Differential expression of brummer and levels of TAG in different developmental stages Aedes aegypti (Diptera: Culicidae), including fasted adults.

Lipid storage in the form of triacylglycerol (TAG) is essential for insect life, as it enables flight, development, and reproduction. The activity of the lipase brummer (bmm) has been shown to be essential to insects' homeostasis. The objective of this study was to evaluate how bmm expression occurs in Aedes aegypti larvae and adults, and to observe TAG levels during fasting in adult females. The bmm sequence was identified in A. aegypti and exhibited a patatin-like phospholipase domain reinforced by the presence of a catalytic dyad with serine and aspartate residues, revealing a high degree of similarity with other organisms. Bmm expression was differentiated in the larvae and adult fat body (FB) following TAG reserve dynamics. Bmm was expressed three times in larval stages L3, L4, and pupae compared with L1 and L2, which could indicate its role in the maturation of these insects. In the postemergence (PE) and post-blood meal (PBM) FB of adult insects, bmm expression varied over several days. PE adults showed a pronounced bmm increase from the third day onward compared with those not subjected to fasting. This was accompanied by a decrease in TAG from the third day onward, suggesting the participation of bmm. Six hours after blood feeding, TAG levels increased in mosquitos reared in the absence of sucrose, suggesting lipid accumulation to guarantee reproduction. Bmm responded positively to fasting, followed by TAG mobilization in adult FB. During the previtellogenic period, bmm levels responded to low TAG levels, unlike the PBM period.

Larvicidal and Fungicidal Activity of the Leaf Essential Oil of Five Myrtaceae Species.

Myrtaceae is one of the most diverse and abundant botanical families, exhibiting wide diversity in the chemical composition of essential oils (EOs). EOs have various biotechnological applications such as controlling the populations of organisms that negatively impact humans. This study aimed to extract EOs from Myrtaceae species, chemically characterize them, and evaluate their larvicidal and fungicidal effects. EOs were extracted from the leaves of Eugenia brasiliensis, Eugenia uniflora, Psidium cattleyanum, Psidium guajava, and Syzygium cumini by hydrodistillation for 3 h and characterized by chromatographic analysis. Larvaes of Aedes aegypti and colonies of Fusarium oxysporum were subjected to increasing EO concentrations to determine the larvicidal and fungicidal potential. The EOs of Eugenia and Psidium species are primarily composed of sesquiterpenes (>80 %), whereas S. cumini EO is rich in monoterpenes (more than 60 %). The Eugenia species had similar amounts of oxygenated monoterpenes, which may explain their higher larvicidal potential compared to other species, with CL50 of 86.68 and 147.46 PPM, respectively. In addition to these two study species, S. cumini showed a high inhibition of fungal growth, with more than 65 % inhibition. We demonstrated that the actions of five EOs from Myrtaceae with different biological activities are associated with chemical diversity.

Acaricidal activity of a 2-methoxy-clovan-9-ol rich fraction from Eugenia copacabanensis (Myrtaceae) extract on Rhipicephalus microplus (Acari: Ixodidae).

Rhipicephalus microplus (Ixodidae, canestrini, 1888) is an invasive ectoparasite of cattle which causes high economic losses in emerging countries such as Brazil. Phytochemical compounds have been tested as an alternative to synthetic acaricides due to potentially lower mammalian toxicity. This study evaluated the acaricidal activity against R. microplus of the 2-methoxy-clovan-9-ol rich fraction obtained from Eugenia copacabanensis Kiaersk.leaves, a little known Myrtaceae species from the Brazilian Atlantic Forest. This fraction was obtained by maceration with methanol, partition with n-hexane and purification by normal-phase column chromatography. GC-MS, 1H and 13C NMR and IR analysis contributed to the identification of a major compound as the sesquiterpene 2-methoxy-clovan-9-ol, reported for the first time for the Myrtaceae family. The fraction was tested against R. microplus unfed larvae and engorged females and a 93% larval mortality was observed at the concentration of 50 mg mL-1. Lower concentrations of the solution tested demonstrated a significant difference in egg mass weight, hatching and control percentage. Experiments with 50.0 mg mL-1 showed significative results, with lower concentration and maximum efficacy for both assays. The IC50 values for unfed larvae and engorged females were 21.76 and 11.13 mg mL-1, respectively. These results were similar to those obtained in other studies with isolated botanical compounds and essential oils. The lower IC50 for engorged females than for unfed R. microplus larvae had also been described for other plant materials, including plants from the same Myrtaceae family. The present result suggested different mechanisms of action of the compound on the reproductive biology of engorged females, improving its effect against egg viability. These results are important for tick control, suggesting that 2-methoxy-clovan-9-ol could be a potential natural acaricidal product against both R. microplus unfed larvae and engorged females.

Myrcia eriopus DC. (Myrtaceae) fruits, a new endemic Brazilian source of bioactive anthocyanins.

Myrcia eriopus DC. (Myrtaceae) is a native and endemic Brazilian species, and there is no information about its chemical composition. In our study, five different anthocyanins and two other phenolic compounds were described for the first time in M. eriopus fruits. Delphinidin 3-O-glucoside (1), cyanidin 3-O-glucoside (2), petunidin 3-O-glucoside (3), peonidin 3-O-glucoside (4), malvidin 3-O-glucoside (5), gallic acid (6) and myricetin (7) were identified by offline system RP-HPLC-DAD/ESI-QTOF-MS and compared to the scientific literature. Furthermore, the lyophilized powder of M. eriopus fruits showed a high anthocyanin content (1878.14 mg cy-3-glu eqv/100 g f.w.), with greater levels of compounds 1 and 3, and an antioxidant potential in DPPH and ABTS assays (EC50 2419 µg/mL and 339 µmol Trolox/g f.w.), results superior to other non-conventional Brazilian fruits. This first report about the chemical composition of M. eriopus fruit reveals the potential of this fruit as a new source of bioactive anthocyanins.

Application crude multienzyme extract from Aspergillus niger as a pretreatment for the extraction of essential oil from Croton argyrophyllus leaves.

Leaves of Croton argyrophyllus contain essential oil with promising active components for the development of drugs and botanical insecticides. In this study, we evaluated the enzymatic pretreatment process to increase the extraction of essential oil from fresh and dried leaves of C. argyrophyllus. Pretreatment was carried out using a crude multienzymatic extract obtained via solid-state fermentation of forage palm by Aspergillus niger, and the extraction was performed by hydrodistillation. A Doehlert matrix was used to optimize the enzymatic pretreatment variables temperature and enzymatic extract. The effect of pretreatment time was also investigated. At optimum experimental conditions, 41.34°C, 140 min, and 130.73 mL of enzyme in 369.27 mL of water, the essential oil yield from fresh leaves subjected to enzymatic pretreatment increased by 9.35% and that from dry leaves by 6.77%. Based on chromatographic analysis (GC-MS), no compound was degraded in the extraction process. Micromorphological analysis confirmed the rupture of the glandular trichomes, favoring essential oil release. Therefore, enzymatic pretreatment associated with hydrodistillation increased the essential oil yield and is a promising application to obtain essential oil for therapeutic purposes without altering its composition.

The effect of the biflavonoid 2″,3″-dihydroochnaflavone on Trypanosoma cruzi Y strain.

Trypanosoma cruzi is the causative agent of Chagas disease which affects 8 million people in Latin America. The parasite possesses high capacity to evade host immune system and the available drugs to treat Chagas disease present low efficacy combined to serious side effects to patients. Therefore, the identification of alternative therapeutics is essential. Brazilian flora exhibits an immense diversity of metabolites with great potential to be developed into new drugs. We investigated the action of 2″,3″-dihydroochnaflavone a biflavonoid extracted from Luxemburgia nobilis Eichler ex Engl. (Ochnaceae) against T. cruzi (Y strain). Our experiments showed that this compound is effective against parasite epimastigote forms, presenting IC50 value of (2.5 ± 0.1) µM after 96 h of treatment. Ultrastructure alterations were also detected in treated epimastigotes especially mitochondrial enlargement at the kinetoplast region. At the concentration of 30 µM, the compound killed (61.6 ± 3.37)% of the parasite in its amastigote form. In addition, at the same concentration, the compound killed all trypamastigotes growing within murine macrophages after 7-9 days of infection. Nonetheless, the biflavonoid concentrations were harmless to murine enriched population of lymphocytes and peritoneal macrophages. These results indicate that 2″,3″- dihydroochnaflavone presents activity against T. cruzi.

Encapsulation of the black pepper (Piper nigrum L.) essential oil by lactoferrin-sodium alginate complex coacervates: Structural characterization and simulated gastrointestinal conditions.

Black pepper essential oil (EO) was encapsulated by complex coacervation with lactoferrin and sodium alginate using transglutaminase as a cross-linking agent. The encapsulation efficiency varied from 31.66 to 84.48%. Chemical and morphological characteristics suggest that the EO was encapsulated in a lactoferrin/sodium alginate shell. The chemical composition of the encapsulated EO was identified by gas chromatography (GC) and nuclear magnetic resonance (NMR). The GC and NMR analyses indicated good core protection with the materials used. The stability of the black pepper EO capsules under in vitro digestion was evaluated. Theses capsules demonstrated the low release of the EO during gastric digestion and higher release in intestinal digestion. These results suggest that these capsules can be used to transport active ingredients and that they are resistant to oral and gastric conditions that were tested in vitro.

Microencapsulation of sacha inchi oil (Plukenetia volubilis L.) using complex coacervation: Formation and structural characterization.

In this study, sacha inchi oil (SIO) (Plukenetia volubilis L.) was microencapsulated via complex coacervation of ovalbumin (OVA) and sodium alginate (AL), and the microcapsule properties were characterized. The omega-3 content in the SIO was evaluated after in vitro gastric simulation and microencapsulation. The coacervate complex between OVA and AL was evaluated based on electrostatic interactions and developed for use as a wall material via the SIO microencapsulation process. The best mass ratio for the biopolymers (OVA:AL) was 4:1 at pH 3.8, and the complex exhibited a thermal resistance at 189.86 °C. The SIO microcapsules showed a high encapsulation efficiency of approximately 94.12% in the ratio (OVA:AL) of 1:1. Furthermore, microencapsulated SIO presented resistance under gastric conditions with a low release of acyl (ω-3) units. These results demonstrate that it is possible to use OVA:AL as encapsulating agents to protect bioactive compounds and to improve the thermal behavior of microcapsules.

Antibiofilm activity of the essential oil of citronella (Cymbopogon nardus) and its major component, geraniol, on the bacterial biofilms of Staphylococcus aureus.

Medicinal plants with antimicrobial action have been investigated for uses against biofilms, among which, Cymbopogon nardus, citronella, stands out as a promising species. The present study aims to evaluate the antimicrobial and antibiofilm action of the essential oil of C. nardus (EOCN) and geraniol on Gram-negative and positive bacteria from the determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration and inhibition of biofilms. In the results, the EOCN produced a 41 mm halo on S. aureus, which was susceptible with MIC values of 0.5 and 0.25 mg/mL for the EOCN and geraniol respectively, both with bactericidal effect. The antibiofilm action was confirmed, the EOCN and geraniol reduced the biofilm biomass of S. aureus up to 100% between 0.5 and 4 mg/mL concentrations. The reduction of cell viability was 0.25 and 1 mg/mL, of EOCN and geraniol, respectively. EOCN and geraniol were shown to be promising antibiotic against S. aureus.

Physicochemical, thermal and rheological properties of synthesized carboxymethyl tara gum (Caesalpinia spinosa).

Carboxymethyl tara gum (CMTG) was synthesized from the reaction between tara gum (TG) and monochloroacetic acid (MCA) in the presence of sodium hydroxide. The modification reaction was optimized in terms of the MCA/NaOH ratio, reaction time and temperature evaluated for degree of substitution (DS). The etherification was confirmed by FTIR and 13C NMR spectroscopy, and it was characterized by different analyses. After carboxymethylation, CMTG showed new bonds at 1592, 1413 and 1320 cm-1 by FTIR and a new peak at δ = 178 ppm by 13C NMR in response to the insertion of the carbonyl group. The microscopy showed higher degradation on the surface of the CMTG particles, and XRD indicated low crystallinity of the CMTG. Static light scattering demonstrated a reduction in the molar mass of tara gum after carboxymethylation. Thermal analysis (TGA and DSC) revealed a lower thermal stability of carboxymethylated gum compared to that of unmodified gum. Despite the insertion of negative charges demonstrated by the potential-zeta, CMTG and TG presented pseudoplastic behavior according to the rheological analyses, and CMTG presented lower viscosity at the concentrations that were studied.

Dammarane-type triterpenoids from the stem of Ziziphus glaziovii Warm. (Rhamnaceae).

Seven undescribed dammarane-type triterpenoids, together with ten known compounds, were isolated from the stems of Ziziphus glaziovii Warm (= Sarcomphalus glaziovii (Warm.) Hauenschild). The structures were fully assigned by means of uni- and bidimensional NMR and HR-ESI-MS experiments. Extract, fractions and also isolated compounds were evaluated for their antibacterial (against Bacillus subtilis and Aliivibrio fischeri), cytotoxic (against PC-3 and HT-29 human cancer cell lines), anthelmintic (against Caenorhabditis elegans) and antifungal (against Septoria triciti, Botrytis cinerea and Phytopthoria infestans) activities. The methanolic crude extract exhibited substantial antibacterial and cytotoxic activity. The known triterpenes epigouanic acid and alphitolic acid were the most active compounds against B. subtilis, with IC50 of 12 and 22 µM, respectively. The isolated compounds presented up to a concentration of 10 µM none or only weak effects in the cytotoxicity assays. No anthelminthic and antifungal activities were observed.

Antimycobacterial and Nitric Oxide Production Inhibitory Activities of Triterpenes and Alkaloids from Psychotria nuda (Cham. & Schltdl.) Wawra.

A phytochemical study of leaves and twigs of Psychotria nuda resulted in 19 compounds, including five indole alkaloids, N,N,N-trimethyltryptamine, lyaloside, strictosamide, strictosidine, and 5α-carboxystrictosidine; two flavonolignans, cinchonain Ia and cinchonain Ib; an iridoid, roseoside; a sugar, lawsofructose; a coumarin, scopoletin; a diterpene, phytol; three triterpenes, pomolic acid, spinosic acid, and rotungenic acid; and five steroids, sitosterol, stigmasterol, campesterol, ß-sitosterol-3-O-ß-d-glucoside, and ß-stigmasterol-3-O-ß-d-glucoside. Some compounds were evaluated for their in vitro activity against Mycobacterium tuberculosis and their ability to inhibit NO production by macrophages stimulated by lipopolysaccharide (LPS). The compounds pomolic acid, spinosic acid, strictosidine, and 5α-carboxystrictosidine displayed antimycobacterial activity with minimum inhibitory concentrations ranging from 7.1 to 19.2 µg/mL. These compounds showed promising inhibitory activity against NO production (IC50 3.22 to 25.5 µg/mL). 5α-carboxystrictosidine did not show cytotoxicity against macrophages RAW264.7 up to a concentration of 100 µg/mL. With the exception of strictosamide, this is the first report of the occurrence of these substances in P. nuda.

New compounds of Siolmatra brasiliensis and inhibition of in vitro protein glycation damage.

Twenty compounds were isolated from the hydroethanolic extract of the stems of Siolmatra brasiliensis, five flavonoids, two lignans, one glucosyl phytosterol, seven nor-cucurbitacins, one new phenolic derivative named siolmatrin (1) and four new dammarane-type saponins named siolmatrosides II-V (2-5), the structures of the compounds were assigned by means of 1D and 2D NMR experiments and HRESIMS of the natural compounds and some acetyl derivatives. The effects of the crude hydroethanolic extract (SbExt) and the ethyl acetate fraction (SbEtAc) of Siolmatra brasiliensis stems on the formation of advanced glycation end-products (AGEs) were also investigated. In the in vitro model system of protein glycation using bovine serum albumin (BSA) and glucose, addition of SbExt or SbEtAc inhibited the formation of fluorescent AGEs, in parallel to minor levels of fructosamine (SbEtAc) and markers of tyrosine and tryptophan oxidation (SbExt and SbEtAc). Protein crosslinking, which represents changes of late stages of protein glycation, was reduced in the presence of SbExt and SbEtAc. Siolmatra brasiliensis stems seem to be a promising source of compounds having ability to prevent glycoxidation changes, arising as an interesting option to be studied as a complementary therapy for complications of diabetes.

Chemical and Biological insights of Ouratea hexasperma (A. St.-Hil.) Baill.: a source of bioactive compounds with multifunctional properties.

The study aimed to evaluate in vitro antioxidant, anticholinesterase and antidiabetic properties of Ouratea hexasperma (A. St.-Hil.) Baill. The inflorescence methanol extract and the ethyl acetate fraction of leaves and stems reported the highest Relative Antioxidant Capacity Index (RACI), whereas the dichloromethane fraction of leaves was the best inhibitor of α-amylase and α-glucosidase. Trans-3-O-methyl-resveratrol-2-C-ß-glucoside, lithospermoside, 2,5-dimethoxy-p-benzoquinone, lup-20(30)-ene-3ß,28-diol, 7-O-methylgenistein, apigenin and luteolin and amentoflavone were isolated from O. hexasperma. Resveratrol derivative was isolated for the first time in Ochnaceae family. Luteolin, followed by apigenin, reported the highest Relative Antioxidant Capacity Index and they were also the best inhibitors of α-glucosidase enzyme.

In vitro assessment of the acaricidal activity of carvacrol, thymol, eugenol and their acetylated derivatives on Rhipicephalus microplus (Acari: Ixodidae).

This study reports the comparative evaluation of the activity of carvacrol, thymol, eugenol and their respective acetylated derivatives (carvacrol acetate, thymol acetate and eugenol acetate) on Rhipicephalus microplus, to verify the possible influence of the acetate group. The acetylated derivatives were prepared from reactions of the phenolic compounds with acetic anhydride/pyridine. The formation of the products was confirmed by analysis of hydrogen and carbon-13 nuclear magnetic resonance (1H and 13C NMR) spectra. The larval packet test was used to evaluate the acaricidal activity, with concentrations of 0.312, 0.625, 1.25, 2.5, 5.0, 7.5, 10.0 and 15.0 mg/mL. Thymol and carvacrol resulted in 100% mortality starting at the concentration of 2.5 mg/mL, while the same was observed for carvacrol acetate starting at the concentration of 5.0 mg/mL. For the other treatments, 100% mortality was only achieved in the groups treated with the highest concentration (15.0 mg/mL). The LC50 and LC90 values (mg/mL) of carvacrol acetate (2.49, 4.21), thymol acetate (2.97, 8.52) and eugenol acetate (4.25, 13.10) were higher than those for the corresponding precursor molecules carvacrol (0.83, 2.02), thymol (1.26, 2.21) and eugenol (2.77, 5.35). The acetylation process did not enhance the activity of these substances on unengorged larvae of R. microplus, since the precursor substances (carvacrol, thymol and eugenol) had greater efficacy.

Effect of xanthan gum or pectin addition on Sacha Inchi oil-in-water emulsions stabilized by ovalbumin or tween 80: Droplet size distribution, rheological behavior and stability.

The aim of this work was to studied the formation, stability and characterization of oil-in-water emulsions formed by Sacha Inchi oil (SIO) 8% (w/w) with either ovalbumin (Ova) or Tween 80 (Tw80), as emulsifiers at 0.5%-2.0% (w/w) and stabilized with pectin (Pec) at 1.0%-3.0% (w/w) or xanthan gum (XG) at 0.25%-1.0% (w/w). The emulsions were evaluated at 0, 1, 7 and 14 days after preparation and kept at a temperature of 25 ±â€¯1 °C for the ζ-potential, particle size distribution, polydispersion, and emulsion stability index measurements. The emulsions were characterized by optical microscopy, viscosity and rheological behavior. It was observed that it is possible to form oil-in-water emulsions with SIO-Ova and Pec that are stable at 25 °C for at least 14 days with a polydispersion value between 0.2 and 0.5. However, the emulsions with SIO-Ova and XG are stable at several concentrations of XG but are more viscous and can form aggregates. The presence of a biopolymer is essential for the kinetic stability of the emulsions containing Ova as the emulsifier. For the emulsions containing Tw80, this conclusion applies only to emulsions with XG concentrations of 0.5% to 1.0%, in which the stability mechanism is distinct.

Activity of the extract of Acmella oleracea on immature stages of Amblyomma sculptum (Acari: Ixodidae).

This study evaluated the acaricidal activity of the methanol extract of Acmella oleracea with 0.187% of spilanthol against immature stages of Amblyomma sculptum. The packet test was used to evaluate the extract's activity on unengorged larvae and nymphs, testing concentrations of 0.4 to 50 mg/mL for larvae and 12.5 to 200.0 mg/mL for nymphs. For the engorged stages, the immersion test was used, at concentrations of 0.4 to 50 mg/mL for larvae and 12.5 to 200.0 mg/mL for nymphs. The methanol extract caused 100% mortality of the unengorged larvae and nymphs starting at concentrations of 12.5 and 200.0 mg/mL, respectively. For engorged larvae and nymphs, the mortality was 100% starting from concentrations of 12.5 and 150.0 mg/mL, respectively. The LC50 for unengorged larvae was 3.2 mg/mL, while for engorged larvae it was 6.6 mg/mL. For unengorged nymphs, the LC50 was 38.5 mg/mL, but it was not possible to calculate the corresponding value for engorged nymphs because the data did not fit the probit model. These results demonstrate that the methanol extract of A. oleracea has acaricidal activity against different immature stages of A. sculptum.

Plectranthus amboinicus essential oil and carvacrol bioactive against planktonic and biofilm of oxacillin- and vancomycin-resistant Staphylococcus aureus.

BACKGROUND: The emergence of multidrug-resistant bacteria is a worldwide concern and in order to find an alternative to this problem, the occurrence of antimicrobial compounds in Plectranthus amboinicus essential oil was investigated. Thus, this study aims to determine susceptibility of Staphylococcus aureus isolated from food to antibiotics, P. amboinicus essential oil (PAEO) and carvacrol. METHODS: Leaves and stem of P. amboinicus were used for extraction of essential oil (PAEO) by hydrodistillation technique and EO chemical analysis was performed by gas chromatography coupled to a mass spectrometer. S. aureus strains (n = 35) isolated from food and S. aureus ATCC 6538 were used to evaluate the antimicrobial and antibiofilm activity of PAEO and carvacrol. All strains (n = 35) were submitted to antimicrobial susceptibility profile by disk diffusion method. Determination of MIC and MBC was performed by microdilution technique and antibiofilm activity was determined by microtiter-plate technique with crystal violet assay and counting viable cells in Colony Forming Units (CFU). RESULTS: Carvacrol (88.17%) was the major component in the PAEO. Antibiotic resistance was detected in 28 S. aureus strains (80%) and 12 strains (34.3%) were oxacillin and vancomycin-resistant (OVRSA). From the 28 resistant strains, 7 (25%) showed resistance plasmid of 12,000 bp. All strains (n = 35) were sensitive to PAEO and carvacrol, with inhibition zones ranging from 16 to 38 mm and 23 to 42 mm, respectively. The lowest MIC (0.25 mg mL-1) and MBC (0.5 mg mL-1) values were observed when carvacrol was used against OVRSA. When a 0.5 mg mL-1 concentration of PAEO and carvacrol was used, no viable cells were found on S. aureus biofilm. CONCLUSION: The antibacterial effect of carvacrol and PAEO proves to be a possible alternative against planktonic forms and staphylococcal biofilm.

Microencapsulation of sacha inchi oil using emulsion-based delivery systems.

In this study, sacha inchi oil (SIO) was microencapsulated by emulsion-based systems using ovalbumin (Ova), pectin (Pec), and xanthan gum (XG), followed by freeze-drying. The microencapsulation was confirmed using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The stability of omega-3 in SIO alone as well as in microencapsulated SIO was assessed by nuclear magnetic resonance (1H NMR) spectroscopy after human gastric simulation (HGS). The SEM results revealed distinct structures for the two types of microcapsules. The thermograms showed that the thermal resistance was increased in the microencapsulated SIO, indicating that the emulsion-based system may be a way to protect the omega-3 in the SIO. In addition, the microencapsulation conferred an increased crystallinity degree, indicating a higher structural organization. Moreover, this method did not affect the stability of SIO, as confirmed by 1H NMR. The release of omega-3 acyl units from the SIO was correlated with the decrease of the methynic proton (sn, 2 position) of triacylglycerol (TAG). In contrast, the increase of 1,3-diglycerides was negatively correlated with the decrease of glyceryl groups (sn, 1,3 positions). The HGS conditions did not significantly alter the stability of the omega-3 of SIO over 180min. The SIO-Ova microcapsules had a similar behavior to the SIO, and the presence of Ova was not enough to prevent the decrease of omega-3 content over 180min. The SIO-Ova-Pec and SIO-Ova-XG microcapsules were shown to protect the omega-3 content effectively. In conclusion, the microcapsules developed in this study can be used to transport nutraceutical compounds because they are resistant to the human gastric conditions tested in vitro.

In Vitro Antibacterial and Antibiofilm Activity of Lippia alba Essential Oil, Citral, and Carvone against Staphylococcus aureus.

In vitro antimicrobial and antibiofilm activities of the Lippia alba essential oil and its major components (citral and carvone) against Staphylococcus aureus were investigated. Essential oils (LA1EO, LA2EO, and LA3EO) were extracted from the aerial parts of three L. alba specimens by hydrodistillation and analyzed by gas chromatography coupled to a mass spectrometer. Minimum Inhibitory Concentrations (MIC) and Minimum Bacterial Concentration (MBC) were determined by the microdilution method. For the antibiofilm assays, the biomass formation in the biofilm was evaluated by the microtiter-plate technique with the crystal violet (CV) assay and the viability of the bacterial cells was analyzed. All oils and their major components presented antibacterial activity, and the lowest MIC and MBC values were 0.5 mg mL-1 when LA1EO and citral were used. Potential inhibition (100%) of S. aureus biofilm formation at the concentration of 0.5 mg mL-1 of all EOs was observed. However, the elimination of biofilm cells was confirmed at concentrations of 1 mg mL-1, 2 mg mL-1, 2 mg mL-1, and 0.5 mg mL-1 for LA1EO, LA2EO, LA3EO, and citral, respectively. The results obtained in the present research point to the promising antibacterial and antibiofilm potential of L. alba EOs against S. aureus, a species of recognized clinical interest.