Lippia gracilis essential oil in ß-cyclodextrin inclusion complexes: an environmentally safe formulation to control Aedes aegypti larvae.

BACKGROUND: One of the most efficient ways to prevent arboviruses, such as dengue fever, yellow fever, chikungunya and Zika, is by controlling their vector, the Aedes aegypti. Because this vector is becoming resistant to most larvicides used, the development of new larvicides should be considered. ß-Cyclodextrin (ß-CD) complexes have been investigated as an interesting way of enabling the use of essential oils in water as larvicides. This study comprised the development of Lippia gracilis essential oil (LGEO) and ß-CD inclusion complexes for control of Ae. aegypti. RESULTS: Thermal analysis clearly showed the formation of complexes using kneading and co-evaporation methods. Gas chromatography analysis showed that kneading without co-solvent (KW) gave the highest content (∼ 15%) of the LGEO major component. Moreover, KW showed that the complex had a 50% lethal concentration (LC50 ; 33 ppm) lower than that of pure LGEO (39 ppm); in other words, complexing LGEO with ß-CD improved the larvicidal activity. In addition, LGEO complexed with ß-CD (KW) was not harmful to non-target organisms at the concentrations needed to control Ae. aegypti larvae. CONCLUSION: The inclusion complex with LGEO was a feasible formulation, being economically viable, easy-to-apply and without impact on non-target organisms and, therefore, is a potential alternative larvicide for Ae. aegypti control. © 2018 Society of Chemical Industry.

Essential Oil of Aristolochia trilobata: Synthesis, Routes of Exposure, Acute Toxicity, Binary Mixtures and Behavioral Effects on Leaf-Cutting Ants.

Plants of the genus Aristolochia have been frequently reported as important medicinal plants. Despite their high bioactive potential, to date, there are no reports of their effects on leaf-cutting ants. Therefore, the present study aimed to evaluate the insecticidal activity of the essential oil of Aristolochia trilobata and its major components on Atta sexdens and Acromyrmex balzani, two species of leaf-cutting ants. The bioassays were performed regarding routes of exposure, acute toxicity, binary mixtures of the major components and behavioral effects. Twenty-five components were identified in the essential oil of A. trilobata using a gas chromatographic system equipped with a mass spectrometer and a flame ionization detector. The components found in higher proportions were sulcatyl acetate, limonene, p-cymene and linalool. The essential oil of A. trilobata and its individual major components were efficient against A. balzani and A. sexdens workers when applied by fumigation. These components showed fast and efficient insecticidal activity on ants. The components acted synergistically and additively on A. balzani and A. sexdens, respectively, and caused a strong repellency/irritability in the ants. Thus, our results demonstrate the great potential of the essential oil of A. trilobata and its major components for the development of new insecticides.

Anti-cryptococcal activity of ethanol crude extract and hexane fraction from Ocimum basilicum var. Maria bonita: mechanisms of action and synergism with amphotericin B and Ocimum basilicum essential oil.

CONTEXT: Ocimum basilicum L. (Lamiaceae) has been used in folk medicine to treat headaches, kidney disorders, and intestinal worms. OBJECTIVE: This study evaluates the anti-cryptococcal activity of ethanol crude extract and hexane fraction obtained from O. basilicum var. Maria Bonita leaves. MATERIALS AND METHODS: The MIC values for Cryptococcus sp. were obtained according to Clinical and Laboratory Standards Institute in a range of 0.3-2500 µg/mL. The checkerboard assay evaluated the association of the substances tested (in a range of 0.099-2500 µg/mL) with amphotericin B and O. basilicum essential oil for 48 h. The ethanol extract, hexane fraction and associations in a range of 0.3-2500 µg/mL were tested for pigmentation inhibition after 7 days of treatment. The inhibition of ergosterol synthesis and reduction of capsule size were evaluated after the treatment with ethanol extract (312 µg/mL), hexane fraction (78 µg/mL) and the combinations of essential oil + ethanol extract (78 µg/mL + 19.5 µg/mL, respectively) and essential oil + hexane fraction (39.36 µg/mL + 10 µg/mL, respectively) for 24 and 48 h, respectively. RESULTS: The hexane fraction presented better results than the ethanol extract, with a low MIC (156 µg/mL against C. neoformans T444 and 312 µg/mL against C. neoformans H99 serotype A and C. gattii WM779 serotype C). The combination of the ethanol extract and hexane fraction with amphotericin B and essential oil enhanced their antifungal activity, reducing the concentration of each substance needed to kill 100% of the inoculum. The substances tested were able to reduce the pigmentation, capsule size and ergosterol synthesis, which suggest they have important mechanisms of action. CONCLUSIONS: These results provide further support for the use of ethanol extracts of O. basilicum as a potential source of antifungal agents.

Acaricidal efficacies of Lippia gracilis essential oil and its phytochemicals against organophosphate-resistant and susceptible strains of Rhipicephalus (Boophilus) microplus.

Plant-derived natural products can serve as an alternative to synthetic compounds for control of ticks of veterinary and medical importance. Lippia gracilis is an aromatic plant that produces essential oil with high content of carvacrol and thymol monoterpenes. These monoterpenes have high acaricidal activity against Rhipicephalus (Boophilus) microplus. However, there are no studies that show efficacy differences of essential oils between susceptible and organophosphate resistant strains of R. (B.) microplus. The aim of the present study was to compare acaricidal effects of essential oils extracted from two different genotypes of L. gracilis and the main monoterpenes on larvae of both susceptible and organophosphate resistant R. (B.) microplus larvae. The efficacy of the essential oil of two genotypes of L. gracilis (106 and 201) and their monoterpenes carvacrol and thymol was measured using the larval immersion test on coumaphos-resistant and susceptible strains of R. (B.) microplus. Lethal concentrations were calculated using GraphPad Prism 6.0. Chemical analysis was performed by GC-MS and FID. Thymol and carvacrol were observed to be major constituents in 106 and 201L. gracilis genotype essential oils, respectively. Essential oils of both genotypes were more effective against organophosphate-resistant tick strain than susceptible tick strain. Carvacrol was 3.2 times more toxic to organophosphate resistant strain than to susceptible strain. Thymol was equally toxic to resistant and susceptible tick strains. The significantly higher efficacy monoterpene carvacrol against resistant ticks may lead to development of new natural product acaricide formulations for use to control organophosphate resistant R. (B.) microplus populations.

Volatile profile of basil cultivars and hybrids / Volatile perfil de cultivares de albahaca y los híbridos

The aim of this study was to evaluate the volatile profile as a result of hybridization. Data were analyzed by ANOVA, Tukey test and Principal Component Analysis. Hybridization provided the appearance of compounds in hybrids, and these compounds are absent in the parental volatile profile. The new compounds were: camphor, neral, geranial, beta-selinene, bicyclogermacrene, (E)-caryophyllene and methyl chavicol, for the hybrid 'Genovese' x 'Maria Bonita'; and camphor, for the hybrid 'Sweet Dani' x 'Genovese'.

El objetivo de este estudio fue evaluar el perfil de volátiles como resultado de la hibridación. Los datos fueron analizados por ANOVA, prueba de Tukey y Análisis de Componentes Principales. La hibridación proporcionó la aparición de nuevos compuestos híbridos que no están presentes en el perfil de volátiles de los parentales, como por ejemplo el alcanfor, el neral, el geranial A, el beta-selineno, el biciclogermacrene, el (E)-cariofileno y el metil chavicol para el híbrido 'Genovese' x 'Maria Bonita', y el alcanfor para el híbrido 'Sweet Dani' x 'Genovese'.

Synergism Effect of the Essential Oil from Ocimum basilicum var. Maria Bonita and Its Major Components with Fluconazole and Its Influence on Ergosterol Biosynthesis.

The aim of this study was to evaluate the activity of the EO and its major components of Ocimum basilicum var. Maria Bonita, a genetically improved cultivar, against the fluconazole sensitive and resistant strains of Candida albicans and Cryptococcus neoformans. Geraniol presented better results than the EO, with a low MIC (76 µg/mL against C. neoformans and 152 µg/mL against both Candida strains). The combination of EO, linalool, or geraniol with fluconazole enhanced their antifungal activity, especially against the resistant strain (MIC reduced to 156, 197, and 38 µg/mL, resp.). The ergosterol assay showed that subinhibitory concentrations of the substances were able to reduce the amount of sterol extracted. The substances tested were able to reduce the capsule size which suggests they have an important mechanism of action. Transmission electron microscopy demonstrated cell wall destruction of C. neoformans after treatment with subinhibitory concentrations. In C. albicans ultrastructure alterations such as irregularities in the membrane, presence of vesicles, and cell wall thickening were observed. The biofilm formation was inhibited in both C. albicans strains at MIC and twice MIC. These results provide further support for the use of O. basilicum EO and its major components as a potential source of antifungal agents.

Preparation, Characterization, and Pharmacological Activity of Cymbopogon winterianus Jowitt ex Bor (Poaceae) Leaf Essential Oil of ß-Cyclodextrin Inclusion Complexes.

This study aimed to evaluate the orofacial antinociceptive effect of the Cymbopogon winterianus essential oil (LEO) complexed in ß-cyclodextrin (LEO-CD) and to assess the possible involvement of the central nervous system (CNS). The LEO was extracted, chromatographed, and complexed in ß-cyclodextrin. The complex was characterized by differential scanning calorimetry (DSC) and thermogravimetry derivative (TG/DTG). Male Swiss mice (2-3 months) were treated with LEO-CD (50-200 mg/kg, p.o.), vehicle (distilled water, p.o.), or standard drug (i.p.) and subjected to the orofacial nociception formalin-, capsaicin-, and glutamate-induced. After the formalin test, the animals were perfused and the brains subjected to immunofluorescence for Fos. The rota-rod test (7 rpm/min) was carried out. Geraniol (37.57%) was the main compound of LEO. DSC and TG/DTG proved the complexation. The orofacial nociceptive behavior was significantly (p < 0.05) reduced. The number of Fos-positive cells was significantly changed in the dorsal raphe nucleus (p < 0.01), locus coeruleus (p < 0.001), trigeminal nucleus (p < 0.05), and trigeminal thalamic tract (p < 0.05). LEO-CD did not cause changes in motor coordination in the rota-rod test. Thus, our results suggested that LEO-CD has an orofacial antinociceptive profile, probably mediated by the activation of the CNS without changing the motor coordination.

Produção de óleo essencial de Ocimum basilicum L. em diferentes épocas, sistemas de cultivo e adubações / Production of Ocimum basilicum L. essential oil in differents seasons, systems of plantyng and types of fertilizers

Climatic factors influences the production of active principles of aromatic plants. We evaluated the biomass and essential oil of basil (Ocimum basilicum L.). Basil growns mainly by small farmers seeking to sell their leaves, which can be used fresh, dried, as flavorings or seasonings. The experimental design was completely randomized in a 2x2x2 factorial (growing seasons, environments and different kinds of fertilizers). We analyzed plant height, length and width of leaves, fresh and dry weight, yield and essential oil. Comparing the season and environments, the results showed that the plant height were higher in second season. The fertilization did not significantly influence the development and production of essential oils of basil at the two cropping seasons. The cultivation in winter in a protected environment favored crop development, production and essential oil yield.

Os fatores climáticos influenciam na produção de princípios ativos das plantas aromáticas. Neste trabalho, avaliou-se a biomassa e o óleo essencial de Ocimum basilicum L. Essa é uma planta cultivada principalmente por pequenos agricultores que tentam vender suas folhas, que podem ser usadas frescas, secas, como aromatizantes ou em temperos. O delineamento experimental foi inteiramente casualizado, em esquema fatorial 2 x 2 x 2 (épocas de cultivo, ambientes e tipos de adubações). Foram analisadas as seguintes variáveis: altura da planta, comprimento e largura de folhas, peso e rendimento de óleo essencial. Comparando-se épocas e ambientes de cultivo, os resultados mostraram que altura das plantas foi maior na segunda época. O tipo de adubação não influenciou significativamente no desenvolvimento e na produção de óleos essenciais de manjericão nas duas épocas de cultivo. Além disso, o cultivo no inverno em ambiente protegido favoreceu o desenvolvimento, a produção e o rendimento de óleo essencial.

Cyclodextrin-complexed Ocimum basilicum leaves essential oil increases Fos protein expression in the central nervous system and produce an antihyperalgesic effect in animal models for fibromyalgia.

O. basilicum leaves produce essential oils (LEO) rich in monoterpenes. The short half-life and water insolubility are limitations for LEO medical uses. ß-Cyclodextrin (ß-CD) has been employed to improve the pharmacological properties of LEO. We assessed the antihyperalgesic profile of LEO, isolated or complexed in ß-CD (LEO/ß-CD), on an animal model for fibromyalgia. Behavioral tests: mice were treated every day with either LEO/ß-CD (25, 50 or 100 mg/kg, p.o.), LEO (25 mg/kg, p.o.), tramadol (TRM 4 mg/kg, i.p.) or vehicle (saline), and 60 min after treatment behavioral parameters were assessed. Therefore, mice were evaluated for mechanical hyperalgesia (von Frey), motor coordination (Rota-rod) and muscle strength (Grip Strength Metter) in a mice fibromyalgia model. After 27 days, we evaluated the central nervous system (CNS) pathways involved in the effect induced by experimental drugs through immunofluorescence protocol to Fos protein. The differential scanning analysis (DSC), thermogravimetry/derivate thermogravimetry (TG/DTG) and infrared absorption spectroscopy (FTIR) curves indicated that the products prepared were able to incorporate the LEO efficiently. Oral treatment with LEO or LEO-ßCD, at all doses tested, produced a significant reduction of mechanical hyperalgesia and we were able to significantly increase Fos protein expression. Together, our results provide evidence that LEO, isolated or complexed with ß-CD, produces analgesic effects on chronic non-inflammatory pain as fibromyalgia.

Insecticidal and repellence activity of the essential oil of Pogostemon cablin against urban ants species.

Ants are highly abundant in neotropical regions, with certain species adapted to the urban environment, where they can cause damage to human health. The main method for controlling ants consists of using organosynthetic insecticides, which are potentially toxic to the environment. Essential plant oils are considered a viable alternative to the use of conventional insecticides. In this study, we analyze the bioinsecticidal activity and repellence of patchouli essential oil (Pogostemon cablin) against three species of urban ants: Camponotus melanoticus, Camponotus novograndensis, and Dorymyrmex thoracicus. The chemical composition of the essential oil was analyzed by GC-MS and GC-FID. The major compounds were patchoulol (36.6%) followed by α-bulnesene (13.95%), and α-guaiene (11.96%). Toxicity and repellency bioassays were performed using the essential oil over the ants, and mortality evaluations were performed at 4, 24, and 48 h after performing the bioassays. Mortality percentage of the ants on 7 µg/mg was on average 84%. The essential oil of P. cablin displayed toxicity against all three species of urban ants, with the lowest LD50 being observed for D. thoracicus (2.02 µg oil/mg insect) after 48 h of exposure compared to C. melanoticus (2.34 µg oil/mg insect) and C. novogranadensis (2.95 µg oil/mg insect). The essential oil of P. cablin was strongly repellent to the three species of ants in all concentrations tested (0.01% and 1% v/v). Considering the potential toxicity and repellency of the P. cablin essential oil to the urban ants, future studies could investigate the practical application of this oil to control of this insects.

Evaluation of the cytotoxic activity of some Brazilian medicinal plants.

Plants are promising sources of new bioactive compounds. The aim of this study was to investigate the cytotoxic potential of nine plants found in Brazil. The species studied were: Annona pickelii Diels (Annonaceae), Annona salzmannii A. DC. (Annonaceae), Guatteria blepharophylla Mart. (Annonaceae), Guatteria hispida (R. E. Fr.) Erkens & Maas (Annonaceae), Hancornia speciosa Gomes (Apocynaceae), Jatropha curcas L. (Euphorbiaceae), Kielmeyera rugosa Choisy (Clusiaceae), Lippia gracilis Schauer (Verbenaceae), and Hyptis calida Mart. Ex Benth (Lamiaceae). Different types of extractions from several parts of plants resulted in 43 extracts. Their cytotoxicity was tested against HCT-8 (colon carcinoma), MDA-MB-435 (melanoma), SF-295 (glioblastoma), and HL-60 (promielocitic leukemia) human tumor cell lines, using the thiazolyl blue test (MTT) assay. The active extracts were those obtained from G. blepharophylla, G. hispida, J. curcas, K. rugosa, and L. gracilis. In addition, seven compounds isolated from the active extracts were tested; among them, ß-pinene found in G. hispida and one coumarin isolated from K. rugora showed weak cytotoxic activity. In summary, this manuscript contributes to the understanding of the potentialities of Brazilian plants as sources of new anticancer drugs.

Phytochemical screening, antinociceptive and anti-inflammatory activities of Chrysopogon zizanioides essential oil

Chrysopogon zizanioides (L.) Roberty, Poaceae, is a plant widely used in northeast Brazil in folk medicine for the treatment of various pathological conditions, including inflammatory pain. The present study evaluated the antinociceptive and anti-inflammatory effects of C. zizanioides essential oil (EO) in rodents. EO was further characterized by GC/MS. The major components of EO were identified as khusimol (19.57%), E-isovalencenol (13.24%), α-vetivone (5.25%), β-vetivone (4.87%) and hydroxy-valencene (4.64%). Following intraperitoneal injection (i.p.), EO at 50 and 100 mg/kg significantly reduced the number of writhes (51.9 and 64.9%, respectively) and the number of paw licks during phase 2 (56.7 and 86.2%, respectively) of a formalin model when compared to control group animals. However, EO-treated mice were ineffective at all doses in hot-plate and rota-rod tests. The EO inhibited the carrageenan-induced leukocyte migration to the peritoneal cavity in a dose-dependent manner (34.7, 35.4, and 62.5% at doses of 25, 50 and 100 mg/kg, respectively). In the paw edema test, the EO (100 mg/kg) inhibited all three phases of the edema equally well, suggesting that the EO has a non-selective inhibitory effect on the release or actions of these mediators. Our results suggest possible antinociceptive and anti-inflammatory effects of the EO.

Organic and mineral fertilization and chemical composition of lemon balm (Melissa officinalis) essential oil

Melissa officinalis L., Lamiaceae, is an herb with great growth prospects in the cosmetic industry due to its essential oil. In order to improve its production, it is necessary to study related agricultural practices. This study evaluated the effect of organic and mineral fertilization on the chemical composition of lemon balm (Melissa officinalis L.) essential oil. The assay was conducted at the "Fazenda Experimental do Glória" of the Federal University of Uberlândia, and essential oil extraction and GC/MS analyses were completed by the Centre for Research and Development on Plant Genetic Resources of the Campinas Agronomic Institute. The assay was conducted in a randomized complete block design with three replications. The tested treatments were six types of fertilization (0, 1, 2, 4, 8 kg.m-2 of cattle manure and mineral fertilizing with 60 g.m-2 of NPK 4-14-8 + 4 g.m-2 of boric acid) with four replications. The essential oil was extracted by hydrodistillation in a modified Clevenger apparatus. The chemical composition was analyzed by GC/MS. The essential oil presented the same compounds for all treatments; however, the relative proportion of some chemical constituents was altered according to the treatment. Neral, geranial, and citronellal were the major constituents.

Leishmanicidal activity of carvacrol-rich essential oil from Lippia sidoides Cham.

Leishamaniasis is a disease that affects more than 2 million people worldwide, whose causative agent is Leishmania spp. The current therapy for leishmaniasis is far from satisfactory. All available drugs, including pentavalent antimony, require parenteral administration and are potentially toxic. Moreover, an increase in clinical resistance to these drugs has been reported. In this scenario, plant essential oils used traditionally in folk medicine are emerging as alternative sources for chemotherapeutic compounds. In this study, in vitro leishmanicidal effects of a thymol- and a carvacrol-rich essential oil from leaves of Lippia sidoides Cham. were investigated. The essential oils were extracted and their constituents were characterized by gas chromatography coupled to mass spectrometry (GC/MS). Both essential oils showed significant activity against promastigote forms of Leishmania chagasi. However, we found that carvacrol-rich essential oil was more effective, with IC50/72 h of 54.8 µg/mL compared to 74.1 µg/mL for thymol-rich oil. Carvacrol also showed lower IC50 than thymol. Our data suggest that L. sidoides essential oils are indeed promising sources of leishmanicidal compounds.

Leishmanicidal activity of carvacrol-rich essential oil from Lippia sidoides Cham

Leishamaniasis is a disease that affects more than 2 million people worldwide, whose causative agent is Leishmania spp. The current therapy for leishmaniasis is far from satisfactory. All available drugs, including pentavalent antimony, require parenteral administration and are potentially toxic. Moreover, an increase in clinical resistance to these drugs has been reported. In this scenario, plant essential oils used traditionally in folk medicine are emerging as alternative sources for chemotherapeutic compounds. In this study, in vitro leishmanicidal effects of a thymol- and a carvacrol-rich essential oil from leaves of Lippia sidoides Cham. were investigated. The essential oils were extracted and their constituents were characterized by gas chromatography coupled to mass spectrometry (GC/MS). Both essential oils showed significant activity against promastigote forms of Leishmania chagasi. However, we found that carvacrol-rich essential oil was more effective, with IC50/72 h of 54.8 μg/mL compared to 74.1 μg/mL for thymol-rich oil. Carvacrol also showed lower IC50 than thymol. Our data suggest that L. sidoides essential oils are indeed promising sources of leishmanicidal compounds.

Chemical composition and vasorelaxant effect induced by the essential oil of Lippia alba (Mill.) N.E. Brown. (Verbenaceae) in rat mesenteric artery.

OBJECTIVES: To investigate the chemical composition and vasorelaxant effect of the essential oil of Lippia alba (EOLA) in rat mesenteric artery. MATERIAL AND METHODS: Chemical composition of EOLA was investigated by gas chromatography-mass spectrometry (GC/MS). Vasorelaxant effect was evaluated in vitro in rat superior mesenteric artery rings. RESULTS: GC/MS analysis revealed the presence of 19 compounds, with geranial (48.58%) and neral (35.42%) being the major constituents. In intact rings precontracted with phenylephrine (Phe: 1 µM), EOLA (100-1000 µg/mL) induced relaxation, where the maximal effect (Emax) was 110.8 ± 10.8%. This effect was not modified after endothelium removal (Emax = 134.8 ± 16.5%), after tetraethylammonium (TEA) (Emax = 117.2 ± 4.96%), or in rings precontracted with KCl (80 mM) (Emax = 112.6 ± 6.70%). In addition, EOLA was able to inhibit the contraction caused by CaCl(2) and produced a small but significant (P<0.05) additional effect (from 70.5 ± 3.4 to 105.3 ± 13.5%, n = 5) on the maximal relaxation of nifedipine (NIF: 10 µM). CONCLUSIONS: The results demonstrated that EOLA induces endothelium-independent vasorelaxation, which appears to be caused, at least in part, by blocking Ca(2+) influx through voltage-operated Ca(2+) channels.

Characterisation of the anti-inflammatory and antinociceptive activities and the mechanism of the action of Lippia gracilis essential oil.

ETHNOPHARMACOLOGICAL RELEVANCE: The species Lippia gracilis Schauer, known in Brazil as "Alecrim-da-chapada", is popularly used in folk medicine to treat cough, bronchitis, nasal congestion, and headache. MATERIALS AND METHODS: Lippia gracilis essential oil (EO; 10, 30, and 100mg/kg, p.o.) and the reference drugs morphine (5mg/kg, p.o.) and acetylsalicylic acid (ASA; 200mg/kg, p.o.) were evaluated using models for analgesia (acetic acid-induced contortion, formalin-induced licking, and hot plate) or inflammation (formalin-induced licking response and subcutaneous air pouch model). To elucidate the antinociceptive mechanism of action, animals were pre-treated with naloxone (opioid receptor antagonist; 1mg/kg, i.p.), atropine (cholinergic antagonist; 1mg/kg, i.p.) or l-nitro arginine methyl ester (L-NAME; 3mg/kg, i.p.) 30 min prior to oral administration of EO. RESULTS: EO significantly inhibited the number of writhings in acetic acid-induced contortions and the time that the animal spent licking the formalin-injected paw (second phase). All doses of EO increased the baseline and the area under the curve in the hot plate model. The administration of naloxone did not reverse the antinociceptive effect of EO in the acetic acid-induced contortion and formalin-induced licking models. L-NAME and atropine significantly reversed the effect of EO in the models of contortion, formalin, and hot plate. EO also inhibited the inflammatory process induced by subcutaneous carrageenan injection, reducing cell migration, exudate volume, extravased protein, and inflammatory mediators (nitric oxide, prostaglandin E2, TNF-α, and IFN-γ) produced in the pouch. CONCLUSIONS: Our results indicate that the essential oil from Lippia gracilis produces an antinociceptive effect that could be potentially mediated by cholinergic receptors and the nitric oxide pathway. Our data also suggest that the anti-inflammatory activity caused by EO exposure occurs through inhibition of nitric oxide and PGE2 production.

Chemical composition and cardiovascular effects induced by the essential oil of Cymbopogon citratus DC. Stapf, Poaceae, in rats / Composição química e efeitos cardiovasculares do óleo essencial de Cymbopogon citratus DC. Stapf, Poaceae, em ratos

Cymbopogon citratus DC. Stapf, Poaceae, is used in the folk medicine for hypertension treatment. This work investigated the chemical composition and cardiovascular effects in rats of C. citratus essential oil (EOCC). A phytochemical screening demonstrated the presence of eight constituents, being geranial the major compound (43.08 percent). In rats, EOCC (1, 5, 10, and 20 mg/kg, i.v.) induced transient hypotension and bradycardia that were attenuated by atropine and sodium thiopental, but not by L-NAME or indomethacin. In rings of rat superior mesenteric artery pre-contracted with phenylephrine, EOCC (1 to 3000 µg/mL) induced relaxation that was not affected after removal of the endothelium, after TEA or in rings pre-contracted with KCl (80 mM). Furthermore, EOCC (1000 µg/mL) was not able to induce additional effect on maximal relaxation of nifedipine (10 µM). In conclusions, EOCC induces hypotension, possibly by reduction in vascular resistance caused by inhibition of the Ca2+ influx, and bradycardia probably due to an activation of cardiac muscarinic receptors.

C. citratus é utilizada na medicina popular para tratar hipertensão. Este trabalho investigou a composição química e os efeitos cardiovasculares do óleo essencial do C. citratus (OECC). Foram identificados oito constituintes no OECC, sendo geranial o majoritário (43,08 por cento). Em ratos, o OECC (1, 5, 10 e 20 mg/kg, i.v.) induziu hipotensão e bradicardia que foram atenuadas pela atropina e tiopental sódico, mas não por L-NAME ou indometacina. Em anéis de artéria mesentérica de ratos pré-contraídos com fenilefrina, o OECC (1 a 3000 µg/mL) induziu relaxamento que não foi afetado após remoção do endotélio, após TEA ou em anéis pré-contraídos com KCl (80 mM). Além disso, o OECC (1000 µg/mL) não induziu efeito adicional sobre o relaxamento máximo da nifedipina (10 µM). Em conclusão, o OECC induz hipotensão possivelmente devido à redução da resistência vascular que pode ser causada por inibição do influxo de Ca2+, e bradicardia provavelmente devido à ativação de receptores muscarínicos cardíacos.

Assessment of antinociceptive, anti-inflammatory and antioxidant properties of Cymbopogon winterianus leaf essential oil.

The present study investigated the antinociceptive, anti-inflammatory and antioxidant effects of the leaf essential oil (LEO) of Cymbopogon winterianus Jowitt (Poaceae). In the acetic acid-induced writhing and formalin tests, the LEO (50, 100, and 200 mg/kg, p.o.) significantly reduced (p < 0.05) the number of writhings and paw licking times in the first (0-5 min) and second (15-30 min) phases, respectively. In contrast, the LEO did not alter the latency time for mice licking the rear paws in hot-plate test. The LEO inhibited the carrageenan-induced neutrophil migration to the peritoneal cavity in a dose-dependent manner (35.5%, 42.8%, and 66.1% at doses of 50, 100, and 200 mg/kg, respectively, p < 0.001). Moreover, LEO exhibited higher scavenging activity toward 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals with an IC(50) (12.66 ± 0.56 µg/mL). Our present results demonstrated that the LEO has antinociceptive, anti-inflammatory, and antioxidant properties.

Influence of season, harvest time and drying on Java citronella (Cymbopogon winterianus Jowitt) volatile oil

Java citronella (Cymbopogon winterianus Jowitt) is member of the Poaceae family. Java citronella volatile oil has been reported to be among the volatile oils, showing repellent, antimycotic, and acaricide activities. It has been known that agronomical factors have a great effect on both the quality and quantity of essential metabolites. For this reason, it is necessary to determine optimum levels of agronomical factors affecting plant growth and production. Harvest time and drying are very important agronomical factors. This study has been conducted in the Research farm of the " Universidade Federal de Sergipe" , Agronomical Engineering Department along 2002-2003 on the base of factorial experiment in randomized complete block design with three replications. Java citronella was cultivated in a 60 x 60 cm space. Early, midday, and late harvest at 9:00 h, 12:00 h, and 15:00 h were conducted on four different seasons. Fresh and dried leaves were used on the experiments. In order to study the effects of harvest time and drying, yields of dry and fresh herbage (kg/ha), moisture content ( percent), volatile oil content ( percent) and yield (L/ha), and chemical composition of the volatile oil were measured. Seasonal changes had significant effect on yield of fresh herbage, yield and volatile oil content. Maximum volatile oil yields were observed at 9:00 during summer, winter, and spring. Volatile oil content was influenced by season and drying, but not influenced by harvest time.

Citronela de Java (Cymbopogon winterianus Jowitt) pertence à família Poaceae. Óleo volátil de citronela de Java apresenta atividade repelente, antimicrobiana e acaricida. Sabe-se que fatores agronômicos têm grande efeito sobre a qualidade e quantidade de metabólitos essenciais. Por isso é importante a determinação dos níveis ótimos dos fatores agronômicos que afetem o crescimento e a produção. Horário de colheita e secagem são fatores agronômicos muito importantes. O presente estudo foi conduzido na Fazenda Experimental do Departamento de Engenharia Agronômica da Universidade Federal de Sergipe, no período de 2002-2003, usando o delineamento de blocos casualizados e um experimento em esquema fatorial com três repetições. O capim citronela foi cultivado usando espaçamento de 60 cm entre linhas e 60 cm entre plantas. Realizaram-se colheitas de manhã, meio dia e à tarde, às 9:00 h, 12:00 h e 15:00 h, nas quatro estações do ano. Usaram-se folhas frescas e secas no experimento. Para estudar os efeitos do horário de colheita e secagem avaliaram-se as seguintes características: rendimento de biomassa seca e fresca (kg/ha), umidade ( por cento), teor ( por cento) e rendimento (L/ha) de óleo essencial, e a composição química do óleo essencial. Mudanças sazonais apresentaram efeito significativo sobre o rendimento de biomassa fresca e seca, e teor e rendimento de óleo. Rendimentos máximos de óleo essencial foram observados às 9:00 h durante o verão, inverno e primavera. O teor de óleo essencial foi influenciado pela estação doa ano e secagem, mas não foi influenciado pelo horário de colheita.