Enhancement of Strawberry Shelf Life via a Multisystem Coating Based on Lippia graveolens Essential Oil Loaded in Polymeric Nanocapsules.

Strawberries (Fragaria xannanasa) are susceptible to mechanical, physical, and physiological damage, which increases their incidence of rot during storage. Therefore, a method of protection is necessary in order to minimize quality losses. One way to achieve this is by applying polymer coatings. In this study, multisystem coatings were created based on polymer nanocapsules loaded with Lippia graveolens essential oil, and it was found to have excellent optical, mechanical, and water vapor barrier properties compared to the control (coating formed with alginate and with nanoparticles without the essential oil). As for the strawberries coated with the multisystem formed from the polymer nanocapsules loaded with the essential oil of Lippia graveolens, these did not present microbial growth and only had a loss of firmness of 17.02% after 10 days of storage compared to their initial value. This study demonstrated that the multisystem coating formed from the polymer nanocapsules loaded with the essential oil of Lippia graveolens could be a viable alternative to preserve horticultural products for longer storage periods.

Development of Essential Oil-Loaded Polymeric Nanocapsules as Skin Delivery Systems: Biophysical Parameters and Dermatokinetics Ex Vivo Evaluation.

Essential oils (EOs) are natural antioxidant alternatives that reduce skin damage. However, EOs are highly volatile; therefore, their nanoencapsulation represents a feasible alternative to increase their stability and favor their residence time on the skin to guarantee their effect. In this study, EOs of Rosmarinus officinalis and Lavandula dentata were nanoencapsulated and evaluated as skin delivery systems with potential antioxidant activity. The EOs were characterized and incorporated into polymeric nanocapsules (NC-EOs) using nanoprecipitation. The antioxidant activity was evaluated using the ferric thiocyanate method. The ex vivo effects on pig skin were evaluated based on biophysical parameters using bioengineering techniques. An ex vivo dermatokinetic evaluation on pig skin was performed using modified Franz cells and the tape-stripping technique. The results showed that the EOs had good antioxidant activity (>65%), which was maintained after nanoencapsulation and purification. The nanoencapsulation of the EOs favored its deposition in the stratum corneum compared to free EOs; the highest deposition rate was obtained for 1,8-cineole, a major component of L. dentata, at 1 h contact time, compared to R. officinalis with a major deposition of the camphor component. In conclusion, NC-EOs can be used as an alternative antioxidant for skin care.

Active Flavonoids from Colubrina greggii var. greggii S. Watson against Clinical Isolates of Candida spp.

Candida albicans is the most commonly implicated agent in invasive human fungal infections. The disease could be presented as minimal symptomatic candidemia or can be fulminant sepsis. Candidemia is associated with a high rate of mortality and high healthcare and hospitalization costs. The surveillance programs have reported the distribution of other Candida species reflecting the trends and antifungal susceptibilities. Previous studies have demonstrated that C. glabrata more frequently presents fluconazole-resistant strains. Extracts from Mexican plants have been reported with activity against pulmonary mycosis, among them Colubrina greggii. In the present study, extracts from the aerial parts (leaves, flowers, and fruits) of this plant were evaluated against clinical isolates of several species of Candida (C. albicans, C. glabrata, C. parapsilosis, C. krusei, and C. tropicalis) by the broth microdilution assay. Through bioassay-guided fractionation, three antifungal glycosylated flavonoids were isolated and characterized. The isolated compounds showed antifungal activity only against C. glabrata resistant to fluconazole, and were non-toxic toward brine shrimp lethality bioassay and in vitro Vero cell line assay. The ethyl acetate and butanol extracts, as well as the fractions containing the mixture of flavonoids, were more active against Candida spp.

Simultaneous GC-FID Quantification of Main Components of Rosmarinus officinalis L. and Lavandula dentata Essential Oils in Polymeric Nanocapsules for Antioxidant Application.

The essential oils (EO) of R. officinalis and L. dentata have been widely used due to their antioxidant activity. However, due to their high volatility, the loading of EO into polymeric nanocapsules (NC) represents an efficient way of retaining their effect in future topical administration. In this way, the quantitative determination of EO incorporated into NC is necessary for simultaneous monitoring of the main components of the EO during the nanoencapsulation process as well as for precise and exact dosing of the components used during the performance of in vitro and in vivo biological tests. In this study, EO were isolated by hydrodistillation in a Clevenger-type apparatus and characterized by GC-MS and GC-FID analyses. The major constituents of EO-R. officinalis were camphor (39.46%) and 1,8-cineole (14.63%), and for EO-L. dentata were 1,8-cineole (68.59%) and ß-pinene (11.53%). A new analytical method based on GC-FID for quantification of free and encapsulated EO was developed and validated according to ICH. Linearity, limit of detection and quantification, and intra- and interday precision parameters were determined. The methods were linear and precise for the quantification of the main components of EO. The EO were encapsulated by nanoprecipitation and were analyzed by the GC-FID method validated for their direct quantification. The NC size was 200 nm with homogeneous size distribution. The quantification of the incorporated EO within a NC is an important step in NC characterization. In this way, an encapsulation efficiency of at least 59.03% and 41.15% of total EO-R. officinalis and EO-L. dentata, respectively, was obtained. Simple, repeatable, and reproducible methods were developed as an analytical tool for the simultaneous quantification of the main components of EO loaded in polymeric nanocapsules as well as their monitoring in biological assays.

Screening of north-east Mexico medicinal plants with activities against herpes simplex virus and human cancer cell line.

The plants examined in this study have previous biological activity reports indicating the possibility of found activity against herpes and cancer cell. The aim of this contribution was to carry out a screening of Juglans mollis (Juglandaceae), Persea americana (Lauraceae), Hamelia patens (Rubiaceae), Salvia texana (Lamiaceae), Salvia ballotaeflora (Lamiaceae), Ceanothus coeruleus (Rhamnaceae), Chrysactinia mexicana (Asteraceae) y Clematis drummondii (Ranunculaceae), against HeLa cells, VHS-1 and VHS-2. The method MTT was used to determine the 50% cytotoxic concentration (CC50), in Vero and HeLa cell lines. To determine the 50% inhibitory concentration (IC50) against herpes, the plaque reduction method was used. Results showed that none of the plants exhibited activity against HeLa cells. About antiherpetic activity, J. mollis and S. ballotaeflora extracts present antiherpetic activity in terms of their SI, increasingly interest for further studies on the isolation of compounds with antiherpetic activity and about the mechanisms of action that produce this activity.

Essential oils from Zanthoxylum fagara Wild Lime, Ruta chalepensis L. and Thymus vulgaris L.: Composition and activity against Aedes aegypti larvae.

The dengue virus is transmitted by Aedes aegypti. Several plants are used to control this mosquito. In the present study the chemical composition of the essential oils of Ruta chalepensis, Zanthoxylum fagara and Thymus vulgaris were analyzed, and their activities against larvae of two A. aegypti populations were evaluated. The major compounds found in T. vulgaris were thymol and -cymene at 39.8% and 30.5%, respectively, with the major components being oxygenated monoterpenes and monoterpene hydrocarbons at 55.5% and 40.4%, respectively. For Z. fagara, the major compounds were sylvestrene and E-caryophyllene at 25.3% and 23.6%, respectively, with the major components being sesquiterpene and monoterpene hydrocarbons at 51.1% and 37.5%, respectively. Ketones were the predominant group of compounds found in R. chalepensis, with the major components being 2-undecanone and 2-nonanona at 43.7% and 35.4%, respectively. Essential oils from T. vulgaris, Z. fagara and R. chalepensis showed activity against larvae of the A. aegypti New Orleans strain, producing median lethal concentrations (LC50) of 2.14, 27.57 and 2.69 g/mL, respectively, at 24 h. LC50 values produced against larvae of a local A. aegypti population in Nuevo Leon, México, were 25.37, 60.42 and 20.13 g/mL, respectively, at 24 h.

Antimicrobial and antioxidant activities and chemical characterization of essential oils of Thymusvulgaris, Rosmarinus officinalis, and Origanum majorana from northeastern México.

There have been no reports of antifungal activity and composition of extracts from Thymus vulgaris, Rosmarinus officinalis or Origanum majorana from northeastern México. Antifungal activity of these oils against Trichophyton rubrum, Trichophyton tonsurans, Trichophyton mentagrophytes, Microsporum gypseum, Microsporum canis and Epidermophyton floccosum was measured by diffusion assay. Additionally, antibacterial and antioxidant activities were evaluated. Antibacterial activity against Staphylococcus aureus and Streptococcus pyogenes was examined by microdilution. Antioxidant activity was assessed by 2,2-difenil-1-picrilhidracil reduction test. The plant oils were characterized by both GC/MS and GC/FID. Oils of T. vulgaris and O. majorana showed growth inhibition activity against dermatophytes, especially T. vulgaris oil, which completely inhibited growth of all tested dermatophytes. The oils also showed bioactivity against bacteria, with minimum inhibitory concentration (MIC) values between 62.5 and 500 µg/mL. The antioxidant activity of the oils was low, with effective concentration (EC50) values <250µg/mL. The major components in the oils were as follows: T. vulgaris, o-cymene, µ-terpinene, thymol and carvacrol; R. officinalis, terpinen-4-ol and 1,8-cineole; O. majorana, terpinen-4-ol and thymol.

Chemical compositions and antimicrobial and antioxidant activities of the essential oils from Magnolia grandiflora, Chrysactinia mexicana, and Schinus molle found in northeast Mexico.

The essential oils from Magnolia grandiflora and Chrysactinia mexicana leaves, and from Schinus molle leaves and fruit, were characterized by gas chromatography/flame-ionization detection and gas chromatography/mass spectrometry. Twenty-eight compounds from M. grandiflora leaves were identified (representing 93.6% of the total area of the gas chromatogram), with the major component being bornyl acetate (20.9%). Colorless and yellow oils were obtained from the C. mexicana leaves with 18 (86.7%) and 11 (100%) compounds identified, respectively. In both fractions, the principal component was sylvestrene (36.8% and 41.1%, respectively). The essential oils ofS. molle leaves and fruit were each separated into colorless and yellow fractions, in which 14 (98.2) and 20 (99.8%) compounds were identified. The main component was alpha-phellandrene in all fractions (between 32.8% and 45.0%). The M. grandiflora oil displayed antifungal activity against five dermatophyte strains. The oils from S. molle and M. grandiflora leaves had antimicrobial activity against Staphylococcus aureus and Streptococcus pyogenes, which cause skin infections that potentially may lead to sepsis. However, the antioxidant activities of all oils were small (half maximal effective concentration values >250 microg/mL).

Activity against Streptococcus pneumoniae of the essential oil and 5-(3-buten-1-ynyl)-2, 2'-bithienyl isolated from Chrysactinia mexicana roots.

The essential oil of Chrysactinia mexicana retrieved from the root bark was characterized by gas chromatography coupled to a mass detector. The compounds silphiperfol-5-ene, 7-epi- silphiperfol-5-ene, modheph-2-ene, alpha-isocomene, beta-isocomene and methyl-linoleate were identified. The principal compound (76.42%) could not be identified by the library and was further isolated through a reverse phase C-18 chromatography followed by silica gel chromatography and identified as 5-(3-buten-1-ynyl)-2,2'-bithienyl. Both the oil and the isolated compound were tested for their antimicrobial activity against two strains of Streptococcus pneumoniae resistant to beta-lactam antibiotics. MICs were 250 microg/mL and 125 microg/mL respectively. This is the first report about extraction of oil and compound 5-(3-buten-1-ynyl)-2, 2'-bithienyl from roots of Chrysactinia mexicana as well as the determination of antimicrobial activity against S. pneumoniae.

Antimicrobial and antioxidant activities of plants from northeast of Mexico.

Traditional medicine has a key role in health care worldwide. Obtaining scientific information about the efficacy and safety of the plants from our region is one of the goals of our research group. In this report, 17 plants were selected and collected in different localities from northeast Mexico. The dried plants were separated into leaves, flowers, fruit, stems, roots and bark. Each part was extracted with methanol, and 39 crude extracts were prepared. The extracts were tested for their antimicrobial activity using three Gram-negative bacterial strains (Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii), three Gram-positive bacterial strains (Enterococcus faecalis and two Staphylococcus aureus strains), and seven clinically isolated yeasts (Candida albicans, C. krusei, C. tropicalis, C. parapsilosis and C. glabrata); their antioxidant activity was tested using a DPPH free radical assay. No activity against Gram-negative bacteria was observed with any extract up to the maximum concentration tested, 1000 µg ml(-1). We report here for the first time activity of Ceanothus coeruleus against S. aureus (flowers, minimal inhibitory concentration (MIC) 125 µg ml(-1)), C. glabrata (MICs 31.25 µg ml(-1)) and C. parapsilosis (MICs between 31.25 and 125 µg ml(-1)); Chrysanctinia mexicana against C. glabrata (MICs 31.25 µg ml(-1)); Colubrina greggii against E. faecalis (MICs 250 µg ml(-1)) and Cordia boissieri against C. glabrata (MIC 125 µg ml(-1)). Furthermore, this is the first report about antioxidant activity of extracts from Ceanothus coeruleus, Chrysanctinia mexicana, Colubrina greggii and Cyperus alternifolius. Some correlation could exist between antioxidant activity and antiyeast activity against yeasts in the species Ceanothus coeruleus, Schinus molle, Colubrina greggii and Cordia boissieri.