Decline In Antioxidant Activity Research Articles

Stability and Shelf‐Life Modeling of Lemongrass Essential Oil‐in‐Water Nanoemulsions

ABSTRACTThis study investigates the stability and shelf life of lemongrass essential oil‐in‐water (LGEO/W) nanoemulsions, a rich source of bioactive compounds (e.g., citral and citronellal) and a promising natural preservative. Initially, LGEO/W emulsions were produced through premix membrane emulsification (PME) and traditional methods such as high‐pressure homogenization (HPH) and ultrasonication (US) to generate micron‐ and nano‐sized emulsions. Subsequent investigations focused on assessing the stability of nanoemulsions under various storage temperatures, employing a range of physicochemical and antimicrobial tests. Results revealed that neither the emulsification technique nor emulsion droplet size (in the range of 0.1 to 10 µm) affected the antioxidative or antimicrobial properties of LGEO/W emulsions. Additionally, a combined approach of principal component analysis and traditional reaction kinetics was employed to examine the decline in antioxidative activity of PME‐generated nanoemulsions, to model the quality degradation kinetics over time under various storage temperatures. These findings offer valuable insights into the production, stability, and application of LGEO/W nanoemulsions, highlighting their potential as effective natural preservatives.

Activated Growth Factor From Platelets as Treatment for Diabetic Retinopathy Through Antioxidant-Oxidative Stress Pathway.

Reactive oxygen species (ROS) is known to play a significant role in the activation of chronic inflammatory processes in diabetic retinopathy. This study was aimed to evaluate activated growth factor (AGF) from platelet for diabetic retinopathy treatment, utilizing an in vivo investigation to regulate the antioxidant-oxidative stress pathway. The activated growth factor was initially derived by extracting intravenous blood from the rats. Advanced glycation end products (AGEs), p38 mitogen activated protein kinase (p38 MAPK), nuclear factor-κβ (NF-κβ), reactive oxygen species (ROS), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), superoxide dismutase (SOD) and vascular endothelial growth factor (VEGF) was assessed using enzyme linked immunoassay (ELISA). In vivo, diabetic retinopathy rat models were induced by streptozotocin injection and were evaluated by retinal funduscopy. The mean diameter of the retinal artery was significantly reduced when activated growth factor with transforming growth factor-β concentration of 10 ng/mL or 100 ng/mL was administered (p<0.05). The retinal tissue of diabetic rats showed a decline in antioxidant activity due to oxidative stress. AGF containing TGF-β (10 ng/mL and 100 ng/mL) significantly increased SOD activity (p<0.05). AGF administration effectively decreased proinflammatory cytokines like TNF-α and IL-1β. The study shows that AGF, with TGF-β concentrations of 10 ng/mL and 100 ng/mL, can reduce AGEs, p38MAPK, Nf-κβ, ROS, TNF-α, IL-1β, VCAM-1, ICAM-1, and VEGF in diabetic retinopathy rats' retinal tissue, while increasing antioxidant SOD concentration, suggesting AGF may help treat diabetic retinopathy by reducing inflammation and oxidative stress.

Effect of storage time on antioxidant content in seeds of agricultural plants

This study investigated the impact of storage time on the prooxidant-antioxidant balance (PAB) in seed tissues of 12 agricultural plant species, including both monocots and dicots. We measured superoxide generation, TBA-active products, and the activity of enzymatic antioxidants (superoxide dismutase, catalase, and cytochrome oxidase) and non-enzymatic antioxidants (ascorbic acid and glutathione). Biochemical parameters were recorded monthly for one year. Our results demonstrated that the activity of enzymatic antioxidants and the content of non-enzymatic antioxidants decreased with increased seed storage time. Conversely, both the generation of reactive oxygen species and the level of free radical damage to biomolecules increased. The percentage change in free radical peroxidation and antioxidant protection depended on the initial PAB status of the seeds. Monocots exhibited a greater overall increase in prooxidant activity during storage, while dicots showed a less pronounced decrease in antioxidant content. A notable surge in prooxidant activity and a corresponding decline in antioxidant activity occurred at 9-10 months of storage for dicots and 6-7 months for monocots. These findings highlight the importance of considering storage time and species-specific differences to optimize planting strategies and seed care, as well as the use of appropriate plant foods.

Additives improve the fermentation quality, anthocyanin content, and biological activity of purple Napier grass silage.

Purple Napier grass (PNG), a widely used grass rich in anthocyanin, is commonly employed in the production of silage. However, there is currently limited research on the retention of anthocyanin with or without additives during ensiling. Therefore, this study aimed to investigate the effect of different additives (Lactiplantibacillus plantarum CCZZ1 (LP), glucose, acetic acid, and dried soybean curd residue) on fermentation quality, anthocyanin content, and microbial community structure of PNG silage. Ensiling PNG without additives led to poor fermentation quality and rapid degradation of anthocyanin, resulting in a decline in antioxidant activity and the persistence of harmful microorganisms with high relative abundance. The use of additives, especially LP, effectively increased the relative abundance of L. plantarum, enhancing fermentation quality, the retention of anthocyanin (up to 166% increase rate) and antioxidant activity, while reducing the relative abundance of harmful microorganisms during ensiling for 30 days. Additionally, prolonged ensiling negatively affected the preservation of anthocyanin. Based on both fermentation quality and bioactivity, PNG should be ensiled for 30 days with LP inoculation. The employment of additives, especially LP, improved the fermentation quality, anthocyanin retention, and microbial community structure in PNG silage. To optimize both fermentation quality and bioactivity, it is recommended that PNG be ensiled for 30 days with LP inoculation. © 2024 Society of Chemical Industry.

Development of Spray Drying of Powdered Oolong Tea Incorporated with Chinese Jujube Beverage

One useful economic crop which is utilized worldwide is Chinese jujube. It offers both nutritional and therapeutic benefits. Meanwhile, Oolong tea is a semi-oxidized form of tea which has a flavour that falls somewhere between black tea and green tea. Finally, spray-drying is an important technique used in food preservation. This current study sought to assess the most suitable use of Chinese jujube along with appropriate levels of maltodextrin when creating a mixed Oolong tea which incorporates Chinese jujube and is subsequently processed via spray-drying. Oolong tea served as the control sample, while evaluations were carried out on 60%, 70% and 80% blends of Chinese jujube with maltodextrin which served as a carrier agent at concentrations of 20 g, 30 g, 40 g and 50 g. These solutions underwent spray-drying where the respective inlet and outlet temperatures were 190°C and 80°C. An evaluation of the physico chemical, microbiological and sensory evaluation were performed. There was evidence of an increase in the total phenolic compounds, whereas in contrast there was a decline in antioxidant activity. L* and +a* showed no statistically significant difference, although for +b* a statistically significant difference was found. For products with mixed Chinese jujube and Oolong tea, the moisture, water activity and pH values were shown to be lower, although there was an increase in total soluble solids. In the evaluation, flavour and overall acceptability for Treatment 4 (80% Chinese jujube) achieved the highest respective ratings at 8.17 and 8.13 on the 9-point scale. This demonstrates that spray-drying can be beneficial in the context of powdered particles. The combination of Chinese jujube and powdered Oolong tea provides good antioxidant properties and offers strong potential for applications in the food sector.

Impact of juice processing of Costa Rican guava (Psidum friedrichsthalianum) on the physicochemical properties, total phenols and antioxidant capacity

Psidium plants are commonly consumed in processed forms, leading to a need to evaluate the impact of processing on bioactive compounds. The purpose of this study is to assess the effect of Costa Rican guava juice processing on physicochemical and antioxidant characteristics. Five samples corresponding to distinct phases in the juice processing were evaluated. Total polyphenols were measured using the Folin-Ciocalteu method, while antioxidant activity was assessed using various methodologies, including chemical methods (DPPH and ORAC) and cell assays with kidney cell cultures, liver homogenates, and erythrocytes. Results revealed variations in the impact of the juice processing stages on total polyphenols and for each antioxidant assay, evidencing that different polyphenols counteract in each technique. Significant decreases (ranging from 27 % to 58 %, p < 0.05) were primarily observed during the pressing stage, while thermal treatments resulted in non-significant reductions. This study demonstrated a decline in antioxidant activity during the processing of Costa Rican guava juice underscoring the need for continued efforts to optimize processing conditions and enhance the retention of health-promoting properties in the juice.

Neuroprotective effects of g-Aminobutyric acid-enriched germinated riceberry extract in cerebral ischemic reperfusion-induced cognitive impairment mice

This study investigates the neuroprotective effects of riceberry (RB) and germinated riceberry (GRB) extracts on cognitive impairment induced by cerebral ischemia-reperfusion (IR) injury. Our findings indicate that the germination process reduces total phenolic content and total antioxidant capacity, accompanied by a decline in antioxidant activity. However, the enriched γ-aminobutyric acid (GABA) content significantly increased in the GRB extract, reaching an 11.55-fold higher concentration than the RB extract. Male ICR mice were used in this study and received RB (500 mg/kg BW) or GRB (250 and 500 mg/kg BW) extracts for 28 days, with cerebral IR injury induced on day 21. Memory and learning were assessed using the Morris water maze on days 22–27 and novel object recognition on day 28. Both RB and GRB extracts improved spatial and recognition memory while reducing hippocampal malondialdehyde levels, indicating decreased oxidative stress. GRB demonstrated superior effects, displaying accelerated learning responses and enhanced retention of spatial memory. The study highlights the potential of GRB, attributed to its high GABA content, in mitigating cognitive impairment induced by cerebral IR injury. Further research is needed to explore the underlying mechanisms and optimize therapeutic applications.

An overview: the effect of fermentation and roasting methods on cocoa quality

Cocoa is Indonesia’s most important commodity and one that can contribute to economic development but has a problem, which is the low quality of cocoa produced. Differences in cocoa type, roasting and fermentation affect the quality content of cocoa such as antioxidants, free fatty acid and the fat profile of cocoa. Of the different methods of cocoa bean processing that affect the changes in antioxidant compounds are fermentation and roasting. Fermentation is best with 6 days in producing the aroma flavor of cocoa precursors and bulk cocoa type with an optimal time of 5-7 and fine cocoa type with an optimal time of 3-4 days. Superheated steam method slows down the rate of decline in antioxidant content, this condition is different from the conventional roasting method commonly used because it removes a lot of cocoa antioxidant content and accelerates the decline in antioxidant activity. Non-fermentation treatment results in low free fatty acid values while fermentation treatment can increase free fatty acid content but can be controlled by the addition of alkalization. on the fat profile geographical location such as differences in country of origin affects the content of fatty acid composition but fermentation and roasting processes has no significant effect on the fatty acid composition of cocoa.

Application and stability of fungal pigments using jelly sweets as a food model system

SummaryNatural pigments have seen an increase in usage over the past decades due to their acclaimed safety and active biological properties. This is in line with the shift in consumer market preferences requiring a source replacement for synthetic colourants. Filamentous fungi are amongst the natural sources currently explored for pigment production. In this study, the heat, pH and UV light stability of fungal pigments produced by Penicillium multicolour (dark brown), P. canescens (green) and P. herquie (yellow). Talaromyces verruculosus (red) and Fusarium solani (orange) were evaluated. The antioxidant properties of the pigments as influenced by these conditions were ascertained using the 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) assay. The pigments were also applied in a jelly sweet formulation and incubated at ambient temperature for 4 weeks. It was demonstrated that the pigment extracts of P. multicolour and T. verruculosus were significantly affected by higher pH (7.0 and 9.0), where the decline in antioxidant activity was observed. As far as high temperature and UV light exposure are concerned, all the pigment extracts, with exception of P. herquie, maintained an antioxidant activity above 35%. On the other hand, the L*a*b* values showed no overall significant change for heat and UV light exposure with the exception of P. canescens across the four pH levels (3.0, 4.0, 7.0 and 9.0), where an increase in the ‐a (green index) coupled with a decline in brightness (L* index) and b* (blue index) was observed. Finally, there was no significant change in colour over the 4 weeks of incubation. In conclusion, fungal pigments are generally stable at normal storage conditions (ambient temperature and normal light) and can be suitably applied in jelly sweets.

Effects of Different Heating Treatments on the Antioxidant Activity and Phenolic Compounds of Ecuadorian Red Dacca Banana.

The banana is a tropical fruit characterized by its composition of healthy and nutritional compounds. This fruit is part of traditional Ecuadorian gastronomy, being consumed in a wide variety of ways. In this context, unripe Red Dacca banana samples and those submitted to different traditional Ecuadorian heating treatments (boiling, roasting, and baking) were evaluated to profile their phenolic content by ultra-high-performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS) and the antioxidant activity by ORAC, ABTS, and DPPH assays. A total of sixty-eight phenolic compounds were identified or tentatively identified in raw banana and treated samples, highlighting the content in flavonoids (flavan-3-ols with 88.33% and flavonols with 3.24%) followed by the hydroxybenzoic acid family (5.44%) in raw banana samples. The total phenolic compound content significantly decreased for all the elaborations evaluated, specifically from 442.12 mg/100 g DW in fresh bananas to 338.60 mg/100 g DW in boiled (23.41%), 243.63 mg/100 g DW in roasted (44.90%), and 109.85 mg/100 g DW in baked samples (75.15%). Flavan-3-ols and flavonols were the phenolic groups most affected by the heating treatments, while flavanones and hydroxybenzoic acids showed higher stability against the heating treatments, especially the boiled and roasted samples. In general, the decrease in phenolic compounds corresponded with a decline in antioxidant activity, evaluated by different methods, especially in baked samples. The results obtained from PCA studies confirmed that the impact of heating on the composition of some phenolic compounds was different depending on the technique used. In general, the heating processes applied to the banana samples induced phytochemical modifications. Even so, they remain an important source of bioactive compounds for consumers.

Studies on triazophos-induced oxidative stress and genotoxicity in freshwater fish Cyprinus Carpio following sublethal exposures

Triazophos (TAP), an organophosphorus insecticide, is widely used in agricultural practice for controlling various insect pests. The present research work aimed to elucidate the impact of TAP on the antioxidant status and DNA content of the freshwater fish Cyprinus carpio. The fish were grouped into batches (n=6) and received a sublethal dose of 0.3mg/L for a duration of 1 (E1), 10 (E2), 20 (E3) and 30 days (E4). Another group, devoid of any toxicant, was maintained as the control (C). Changes in the enzymatic threshold of the selected antioxidants and malondialdehyde (MDA) levels suggested the conformation of oxidative stress in the livers of the freshwater fish C. carpio due to TAP exposure. Additionally, comet assays and micronucleus tests performed on the peripheral blood of the fish suggested increased damage in the form of the percentage of tail DNA formation and a high frequency of micronucleus as compared to the control. A positive correlation was seen between the decline in antioxidant activity, the elevation in MDA and the comet length and micronucleus frequency. The study thus highlights the impact of TAP on antioxidant levels in the livers and genotoxicity in the blood of the freshwater fish C. carpio. The findings of the study confirm that the antioxidant status, along with the comet assay and micronucleus tests could be used as tools in determining the potential genotoxicity due to the TAP impact. It is therefore suggested that extensive use of TAP should be avoided as it may contribute to the decline in the C. carpio population in its natural habitats.

Antibacterial and Antioxidant Activity of Ecoenzyme Solution Prepared from Papaya, Pineapple, and Kasturi Orange Fruits: Experimental and Molecular Docking Studies

Organic waste, particularly from fruits, remains an environmental issue if not properly managed. These wastes have the potential to be reprocessed into products, one of which is beneficial for human health. The trend of recycling fruit scraps into ecoenzyme (EE), a fermented product, has increased in recent years. Several health advantages of EE have been highlighted. Therefore, this study is aimed at evaluating the potential antibacterial and antioxidant activity of ecoenzyme solutions derived from papaya, pineapple, and Kasturi orange. In this study, pieces of papaya, pineapple, and Kasturi orange were fermented with brown sugar for 10 days and 3 months. The 10-day- and 3-month-old fermented solutions were used as samples to evaluate their inhibitory abilities against the growth of Escherichia coli and Staphylococcus aureus using the well diffusion method. In addition, the fermentation solutions were tested for their antioxidant capacity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Furthermore, a molecular docking study was conducted to evaluate the compounds found in these three fruits for their ability to interact with the DNA gyrase of the two indicator bacteria. The enzyme, which is a well-established antimicrobial target, is involved in bacterial DNA replication, repair, and decatenation. The in vitro results revealed that EE, both fermented for 10 days and 3 months, had strong inhibition against E. coli and S. aureus. The 3-month-old fermentation solution showed stronger inhibitory activity than the 10-day-old fermentation solution. Despite a slight decline in antioxidant activity with increasing fermentation time, both of these samples exhibited extremely potent antioxidant activities. Molecular docking studies revealed that hesperidin and ciprofloxacin interacted more strongly with the DNA gyrase of S. aureus than with E. coli. Hesperidin can therefore function as a potent antimicrobial. The present study concluded that EE solution fermented from papaya, pineapple, and Kasturi orange exhibits the potential to serve as a source of both antibacterial and antioxidant compounds.

Antioxidant Activity of Frozen and Freeze-Dried Drone Brood Homogenate Regarding the Stage of Larval Development.

Drone brood is a little-known and poorly studied bee product used and valued in the treatment of many diseases, including male infertility and women’s menopausal disorders. The aim of this study was to evaluate the antioxidant activity of drone brood depending on the stage of larval development and the method of preservation. Aqueous and ethanolic homogenate extracts of drone brood were assayed for antioxidant activity (with the DPPH, FRAP, and ABTS methods), polyphenol, and flavonoid content. The extracts’ polyphenolic profiles were compared by the HPTLC method. Drone brood has been shown to be more active in the earlier stages of development (between days 7–11), with a decline in antioxidant activity in the later period (by the 14th day). The freeze-drying process did not cause significant changes in the antioxidant activity of brood preparations converted to dry mass. Based on the higher activity of the aqueous compared to 70% ethanolic extracts, it was shown that the dominant fraction of brood consisted of hydrophilic antioxidants. The results obtained with different methods were highly correlated, excluding those from the ABTS assay. The HPTLC method showed that the polyphenol fraction of drone brood homogenate consisted mainly of phenolic acids and flavonoids. It was shown that drone brood has valuable antioxidant properties that can be compared with royal jelly.

Relationships between Structure and Antioxidant Capacity and Activity of Glycosylated Flavonols.

The antioxidant capacity (AC) and antioxidant activity (AA) of three flavonols (FLV), aglycones and their glycosylated derivatives were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays in various solvents. Findings confirmed that the glycosylation at the 3-position (3-glycosylation) always decreased the AC under most conditions due to substitution of the 3-position hydroxyl group and glycoside disruption in the molecular planarity. The 7-glycosylated derivatives did not have the above effects, thus generally exhibited ACs similar to their aglycones. Glycosylation decreased the AA of kaempferol and isorhamnetin for both assays in methanol, 3-glycosylation inhibited quercetin AA in the ABTS assay. In the DPPH assay, the AA of 3-glycosylated quercetin was significantly higher than quercetin. Using LC–MS/MS analysis, we found that quercetin and quercetin-7-glucoside underwent dimerization during the antioxidant reaction, potentially leading to a decline in AAs. However, 3-glycoside substitution may have hindered dimer formation, thereby allowing the FLVs to retain strong free radical scavenging abilities.

Passiflora edulis(var. Flavicarpa)Juice Supplementation Mitigates Isoproterenol-induced Myocardial Infarction in Rats.

The common reason for mortality globally is myocardial infarction. The study aimed to evaluate Passiflora edulis (PE) fruit juice potential in the experimental isoproterenol (ISO) treated rat model to manage myocardial injury. ISO (20mg/100g body weight) treated rats showed a significant increment in serum marker enzymes lactate dehydrogenase (LDH) and creatinine kinase (CK), serum glutamate pyruvate transaminase (SGPT), serum glutamate oxaloacetate transaminase (SGOT), serum alkaline phosphatase (ALP) and serum acid phosphatase (ACP) activity. Besides, phosphorus and calcium, serum cholesterol, and triglyceride levels (TG) were high in ISO groups. A significant decline in antioxidant activity and histopathological alteration was observed in ISO treated groups. PE juice pre-treatment (2 ml/kg) for 28 days and ISO treatment on the 29th and 30th days showed a protective effect on distorted biochemical and histopathologic parameters compared with reference drug metoprolol. These findings indicate the cardioprotective effect of PE juice on ISO-induced myocardial infracted rats.

Green synthesis of silver nanoparticles usingTropaeolum majus: Phytochemical screening and antibacterial studies

AbstractThe green biosynthesis of metal nanoparticles of already explored phytomedicines has many advantages such as enhanced biological action, increased bioavailability, etc. In this direction, keeping in view the peculiar medicinal value ofTropaeolum majusL., we synthesized its silver nanoparticles (AgNPs) by adopting eco-friendly and cost-effective protocol by using methanolic and aqueous extract ofT. majus. The synthesized AgNPs were characterized by using several techniques including UV spectroscopic analysis, FTIR analysis, and atomic force microscopy. The methanolic/aqueous extracts ofT. majusand synthesized AgNPs were assessed for antioxidant potential and antimicrobial effect. The preliminary screening showed that theT. majusextracts have variety of reducing phytochemicals including tannins, terpenoids, flavonoids, and cardiac glycosides. The green synthesis of AgNPs was confirmed by the appearance of sharp peak at 430–450 nm in the UV-Visible spectra. The FTIR spectral analysis of extract and AgNPs exhibited that peaks at 2947.23, 2831.50, 2592.33, 2522.89, and 1,411 cm−1disappeared in the spectra of FTIR spectra of the AgNPs, indicating carboxyl and hydroxyl groups are mainly accountable for reduction and stabilization of AgNPs. Atomic force microscopic scan of the synthesized AgNPs confirmed its cylindrical shape with size of 25 µm. The extracts and AgNPs were investigated for antioxidant potential by DPPH-free radical essay, which showed that aqueous extract has significant and dose-independent antioxidant activity; however, the synthesized AgNPs showed decline in antioxidant activity. The extracts and synthesized AgNPs were also evaluated for antibacterial activity againstKlebsiella pneumonia,Staphylococcus aureus, andBacillus subtilis.Neither extract nor AgNPs were active againstKlebsiella pneumonia.The aqueous and methanolic extract exhibited inhibition againstBacillus subtilisand their synthesized AgNPs were active againstStaphylococcus aureus.Our data concluded that the extracts ofT. majushave necessary capping and reducing agents which make it capable to develop stable AgNPs. The aqueous extract ofT. majushas potential antioxidant effect; however, the AgNPs did not enhance its free radical scavenging effect. The bacterial strains’ susceptibility of the extract and AgNPs was changed fromBacillus subtilistoStaphylococcus aureus, respectively. The biological action of AgNPs is changed in case of antibacterial activity which means that AgNPs might change the specificity ofT. majusand likewise other drugs.

Extraction and Determination of Antioxidant Activity of Vietnamese Butterfly Pea (&lt;i&gt;Clitoria ternatia&lt;/i&gt; L.)

The objective of this study was to determine the optimal value of factors affecting the antioxidant activity extraction of antioxidant activity of butterfly pea flowers. The investigated factors included extraction temperatures (30, 40, 50, 60, 70 and 80°C), extraction time (30, 60, 90, 120 and 150 minutes) and solid to solvent ratio (1:05, 1:10, 1:20, 1:40 and 1:50 g/mL). The efficiency of extraction was evaluated based on antioxidant activities which were measured by DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging assay and ferric reducing antioxidant power assay (FRAP). The results showed that when the extraction process was performed at temperatures of 60°C, the resulting extracts with highest DPPH antioxidant activity (575.10 μmolTE/L) and FRAP (1093.83 μmolTE/L) was obtained. Considering the effect of extraction time on antioxidant activities of butterfly pea, time range of 30–90 minutes led to highest DPPH values while extracts with highest FRAP power were collected after 120 minutes. Moreover, decreasing solid-to-solvent ratio resulted in the decline in antioxidant activities.

Mitochondria-targeted antioxidant SKQ1 protects cornea from oxidative damage induced by ultraviolet irradiation and mechanical injury

BackgroundCornea protects the eye against natural and anthropogenic ultraviolet (UV) damage and mechanical injury. Corneal incisions produced by UV lasers in ophthalmic surgeries are often complicated by oxidative stress and inflammation, which delay wound healing and result in vision deterioration. This study trialed a novel approach to prevention and treatment of iatrogenic corneal injuries using SkQ1, a mitochondria-targeted antioxidant approved for therapy of polyethiological dry eye disease.MethodsRabbit models of UV-induced and mechanical corneal damage were employed. The animals were premedicated or treated with conjunctival instillations of 7.5 μM SkQ1. Corneal damage was assessed by fluorescein staining and histological analysis. Oxidative stress in cornea was monitored by measuring malondialdehyde (MDA) using thiobarbituric acid assay. Total antioxidant activity (AOA) was determined using hemoglobin/H2O2/luminol assay. Glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities were measured using colorimetric assays.ResultsIn both models corneas exhibited fluorescein-stained lesions, histologically manifesting as basal membrane denudation, apoptosis of keratocytes, and stromal edema, which were accompanied by oxidative stress as indicated by increase in lipid peroxidation and decline in AOA. The UV-induced lesions were more severe and long healing as corneal endothelium was involved and GPx and SOD were downregulated. The treatment inhibited loss of keratocytes and other cells, facilitated re-epithelialization and stromal remodeling, and reduced inflammatory infiltrations and edema thereby accelerating corneal healing approximately 2-fold. Meanwhile the premedication almost completely prevented development of UV-induced lesions. Both therapies reduced oxidative stress, but only premedication inhibited downregulation of the innate antioxidant activity of the cornea.ConclusionsSkQ1 efficiently prevents UV-induced corneal damage and enhances corneal wound healing after UV and mechanical impacts common to ocular surgery. Its therapeutic action can be attributed to suppression of mitochondrial oxidative stress, which in the first case embraces all corneal cells including epitheliocytes, while in the second case affects residual endothelial cells and stromal keratocytes actively working in wound healing. We suggest SkQ1 premedication to be used in ocular surgery for preventing iatrogenic complications in the cornea.

Antioxidant capacity and fatty acids characterization of heat treated cow and buffalo milk

BackgroundAntioxidant capacity of milk is largely due to vitamins A, E, carotenoids, zinc, selenium, superoxide dismutase, catalase, glutathione peroxidase and enzyme systems. Cow milk has antioxidant capacity while the antioxidant capacity of buffalo milk has been studied in a limited way. The information regarding the effect of pasteurization and boiling on antioxidant capacity of cow and buffalo milk is also scared.MethodsCow and buffalo milk was exposed to two different heat treatments i.e. 65 °C for 30 min and boiling for 1 min. After heat treatments, milk samples were cooled down to 4 °C packaged in transparent 250 ml polyethylene PET bottles and stored at 4 °C for 6 days. Milk composition, total flavonoid content, total antioxidant capacity, reducing power, DPPH free radical scavenging activity, antioxidant activity in linoleic acid, vitamin C, A, E, selenium, Zinc, fatty acid profile, peroxide value and sensory characteristics were studied in raw, pasteurized and boiled cow and buffalo milk at 0, 3 and 6 days of storage period.ResultsTotal antioxidant capacity (TAC) of raw, pasteurized and boiled milk for cow (42.1, 41.3 and 40.7%) and buffalo (58.4, 57.6 and 56.5%) samples was found, respectively. Reducing power (RP) of raw cow and buffalo milk was 6.74 and 13.7 while pasteurization and boiling did not showed significant effect on RP of both cow and buffalo milk. DPPH activity of raw, pasteurized and boiled milk for cow (24.3, 23.8 and 23.6%) and buffalo (31.8, 31.5 and 30.4%) samples was noted, respectively. Storage period up to 3 days was non-significant while DPPH assay after 6 days of storage period indicated significant decline in antioxidant activity of milk samples. Antioxidant activity in linoleic acid (AALA) of buffalo and cow milk were recorded 11.7 and 17.4%, respectively. Pasteurization and boiling did not showed any impact on antioxidant capacity of cow and buffalo milk. The Loss of vitamin C in pasteurization (40 and 42%) and boiling (82 and 61%) of cow and buffalo milk was recorded, respectively. Concentration of vitamin A and E in pasteurized cow and buffalo milk was not significantly different from raw milk samples of cow and buffalo. Concentration of selenium and zinc was not influenced by the heat treatment in both cow and buffalo milk samples. After 3 days of refrigerated storage, antioxidant capacity of both cow and buffalo milk decreased. Concentrations of short-chain and medium-chain fatty acids increased in pasteurized and boiled cow and buffalo milk, while long-chain fatty acids decreased in pasteurized and boiled cow and buffalo milk, with no effect on colour and flavor score. Peroxide value of pasteurized and boiled cow and buffalo milk was not influenced by the storage up to 3 days.ConclusionsThese results suggest that buffalo milk had a higher antioxidant capacity than cow milk and pasteurized milk should be consumed within 3 days of refrigerated storage for better antioxidant perspectives.

Evaluation of the potential use of probiotic strain Lactobacillus plantarum 299v in lactic fermentation of button mushroom fruiting bodies.

The available literature does not provide data on the application of probiotic strains in mushroom processing. The aim of the study was to evaluate the potential to use the L. plantarum 299v strain with documented probiotic properties in the process of lactic fermentation of button mushroom fruiting bodies (Agaricus bisporus). Fresh button mushroom fruiting bodies and cultures of lactic acid bacteria L. plantarum Ib and a probiotic strain L. plantarum 299v were the material analysed. Sensory evaluation was performed with a 5-point scale, an instrumental method of colour measurement based on the CIA L*a*b* scale, total phenolic compounds were determined with the Folin method, antioxidant properties were assayed with the DPPH radical test, and reducing power was determined using the FRAP method. After a week-long lactic fermentation, the pH value in the samples declined to a level of 3.6 (L. plantarum Ib) and 3.75 (L. plantarum 299v); these values persisted or decreased slightly during the period of maturation of the fermented samples under refrigeration. Fermented mushrooms were assigned high grades in the organoleptic evaluation. The colour analysis revealed significant changes in the values of the L*a*b* parameters in the fermented product, in comparison with fresh mushrooms. Blanching contributed to a significant decrease in the content of total phenolic compounds in the mushroom fruiting bodies and to a decline in antioxidant activity. Mushrooms fermented with the probiotic strain were characterised by higher phenolic compound content and higher antioxidant activity. L. plantarum 299v strain with documented probiotic properties can be applied in fermentation of button mushroom fruiting bodies. Products obtained with the use of both strains were characterised by good sensory properties. The type of strain used in the lactic fermentation of mushroom fruiting bodies had an effect on the phenolic compound content and antioxidant properties of the final product.