RESUMO
In recent years, lignin has drawn increasing attention due to its intrinsic antibacterial and antioxidant activities, biodegradability, and biocompatibility. Yet, like several other biogenic structures, its compositional heterogeneity represents a challenge to overcome. In addition, there are few studies regarding food applications of lignin. Herein, we evaluate the antimicrobial and antioxidant effects of lignin from two different sources. These lignins were characterized by attenuated total reflectance Fourier-transform infrared (ATR-FTIR) and hydrogen nuclear magnetic resonance (1H NMR) spectroscopies. Their antibacterial and antioxidant capacities (DPPH and Folin-Ciocalteu methods) were also investigated. Susceptibility tests were performed with the minimal inhibitory (MIC) and bactericidal (MBC) concentrations using the micro-broth dilution technique. Kraft lignin presented higher radical-scavenging and antibacterial activities than alkali lignin, indicating the dependence of antioxidant and antibacterial activities on the precursor biomass. Scanning electron microscopy shows morphologic changes in the bacteria after exposure to lignin, while confocal microscopy suggests that kraft lignin has affinity towards bacterial surfaces and the ability to cause cell membrane destabilization. Lignin inhibited the growth of Staphylococcus aureus and Salmonella Enteritidis in skimmed milk, herein taken as food model. Our results suggest that lignins are promising candidates for green additives to improve quality and safety within the food chain.
Assuntos
Antioxidantes , Lignina , Animais , Lignina/farmacologia , Lignina/química , Antioxidantes/farmacologia , Antioxidantes/química , Leite , Rios , Antibacterianos/farmacologiaRESUMO
Two trials were performed in order to evaluate the effects of dietary Kraft lignin inclusion on broiler performance, ileal nutrient digestibility, blood lipid profile, intestinal morphometry, and lipid oxidation of meat. Trial 1 was conducted in order to evaluate performance and ileal digestibility for the period of 1 to 21 d of age, randomly distributing 490 day-old broiler chicks across 5 dietary treatments with 14 replicates containing 7 birds each in metabolic cages, while trial 2 was executed in order to evaluate performance, blood parameters, intestinal morphometry, carcass yield and abdominal fat, and lipid oxidation for the period of 1 to 42 d of age, randomly distributing 900 day-old broiler chicks across 5 dietary treatments with 15 replicates of 12 birds each in floor pens, being each bird in trial 2 challenged with coccidiosis vaccine at 10 d of age. The treatments used in both trials were: positive control (PC): basal diet + antimicrobial; negative control (NC): Basal diet; NC1: NC + 1% lignin; NC2: NC + 2% lignin; NC3: NC + 3% lignin. For trial 1, it was observed that birds fed diets containing 1% lignin had a significant positive effect for BW, feed intake (FI), average daily weight gain (BWG) and feed conversion rate (FCR), similar to the PC, but also showing better EE, CP and AAs ileal digestibility percentages when compared to other treatments. For trial 2, it was observed that during the period of 21 to 35 d, the inclusion of lignin in the diet provided better results in animal performance, similar to the PC group, but at 42 d, animals fed with dietary lignin showed results lower than animals fed the PC diet (P < 0.05). Animals fed with increasing lignin concentrations showed decreasing levels of HDL (P < 0.05). As of intestinal morphometry, animals fed with 1% and 3% lignin showed longer intestinal length (P < 0.05). At 14 d of age, it was observed that animals fed with lignin showed oxidation levels similar to the control treatments. The inclusion of up to 1% lignin in the diet provides beneficial effects on productive performance and nutrient digestibility, while the inclusion of 2% lignin provided lower cholesterol levels, lower villus/crypt ratio, and better internal organ development, therefore, it can be considered an alternative to performance-enhancing antimicrobials in broiler chicken diets.
Assuntos
Galinhas , Suplementos Nutricionais , Animais , Triglicerídeos/farmacologia , Lignina/farmacologia , Digestão , Dieta/veterinária , Nutrientes , Colesterol , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição AnimalRESUMO
The cosmetics market has recently undergone changes as consumers increasingly seek sustainable products. In this context, agro-derived lignins have the potential for cosmetics applications. Thus, this study investigated the photoprotective activity and skin irritation potential (OECD TG 439 with SkinVitro-RHE, an in-house reconstructed human epidermis (RHE) model) of a kraft lignin (LE) and two LE-derived lignins modified by enzymatic reactions to achieve higher molecular weight (Mw) (R1: intermediate Mw and E60: highest Mw). Results showed that LE and R1 lignins present adequate photoprotective activity with averages Sun Protection Factor (SPF) of 33.8 ± 0.02 and 22.7 ± 0.04, respectively. The E60 also present adequate SPF (22.4 ± 0.2); however, due to its poor solubility, this lignin has potential application as a physical filter. In terms of safety, these lignins did not cause skin irritation or cellular and structural damage to the epidermis. Additionally, using an analysis based on the autofluorescence feature of lignin, no sign of the tested lignins was found in exposed RHE models, indicating that these three lignins did not penetrate the skin. Altogether, the results indicate a promising application of kraft lignins for sunscreen products regarding safer alternatives and product sustainability. Also, the SkinVitro-RHE showed to be a good model for evaluating the skin irritation potential of substances, including natural cosmetic ingredients.
Assuntos
Cosméticos , Lignina , Humanos , Lignina/farmacologia , Cosméticos/farmacologia , Epiderme , PeleRESUMO
In this work, we investigated in vitro the antioxidant, cytotoxic and anti-leishmanial activities of a lignin extracted from the leaves of Morinda citrifolia. Initially, an analysis of the composition of the sheets was performed, then the lignin was obtained by alkaline delignification and characterized by different techniques: elemental analysis, FT-R, UV-vis, HSQC-NMR, thermal analysis, Py-GC/MS and by GPC. The results showed that the leaves had in their composition cellulose (31.29%), hemicellulose (25.01%), lignin (18.34%), extractives (14.39%) and ash (10.03%). The lignin extraction yield was 89.8%. The lignin obtained is of the GSH type with the following contents 79.39%, 13.58% and 7.03% respectively. Furthermore, it is low molecular weight and thermally stable. It had a phenolic content of 93.3 mg GAE/g and low antioxidant activity. In macrophage cytotoxicity assays, it presented a CC50 of 31.0 µg/mL, showing less toxicity than amphotericin B. In assays against the promastigote forms of Leishmania amazonensis, lignin presented an IC50 of 29.56 µg/mL, a less effective concentration than amphotericin B (IC50 = 0.14 µg/mL). However, it was able to promote inhibition of the parasites, a fact confirmed by structural changes. These findings reinforce that M. citrifolia lignin is a promising macromolecule for use as an antiparasitic and antioxidant agent.
Assuntos
Antioxidantes , Antiprotozoários , Citotoxinas , Leishmania/crescimento & desenvolvimento , Lignina , Morinda/química , Folhas de Planta/química , Animais , Antioxidantes/química , Antioxidantes/farmacologia , Antiprotozoários/química , Antiprotozoários/farmacologia , Linhagem Celular , Citotoxinas/química , Citotoxinas/farmacologia , Avaliação Pré-Clínica de Medicamentos , Lignina/química , Lignina/farmacologia , CamundongosRESUMO
The potential use of nopal cladode flour (NC) as reinforcing/bioactive agent in cassava starch-based films was evaluated and compared with the use of propolis extract or lignin, which are commonly used for these purposes. Cassava starch-based films containing untreated NC (S-NC), NC treated at pH 12 (S-NC12), aqueous propolis extract at two different concentrations (SP1 or SP2), or lignin (S-L) were produced by the casting technique; glycerol was used as plasticizer. NC12 and NC affected the mechanical properties of the cassava starch-based film similarly as compared to propolis extract and lignin. Moreover, NC and NC12 had different performance as reinforcing and antioxidant agent in cassava starch-based film. Thus, S-NC12 film was more elongable (28.5 ± 6.5%), more hydrophobic (contact angle: 70.8° ± 0.1), less permeable to water vapor (0.8 ± 0.0 × 10-10 g·m-1·s-1·Pa-1) and had better antioxidant activity by ABTSâ¢+ (44.70 ± 0.3 µM Trolox·g-1 of film) than the S-NC film. SEM and TGA analysis of films showed that NC12 was better incorporated into the cassava starch matrix than NC, lignin and propolis extract. Overall, nopal cladode flour has potential use in the production of active biodegradable packaging for the food preservation with high oxidation rate.
Assuntos
Antioxidantes/farmacologia , Filmes Comestíveis , Aditivos Alimentares/farmacologia , Embalagem de Alimentos , Conservação de Alimentos , Lignina/farmacologia , Manihot , Opuntia , Própole/farmacologia , Amido/farmacologia , Antioxidantes/isolamento & purificação , Aditivos Alimentares/isolamento & purificação , Interações Hidrofóbicas e Hidrofílicas , Manihot/química , Opuntia/química , Amido/isolamento & purificaçãoRESUMO
There is a growing environmental concern in the world for replacing the traditional petroleum-based products. The aim of this work was to evaluate the structure - property relationship of banana peel lignins (BPLs) as antioxidant and antimicrobial agents by controlling the parameters of organosolv process. The milled banana peel was hydrolyzed using an aqueous acetic acid solution (70, 80 and 90% v/v) and 2.0% v/v HCl at 110 °C for 1, 2 and 3 h. BPLs were characterized by FTIR, 1H NMR, 1H13C HSQC, 31P NMR, GPC and TGA. The antioxidant capacity of BPLs was evaluated by DPPH, ABTS and H2O2 assays, comparing their performance with that of ascorbic and gallic acid. The antimicrobial activity of BPLs was evaluated against E. coli. The reaction time and acetic acid/water ratio had significant effects on the yield and purity of BPLs. The composition of organosolv solution also affected their total amount of hydroxyls (0.71-0.82 mmol g-1), Mw (2759-3954 g mol-1), Tonset (232-254 °C), antioxidant and antimicrobial activities. It can be concluded that the control of organosolv parameters can be a useful tool for tuning the structural features of lignins and to maximize their performance.
Assuntos
Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Lignina/farmacologia , Musa/química , Solventes/química , Temperatura , Bactérias/efeitos dos fármacos , Benzotiazóis/química , Compostos de Bifenilo/química , Fungos/efeitos dos fármacos , Peróxido de Hidrogênio/química , Concentração Inibidora 50 , Lignina/química , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Peso Molecular , Picratos/química , Soluções , Espectroscopia de Infravermelho com Transformada de Fourier , Ácidos Sulfônicos/química , TermogravimetriaRESUMO
Lignins are phenolic macromolecules that have several applications. In this work, we examine some biological activities of a lignin-like macromolecule isolated from the Crataeva tapia leaves, not yet studied to evaluate its potential applications in medicinal and cosmetic formulations. Lignin was obtained by alkaline delignification and its physical-chemical characterization was made by means of FT-IR, UV-Vis, NMR spectroscopy, elementary analysis, molecular mass determination and thermal analysis. Lignin is of the GSH type, with levels of hydrogen (5.10%), oxygen (27.18%), carbon (67.60%), nitrogen (0.12%) and phenolic content of 189.6 ± 9.6 mg GAE/g. In addition, it is a thermally stable macromolecule with low antioxidant activity. Cytotoxicity and cytokine production were assessed by flow cytometry. The photoprotective activity was evaluated by adding different concentrations of lignin to a commercial cream. Lignin was not cytotoxic, it stimulated the production of TNF-α, IL-6 and IL-10 and did not promote a significant change in nitric oxide levels. In addition, this macromolecule was able to promote increased absorption of ultraviolet light from a commercial cream. These results reinforce the ethnopharmacological use of C. tapia leaves and suggest the need for further studies to determine the potential medicinal and cosmetic applications (sunscreen) of lignin from C. tapia leaves.
Assuntos
Antioxidantes/química , Capparaceae/química , Lignina/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Protetores Solares/química , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Doadores de Sangue , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Cosméticos/química , Citocinas/biossíntese , Humanos , Lignina/isolamento & purificação , Lignina/farmacologia , Linfócitos/efeitos dos fármacos , Linfócitos/metabolismo , Peso Molecular , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Fenóis/análise , Extratos Vegetais/isolamento & purificação , Transdução de Sinais/efeitos dos fármacos , Absorção Cutânea/efeitos dos fármacos , Protetores Solares/isolamento & purificação , Protetores Solares/farmacologia , Raios UltravioletaRESUMO
In this work, we investigated the antioxidant and immunomodulatory activities of a lignin isolated from Conocarpus erectus leaves. The lignin was characterized by FTIR, 1H NMR, 13C NMR and gel permeation chromatography analysis as well as ultraviolet/visible absorption spectra. The lignin was evaluated for total antioxidant activity (TAA), DPPH and ABTS+ scavenging abilities, and by a lipid peroxidation inhibition assay. Immunomodulatory activity of the lignin (10 µg/mL) on human peripheral blood mononuclear cells (PBMCs) was determined. The C. erectus lignin was found to be of the guaiacyl-syringyl-p-hydroxyphenyl (G-S-H) type, with an average molecular weight of 2709 Da (polydispersity index: 2.1). It showed low TAA (17.92%) and moderate antioxidant activity against DPPH and ABTS+ (IC50: 231.16 and 356.03 µg/mL, respectively). It also inhibited lipid peroxidation by 42.14%. The lignin promoted an increase in mitochondrial ROS levels as well as cytosolic Ca2+ in PBMCs. In addition, it promoted the differentiation and activation of CD8+ T lymphocytes, differentiation of CD14+ monocytes, and stimulated the release of nitric oxide and cytokines, mainly those linked to a Th1 response. The results showed that the C. erectus lignin may be used in future studies in which the modulation of the immune response is a key factor.
Assuntos
Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Fatores Imunológicos/isolamento & purificação , Fatores Imunológicos/farmacologia , Lignina/isolamento & purificação , Lignina/farmacologia , Myrtales/química , Folhas de Planta/química , Antioxidantes/química , Proliferação de Células , Sobrevivência Celular , Citocinas/metabolismo , Humanos , Fatores Imunológicos/química , Imunofenotipagem , Peroxidação de Lipídeos , Estresse Oxidativo , Compostos Fitoquímicos/química , Espécies Reativas de Oxigênio/metabolismoRESUMO
OBJECTIVES: Major lignocellulosic inhibitory compounds found in sugarcane-based industrial hydrolysate samples were tested in laboratory and industrial yeast strains, as well as in lactic acid bacteria, in order to verify their effects on important physiological parameters. RESULTS: Saccharomyces cereviaise SA-1, an industrial strain, stood out as compared to the remaining strains for virtually all inhibitors investigated. This strain presented the highest growth rate and the lowest lag-phase in the presence of acetic acid, levulinic acid, p-coumaric acid, ferulic acid, and HMF, when compared to the other strains. In sugarcane-based hydrolysate fermentations, both SA-1 and CEN.PK113-7D presented similar fermentation performances. Industrial isolates of contaminating lactic acid bacteria were evaluated in the presence of an inhibitory cocktail, containing a mixture of 76.6 mM acetic acid, 1.3 mM HMF, 7.1 mM furfural, and 1.9 mM p-coumaric acid. Whilst all yeast strains were unable to grow under such conditions, bacteria had an average inhibition of roughly 50% on their growth rates. CONCLUSIONS: Overall, industrial strain SA-1 might be a promising microbial chassis for second generation ethanol production and for future metabolic and evolutionary engineering strategies, and for strain robustness understanding.
Assuntos
Lactobacillales/crescimento & desenvolvimento , Lignina/farmacologia , Saccharomyces cerevisiae/crescimento & desenvolvimento , Saccharum/química , Ácido Acético/metabolismo , Técnicas de Cultura Celular por Lotes , Etanol/metabolismo , Fermentação , Furaldeído/metabolismo , Hidrólise , Microbiologia Industrial , Lactobacillales/efeitos dos fármacos , Lignina/química , Extratos Vegetais/química , Saccharomyces cerevisiae/efeitos dos fármacosRESUMO
Polylactic acid (PLA) films containing 1 wt % and 3 wt % of lignin nanoparticles (pristine (LNP), chemically modified with citric acid (caLNP) and acetylated (aLNP)) were prepared by extrusion and characterized in terms of their overall performance as food packaging materials. Morphological, mechanical, thermal, UV-Vis barrier, antioxidant and antibacterial properties were assayed; appropriate migration values in food simulants and disintegration in simulated composting conditions were also verified. The results obtained indicated that all lignin nanoparticles succeeded in conferring UV-blocking, antioxidant and antibacterial properties to the PLA films, especially at the higher filler loadings assayed. Chemical modification of the fillers partially reduced the UV protection and the antioxidant properties of the resulting composites, but it induced better nanoparticles dispersion, reduced aggregates size, enhanced ductility and improved aesthetic quality of the films through reduction of the characteristic dark color of lignin. Migration tests and disintegration assays of the nanocomposites in simulated composting conditions indicated that, irrespectively of their formulation, the multifunctional nanocomposite films prepared behaved similarly to neat PLA.