Preparation and Antibacterial Activity of Thermo-Responsive Nanohydrogels from Qiai Essential Oil and Pluronic F108.

Essential oils (EOs) have been used in cosmetics and food due to their antimicrobial and antiviral effects. However, the applications of EOs are compromised because of their poor aqueous solubility and high volatility. Qiai (Artemisia argyi Levl. et Van. var. argyi cv. Qiai) is a traditional Chinese herb and possesses strong antibacterial activity. Herein, we report an innovative formulation of EO as nanohydrogels, which were prepared through co-assembly of Qiai EO (QEO) and Pluronic F108 (PEG-b-PPG-b-PEG, or PF108) in aqueous solution. QEO was efficiently loaded in the PF108 micelles and formed nanohydrogels by heating the QEO/PF108 mixture solution to 37 °C, by the innate thermo-responsive property of PF108. The encapsulation efficiency and loading capacity of QEO reached 80.2% and 6.8%, respectively. QEO nanohydrogels were more stable than the free QEO with respect to volatilization. Sustained QEO release was achieved at body temperature using the QEO nanohydrogels, with the cumulative release rate reaching 95% in 35 h. In vitro antibacterial test indicated that the QEO nanohydrogels showed stronger antimicrobial activity against S. aureus and E. coli than the free QEO due to the enhanced stability and sustained-release characteristics. It has been attested that thermo-responsive QEO nanohydrogels have good potential as antibacterial cosmetics.

Investigation on the Epoxidation of Piperitenone, and Structure-activity Relationships of Piperitenone Oxide for Differentiation-inducing Activity.

Piperitenone oxide, a major chemical constituent of the essential oil of spearmint, Mentha spicata, induces differentiation in human colon cancer RCM-1 cells. In this study, piperitenone oxide and trans-piperitenone dioxide were prepared as racemic forms by epoxidation of piperitenone. The relative configuration between two epoxides in piperitenone dioxide was determined to be trans by 1H NMR analysis and nuclear Overhauser effect spectroscopy (NOESY) in conjunction with density functional theory (DFT) calculations. Optical resolution of (±)-piperitenone oxide by high-performance liquid chromatography (HPLC) using a chiral stationary phase (CSP) afforded both enantiomers with over 98% enantiomeric excess (ee). Evaluation of the differentiation-inducing activity of the synthetic compounds revealed that the epoxide at C-1 and C-6 in piperitenone oxide is important for the activity, and (+)-piperitenone oxide has stronger activity than (-)-piperitenone oxide. The results obtained in this study provide new information on the application of piperitenone oxide and spearmint for differentiation-inducing therapy. Furthermore, natural piperitenone oxide was isolated from M. spicata. The enantiomeric excess of the isolated natural piperitenone oxide was 66% ee. Epoxidation of piperitenone with hydrogen peroxide proceeded in a phosphate buffer under weak basic conditions to give (±)-piperitenone oxide. These results suggest that the nonenzymatic epoxidation of piperitenone, which causes a decrease in the enantiomeric excess of natural piperitenone oxide, is accompanied by an enzymatic epoxidation in the biosynthesis of piperitenone oxide.

Synthesis of Carum Carvi essential oil nanoemulsion, the cytotoxic effect, and expression of caspase 3 gene.

Scientists are attempting to find novel methods to overcome cancers. Nanoemulsion systems as the novel drug delivery tools have been widely used in cancer therapy. In this study, the Carum Carvi oil nanoemulsions (CCONE) were prepared and its cytotoxic activity was studied on human colon cancer HT-29 cells using MTT assay. Flow cytometry and Real-time qPCR were triggered to evaluate the nanoemulsions' apoptotic properties. The results showed a significant negative association between the HT-29 cancer cell viability and CCONE doses of treatments compared with Huvec normal cells (p value < 0.001). The IC50 values were estimated 12.5 µg/ml and 50 µg/ml for HT-29 and Huvec, respectively. Moreover, we observed that increasing concentrations of nanoemulsions significantly upregulate Caspase-3 gene expression. The results showed the CCONE is an efficient novel apoptosis inducer for human colon cancer cells without any undesirable side effects. However, further in vitro and in vivo researches are required. PRACTICAL APPLICATIONS: Cancer is a complex and usually untreatable disorder. Several types of cancer therapy strategies have been applied widely to overcome cancers. Chemotherapy has been used in various types of cancers. In most cases, not only it had not been effective on cancer cells but also been distractive within normal tissues. According to results, Carum Carvi essential oil nanoemulsions have apoptotic and cytotoxic effects on colon cancer cells (HT-29). When it comes to cancer of any kind, it's important to realize that no dietary supplement can fully treat, cure, or prevent cancer. However, there are some supplements that can potentially decrease the risk of cancer. Nanoemulsions present several advantages including the ability to incorporate hydrophilic, amphiphilic, and lipophilic excipient ingredients, high physical stability, and rapid gastrointestinal digestibility. The Carum Carvi essential oil nanoemulsion can also be applied as an effective food supplement due to its potent apoptotic activity.

In vitro and in vivo efficacy of tea tree essential oil for bacterial and yeast ear infections in dogs / Uso in vitro e in vivo do óleo essencial de Melaleuca (Melaleuca alternifolia) em otites bacterianas e por leveduras

Otitis externa is a common complaint in dogs. Bacteria and yeasts are commonly involved and may perpetuate inflammatory reactions inside the ear canal. Otoscopy, cytological examination of secretion and microbiological culture embody forms of diagnosis. Cytology also has great use in accessing treatment evolution. Therapy usually consists of cleaning ear canals and subsequent use of antibiotics or antifungal products. As some of them may cause hypersensitivity and even ototoxicity, searching for new pharmacological bases is currently necessary and justifies this study, which aimed to evaluate in vitro and in vivo efficacy of tea tree essential oil for bacterial and yeast ear infections in dogs. Twenty-eight dogs from a particular shelter in Cuiabá (Mato Grosso, Brazil), presenting clinical signs of otitis externa, were enrolled in this clinical trial. In all of them, clinical and cytological evaluations, as well as culture and susceptibility testing of the affected ears were carried out. From each dog, one ear was treated with 5% tea tree essential oil lotion and the other with standard otic formulation, according to the type of infection (bacterial, yeast or both). In vitro susceptibility testings of all ear cultures, to the same drugs used in treatment, were also carried out. Culture results showed 62.5% bacterial and fungal infection, 33.9% bacterial infection and 3.6% fungal infection, from the 56 ear samples collected. The most common microorganisms isolated were Staphylococcus intermedius, Staphylococcus aureus, Proteus mirabilis and Malassezia pachydermatis. Gram-positive bacteria were susceptible to gentamycin in 60.5% and resistant in 16.3% of the samples. Five percent tea tree essential oil formulation produced a 5mm clear zone of inhibition around the disks in one of the 63 samples evaluated. Pure (100%) tea tree essential oil formulation produced a 10mm clear zone of inhibition around the disks in four of the 63 samples evaluated, a 9mm zone in three samples, an 8mm zone in 16 samples, a 7mm zone in seven samples, a 6mm zone in two samples and there was no clear zone in 31 samples. Inhibition zones were produced by strains of Staphylococcus intermedius, Staphylococcus hyicus, Corynebacterium sp., Proteus mirabilis and Enterobacter sp. tea tree essential oil ear solution significantly induced remission of clinical signs both in bacterial and yeast ear infections. It also reduced as much Malassezia pachydermatis ear infection as the nystatin solution used in this study, while gentamycin solution showed better antibacterial effect. More studies should be conducted to evaluate in vitro diffusion properties of tea tree essential oil. Good antimicrobial spectrum and the absence of adverse reactions confirm the importance of developing a tea tree formulation as an alternative therapy for ear infections in dogs.(AU)

Otite externa é queixa frequente em cães. Bactérias e leveduras estão comumente envolvidas e podem perpetuar as reações inflamatórias dentro do canal auditivo. Dentre as formas de diagnóstico, encontram-se a otoscopia, o exame citológico da secreção e a cultura microbiológica. Citologia também tem grande utilidade no acesso à evolução do tratamento. A terapia consiste de limpeza dos canais auditivos e posterior utilização de antibióticos ou produtos antifúngicos. Como alguns antimicrobianos utilizados no tratamento podem causar hipersensibilidade e até mesmo ototoxicidade, a busca por novas bases farmacológicas justifica a existência deste estudo, que teve como objetivo avaliar in vitro e in vivo a eficiência do óleo de Melaleuca alternifolia em otites bacterianas e fúngicas de cães. Vinte e oito cães, de um abrigo particular, apresentando sinais clínicos de otite externa, foram incluídos neste estudo clínico. Todos passaram por avaliação clínica, citologia e cultura de material das orelhas afetadas. De cada animal, uma orelha foi tratada com óleo de Melaleuca 5% e a outra com formulação ótica padrão, de acordo com a afecção (bacteriana, fúngica ou mista). As culturas também foram submetidas a testes de susceptibilidade in vitro aos mesmos agentes utilizados no tratamento in vivo. Os resultados da cultura mostraram 62,5% de infecção mista (bacteriana e fúngica), 33,9% de infecção bacteriana e 3,6%, de infecção fúngica a partir das 56 orelhas. Os micro-organismos mais isolados foram Staphylococcus intermedius, Staphylococcus aureus, Proteus mirabilis e Malassezia pachydermatis. As bactérias GRAM-positivas foram sensíveis à gentamicina em 60,5% e resistentes em 16,3% das amostras. A formulação com 5% de óleo essencial de Melaleuca produziu uma zona de inibição de 5mm em torno dos discos em uma das 63 amostras avaliadas. A formulação pura (100%) do mesmo produto produziu uma zona de 10mm de inibição em quatro das 63 amostras analisadas, uma zona de 9 mm em três amostras, uma zona de 8mm em 16 amostras, uma zona de 7mm em sete amostras, uma zona de 6mm em duas amostras e não havia nenhuma zona clara em 31 amostras. Zonas de inibição foram produzidas por estirpes de Staphylococcus intermedius, Staphylococcus hyicus, Corynebacterium sp., Proteus mirabilis e Enterobacter sp. Clinicamente, a formulação com o óleo essencial de melaleuca induziu significativamente uma melhora nas manifestações, tanto nas otites bacterianas quanto nas causadas por leveduras, sendo estatisticamente semelhante ao tratamento com nistatina (nas otites por levedura), mas menos eficaz que a solução de gentamicina nas otites bacterianas. Mais estudos devem ser realizados para avaliar as propriedades de difusão in vitro do óleo essencial de melaleuca. O bom espectro antimicrobiano, a boa resposta clínica e a ausência de reações adversas confirmam a possibilidade de desenvolvimento de formulação ótica com o óleo essencial de melaleuca, como uma alternativa para a terapia de infecções do ouvido em cães.(AU)

Effect of essential oil and surfactant on the physical and antimicrobial properties of corn and wheat starch films.

The present study describes the microstructure, physical (tensile strength, elongation at break, water-vapor permeability, optical characteristics) and antimicrobial properties of biodegradable films prepared by incorporating different concentrations of lemon essential oil (LO) and surfactants (Span 80, Tween 80) into corn and wheat (CW) starch film. Results showed that the incorporation of LO provoked a decrease in water content, transparency, whiteness index (WI), water vapor permeability (WVP), solubility and tensile strength properties. Higher b*, elongation and haze values were observed in CW-LO composite films. Films with LO, especially at higher concentrations, were more effective against all tested bacteria than the control films. The films' surface and cross-section morphology was different depending on the LO contents. Compared with the CW-1LO film, the addition of surfactants significantly increased antimicrobial activity, solubility, haze, surface coarseness and porosity; remarkably decreased tensile strength and transparency. The film containing only Tween 80 showed higher b*, water content, solubility and WVP, lower WI and elongation when compared with the film containing only Span 80. These properties with some good physical and antimicrobial characteristics suggest applications for CW-LO-T/S film in a wide range of food products.

Arthropod Deterrents from Artemisia pallens (Davana Oil) Components.

Davanone, a key sesquiterpene component of davana oil, has been synthesized in five convenient steps. Oxygenated sesquiterpenes have been linked to insect deterrent properties. Based on initial screening of davana oil, davanone and its hydroxy precursors have been generated and are being evaluated as arthropod deterrents against disease vectors.

Cytotoxic and antibacterial activities of the analogues of pogostone.

Six new (A5-A6, A8-A11) and six known (A1-A4, A7, PO) α-pyrone compounds were synthesized with dehydroacetate and aldehydes in tetrahydrofuran at room temperature. And their structures were determined by (1)H-NMR, (13)C-NMR and mass spectroscopy. In the bioscreening experiments, ten compounds (A1-A5, PO, A7-A10) exhibited antibacterial activities against Staphylococcus aureus ATCC 25923 with minimum inhibitory concentration (MIC) values of 4-512 mg/L, and nine compounds (A1-A5, PO, A7-A8, A10) exhibited antibacterial activities against Methicillin-resistant S. aureus (MRSA) ATCC 43300 with MIC values of 4-256 mg/L. Moreover, compound A10 showed the highest antibacterial activity against S. aureus ATCC 25923 and MRSA with MIC values of 4 mg/L, while the MIC values of Amoxicillin were 8 mg/L and >256 mg/L, respectively. Two compounds (A8 and PO) exhibited antibacterial activities against Escherichia coli ATCC 25922 with MIC values of 32-512 mg/L. However, only one compound (A8) exhibited significant antibacterial activity against Pseudomonas aeruginosa CVCC 3360 with MIC value of 256 mg/L. Moreover, A10 exhibited significant inhibition of proliferation in the four cell lines MCF-10, A549, A2780 and MFC, and showed stronger inhibitive activity of these four selected cell lines than cisplatin in the cytotoxic assay. Thus, this study suggests that pogostone analogues, especially A10, represented a kind of promising antibacterial and antineoplastic agents.

Efeitos de diferentes tempos de extração no teor e composição química do óleo essencial de folhas de pariparoba [Pothomorphe umbellata (L. ) Miq. ] / Effects of time of extraction in the yield and chemical composition of the essential oil of pariparoba leaves [Pothomorphe umbellata (L. Miq. ]

O presente trabalho visou avaliar a influência de diferentes tempos de extração no teor e composição química do óleo essencial da espécie Pothomorphe umbellata. Folhas de pariparoba foram coletadas em Cajamar - SP, no mês de junho de 2006. O delineamento experimental adotado foi inteiramente casualizado, com seis tempos de extração (90, 120, 150, 180, 210 e 240 minutos) e 4 repetições. A extração do óleo essencial foi realizada por hidrodestilação e a análise química em CG-EM. O tempo de 180 minutos proporcionou maior rendimento do óleo essencial (0,42%), enquanto a composição química não foi influenciada pelos diferentes tempos de destilação. As principais substâncias identificadas foram: D-germacreno (65,5%), alfa-selineno (9,7%), trans-cariofileno (7,5%), e espatulenol (6,58%). Conclui-se que o tempo de extração afeta diretamente o rendimento e a proporção das substâncias químicas, recomendando-se a extração em até 180 minutos. .

The present work aimed to evaluate the influence of different times of extraction in the yield and chemical composition of the essential oil of "pariparoba" (Pothomorphe umbellate). Leaves of "pariparoba" were collected in the municipal district of Cajamar - state of São Paulo, Brazil, in June 2006. The adopted experimental design was completely randomized, with six times of extraction (90, 120, 150, 180, 210, and 240 minutes) and 4 repetitions. The extraction of the essential oil was accomplished by hydrodistillation, and the chemical analysis was performed in GC-MS. The time of extraction of 180 minutes provided greater yield of the essential oil (0.42%), and its chemical composition was not influenced by the different times of hydrodistillation. The main substances showed are D-germacrene (65.5%), alpha-selinene (9.7%), trans-caryophyllene (7.5%) and spathulenol (6.58%). The results of this work showed that the time of extraction affects the yield and the proportion of the chemical substances and it is recommended the extraction in up to 180 minutes.

Novel glycolipids synthesized using plant essential oils and their application in quorum sensing inhibition and as antibiofilm agents.

Essential oils (EOs) form an important part of traditional medicine so their anti-microbial and, in the recent past, antiquorum sensing activity has been well studied. However it is likely that due to their hydrophobic nature and reduced solubility in aqueous environments full potential of their activity cannot be realized. hence it is only rational to formulate a process to make these molecules more polar in nature. The present paper reports synthesis of sophorolipids using 12 different essential oils as substrates, thus providing surfactant-like properties to these EOs. The synthesis protocol makes the use of Candida bombicola ATCC 22214 as producer organism. The production process required 7 days of incubation at 28°C and 180 rpm. Preliminary characterization of the synthesized essential oil sophorolipids (EOSLs) was performed using thin layer chromatography (TLC) and Fourier transform infrared spectroscopy (FTIR). Additionally, essential oils that were incapable of mediating quorum sensing inhibition (QSI) on their own became potent quorum sensing inhibitors upon conversion into their corresponding EOSLs. Antibiofilm potential of these EOSLs was also demonstrated using V. cholerae as test organism. Use of essential oils as substrates for glycolipid synthesis has not been attempted previously, and hence this is the first report.

Antioxidant activity of essential oils.

Essential oils (EOs) are liquid mixtures of volatile compounds obtained from aromatic plants. Many EOs have antioxidant properties, and the use of EOs as natural antioxidants is a field of growing interest because some synthetic antioxidants such as BHA and BHT are now suspected to be potentially harmful to human health. Addition of EOs to edible products, either by direct mixing or in active packaging and edible coatings, may therefore represent a valid alternative to prevent autoxidation and prolong shelf life. The evaluation of the antioxidant performance of EOs is, however, a crucial issue, because many commonly used "tests" are inappropriate and give contradictory results that may mislead future research. The chemistry explaining EO antioxidant activity is discussed along with an analysis of the potential in food protection. Literature methods to assess EOs' antioxidant performance are critically reviewed.

Synthesis and antimicrobial evaluation of pogostone and its analogues.

Pogostone (PO) is one of the secondary metabolites from Pogostemon cablin (Blanco) Benth. (Lamiaceae), serving as the effective component of the antimicrobial activity. In this study, PO and a series of its analogues were synthesized by the reaction of dehydroacetate and aldehydes in tetrahydrofuran under a nitrogen atmosphere. Their activities against Candida albicans, Gram positive bacteria and Gram negative bacteria were evaluated. The antifungal results demonstrated that PO (MIC ranged from 12 to 97µg/mL against all strains, MFC ranged from 49 to 97µg/mL against all strains) and A3 (MIC ranged from 12 to 49, MFC over 195µg/mL) showed a strong activity against Candida albicans. While A1 (MIC ranged from 49 to 97µg/mL) and A2 (MIC ranged from 24 to 49µg/mL) have only shown effect against Guangzhou clinical isolates, the antibacterial results demonstrated that PO and its analogues showed no effects against the tested bacteria strains. This study suggests that pogostone analogues, with the appropriated structure modification, represented a kind of promising antifungal agents.

Chemical composition and antimicrobial activity of the essential oil from the leaves and flowers of Aloysia gratissima / Composição química e atividade antimicrobiana do óleo essencial de folhas e flores de Aloysia gratissima

Volatile oils from leaves and flowers of Aloysia gratissima were investigated for their chemical composition and antimicrobial activity against the bacteria Bacilus subtilis, Staphylococcus aureus, Salmonella choleraesuis, Pseudomonas aeruginosa, Streptococcus pneumoniae and the Candida albicans yeast. The minimum inhibitory concentrations (MIC) of the oils were determined by the micro-dilution method, while the chemical composition was determined by GC-MS (gas chromatography mass spectrometry). The fresh leaves and inflorescence were subjected to hydrodistillation for 120 min using a Clevenger-type apparatus, and the essential oil was tested against microorganisms. High concentrations of sesquiterpenes were observed for the inflorescence, and monoterpenes were observed for the leaves. The main compounds of the inflorescence essential oil were E-caryophyllene, germacrene B, guaiol and bulnesol, while in the leaves the main compounds were trans-pinocamphone, trans-pinocarveyl acetate, and guaiol. The essential oil from the leaves showed an effect against P. aeruginosa and S. pneumonia, and the essential oil of the inflorescence showed an effect against P. aeruginosa, S. pneumonia, and Candida albicans.

O óleo essencial de folhas e de flores de Aloysia gratissima foi avaliado quanto à composição química e ação antimicrobiana contra as bactérias Bacilus subtilis, Staphylococcus aureus, Salmonella choleraesuis, Pseudomonas aeruginosa, Streptococcus pneumoniae, e a levedura Candida albicans. A concentração mínima inibitória (MIC) dos óleos essenciais foi determinada pelo método da microdiluição e a composição química determinada por CG-EM (Cromatografia Gasosa acoplada a Espectrômetro de Massas). Folhas e inflorescências frescas foram hidrodestiladas por 120 minutos em aparelho Clevenger sendo o óleo essencial testado contra microorganismos. Para as flores foi observada maior concentração de sesquiterpenos, enquanto que as folhas apresentaram maior concentração de monoterpenos. Os principais constituintes do óleo essencial da flor foram: E-cariofileno, germacreno B, guaiol e bulnesol; e das folhas foram: trans-pinocamfona, acetato de trans-pinocarveol e guaiol. O óleo essencial da folha mostrou atividade contra P. aeruginosa e S. pneumoniae, e o óleo essencial da flor mostrou atividade contra P. aeruginosa, S. pneumoniae e Candida albicans.

Composição química e atividade inseticida do óleo essencial de Schinus terebinthifolius Raddi (Anacardiaceae) sobre a broca-do-café (Hypothenemus hampei) Ferrari / Chemical composition and insecticidal activity of the essential oil of Schinus terebinthifolius Raddi (Anacardiaceae) on coffee berry borer (Hypothenemus hampei) Ferrari

O óleo essencial das folhas de Schinus terebinthifolius foi obtido por hidrodestilação e analisado por CG-EM. O rendimento do óleo foi de 0,8%, sendo identificados 37 constituintes químicos. Os componentes principais foram germacreno D (25,0%), (E)-ß-cariofileno (17,5%) e δ -elemeno (10,5%). O óleo essencial foi diluído em acetona nas concentrações de 10-2 a 10-8 e aplicado aos insetos (Hypothenemus hampei) por aplicação tópica e exposição em superfície contaminada. As taxas de mortalidade foram avaliadas após 24 e 48 horas do início do experimento. A aplicação em superfície contaminada resultou em 25% de mortalidade no controle, enquanto nas diluições de 10-2 a 10-8 foram observados 100,0 a 30,0% de mortalidade. Na aplicação tópica, observou-se 27,5% de mortalidade no controle e 97,5 a 77,5% nas diluições de 10-2 a 10-8.

The essential oil from the leaves of Schinus terebinthifolius was obtained by hydrodistillation and was analyzed by GC-MS. The oil yield was 0.8%, and 37 chemical constituents were identified. The main components were germacrene D (25.0%), (E)-ß-cariophyllene (17.5%) and δ-elemene (10.5%). The essential oil was diluted in acetone in concentrations of 10-2 to 10-8 and it was applied to insects (Hypothenemus hampei) by topical application and exposure to contaminated surface. Mortality rates were evaluated after 24 and 48 hours. The contaminated surface application resulted in 25.0% of mortality in control while the dilutions of 10-2 to 10-8 resulted in 100% to 30.0% of mortality respectively. In the topical application, it was observed 27.5% of mortality in control and 97.5 to 77.5% of mortality in dilutions of 10-2 to 10-8

Plant extracts, isolated phytochemicals, and plant-derived agents which are lethal to arthropod vectors of human tropical diseases--a review.

The recent scientific literature on plant-derived agents with potential or effective use in the control of the arthropod vectors of human tropical diseases is reviewed. Arthropod-borne tropical diseases include: amebiasis, Chagas disease (American trypanosomiasis), cholera, cryptosporidiosis, dengue (hemorrhagic fever), epidemic typhus (Brill-Zinsser disease), filariasis (elephantiasis), giardia (giardiasis), human African trypanosomiasis (sleeping sickness), isosporiasis, leishmaniasis, Lyme disease (lyme borreliosis), malaria, onchocerciasis, plague, recurrent fever, sarcocystosis, scabies (mites as causal agents), spotted fever, toxoplasmosis, West Nile fever, and yellow fever. Thus, coverage was given to work describing plant-derived extracts, essential oils (EOs), and isolated chemicals with toxic or noxious effects on filth bugs (mechanical vectors), such as common houseflies (Musca domestica Linnaeus), American and German cockroaches (Periplaneta americana Linnaeus, Blatella germanica Linnaeus), and oriental latrine/blowflies (Chrysomya megacephala Fabricius) as well as biting, blood-sucking arthropods such as blackflies (Simulium Latreille spp.), fleas (Xenopsylla cheopis Rothschild), kissing bugs (Rhodnius Stål spp., Triatoma infestans Klug), body and head lice (Pediculus humanus humanus Linnaeus, P. humanus capitis De Geer), mosquitoes (Aedes Meigen, Anopheles Meigen, Culex L., and Ochlerotatus Lynch Arribálzaga spp.), sandflies (Lutzomyia longipalpis Lutz & Neiva, Phlebotomus Loew spp.), scabies mites (Sarcoptes scabiei De Geer, S. scabiei var hominis, S. scabiei var canis, S. scabiei var suis), and ticks (Ixodes Latreille, Amblyomma Koch, Dermacentor Koch, and Rhipicephalus Koch spp.). Examples of plant extracts, EOs, and isolated chemicals exhibiting noxious or toxic activity comparable or superior to the synthetic control agents of choice (pyrethroids, organophosphorous compounds, etc.) are provided in the text for many arthropod vectors of tropical diseases.

Patent literature on mosquito repellent inventions which contain plant essential oils--a review.

Bites Bites of mosquitoes belonging to the genera Anopheles Meigen, Aedes Meigen, Culex L. and Haemagogus L. are a general nuisance and are responsible for the transmission of important tropical diseases such as malaria, hemorrhagic dengue and yellow fevers and filariasis (elephantiasis). Plants are traditional sources of mosquito repelling essential oils (EOs), glyceridic oils and repellent and synergistic chemicals. A Chemical Abstracts search on mosquito repellent inventions containing plant-derived EOs revealed 144 active patents mostly from Asia. Chinese, Japanese and Korean language patents and those of India (in English) accounted for roughly 3/4 of all patents. Since 1998 patents on EO-containing mosquito repellent inventions have almost doubled about every 4 years. In general, these patents describe repellent compositions for use in topical agents, cosmetic products, incense, fumigants, indoor and outdoor sprays, fibers, textiles among other applications. 67 EOs and 9 glyceridic oils were individually cited in at least 2 patents. Over 1/2 of all patents named just one EO. Citronella [Cymbopogon nardus (L.) Rendle, C.winterianus Jowitt ex Bor] and eucalyptus (Eucalyptus LʼHér. spp.) EOs were each cited in approximately 1/3 of all patents. Camphor [Cinnamomum camphora (L.) J. Presl], cinnamon (Cinnamomum zeylanicum Blume), clove [Syzygium aromaticum (L.) Merr. & L.M. Perry], geranium (Pelargonium graveolens LʼHér.), lavender (Lavandula angustifolia Mill.), lemon [Citrus × limon (L.) Osbeck], lemongrass [Cymbopogon citratus (DC.) Stapf] and peppermint (Mentha × piperita L.) EOs were each cited in > 10% of patents. Repellent chemicals present in EO compositions or added as pure "natural" ingredients such as geraniol, limonene, p-menthane-3,8-diol, nepetalactone and vanillin were described in approximately 40% of all patents. About 25% of EO-containing inventions included or were made to be used with synthetic insect control agents having mosquito repellent properties such as pyrethroids, N,N-diethyl-m-toluamide (DEET), (±)-p-menthane-3,8-diol (PMD) and dialkyl phthalates. Synergistic effects involving one or more EOs and synthetic and/or natural components were claimed in about 10% of all patents. Scientific literature sources provide evidence for the mosquito repellency of many of the EOs and individual chemical components found in EOs used in patented repellent inventions.

Los aceites esenciales como agentes antiparasitarios / Essential oils as anti-parasitic agents

La aparición de parásitos resistentes a la terapia, incluyendo protozoos de géneros como Leishmania, Trypanossoma, Giardia y Plasmodium, y/o la falta de eficacia, los efectos secundarios graves y el alto costo de la terapia, hace urgente desarrollar nuevos agentes antiparasitarios. En los últimos años se ha potenciado la búsqueda de nuevos medicamentos alternativos para el tratamiento de las infecciones por parásitos, habiendo aumentado el descubrimiento de potenciales agentes terapéuticos a partir de fuentes naturales como las plantas medicinales y sus extractos, incluyendo los aceites esenciales. Aceites esenciales, tales como los de Cymbopogon citratus, Croton cajucara, Ocimum gratissimum o Thymus vulgaris, han demostrado su actividad antiparasitaria, con un amplio espectro de actividad, a menudo demostrando eficacia equivalente a la quimioterapia establecida (AU)

The emergence of parasites resistant to therapy, namely protozoa of genera Leishmania, Trypanossoma, Giardia, Plasmodium, and/or the lack of efficacy, the occurrence of serious side effects and the high cost of therapy, makes urgent the development of new anti-parasitic agents. In the last years, the search for new alternative drugs for the treatment of parasitic infections have been developed. The discovery of potential therapeutic agents from natural sources such as medicinal plants and their extracts, including essential oils, has increased. Essential oils from Cymbopogon citratus, Croton cajucara, Ocimum gratissimum and Thymus vulgaris, showed anti-parasitic activity with a broad spectrum of activities and often demonstrating equivalent effectiveness to established chemotherapy (AU)

A emergência de parasitas resistentes à terapêutica instituída, designadamente protozoários de géneros como a Leishmania, Trypanossoma, Giardia, Plasmodium, e/ou a falta de eficácia, os efeitos secundários graves e o custo elevado, torna urgente o desenvolvimento de novos agentes anti-parasitários. Nos últimos anos, a pesquisa por fármacos novos e alternativos no tratamento de infecções por parasitas, tem vindo a desenvolver-se. A descoberta de potenciais agentes terapêuticos a partir de fontes naturais como as plantas medicinais e dos seus extractos, nomeadamente os óleos essenciais, tem vindo a aumentar. Os óleos essenciais como o Cymbopogon citratus, o Croton cajucara, o Ocimum gratissimum, ou o Thymus vulgaris, têm demonstrado actividade anti-parasitária com um amplo espectro de actividades evidenciando, muitas vezes, eficácia equivalente à quimioterapia padrão (AU)

Acetylcholinesterase inhibitory activity and chemical composition of commercial essential oils.

Commercially available essential oils extracted from Artemisia dracunculus L., Inula graveolens L., Lavandula officinalis Chaix, and Ocimum sanctum L. and the components of these oils were screened by the microplate assay method for determining their acetylcholinesterase (AChE) inhibitory activity. The composition profiles of the oils were characterized by gas chromatography-mass spectrometry (GC-MS) analysis, and the relationships between the oil components and the AChE inhibitory activity of the oils were outlined. The results showed that all of the oils, except that of A. dracunculus from Hungary, exhibited AChE inhibitory activity, and the A. dracunculus oil from France showed the most potent inhibitory activity [50% inhibition concentration (IC(50)) = 0.058 mg/mL]. The AChE inhibitory activity of I. graveolens oil has not been reported to date, and this study is the first to reveal this activity in the oil. Among the essential oil components, five components, namely, 1,8-cineole, α-pinene, eugenol, α-terpineol, and terpinen-4-ol, showed AChE inhibitory activity, with IC(50) values of 0.015, 0.022, 0.48, 1.3, and 3.2 mg/mL, respectively. Eugenol, in particular, was found to be a potent AChE inhibitor along with determination of the IC(50) value, a finding that has been reported for the first time in this study. However, the ratio of the contribution of the active components, including a novel AChE inhibitor, to the observed AChE inhibitory activity of the essential oils was not very high. The results of this study raise concerns about the AChE inhibitory activity of widely produced and readily accessible commercial essential oils.

Coactivity of sulfide ingredients: a new perspective of the larvicidal activity of garlic essential oil against mosquitoes.

BACKGROUND: The activity of several garlic oil ingredients against Culex pipiens L. larvae was studied. In addition to diallyl sulfide (DS) and diallyl disulfide (DDS), the garlic oils used included one essential oil (EO) and two semi-synthetic garlic essential oils (SSGEO1 and SSGEO2), which resulted from the enrichment of EO with DS and DDS standards respectively. The oils were compared with respect to their toxicity. RESULTS: The chemical composition of the tested oils was evaluated by means of gas chromatography-mass spectrometry. Experimental data from the tested samples revealed high toxicity. In detail, DDS (6.09 mg L(-1)) was the most active, followed by SSGEO2 (7.05 mg L(-1)) and EO (8.01 mg L(-1)), while SSGEO1 and DS were relatively inactive. CONCLUSION: The addition of DDS to EO did not change the toxic effect of the essential oil, whereas the presence of DS in excess produced an enriched essential oil with low toxicity. Furthermore, the antagonistic effect of DS and DDS against the other components of EO was shown by the application of two equations obtained from the literature. Their larvicidal performances were correlated, for the first time, with their detailed chemical composition. Data analysis strongly indicated the toxicity of the other EO sulfur ingredients.

Essential oil of trees of the genus Ocotea (Lauraceae) in Costa Rica. I. Ocotea brenesii

Se determinó la composición química de los aceites esenciales obtenidos de las hojas y de la madera del árbol Ocotea brenesii Standl., perteneciente a la familia Lauraceae, que crece en forma silvestre en Costa Rica. Para el estudio se utilizaron técnicas de cromatografía de gases capilar con detector de ionización de flama (GC/FID) y cromatografía de gases capilar acoplada a un detector de espectrometra de masas (GC/MS). Del aceite volátil de las hojas fueron identificados 64 constituyentes, que correspondieron a un 85.9% del aceite. Del aceite de la madera se identificaron 57 compuestos que correspondieron a un 69.0% del aceite. Los constituyentes mayoritarios que se identificaron en el aceite de las hojas fueron alfa-copaeno (21.1%), gamma-cadineno (9.2%), espatulenol (7.3%), globulol (5.6%) y beta-cariofileno (5.2%). Los constituyentes mayoritarios del aceite de la madera fueron alfa-copaeno (6.6%), óxido de cariofileno (6.3%), beta-cariofileno (6.1%) y el epóxido del humuleno (4.6%). La composición de los aceites es de naturaleza terpénica y no presentaron compuestos del tipo fenilpropanoide o bencenoide que son constituyentes característicos de la mayoría de los aceites de plantas del género Ocotea investigados anteriormente

The chemical composition of the essential oils from leaves and wood of Ocotea brenesii Standl. growing wild in Costa Rica was determined by capillary GC/FID and GC/MS. From the leaves, 4 compounds were identified, corresponding to 85.9% of the oil, and from the wood 57 compounds were identified corresponding to 69.0% of the oil. The major constituents identified in the leaf oil were alpha-copaene (21.1%), gamma-cadinene (9.2%), spathulenol (7.3%), globulol (5.6%) and beta-caryophyllene (5.2%). The major constituents of the wood oil were alpha-copaene (6.6%), caryophyllene oxide (6.3%), beta-caryophyllene (6.1%) and humulene epoxide (4.6%)

A novel formulation design about water-insoluble oily drug: preparation of zedoary turmeric oil microspheres with self-emulsifying ability and evaluation in rabbits.

To enhance in vivo absorption of zedoary turmeric oil (ZTO) and develop new formulations of a water-insoluble oily drug, novel ZTO microspheres with self-emulsifying ability, called self-emulsifying microspheres here, were prepared in a liquid system by the quasi-emulsion solvent diffusion method. The microspheres containing hydroxypropyl methylcellulose acetate succinate (HPMCAS-LG), Talc and Aerosil 200 formed the stable surfactant-free emulsion when exposed to the pH 6.8 phosphate buffer, and were significantly different from the conventional self-emulsifying systems (SES), defined as isotropic mixtures of oil, surfactant and drug. Micromeritic properties, the efficiency of emulsification and the drug-release rate of the resultant microspheres were investigated. The bioavailability of the microspheres to the conventional self-emulsifying formulation for oral administration was evaluated in 12 healthy rabbits. A HPLC method was employed to determine the plasma concentration of Germacrone, an indexical component found in ZTO. The release rates of ZTO and Germacrone from the microspheres were enhanced significantly with increasing amounts of dispersing agents, and the efficiency of self-emulsification greatly depended on the HPMCAS-LG/Aerosil 200 ratio. The emulsion droplets released from the microspheres were much smaller than that of the conventional SES. The microsphere bioavailability (F) to the conventional SES for oral administration was 157.7%. Our method greatly improved the bioavailability of the water-insoluble oily drug from the self-emulsifying microspheres over the conventional SES and it is useful for the oily drug to form solid preparations.