scholarly journals In Situ Grafting of Silica Nanoparticle Precursors with Covalently Attached Bioactive Agents to Form PVA-Based Materials for Sustainable Active Packaging

Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2889
Author(s):  
Miri Klein ◽  
Anat Molad Filossof ◽  
Idan Ashur ◽  
Sefi Vernick ◽  
Michal Natan-Warhaftig ◽  
...  

Sustainable antibacterial–antioxidant films were prepared using in situ graftings of silica nanoparticle (SNP) precursors with covalently attached bioactive agents benzoic acid (ba) or curcumin (cur) on polyvinyl alcohol (PVA). The modified PVA-SNP, PVA-SNP-ba and PVA-SNP-cur films were characterized using spectroscopic, physicochemical and microscopic methods. The prepared films showed excellent antibacterial and antioxidant activity, and increased hydrophobicity providing protection from undesired moisture. The PVA-SNP-ba films completely prevented the growth of the foodborne human pathogen Listeria innocua, whereas PVA-SNP-cur resulted in a 2.5 log reduction of this bacteria. The PVA-SNP-cur and PVA-SNP-ba films showed high antioxidant activity of 15.9 and 14.7 Mm/g TEAC, respectively. The described approach can serve as a generic platform for the formation of PVA-based packaging materials with tailor-made activity tuned by active substituents on silica precursors. Application of such biodegradable films bearing safe bioactive agents can be particularly valuable for advanced sustainable packaging materials in food and medicine.

2021 ◽  
Vol 7 (1) ◽  
pp. 21-30
Author(s):  
Barış Karslı

The present study evaluated the effect of extraction techniques (ultrasound-assisted extraction (U) and shaking water bath extrac-tion (WB)), solvents (etha-nol, acetone and distilled water) and concentration (2.5% and 5%) on total phe-nolic content (TPC), anti-bacterial and antioxidant activities of extracts ob-tained from feijoa leaves, peel and pulp. The antibac-terial activity of feijoa ex-tracts were tested in vitro against 6 pathogens bacteria by the disc diffusion method and the antioxidant activity was evaluated by 2,2 diphe-nyl-1-picrylhydrazyl radical assay. The results indicated that leaves and peel extracts exhibited stronger antibac-terial activity than that of pulp. In generally, WB-A5%, WB-W5%, U-A5% and U-W 5% extracted with acetone (A) and water (W) at 5% concentration from feijoa leaves, peel and pulp showed more antibacterial activity against all tested pathogen bacteria. The leaves, peel, and pulp ex-tracts had high antioxidant activity with 85.78-90.82%, 89.86-91.60%, and 81.49-91.31%, respectively. Peel extracts had slightly higher antioxidant activity than leaves and pulp extracts. TPC of leaves, peel, and pulp extracts were in the range of 488.99-554.00, 349.17-517, and 115.64-345.46 mg gallic acid equivalents (GAE)/100 g of extract. The overall findings suggested that different part of feijoa (especially leaves and peel) could be used as a natural antibacterial and an-tioxidant for functional foods.


2019 ◽  
Vol 1 (2) ◽  
pp. 22-26
Author(s):  
Romauli Anna Teresia Marbun ◽  
Aminah Syarifuddin ◽  
Montysory Silalahi ◽  
Radika Bella Fista Ginting

Diseases mediated by the immune system are difficult problems to treat such as human immunodeficiency virus (HIV) and other lethal viruses. Infections that occur in normal people are generally brief and rarely leave permanent damage. Treatment of this disease requires an aggressive and innovative approach to the development of new treatments so that it requires the role of immunomodulators to improve the immune system. A substance that acts as an enhancer or immune enhancer can be obtained by using herbs that are efficacious as immunostimulants. One of the herbs used is herbal binara (Artemisia vulgaris L) which has been studied as a potential immunomodulator with high antioxidant activity. Previous research also stated that red shoots (Syzygium oleana) were studied as potential immunomodulators with high antioxidant activity. Several other species such as Syzygium samarangense have 16 flavonoida compounds which show pharmacological immunological activity. The purpose of this study was to determine the content of secondary metabolites of ethanol extract of herbal binara (Artemisia vulgaris L.) with red shoots (Syzygium oleana) and to determine the best dose of extract from the ethanol extract of herbal binara (Artemisia vulgaris L.) with red shoots (Syzygium oleana) can reduce the volume of swelling of mouse feet. Examination of the chemical content of secondary metabolites from the ethanol extract of herbal binara (Artemisia vulgaris L.) with red shoots (Syzygium oleana) is carried out by chemical screening and characterization of simplicia and extract. The method used is the slow type hypersensitivity method. In this test the independent variable is the secondary metabolite of ethanol extract of herb binara (Artemisia vulgaris L.) with red shoots (Syzygium oleana) with four concentrations (50, 100, 200 and 400 mg / kgBB). The positive control used by Stimuno dose is 32.5 mg / kgBB


2018 ◽  
Vol 69 (5) ◽  
pp. 1041-1044
Author(s):  
Claudia Anca Mot ◽  
Andreea I. Lupitu ◽  
Simona Bungau ◽  
Ciprian Iovan ◽  
Dana Maria Copolovici ◽  
...  

The aim of this study was to determine the phenolic content and antioxidant activity of extracts obtained from herb of Tanacetum vulgare L. (tansy) harvested in two different locations from the western part of Romania. Aqueous extracts of tansy presented high antioxidant activity that ranged between 295.77 and 653.65 mg GAE/L, and remarkable percentage of inhibition (31.82-65.05 %). The compounds quantified in the plant extracts that were determined by UHPLC are: ascorbic acid, riboflavin, pyrocatechol, rutin, quercetin, and kaempferol. Extracts obtained from tansy flowers showed higher content of phenols compared to that obtained from leaves. Similarly, the flower extracts present a high antioxidant activity that could suggest their use as natural additives in food preservation and also in pharmaceutical industry and veterinary medicine.


2020 ◽  
Author(s):  
Isabel Pereira ◽  
José Eduardo Pereira ◽  
Luís Maltez ◽  
Alexandra Rodrigues ◽  
Catarina Rodrigues ◽  
...  

Abstract The development of injectable bone substitutes (IBS) have obtained great importance in the bone regeneration field, as a strategy to reach hardly accessible defects using minimally invasive techniques and able to fit to irregular topographies. In this scenario, the association of injectable hydrogels and bone graft granules is emerging as a well-established trend. Particularly, in situ forming hydrogels have arisen as a new IBS generation. An in situ forming and injectable dextrin-based hydrogel (HG) was developed, aiming to act as a carrier of granular bone substitutes and bioactive agents. In this work, the HG was associated to a granular bone substitute (Bonelike®) and implanted in goat critical-sized calvarial defects (14 mm) for 3, 6 and 12 weeks. The results showed that HG improved the handling properties of the Bonelike® granules and did not affect its osteoconductive features, neither impairing the bone regeneration process. Human multipotent mesenchymal stromal cells from the umbilical cord, extracellular matrix hydrolysates and the pro-angiogenic peptide LLKKK18 were also combined with the IBS. These bioactive agents did not enhance the new bone formation significantly under the conditions tested, according to micro-computed tomography and histological analysis.


Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2888
Author(s):  
Carmen M. S. Ambrosio ◽  
Gloria L. Diaz-Arenas ◽  
Leidy P. A. Agudelo ◽  
Elena Stashenko ◽  
Carmen J. Contreras-Castillo ◽  
...  

Essential oils (EOs) from Citrus are the main by-product of Citrus-processing industries. In addition to food/beverage and cosmetic applications, citrus EOs could also potentially be used as an alternative to antibiotics in food-producing animals. A commercial citrus EO—Brazilian Orange Terpenes (BOT)—was fractionated by vacuum fractional distillation to separate BOT into various fractions: F1, F2, F3, and F4. Next, the chemical composition and biological activities of BOT and its fractions were characterized. Results showed the three first fractions had a high relative amount of limonene (≥10.86), even higher than the whole BOT. Conversely, F4 presented a larger relative amount of BOT’s minor compounds (carvone, cis-carveol, trans-carveol, cis-p-Mentha-2,8-dien-1-ol, and trans-p-Mentha-2,8-dien-1-ol) and a very low relative amount of limonene (0.08–0.13). Antibacterial activity results showed F4 was the only fraction exhibiting this activity, which was selective and higher activity on a pathogenic bacterium (E. coli) than on a beneficial bacterium (Lactobacillus sp.). However, F4 activity was lower than BOT. Similarly, F4 displayed the highest antioxidant activity among fractions (equivalent to BOT). These results indicated that probably those minor compounds that detected in F4 would be more involved in conferring the biological activities for this fraction and consequently for the whole BOT, instead of the major compound, limonene, playing this role exclusively.


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3741
Author(s):  
Wioleta Pietrzak ◽  
Renata Nowak

The content of plant secondary metabolites is not stable, and factors such as the region/location effect and seasonal variations have an impact on their chemical composition, especially in parasitic plants. Research in this area is an important step in the development of quality parameter standards of medicinal plants and their finished products. The effects of the time and place of harvest and the host tree species on the chemical composition and antioxidant activity of mistletoe extracts were investigated. Statistical tools were used to evaluate the results of the spectrophotometric and LC-ESI-MS/MS studies of the phenolic composition and antioxidant activity. The investigations indicate that the qualitative and quantitative composition, influencing the biological activity of mistletoe extracts, largely depends on the origin of the plant. The mistletoe extracts exhibited a rich phenol profile and high antioxidant activity. The chemometric analysis indicated that mistletoe collected from conifers (Viscum abietis and Viscum austriacum) had the most advantageous chemical composition and antioxidant activity. Moreover, the chemical profile and biological activity of the plant material were closely related to the climatic conditions and location of the harvested plant. Higher levels of phenolic compounds and high antioxidant activity were found in extracts obtained from plant material collected in cold weather with the presence of snow and less sunshine (autumn–winter period).


Author(s):  
FAVIAN BAYAS-MOREJON ◽  
ANGELICA TIGRE ◽  
RIVELINO RAMON ◽  
DANILO YANEZ

Objective: The increase in chronic and degenerative diseases and the use of synthetic antioxidants such as (butylated hydroxyanisole (BHA) or butylated hydroxytoluene (BHT)) are being restricted because they can be considered carcinogenic. Therefore, there is a growing interest in the search for natural antioxidants, especially from plants, due to their content in different bioactive compounds, such as antioxidants and antimicrobials. To evaluate the antibacterial and antioxidant activity of Baccharislatifolia extracts. Methods: For the determination of the antimicrobial activity of extracts of leaves, root, stem and flowers of Baccharislatifolia (Bl), the disk plate diffusion method was used, the strains of Listeria, Salmonella and E. coli were studied; antibiotics Penicillin G and Ciprofloxacin were the controls. For the antioxidant activity, a solution of H2O2 (Abs at 230 nm) was prepared in Potassium Phosphate Monobasic-Sodium Hydroxide buffer. Results: The antimicrobial activity against Listeria and Salmonella, showed that the extracts of leaves and flowers were more effective with inhibition zones>15 mm and>20 mm respectively. In front of E. coli, the extracts of flowers and stem were the best with zones>7.0 mm. Antibiotics studied inhibited the development of Listeria and Salmonella. However, E. coli isolates were resistant. In the antioxidant activity, the flower extract of Bl in 60 mg/ml presents a higher effect with 47.25%. Conclusion: Bl extracts from leaves and flowers were more efficient both in their antimicrobial and antioxidant capacity.


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