RESUMEN

The antifungal and antimycotoxigenic activities of the essential oils (EO) from Cuminum cyminum and Laurus nobilis, and their respective principal compounds, cuminaldehyde and 1,8-cineole, were evaluated against fungi of the genus Aspergillus: A. carbonarius, A. niger, A. ochraceus, and A. westerdijkiae. The antifungal activity was determined by the contact method and the mycelial growth of the fungi was evaluated. Scanning electron microscopic (SEM) images were obtained to suggest modes of action of the compounds analysed. The antimycotoxigenic activity was determined by high-performance liquid chromatograph. Aspergillus carbonarius was completely inhibited by cumin EO (500 µl l-1), by laurel EO and by cuminaldehyde (5000 µl l-1). The cumin EO (500 µl l-1) completely inhibited the growth of A. niger. All the samples inhibited the mycelial growth of A. ochraceus, especially cumin EO and cuminaldehyde (250 µl l-1). Aspergillus westerdijkiae was completely inhibited by cumin EO and cuminaldehyde (1000 µl l-1), by laurel EO and 1,8-cineole (10 000 µl l-1). A decrease in the production of ochratoxin A (OTA) was observed post-treatment, except in A. ochraceus, only inhibited by laurel EO. SEM images showed morphological changes in fungal structures and spore inhibition post-treatment. The results confirmed the antifungal and antimycotoxigenic effect of EO and their principal constituents on fungi evaluated.

Asunto(s)

Antifúngicos , Aspergillus , Cuminum , Laurus , Pruebas de Sensibilidad Microbiana , Aceites Volátiles , Cuminum/química , Aceites Volátiles/farmacología , Aceites Volátiles/química , Aspergillus/efectos de los fármacos , Aspergillus/crecimiento & desarrollo , Aspergillus/metabolismo , Antifúngicos/farmacología , Antifúngicos/química , Laurus/química , Benzaldehídos/farmacología , Eucaliptol/farmacología , Cimenos

RESUMEN

The excessive and indiscriminate use of synthetic insecticides has led to environmental pollution, wildlife destruction, and adverse effects on human health, while simultaneously giving rise to resistance in insect pest populations. This adaptive trait is expressed through various mechanisms, such as changes in the cuticle, heightened activities of detoxifying enzymes, and alterations in the sites of action that reduce their affinity for insecticides. In this context, we associate variation in toxicological response with genomic variation, to identify genetic polymorphisms underlying the different steps of the insect (genotype)-response (phenotype)-insecticide (environment) interaction. Under this framework, our objective was to investigate the genetic factors involved in the toxicological response of D. melanogaster lines when exposed to citronellal and eucalyptol vapors (monoterpenes of plant origin). We quantified KT50 in adult males, representing the time necessary for half of the exposed individuals to be turned upside down (unable to walk or fly). Since the genomes of all lines used are completely sequenced, we perform a Genome Wide Association Study to analyze the genetic underpinnings of the toxicological response. Our investigation enabled the identification of 656 genetic polymorphisms and 316 candidate genes responsible for the overall phenotypic variation. Among these, 162 candidate genes (77.1%) exhibited specificity to citronellal, 45 (21.4%) were specific to eucalyptol, and 3 candidate genes (1.5%) namely CG34345, robo2, and Ac13E, were implicated in the variation for both monoterpenes. These suggest a widespread adaptability in the response to insecticides, encompassing genes influenced by monoterpenes and those orchestrating resistance to the toxicity of these compounds.

Asunto(s)

Monoterpenos Acíclicos , Drosophila melanogaster , Eucaliptol , Insecticidas , Animales , Drosophila melanogaster/efectos de los fármacos , Drosophila melanogaster/genética , Eucaliptol/toxicidad , Insecticidas/toxicidad , Masculino , Monoterpenos Acíclicos/toxicidad , Estudio de Asociación del Genoma Completo , Monoterpenos/toxicidad , Aldehídos/toxicidad , Resistencia a los Insecticidas/genética

RESUMEN

Essential oils (EOs) are natural antioxidant alternatives that reduce skin damage. However, EOs are highly volatile; therefore, their nanoencapsulation represents a feasible alternative to increase their stability and favor their residence time on the skin to guarantee their effect. In this study, EOs of Rosmarinus officinalis and Lavandula dentata were nanoencapsulated and evaluated as skin delivery systems with potential antioxidant activity. The EOs were characterized and incorporated into polymeric nanocapsules (NC-EOs) using nanoprecipitation. The antioxidant activity was evaluated using the ferric thiocyanate method. The ex vivo effects on pig skin were evaluated based on biophysical parameters using bioengineering techniques. An ex vivo dermatokinetic evaluation on pig skin was performed using modified Franz cells and the tape-stripping technique. The results showed that the EOs had good antioxidant activity (>65%), which was maintained after nanoencapsulation and purification. The nanoencapsulation of the EOs favored its deposition in the stratum corneum compared to free EOs; the highest deposition rate was obtained for 1,8-cineole, a major component of L. dentata, at 1 h contact time, compared to R. officinalis with a major deposition of the camphor component. In conclusion, NC-EOs can be used as an alternative antioxidant for skin care.

Asunto(s)

Nanocápsulas , Aceites Volátiles , Animales , Porcinos , Aceites Volátiles/farmacología , Antioxidantes/farmacología , Piel , Eucaliptol , Polímeros

RESUMEN

Schistosomiasis is a tropical disease transmitted in an aqueous environment by cercariae from the Schistosoma genus. This disease affects 200 million people living in risk areas around the world. The control of schistosomiasis is realized by chemotherapy, wastewater sanitation, health education, and mollusk control using molluscicidal agents. This work evaluates the effects of a nanoemulsion containing essential oil from Myrciaria floribunda leaves as a molluscicidal and cercaricidal agent against Biomphalaria glabrata mollusks and Schistosoma mansoni cercariae. The Myrciaria floribunda essential oil from leaves showed nerolidol, ß-selinene, 1,8 cineol, and zonarene as major constituents. The formulation study suggested the F3 formulation as the most promising nanoemulsion with polysorbate 20 and sorbitan monooleate 80 (4:1) with 5% (w/w) essential oil as it showed a smaller droplet size of approximately 100 nm with a PDI lower than 0.3 and prominent bluish reflection. Furthermore, this nanoemulsion showed stability after 200 days under refrigeration. The Myrciaria floribunda nanoemulsion showed LC50 values of 48.11 µg/mL, 29.66 µg/mL, and 47.02 µg/mL in Biomphalaria glabrata embryos, juveniles, and adult mollusks, respectively, after 48 h and 83.88 µg/mL for Schistosoma mansoni cercariae after 2 h. In addition, a survival of 80% was observed in Danio rerio, and the in silico toxicity assay showed lower overall human toxicity potential to the major compounds in the essential oil compared to the reference molluscicide niclosamide. These results suggest that the nanoemulsion of Myrciaria floribunda leaves may be a promising alternative for schistosomiasis control.

Asunto(s)

Moluscocidas , Myrtaceae , Aceites Volátiles , Adulto , Humanos , Aceites Volátiles/farmacología , Moluscocidas/farmacología , Eucaliptol , Niclosamida , Alimentos

RESUMEN

The foraging behavior of the infective juveniles (IJs) of entomopathogenic nematodes (EPNs) relies on host-derived compounds, but in a tri-trophic context, herbivore-induced root volatiles act as signals enhancing the biological control of insect pests by recruiting EPNs. In southern Chile, the EPN Steinernema australe exhibits the potential to control the raspberry weevil, Aegorhinus superciliosus, a key pest of blueberry Vaccinium corymbosum. However, there is no information on the quality of the blueberry root volatile plume or the S. australe response to these chemicals as putative attractants. Here, we describe the root volatile profile of blueberries and the chemotaxis behavior of S. australe towards the volatiles identified from Vaccinium corymbosum roots, infested or uninfested with A. superciliosus larvae. Among others, we found linalool, α-terpineol, limonene, eucalyptol, 2-carene, 1-nonine, 10-undecyn-1-ol, and methyl salicylate in root volatiles and, depending on the level of the emissions, they were selected for bioassays. In the dose-response tests, S. australe was attracted to all five tested concentrations of methyl salicylate, 1-nonine, α-terpineol, and 2-carene, as well as to 100 µg mL-1 of 10-undecyn-1-ol, 0.1 and 100 µg mL-1 of linalool, and 100 µg mL-1 of limonene, whereas eucalyptol elicited no attraction or repellency. These results suggest that some volatiles released from damaged roots attract S. australe and may have implications for the biocontrol of subterranean pests.

Asunto(s)

Arándanos Azules (Planta) , Rabdítidos , Gorgojos , Animales , Limoneno , Quimiotaxis , Eucaliptol , Larva/fisiología , Gorgojos/fisiología , Control Biológico de Vectores/métodos

RESUMEN

Staphylococcus aureus and Staphylococcus chromogenes are pathogens frequently detected in bovine mastitis. Treatment and prevention of this disease have been usually carried on with antimicrobials. However, the emergence of bacterial isolates with antimicrobial resistance has aroused interest in new therapeutic alternatives. Plant essential oils (EOs) have been largely studied as antibacterial treatments. In the present study, EOs from five plants were evaluated for their antibacterial activities against S. aureus and S. chromogenes. Bacterial isolates were obtained in a previous study of clinical cases of bovine mastitis. EOs from lemongrass, eucalyptus, lavender, peppermint, and thyme were obtained by hydrodistillation and their chemical compositions were evaluated by gas chromatography (GC). Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were evaluated for all EOs. The results demonstrated that citral (40.9%), myrcene (24.7%), and geraniol (1.9%) were detected in lemongrass EO; 1,8-cineole (76.9%), α-pinene (8.2%), and ledene (5.1%) in eucalyptus EO; 1,8-cineole (45.2%), camphor (18.2%), and fenchone (14.6%) in lavender EO; L-menthol (38.5%), menthofuran (16.3%), and citronellal (10.6%) in peppermint EO; and thymol (44.2%), p-cymene (24.6%) and 1,8-cineole (9.9%) in thyme EO. More effective antibacterial activities were observed only with the use of lemongrass (MIC and MBC ranging from 0.39 to 3.12 mg/mL and 0.39 to 6.35 mg/mL, respectively) and thyme (MIC and MBC ranging from 0.39 to 1.56 mg/mL and 0.39 to 3.12 mg/mL, respectively). Peppermint, lavender and eucalyptus EOs did not show bactericidal activities. In conclusion, lemongrass and thyme EOs are promising antibacterial alternatives against Staphylococcus species associated with bovine mastitis.

Asunto(s)

Antiinfecciosos , Mastitis Bovina , Aceites Volátiles , Infecciones Estafilocócicas , Animales , Bovinos , Femenino , Aceites Volátiles/farmacología , Aceites Volátiles/química , Staphylococcus aureus , Eucaliptol/farmacología , Staphylococcus , Antiinfecciosos/farmacología , Antibacterianos/farmacología , Antibacterianos/química , Infecciones Estafilocócicas/tratamiento farmacológico , Infecciones Estafilocócicas/veterinaria , Pruebas de Sensibilidad Microbiana

RESUMEN

Hyptis crenata (Pohl) ex Benth is used in traditional medicine as an analgesic to treat general pain. Six Hyptis crenata samples (Hc-1 to Hc-6) were collected in Pará state, Brazil. The leaf essential oils were obtained by hydrodistillation, and GC-MS and GC-FID were used to analyze their chemical compositions. The antioxidant capacity was measured in vitro using DPPH and carotene/linoleic acid assays. Chemometrics analysis (PCA, HCA, and clustered heat map) were used to identify the sample relationships between those collected in this study and those from the literature (Hc-7 to Hc-16) samples. According to the main chemical constituents identified in the samples described in this work and the literature, the sixteen samples were classified into ten groups. Group I was characterized by 1,8-cineole (31.0%), α-pinene (13.6%), (E)-caryophyllene (7.8%), and ß-pinene (7.6%); and Group IV was characterized by 1,8-cineole (17.4-23.5%), α-pinene (15.7-23.5%), ß-pinene (10.5-13.4%), and limonene (8.5-9.7%). Both groups are described for the first time. The total antioxidant capacity was expressed in Trolox Equivalent Antioxidant Capacity values (TEAC): TEAC of Hc-5 (551.9 mg.TE/g) and Hc-6 (475.1 mg.TE/g). In the ß-carotene/linoleic acid assay, the highest inhibition was from Hc-2 (40.0%), Hc-6 (39.0%), and Hc-3 (29.4%).

Asunto(s)

Hyptis , Aceites Volátiles , Aceites Volátiles/farmacología , Aceites Volátiles/química , Antioxidantes/farmacología , Antioxidantes/química , Hyptis/química , Eucaliptol , Brasil , Quimiometría , Ácido Linoleico

RESUMEN

Cyclocephaline beetles are flower visitors attracted primarily by major floral volatiles. Addressing the identity of these volatile compounds is pivotal for understanding the evolution of plant-beetle interactions. We report the identification and field testing of the attractant volatiles from trumpet flowers, Brugmansia suaveolens (Willd.) Sweet (Solanaceae), for the beetle Cyclocephala paraguayensis Arrow (Melolonthidae: Dynastinae). Analysis of headspace floral volatiles revealed 19 compounds, from which eucalyptol (57%), methyl benzoate (16%), and ß-myrcene (6%) were present in the largest amounts, whereas E-nerolidol in much lesser amounts (1.8%). During a first-field assay, traps baited with Mebe alone or blended with the other two major compounds attracted more beetles than myrcene and eucalyptol alone, which did not differ from the negative controls. In a second assay, Mebe and nerolidol attracted more beetles as a blend than individually. Nerolidol was more attractive than Mebe, and all treatments attracted more beetles than negative controls. The number of attracted beetles in the Mebe-nerolidol blend was greater than the combined sum of beetles attracted to these compounds alone, suggesting a synergistic interaction. The attraction of C. paraguayensis by trumpet-flower volatiles supports the beetle's extended preference for sphingophilous plants, especially when cantharophilous (beetle-pollinated) flowers are lacking. This phenomenon, thus, might have contributed to the widespread occurrence of this beetle throughout the Brazilian biomes.

Asunto(s)

Escarabajos , Solanaceae , Animales , Eucaliptol , Flores , Feromonas

RESUMEN

The emergence of itraconazole (ITZ)-resistant Sporothrix brasiliensis in feline and canine cases in southern Brazil has hampered the clinical cure of animal sporotrichosis, encouraging the search for therapeutic alternatives. The promising use of plants extracts from Lamiaceae family is known; however, there are no studies with its major compounds, as γ-terpinene (γTER), 1,8-cineole (1,8CIN), p-coumaric acid (pCOU), and quercetin (QUER). For the first time, we evaluated the antifungal, synergistic, cytotoxic activities and action mechanism of these compounds against S. brasiliensis. For this, 28 S. brasiliensis from cats (n = 24) and dogs (n = 4) and standard strains of S. brasiliensis and S. schenckii (n = 4) were tested by M38-A2 (CLSI), revealing non-wild-type (WT) isolates to ITZ on 54.2% (13/24) and 75% (03/04) of feline and canine isolates, respectively. Of the compounds, γTER stood out against all isolates (MIC/MFC 0.75 to > 3 mg/ml; MIC50 3 mg/ml). However, 1,8CIN, pCOU, and QUER showed little or no activity (MIC50 > 3 mg/ml). Thus, γTER was selected for checkerboard assay, whose combination with ITZ showed synergistic (WT isolates) and indifferent (non-WT isolates) interaction. For action mechanism (sorbitol protection and ergosterol effect), γTER acted in membrane by complexing with fungal ergosterol and at the cell wall level, showing two possible pathways as antifungal target. Finally, cytotoxicity (MTT assay) showed that γTER was the safest compound on MDBK cells, even at a concentration of 3 mg/ml (90.16%). Our findings support that γTER is a potent antifungal candidate for the control of sporotrichosis, including against non-WT S. brasiliensis.

Asunto(s)

Sporothrix , Esporotricosis , Animales , Gatos , Perros , Itraconazol/uso terapéutico , Antifúngicos/uso terapéutico , Esporotricosis/microbiología , Quercetina/uso terapéutico , Eucaliptol/uso terapéutico , Pruebas de Sensibilidad Microbiana

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: The leaf tea of Hyptis crenata has its practical use in the Brazilian Amazon for treating gastrointestinal and liver disorders, sweating induction, and as an anti-inflammatory. AIM OF THE STUDY: Evaluation of the chemical composition, acute oral toxicity, and antinociceptive and anti-inflammatory activities of the H. crenata essential oil. MATERIAL AND METHODS: The essential oil was hydrodistilled and analyzed by GC and GC-MS. The antinociceptive action in mice was evaluated for the peripheral and central analgesic activity (abdominal contortion and hot plate tests), and the xylene-induced ear swelling was carried out for the nociception test. RESULTS: Oxygenated monoterpenes (53.0%) and monoterpene hydrocarbons (38.9%) predominated in the H. crenata oil, being 1,8-cineo1e (35.9%), α-pinene (20.8%), camphor (10.0%), and ß-pinene (7.3%) their primary constituents. The oral oil administration in the mice did not display changes in behavior patterns or animal mortality at 300 and 2000 mg/kg doses. The control group's biochemical parameters (ALP, AST, ALT) displayed a statistical difference from the treated group, unlike the renal parameters, which showed no variation between the groups. Oil reduced the abdominal contortions at doses of 100 (79.5%) and 300 mg/kg (44.4%), while with endodontacin, the dose was 5 mg/kg (75.2%). In addition, the oil could not decrease the paw licking/biting time at doses of 30, 100, and 300 mg/kg. However, it showed a significant antinociceptive effect on the second phase in the formalin test inhibiting licking time, with a reduction of 50.8% (30 mg/kg), 63.4% (100 mg/kg), 58.0% (300 mg/kg), and morphine (4 mg/kg, 78.3%). The oil administration produced significant inhibition of ear edema at all tested doses, with a better effect produced at 30 mg/kg (64.0% inhibition). CONCLUSION: The oil of Hyptis crenata, rich in 1,8-cineole, camphor, α-pinene, and ß-pinene, totaling 74%, displayed low acute toxicity and significant anti-inflammatory activity, with peripheral and no central antinociceptive action. Thus, these results show an actual perspective on using H. crenata oil in developing a phytotherapeutic product.

Asunto(s)

Hyptis , Aceites Volátiles , Analgésicos/farmacología , Analgésicos/uso terapéutico , Animales , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico , Monoterpenos Bicíclicos , Brasil , Alcanfor/uso terapéutico , Edema/inducido químicamente , Edema/tratamiento farmacológico , Eucaliptol/uso terapéutico , Hyptis/química , Ratones , Monoterpenos/farmacología , Monoterpenos/uso terapéutico , Derivados de la Morfina/efectos adversos , Aceites Volátiles/química , Aceites Volátiles/farmacología , Aceites Volátiles/uso terapéutico , Té , Xilenos

RESUMEN

Aedes aegypti L. (Diptera: Culicidae) is an important transmitter of diseases in tropical countries and controlling the larvae of this mosquito helps to reduce cases of diseases such as dengue, zika and chikungunya. Thus, the present study aimed to evaluate the larvicidal potential of the essential oil (EO) of Ocimum basilicum var. minimum (L.) Alef. The EO was extracted by stem distillation and the chemical composition was characterized by gas chromatography coupled with mass spectrometry (GC/MS and GC-FID). The larvicidal activity of EO was evaluated against third instar Ae. aegypti following World Health Organization (WHO) standard protocol and the interaction of the major compounds with the acetylcholinesterase (AChE) was evaluated by molecular docking. The predominant class was oxygenated monoterpenes with a concentration of 81.69% and the major compounds were limonene (9.5%), 1,8-cineole (14.23%), linalool (24.51%) and methyl chavicol (37.41%). The O. basilicum var. minimum EO showed unprecedented activity against third instar Ae. aegypti larvae at a dose-dependent relationship with LC50 of 69.91 (µg/mL) and LC90 of 200.62 (µg/mL), and the major compounds were able to interact with AChE in the Molecular Docking assay, indicating an ecological alternative for mosquito larvae control.

Asunto(s)

Aedes , Insecticidas , Ocimum basilicum , Aceites Volátiles , Infección por el Virus Zika , Virus Zika , Acetilcolinesterasa , Animales , Eucaliptol , Cromatografía de Gases y Espectrometría de Masas , Insecticidas/química , Insecticidas/farmacología , Larva , Limoneno , Simulación del Acoplamiento Molecular , Monoterpenos , Aceites Volátiles/química , Aceites Volátiles/farmacología , Fitoquímicos/farmacología

RESUMEN

1,8-Cineole, limonene and α-terpineol are the major terpenes present in Callistemon citrinus. This study reports for the first time that terpenes attenuate the oxidative stress in rats fed with high-fat-sucrose diet (HFSD) via antioxidant and anti-inflammatory mechanisms. Thirty-six male Wistar rats were divided into six groups (n = 6). Control (fed standard food, HFSD (fed with 41.7% fat and 16.6% sucrose), HFSD + 1,8-cineole (0.88 mg/kg body weight), limonene (0.43 mg/kg body weight), α-terpineol (0.32 mg/kg body weight) and a mixture of the three terpenes, given daily by gavage for 15 weeks. Morphometric and biochemical parameters were taken. Paraoxonase (PON1), reduced glutathione (GSH), lipid peroxidation products malondialdehyde (MDA) and hydroxyalkenals (HNE), advanced oxidation protein products (AOPP) and pro-inflammatory cytokines were measured in liver homogenates. All terpenes showed a remarkable reduction in weight gain, fat deposition, serum glucose and, triacylglycerol levels. However, terpenes presented different effects on the hepatic cell and the oxidative biomarkers. Conversely, the three terpenes and the mixture showed the same positive effect on the tumor necrosis factor alpha (TNFα), interleukin-6 (IL-6), leptin and adiponectin levels. Finally, 1,8-cineole, limonene and α-terpineol demonstrate significant anti-inflammatory effects and differential effects on the oxidative stress, suggesting the importance of these terpenes in Callistemon citrinus activities.

Asunto(s)

Myrtaceae , Terpenos , Animales , Antioxidantes/metabolismo , Antioxidantes/farmacología , Peso Corporal , Dieta Alta en Grasa/efectos adversos , Eucaliptol/metabolismo , Eucaliptol/farmacología , Limoneno/metabolismo , Limoneno/farmacología , Hígado/metabolismo , Masculino , Estrés Oxidativo , Ratas , Ratas Wistar , Sacarosa/metabolismo , Terpenos/farmacología

RESUMEN

The aim of present study was to evaluate chemical composition and different biological activities viz., pharmacological and antioxidant activities of essential oils. The chemical composition of essential oils was determined by gas chromatography/mass spectrometry while biological activities were evaluated by standard protocols. Essential oils of Hedychium spicatum Sm. from two different ecological niches viz; Nainital (Site-I) and Himachal Pradesh (Site-II) of India revealed the qualitative and quantitative chemo-diversity. Both the oils were dominated by oxygenated terpenoids. Major marker compounds identified were eucalyptol, camphor, linalool, α-eudesmol, 10-epi-γ-eudesmol, and iso-borneol. Both the oils exhibited anti-inflammatory activity suppressing 17.60 % to 33.57 % inflammation at 100mg/kg b. wt. dose levels compared to ibuprofen-treated group (40.06 %). The sub-acute inflammation in oils-treated mice groups (50 and 100 mg/kg b. wt.) increased on day 2 but showed a gradual decrease from day 3 onwards and then recovered to normal by day 10. The antinociception percentage for doses (50 and 100 mg/kg b. wt.) ranged from 33.70-40.46 % in Site-I and 30.34-42.39 % in Site-II compared to standard drug, ibuprofen (43.08 %). The oils also showed a good antipyretic effect by suppressing Brewer's yeast (Saccharomyces cerevisiae) induced pyrexia after oil dose injection. The oils also exhibited good antioxidant activity.

Asunto(s)

Ibuprofeno/química , Aceites Volátiles , Zingiberaceae , Animales , Antifúngicos/farmacología , Antioxidantes/análisis , Alcanfor/análisis , Alcanfor/farmacología , Eucaliptol/análisis , Ibuprofeno/análisis , Ibuprofeno/farmacología , Inflamación , Ratones , Aceites Volátiles/química , Aceites de Plantas/química , Rizoma/química , Zingiberaceae/química

RESUMEN

Coffee (Coffea L.) is one of the main crops produced globally. Its contamination by the fungus Hemileia vastatrix Berkeley and Broome has been economically detrimental for producers. The objective of this work was to extract and characterize the essential oils from Eucalyptus citriodora Hook, Eucalyptus camaldulensis Dehn and Eucalyptus grandis Hill ex Maiden, produce and characterize nanoparticles containing these essential oils and evaluate the in vivo and in vitro antifungal activity of free and nanoencapsulated essential oils. The principal constituent of the essential oil from E. citriodora was citronellal; that from E. grandis was α-pinene; and that from E. camaldulensis was 1,8-cineol. The in vitro antifungal activity against the fungus H. vastatrix was 100% at a concentration of 1000 µl l-1 for all the oils and nanoparticles containing these natural products. The sizes of the nanoparticles produced with the essential oils from E. citriodora, E. camaldulensis and E. grandis were 402·13 nm, 275·33 nm and 328·5 nm, respectively, with surface charges of -11·8 mV, -9·24 mV and - 6·76 mV, respectively. Fourier transform infrared analyses proved that the encapsulation of essential oils occurred in the polymeric matrix of poly(ε-caprolactone). The incorporation of essential oils into biodegradable poly(ε-caprolactone) nanoparticles increased their efficiency as biofungicides in the fight against coffee rust, decreasing the severity of the disease by up to 90·75% after treatment with the nanoparticles containing the essential oil from E. grandis.

Asunto(s)

Eucalyptus , Nanopartículas , Aceites Volátiles , Antifúngicos/farmacología , Basidiomycota , Eucaliptol , Aceites Volátiles/farmacología , Aceites de Plantas , Poliésteres

RESUMEN

One of the main vectors for malaria in Latin America is Anopheles pseudopunctipennis (Theobald), whereas Aedes aegypti (L.) is the primary vector of dengue, yellow fever, Zika and chikungunya viruses. The use of repellents is recommended as a personal protection method against these mosquitoes. However there are very few studies evaluating the effect of repellents on An. pseudopunctipennis. The use of a Petri dish to study repellence has been applied by several authors on flies, cockroaches, kissing bugs and mosquitoes, being a valuable technique for species that are difficult to breed under laboratory conditions, such as An. pseudopunctipennis. In the present study, we evaluated the repellence of the essential oil of the Eucalyptus nitens (Shining gum), its main component (1,8-cineole) and the commercial repellent DEET on An. pseudopunctipennis and Ae. aegypti adult females using the plaque repellency method coupled to EthoVision XT10.1 video-tracking software. Repellent effect and locomotor activity were studied through a repellence index (RI) together with an axis constructed from the behavioural variables obtained using the tracking software. DEET repellent effect was observed at 0.01 mg/mL for Ae. aegypti and 0.01 and 0.1 mg/mL for An. pseudopunctipennis. In addition, the essential oil showed significant repellence at 1 and 10 mg/mL for Ae. aegypti, and 1, 5, 10 and 25 mg/mL for An. pseudopunctipennis. Neither of these species were repelled at any concentration of 1,8-cineole. This is the first study that evaluates these compounds on An. pseudopunctipennis females and quantifies their effects on the activity of both species.

Asunto(s)

Aedes , Anopheles , Repelentes de Insectos , Aceites Volátiles , Infección por el Virus Zika , Virus Zika , Animales , DEET , Eucaliptol , Femenino , Repelentes de Insectos/farmacología , Mosquitos Vectores , Aceites Volátiles/farmacología , Fitomejoramiento

RESUMEN

1,8-Cineole is a naturally occurring compound found in essential oils of different plants and has well-known anti-inflammatory and antimicrobial activities. In the present work, we aimed to investigate its potential antimalarial effect, using the following experimental models: (1) the erythrocytic cycle of Plasmodium falciparum; (2) an adhesion assay using brain microvascular endothelial cells; and (3) an experimental cerebral malaria animal model induced by Plasmodium berghei ANKA infection in susceptible mice. Using the erythrocytic cycle of Plasmodium falciparum, we characterized the schizonticidal effect of 1,8-cineole. This compound decreased parasitemia in a dose-dependent manner with a half maximal inhibitory concentration of 1045.53 ± 63.30 µM. The inhibitory effect of 972 µM 1,8-cineole was irreversible and independent of parasitemia. Moreover, 1,8-cineole reduced the progression of intracellular development of the parasite over 2 cycles, inducing important morphological changes. Ultrastructure analysis revealed a massive loss of integrity of endomembranes and hemozoin crystals in infected erythrocytes treated with 1,8-cineole. The monoterpene reduced the adhesion index of infected erythrocytes to brain microvascular endothelial cells by 60%. Using the experimental cerebral malaria model, treatment of infected mice for 6 consecutive days with 100 mg/kg/day 1,8-cineole reduced cerebral edema with a 50% reduction in parasitemia. Our data suggest a potential antimalarial effect of 1,8-cineole with an impact on the parasite erythrocytic cycle and severe disease.

Asunto(s)

Antimaláricos , Edema Encefálico , Malaria Cerebral , Animales , Antimaláricos/química , Antimaláricos/farmacología , Antimaláricos/uso terapéutico , Modelos Animales de Enfermedad , Células Endoteliales , Eucaliptol/farmacología , Malaria Cerebral/tratamiento farmacológico , Malaria Cerebral/parasitología , Malaria Cerebral/prevención & control , Ratones , Ratones Endogámicos C57BL , Monoterpenos/farmacología , Monoterpenos/uso terapéutico , Parasitemia/tratamiento farmacológico , Parasitemia/parasitología , Plasmodium berghei , Plasmodium falciparum

RESUMEN

Essential oils (EOs) produced by plants in the Lamiaceae family may provide new insecticidal molecules. Novel control compounds are needed to control Drosophila suzukii (Matsumura), a severe economic invasive pest of thin-skinned fruit crops. Thus, we characterized the main compounds of EOs from three rosemary Rosmarinus officinalis ecotypes (ECOs) and evaluated their toxicity to D. suzukii adults, deterrence of oviposition behavior, and histological alterations in larvae. Additionally, we analyzed the lethal and sublethal effect on the pupal parasitoid Trichopria anastrephae. The main compounds identified in the R. officinalis ECOs were α-pinene, camphor and 1,8-cineole. In bioassays via topical application or ingestion, ECOs and their major compounds showed high toxicity on D. suzukii adults and a lower concentration could kill 50% and 90% of flies compared to spinetoram. The dry residues of a-pinene, 1,8-cineole, and camphor provided a repellent effect by reducing D. suzukii oviposition by ~47% compared to untreated fruit. Histological sections of 3rd instar larval D. suzukii posttreatment revealed damage to the fat body, Malpighian tubules, brain, salivary gland, and midgut, which contributed to high larval and pupal mortality. Survival and parasitism by adult T. anastrephae were not affected. Thus, R. officinalis EO and their compounds have potential for developing novel insecticides to manage D. suzukii.

Asunto(s)

Insecticidas , Aceites Volátiles , Rosmarinus , Animales , Alcanfor , Drosophila , Ecotipo , Eucaliptol , Femenino , Insecticidas/farmacología , Larva , Aceites Volátiles/farmacología , Pupa

RESUMEN

Abstract Rheumatoid arthritis (RA) is an inflammatory disease that utilizes nonbiologic and biologic drugs for appropriate disease management. However, high cost, adverse effects, reduced effectiveness, and risk of infection have stimulated the search for safer and more efficacious therapeutic strategies. In the present study, we aimed to evaluate the anti-inflammatory and analgesic properties of eucalyptol in an experimental model of arthritis. Mice were administered zymosan or saline intra-articularly. One hour before the zymosan administration, the mice were treated with oral eucalyptol (200-400 mg/kg) and vehicle. Cell influx, neutrophils, lymphocytes, and monocytes were measured in joint exudates. Joint pain was assessed using paw-pressure tests. Orally administered eucalyptol (200 and 400 mg/kg) significantly reduced cell influx, as well as neutrophils, lymphocytes, and monocytes, when compared with the control. Eucalyptol at a dose of 400 mg/kg significantly reversed joint pain and demonstrated analgesic activity (60%); however, 200 mg/kg failed to alter joint pain. These results indicate that oral eucalyptol promotes anti-inflammatory and analgesic activity in mice subjected to zymosan-induced arthritis.

Asunto(s)

Animales , Masculino , Ratones , Artritis/inducido químicamente , Zimosan/farmacología , Movimiento Celular/efectos de los fármacos , Administración Oral , Eucaliptol/análisis , Analgésicos/administración & dosificación , Antiinflamatorios/administración & dosificación

RESUMEN

1,8-cineole is a monoterpene commonly used by the food, cosmetic, and pharmaceutical industries owing to its flavor and fragrances properties. In addition, this bioactive monoterpene has demonstrated bactericidal and fungicidal activities. However, such activities are limited due to its low aqueous solubility and stability. This study aimed to develop nanoemulsion containing cineole and assess its stability and antibacterial activity in this context. The spontaneous emulsification method was used to prepare nanoemulsion (NE) formulations (F1, F2, F3, F4, and F5). Following the development of NE formulations, we chose the F1 formulation that presented an average droplet size (in diameter) of about 100 nm with narrow size distribution (PdI <0.2) and negative zeta potential (∼ - 35 mV). According to the analytical centrifugation method with photometric detection, F1 and F5 formulations were considered the most stable NE with lower droplet migration velocities. In addition, F1 formulation showed high incorporation efficiency (> 80 %) and TEM analyses demonstrated nanosized oil droplets with irregular spherical shapes and without any aggregation tendency. Antibacterial activity assessment showed that F1 NE was able to enhance the cineole action against Staphylococcus aureus, Enterococcus faecalis, and Streptococcus pyogenes. Therefore, using a simple and reproducible method of low energy emulsification we designed a stable nanoemulsion containing 1,8-cineole with improved antibacterial activity against Gram-positive strains.

Asunto(s)

Antibacterianos/química , Emulsiones/química , Eucaliptol/química , Nanoestructuras/química , Antibacterianos/farmacología , Estabilidad de Medicamentos , Enterococcus faecalis/efectos de los fármacos , Eucaliptol/farmacología , Pruebas de Sensibilidad Microbiana , Tamaño de la Partícula , Staphylococcus aureus/efectos de los fármacos

RESUMEN

This work aimed to study the chemical composition, cholinesterase inhibitory activity, and enantiomeric analysis of the essential oil from the aerial parts (leaves and flowers) of the plant Lepechinia paniculata (Kunth) Epling from Ecuador. The essential oil (EO) was obtained through steam distillation. The chemical composition of the oil was evaluated by gas chromatography, coupled to mass spectrometry (GC-MS) and a flame ionization detector (GC-FID). The analyses led to the identification of 69 compounds in total, of which 40 were found in the leaves and 29 were found in the flowers of the plant. The major components found in the oil were 1,8-Cineole, ß-Pinene, δ-3-Carene, α-Pinene, (E)-Caryophyllene, Guaiol, and ß-Phellandrene. Flower essential oil showed interesting selective inhibitory activity against both enzymes AChE (28.2 ± 1.8 2 µg/mL) and BuChE (28.8 ± 1.5 µg/mL). By contrast, the EO of the leaves showed moderate mean inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), with IC50 values of 38.2 ± 2.9 µg/mL and 47.4 ± 2.3 µg/mL, respectively.

Asunto(s)

Acetilcolinesterasa/química , Butirilcolinesterasa/química , Inhibidores de la Colinesterasa/farmacología , Lamiaceae/efectos de los fármacos , Aceites Volátiles/química , Extractos Vegetales/química , Hojas de la Planta/química , Monoterpenos Ciclohexánicos/química , Eucaliptol/química , Flores/química , Cromatografía de Gases y Espectrometría de Masas , Hidrocarburos , Concentración 50 Inhibidora , Sesquiterpenos Policíclicos/química , Sesquiterpenos de Guayano/química , Estereoisomerismo