Effectiveness of Cymbopogon citratus Oil Encapsulated in Chitosan on Colletotrichum gloeosporioides Isolated from Capsicum annuum.

One of the principal etiological agents associated with losses in horticultural crops is the fungus Colletotrichum sp. This study aimed to evaluate the in vitro effectiveness of the essential oil (EO) from Cymbopogon citratus in chitosan supports for the control of Colletotrichum gloeosporioides isolated from sweet pepper plants. METHODS: The extraction and phytochemical analysis of the EO of C. citratus were performed along with its encapsulation in chitosan-agar in order to compare it with other techniques and determine its effect on C. gloeosporioides. RESULTS: The EO from the citral chemotype (58%) encapsulated in the chitosan-agar, with an 83% encapsulation efficiency in mass percentage, resulted in the total inhibition of mycelial growth at a minimum inhibitory concentration of 1370 ppm. This concentration was effective in controlling the disease under greenhouse conditions. The effectivity of the capsules containing EO was superior to that of other controls using EO evaluated in vitro. The capsules demonstrated an effective period of 51 days, with an additional 30 days of effectiveness after a reinfection cycle, thus providing similar results to the control with Trichoderma sp. CONCLUSIONS: Chitosan capsules present a promising strategy in the use of C. citratus EO on C. gloeosporioides, and they are highly effective and stable under in vitro and field conditions.

Assessment of cytotoxic and antimicrobial activities of two components of Cymbopogon citratus essential oil.

BACKGROUND: There is a continuing search for compuounds to improve the chemical plaque inhibitory action of oral hygiene products. Although the antibacterial effects of chlorhexidine (CHX) and essential oils components, citral/myrcene, have been described, there is contradictory information regarding their cytotoxic effects in host tissues. This study aimed to evaluate the cytotoxic activity of the major components of the oil C. citratus, citral and myrcene on human periodontal ligament fibroblast (HPLF) cultures and their antimicrobial effect on different bacterial species present in supragingival biofilm. MATERIAL AND METHODS: Cytotoxicity of the compounds to HPLF was determined by MTT assay. Antimicrobial activity was tested against reference strains of Enterococcus faecalis, Streptococcus mutans and Lactobacillus rhamnosus and for S. mutans clinical strains by broth microdilution assay. One-way analysis of variance (ANOVA) with Games-Howell post-hoc multiple comparison or unpaired t tests were used for inter- and intragroup comparisons. RESULTS: Overall, all of the compounds under study showed a cytotoxic effect to HPLF which varied in a dose-dependant manner. Whilst myrcene did not show bacteriostatic activity at tested concentrations, both citral and CHX exhibited bacteriostatic/bactericidal effects to all strains at specific concentrations, being CHX most effective to inhibit bacterial growth at lower concentrations than what observed for citral. CONCLUSIONS: Based on these findings, it would possible to conclude that whereas myrcene might be ineffective to control bacterial growth, citral could have a promising antimicrobial activity against dental colonizers with low cytotoxicity, and may be useful for preventing the onset and progression of oral diseases. Key words:Antimicrobial activity, citral, cytotoxicity, chlorhexidine, myrcene.

[Effect of glyphosate on microbiota, soil quality and biofortified bean crop in Codazzi, department of Cesar, Colombia]. / Efecto del glifosato sobre la microbiota, calidad del suelo y cultivo de frijol biofortificado en el departamento del Cesar, Colombia.

Strategies aimed at achieving food safety in crops of high nutritional value should be carried out through sustainable agricultural practices aimed at soil conservation, high yield and food safety. This latter characteristic implies food production without detectable traces of agrochemicals that threaten health. The objective of this study was to assess the effect of the herbicide glyphosate on the chemical and biological fertility of the soil and to determine its residual activity on biofortified bean seeds in Codazzi, Department of Cesar, Colombia. The method included a correlational analysis of soil quality, crop yield and residuality in bean grains. The treatments included glyphosate application and synthetic and natural mulches, compared to manual control. The results showed differences in the response of chemical, microbiological and yield indicators between treatments and the initial conditions of the bean rhizosphere. The use of the herbicide glyphosate in mulch-free soil generates yield losses of 29% associated with a higher incidence of pests and fungal diseases; in all treatments, no glyphosate residuality was detected in seeds; however, residuality was detected in other molecules derived from insecticides associated with the local production system. In conclusion, in plots with high weed pressure by Cyperus rotundus, the use of mulch is recommended as an alternative to maintain bean productivity over time; by offering protection against the effect of the herbicide on both the root system of the plant and the soil microbiota of the biofortified bean crop.

Antimicrobial activity of Cymbopogon citratus (Poaceae) on Streptococcus mutans biofilm and its cytotoxic effects

Resumen La caries dental, es una patología de origen multifactorial y actualmente los productos naturales son un tratamiento alternativo eficiente. El trabajo buscó evaluar la actividad antimicrobiana del aceite esencial de tres sustancias (Cymbopogon citratus y los componentes citral y mirceno) contra Streptococcus mutans ATCC UA159, así como su citotoxicidad sobre queratinocitos y fibroblastos humanos. A través de Microscopía Electrónica de Barrido, se observó la morfología típica de S. mutans, y una formación característica de polisacáridos, con una disposición más estructurada a las 48 h. El efecto de viabilidad bacteriana contra S. mutans en biofilms se evaluó a través de la exposición a las tres sustancias mediante el uso de la técnica de alto rendimiento MBEC, a concentraciones de 1, 0.1 y 0.01 μg/ml y clorhexidina como control positivo. La citotoxicidad de los compuestos se evaluó sobre queratinocitos y fibroblastos, mediante la técnica de reducción de MTT, utilizando 0.5 mM de H2O2 como control de muerte celular (control negativo) y etanol 1 % como control del vehículo (control positivo). Las tres sustancias evaluadas, tuvieron efectos sobre la viabilidad bacteriana de S. mutans con una mortalidad entre 74 y 96 %, sin diferencia significativa entre ellos (P > 0.393); adicionalmente, no fue evidente la citotoxicidad sobre queratinocitos y fibroblastos en un tratamiento de 24 h. Las sustancias evaluadas mostraron efectos antimicrobianos significativos; por lo tanto, estos deben estudiarse más a fondo como posibles coadyuvantes para prevenir la caries dental que causa efectos adversos menores.(AU)

Abstract Dental caries is a pathology of multifactorial origin and currently natural products are an efficient alternative treatment. The work sought to evaluate the antimicrobial activity of the three substances (Cymbopogon citratus essential oil and the citral and myrcene components) against Streptococcus mutans ATCC UA159, as well as their cytotoxicity on keratinocytes and human fibroblasts. Through Scanning electron microscopy, the typical morphology of S. mutans was observed and, a characteristic formation of polysaccharides, with more structured arrangement at 48 h. The bacterial viability effect against S. mutans on biofilms was evaluated through exposure to the three substances by using the MBEC technique-high-throughput at concentrations of 1, 0.1, and 0.01 µg/mL and chlorhexidine as positive control. The cytotoxicity of the compounds was evaluated on keratinocytes and fibroblasts through the MTT reduction technique, using 0.5 mM H2O2 as cell-death control (negative control) and ethanol 1 % as vehicle control (positive control). The three substances evaluated had effects on the bacterial viability of S. mutans with mortality between 74 and 96 %, without significant difference among them (P > 0.393); additionally, no cytotoxicity was evident on keratinocytes and fibroblasts in a 24 h treatment. The substances evaluated showed significant antimicrobial effects; hence, these should be studied further as potential co-adjuvants to prevent dental caries that cause minor adverse effects.(AU)

Vigilancia tecnológica de plantas aromáticas: de la investigación a la consolidación de la agrocadena colombiana / Technological monitoring of aromatic plants: from research to the consolidation of the Colombian agro-chain

El sector de plantas aromáticas, medicinales y condimentarias reúne una amplia variedad de especies nativas e introducidas con potencial agroindustrial. Para contribuir al diagnóstico tecnológico del sector en Colombia y brindar elementos de planificación estratégica hacia mejores niveles de desarrollo e internacionalización, se priorizaron ciertas especies aromáticas en este artículo y se planteó una vigilancia tecnología del 2004 al 2014. Se hizo una búsqueda de artículos científicos y patentes en ocho bases de datos en el ámbito nacional, iberoamericano y mundial según temáticas priorizadas. Los datos se procesaron mediante Microsoft Excel, EndNote, Vantage Point (2014) y Thomson Data Analyzer. A nivel nacional, la temática más registrada fue el material de siembra y el mejoramiento genético, mientras que en Iberoamérica y el mundo, fue el efecto biocida. Los países líderes en investigaciones sobre las aromáticas vigiladas fueron Brasil, Colombia y Cuba. A nivel internacional, los líderes en producción científica en PubMed y Scopus fueron India, EE. UU., Brasil y Colombia. La tendencia mundial de patentes es creciente, y su principal enfoque es "Necesidades corrientes de la vida". En conclusión, la vigilancia tecnológica ofreció una visión global de avances y tendencias en investigación y desarrollo tecnológico en áreas temáticas vinculadas con las plantas aromáticas. Además, se identificaron posibles aliados investigativos y fluctuación de la producción científica a través del tiempo.