Lipophilization of EGCG and effects on antioxidant activities

Characterization of physicochemical properties of different epigallocatechin-3-gallate nanoparticles and their effect on bioavailability

Epigallocatechin-3-gallate (EGCG), a major catechin in green tea, exhibits potent antioxidant and disease-preventive properties, but its application is limited by poor stability and bioavailability. This study aimed to address these challenges by preparing and characterizing three EGCG-loaded nanoparticles: chitosan-EGCG-tripolyphosphate nanoparticles (CE-NPs), β-cyclodextrin-EGCG (BE-NPs), and EGCG-nanostructured lipid carriers (NE-NPs). BE-NPs exhibited the highest loading performance and retention rate under thermal environment (89.78 % after 10 h at 80 °C). NE-NPs had the highest EGCG stability in alkaline condition (45 % after 4 h at pH 7.4). Compared to free EGCG, all NPs significantly improved in vitro bioaccessibility following incubation in simulated gastrointestinal digestion for 4 h; BE-NPs enhanced oral bioavailability by 1.71 times in vivo. Additionally, CE-NPs and NE-NPs increased the relative abundance of Faecalibaculum, Erysipelotrichaceae, and Bifidobacterium in the colons of Sprague-Dawley rats. These findings suggest that BE-NPs are a promising nano-delivery system for enhancing EGCG stability and bioavailability in healthy organisms.

Fabrication and characterization of decanoyl chloride/curcumin-modified potato starch nanoparticles and the potential application in the stabilization of flaxseed oil-in-water Pickering emulsions

In the current study, gelatinized potato starch was modified by decanoyl chloride and curcumin via esterification and pH-driven method at two pH levels (pH 8 and 12), respectively, followed by precipitation and formation of anionic nanoparticles. The effects of modifications on the various properties of starch nanoparticles were investigated. A decrease in mean particle diameter and branching degree as well as an increase in product mass, fatty acid substitution degree (0.043 to 0.049), curcumin encapsulation efficiency (83.0 % to 86.7 %), and absolute zeta-potential value (-30.3 to -41.2 mV) were observed at pH 12 compared to pH 8. The starch esterification process was confirmed by FTIR and 1H NMR analyses. XRD results revealed changes in the crystallinity index and the crystal pattern from B-type in native starch to V-type in modified starch nanoparticles. Contact angle values of different modified nanoparticles ranged from 85.9° to 130.9°. Pickering emulsions with a mean diameter of 6.79 μm and a zeta-potential value of -30.5 mV were stabilized by decanoyl chloride/curcumin-modified starch nanoparticles. Bright-field microscopy and confocal Raman spectral mapping of Pickering emulsion droplets confirmed the adsorption of modified starch nanoparticles at the interfacial layer. Tailored particle size and hydrophobicity might provide potential advantages for tuning the properties of Pickering emulsions stabilized by these nanoparticles.

The circadian rhythm: A new target of natural products that can protect against diseases of the metabolic system, cardiovascular system, and nervous system

BACKGROUND

The treatment of metabolic system, cardiovascular system, and nervous system diseases remains to be explored. In the internal environment of organisms, the metabolism of substances such as carbohydrates, lipids and proteins (including biohormones and enzymes) exhibit a certain circadian rhythm to maintain the energy supply and material cycle needed for the normal activities of organisms. As a key factor for the health of organisms, the circadian rhythm can be disrupted by pathological conditions, and this disruption accelerates the progression of diseases and results in a vicious cycle. The current treatments targeting the circadian rhythm for the treatment of metabolic system, cardiovascular system, and nervous system diseases have certain limitations, and the identification of safer and more effective circadian rhythm regulators is needed.

AIM OF THE REVIEW

To systematically assess the possibility of using the biological clock as a natural product target for disease intervention, this work reviews a range of evidence on the potential effectiveness of natural products targeting the circadian rhythm to protect against diseases of the metabolic system, cardiovascular system, and nervous system. This manuscript focuses on how natural products restore normal function by affecting the amplitude of the expression of circadian factors, sleep/wake cycles and the structure of the gut microbiota.

KEY SCIENTIFIC CONCEPTS OF THE REVIEW

This work proposes that the circadian rhythm, which is regulated by the amplitude of the expression of circadian rhythm-related factors and the sleep/wake cycle, is crucial for diseases of the metabolic system, cardiovascular system and nervous system and is a new target for slowing the progression of diseases through the use of natural products. This manuscript provides a reference for the molecular modeling of natural products that target the circadian rhythm and provides a new perspective for the time-targeted action of drugs.

Ultrasound-assisted preparation of wax-based composite gelator: Structural characterisation, in vitro antioxidant activity and application in oleogels

In recent years, the development of zero-trans fatty acid products instead of traditional hydrogenated and high-unsaturated fatty acid animal and vegetable oils has been an increasing interest in the field of food. This paper focused on the ultrasound-assisted preparation of a novel wax-based composite gelator loaded with natural antioxidant to prepare oleogels with good storage oxidation stability. The preparation of the wax-based composite gelator was to first form the anthocyanin (ACNs) and soyabean lecithin (SL) complex, and then homogenized with beeswax (BW). A complex maximum association efficiency of 86.43 % was achieved when the combination was performed for 50 min at 40 °C and 270 W ultrasonic power, and exhibited higher lipophilicity. Moreover, structural analysis results revealed that ultrasonic-assisted treatment accelerated the formation of ACNs and SL ultrasonic complexes (ASUC) by the hydrogen bonding. The results of gelators indicated the ASUC-BW composite gelator showed the highest ACNs embedding rate of 72.91 % and better antioxidant activity. XRD analysis and thermogravimetric analysis demonstrated that ASUC-BW composite gelator maintained β' crystal structure and had higher thermal stability due to physical interactions between ASUC and beeswax. Accelerated storage tests at 60 °C revealed that oleogels prepared by ASUC-BW composite gelator (ALO) had significantly lower peroxide values (PV) (14.0 mmol/kg) and thiobarbituric acid reactive substances (TBARS) (1.8 mg/kg). Overall, this paper demonstrates ultrasonic-assisted treatment is an effective way to improve dispersion and availability of ANCs in food rich in oil and can be further applied to developing novel high stability fatty food systems.

Phytochemical-mediated efferocytosis and autophagy in inflammation control

Efferocytosis, the clearance of apoptotic cells, is a critical process that maintains tissue homeostasis and immune regulation. Defective efferocytosis is linked to the development of chronic inflammatory conditions, including atherosclerosis, neurological disorders, and autoimmune diseases. Moreover, the interplay between autophagy and efferocytosis is crucial for inflammation control, as autophagy enhances the ability of phagocytic cells. Efficient efferocytosis, in turn, regulates autophagic pathways, fostering a balanced cellular environment. Dysregulation of this balance can contribute to the pathogenesis of various disorders. Phytochemicals, bioactive compounds found in plants, have emerged as promising therapeutic agents owing to their diverse pharmacological properties, including antioxidant, anti-inflammatory, and immunomodulatory effects. This review aims to highlight the pivotal role of phytochemicals in enhancing efferocytosis and autophagy and explore their potential in the prevention and treatment of related disorders. This study examines how phytochemicals influence key aspects of efferocytosis, including phagocytic cell activation, macrophage polarization, and autophagy induction. The therapeutic potential of phytochemicals in atherosclerosis and neurological diseases is highlighted, emphasizing their ability to enhance efferocytosis and autophagy and reduce inflammation. This review also discusses innovative approaches, such as nanoformulations and combination therapies to improve the targeting and bioavailability of phytochemicals. Ultimately, this study inspires further research and clinical applications in phytochemical-mediated efferocytosis enhancement for managing chronic inflammatory and autoimmune conditions.

Enzyme-esterified grape seed proanthocyanidin derivatives as novel lipid-lowering agents

Grape seed proanthocyanidin (GSP), as a natural antioxidant, has great potential to be developed into a lipid-lowering agent, but its low lipophilicity and stability greatly limit its application. In this study, an enzymatic esterification strategy was developed to introduce fatty acid chains into GSP, resulting in the successful synthesis of a series of new GSP derivatives. The results showed that up to 85% conversion of GSP and 35% TAG inhibition rate of GSP derivatives were achieved. The structures of GSP derivatives were identified by UPLC-MS/MS, and seven derivatives were confirmed as catechin-3'-O-laurate, epicatechin-3'-O-laurate, epicatechin gallate-3″,5″-di-O-laurate, epicatechin gallate-3',3″,5″-tri-O-laurate, procyanidin B1-3',3″-di-O-laurate, procyanidin B2-3',3″-di-O-laurate and procyanidin C1-3',3″,3‴-tri-O-laurate by NMR. GSP derivatives exhibited higher inhibitory effects on lipid accumulation, intracellular TAG and TC than parent GSP. These results indicate that GSP derivatives have potential as lipid-lowering agents for utilization in the food industry.

Epigallocatechin gallate modification of physicochemical, structural and functional properties of egg yolk granules

The aim of this study was to prepare protein-polyphenol covalent complexes by treating egg yolk granules (EYG) with alkali in the presence of epigallocatechin gallate (EGCG) and characterize the physicochemical, structural, and functional properties of these covalent complexes. Results revealed that the optimal covalent binding occurred when the concentration of EGCG reached 0.15% (w/w), resulting in a grafting rate of 1.51 ± 0.03%. As the amount of EGCG increased, corresponding increases were observed in the particle size and ζ-potential of the complexes, thereby enhancing their stability. Furthermore, our analysis using fluorescence spectroscopy, FTIR, SEM, and SDS-PAGE collectively demonstrated the formation of a covalent complex between EYG and EGCG. Notably, the covalent complexes exhibited improved antioxidant activity and emulsifying properties. Overall, this study establishes a theoretical framework for the future practical application of EYG, emphasizing the potential of EGCG to modify its structural and functional characteristics.

Epigallocatechin-3-gallate stabilizes aqueous curcumin by generating nanoparticles and its application in beverages

In this study, we addressed the limited water solubility of curcumin by utilizing epigallocatechin-3-gallate to form nanoparticles through self-assembly. The resulting particles, ranging from 100 to 150 nm, exhibited a redshift in the UV-visible spectrum, from 425 nm to 435 nm, indicative of potential π-π stacking. Molecular docking experiments supported this finding. Curcumin loaded with epigallocatechin-3-gallate showed exceptional dispersibility in aqueous solutions, with 90.92 % remaining after 60 days. The electrostatic screening effect arises from the charge carried by epigallocatechin-3-gallate on the nanoparticles, leading to enhanced retention of curcumin under different pH, temperature, and ionic strength conditions. Furthermore, epigallocatechin-3-gallate can interact with other hydrophobic polyphenols, improving their dispersibility and stability in aqueous systems. Applying this principle, a palatable beverage was formulated by combining turmeric extract and green tea. The nanoparticles encapsulated with epigallocatechin-3-gallate show potential for improving the applicability of curcumin in aqueous food systems.

Epigallocatechin gallate protects MC3T3-E1 cells from cadmium-induced apoptosis and dysfunction via modulating PI3K/AKT/mTOR and Nrf2/HO-1 pathways

Epigallocatechin gallate (EGCG), an active constituent of tea, is recognized for its anticancer and anti-inflammatory properties. However, the specific mechanism by which EGCG protects osteoblasts from cadmium-induced damage remains incompletely understood. Here, the action of EGCG was investigated by exposing MC3T3-E1 osteoblasts to EGCG and CdCl2 and examining their growth, apoptosis, and differentiation. It was found that EGCG promoted the viability of cadmium-exposed MC3T3-E1 cells, mitigated apoptosis, and promoted both maturation and mineralization. Additionally, CdCl2 has been reported to inhibit both the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) and nuclear factor erythroid 2-related factor 2/heme oxygenase-1(Nrf2/HO-1) signaling pathways. EGCG treatment attenuated cadmium-induced apoptosis in osteoblasts and restored their function by upregulating both signaling pathways. The findings provide compelling evidence for EGCG's role in attenuating cadmium-induced osteoblast apoptosis and dysfunction through activating the PI3K/AKT/mTOR and Nrf2/HO-1 pathways. This suggests the potential of using EGCG for treating cadmium-induced osteoblast dysfunction.

Comprehensive Review of EGCG Modification: Esterification Methods and Their Impacts on Biological Activities

Epigallocatechin gallate (EGCG), the key constituent of tea polyphenols, presents challenges in terms of its lipid solubility, stability, and bioavailability because of its polyhydroxy structure. Consequently, structural modifications are imperative to enhance its efficacy. This paper comprehensively reviews the esterification techniques applied to EGCG over the past two decades and their impacts on bioactivities. Both chemical and enzymatic esterification methods involve catalysts, solvents, and hydrophobic groups as critical factors. Although the chemical method is cost-efficient, it poses challenges in purification; on the other hand, the enzymatic approach offers improved selectivity and simplified purification processes. The biological functions of EGCG are inevitably influenced by the structural changes incurred through esterification. The antioxidant capacity of EGCG derivatives can be compromised under certain conditions by reducing hydroxyl groups, while enhancing lipid solubility and stability can strengthen their antiviral, antibacterial, and anticancer properties. Additionally, esterification broadens the utility of EGCG in food applications. This review provides critical insights into developing cost-effective and environmentally sustainable selective esterification methods, as well as emphasizes the elucidation of the bioactive mechanisms of EGCG derivatives to facilitate their widespread adoption in food processing, healthcare products, and pharmaceuticals.

Injectable hydrogel with antimicrobial and anti-inflammatory properties for postoperative tumor wound care

Clinically, tumor removal surgery leaves irregularly shaped wounds that are susceptible to bacterial infection and further lead to excessive inflammation. Injectable hydrogel dressings with antimicrobial and anti-inflammatory properties have been recognized as an effective strategy to care for postoperative tumor wounds and prevent recurrence in recent years. In this work, we constructed a hydrogel network by ionic bonding interactions between quaternized chitosan (QCS) and epigallocatechin gallate (EGCG)-Zn complexes which were coordinated by EGCG and zinc ions. Because of the synergistic effect of QCS and EGCG-Zn, the hydrogel exhibited outstanding antimicrobial capacity (>99.9% inhibition), which could prevent infections caused byEscherichia coli and Staphylococcus aureus. In addition, the hydrogel was able to inhibit the growth of mice breast cancer cells (56.81% survival rate within 72 h) and reduce inflammation, which was attributed to the sustained release of EGCG. The results showed that the hydrogel was effective in inhibiting tumor recurrence and accelerating wound closure when applied to the postoperative tumor wounds. This study provided a simple and reliable strategy for postoperative tumor wound care using antimicrobial and anti-inflammatory injectable dressings, confirming their great potential in the field of postoperative wound dressings.

Caffeic acid derivative WSY6 protects melanocytes from oxidative stress by reducing ROS production and MAPK activation

Purpose

Vitiligo is a chronic depigmentation disease caused by a loss of functioning melanocytes and melanin from the epidermis. Oxidative stress-induced damage to melanocytes is key in the pathogenesis of vitiligo. WSY6 is a caffeic acid derivative synthesized from epigallocatechin-3-gallate (EGCG). This study is to investigate whether the new chemical WSY6 protected melanocytes from H2O2-induced cell damage and to elucidate the underlying molecular mechanism.

Patients and methods

The present study compared the antioxidative potential of WSY6 with EGCG in hydrogen peroxide (H2O2)-treated PIG1 cells. Western blotting was used to study the protein expression of cyto-c, cleaved-caspase3, cleaved-caspase9, and the activation of MAPK family members, including p38, ERK1/2, JNK and their phosphorylation in melanocytes. ROS assay kit to detect intracellular reactive oxygen species production; CCK8 and lactate dehydrogenase leak assay to detect cytotoxicity.

Results

EGCG and WSY6 ameliorated H2O2-induced oxidative stress damage in PIG1 cells in a does-dependent manner, while WSY6 was much more effective. WSY6 reduced cellular ROS production, cytochrome c release, downregulated caspase-3 and caspase-9 activation. MAPK pathway signaling including phosphorylated p38, ERK and JNK were observed under oxidative stress and can be much protected by pre-treatment of WSY6.

Conclusion

These results indicated that WSY6 could be a more powerful antioxidant than EGCG and protect melanocytes against oxidative cytotoxicity.

Effect of structural stability of lipase in acetonitrile on its catalytic activity in EGCG esterification reaction: FTIR and MD simulation

In this study, (-)-Epigallocatechin-3-O-gallate (EGCG) esterification reaction was catalyzed by Novozym 435, Lipozyme RM, Lipozyme TLIM, and lipase Amano 30SD in acetonitrile. Fourier transform infrared spectroscopy (FTIR) and molecular dynamic (MD) simulations were used to analyze the structural stability of different lipases in acetonitrile and their effect on EGCG esterification reaction. The results showed that conversion rate of EGCG catalyzed by Lipozyme RM was the highest, followed by Lipozyme TLIM. FTIR indicated that the secondary structure of Lipozyme RM was the most stable. MD simulations suggested that whole structural stability of Lipozyme RM in acetonitrile was superior to Novozym 435 and lipase Amano 30SD and similar to Lipozyme TLIM due to their similar conformation, while the active site of Lipozyme RM is more flexible than that of Lipozyme TLIM, which indicated that lipase with stable whole structure and flexible active site may be more conducive to the esterification of EGCG in acetonitrile. This study provided a direction for rapidly screening lipase to synthetize EGCG or other polyphenols esterified derivatives.

Multifunctional liposomes Co-encapsulating epigallocatechin-3-gallate (EGCG) and miRNA for atherosclerosis lesion elimination

Atherosclerosis (AS) is a chronic inflammatory disease, characterized by a lipid accumulated plaque. Anti-oxidative and anti-inflammation and lipid metabolism promoting therapeutic strategies have been applied for atherosclerosis treatment. However, the therapeutic effect of a single therapeutic method is limited. It is suggested that a combination of these two strategies could help prevent lipid accumulation caused by inflammation and oxidative stress, and also promote lipid efflux from atherosclerotic plaque, to normalize arteries to the maximum extent. Hence, a strategy involving a multifunctional liposome co-encapsulating an antioxidant and anti-inflammatory drug epigallocatechin-3-gallate (EGCG) and a lipid-efflux-promoting gene miR-223 was established. The system (lip@EGCG/miR-223) could encapsulate miR-223 in core areas of the liposomes to provide a protective effect for gene drugs. Moreover, lip@EGCG/miR-223 was smaller in size (91.28 ± 2.28 nm characterized by DLS), making it easier to target AS lesions, which have smaller vascular endothelial spaces. After being efficiently internalized into the cells, lip@EGCG/miR-223 exhibited excellent antioxidant and anti-inflammatory effects in vitro by eliminating overproduced ROS and decreasing the level of inflammatory cytokines (TNF-α, IL-1β, and MCP-1), which was due to the effect of EGCG. Besides, the lipid-efflux-promoting protein ABCA1 was upregulated when treated with lip@EGCG/miR-223. Through the two therapies mentioned, lip@EGCG/miR-223 could effectively inhibit the formation of foam cells, which are a main component of atherosclerotic plaques. In AS model mice, after intravenous (i.v.) administration, lip@EGCG/miR-223 was effectively accumulated in atherosclerotic plaques, and the distribution of drugs in the heart and aorta compared to that in the kidney was significantly increased when compared with free drugs (the ratio was 6.27% for the free miR-223-treated group, which increased to 66.10% for the lip@EGCG/miR-223-treated group). By decreasing the inflammation level and lipid accumulation, the arterial vessels in AS were normalized, with less macrophages and micro-angiogenesis, when treated with lip@EGCG/miR-223. Overall, this study demonstrated that lip@EGCG/miR-223 could be developed as a potential system for atherosclerosis treatment by a combined treatment of antioxidant, anti-inflammatory, and lipid-efflux-promoting effects, which provides a novel strategy for the safe and efficient management of atherosclerosis.

Enzymatic molecular modification of water-soluble polyphenols: Synthesis, structure, bioactivity and application

The poor lipophilicity and instability of water-soluble polyphenols limit their bioavailability and application in food. However, increasing attention has been given to water-soluble polyphenols due to their multiple biological activities, which prompts the modification of the structure of water-soluble polyphenols to improve their lipophilicity and stability and enable more efficient application. This review presents the enzymatic biosynthesis of lipophilic derivatives of water-soluble polyphenols, which will change the molecular structure of water-soluble polyphenols based on the loss of hydroxyl or carboxyl groups. Therefore, the effects of reaction factors on the structure of polyphenol derivatives and the change in their bioactivities will be further analyzed. Previous studies have shown that lipases, solvent systems, and hydrophobic groups are major factors influencing the synthesis and lipophilicity of polyphenol derivatives. Moreover, the biological activities of polyphenol derivatives were changed to a certain extent, such as through the enhancement or weakening of antioxidant activity in different systems and the increase in anti-influenza virus activity and antibacterial activity. The improvement of lipophilicity also expands polyphenol application in food. This review may contribute to the efficient synthesis of lipophilic derivatives of water-soluble polyphenols to extend the utilization and application range of polyphenols.

A local dark tea - Liubao tea - extract exhibits remarkable performance in oral tissue regeneration, inflammation relief and oral microbiota reconstruction

The prevalence of oral health problems is ubiquitous in contemporary society, with particular emphasis placed on the central role of oral flora in mitigating this issue. Both ancient literature and modern research have highlighted the promising application of tea with substantial bioactive properties, particularly dark tea, in preserving and promoting oral health. Liubao tea, a widely consumed dark tea with increasing popularity in recent years, has been reported to possess abundant bioactive constituents, exhibit remarkable antioxidant and anti-inflammatory effects, modulate the flora structure and so on. It may be a promising candidate for addressing oral health problems. In this study, Liubao tea was meticulously extracted, purified and identified, followed by an investigation of its potential to modulate oral microecology by virtue of an acetic acid-induced oral disorder murine model. The results revealed that Liubao tea extract (LTE) application commendably reconstructed the oral mucosal barrier, promoted tissue regeneration and mitigated micro-inflammation. Furthermore, LTE treatment could also ameliorate the oral flora composition by decreasing the abundance of Proteobacteria and increasing the abundance of Firmicutes and Actinobacteria at the phylum level, as well as inhibiting pernicious bacteria such as Streptococcus and Delftia acidovorans. So, it could promote the generation of a beneficial microenvironment and regulate the immune process. Overall, LTE demonstrated remarkable potential in regulating the balance of oral microecology, suggesting that it may represent a promising therapeutic strategy for oral health concerns.

A General and Efficient Strategy for Gene Delivery Based on Tea Polyphenols Intercalation and Self-Polymerization

Gene therapy that employs therapeutic nucleic acids to modulate gene expression has shown great promise for diseases therapy, and its clinical application relies on the development of effective gene vector. Herein a novel gene delivery strategy by just using natural polyphenol (-)-epigallocatechin-3-O-gallate (EGCG) as raw material is reported. EGCG first intercalates into nucleic acids to yield a complex, which then oxidizes and self-polymerizes to form tea polyphenols nanoparticles (TPNs) for effective nucleic acids encapsulation. This is a general method to load any types of nucleic acids with single or double strands and short or long sequences. Such TPNs-based vector achieves comparable gene loading capacity to commonly used cationic materials, but showing lower cytotoxicity. TPNs can effectively penetrate inside cells, escape from endo/lysosomes, and release nucleic acids in response to intracellular glutathione to exert biological functions. To demonstrate the in vivo application, an anti-caspase-3 small interfering ribonucleic acid is loaded into TPNs to treat concanavalin A-induced acute hepatitis, and excellent therapeutic efficacy is obtained in combination with the intrinsic activities of TPNs vector. This work provides a simple, versatile, and cost-effective gene delivery strategy. Given the biocompatibility and intrinsic biofunctions, this TPNs-based gene vector holds great potential to treat various diseases.

Lipase-mediated flow synthesis of nature-inspired phenolic carbonates

A facile and convenient lipase-catalyzed flow approach for the chemoselective synthesis of tyrosol and hydroxytyrosol methyl carbonates has been developed in neat dimethylcarbonate. The products were obtained in quantitative yield with high catalyst productivity. The biocatalytic approach was then exploited for the preparation of value-added symmetrical tyrosol and hydroxytyrosol carbonates.

From polyphenol to o-quinone: Occurrence, significance, and intervention strategies in foods and health implications

Polyphenol oxidation is a chemical process impairing food freshness and other desirable qualities, which has become a serious problem in fruit and vegetable processing industry. It is crucial to understand the mechanisms involved in these detrimental alterations. o-Quinones are primarily generated by polyphenols with di/tri-phenolic groups through enzymatic oxidation and/or auto-oxidation. They are highly reactive species, which not only readily suffer the attack by nucleophiles but also powerfully oxidize other molecules presenting lower redox potentials via electron transfer reactions. These reactions and subsequent complicated reactions are capable of initiating quality losses in foods, such as browning, aroma loss, and nutritional decline. To attenuate these adverse influences, a variety of technologies have emerged to restrain polyphenol oxidation via governing different factors, especially polyphenol oxidases and oxygen. Despite tremendous efforts devoted, to date, the loss of food quality caused by quinones has remained a great challenge in the food processing industry. Furthermore, o-quinones are responsible for the chemopreventive effects and/or toxicity of the parent catechols on human health, the mechanisms by which are quite complex. Herein, this review focuses on the generation and reactivity of o-quinones, attempting to clarify mechanisms involved in the quality deterioration of foods and health implications for humans. Potential innovative inhibitors and technologies are also presented to intervene in o-quinone formation and subsequent reactions. In future, the feasibility of these inhibitory strategies should be evaluated, and further exploration on biological targets of o-quinones is of great necessity.

Interfacial behavior of gallic acid and its alkyl esters in stripped soybean oil in combination with monoacylglycerol and phospholipid

The effect of gallic acid alkyl esters and their combination with monoacylglycerol (MAG) and 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) on the formation of hydroperoxides and hexanal were determined during the oxidation of stripped soybean oil. Interfacial tension, water content, and droplet size were evaluated to monitor the physical properties of the oil system. Adding MAG and DOPC, especially MAG/DOPC, to the oil promoted the partitioning of antioxidants into the water-oil interfaces by further reducing the interfacial tension. The stripped oil containing methyl gallate (MG) accompanied by MAG/DOPC had lower values of the critical micelle concentration of hydroperoxides and larger micellar size at the induction period. This confirms that MG was able to more effectively reduce the free hydroperoxides concentration and inhibit them in an interfacial way. The conjunction of surfactants has been shown as a promising strategy to improve the interfacial and antioxidant activity of gallates in the oxidative stability of soybean oil.

Stability of glycosylated complexes loaded with Epigallocatechin 3-gallate (EGCG)

The application of Epigallocatechin-3-gallate (EGCG) in food industry was limited by its low stability in aqueous solutions and poor bioavailability in vivo. The novel EGCG glycosylated arachin nanoparticles (Ara-CMCS-EGCG) and EGCG glycosylated casein nanoparticles (Cas-CMCS-EGCG) were prepared to improve the stability and bioavailability of EGCG. The effect of different variables on the storage stability and the slow-release behavior of novel glycosylation complexes in nanoparticle background solution and artificial gastrointestinal fluid were investigated. The results showed that the DPPH scavenging activity of Ara-CMCS-EGCG and Cas-CMCS-EGCG were stable in temperature (25 ∼ 70 °C). EGCG could enhance the crosslinking effect of molecular particles in glycosylation complexes solution. The glycosylated protein nanoparticles were stable to acid-base and enzymolysis in simulated gastrointestinal fluid. The release rate of EGCG in simulated intestinal fluid was higher than that in simulated gastric fluid. The glycosylated protein carrier can not only release EGCG slowly, but also significantly improve the stability and bioavailability of EGCG in simulated gastrointestinal fluid.

An EGCG-mediated self-assembled micellar complex acts as a bioactive drug carrier

Epigallocatechin gallate (EGCG) has attracted the increasing attention of many researchers, especially in the field of tumor therapy. However, EGCG has poor fat solubility, low stability, low bioavailability, and a high effective dose in vivo. Traditional drug delivery methods are difficult to deliver the water-soluble EGCG efficiently and in high doses to tumor sites. To address these issues, a new type of strategy has been tried in this study to transform EGCG from a "Bioactive natural ingredient" into a "Bioactive drug carrier". Briefly, the EGCG was modified with a fat-soluble 9-fluorene methoxy carbonyl (Fmoc) motif, and the obtained EGCG-Fmoc showed a considerable improvement in lipid solubility and stability. Interestingly, EGCG-Fmoc obtained the characteristic of self-assembly in water, making it easier to take up by tumor cells. Furthermore, the self-assembled nanocomplex exhibited paclitaxel encapsulation performance and could achieve the dual delivery of EGCG and paclitaxel.

Monomeric compounds from traditional Chinese medicine: New hopes for drug discovery in pulmonary fibrosis

Pulmonary fibrosis (PF) is a chronic and irreversible pulmonary disease, and can lead to decreased lung function, respiratory failure and even death. The pathogenesis research and treatment strategy of PF significantly lag behind the medical progress and clinical needs. The treatment of this disease remains a thorny clinical problem, and the effective therapeutic drugs are still limited. Monomeric compounds from traditional Chinese medicine own various biological activities and high safety. They play a broad part in treating diseases and is also a candidate drug for preventing and treating PF. In this paper, we reviewed the mechanism of action and potential value of various anti-PF monomeric compounds from traditional Chinese medicine. These monomeric compounds can attenuate inflammatory response, oxidative stress, epithelial mesenchymal transformation and other processes of lung through many signaling pathways, and inhibit the activation and differentiation of fibroblasts, thus contributing to the treatment of PF. This review can provide new ideas for the development of anti-PF drugs in high efficiency with low toxicity.

Changes in N-nitrosamines, residual nitrites, lipid oxidation, biogenic amines, and microbiota in Chinese sausages following treatment with tea polyphenols and their palmitic acid–modified derivatives

This study aimed to investigate the effects of tea polyphenol (TP), epigallocatechin gallate (EGCG), and their palmitic acid-modified derivatives palmitoyl-TP (pTP) and palmitoyl-EGCG (pEGCG) on the accumulation of N-nitrosamine and biogenic amines (BAs), residual nitrites, and lipid oxidation in Chinese sausages. The microorganisms, color, and texture properties of sausages were evaluated. TP, EGCG, pTP, or pEGCG significantly inhibited the accumulation of N-nitrosodimethylamine (NDMA) and BAs, residual nitrites, and lipid oxidation, but enhanced the redness, hardness, and chewiness of sausages. The concentration of NDMA in sausages was reduced by 58.11%, 63.51%, 36.49%, and 44.59%, respectively, after treatment with TP, EGCG, pTP, and pEGCG. Both EGCG and pEGCG exhibited excellent inhibitory effects on the predominant BAs, including putrescine, tyramine, cadaverine, histamine, and 2-phenylethylamine. Palmitoyl-EGCG was found to be the strongest inhibitor of lipid oxidation. Besides, the four antioxidants weakly affected the population of total aerobic bacteria and lactic acid bacteria but totally suppressed the growth of undesirable Enterobacteriaceae. The principal component and correlation analyses proved that BAs, nitrites, lipid oxidation, and microbiota were responsible for the formation of NDMA. The results indicated that palmitic acid-modified TPs and similar derivatives might serve as potential preservatives to improve the safety and quality of fermented meat products.

Development and Optimisation of Inhalable EGCG Nano-Liposomes as a Potential Treatment for Pulmonary Arterial Hypertension by Implementation of the Design of Experiments Approach

Epigallocatechin gallate (EGCG), the main ingredient in green tea, holds promise as a potential treatment for pulmonary arterial hypertension (PAH). However, EGCG has many drawbacks, including stability issues, low bioavailability, and a short half-life. Therefore, the purpose of this research was to develop and optimize an inhalable EGCG nano-liposome formulation aiming to overcome EGCG's drawbacks by applying a design of experiments strategy. The aerodynamic behaviour of the optimum formulation was determined using the next-generation impactor (NGI), and its effects on the TGF-β pathway were determined using a cell-based reporter assay. The newly formulated inhalable EGCG liposome had an average liposome size of 105 nm, a polydispersity index (PDI) of 0.18, a zeta potential of -25.5 mV, an encapsulation efficiency of 90.5%, and a PDI after one month of 0.19. These results are in complete agreement with the predicted values of the model. Its aerodynamic properties were as follows: the mass median aerodynamic diameter (MMAD) was 4.41 µm, the fine particle fraction (FPF) was 53.46%, and the percentage of particles equal to or less than 3 µm was 34.3%. This demonstrates that the novel EGCG liposome has all the properties required to be inhalable, and it is expected to be deposited deeply in the lung. The TGFβ pathway is activated in PAH lungs, and the optimum EGCG nano-liposome inhibits TGFβ signalling in cell-based studies and thus holds promise as a potential treatment for PAH.

Structural Features of Small Molecule Antioxidants and Strategic Modifications to Improve Potential Bioactivity

This review surveys the major structural features in various groups of small molecules that are considered to be antioxidants, including natural and synthetic compounds alike. Recent advances in the strategic modification of known small molecule antioxidants are also described. The highlight is placed on changing major physicochemical parameters, including log p, bond dissociation energy, ionization potential, and others which result in improved antioxidant activity.

Trained immunity in monocyte/macrophage: Novel mechanism of phytochemicals in the treatment of atherosclerotic cardiovascular disease

Atherosclerosis (AS) is the pathology of atherosclerotic cardiovascular diseases (ASCVD), characterized by persistent chronic inflammation in the vessel wall, in which monocytes/macrophages play a key role. It has been reported that innate immune system cells can assume a persistent proinflammatory state after short stimulation with endogenous atherogenic stimuli. The pathogenesis of AS can be influenced by this persistent hyperactivation of the innate immune system, which is termed trained immunity. Trained immunity has also been implicated as a key pathological mechanism, leading to persistent chronic inflammation in AS. Trained immunity is mediated via epigenetic and metabolic reprogramming and occurs in mature innate immune cells and their bone marrow progenitors. Natural products are promising candidates for novel pharmacological agents that can be used to prevent or treat cardiovascular diseases (CVD). A variety of natural products and agents exhibiting antiatherosclerotic abilities have been reported to potentially interfere with the pharmacological targets of trained immunity. This review describes in as much detail as possible the mechanisms involved in trained immunity and how phytochemicals of this process inhibit AS by affecting trained monocytes/macrophages.

Recent Progress in Research on Mechanisms of Action of Natural Products against Alzheimer's Disease: Dietary Plant Polyphenols

Alzheimer's disease (AD) is an incurable degenerative disease of the central nervous system and the most common type of dementia in the elderly. Despite years of extensive research efforts, our understanding of the etiology and pathogenesis of AD is still highly limited. Nevertheless, several hypotheses related to risk factors for AD have been proposed. Moreover, plant-derived dietary polyphenols were also shown to exert protective effects against neurodegenerative diseases such as AD. In this review, we summarize the regulatory effects of the most well-known plant-derived dietary polyphenols on several AD-related molecular mechanisms, such as amelioration of oxidative stress injury, inhibition of aberrant glial cell activation to alleviate neuroinflammation, inhibition of the generation and promotion of the clearance of toxic amyloid-β (Aβ) plaques, inhibition of cholinesterase enzyme activity, and increase in acetylcholine levels in the brain. We also discuss the issue of bioavailability and the potential for improvement in this regard. This review is expected to encourage further research on the role of natural dietary plant polyphenols in the treatment of AD.

Green Tea Polyphenol (-)-Epigallocatechin-3-Gallate (EGCG): A Time for a New Player in the Treatment of Respiratory Diseases?

(-)-Epigallocatechin-3-gallate (EGCG) is a major polyphenol of green tea that possesses a wide variety of actions. EGCG acts as a strong antioxidant which effectively scavenges reactive oxygen species (ROS), inhibits pro-oxidant enzymes including NADPH oxidase, activates antioxidant systems including superoxide dismutase, catalase, or glutathione, and reduces abundant production of nitric oxide metabolites by inducible nitric oxide synthase. ECGC also exerts potent anti-inflammatory, anti-fibrotic, pro-apoptotic, anti-tumorous, and metabolic effects via modulation of a variety of intracellular signaling cascades. Based on this knowledge, the use of EGCG could be of benefit in respiratory diseases with acute or chronic inflammatory, oxidative, and fibrotizing processes in their pathogenesis. This article reviews current information on the biological effects of EGCG in those respiratory diseases or animal models in which EGCG has been administered, i.e., acute respiratory distress syndrome, respiratory infections, COVID-19, bronchial asthma, chronic obstructive pulmonary disease, lung fibrosis, silicosis, lung cancer, pulmonary hypertension, and lung embolism, and critically discusses effectiveness of EGCG administration in these respiratory disorders. For this review, articles in English language from the PubMed database were used.

Photochemoprevention of ultraviolet Beam Radiation-induced DNA damage in keratinocytes by topical delivery of nanoformulated Epigallocatechin-3-gallate

Ultraviolet Beam (UVB) radiation is the main cause of skin cancer worldwide. Besides biocompatibility, the instability and limited skin permeability are the most challenging features of many effective photochemopreventive agents. (-)-Epigallocatechin-3-gallate (EGCG) is a natural polyphenolic compound extracted from Camellia sinensis that has been demonstrated to have antioxidant, anti-inflammatory, and anti-cancer properties. We evaluated the efficacy of three innovative EGCG nanoformulations in chemoprevention of UVB-induced DNA damage in keratinocytes. Results indicated that the EGCG nanoformulations reduced UVB-induced oxidative stress elevation and DNA damage. The nanoformulations also reduced the UVB-induced formation of pyrimidine and pyrimidone photoproducts in 2D human immortalized HaCaT keratinocytes and SKH-1 hairless mice through antioxidant effects and possibly through absorption of UVB radiation. In addition, EGCG nanoformulations inhibited UVB-induced chemokine/cytokine activation and promoted EGCG skin permeability and stability. Taken together, the results suggest the use of EGCG nanoformulations as potential natural chemopreventive agents during exposure to UVB radiation.

Enzymatic Synthesis and Antioxidant Activity of Mono- and Diacylated Epigallocatechin Gallate and Related By-Products

Ester derivatives of epigallocatechin gallate (EGCG) were enzymatically prepared by one-step transesterification with vinyl fatty acids consisting of varying acyl groups ranging from 2 to 18 carbon atoms (acetate, butyrate, caproate, caprylate, caprate, laurate, myristate, and stearate). The main acylation products were EGCG monoesters and diesters. However, due to the presence of trace amounts of water in the reaction medium, minor but noticeable hydrolysis of EGCG also occurred as a side reaction which required a prolonged purification process due to the formation of by-products such as gallic acid, epigallocatechin, and their esters. In this contribution, 8 EGCG monoesters, 7 EGCG diesters, and 7 gallic acid monoesters were isolated and purified, and the acylation positions were characterized. Meanwhile, several classical chemicals (DPPH, ABTS, FRAP, and Fe²⁺ chelation assays), food (β-carotene bleaching assay), and biological (LDL and DNA oxidation assays) models were conducted to evaluate and systematically compare their antioxidant efficacy. The lipophilicity of the EGCG derivatives increased with the increasing chain length of the acyl group and led to the fluctuation of their antioxidant efficacies. Three main factors, namely, the reduction potential, the partition coefficient of solute in the solvent system, and the steric hindrance of antioxidant agent and related substrates were considered to help explain the biased antioxidant performance of EGCG derivatives upon acylation modification. The results strongly suggest that the acylated EGCGs have great potential as lipophilic alternatives to the water-soluble EGCG in lipid-based matrices.

Modification of flavonoids: methods and influences on biological activities

Flavonoids are important active ingredients in plant-based food, which have many beneficial effects on health. But the low solubility, poor oral bioavailability, and inferior stability of many flavonoids may limit their applications in the food, cosmetics, and pharmaceutical industries. Structural modification can overcome these shortcomings to improve and extend the application of flavonoids. The study of how to modify flavonoids and the influence of various modifications on biological activity have drawn great interest in the current literature. In this review, the working principles and operating conditions of modification methods were summarized along with their potential and limitations in terms of operational safety, cost, and productivity. The influence of various modifications on biological activities and the structure-activity relationships of flavonoids derivatives were discussed and highlighted, which may give guidance for the synthesis of highly effective active agents. In addition, the safety of flavonoids derivatives is reviewed, and future research directions of flavonoid modification research are discussed.

Effects of Tea Polyphenol Palmitate Existing in the Oil Phase on the Stability of Myofibrillar Protein O/W Emulsion

This study aimed to explore the effect of adding different concentrations (0, 0.01%, 0.03%, and 0.05% (w/w)) of tea polyphenol palmitate (TPP) in the oil phase on the emulsifying properties of 5 and 10 mg/mL myofibrillar protein (MP). Particle size results revealed that the flocculation of droplets increased as TPP concentration increased and that droplets in 5 mg/mL MP emulsions (25−34 μm) were larger than in 10 mg/mL MP emulsions (14−22 μm). The emulsifying activity index of 5 mg/mL MP emulsions decreased with increasing TPP concentration. The micrographs showed that the droplets of MP emulsions exhibited extensive flocculation at TPP concentrations >0.03%. Compared with 5 mg/mL MP emulsions, 10 mg/mL MP emulsions showed better physical stability and reduced flocculation degree, which coincided with lower delta backscattering intensity (ΔBS) and Turbiscan stability index values. The flow properties of emulsions can be successfully depicted by Ostwald−de Waele models (R2 > 0.99). The concentrations of TPP and protein affect the K values of emulsions (p < 0.05). Altogether, increased protein concentration in the continuous phase could improve emulsion stability by increasing viscosity, offsetting the adverse effects of TPP to a certain extent. This study is expected to promote the rational application of TPP in protein emulsion products of high quality and acceptability.

Chemico-biological aspects of (-)-epigallocatechin-3-gallate (EGCG) to improve its stability, bioavailability and membrane permeability: Current status and future prospects

Natural products have been a bedrock for drug discovery for decades. (-)-Epigallocatechin-3-gallate (EGCG) is one of the widely studied natural polyphenolic compounds derived from green tea. It is the key component believed to be responsible for the medicinal value of green tea. Significant studies implemented in in vitro, in cellulo, and in vivo models have suggested its anti-oxidant, anti-cancer, anti-diabetic, anti-inflammatory, anti-microbial, neuroprotective activities etc. Despite having such a wide array of therapeutic potential and promising results in preclinical studies, its applicability to humans has encountered with rather limited success largely due to the poor bioavailability, poor membrane permeability, rapid metabolic clearance and lack of stability of EGCG. Therefore, novel techniques are warranted to address those limitations so that EGCG or its modified analogs can be used in the clinical setup. This review comprehensively covers different strategies such as structural modifications, nano-carriers as efficient drug delivery systems, synergistic studies with other bioactivities to improve the chemico-biological aspects (e.g., stability, bioavailability, permeability, etc.) of EGCG for its enhanced pharmacokinetics and pharmacological properties, eventually enhancing its therapeutic potentials. We think this review article will serve as a strong platform with comprehensive literature on the development of novel techniques to improve the bioavailability of EGCG so that it can be translated to the clinical applications.

Epigallocatechin gallate: Phytochemistry, bioavailability, utilization challenges, and strategies

Epigallocatechin gallate (EGCG), a green tea catechin, has gained the attention of current study due to its excellent health-promoting effects. It possesses anti-obesity, antimicrobial, anticancer, anti-inflammatory activities, and is under extensive investigation in functional foods for improvement. It is susceptible to lower stability, lesser bioavailability, and lower absorption rate due to various environmental, processing, formulations, and gastrointestinal conditions of the human body. Therefore, it is the foremost concern for the researchers to enhance its bioactivity and make it the most suitable therapeutic compound for its clinical applications. In the current review, factors affecting the bioavailability of EGCG and the possible strategies to overcome these issues are reviewed and discussed. This review summarizes structural modifications and delivery through nanoparticle-based approaches including nano-emulsions, encapsulations, and silica-based nanoparticles for effective use of EGCG in functional foods. Moreover, recent advances to enhance EGCG therapeutic efficacy by specifically targeting its molecules to increase its bioavailability and stability are also described. PRACTICAL APPLICATIONS: The main green tea constituent EGCG possesses several health-promoting effects making EGCG a potential therapeutic compound to cure ailments. However, its low stability and bioavailability render its uses in many disorders. Synthesizing EGCG prodrugs by structural modifications helps against its low bioavailability and stability by overcoming premature degradation and lower absorption rate. This review paper summarizes various strategies that benefit EGCG under different physiological conditions. The esterification, nanoparticle approaches, silica-based EGCG-NPs, and EGCG formulations serve as ideal EGCG modification strategies to deliver superior concentrations with lesser toxicity for its efficient penetration and absorption across cells both in vitro and in vivo. As a result of EGCG modifications, its bioactivities would be highly improved at lower doses. The protected or modified EGCG molecule would have enhanced potential effects and stability that would contribute to the clinical applications and expand its use in various food and cosmetic industries.

Epigallocatechin gallate (EGCG) attenuates myocardial hypertrophy and fibrosis induced by transverse aortic constriction via inhibiting the Akt/mTOR pathway

CONTEXT

Epigallocatechin gallate (EGCG) is the most abundant catechin from tea. Previous studies have indicated EGCG has a cardioprotective effect.

OBJECTIVE

This manuscript mainly explores the role of EGCG in pressure-overload cardiac hypertrophy and its mechanism related to the Akt/mTOR pathway.

METHODS AND METHODS

Transverse aortic constriction (TAC) was utilized to establish the cardiac hypertrophy mice model. C57BL/6 mice were assigned into 6 groups. Starting from the first day after surgery, mice received different doses of EGCG (20, 40, 80 mg/kg) or vehicle orally for four weeks. Heart weight to body weight (HW/BW) ratio and heart weight to tibia length (HW/TL) ratio as well as hematoxylin-eosin staining were utilized to evaluate cardiac hypertrophy. Masson's trichrome and Sirius red staining were used to depict cardiac fibrosis. The expressions of fibrosis and hypertrophy-related markers and Akt/mTOR pathway were quantified by western blot and qRT-PCR.

RESULTS

EGCG significantly attenuated cardiac function shown by decreased HW/BW (TAC, 6.82 ± 0.44 vs. 20 mg/kg EGCG, 5.53 ± 0.45; 40 mg/kg EGCG, 4.79 ± 0.32; 80 mg/kg EGCG, 4.81 ± 0.38) and HW/TL (TAC, 11.94 ± 0.69 vs. 20 mg/kg EGCG, 11.44 ± 0.49; 40 mg/kg EGCG, 8.83 ± 0.58; 80 mg/kg EGCG, 8.98 ± 0.63) ratios as well as alleviated cardiac histology. After treatment, hemodynamics was improved, cardiac fibrosis was attenuated. The activated Akt/mTOR pathway was inhibited by EGCG.

DISCUSSION AND CONCLUSIONS

EGCG plays a protective role in the TAC model by regulating the Akt/mTOR pathway, which provides a theoretical basis for its clinical treatment.

Role of Epigallocatechin Gallate in Glucose, Lipid, and Protein Metabolism and L-Theanine in the Metabolism-Regulatory Effects of Epigallocatechin Gallate

Epigallocatechin gallate (EGCG) and L-theanine (LTA) are important bioactive components in tea that have shown promising effects on nutrient metabolism. However, whether EGCG alone or combined with LTA can regulate the glucose, lipid, and protein metabolism of healthy rats remains unclear. Therefore, we treated healthy rats with EGCG or the combination of EGCG and LTA (EGCG+LTA) to investigate the effects of EGCG on nutrient metabolism and the role of LTA in the metabolism-regulatory effects of EGCG. The results showed that compared with the control group, EGCG activated insulin and AMP-activated protein kinase (AMPK) signals, thus regulating glucose, lipid, and protein metabolism. Compared with EGCG, EGCG+LTA enhanced hepatic and muscle glycogen levels and suppressed phosphorylation of AMPK, glycogen synthase 2, mammalian target of rapamycin, and ribosomal protein S6 kinase. In addition, EGCG+LTA inhibited the expression of liver kinase B1, insulin receptor and insulin receptor substrate, and promoted the phosphorylation level of acetyl-CoA carboxylase. Furthermore, both EGCG and EGCG+LTA were harmless for young rats. In conclusion, EGCG activated AMPK and insulin pathways, thereby promoting glycolysis, glycogen, and protein synthesis and inhibiting fatty acid (FA) and cholesterol synthesis. However, LTA cooperated with EGCG to promote glycogen metabolism and suppressed the effect EGCG on FA and protein synthesis via AMPK signals.

Effect of carbon chain length on the hydrolysis and transport characteristics of alkyl gallates in rat intestine

Phenolipids such as alkyl gallates (A-GAs) have been approved by food industry as non-toxic antioxidant additives. However, their digestion and absorption mechanisms in the intestine have not yet been clarified. In this research, the hydrolysis and transport characteristics of A-GAs with fatty alcohols of various chain lengths (C1:0, C2:0, C3:0, C4:0, C8:0, C12:0 and C16:0) were estimated by the everted-rat-gut-sac model (ERGSM) for the first time. High-performance liquid chromatography measurements proved that measurable peaks corresponding to methyl gallate (G-C1:0), ethyl gallate (G-C2:0), propyl gallate (G-C3:0) and butyl gallate (G-C4:0) were discovered in the serosal fluids, which showed the short-chain alkyl gallates can cross the membrane in the form of esters. Besides, all A-GAs were hydrolyzed to GA in the mucosal solution, which contributed evidently to the transport of GA across the membrane of the small intestine. Meanwhile, the hydrolysis rate of A-GAs and transport rate of GA initially increased and then decreased with the chain length, exhibiting a maximum for octyl gallate (G-C8:0). In general, all A-GAs have the behavior of sustained-release. In consequence, the production of A-GAs should be an effective method to extend action time and further increases biological activities of GA.

EGCG Alleviates Oxidative Stress and Inhibits Aflatoxin B1 Biosynthesis via MAPK Signaling Pathway

Aflatoxin biosynthesis has established a connection with oxidative stress, suggesting a prevention strategy for aflatoxin contamination via reactive oxygen species (ROS) removal. Epigallocatechin gallate (EGCG) is one of the most active and the richest molecules in green tea with well-known antioxidant effects. Here, we found EGCG could inhibit aflatoxin B1 (AFB1) biosynthesis without affecting mycelial growth in Aspergillus flavus, and the arrest occurred before the synthesis of toxin intermediate metabolites. Further RNA-seq analysis indicated that multiple genes involved in AFB1 biosynthesis were down-regulated. In addition, EGCG exposure facilitated the significantly decreased expression of AtfA which is a bZIP (basic leucine zipper) transcription factor mediating oxidative stress. Notably, KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis indicated that the MAPK signaling pathway target transcription factor was down-regulated by 1 mg/mL EGCG. Further Western blot analysis showed 1 mg/mL EGCG could decrease the levels of phosphorylated SakA in both the cytoplasm and nucleus. Taken together, these data evidently supported that EGCG inhibited AFB1 biosynthesis and alleviated oxidative stress via MAPK signaling pathway. Finally, we evaluated AFB1 contamination in soy sauce fermentation and found that EGCG could completely control AFB1 contamination at 8 mg/mL. Conclusively, our results supported the potential use of EGCG as a natural agent to prevent AFB1 contamination in fermentation industry.

Treatment of lymphomas via regulating the Signal transduction pathways by natural therapeutic approaches: A review

Lymphoma is a heterogeneous group of malignancies, which comprises 4.2 % of all new cancer cases and 3.3 % of all cancer deaths in 2019, globally. The dysregulation of immune system, certain bacterial or viral infections, autoimmune diseases, and immune suppression are associated with a high risk of lymphoma. Although several conventional strategies have improved during the past few decades, but their detrimental impacts remain an obstacle to be resolved. However, natural compounds are considered a good option in the treatment of lymphomas because of their easy accessibility, specific mode of action, high biodegradability, and cost-effectiveness. Vegetables, fruits, and beverages are the primary sources of natural active compounds. The present review investigated the activities of different natural medicinal compounds including curcumin, MK615, resveratrol, bromelain, EGCG, and Annonaceous acetogenins to treat lymphomas. Moreover, in vitro and in vivo studies, classification, risk factors, and diagnosis of lymphoma are also discussed in the present review. The accumulated data proposed that natural compounds regulate the signaling pathways at the level of cell proliferation, apoptosis, and cell cycle to exhibit anti-lymphoma activities both in-vivo and in-vitro studies and suggested that these active compounds could be a good therapeutic option in the treatment of different types of lymphomas.