Synergistic Antioxidant Activity Research Articles

Synergistic Antioxidant Activity of Lycium barbarum Polysaccharide and Chlorogenic Acid and Its Effect on Inflammatory Response of NR8383 Cells.

It is inevitable for polyphenols and polysaccharides to interact during food preparation. Modifications in microstructure can lead to changes in the physical and chemical properties of food systems, which in turn may influence the nutritional characteristics and functional activities of the food. Recent studies have shown that, in addition to traditional Chinese medicine compounds, certain natural polysaccharides and polyphenols exhibit significant anti-inflammatory and antioxidant properties. These compounds are also associated with beneficial therapeutic effects for the prevention and treatment of acute lung injury. The objective of this study was to examine the synergistic antioxidant effects of chlorogenic acid (CA) and Lycium barbarum polysaccharide (LBP) in various ratios, along with their combined antioxidant and anti-inflammatory effects on LPS-induced inflammation in rat alveolar macrophages. Using the Combination Index (CI), which quantifies the synergistic or antagonistic effect of two substances, all four combinations showed synergistic antioxidant properties over a range of concentrations by in vitro antioxidant property experiments. However, based on comparing them, the four group ratios exhibited the highest antioxidant activity of the infusion at CA:LBP = 1:7, indicating synergistic interactions (CI < 1). In addition, the antioxidant and anti-inflammatory effects of the CA-LBP complex were observed to alleviate cellular inflammatory injury by reducing LPS-induced nitric oxide and reactive oxygen species production and inhibiting the release of inflammatory factors such as TNF-α and IL-6.

Synergistic Antioxidant Activity in Deep Eutectic Solvents: Extracting and Enhancing Natural Products

Synergistic Antioxidant Activity in Deep Eutectic Solvents: Extracting and Enhancing Natural Products

Phytochemical composition, antioxidant activities and anti‐obesity potential of selected vegetables as affected by drying methods

AbstractObesity has reached epidemic statistics worldwide and there is an urgent need to explore more available options in addressing the condition. The potential of vegetables as natural sources of enzyme inhibitors that can regulate the progression of obesity is of great interest particularly due to possible synergistic antioxidant activities. In this study, we evaluated the phytochemical composition, antioxidant activities, and in vitro enzyme inhibition properties of selected vegetables as influenced by sun and cabinet drying methods. While a significant increase was observed in the phytochemical composition of most of the vegetables, the two drying methods had varying effects on all parameters. Cabinet drying yielded higher saponin (2.86–4.67 mg/100 g), phenolics (19.30–57.02 mg/100 g), and alkaloids (31.58–37.61 mg/100 g) contents while sun drying gave better results for flavonoids (88.13–234.15 mg/100 g). The DPPH (11.45%–29.61%) and ABTS (22.70%–35.48%) antioxidant activities varied significantly. Cabinet‐dried cabbage and sun dried carrot flours displayed the highest inhibition against alpha amylase and pancreatic lipase, respectively. A strong positive correlation was observed between phenolics and amylase inhibition and also between saponin and pancreatic lipase inhibition. Consequently, vegetable flours could serve as versatile products for the therapeutic management of obesity and related diseases.

Evaluation of Synergistic Antioxidant Activity of Psidium Guajava and Raw Honey- An Invitro study

Evaluation of Synergistic Antioxidant Activity of Psidium Guajava and Raw Honey- An Invitro study

Industrial Production of Bioactive Nutrient-Enhanced Extra Virgin Olive Oil under Continuous-Flow Ultrasound and Pulsed Electric Field Treatment.

Extra virgin olive oil (EVOO) is a cornerstone of the Mediterranean diet. Many studies have highlighted its crucial preventive role against cardiovascular disease, neurodegenerative disorders, metabolic syndrome and cancer, with these effects being due to the synergistic anti-inflammatory and antioxidant activities of minor components, such as polyphenols and tocols. The aim of the present study is to implement new technologies for olive oil mills and develop an efficient large-sized industrial process for the continuous extraction of healthier EVOOs that are enriched with these bioactive compounds. Non-thermal technologies, namely ultrasound (US) and pulsed electric field (PEF), have been tested, separately and in combination, to eliminate the need for traditional malaxation. There is extensive literature to support the efficacy of ultrasound-assisted extraction (UAE) and PEF treatments in EVOO production. A newly designed US device and a PEF industrial chamber have been combined into a single, integrated continuous-flow setup, the performance of which in the extraction of EVOO from green Coratina olives has been evaluated herein. Extraction yields, physico-chemical and organoleptic characteristics, and polyphenol and tocol contents were monitored throughout the trials, and the last three were measured at accelerated aging times (AAT) of 15 and 30 days. The US and combined US-PEF processes not only increased daily oil production (ton/day, by nearly 45%), but also eliminated the need for kneading during malaxation, resulting in significant energy savings (approximately 35%). In addition, these innovations enriched the resulting EVOO with nutritionally relevant minor components (8-12% polyphenols, 3-5% tocols), thereby elevating its quality and market value, as well as overall stability. The introduction of continuous-flow US and PEF technologies is a remarkable innovation for the EVOO industry, as they offer benefits to both producers and consumers. The EVOO resulting from non-thermal continuous-flow production meets the growing demand for healthier, nutrient-enriched products.

Exploring the wound healing activity of phytosomal gel of Annona squamosa and Cinnamomum tamala leaves ethanolic extracts with antioxidant and antimicrobial activities in S aureus infected excision wound model

Wound healing is a natural process but it is impaired in certain conditions like age, stress, health, immunity status and microbial infection. Particularly in cases of chronic wounds, infection is nearly often the main and unavoidable obstacle to wound healing. For this purpose, leaves of Annona squamosa and Cinnamomum tamala were selected based on their ethnopharmacological uses and reported pharmacological activities. The ethanolic extracts of both plant parts i.e. ethanolic extracts of Annona squamosa (ASEE) and Cinnamomum tamala (CTEE) were evaluated for their antioxidant and antimicrobial activities individually as well as in 1:1 combination as Polyherbal Ethanolic extract (PHEE). In our previous work both these ethanolic extracts were combined and phytosomes were prepared by thin layer hydration method and optimized for vesicle size and entrapment efficiency. The phytosomes were then incorporated into Carbopol gel matrix. In this present study the selected phytosomal gel was tested in two different concentrations (2% and 5%) for in vivo wound healing activity using S. aureus infected excision wound model. The various parameters examined were percentage wound contraction, epithelization period, bacteriological quantification, biochemical parameters like Superoxide dismutase (SOD), Catalase and hydroxyproline. The PHEE exhibited synergistic antioxidant activity. The PHEE also showed enhanced antimicrobial activity against bacteria namely gram-positive S. aureus, gram-negative E. Coli. The phytosomal gel showed increased wound contraction, reduced time of epithelization, increased hydroxyproline content, increased levels of SOD and Catalase enzymes and reduced bacterial load when compared with Povidone iodine ointment as standard in S. aureus infected excision wound model.

Synergistic antioxidant and antibacterial activities of polyphenol extracts from mangosteen peels in preservation of Pangasius hypophthalmus fish balls

In recent years, natural preservatives have attracted more and more attention in food processing since they can enhance food shelf-life and safety. In this study, the polyphenol extract was obtained from mangosteen peels using enzyme-microwave assisted method, characterized for its antioxidant and antimicrobial activities and subsequently used as a natural additive in fish ball preservation. Results revealed that the mangosteen peel polyphenol powder (MPP) had a high phenolic content of 154 mg gallic acid equivalent/g dry matter, which led to high 2,2-diphenyl-1-picrylhydrazyl free radical scavenging capacity of 95 mg Trolox equivalent/g dry matter. MPP also exhibited effective antimicrobial activity against E. coli and S. aureus, expressed by its large inhibitory zones (11.3 and 12.1 mm, respectively) and small ratios (less than 4) of minimum bactericidal concentration over minimum inhibitory concentration against tested bacteria. The MPP supplementation at the levels of 38 mg/100 g and 53 mg/100 g into fish balls remarkably improved their gel strength, reduced lipid oxidation, limited protein oxidation and structural degradation as compared to those of the control without any addition or with synthetic preservatives. Especially, the addition of 53 mg MPP/100 g could sufficiently retard the microorganism growth. The synergistic effects of MPP in both antioxidant and antimicrobial activities hence could extend the shelf-life of fish balls, more than 40 %, as compared to butylated hydroxytoluene (synthetic antioxidant) or sodium benzoate (synthetic antimicrobial) with their single effects. These findings imply that MPP could be potentially used as a natural additive in preservation of fish and meat products.

Proximate analysis, total phenolic content, acute toxicity, anti-oxidative and anti-inflammatory studies of Vigna unguiculata and Citrus limon using Wister rat models

Herbal medicines have been in use for thousands of years. It is estimated that 80% of world population rely on traditional herbal medicine for prophylaxis and therapy of different ailments. In recent years, there has been an upsurge in the use of these herbal remedies due to their cultural acceptability, availability, affordability, efficacy and safety claims. This study carried out the proximate analysis, total phenolic and Citric acid contents, acute toxicity, anti-oxidative and anti-inflammatory studies of Vigna unguiculata and Citrus limon using Wister rat models. Wister rats (135 – 140 g) were used for this study. Vigna unguiculata was extracted using ethanol for 72 hours. Proximate analysis, Citric acid content of Citrus limon, total phenolic content, acute toxicities, anti-oxidative and anti-inflammatory studies were done. The yield of the extract was 1.9%. The LD50 was greater than 5,000 mg/kg body weight. The Citric acid content of Citrus limon was 54.2 + 0.003 mg/ml. The proximate analysis showed the presence of protein, fat, carbohydrate, dietary fibre, moisture, and iron while total phenolic contents of Vigna unguiculata and Citrus limon were 15.3 and 19.3 mgGAE/L respectively. The combination of Vigna unguiculata and Citrus limon exhibited greatest anti-oxidation effect and recorded malondialdehyde concentration of 3.66 ± 0.34 nmol/ml as compared to the individual herbs that recorded 6.14 ± 0.38 and 4.28 ± 0.12 nmol/ml respectively. In anti-inflammatory assay, Vigna unguiculata had the best percentage inhibition of heat induced hemolysis of 62.79%. In conclusion, Vigna unguiculata and Citrus limon had synergistic antioxidant and antagonistic anti-inflammatory activities.

L‐ascorbyl palmitate and endogenous micronutrients in vegetable oils provide synergistic antioxidant activities: Micronutrient species and concentration

AbstractIn the present study, antioxidant impacts of L‐ascorbyl palmitate (L‐AP) on 14 kinds of typical vegetable oils were studied, whose ratios of C18:1 to C18:2 ranged from 0.15 to 9.57. Regression analyses between vegetable oils and their micronutrient‐free counterparts revealed that the antioxidant capacity of L‐AP was closely related to concentrations of α‐, γ‐, and δ‐tocopherols instead of fatty acid compositions. Binary mixtures consisting of L‐AP and α‐, γ‐, or δ‐tocopherols exhibited desirable synergistic antioxidant effects in comparison with individual species. The optimal synergistic effects were found at ratios of L‐AP to α‐, γ‐, δ‐tocopherols, being 1:2–1:4. Further EPR spin trapping test figured out that the combined antioxidants reduced the total amount of spin adducts significantly during lipid oxidation, which were contributed by regenerating tocopherols from L‐AP. The results will highlight the application of L‐AP in protecting packed cooking oils after opening and during cooking.Practical applications: Vegetable oils packaged in 4–5 L bottles are one of the most important forms for home cooking. Although deoxygenation techniques are applied to increase their shelf life during storage, they will experience a more violent oxidation reaction after opening. The oils are typically oxidized to rancidity before ending up in consumption. L‐AP was therefore involved into the vegetable oils to prevent them from oxidation during uses. The results of study can help companies to select the optimal L‐AP addition amount according to different endogenous tocopherol types and contents in the target oil in order to extend the use life of the vegetable oil.

Formulation Development of Directly Compressible Tablets Incorporating Trisamo Extract With Synergistic Antioxidant Activity.

This work investigates the synergistic antioxidant activity of the compositions of Trisamo (TSM) herbal formula containing the dried fruits of Terminalia chebula, Terminalia arjuna, and Terminalia bellirica. An augmented simplex lattice design was utilized to investigate the synergistic antioxidant activity, finding an equal mass ratio among the three herbal drugs to exhibit optimal synergistic antioxidant activity, with a combination index of less than 0.8. The optimal TSM extract was used to prepare directly compressible tablets employing a Box-Behnken design response surface methodology, optimizing compressional force (500, 1000, and 1500 psi), sodium starch glycolate (0%, 2%, and 4%), and magnesium stearate (0.5%, 1.0%, and 1.5%). Optimal parameters were a compressional force of 1000 psi, 2% sodium starch glycolate, and 0.5% magnesium stearate. The TSM extract tablet had a weight of 600.06 mg, a diameter of 12.78 mm, a thickness of 4.12 mm, a hardness of 6.85 kP, a friability of 0.30%, and a disintegration time of 1.81 min. Computer model predictions were verified with a low percentage error (≤ 10.00%). After 6 h, phenolic compounds were dissolved to an extent of approximately 40%-80%, including gallic acid (57.11%), corilagin (38.64%), chebulagic acid (58.49%), and chebulinic acid (81.44%). Stability data revealed that the phenolic compounds were retained for 3 months compared to the initial time point, with gallic acid at 81.43% and 100.27%, corilagin at 94.81% and 87.85%, chebulagic acid at 92.22% and 69.83%, and chebulinic acid at 107.00% and 85.54% at 30°C/75% RH and 45°C/75% RH, respectively. The summation of these four compounds did not change significantly when stored under either set of conditions. In summary, mixture design and response surface design were successfully utilized in the optimization of TSM extract tablets with synergistic antioxidant activity.

Toxicological Evaluation of a Polyherbal Formulation (18KHT01) and Validation of UPLC-DAD Method for Quality Control.

Background: 18KHT01 is a novel synergistic composition of Quercus acutissima, Camellia sinensis, Geranium thunbergii, and a small portion of Citrus limon. Our previous report demonstrated that the 18KHT01 exhibits potent antiobesity effects, with synergistic antioxidant, antiadipogenic, and antiobesity activities in diet-induced obese mice. This study explores the toxicity profile and quality control parameters of the 18KHT01 formulation. Methods: Broad-spectrum acute and subacute oral toxicity studies were performed using male and female ICR mice. In order to simultaneous analysis of the 18KHT01 formulation, an ultraperformance liquid chromatography coupled with a diode array detector (UPLC-DAD) method was developed and validated using six marker compounds. Results: Acute oral toxicity evaluation of 18KHT01, administered at single high doses of 2, 2.5, 3, and 5 g/kg, identified 2 g/kg as the no-observed adverse effect level (NOAEL). The LD50 (50% lethal dose) and LD100 (100% lethal dose) of 18KHT01 for male ICR mice were 3.99 and 7.77 g/kg, and those for the female mice were 2.94 and 4.70 g/kg, respectively. In addition, a 30-day repeated dose oral subacute toxicity evaluation indicated that 18KHT01 is safe below 500 mg/kg/day for long-term administration in ICR mice of either sex. UPLC-DAD method validation revealed that each calibration curve for the marker compounds showed good linearity, as well as the validation parameters such as precision, specificity, and accuracy met the acceptance criteria. Conclusion: The present study evidenced the toxicological profile of 18KHT01 polyherbal formulation in mice as well as developed a simple, rapid, and accurate chromatographic method for quality control.

Synergistic antioxidant and antibacterial effects of a Zn-ascorbate metal-organic framework loaded with marjoram essential oil.

Antimicrobial resistance (AMR) has become an immense threat to public health leading to an urgent need for development of new technologies to tackle such a challenge. Plant-based drugs, specifically essential oils (EOs) and plant extracts, have shown significant potential as effective green antimicrobial agents. However, they suffer from high volatility and low thermal stability resulting in their inefficient utilization in commercial settings. Among the various nanoencapsulation technologies reported, metal-organic frameworks (MOFs) have been recently investigated as potential nanocarriers of EOs in attempt to enhance their stability. Herein, we report the utilization of Zn-ascorbate MOF for the encapsulation of marjoram essential oil (MEO) with synergistic antioxidant and antibacterial activities. The prepared composite was thoroughly characterized via a number of techniques and its antibacterial performance was investigated against various strains of Gram-negative and Gram-positive bacteria. The results demonstrated that the antioxidant activity originated from the ascorbic acid ligand (l-Asc), while the antibacterial activity originated from Zn2+ ions as well as encapsulated MEO.

Application of steam explosion for preparing high value-added antioxidants from eggshell membrane waste

Eggshell membrane (ESM) is primary considered as food industry discard due to its highly insoluble structure. In this study, steam explosion was exploited to improve the utilization of ESM and convert it into high-valued antioxidants. An increase in dissolution rate of ESM to 66.67%–219.05% was detected, along with decrease in disulfide bonds and cysteine/cystine level induced by the steam explosion. After steam explosion pretreatment, DPPH radical scavenging rate and total antioxidant capacity of ESM hydrolysate (ESMH) were maximally increased by 87.48% and 103.09%, respectively, indicating an overwhelming advantage than unpretreated hydrolysate. Furthermore, ESMH exerted strong synergistic antioxidant activity with gallic acid (GA). Importantly, ESMH-GA mixture protected UVB-injured L929 cells by reducing reactive oxygen species and could be potentially used as antioxidant ingredients in cosmeceutical foods. This finding provided an efficient recycling strategy and direction for ESM utilization. Industrial relevanceSteam explosion is a new green and efficient processing technology. ESM with low solubility is an underutilized byproduct. This study applied steam explosion to ESM and significantly improved antioxidant activity of its hydrolysates (ESMH). ESMH protected UVB-injured L929 cells by reducing reactive oxygen species and could be potentially used as antioxidant ingredients in cosmeceutical foods. Steam explosion has the potential to be used to high-value utilization of ESM.

Salvia officinalis restores semen quality and testicular functionality in cadmium-intoxicated male rats

The present study investigated the potential ability of Salvia officinalis, one of the oldest medicinal plants, to protect male rats against cadmium reproductive toxicity. Twenty-eight healthy male rats were randomly allocated into four groups (n = 7); control, Salvia-extract treated group, cadmium treated group and a group treated with both Cd and Salvia. Administration of cadmium reduced the relative testis to body weight and significantly affected sperm parameters by decreasing motility, viability, count and increasing morphological aberrations. Comet assay was used to detect DNA fragmentation in sperms of the rats exposed to Cd. Serum levels of testosterone T, follicle stimulating hormone FSH, and luteinizing hormone LH were significantly decreased. The biochemical analysis of testicular tissue showed a significant rise in Malondialdehyde MDA level coupled with a decrease in the activity of antioxidant enzymes (superoxide dismutase SOD, glutathione peroxidase GPx and catalase CAT). The histological examination of testis sections after Cd administration revealed severe degeneration of spermatogenic cells. Seminiferous tubules were filled with homogenous eosinophilic fluid associated with atrophy of other seminiferous tubules. Co-treatment with the Salvia officinalis extract restored the oxidative enzymes activities and decreased the formation of lipid peroxidation byproduct, which in turn ameliorated the effect of Cd on sperm parameters, DNA damage and testis histopathology. Taken together, it can be concluded that the synergistic antioxidant and radical savaging activities of Salvia officinalis prevented the effect of Cd on semen quality, sperm DNA damage, along with the oxidative stress and histological abnormalities in the testis tissues.

Synergistic Antioxidant and Anti-Inflammatory Activities of Kale Juice Fermented with Limosilactobacills reuteri EFEL6901 or Limosilactobacills fermentum EFEL6800.

This study investigates the synergistic impact of fermenting kale juice with Limosilactobacillus strains on its antioxidant and anti-inflammatory properties. Kale's rich nutrient profile, especially its flavonoids, offers potential health benefits. Probiotic lactic acid bacteria are employed in kale fermentation to enhance nutrient bioavailability and generate bioactive compounds. Kale juices fermented with L. reuteri EFEL6901 or L. fermentum EFEL6800 exhibited superior microbial growth. Free sugars and amino acids were converted to alcohols and organic acids, affecting the organoleptic and health-related properties of the product. In addition, fermentation increased quercetin and kaempferol content, indicating improved availability. Furthermore, the fermented juice exhibited notable antioxidant activity and suppressed nitric oxide (NO) production, revealing anti-inflammatory potential. Gene expression analysis confirmed reduced pro-inflammatory markers such as iNOS, COX-2, IL-6, and IL-1β and elevated anti-inflammatory cytokines, including IL-10. This research highlights the promising potential of fermented kale juice, enriched with Limosilactobacillus strains, as a functional food with combined antioxidant and anti-inflammatory benefits.

Effects of κ-carrageenan on the emulsifying ability and encapsulation properties of pea protein isolate-grape seed oil emulsions

This work investigated the characteristics of pea protein isolate and κ-carrageenan complexes in stabilizing curcumin-loaded emulsions. The complexes structured by electrostatic attraction exhibited biphasic wettability with increased three-phase contact angles close to 90°. Morphological differences in the complexes were the critical factor influencing their emulsifying ability at various pH. As a steric barrier via increasing net negative charge (up to −54.7 ± 2.4 mV) and adsorbed protein content (92.57 %–97.61 %), the interfacial layer could retard droplet coalescence and improve emulsions stability. Rheological tests verified the higher viscoelasticity of emulsions by raising the oil fraction. After 4 weeks of heating treatment, the chemical stability of curcumin was prominently enhanced from 18.6 ± 0.2 % to 64.3 ± 5.7 %. The confirmed synergistic antioxidant activity between grape seed oil and curcumin in emulsions might facilitate the development of specific functional delivery systems in foods.

Exploring The in vitro Efficacy of Psidium Guajava Leaf Oil Against Cutibacterium Granulosum

One potential approach to treat acne vulgaris is by utilizing Cutibacterium granulosum (C. granulosum) to break down the biofilm formed by Cutibacterium acnes (C. acnes). When using cosmeceutical products containing certain essential oils, as they may have the unintended effect of eliminating C. granulosum, leading to the potential development of more severe acne vulgaris in the long term. No data for Psidium guajava (guava) leaves oil against C. granulosum has been reported. Therefore, this study aimed to investigate in vitro antimicrobial activity of guava leaves oil against C. granulosum. This oil was extracted from the guava leaves by hydrodistillation using a clevenger-type apparatus. Then, the chemical compositions of this crude oil were identified by gas chromatography-mass spectrometry. The percentage yield of this essential oil was 0.13 ± 0.2% (w/w) on fresh weight basis. The major compounds were β-caryophyllene (25.50%), limonene (11.58%), caryophyllene oxide (3.43%),a-copaene (2.92%), 1,8-cineole (2.08%), and a-pinene (1.28%). This essential oil exerted a potent antioxidant capacity with the half maximal inhibitory concentration of 32.7 ± 0.3 mg/ml from 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. Additionally, the essential oil of guava leaves showed the susceptibility of C. granulosum by agar disc diffusion method with 22 ± 0.2 mm of clear inhibition zone. This essential oil also possessed against C. granulosum with the minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC) of 3.125 µg/ml and 6.25 µg/ml from the broth microdilution susceptibility test. From these findings, this essential oil exhibited notable synergistic antioxidant and antimicrobial activities against C. granulosum.

A tailored slow-release film with synergistic antibacterial and antioxidant activities for ultra-persistent preservation of perishable products

Rapid decrease in antibacterial efficacy of existing active packages is difficult to promisingly prevent microbial infection during the storage of perishable products. Here, we pioneered an advanced ZnO-doped hollow carbon-encapsulated curcumin (ZHC-Cur)-chitosan (CS) slow-release film (ZHC-Cur-CS) with “nano-barricade” structure through demand-oriented tailoring of the structure and components of zeolitic imidazolate framework-8 (ZIF-8) carrier. Such an exquisite structure realized the effective sustained release of Curcumin through the dual complexity of diffusion pathway by the disordered hierarchical pore structure and steric hindrance. Prepared ZHC-Cur-CS film exhibited boosting bactericidal and antioxidant abilities by virtue of the functional synergy between curcumin and ZnO. Thus, ZHC-Cur-CS film demonstrated excellent preservation performance by significantly prolonging the shelf life of Citrus (∼2.4 times). Furthermore, the upgraded mechanical strength, improved barrier ability, and proven safety laid the foundation for its practical application. These satisfactory properties underscore the applicability of ZHC-Cur-CS film for the efficient preservation of perishable products.

Characterization of the Synergistic Antioxidant Activity of Epigallocatechin Gallate (EGCG) and Kaempferol.

Epigallocatechin gallate (EGCG) and kaempferol exhibit cellular antioxidant activity; however, their interactive effects in terms of antioxidant actions and underlying mechanisms remain unclear. In this study, their cytoprotective effects were examined against 2,2-azobis (2-amidinopropane) dihydrochloride solution (ABAP)-induced oxidative stress in HepG2 cells. The results showed that the median effective dose (EC50) of the EGCG and kaempferol (6:1.5, c/c) combination was 3.4 ± 0.1 μg/mL, with a combination index (CIavg) value of 0.54, which represented a significant synergistic effect. Further experiments proved that the combined pretreatment with EGCG and kaempferol exerted protective effects by suppressing reactive oxygen species (ROS) generation, upregulating cellular antioxidant enzyme activities (superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px)) in a dose-dependent manner. The mechanism of synergistic antioxidant effects of EGCG combined with kaempferol may be due to the up-regulation of higher antioxidant enzyme activities that improve the antioxidant capacities and balance the cell oxidative stress. The synergistic antioxidant effect of EGCG and kaempferol can provide a theoretical basis for the development of formulas of functional food ingredients.

Structural Design of Oleogel‐Hydrogel Bigels for Co‐Delivery of Curcumin and Epigallocatechin Gallate with Synergistic Stability and Bioactivity

AbstractBigels are novel biphasic systems containing hydrogel and oleogel structures, which are designed to deliver multiple bioactives for synergistic activity. The current study develops bigels based on a carrageenan hydrogel and a monoglyceride (GMS) oleogel. Results show that the microstructures of bigels are facilely modified by two surface active ingredients (Tween 20 and polyglycerol polyricinoleate), which then influence the microstructures of the bigels. When curcumin and epigallocatechin gallate (EGCG) are delivered simultaneously, the bioactives work synergistically to slow thermal degradation. Simulated digestion tests indicate that the bigel structures can delay the release of the two bioactives in artificial saliva and simulated gastric fluid (SGF), and allow fast release in simulated intestinal fluid (SIF). DPPH and ABTS tests show the digested Tween 20 bigels containing EGCG and curcumin present synergistic antioxidant activity. Anticancer activity is evaluated in human colon adenocarcinoma HCT116, and the two bioactives work cooperatively to lower cell viability. The bioactives released from Tween 20 bigels have higher cytotoxicity than those from polyglycerol polyricinoleate bigels. The results reveal that facile structural design of bigels has the potential to achieve synergistic stability and bioactivity of co‐delivered bioactives, which is meaningful for the development of functional pharmaceutical, cosmetic, and food products.