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The objective of this study was to optimize the enzymatic pretreatment process of extracting menthol, a major component of the essential oil stored in the trichomes of fresh leaves of Mentha arvens...

The quality and content of essential oils extracted from medicinal plants can be affected by storage conditions. The present work evaluated the influence of different storage conditions of Ocimum gratissimum leaves on essential oils. The study was conducted in two environments (controlled and natural), in two types of packaging (plastic and paper) during five storage times (0, 3, 6, 9, and 12 months). Also evaluated was the damage caused to the glandular trichomes and the fungal contamination of the stored leaves. For this data set, the study was done using multivariate exploratory analysis PCA, HCA and K-means. Among the environments, the use of paper storage in a natural environment presented a reduction of up to 74.3% in essential oil content and greater damage to the trichomes. The plastic packaging prevented the proliferation of fungi. The best storage condition proved to be a controlled environment from 6 months to 9 months in plastic packaging.

EnglishMedicinal plants are generally commercialized dried. However, temperatures used in their drying processes may interfere with the content and chemical composition of their essential oils. The Lippia origanoides possesses thymol in the essential oil that is stored in glandular trichomes. Thymol is a major component of economic importance in the chemical and pharmaceutical industry. The objective of this study was to evaluate the effect of the drying temperatures of L. origanoides leaves regarding trichome integrity, content, and chemical composition of the essential oil. The experimental design was completely randomized with four treatments defined by oven drying temperatures (40, 50, 60, and 70oC) and four replications. Essential oil was extracted by hydro distillation and the essential oil contents were determined (%). Chemical composition of the oil was analyzed by gas chromatography coupled to mass spectrometry. Scanning electron microscopy was carried out to determine trichome integrity. Drying the L. origanoides leaves in a forced ventilation oven at 40°C minimized the loss of extracted essential oil content (17.5g kg-1) and relative thymol percentage. Leaves dried at the temperatures of 60 and 70oC exhibited a higher percentage of ruptured trichomes and reduced essential oil content to 13.7g kg-1 and 11.8g kg-1, respectively. Key words: Lippia origanoides; medicinal plant; secretory structures; drying; thymol portuguesAs plantas medicinais sao geralmente comercializadas secas, no entanto, as temperaturas utilizadas nos processos de secagem podem interferir no teor e composicao quimica dos oleos essenciais destas plantas. A Lippia origanoides possui timol em seu oleo essencial, que se encontra armazenado em tricomas glandulares. O timol e um componente majoritario de importância economica na industria quimica e farmaceutica. O objetivo do trabalho foi estudar o efeito das temperaturas de secagem de folhas de L. origanoides na integridade dos tricomas, teor e composicao quimica do oleo essencial. O delineamento experimental foi inteiramente casualizado, com quatro tratamentos definidos por temperaturas de secagem em estufa (40oC, 50oC, 60oC e 70oC) e quatro repeticoes. Foram realizadas extracoes por hidrodestilacao e determinacao dos teores dos oleos essenciais (%), analise de composicao quimica do oleo por cromatografia gasosa acoplada a espectrometria de massas e microscopia eletronica de varredura para determinacao da integridade dos tricomas. A secagem das folhas de L. origanoides em estufa de ventilacao forcada a 40oC minimizou a perda do teor de oleo essencial extraido (17,5g kg-1) e porcentagem relativa de timol. Folhas secas em temperatura de 60 e 70oC exibiram maior porcentagem de tricomas rompidos e reducao do teor de oleo essencial para 13,7g kg-1 e 11,8g kg-1, respectivamente. Palavras-chave: Lippia origanoides; planta medicinal; estruturas secretoras; secagem; timol

This study aimed to evaluate the effects of dietary Brazilian red pepper ( Schinus terebinthifolius Raddi) essential oil and an antimicrobial agent on weanling pig growth performance, diarrhea occurrence, pH of the digestive content, small intestine histology, and intestine microbial counts. Ninety weanling castrated male pigs (5.6±0.78 kg BW and 21-d old) were used in a randomized complete block design experiment with five treatments, six replications per treatment, and three animals per experimental unit (pen). The treatments were a basal diet supplemented with 0 (negative control), 500, 1000, and 1500 mg/kg Brazilian red pepper essential oil vs with 120 mg/kg chlorohydroxyquinoline (antibiotic treatment). At the end of the experimental period one animal from each pen was slaughtered to record the pH of digestive contents, small intestine histology, and intestine microbial counts. Treatments had no effect ( P> 0.05) on growth performance, diarrhea occurrence, pH of the digestive content, villus height, crypt depth, and intestinal microbial counts of weanling pigs. However, pigs fed the diet containing 500 mg/kg essential oil had greater villi density ( P 0.05) than those fed diets containing the antibiotic or 1000 and 1500 mg/kg essential oil. Thus, both Brazilian red pepper essential oil and the antibiotic are of limited benefit for enhancing the growth of weanling pigs. However, the effectiveness of growth enhancer additives may be reduced in low challenging situations as demonstrated by the current study.

One feature of the Protium genus is the presence of secretory ducts associated with the phloem. These ducts are characterized by the production of essential oils with different classes of secondary metabolites. In light of this observation, the purpose of this study was to determine which secondary metabolites are present in the secretory ducts of P. aracouchini, P. heptaphyllum, P. icicariba and P. warmingianum using histochemical tests and essential oil chemical analysis. The essential oils are present at different levels and compositions in the four studied species; other metabolites also varied from species to species. Variation was observed among the essential oil classes with oxygenated sesquiterpenes being the most representative class found in the species studied. The major component of all species was caryophyllene oxide; thus, it may be regarded as a genus characteristic. Through the results obtained, characteristics common to all species were defined, enabling the segregation of the spe...

Contamination of medicinal plants with heavy metals as Pb and Cd can affect the growth and the essential oil production of the plants and represent a risk to those who consume as medicine. This study aimed to evaluate the effects of absorption and localization of Pb and Cd on growth, ultrastructural aspects of leaves and essential oil yield and composition of Mentha arvensis, applied on the soil with increasing concentrations (8, 16, 32, 64 and 128mg kg-1). There was a differential absorption of Pb and Cd by M. arvensis mainly concentrated in the roots. Pb was found in small amounts in the leaves while Cd largely exceeded the safety limit without symptoms of toxicity. The ultrastructural analysis revealed the metal accumulation on vesicles surrounding the mitochondria and the presence of electron dense deposits surrounding the mitochondria, nucleus and chloroplasts. Little changes caused by Pb and Cd application were not enough to affect the growth and essential oil yield and composition of M. arvensis

The aim of the study was to evaluate the effect of the arbuscular mycorrhizal fungi (AMF), Acaulospora morrowiae, Rhizophagus clarus and Scutellospora calospora on the growth and essential oil production of Mentha × piperita L. var. citrata plants. The experiment was conducted in a greenhouse with a 5 × 2 factorial design with five mycorrhizal treatments (uninoculated control, Acaulospora morrowiae, Rhizophagus clarus and Scutellospora calospora, and mixture of inocula) and two P levels (60 and 120 mg P dm-3 soil) with six replicates. Plants were harvested after 75 days of growth for evaluation of dry biomass, mycorrhizal colonization of roots, number of spores in soil, nutrient content of leaves, and composition, content and yield of essential oil. The mycorrhizal treatments influenced all the characteristics evaluated, except the number of spores in soil. AMF colonization was most evident at the lowest dose of phosphate fertilizer applied, except for R. clarus, and in all treatments mycorrhizal colonization was above 45%. Colonization also influenced the nutrient content of the leaves of M. piperita var citrata and increased leaf dry biomass. The content and yield of essential oils were higher in plants colonized by AMF fungi with the 60 mg P fertilization dose, except those colonized by R. clarus which had higher essential oil production only with the 120 mg dm-3 P treatment. The two major components in the essential oils for the plants in all the treatments were linalool and linalyl acetate. Key words: Acaulospora, Rhizophagus, Scutellospora, linalool, linalyl acetate, phosphorus fertilization.

Alpinia zerumbet is a medicinal plant from Asian origin used in folk medicine for the treatment of hypertension, which effect is attributed to terpinen-4-ol, the major component of the essential oil. The objective of this work was to identify the essential oil secretory structures in the leaf, flower, root and rhizome of this plant, and analyze the content and the chemical composition of the oil in the different organs of the plant. Sections were subjected to histochemical test with Nadi reagent for in situ localization of secretion. The essential oil extraction was performed by hydrodistillation in a Clevenger apparatus and the compounds were identified in CG-EM/FID. The histochemical test was positive for terpenoids, confirming the presence of essential oil stored in secretory structures named oils cells present in all analyzed organs. The higher essential oil content was found on the leaf (0.30%), while the petal and the rhizome presented content of 0.10% and 0.06%, respectively. It was not possible to determine essential oil content of the root due to the low amount of biomass produced. There were qualitative and quantitative differences in the chemical composition of the essential oil in the different plant organs, but the major constituent in all of them was the terpinen-4-ol, followed by 1,8 cineol in the leaf and by the α-terpineol in the flower and rhizome.

Light conditions can promote the growth and development of plants and contribute to increase the essential oil production of commercially cultivated medicinal and aromatic species. In view of the great importance of Ocimum gratissimum L., Lamiaceae, as an aromatic plant, the objective of this work was to determine the effect of light intensities (approximately 4, 7, 11 and 20 mol m−2 d−1) on growth, foliar micromorphology, essential oil content, yield and chemical composition of O. gratissimum. Biomass production of different organs, root:shoot ratio and leaf mass per area were found to linearly increase with increased light availability, whereas stem dry matter fraction, number of leaves, leaf area and plant height have increased up to 10 mol m−2 d−1 and decreased from this value. The tector trichomes density increased with increased light availability, but there was no effect of light treatments on the glandular trichomes density and essential oil content. Regardless of the light level, the major component of the essential oil was eugenol. The essential oil yield per plant increased linearly with light intensity as a direct effect of increased leaf biomass under similar conditions. Keywords: eugenol, medicinal plant, photosynthetically active radiation

The objective of the present work was to determine the effects of colored shading on the density of glandular and tectorial trichomes, and on the yield, productivity and composition of the essential oil of Ocimum selloi Benth. Plants were cultivated for 90 days under full sunlight or under ChromatiNet 50% red or blue netting. The highest density of glandular trichomes was observed in plants that had received full sunlight. None of the light treatments altered the yield of oil, although productivity was higher in plants grown under full sunlight by virtue of the greater leaf biomass that accumulated under such conditions. The compositions of the oils varied according to the quality of light. Although the qualitative profiles of the oils of plants grown under full sunlight or red shading were similar, that obtained from plants grown under blue shading presented a larger number of constituents. The highest level of methyl chavicol (93.2%), the major component of the oil, was observed in plants grown under full sunlight.

Ocimum selloi essential oil (2, 20, and 200 mg/kg; p.o.) reduced, in a dose-dependent way, the abdominal contraction induced by acetic acid (0.6%; i.p.) and the diarrhea episodes induced by castor oil in mice. At the higher dose (200 mg/kg; p.o.), the essential oil significantly reduced intestinal transit (P

A prática da adubação orgânica, além de fornecer nutrientes para as plantas, proporciona a melhoria da estrutura física do solo, aumenta a retenção de água, diminui as perdas por erosão e favorece o controle biológico. O elixir paregórico (Ocimum selloi Benth.) é uma espécie medicinal nativa das regiões Sul e Sudeste do Brasil onde é utilizada popularmente como antidiarréico, antiespasmódico e antiinflamatório. Este trabalho teve como objetivo verificar o efeito de diferentes doses de dois adubos orgânicos no crescimento, no rendimento e na composição do óleo essencial de elixir paregórico. Os experimentos foram conduzidos em Lavras, MG, em estufa plástica com os seguintes tratamentos de adubação: ensaio A - esterco bovino: 1) sem adubação (controle); 2) solo + 3kg m-2 de esterco; 3) solo+ 6kg m-2 de esterco; 4) solo+ 9kg m-2 de esterco; 5) solo + 12kg m-2 de esterco; ensaio B - Esterco avícola: 1) sem adubação (controle); 2) solo + 1,5kg m-2 de esterco; 3) solo + 3kg m-2 de esterco; 4) solo + 4,5kg m-2 de esterco e 5) solo + 6kg m-2 de esterco. Foi verificada a influência das doses de adubação com esterco bovino e galinha sobre o crescimento da planta em altura e diâmetro do caule, acúmulo de biomassa seca, AF, AFE, RPF, teor de clorofilas, espessura do limbo foliar, rendimento e composição química do óleo essencial. The organic fertilization provides nutrients for the plants, improves the soil physical structure, increases the water retention, reduces the erosion losses and favors the biological control. Ocimum selloi is a native medicinal plant of south and southeast of Brazil where is used popularly as antidiarrhetic, antispasmodic and anti-inflammatory. This research aimed to verify the effect of different doses of two organic fertilizers souces in O. selloi growth, essential oil yield and chemical composition. The experiments were carried out in Lavras, MG, with pots in polyethylene greenhouse with two manuring treatments: Test A - Cattle manure: 1) Soil without manuring (control); 2) Soil + 3kg m-2 cattle manure; 3) Soil + 6kg m-2 cattle manure; 4) Soil + 9kg m-2 cattle manure; 5) Soil + 12kg m-2 cattle manure; Test B - Chicken manure: 1) Soil without manuring (control); 2) Soil + 1.5kg m-2 chicken manure; 3) Soil + 3 kg m-2 chicken manure; 4) Soil + 4.5kg m-2 chicken manure and 5) Soil + 6kg m-2 chicken manure. The influence of cattle and chicken manuring doses was verified on plant height, stem diameter, dry biomass weight, TLA, SLA, LWR, chlorophylls content, leaf thickness, essential oil yield and composition.

Este estudo foi conduzido com objetivo de determinar o tipo de secagem e a fragmentação das folhas de capim-limão para otimizar o rendimento extrativo do óleo essencial. Foram estabelecidos 6 tratamentos com 2 tipos de secagem (estufa de ventilação forçada a 40ºC e sala com desumidificador) e 3 tamanhos de fragmentos das folhas secas (pulverização em moinho, fragmentos com 1 e com 20 cm de comprimento), com 4 repetições. O óleo essencial foi extraído por hidrodestilação durante 2 horas. O maior rendimento de óleo essencial foi obtido com o material seco na sala com desumidificador, não havendo diferenças significativas para os tamanhos da folha. O componente mais abundante no óleo essencial foi o citral que também apresentou as maiores concentrações nas folhas secas em desumidificador.

The ef ficacy of Ocimum selloi essential oil was evaluated for controlling the growth of mycelia and spores germination Moniliophthora perniciosa. Six compounds (99.89%) of the total oil were identified by GC-MS, of which methyl chavicol, methyl eugenol, �� -caryophyllene, germacrene-D, bicyclogermacrene and spathulenol. Essential oil was tested for anti- fungal activity, which was determined by disc diffusion and minimum inhibitory concentration (MIC) determination methods. Application of the oil reduced mycelial growth in a dose dependent manner, with maximum inhibition being observed at concentration of 1,000 ppm. Such antifungal activity could be attributed to methyl chavicol since the pure compound was shown to be similarly effective against Moniliophthora perniciosa at 1,000 ppm. The oil when applied at a concentration of 1,000 ppm, reduced the spore germination of Colletotrichum gloeosporioides and M. perniciosa by 93 and 87%, respectively, but had no effect on the Alternaria alternata. It is concluded that the oil from O. selloi and its major constituent, methyl chavicol, are efficient in inhibiting M. perniciosa, but less effective against C. gloeosporioides and A. alternata. The results obtained from this work may contribute to the development of alternative anti-fungal agents to protect the cacao crop from fungal disease.

Medicinal and aromatic plants are commonly sold dried; however, it is necessary to understand the effects different drying methods have on these materials, to ensure their efficiency and quality. Ocimum gratissimum L., Lamiaceae, is an aromatic plant whose essential oil is stored in glandular trichomes. This study aimed to confirm the effects of different drying temperatures and methods of O. gratissimum leaves on trichome integrity and essential oil content. Leaves dried in a forced ventilation oven at 60oC display damaged trichomes and a reduction in the essential oil content. The different drying methods (oven, dehumidification and air drying) were not identified to elicit changes in the essential oil content or damage to trichomes. All of the drying methods showed a reduction in fungal contamination in a logarithmic cycle. Keywords: Basilicum, Eugenol, Lamiaceae, Micromorphological analysis

Lippia alba (Mill.) N.E. Br. ex Britton & P. Wilson, Verbenaceae, is widely used in traditional Brazilian medicine for the treatment of abdominal distress. The species exhibits considerable chemical and morphological diversity, and various chemotypes have been characterized. A comparative study of L. alba, has been carried out of the morphoanatomical characteristics of the leaves and the profi les of the essential oils of the morphotypes cidreira and melissa grown in the Medicinal Plant Garden of the Universidade Estadual de Santa Cruz, Ilhéus, Bahia, Brazil. The mean plant height of cidreira was 1.80 m and the stems and branches were fairly erect, while melissa plants were smaller (1.60 m) and presented prostrate stems and branches. Although the leaf of the morphotypes look were similar, the mean values of length, width and area of the leaves of cidreira (respectively, 7.42 cm, 3.32 cm and 17.31 cm2) differed signifi cantly from those of melissa (4.68 cm, 2.35 cm and 7.32 cm2). The morphotypes presented amphistomatic leaves with uniseriate epidermis on both surfaces. The mesophyll was dorsiventral, but in cidreira the palisade parenchyma was biseriate while in melissa it was uniseriate. Simple tector and capitate glandular trichomes were present on the adaxial and abaxial surfaces of the leaf blades of both morphotypes. Six distinct types of glandular trichomes could be distinguished: types I and II were present in both morphotypes, while type III was detected only in cidreira, and types IV to VI were present only in melissa. The two morphotypes also differed with respect to the composition of the essential oil, cidreira produced oil composed mainly of citral, while the oil from melissa was rich in citral, limonene and carvone. Keywords: carvone, citral essential oil composition, leaf morphology, limonene, Lippia alba

Light can act on essential oil yield directly on synthesis of secondary metabolites, or indirectly on plant growth. Varronia curassavica Jacq., Boraginaceae, is a native medicinal species from Brazil known as “erva-baleeira”, with anti-inflammatory activity related to its essential oil. Despite pharmacological evidences of this species and its economic importance for herbal medicine production, little is known about the effect of light on growth and essential oil production. This study aimed to analyze the influence of different irradiances on growth, frequency of trichomes, essential oil yield and composition of V. curassavica. The irradiance affected plant growth, but no significant alteration on leaf biomass was detected. The increase in essential oil content under higher irradiance reflected on essential oil yield, and is associated with higher frequency of glandular, globular trichomes. The essential oil composition, rich in caryophyllene derivatives was affected by irradiance, but α-humulene, the constituent of pharmaceutical interest, remained unchanged. Keywords: Cordia verbenacea, Irradiance, Medicinal plant, Caryophyllene oxide