Synergistic Antioxidant Research Articles

Functional improvement of (−)-epicatechin gallate and piceatannol through combined binding to β-lactoglobulin: Enhanced effect of heat treatment and nanoencapsulation

Several polyphenol compounds commonly found in plant foods provide health benefits that promote their applications in food and pharmaceutical fields. The co-loading of proteins can improve the biological activity and synergy of combined polyphenols. Herein, multi-spectroscopic techniques and molecular docking were employed to investigate the interactions of native/heat treated β-lactoglobulin (β-LG/H-β-LG) with (−)-epicatechin gallate (ECG) and/or piceatannol (PIC). Furthermore, the synergistic antioxidant activity and cytotoxicity of ECG and PIC were demonstrated. The loading of β-LG/H-β-LG protected the antioxidant activity of ECG and PIC in the delivery systems and enhanced their cytotoxicity, stability, and bioaccessibility. Compared to the corresponding complexes, the nanoparticles of β-LG/H-β-LG had a greater impact on the functional properties and synergistic effects of ECG and PIC. The experimental results may provide a theoretical basis for the practical application of ECG and PIC co-loaded by H-β-LG, particularly H-β-LG nanoparticles in the food and pharmaceutical industries.

Optimization of Antioxidant Synergy in a Polyherbal Combination by Experimental Design.

Culinary herbs and spices are known to be good sources of natural antioxidants. Although the antioxidant effects of individual culinary herbs and spices are widely reported, little is known about their effects when used in combination. The current study was therefore undertaken to compare the antioxidant effects of crude extracts and essential oils of some common culinary herbs and spices in various combinations. The antioxidant interactions of 1:1 combinations of the most active individual extracts and essential oils were investigated as well as the optimization of various ratios using the design of experiments (DoE) approach. The 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) assays were used to determine the antioxidant activity, and MODDE 9.1® software (Umetrics AB, Umea, Sweden) was used to determine the DoE. The results revealed synergism for the following combinations: Mentha piperita with Thymus vulgaris methanol extract (ΣFIC = 0.32 and ΣFIC = 0.15 using the DPPH and FRAP assays, respectively); Rosmarinus officinalis with Syzygium aromaticum methanol extract (ΣFIC = 0.47 using the FRAP assay); T. vulgaris with Zingiber officinalis methanol extracts (ΣFIC = 0.19 using the ABTS assay); and R. officinalis with Z. officinalis dichloromethane extract (ΣFIC = 0.22 using the ABTS assay). The DoE produced a statistically significant (R2 = 0.905 and Q2 = 0.710) model that was able to predict extract combinations with high antioxidant activities, as validated experimentally. The antioxidant activities of the crude extracts from a selection of culinary herbs and spices were improved when in combination, hence creating an innovative opportunity for the future development of supplements for optimum health.

Co-assembly of egg white-derived peptides and protein-polysaccharide complexes for curcumin encapsulation: The enhancement of stability, redispersibility, and bioactivity

In this study, a nanocomposite was developed by introducing egg white-derived peptides (EWDP) into protein-polysaccharide complexes to trigger the self-assembly of EWDP for encapsulating curcumin (Cur) via the pH-driven method. In this system, EWDP could cooperate with protein-polysaccharide complexes to exert superior colloidal properties with excellent Cur aqueous solubility, redispersibility, and physical stability and act as a bioactivity amplifier to endow the delivery system with the synergistic antioxidant activity. This phenomenon was ascribed to the additional hydrophobic cavities, hydrogen bonding, and electrostatic interactions organized by EWDP. Additionally, the presence of EWDP could considerably boost the cellular antioxidant activity of Cur by decreasing reactive oxygen species (ROS) levels, improving free radical scavenging capacity, and recovering the activity of endogenous antioxidant enzymes. These findings might open up an avenue to reinforce lipophilic nutraceuticals' physicochemical properties and functionalities based on the co-assembly of food-derived peptides and protein-polysaccharide complexes.

Synergistic Antioxidant and Antimicrobial Effects of the Thymoquinone and Eugenol Combination

Synergistic Antioxidant and Antimicrobial Effects of the Thymoquinone and Eugenol Combination

Synthesis of Rutin loaded nanomagnesia as a smart nanoformulation with significant antibacterial and antioxidant properties

Nowadays synthesis of hybrid nanomaterials is of interest to researchers due to their profound antioxidant and antibacterial properties. Here, at first we prepared amine functionalized positively charged MgO nanoparticles (MgO-NH2) via microwave assisted heating followed by annealing at 400 °C for 5 h, and conjugated thereafter with a natural flavonoid, Rutin to form a bioactive nanohybrid, MgO-NH2-Rutin. The nearly spherically shaped nanohybrids with size ∼35–40 nm showed drug loading content of ∼14 % with a sustained release pattern at pH 7.4. The nanohybrids exhibited superior antioxidant properties in cell free system (DPPH, hydrogen peroxide and superoxide) as well as in intracellular condition, and showed very little cytotoxicity upto a concentration of 100 μg/mL in normal kidney epithelial cells. Besides, MgO-NH2-Rutin also triggered a significant growth inhibition against both gram positive (S. aureus) & gram negative (E. coli) bacteria. Mechanistic studies showed that the nanohybrid caused bacterial cell death via oxidative stress, DNA degradation and cell membrane disruption. Therefore, our research highlighted the use of MgO nanoparticles for the synthesis of MgO-NH2-Rutin nanohybrid, which could enhance the pharmacological actions of hydrophobic drug molecules and exhibit synergistic antioxidant and antibacterial activities.

Topical nanostructured lipid carriers of alpha-mangostin and resveratrol for synergistic antioxidant activity.

Nanostructured lipid carriers (NLCs) are interesting lipid-based carrier systems for enhancing the penetration of drugs through the skin after topical administration. Dual drug-loaded NLCs of alpha-mangostin (M) and resveratrol (R) to enhance antioxidant activity were developed for topical delivery. The efficacy of a combination of M and R was evaluated in terms of the antioxidant activity. M and R were loaded into the NLCs using a high shear homogenization and ultrasonication process. The particle size, zeta potential, and physical properties of the NLCs were observed. The M and R loading efficiency as well as release patterns were examined using Franz diffusion cells. Moreover, the antioxidant efficacy and in vitro cytotoxicity in the normal human fibroblast (NHF) of the NLCs were evaluated as well. The results found that the combination of M and R offered synergistic antioxidant activity and was successfully loaded into the NLCs with the size of a nanometer and negative zeta potential. The drugs were loaded in the NLCs as molecular dispersions and slowly released from the NLCs. Interestingly, both drugs maintained their antioxidant activity after being loaded into the NLCs and provided a higher antioxidant activity than those in the single loading of M and R, thus demonstrating that the incorporation of M and R into the NLCs allowed an enhanced antioxidant activity. Moreover, a cytotoxicity study showed that the NLCs were safe and had low cytotoxicity on the NHF cells. The M and R loaded NLCs were attractive systems for synergistic antioxidant activity for topical application.

Edaravone dexborneol protects cerebral ischemia reperfusion injury through activating Nrf2/HO-1 signaling pathway in mice.

Stroke is the leading cause of disability and death. When blood flow is restored after prolonged ischemia and hypoxia, it leads to excessive production of reactive oxygen species (ROS), increased local inflammation, and apoptosis, which are the cause of most cerebral ischemia reperfusion injury (CIRI), leading to secondary brain tissue damage. Edaravone dexborneol is a novel neuroprotective agent consisting of edaravone and borneol. Studies have shown that it has synergistic antioxidant and anti‐inflammatory effects. However, whether Edaravone dexborneol stimulates the Nrf2/HO‐1 pathway to regulate NADPH oxidase 2 (NOX2) remains unclear. In this study, wild‐type (WT) mice and Nrf2 knockout (KO) mice were used to investigate the antioxidant, anti‐inflammatory, and anti‐apoptotic effects of Edaravone dexborneol on CIRI and its mechanism. The cognitive function of mice was evaluated with the Morris water maze (MWM), test and the cell structures of hippocampus were observed by hematoxylin and eosin (H&E) staining. Nrf2, HO‐1, and NOX2 proteins and apoptosis‐related proteins Bcl‐2, Bax, and Caspase 3 were detected by western blotting. Nrf2, HO‐1, NOX2, and inflammatory factors TNF‐α, IL‐1β, IL‐4, and IL‐10 were detected by real‐time polymerase chain reaction. The results showed that Edaravone dexborneol treatment improved learning and memory performance, neuronal damage, and enhanced antioxidant, inflammation, and apoptosis in CIRI mice. In addition, Edaravone dexborneol induced the activation Nrf2/HO‐1 signaling pathway activation while inhibiting NOX2 expression. Overall, these results indicate that Edaravone dexborneol ameliorates CIRI‐induced memory impairments by activating Nrf2/HO‐1 signaling pathway and inhibiting NOX2.

GC-MS-employed phytochemical characterization, synergistic antioxidant, and cytotoxic potential of Triphala methanol extract at non-equivalent ratios of its constituents

Triphala is a famous triherbal drug, comprising three herb fruits, including Terminalia chebula (Haritaki), Terminalia bellirica (Bibhitaki), and Phyllanthus emblica (Amalaki). It is enriched with vitamin C, polyphenols, flavonoids, sterols, saponins, etc., and is well-documented for its potent antioxidant, anticancer, chemoprotective, antimicrobial, and anti-inflammatory effects. This research was conducted to evaluate the synergistic antioxidative and cytotoxic potential of mixtures of the individual constituents of Triphala at their nonequivalent ratios along with the chemical characterization of individual constituents of Triphala to identify and quantify individual compounds. The antioxidative potential was measured using total antioxidant capacity (TAC), DPPH free radical scavenging assay, and total phenolic content (TPC) tests. The cytotoxic potential was assessed on brain cancer cells (N4X4) using MTT assay, and phytochemical characterization was performed by GS-MS analysis. Nonequivalent ratios of Triphala constituents exhibited significantly higher synergistic antioxidant and cytotoxic potential than the equivalent ratios of them. Moreover, the nonequivalent ratio where the quantity of Amalaki was doubled than the other two constituents showed the highest synergistic antioxidant and cytotoxic effect. GC-MS analysis of individual constituents of Triphala identified and quantified the presence of a wide array of compounds, and fatty acid, fatty acid ester, triterpene, and aminoglycoside remained the predominant class of compounds. Thus, it can be inferred that the observed bioactivities can be attributed to the phytocompounds characterized and extracts at the nonequivalent ratio of Triphala constituents where Amalaki is doubled can be more effective in treating oxidative degenerative diseases and glioblastoma.

Synergistic Antioxidant Activity and Enhanced Stability of Curcumin Encapsulated in Vegetal Oil-Based Microemulsion and Gel Microemulsions.

Curcumin, due to its antioxidant, antibacterial, anti-inflammatory, and antitumoral activity, has attracted huge attention in applications in many fields such as pharmacy, medicine, nutrition, cosmetics, and biotechnology. The stability of curcumin-based products and preservation of antioxidant properties are still challenges in practical applications. Stability and antioxidant properties were studied for curcumin encapsulated in O/W microemulsion systems and three related gel microemulsions. Only biodegradable and biocompatible ingredients were used for carriers: grape seed oil as oily phase, Tween 80, and Plurol® Diisostearique CG as a surfactant mix, and ethanol as a co-solvent. For the gel microemulsions, water-soluble polymers, namely Carbopol® 980 NF, chitosan, and sodium hyaluronate were used. The influence of UVC irradiation and heat treatment on the degradation kinetics of curcumin in the formulations was studied. Because of the antioxidant character of the microemulsion oily phase, the possibility of a synergistic effect between grape seed oil and curcumin was explored. In this study, the high efficiency of the studied drug delivery systems to ensure protection from external degradative factors was confirmed. Also, the influence of the encapsulation in microemulsion and derived gel microemulsion systems on the antioxidant capacity curcumin was studied, and a synergistic effect with vegetal oil was demonstrated.

A ternary system of α-tocopherol with phosphatidylethanolamine and l-ascorbyl palmitate in bulk oils provides antioxidant synergy through stabilization and regeneration of α-tocopherol

The stabilization of fats and oils against oxidative lipid deterioration is still a great challenge. The synergistic interaction between phospholipids, l-ascorbate, and tocopherols have not yet been comprehensively understood. The mechanism of the synergistic antioxidant effect of 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (PE) in mixtures with l-ascorbyl palmitate (AP) and α-tocopherol (α-Toc) was investigated in an ethyl linoleate model and sunflower oil at 110 °C. The mixture of PE, AP, and α-Toc is stabilized through continuous regeneration of α-Toc from its oxidation product α-tocopherylquinone (α-TQ). This reaction is catalyzed by acids and proceeded through the formation of the α-tocopherone ion (T+) as an intermediate product. In addition to the direct reduction of T+ by AP, PE can also cause regeneration indirectly by reacting with dehydroascorbyl palmitate (DHAP) or other tricarbonyl compounds to form amino reductones. PE and AP undergo an amino-carbonyl reaction to form the condensate PE(AP)2.

Combination of Vitamin C and Curcumin Safeguards Against Methotrexate-Induced Acute Liver Injury in Mice by Synergistic Antioxidant Effects.

Methotrexate (MTX), an antineoplastic and immunosuppressive drug, widely used in the treatment of different types of cancers and the management of chronic inflammatory diseases. However, its use is associated with hepatotoxicity. Vitamin C (VC) and curcumin (CUR) exhibit anti-inflammatory and antioxidant effects. Thus, we aimed to investigate the potential hepatoprotective effects of VC and CUR pretreatment alone and in combination against MTX-induced hepatotoxicity. Albino mice were randomly divided into 7 groups: the control group, which received only normal saline; MTX group; VC group, pretreated with VC (100 or 200 mg/kg/day orally) for 10 days; CUR group, pretreated with CUR (10 or 20 mg/kg/day orally); and combination group, which received VC (100 mg/kg) and CUR (10 mg/kg). MTX was administered (20 mg/kg, intraperitoneally) to all the groups on the tenth day to induce hepatotoxicity. Forty eight hours after MTX administration, the mice were anesthetized. Blood samples were collected, the liver was removed for biochemical analysis, and a part of the tissue was preserved in formalin for histopathological analysis. The results indicated that pretreatment with a combination of VC and CUR induced a more significant decrease in the serum levels of alanine transaminase, aspartate transaminase, alkaline phosphatase, and lactic dehydrogenase and a significant increase in the tissue level of superoxide dismutase and glutathione; furthermore, it induced a significant decrease in malondialdehyde levels and improvement in histopathological changes in the liver tissues, confirming the potential hepatoprotective effects of the combination therapy on MTX-induced liver injury. To conclude, MTX-induced hepatotoxicity is mediated by induction of oxidative stress as evident by increased lipid peroxidation and reduction of antioxidant enzyme activity. Pretreatment with VC, CUR or their combination reduces the MTX-induced hepatotoxicity by antioxidant and anti-inflammatory effects. However, the combined effect of VC and CUR provided a synergistic hepatoprotective effect that surpasses pretreatment with CUR alone but seems to be similar to that of VC 200 mg/kg/day. Therefore, VC and CUR combination or a large dose of VC could be effective against MTX-induced hepatotoxicity. In this regard, further studies are warranted to confirm the combined hepatoprotective effect of VC and CUR against MTX-induced hepatotoxicity.

Effect of chitosan/starch aldehyde-catechin conjugate composite coating on the quality and shelf life of fresh pork loins.

Fresh pork is susceptible to oxidation and spoilage. Edible coating containing antioxidant and antimicrobial agents can create moisture and oxygen barriers around pork and inhibit oxidation and microbial growth in the pork. In this study, chitosan in combination with starch aldehyde-catechin conjugate (SACC) was used as a novel edible coating material for preserving fresh pork loins at chilled storage (4 ± 1°C) for 14 days. Effect of chitosan/SACC composite coating on the quality of pork loins including weight loss, colour, pH value, microbial spoilage, lipid oxidation, protein oxidation, texture and sensory attributes during chilled storage was determined. Chitosan and SACC had synergistic antioxidant and antimicrobial actions. As compared with uncoated and chitosan coated pork loins, chitosan/SACC coated pork loins showed lower weight loss (7.16%), pH value (5.99), total viable count (7.11 log CFU g-1 ), total volatile base nitrogen content (130.2mg kg-1 ), lipid oxidation level (0.47 mg malondialdehyde kg-1 ), protein oxidation level (0.047 mmol free thiol group g-1 ) and shear force (27.40 N) on day 14. Meanwhile, chitosan/SACC composite coating effectively maintained the colour, micro-structure and sensory attributes of pork loins throughout chilled storage period. The shelf life of pork loins was extended from 8 days (uncoated samples) to 14 days by chitosan/SACC composite coating. Chitosan/SACC composite coating effectively retarded the oxidation and spoilage of pork loins during chilled storage. © 2022 Society of Chemical Industry.

Estimation of Synergistic Antioxidant Effect of Methanolic Extracts of Some Medicinal Herbs

Antioxidant activity encompasses protection against cellular wear and tear by interfering in the formation of free radicals. The majority of the diseases are linked to oxidative stress generated due to these free radicals. It makes the basis for plants containing secondary metabolites showing antioxidant activity as the potential source for development of newer formulations showing action against diseases like infections, cancers and other degenerative diseases. The present study involves the study of methanolic extracts of three medicinal herbs cannabis (Cannabis sativa.), wheatgrass (Triticum aestivum) and carrot (Dascus carota L.) commonly available in Indian cultivation. The antioxidant potential of the combination of these extracts was also studied. The combinations showed a synergistic antioxidant activity suggesting that potential of natural plant extracts against any disease can be increased when used in combinations.

Cur@SF NPs alleviate Friedreich\u2019s ataxia in a mouse model through synergistic iron chelation and antioxidation

Abnormal iron metabolism, mitochondrial dysfunction and the derived oxidative damage are the main pathogeneses of Friedrich's ataxia (FRDA), a single-gene inherited recessive neurodegenerative disease characterized by progressive cerebellar and sensory ataxia. This disease is caused by frataxin (FXN) mutation, which reduces FXN expression and impairs iron sulfur cluster biogenesis. To date, there is no effective therapy to treat this condition. Curcumin is proposed harboring excellent ability to resist oxidative stress through Nrf2 activation and its newly found ability to chelate iron. However, its limitation is its poor water solubility and permeability. Here, we synthesized slow-release nanoparticles (NPs) by loading curcumin (Cur) into silk fibroin (SF) to form NPs with an average size of 150 nm (Cur@SF NPs), which exhibited satisfactory therapeutic effects on the improvement of FRDA manifestation in lymphoblasts (1 μM) derived from FRDA patients and in YG8R mice (150 mg/kg/5 days). Cur@SF NPs not only removed iron from the heart and diminished oxidative stress in general but also potentiate iron-sulfur cluster biogenesis, which compensates FXN deficiency to improve the morphology and function of mitochondria. Cur@SF NPs showed a significant advantage in neuron and myocardial function, thereby improving FRDA mouse behavior scores. These data encourage us to propose that Cur@SF NPs are a promising therapeutic compound in the application of FRDA disease.Graphical

Evaluation of the antioxidant interaction between butylated hydroxytoluene and quercetin and their utility for beef patties preservation

The present study aimed to find a mixture of BHT and quercetin with an antioxidant synergism that would enable both compounds to be used at low concentrations and, subsequently, evaluate the preservative action of the combination selected on ground beef patties stored at 4 ºC. Our results showed that quercetin possessed a higher antioxidant activity than BHT, and of the five combinations tested, a 1:5 BHT-quercetin combination presented a synergistic antioxidant activity. For the refrigerated beef patties, the 1:5 combination (5.2 and 26.0 mg/kg of BHT and quercetin, respectively) produced a beneficial action on the redness, yellowness, antioxidant capacity, metmyoglobin content, and thiobarbituric acid reactive substance value, which was similar to that produced by 100 or 36 mg/kg of BHT or quercetin (P >0.05, except the redness induced by quercetin). These benefits were compared with the data obtained from a preservative-free patty control sample (P <0.001 to <0.05). Our study shows, for the first time, that the use of a 1:5 BHT-quercetin combination was an effective, simple, and available method to preserve refrigerated beef patties, which can substitute the individual addition of high concentrations of these compounds by the meat industry.

Benzothiazole Derivatives as Multifunctional Antioxidant Agents for Skin Damage: Structure-Activity Relationship of a Scaffold Bearing a Five-Membered Ring System.

Skin diseases often give multifactorial damages; therefore, the development of multifunctional compounds represents a suitable approach especially against disorders that are induced by oxidative stress. Thus, taking into account the successful results we achieved on benzimidazoles, we have devised a new series of isosteric benzothiazoles and investigated their antioxidant, photoprotective, antifungal and antiproliferative activity. Particular attention has been paid to synergistic antioxidant and photoprotective properties. For compounds 9a and 10a, a multifunctional profile was outlined, supported by an excellent filtering capacity, mainly UVB, which has higher capacities than those of the reference PBSA which is currently in the market as a UV sunscreen filter. The two compounds were also the best in terms of growth inhibition of dermatophytes and Candida albicans, and 10a also showed good antioxidant activity. Furthermore, 9a was also effective on melanoma tumor cells (SK-Mel 5), making these compounds good candidates in the development of new skin protective and preventive agents.

NIR-regulated dual-functional silica nanoplatform for infected-wound therapy via synergistic sterilization and anti-oxidation

Nature-derived bioactive components and photothermal synergistic therapy bring potential strategies for fighting bacterial infection and accelerating would healing by virtue of their excellent therapeutic efficiencies and ignorable side effects, where photothermal property not only acts as sterilization energy but also as a doorkeeper to control the natural component release. Herein, by integrating the excellent antibacterial property of cinnamaldehyde (CA) and the outstanding photothermal performance of copper sulfide nanoparticles (CuS NPs), a multifunctional nanoplatform of SiO2 @CA@CuS nanospheres (NSs) is constructed with silica nanosphere (SiO2 NSs) as carrier. SiO2 @CA@CuS NSs exhibit photothermal property, bacterial absorption capacity, extraordinary antibacterial activity and antioxidant property. Mechanism characteriazation and antibacterial experiment indicate that positive charged SiO2 @CA@CuS can adhere to the negative charged surface of bacteria, and quickly kill bacteria through the synergistic action of the released CA and heat produced under near infrared light (NIR) irradiation at 980 nm. The sterilization efficiencies for Escherichia coli (E. coli) and S. aureus reach 99.86% and 99.84%, respectively. Furthermore, NIR-regulated SiO2 @CA@CuS perform great biocompatibility, as well as effective effects for accelerating S. aureus-infected wound healing at a low photothermal temperature (45 °C) relying on synergistic sterilization and anti-oxidation.

Green synthesis of silver nanoparticles by Pisum sativum L. (pea) pod against multidrug resistant foodborne pathogens

The consumption of foods contaminated with various foodborne organisms such as, viruses, fungi and bacteria are recognized as the important sources of foodborne illness in animals and humans. Multidrug resistant foodborne bacteria increased morbidity, mortality rates, and severe economic loss and associated with prolong hospitalization. The development of natural and novel antibacterial agent is much needed as there is an increasing concern on multidrug resistant bacteria. This study aimed to synthesize silver nanoparticles using aqeous Pisum sativum L. (pea) pod extract and to characterize the nanoparticles. It was further used on various drug resistant foodborne bacterial pathogens and antimicrobial activity was determined. The synergistic antibacterial activity, antioxidant activity and biocompatibility were also assessed. Green synthesized nanoparticles applied in this study were synthesized using aqueous P. sativum L. (pea) pod extract with particle size 30 nm. The green synthesized silver nanoparticles showed antimicrobial activity against Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, Enterococcus faecalis ATCC 700802, Streptococcus gordonii ATCC 49818, Staphylococcus aureus (MRSA) ATCC 4330 and Staphylococcus aureus ATCC 25923. Among the pathogenic bacterial strains, silver nanoparticles were highly active against S. aureus ATCC 25923 than other bacterial strains (22 ± 2 mm). The antibacterial activity varied between 15 ± 2 mm and 22 ± 2 mm diameter zone of inhibition. The MIC value of the nanoparticles ranged from 6.25 µg/mL to 75 µg/mL and MBC value ranged from 50 µg/mL to 150 µg/mL. The green synthesized nanoparticles showed antioxidant potential. Normal fibroblast cell lines (L-929) was used to test the cytotoxic activity and the increased IC50 value (750.5 ± 5.5 μg/mL) indicated good biological compatibility. The present findings revealed that green synthesized silver nanoparticles exhibited potent activity against various food borne pathogenic bacteria. These nanoparticles might be well developed as novel antibacterial substances for the treatment of food borne multidrug resistant bacterial infection.

Multispectroscopic and synergistic antioxidant study on the combined binding of caffeic acid and (-)-epicatechin gallate to lysozyme

The binding of caffeic acid (CA) and/or (-)-epicatechin gallate (ECG) to lysozyme was investigated by multispectroscopic methods and molecular docking. The effects of the single and combined binding on the structure, activity and stability of lysozyme and the synergistic antioxidant activity of CA and ECG were also studied. Fluorescence quenching spectra, time-resolved fluorescence spectra, and UV–vis absorption difference spectra all ascertained the static quenching mechanism of lysozyme by CA/ECG. Thermodynamic parameters indicated that CA and ECG competitively bound to lysozyme, and CA had a stronger binding affinity, which was consistent with the results of molecular docking. Hydrogen bonding, van der Waals’ force and electrostatic interaction were the main driving forces for the binding process. Synchronous fluorescence spectra displayed that the interaction of CA/ECG exposed the tryptophan residues of lysozyme to a more hydrophilic environment. Circular dichroism spectroscopy, Fourier transform infrared spectroscopy and dynamic light scattering indicated that the binding of CA and/or ECG to lysozyme resulted in the change of the secondary structure and increased the particle size of lysozyme. The binding of CA and/or ECG to lysozyme inhibited the enzyme activity and enhanced the thermal stability of lysozyme. The combined application of CA and ECG showed antioxidant synergy which was influenced by the encapsulation of lysozyme and cellular uptake. In summary, this work provides theoretical guidance for lysozyme as a carrier for the combined application of CA and ECG.

Study on Synergistic Antioxidant Effect of Typical Functional Components of Hydroethanolic Leaf Extract from Ginkgo Biloba In Vitro

The predicted anti-oxidation is related to apoptosis, proliferation, lipid metabolism, cell differentiation, and immune response. There are some differences in the antioxidant capacity of the four typical components of ginkgo biloba extract (EGb) including ginkgo flavone (GF), ginkgolide (G), procyanidins (OPC), and organic acids (OA), and any two members of them can exhibit apparent synergistic effects. The order of DPPH scavenging ability was: OPC > GF > OA > G. The scavenging ability of procyanidins was close to that of VC; the scavenging capacity of ABTS was GF > OPC > OA > G. The GF:OPC (1:9) showed the best synergism in scavenging DPPH and ABTS radicals. The 193 kinds of small molecules reported in EGb were obtained by analyzing the properties of EGb. In order to construct a corresponding biological activity target set, molecular docking and the network pharmacology method were employed to build the molecular action mechanism network of a compound target, and the main biological functions and signaling pathways involved with their antioxidant activities were predicted. The results displayed that the top ten compounds which belonged to the two broad categories, ginkgo flavonoids and proanthocyanidins, could interact closely with several important target proteins (CASP3, SOD2, MAPK1, HSPA4, and NQO1). This would be expected to lay a theoretical foundation for the deep development of Ginkgo biloba extract.