBCs bags at low temperature.

Ultrastructural study of morphological changes in Schistosoma mansoni after in vitro exposure to the monoterpene rotundifolone

ABSTRACT INTRODUCTION: Schistosomiasis, a parasitic disease caused by trematode flatworms of the genus Schistosoma, affects more than 200 million people worldwide, and its control is dependent on a single drug, praziquantel. Here, we report the in vitro effect of rotundifolone, a monoterpene isolated from Mentha x villosa (Lamiaceae), on Schistosoma mansoni adult worms. METHODS: The in vitro effect of rotundifolone on adult Schistosoma mansoni was evaluated by analysis of behavior and mortality and through a scanning electron microscopic analysis of ultrastructural changes in the tegument of the worms. RESULTS: At concentrations of 3.54 and 7.09μg/mL-1 rotundifolone, no worm mortality was observed at any of the sampling intervals. A minor reduction in movement of the tail, suckers, and gynecophoral canal membrane was observed after 96 h of exposure to 7.09μg/mL-1 rotundifolone. At 70.96μg/mL-1, a lack of movement was observed from 72h onwards and all worms were deemed dead; similar effects were observed at 48h with 177.4μg/mL-1, and at 24h with 354.8μg/mL-1 and 700.96μg/mL-1. Rotundifolone also caused death of all parasites and separation of coupled pairs into individual males and females after 24h at 354.8μg/mL-1. CONCLUSIONS: The main changes in the tegument induced by the different ROT treatments were: after 24h incubation, bubble lesions spread over the entire body and loss of tubercles occurred in some regions of the ventral region.

Effects of Lippia sidoides essential oil, thymol, p-cymene, myrcene and caryophyllene on rat sciatic nerve excitability

Lippia sidoides Cham is a typical herb species of Northeast Brazil with widespread use in folk medicine. The major constituents of the essential oil of L. sidoides (EOLs) are thymol, p-cymene, myrcene, and caryophyllene. Several studies have shown that the EOLs and its constituents have pharmacological effects, including antibacterial, anti-inflammatory, antioxidant and neuroprotective activity. Therefore, this work aimed to investigate the effects of the EOLs and their main constituents on rat sciatic nerve excitability. The sciatic nerves of adult Wistar rats were dissected and mounted in a moist chamber. Nerves were stimulated by square wave pulses, with an amplitude of 40 V, duration of 100 μs to 0.2 Hz. Both EOLs and thymol inhibited compound action potential (CAP) in a concentration-dependent manner. Half maximal inhibitory concentration for CAP peak-to-peak amplitude blockade were 67.85 and 40 µg/mL for EOLs and thymol, respectively. CAP peak-to-peak amplitude was significantly reduced by concentrations ≥60 µg/mL for EOLs and ≥30 µg/mL for thymol. EOLs and thymol in the concentration of 60 µg/mL significantly increased chronaxie and rheobase. The conduction velocities of 1st and 2nd CAP components were also concentration-dependently reduced by EOLs and thymol in the range of 30-100 µg/mL. Differently from EOLs and thymol, p-cymene, myrcene and caryophyllene did not reduce CAP in the higher concentrations of 10 mM. These data demonstrated that EOLs and thymol inhibited neuronal excitability and were promising agents for the development of new drugs for therapeutic use.

Monoterpenoids (thymol, carvacrol and S-(+)-linalool) with anesthetic activity in silver catfish (Rhamdia quelen): evaluation of acetylcholinesterase and GABAergic activity

This study evaluated the anesthetic potential of thymol and carvacrol, and their influence on acetylcholinesterase (AChE) activity in the muscle and brain of silver catfish (Rhamdia quelen). The AChE activity of S-(+)-linalool was also evaluated. We subsequently assessed the effects of thymol and S-(+)-linalool on the GABAergic system. Fish were exposed to thymol and carvacrol (25, 50, 75, and 100 mg/L) to evaluate time for anesthesia and recovery. Both compounds induced sedation at 25 mg/L and anesthesia with 50-100 mg/L. However, fish exposed to carvacrol presented strong muscle contractions and mortality. AChE activity was increased in the brain of fish at 50 mg/L carvacrol and 100 mg/L thymol, and decreased in the muscle at 100 mg/L carvacrol. S-(+)-linalool did not alter AChE activity. Anesthesia with thymol was reversed by exposure to picrotoxin (GABAA antagonist), similar to the positive control propofol, but was not reversed by flumazenil (antagonist of benzodiazepine binding site), as observed for the positive control diazepam. Picrotoxin did not reverse the effect of S-(+)-linalool. Thymol exposure at 50 mg/L is more suitable than carvacrol for anesthesia in silver catfish, because this concentration did not cause any mortality or interference with AChE activity. Thymol interacted with GABAA receptors, but not with the GABAA/benzodiazepine site. In contrast, S-(+)-linalool did not act in GABAA receptors in silver catfish.

Antibacterial activity of cuticular components from heliotropium species, against staphylococcus aureus and salmonella tiphymurium / Actividad antibacteriana de componentes cuticulares de especies de heliotropium frente a staphylococcus aureus y salmonella tiphymurium

In this communication the antibacterial activity of filifolinol (1), naringenin (2) 3-O-methylgalangin (3) and pinocembrin (4) isolated from the resinous exudates of Heliotropium filifolium and H. sinuatum, were evaluated by flow cytometry against Staphylococcus aureus and Salmonella tiphymurium. The results showed that filifolinol (1) and naringenin (2) were inactive in the range of concentrations used (10 to 1000 ug/mL). On the other hand, pinocembrin (4) produced a decrease in cell surface at 500 ug/mL and the total disappearance of both bacterial populations at 1000 ug/mL. Also, 3-O-methylgalangin (3) showed the total disappearance at 1000 ug/mL of both bacterial populations and a decrease at 200 μg/mL for S. typhimurium and at 500 μg/mL for S. aureus.

En esta comunicación, la actividad antibacteriana de filifolinol (1), naringenina (2), 3-O-methylgalangina (3) y pinocembrina (4) aislados de los exudados resinosos de Heliotropium filifolium y H. sinuatum, fueron evaluados por citometría de flujo frente a Staphylococcus aureus y Salmonella tiphymurium. Los resultados mostraron que filifolinol (1) y naringenina (2) fueron inactivos en el intervalo de concentraciones usadas (10 a 1000 μg / mL). Por otro lado, pinocembrina (4) produce una disminución de la superficie de las células a 500 ug/mL y la desaparición total de ambas poblaciones bacterianas a 1.000 ug/mL. También, 3-O-metilgalangina (3) mostró la desaparición total a 1.000 ug / mL tanto de ambas poblaciones de bacterias y una disminución a 200 ug/mL para S. typhimurium y en 500 μg/mL para S. aureus.

Citronellal-induced disruption of membrane homeostasis in candida albicans and attenuation of its virulence attributes

Abstract: INTRODUCTION There is an increasing burden of multidrug resistance. As a result, deciphering the mechanisms of action of natural compounds with antifungal activity has gained considerable prominence. We aimed to elucidate the probable mechanism of action of citronellal, a monoterpenoid found in the essential oil extracted from Cymbopogon plants, against Candida albicans. METHODS Drug susceptibility was measured by broth microdilution and spot assays. Ergosterol levels were estimated using the alcoholic potassium hydroxide method and H+ extrusion was assessed by monitoring the glucose-induced acidification of the external medium. Virulence traits were studied by hyphal morphogenesis and biofilm formation, along with fungal cell adherence to polystyrene surface and human oral epithelial cells. RESULTS Citronellal showed anticandidal activity against C. albicans and non-albicans species of Candida at a minimum inhibitory concentration of 1 mg/ml. Citronellal interfered with membrane homeostasis, which is the major target of known antifungal drugs, by increasing the hypersensitivity of the fungi to membrane-perturbing agents, reducing ergosterol levels, and diminishing glucose-induced H+ extrusion. In addition, oxidative and genotoxic stresses were induced via an increased production of reactive oxygen species. Furthermore, citronellal inhibited the virulent attributes of yeast-to-hypha transition and biofilm formation. It also reduced cell adherence to polystyrene surface and the human oral epithelial cells. CONCLUSIONS This is the first study to propose the cell membrane, morphogenetic switching, biofilm formation, and cell adherence of Candida albicans as potential targets for the anticandidal activity of citronellal. However, clinical investigations on the therapeutic applications of citronellal are required.

Efecto pediculicida de una formulación en base a Eucaliptus globulus L / Pediculicide effect of a Eucaliptus globulus L formulation

Introduction: Pediculosis capitis is a public health problem with a high prevalence. The emergence of parasite resistance to conventional pediculicide is of great concern worldwide. Objective: To develop alternatives pediculicide, effective and safe, based on the essential oil of Eucaliptus globulus. Method: Through bioassays active concentrations ranges of the essential oil were established, and proceeded to develop a standardized, stable, pharmaceutical form, evaluating its effects on our population. Results: The results showed 100% effectiveness; short time of death, ovicidal action, activity on the adhesion of the egg, and low toxicity. Discussion: In addition to great effect, the inability of the parasite to become resistant to the chemical composition of the essential oil makes this formulation an alternative to the problem of head lice solution.

Introducción: La pediculosis capitis es un problema de salud pública con una alta prevalencia. La aparición de resistencia del parásito a los pediculicidas convencionales es de gran preocupación a nivel mundial. Objetivo: Desarrollar alternativas pediculicidas, efectivas y seguras, en base al aceite esencial de Eucaliptus globulus. Método: A través de bioensayos se establecieron rangos de concentraciones activas del aceite esencial, y se procedió al desarrollo de una forma farmacéutica, estandarizada, estable, evaluando sus efectos en nuestra población. Resultados: Los resultados mostraron 100% de efectividad; corto tiempo de muerte, acción ovicida, actividad sobre la adherencia del huevo, y baja toxicidad. Discusión: Además de la gran efectividad, la imposibilidad del parásito de adquirir resistencia a la composición química del aceite esencial hace de esta formulación una solución alternativa al problema de la pediculosis.

The protective cardiac effects of Β-myrcene after global cerebral ischemia/reperfusion in C57BL/J6 mouse

ABSTRACT PURPOSE: To investigate the protective effect of β-myrcene (MYR) on oxidative and histological damage in mice heart tissue caused global cerebral ischemia/reperfusion (IR) in C57BL/J6 mice. METHODS: Animals(n=40) were randomly divided into four groups: (1)control, (2)IR, (3)MYR and (4)MYR+IR. The control group was received 0.1% carboxymethyl cellulose as a vehicle following a medial incision without carotid occlusion. In the IR group, the bilateral carotid arteries were clipped for 15min, and treated with the vehicle intraperitoneally(ip) for 10 days. MYR (200mg/kg) was received dissolved in 0.1%CMC for 10 days. In the MYR+IR group, the IR model was applied exactly as in the IR group, and then they were treated with MYR 10 days. RESULTS: The cerebral IR caused oxidative damage (increase TBARS, decrease antioxidant parameters). Treatment of MYR was increased in GSH,GPx,CAT,SOD activity while TBARS level was decreased. In addition, degenerative changes in I/R group heart tissue were ameliorated by MYR administration. CONCLUSİON: The administration of β-myrcene protects oxidative and histological damage in the heart tissue after global ischemia-reperfusion and may be useful safe alternative treatment for cardiac tissue after ischemic stroke.

Monoterpene isolated from the essential oil of Trachyspermum ammi is cytotoxic to multidrug-resistant Pseudomonas aeruginosa and Staphylococcus aureus strains

Abstract INTRODUCTION: The aim of this study was to determine whether an herbal extract containing monoterpene exhibited activity against multidrug-resistant Staphylococcus aureus and Pseudomonas aeruginosa isolated from clinical infection samples. METHODS: The essential oil of Trachyspermum ammi (L.) Sprague ex Turrill (Apiaceae) fruit was extracted by hydrodistillation. Fruit residues were treated with hydrochloric acid and re-hydrodistilled to obtain volatile compounds. Compounds in the distilled oil were identified using gas-chromatography (GC) and GC-mass spectrometry (MS). The antibiotic susceptibility of all bacterial isolates was analyzed using both the disc diffusion method and determination of the minimum inhibitory concentration (MIC). The sensitivity of antibiotic-resistant isolates to essential oil was also determined by using the disc diffusion method and MIC determination. RESULTS: Of 26 clinical isolates, 92% were multidrug-resistant (MDR). Aromatic monoterpenes (thymol, paracymene, and gamma-terpinene) were the major (90%) components of the oil. Growth of S. aureus strains was successfully inhibited by the oil, with an inhibitory zone diameter (IZD) between 30-60mm and MIC <0.02μL/mL. The oil had no antimicrobial activity against clinical isolates of P. aeruginosa; rather, it prevented pigment production in these isolates. CONCLUSIONS: This study revealed that the essential oil of Trachyspermum ammi, which contains monoterpene, has good antibacterial potency. Monoterpenes could thus be incorporated into antimicrobial ointment formulas in order to treat highly drug-resistant S. aureus infections. Our findings also underscore the utility of research on natural products in order to combat bacterial multidrug resistance.