Essential oils from Ocimum basilicum cultivars: analysis of their composition and determination of the effect of the major compounds on Haemonchus contortus eggs.

The continuous use of synthetic anthelmintics against gastrointestinal nematodes (GINs) has resulted in the increased resistance, which is why alternative methods are being sought, such as the use of natural products. Plant essential oils (EOs) have been considered as potential products for the control of GINs. However, the chemical composition and, consequently, the biological activity of EOs vary in different plant cultivars. The aim of this study was to evaluate the anthelmintic activity of EOs from cultivars of Ocimum basilicum L. and that of their major constituents against Haemonchus contortus. The EOs from 16 cultivars as well the pure compound linalool, methyl chavicol, citral and eugenol were used in the assessment of the inhibition of H. contortus egg hatch. In addition, the composition of three cultivars was simulated using a combination of the two major compounds from each. The EOs from different cultivars showed mean Inhibition Concentration (IC50) varying from 0.56 to 2.22 mg/mL. The cultivar with the highest egg-hatch inhibition, Napoletano, is constituted mainly of linalool and methyl chavicol. Among the individual compounds tested, citral was the most effective (IC50 0.30 mg/mL). The best combination of compounds was obtained with 11% eugenol plus 64% linalool (IC50 0.44 mg/mL), simulating the Italian Large Leaf (Richters) cultivar. We conclude that different cultivars of O. basilicum show different anthelmintic potential, with cultivars containing linalool and methyl chavicol being the most promising; and that citral or methyl chavicol isolated should also be considered for the development of new anthelmintic formulations.

Acute Toxicity and Sub-lethal Effects of the Essential Oil of Aristolochia trilobata and Its Major Constituents on Nasutitermes corniger (Termitidae: Nasutitermitinae).

Nasutitermes corniger (Motschulsky, 1855) (Termitidae: Nasutitermitinae) is an important pest in urban environments and bioinsecticides can be an alternative to its control. Here, we determined the toxicity and repellence of the essential oil (EO) prepared from stems of Aristolochia trilobata L. (Aristolochiaceae) and its major constituents on N. corniger. We also investigated behavioral changes of individuals exposed to limonene. The lethal dose required to kill 50% of N. corniger population (LD50) of EO of A. trilobata was 2.44 µg mg-1. Limonene was the most toxic compound to N. corniger followed by linalool (LD50 = 1.02 and 1.29 µg mg-1, respectively). In addition, all treatments presented median lethal time (LT50) less than 11 h. A. trilobata EO and its constituents showed irritability activity, but only limonene repelled soldiers more than workers. The negative behaviors of N. corniger groups were higher in individuals treated with limonene. A. trilobata EO and its constituents, especially the limonene, are promising for the control of N. corniger due the high toxicity, repellence, and possible disturbance in the colonies.

Lethal Effect and Behavioral Responses of Leaf-Cutting Ants to Essential Oil of Pogostemon cablin (Lamiaceae) and Its Nanoformulation.

Leaf-cutting ants belonging to the genus Atta (Formicidae: Myrmicinae) are important pests in agricultural and forest environments. In the present study, we evaluated the formicidal activity of the essential oil of Pogostemon cablin and its nanoformulation on the leaf-cutting ants: Atta opaciceps (Borgmeier, 1939), Atta sexdens (Linnaeus, 1758), and Atta sexdens rubropilosa Forel, 1908. The nanoformulation was developed by magnetic stirring using polyoxyethylene (36%), pure ethanol (36%), essential oil of P. cablin (18%), and water (10%). Bioassays of acute toxicity by fumigation and behavioral bioassays in treated arenas, with and without choice, were performed. The essential oil of P. cablin and its nanoformulation demonstrated efficient insecticidal activity and irritability to ant species. The concentration required to kill 50% of workers varied from 1.06 to 2.10 µL L-1, with a mean time to death of less than or equal to 42 h. The essential oil of P. cablin and its nanoformulation reduced the displacement and velocity speed of the workers of A. opaciceps and A. sexdens rubropilosa in totally treated arenas. In the bioassays with choices, the three species of ants walked less and at a greater speed on the treated side of arena. This work demonstrates the potential of the essential oil of P. cablin and its nanoformulation to the generation of new formicidal products.

Analysis of genetic diversity of Hyptis pectinata (L.) Poit. plants using ISSR markers.

Hyptis pectinata, popularly known as 'sambacaitá' or 'canudinho', is a medicinal and aromatic species widely used in the Brazilian Northeast. In Sergipe, the excessive extraction of natural resources may reduce the genetic variability of native plants. Thus, molecular markers have frequently been applied to the characterization of genetic diversity as the basis for germplasm conservation and breeding programs. The objective of the present study was to evaluate the genetic diversity of H. pectinata plants collected in different municipalities of the State of Sergipe using ISSR molecular markers. Thirty-four primers were tested, nine of which were selected for providing reproducible and analyzable amplification products, resulting in 67 polymorphic bands. The expected heterozygosity ranged from 0.32 to 0.45, with a mean of 0.39. Polymorphism information content was of 0.49, which classifies the markers as moderately informative. A dendrogram was constructed using unweighted pair group method with arithmetic mean, forming three clusters: Cluster I (79 plants); Cluster II (4 plants); and Cluster III (2 plants). Jaccard's similarity coefficients ranged from 0.06 to 0.98. The plants SAM-117 and SAM-119 presented greater similarity. Conversely, SAM-107 and SAM-171 were the most genetically distant. In general, H. pectinata plants collected in the State of Sergipe presented low to moderate genetic diversity.

Assessment of genetic diversity of a native population of Eplingiella fruticosa: a plant with therapeutic potential.

Eplingiella fruticosa (Salzm. ex Benth.) Harley & J.F.B. Pastore, ex Hyptis fruticosa Salzm. ex Benth. is an aromatic and medicinal plant of the family Lamiaceae, found mainly in regions with intense anthropic activity. Information on the genetic diversity of this species is scarce. However, it can be assessed using molecular markers that identify the level of diversity among phenotypically identical individuals. The present study aimed to characterize the genetic diversity of a native population of E. fruticosa from the State of Sergipe using ISSR molecular markers. Samples of 100 plants were collected in 11 municipalities of the State of Sergipe and analyzed using eight ISSR primers, resulting in 72 informative bands. The cluster analysis obtained using the neighbor joining method resulted in three groups: Group I consisted of 50 plants, mainly from the municipalities of Areia Branca, Estância, Japaratuba, Moita Bonita, Pirambu, and Salgado; Group II was formed by 21 plants, with nine representatives from the municipality of Itaporanga d'Ajuda and 13 representatives from other municipalities; Group III was composed by 29 plants, being represented mainly by the municipalities of Malhada dos Bois and São Cristóvão. The smallest genetic distance occurred between plants EPF94 and EPF96 (0.250), and the greatest distance occurred between plants EPF50 and EPF96 (0.9778). The Shannon index had a mean value of 0.42, and diversity was considered moderate. Heterozygosity had a mean value of 0.267 and was considered low. Polymorphic information content (0.253) was considered moderately informative. Genetic diversity of E. fruticosa plants was intermediate, and the results of the present study can assist in the conservation and use of the genetic resources of this species.

Genetic diversity of native populations of Croton tetradenius Baill. using ISSR markers.

Brazil has about 300 Croton species in different types of vegetation. Croton tetradenius Baill., which is endemic to the Northeast region and predominant in the Caatinga vegetation, stands out among the several species of this genus. Considering the importance of knowing the genetic variability of a species, the objective of this study was to analyze the genetic diversity of the genotypes of natural populations of C. tetradenius in the State of Sergipe, using ISSR molecular markers. Forty individuals were sampled in four natural populations of the State of Sergipe, Brazil. Thirteen primers were used for DNA amplification using ISSR-PCR, totaling 77 amplified fragments, of which 94.8% were polymorphic. Results of the cluster analysis obtained by the Jaccard's similarity index, using the UPGMA method, resulted in the formation of six distinct clusters. Analysis of molecular variance (AMOVA), used to estimate the genetic variability among populations, revealed significant genetic variance (P < 0.01) between and within the studied populations, and most of the genetic diversity was found (87%) within populations. According to the Jaccard's similarity index, none of the studied plants was genetically identical. CTE210 and CTE305 presented high similarity index (0.76), while CTE105 presented low similarity index (<0.16) with all related individuals. ISSR markers were efficient and allowed the formation of a molecular profile, and had sufficient polymorphism to estimate the genetic variability between the accessions of the studied populations.

Genetic variability in Jatropha curcas L. from diallel crossing.

Physic nut (Jatropha curcas L.) presents high oilseed yield and low production cost. However, technical-scientific knowledge on this crop is still limited. This study aimed to evaluate and estimate the genetic variability of hybrids obtained from dialell crossing. Genetic variability was carried out using ISSR molecular markers. For genetic variability, nine primers were used, and six were selected with 80.7% polymorphism. Genetic similarity was obtained using the NTSYS pc. 2.1 software, and cluster analysis was obtained by the UPGMA method. Mean genetic similarity was 58.4% among hybrids; the most divergent pair was H1 and H10 and the most similar pair was H9 and H10. ISSR PCR markers provided a quick and highly informative system for DNA fingerprinting, and also allowed establishing genetic relationships of Jatropha hybrids.

Analysis of genetic diversity of a native population of Myrcia lundiana Kiaersk. plants using ISSR markers.

Myrcia lundiana Kiaersk. is a tree of the family Myrtaceae found in tropical and subtropical areas of the southern hemisphere that produces essential oil. The aim of this study was to characterize the genetic diversity of M. lundiana plants from a native population of Parque Nacional de Itabaiana, using inter-simple sequence repeat molecular markers. Thirty-five primers were tested, 20 of which were polymorphic, resulting in 135 polymorphic and informative bands. Results of the cluster analysis, obtained using the unweighted pair group method with arithmetic mean, grouped plants into three clusters: Cluster I - MLU001, MLU002, MLU003, MLU004, MLU005, MLU006, MLU018, MLU019, MLU020, MLU021, MLU022; MLU008, MLU011, MLU012, MLU014, MLU015, MLU017, MLU026, and MLU028; Cluster II - MLU007, MLU009, MLU010, MLU013, and MLU016; and Cluster III - MLU023, MLU024, MLU025, and MLU027. Jaccard similarity coefficients for pair-wise comparisons of plants ranged between 0.15 and 0.87. MLU014 and MLU015 presented low genetic diversity, with a similarity index of 0.87. Conversely, MLU007 and MLU019 presented high diversity, with a similarity index of 0.15. According to the structure analysis, three distinct clusters were formed. Genetic diversity of M. lundiana plants was intermediate, and expansion of its genetic diversity is necessary. MLU026 and MLU028 are the most suitable for selection in breeding programs, since they clearly represent all of the diversity present in these plants. Moreover, these results provide important information on the existing genetic variability, highlighting the importance of Parque Nacional de Itabaiana for the conservation of this species.

Genetic diversity analysis of Varronia curassavica Jacq. accessions using ISSR markers.

Varronia curassavica Jacq. is a medicinal and aromatic plant from Brazil with significant economic importance. Studies on genetic diversity in active germplasm banks (AGB) are essential for conservation and breeding programs. The aim of this study was to analyze the genetic diversity of V. curassavica accessions of the AGB of Medicinal and Aromatic Plants of the Federal University of Sergipe (UFS), using inter-simple sequence repeat molecular markers. Twenty-four primers were tested, and 14 were polymorphic and informative, resulting in 149 bands with 97.98% polymorphism. The UPGMA dendrogram divided the accessions into Clusters I and II. Jaccard similarity coefficients for pair-wise comparisons of accessions ranged between 0.24 and 0.78. The pairs of accessions VCUR-001/VCUR-503, VCUR-001/VCUR-504, and VCUR-104/VCUR-501 showed relatively low similarity (0.24), and the pair of accessions VCUR-402/VCUR- 403 showed medium similarity (0.78). Twenty-eight accessions were divided into three distinct clusters, according to the STRUCTURE analysis. The genetic diversity of V. curassavica in the AGB of UFS is low to medium, and it requires expansion. Accession VCUR-802 is the most suitable for selection in breeding program of this species, since it clearly represents all of the diversity present in the AGB.

Genetic diversity of Lippia sidoides Cham. and L. gracilis Schauer germplasm.

The conservation of plants in germplasm banks ensures the characterization and availability of these resources for future generations. The present study used DNA markers to obtain genetic information about germplasm collections of Lippia sidoides and L. gracilis, which are maintained in an Active Germplasm Bank (AGB). Genetic variability of samples in the AGB was assessed using 12 combinations of amplified fragment length polymorphism (AFLP) primers (EcoRI/MseI). Twenty simple sequence repeat primers designed for L. alba were tested to determine their transferability in L. sidoides and L. gracilis. The AFLP markers generated 789 markers. The assessed loci exhibited a moderate Shannon diversity index (I = 0.42) in both species, suggesting that the conserved accessions possess an intermediate level of genetic diversity. Twelve microsatellite loci amplified satisfactorily, and nine loci were polymorphic in each species. A total of 23, 22, and 36 alleles, with an average of 2.5, 2.4, and 3.27 alleles per locus were identified for L. sidoides and L. gracilis accessions in the AGB, and Lippia sp sampled plants, respectively. Analyses of genetic structure permitted the identification of three different groups using both sets of markers, of which two were representative of L. sidoides. The information generated in this study may help to create, expand, and maintain collections of these species and may assist in genetic-breeding programs.

Analysis of genetic diversity of Laeliinae (Orchidaceae) in the State of Sergipe using ISSR markers.

The Orchidaceae represent one of the largest and most diverse families on the planet. However, this family is constantly threatened by predators and by the advancement of urban centers over its natural habitats. The objective of this study was to use inter-simple sequence repeat markers to evaluate the genetic diversity between orchid accessions of the Laeliinae subtribe, which comprise part of the Orchidaceae study collection at the Department of Agronomic Engineering of the Federal University of Sergipe. DNA was extracted from each specimen by using an adapted 2% cetyltrimethyl ammonium bromide protocol. Similarity between individuals was calculated using the Jaccard method. Clustering was carried out by the unweighted pair group method with arithmetic mean method, with resampling and 10,000 bootstraps. Eighty-seven fragments were obtained, all of which were polymorphic, revealing high variability between accessions. The mean similarity was 35.77% between Encyclia sp individuals, and 35.90% between specimens of Cattleya tigrina. For Epidendrum secundum, a relationship between geographic and genetic distances was observed, and the accession collected in the southern part of the State of Sergipe (Serra de Itabaiana National Park) was more divergent than that of the other parts of the state. The data generated in this study will guide further research aimed at the ex situ conservation of these materials.

Molecular characterization of patchouli (Pogostemon spp) germplasm.

Patchouli [Pogostemon cablin (Blanco) Benth.] is an aromatic, herbaceous plant belonging to the Lamiaceae family native to Southeast Asia. Its leaves produce an essential oil regularly used by the perfume and cosmetics industries. However, since patchouli from the Philippines and India were described and named Pogostemon patchouli, there has been a divergence in the identity of these species. The objective of the current study was to study the genetic diversity of patchouli accessions in the Active Germplasm Bank of Universidade Federal de Sergipe using microsatellite and inter simple sequence repeat markers. The results of both types of molecular markers showed that there are two well-defined clusters of accessions that harbor exclusive alleles. It was observed that these two clusters are genetically distant, suggesting that they belong to two different species. Based on the results, two accessions were classified as Pogostemon heyneanus and the remaining accessions were classified as P. cablin.

Assessment of the repellent effect of Lippia alba essential oil and major monoterpenes on the cattle tick Rhipicephalus microplus.

The control of Rhipicephalus microplus (Ixodida: Ixodidae) is achieved using synthetic acaricides. However, resistant tick populations are widespread around the world. Plant essential oils can act as repellents, keeping ticks away from hosts and decreasing the selection pressure on synthetic acaricides. The aim of this study was to evaluate the in vitro repellent effect of Lippia alba essential oil on R. microplus larvae. Leaves from two L. alba genotypes maintained under the same agronomic and environmental conditions were collected. Essential oil was extracted by hydrodistillation and analysed by gas chromatography-mass spectrometry (GC-MS). The major monoterpenes detected in the chemical analysis were commercially acquired and tested. For the repellency test, a glass rod was vertically fixed to measure active climbing of approximately 30 R. microplus larvae aged 14-21 days in response to essential oils and monoterpenes. Repellency was evaluated at 1 h, 3 h and 5 h after treatment. Variation in repellent action was detected between the genotypes. The major monoterpenes identified in the essential oils (limonene and carvone) showed low repellent effects in comparison with intact essential oils. Thus, the present results showed that L. alba essential oil contains bioactive compounds with great repellent activity against ticks that varies according to the plant genotype.

Influence of storage time and temperature on the chemical composition of the essential oil of Hyptis pectinata L. Poit / Influência do tempo de armazenamento e da temperatura na composição química do óleo essencial de Hyptis pectinata L. Poit

ABSTRACT Hyptis pectinata, popularly known as “sambacaitá”, is a native medicinal herb used by local people for treating disease. Its pharmacological, antimicrobial, and medicinal properties have been reported in several studies. The essential oil of the leaves is rich in terpene compounds responsible for its properties. Because there are factors that can influence the chemical composition of essential oils, the objective of this study was to evaluate the influence of storage on Hyptis pectinata essential oil for 360 days at two different temperatures. The essential oil was distilled from dried leaves of seven-month-old plants using the hydrodistillation method, and the chemical composition was determined using GC-MS and GC/FID. The effects of storage on the essential oil Hyptis pectinata were tested over the course of a year (0, 15, 30, 60, 90, 120, 150, 180, 240, 300, and 360 days), using two temperatures: room (±32ºC) and freezer (-20ºC). The predominant compounds in the essential oil are β–caryophyllene, caryophyllene oxide, and germancrene D. The concentration of the chemical constituents of the essential oil varied depending on the storage temperature, and over the 360 days. The storage of the essential oil at room temperature over one year resulted in higher concentrations of β-elemene, α-copaene, germacrene D, caryophyllene oxide, and (E,E)-α-farnesene and lower content of α-humulene and β-caryophyllene, compared to the results obtained from storing the essential oil in a freezer. These results indicate that the essential oil should be stored in a freezer, which provides greater stability to the concentration of the chemical constituents.

RESUMO Hyptis pectinata, conhecida popularmente como Sambacaitá é uma erva medicinal nativa utilizada pela população local para o tratamento de enfermidades, cujas propriedades farmacológicas, antimicrobianas e medicinais foram relatadas em diversos estudos. O óleo essencial das folhas é rico em compostos terpênicos responsáveis pelas suas propriedades. Devido à existência de fatores que podem influenciar a composição química dos óleos essenciais, o objetivo deste trabalho foi avaliar a influência do armazenamento do óleo essencial Hyptis pectinata durante 360 dias em duas temperaturas diferentes. O óleo essencial foi destilado a partir de folhas secas de plantas de sete meses de idade, utilizando o método de hidrodestilação e a composição química foi determinada usando CG-EM e CG-DIC. Os efeitos do armazenamento no óleo essencial Hyptis pectinata foram testados ao longo de um ano (0, 15, 30, 60, 90, 120, 150, 180, 240, 300 e 360 dias), utilizando duas temperaturas: ambiente (±32ºC) e freezer (-20ºC). Os compostos predominantes no óleo essencial foram o β-cariofileno, óxido de cariofileno e germancreno D e houve variação na concentração dos constituintes químicos do óleo essencial, dependendo da temperatura de armazenamento, bem como ao longo dos 360 dias. O armazenamento do óleo essencial, à temperatura ambiente ao longo de um ano resultou em maiores concentrações de β-elemeno, α-copaeno, germacreno D, óxido de cariofileno e (E, E) -α-farneseno e menores teores de α-humuleno e β-cariofileno, quando comparado com os resultados obtidos a partir de armazenamento do óleo essencial no freezer. Estes resultados indicam que o óleo essencial deve ser estocado no freezer, o que propicia maior estabilidade na concentração dos constituintes químicos.

Molecular and chemical characterization of vetiver, Chrysopogon zizanioides (L.) Roberty, germplasm.

Due to the economic interests in vetiver, Chrysopogon zizanioides (L.) Roberty, molecular and chemical studies are essential to generate information for its sustainable exploitation. The aim of this study was to undertake a molecular and chemical characterization of vetiver accessions of the active germplasm bank of the Universidade Federal de Sergipe. The molecular characteristics of the accessions were studied using amplified fragment length polymorphism markers, with a total of 14 primer combinations that generated 442 loci, allowing us to observe that these accessions have similar genomes. The vetiver accessions were divided into three distinct groups, where accession UFS-VET005 was the most differentiated and accession UFS-VET004 had the lowest essential oil content (0.70%). The content of the chemical constituents of the essential oils was observed to vary, with a predominance of khusimol, which ranged from 18.97 to 25.02%. It was possible to divide the vetiver accessions into two groups based on chemical composition, and these groups do not correlate with the molecular grouping. Therefore, it is necessary to perform molecular and chemical analyses to characterize vetiver accessions.

Development of a novel set of microsatellite markers for Lippia alba (Verbenaceae).

Microsatellite primers were developed and optimized for Lippia alba to characterize the L. alba germplasm bank of Universidade de São Paulo. A genomic library enabled the design of 9 microsatellite primers. Six of the 9 primers yielded polymorphic products, which defined 2 groups in the bank. The data provide support to characterize germplasm banks, genetic breeding programs for L. alba, and other genetic diversity studies and classifications of species in the genus Lippia.

Cross-species transferability of microsatellite markers in the genus Lippia.

The cross-species transferability of 20 microsatellite markers was tested in the genus Lippia. Eleven markers were polymorphic after screening 19 accessions of Lippia sidoides and Lippia gracilis maintained in the Active Germplasm Bank (AGB) from Universidade Federal de Sergipe. Additionally, 40 accessions of Lippia spp were collected in Sergipe to increase the germplasm bank. A total of 23, 22, and 36 alleles were identified, with an average of 2.3, 2.2, and 3.27 alleles per locus, respectively, for each group. The markers that were used were efficient tools to access genetic diversity in the germplasm bank and will be useful for further research aiming at the conservation and management of these important aromatic species.

Molecular characterization of bromeliads from northeast Brazil.

Bromeliaceae is an important botany family that includes many species with economic value; demand for members of this family is increasing. However, illegal collection frequently occurs, drastically reducing the species populations; thus, it is necessary to collect and store Bromeliaceae genetic material. In this study, we identified and quantified genetic variability of the Bromeliad family using dominant markers to create the first Germplasm Bank in the northeast region of Brazil. Molecular tools were used to characterize the collected accessions. The combination of 11 inter-simple sequence repeats and 13 random amplified polymorphic DNA markers were used to detect the genetic variability of wild bromeliad accessions.

Development and characterization of novel microsatellite markers in Hyptis pectinata (Lamiaceae).

A microsatellite-enriched library was constructed and a set of 19 SSR markers were developed to characterize a germplasm collection of Hyptis pectinata (L.) Poit., maintained at the Universidade Federal de Sergipe (UFS). Fifteen markers of 19 ranged from moderately to highly polymorphic. A total of 113 alleles were identified, with a mean of 7.52 alleles per locus. The mean HO and HE were 0.582 and 0.657, respectively. The primers developed were efficient tools for accessing the genetic diversity of the germplasm collection analyzed and may also be useful for other studies involving this species and other species in the genus Hyptis.

Cytotoxic effects of essential oils from three Lippia gracilis Schauer genotypes on HeLa, B16, and MCF-7 cells and normal human fibroblasts.

This study aimed to evaluate the chemical composition of the essential oils from three genotypes of Lippia gracilis Schauer (Verbenaceae) and investigate the cytotoxic activities of these oils. Essential oils were extracted from the leaves using a Clevenger-type apparatus, and chemical analysis was performed using a gas chromatograph coupled to a mass spectrometer and flame ionization detector. 3T3, MRC5, B16, HeLa, and MCF-7 cell lines were used to study the in vitro cytotoxicity of the essential oils, and the level of cell death was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test with three replicates. The cytotoxic activity was expressed as the concentration that inhibited 50% of cell growth. The main compound in the essential oil of LGRA-106 was thymol (40.52%), while LGRA-109 and LGRA-201 contained 45.84 and 32.60% carvacrol, respectively, as their major compound. The essential oils of L. gracilis showed cytotoxic activity against both normal and tumor cells at concentrations below 100 µg/mL; this demonstrated the antitumor potential of these essential oils, which should be further investigated.