In vitro Cytotoxicity of Epigallocatechin Gallate and Tea Extracts to Cancerous and Normal Cells from the Human Oral Cavity

Pilot-Scale Screening of Clinically Approved Drugs to Identify Uridine Insertion/Deletion RNA Editing Inhibitors in Trypanosoma brucei

RNA editing pathway is a validated target in kinetoplastid parasites (Trypanosoma brucei, Trypanosoma cruzi, and Leishmania spp.) that cause severe diseases in humans and livestock. An essential large protein complex, the editosome, mediates uridine insertion and deletion in RNA editing through a stepwise process. This study details the discovery of editosome inhibitors by screening a library of widely used human drugs using our previously developed in vitro biochemical Ribozyme Insertion Deletion Editing (RIDE) assay. Subsequent studies on the mode of action of the identified hits and hit expansion efforts unveiled compounds that interfere with RNA-editosome interactions and novel ligase inhibitors with IC50 values in the low micromolar range. Docking studies on the ligase demonstrated similar binding characteristics for ATP and our novel epigallocatechin gallate inhibitor. The inhibitors demonstrated potent trypanocidal activity and are promising candidates for drug repurposing due to their lack of cytotoxic effects. Further studies are necessary to validate these targets using more definitive gene-editing techniques and to enhance the safety profile.

Biocompatible and nondegradable microcapsules using an ethylamine-bridged EGCG dimer for successful therapeutic cell transplantation

Conventional alginate microcapsules are widely used for encapsulating therapeutic cells to reduce the host immune response. However, the exchange of monovalent cations with divalent cations for crosslinking can lead to a sol-gel phase transition, resulting in gradual degradation and swelling of the microcapsules in the body. To address this limitation, we present a biocompatible and nondegradable epigallocatechin-3-gallate (EGCG)-based microencapsulation with ethylamine-bridged EGCG dimers (EGCG(d)), denoted as 'Epi-Capsules'. These Epi-Capsules showed increased physical properties and Ca2+ chelating resistance compared to conventional alginate microcapsules. Horseradish peroxidase (HRP) treatment is very effective in increasing the stability of Epi-Capsule((+)HRP) due to the crosslinking between EGCG(d) molecules. Interestingly, the Epi-Capsules(oxi) using a pre-oxidized EGCG(d) can support long-term survival (>90 days) of xenotransplanted insulin-secreting islets in diabetic mice in vivo, which is attributed to its structural stability and reactive oxygen species (ROS) scavenging for lower fibrotic activity. Collectively, this EGCG-based microencapsulation can create Ca2+ chelating-resistance and anti-oxidant activity, which could be a promising strategy for cell therapies for diabetes and other diseases.

Superoxide Dismutase-Mimetic Polyphenol-Based Carbon Dots for Multimodal Bioimaging and Treatment of Atopic Dermatitis

Polyphenols have been investigated for their potential to mitigate inflammation in the context of atopic dermatitis (AD). In this study, epigallocatechin-3-gallate (EGCG)-based carbon dots (EGCG@CDs) were developed to enhance transdermal penetration, reduce inflammation, recapitulate superoxide dismutase (SOD) activity, and provide antimicrobial effects for AD treatment. The water-soluble EGCG@CDs in a few nanometers size exhibit a negative zeta potential, making them suitable for effective transdermal penetration. The fluorescence properties, including an upconversion effect, make EGCG@CDs suitable imaging probes for both in vitro and in vivo applications. By mimicking the SOD enzyme, EGCG@CDs scavenge reactive oxygen species (ROS) and actively produce hydrogen peroxide through a highly catalytic capability toward the oxygen reduction reaction, resulting in the inhibition of bacterial growth. The enhanced antioxidant properties, high charge mobility, and various functional groups of EGCG@CDs prove effective in reducing intracellular ROS in an in vitro AD model. In the mouse AD model, EGCG@CDs incorporated into a hydrogel actively penetrated the epidermal layer, leading to ROS scavenging, reduced mast cell activation, and histological recovery of skin barriers. This research represents the versatile potential of EGCG@CDs in addressing AD and advancing tissue engineering.

Polyphenols and Their Impact on the Prevention of Neurodegenerative Diseases and Development

It is well known that neurodegenerative diseases' development and progression are accelerated due to oxidative stress and inflammation, which result in impairment of mitochondrial function, cellular damage, and dysfunction of DNA repair systems. The increased consumption of antioxidants can postpone the development of these disorders and improve the quality of patients' lives who have already been diagnosed with neurodegenerative diseases. Prolonging life span in developed countries contributes to an increase in the incidence ratio of chronic age-related neurodegenerative disorders, such as PD (Parkinson's disease), AD (Alzheimer's disease), or numerous forms of age-related dementias. Dietary supplementation with neuroprotective plant-derived polyphenols might be considered an important element of healthy aging. Some polyphenols improve cognition, mood, visual functions, language, and verbal memory functions. Polyphenols bioavailability differs greatly from one compound to another and is determined by solubility, degree of polymerization, conjugation, or glycosylation resulting from chemical structure. It is still unclear which polyphenols are beneficial because their potential depends on efficient transport across the BBB (blood-brain barrier), bioavailability, and stability in the CNS (central nervous system). Polyphenols improve brain functions by having a direct impact on cells and processes in the CNS. For a direct effect, polyphenolic compounds must be able to overcome the BBB and accumulate in brain tissue. In this review, the latest achievements in studies (animal models and clinical trials) on the effect of polyphenols on brain activity and function are described. The beneficial impact of plant polyphenols on the brain may be summarized by their role in increasing brain plasticity and related cognition improvement. As reversible MAO (monoamine oxidase) inhibitors, polyphenols are mood modulators and improve neuronal self-being through an increase in dopamine, serotonin, and noradrenaline amounts in the brain tissue. After analyzing the prohealth effects of various eating patterns, it was postulated that their beneficial effects result from synergistic interactions between individual dietary components. Polyphenols act on the brain endothelial cells and improve the BBB's integrity and reduce inflammation, thus protecting the brain from additional injury during stroke or autoimmune diseases. Polyphenolic compounds are capable of lowering blood pressure and improving cerebral blood flow. Many studies have revealed that a nutritional model based on increased consumption of antioxidants has the potential to ameliorate the cognitive impairment associated with neurodegenerative disorders. Randomized clinical trials have also shown that the improvement of cognitive functions resulting from the consumption of foods rich in flavonoids is independent of age and health conditions. For therapeutic use, sufficient quantities of polyphenols must cross the BBB and reach the brain tissue in active form. An important issue in the direct action of polyphenols on the CNS is not only their penetration through the BBB, but also their brain metabolism and localization. The bioavailability of polyphenols is low. The most usual oral administration also conflicts with bioavailability. The main factors that limit this process and have an effect on therapeutic efficacy are: selective permeability across BBB, gastrointestinal transformations, poor absorption, rapid hepatic and colonic metabolism, and systemic elimination. Thus, phenolic compounds have inadequate bioavailability for human applications to have any beneficial effects. In recent years, new strategies have been attempted in order to exert cognitive benefits and neuroprotective effects. Converting polyphenols into nanostructures is one of the theories proposed to enhance their bioavailability. The following nanoscale delivery systems can be used to encapsulate polyphenols: nanocapsules, nanospheres, micelles, cyclodextrins, solid lipid nanoparticles, and liposomes. It results in great expectations for the wide-scale and effective use of polyphenols in the prevention of neurodegenerative diseases. Thus far, only natural polyphenols have been studied as neuroprotectors. Perhaps some modification of the chemical structure of a given polyphenol may increase its neuroprotective activity and transportation through the BBB. However, numerous questions should be answered before developing neuroprotective medications based on plant polyphenols.

Possible Mechanism of Dysphania ambrosioides (L.) Mosyakin & Clemants Seed Extract Suppresses the Migration and Invasion of Human Hepatocellular Carcinoma Cells SMMC-7721

Mexican tea (Dysphania ambrosioides (L.) Mosyakin & Clemants) is rich in phenolic acids and flavonoids and could be a potential medicinal herb that can be used for prevention of human hepatocellular carcinoma. The objective of this study was to elaborate the possible mechanism for the prevention or treatment of hepatocellular carcinoma using Mexican tea, and to provide new avenues for the utilization of the invasive plant. In this study, the D. ambrosioides seed extracts (CSE) were analyzed by gas chromatography-mass spectrometry, and the effects of CSE on proliferation, migration, invasion, and gene expression of SMMC-7721 cells were investigated. Eight compounds were identified in CSE, and the compound with the highest content was ascaridole (25.82 %). The proliferation was significantly inhibited by CSE (p<0.05), and IC50 values were 0.587 g/L, 0.360 g/L, and 0.361 g/L at 24 h, 36 h, and 48 h, respectively. Migration and invasion were significantly inhibited (p<0.05). The network pharmacology and transcriptome analysis indicated that 2-hydroxy-2,6,6-trimethylbicyclo[3.1.1]heptan-3-one, cis-11-eicosenoic acid and 2-ethylcyclohexanone might be the active compounds. Transcriptome analysis indicated that the Wnt signaling pathway, which is related to migration and invasion, was significantly altered; this was verified by western blot assay. The expression of wnt11, lef1 and mmp7 genes in SMMC-7721 cells was significantly down-regulated (p<0.05), while gsk-3β was significantly up-regulated (p<0.05). These results indicate that CSE inhibits the invasion and migration of SMMC-7721 cells in hepatocellular carcinoma through the Wnt signaling pathway.

Effect of Chicken Egg White-Derived Peptide and Hydrolysates on Abnormal Skin Pigmentation during Wound Recovery

Abnormal skin pigmentation commonly occurs during the wound healing process due to the overproduction of melanin. Chicken egg white (CEW) has long been used to improve skin health. Previous published works had found CEW proteins house bioactive peptides that inhibit tyrosinase, the key enzyme of melanogenesis. The current study aimed to evaluate the anti-pigmentation potential and mechanism of the CEW-derived peptide (GYSLGNWVCAAK) and hydrolysates (CEWH_mono and CEWH_di), using a cell-based model. All of these peptide and hydrolysates inhibited intracellular tyrosinase activity and melanin level up to 45.39 ± 1.31 and 70.01 ± 1.00%, respectively. GYSLGNWVCAAK and CEWH_di reduced intracellular cAMP levels by 13.38 ± 3.65 and 14.55 ± 2.82%, respectively; however, CEWH_mono did not affect cAMP level. Moreover, the hydrolysates downregulated the mRNA expression of melanogenesis-related genes, such as Mitf, Tyr, Trp-1 and Trp-2, but GYSLGNWVCAAK only suppressed Tyr gene expression. Downregulation of the genes may lower the catalytic activities and/or affect the structural stability of TYR, TRP-1 and TRP-2; thus, impeding melanogenesis to cause an anti-pigmentation effect in the cell. Outcomes from the current study could serve as the starting point to understand the underlying complex, multifaceted melanogenesis regulatory mechanism at the cellular level.

Exploring Epigallocatechin-3-Gallate Autoxidation Products: Specific Incubation Times Required for Emergence of Anti-Amyloid Properties

Amyloidogenic protein/peptide aggregation into fibrillar aggregates is associated with multiple amyloidoses, including widespread neurodegenerative disorders. Despite years of research and a well-understood mechanism, there are still very few treatments available for the increasing number of amyloid-related disorders. In recent years, the search for potential anti-aggregation compounds has shifted toward naturally occurring molecules, with one of the most promising being epigallocatechin-3-gallate (EGCG). This polyphenolic compound was shown to inhibit the aggregation of several amyloidogenic proteins/peptides, including amyloid-beta (related to Alzheimer’s disease) and alpha-synuclein (related to Parkinson’s disease). However, multiple reports have indicated its limited stability under physiological conditions and the possibility of EGCG autoxidation products being the actual inhibitory compounds. In this work, we explore how different EGCG autoxidation products associate with non-aggregated insulin, as well as how they affect its aggregation and resulting fibril structure. We also show that there is a specific incubation time required for the emergence of compounds, which alters the amyloid aggregation process.

Sambucus nigra flower and berry extracts for food and therapeutic applications: effect of gastrointestinal digestion on in vitro and in vivo bioactivity and toxicity

The bioavailability of natural compounds should be assessed through different perspectives. Studying the behaviour of the extracts after digestion is often overlooked but is crucial for success in the development of active food ingredients. Thus, the bioaccessibility of S. nigra (flower and berry) extracts after in vitro gastrointestinal digestion and their effect on toxicity and bioactive potential were studied. The flower extract had a higher content of phenolic compounds, like rutin, chlorogenic acid and rosmarinic acid, while in the berry extract, rutin, resveratrol, ferulic acid and chlorogenic acid were the main phenolic compounds. The effect of the non-digested and digested extracts was significantly different on different cell lines. The IC₅₀ of the normal cell line (L929) was the highest, indicating low toxicity. The IC₅₀ of the cancerous cell lines (HeLa and HT29) was lower, particularly the extract obtained from the flower upon digestion. In the presence of an oxidant agent - tbHP, only the berry extract was able to significantly reduce the formation of ROS in the L929 cell line, while in the HeLa cells, all the extracts were able to reduce ROS formation. The in vivo Artemia salina lethality bioassay demonstrated a dose-dependent effect of extracts, and the berry digested extract induced the lowest mortality rate. The promising results obtained on the chemical and biological evaluation of the extracts indicate that the natural compounds isolated from S. nigra by-products can be used as potential ingredients for functional food formulations and/or as bio-therapeutic agents.

Green tea catechins inhibit Porphyromonas gulae LPS-induced inflammatory responses in human gingival epithelial cells: Running title

OBJECTIVES

To determine the anti-inflammatory effects of green tea catechins in immortalized human gingival epithelial cells (Ca9-22) stimulated with Porphyromonas gulae lipopolysaccharide (LPS).

METHODS

Ca9-22 cells were incubated with P. gulae LPS (10 μg/ml) with or without green tea catechins, epigallocatechin-3-gallate (EGCg), epigallocatechin (EGC), epicatechin-3-gallate (ECG), and epicatechin (EC) (each at 50 μM), for 6 or 24 hours. Real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay were used to determine the induction of cyclooxygenase 2 (COX2), tumor necrosis factor alpha (TNF-ɑ), interleukin 6 (IL-6), and IL-8. Furthermore, the expression of toll-like receptors (TLRs) 2 and 4 was examined using real-time PCR and western blotting analysis, and phosphorylation of the p38 and ERK1/2 was examined using western blotting analysis.

RESULTS

At the mRNA and protein levels, EGCg, EGC, ECG, and EC were found to significantly inhibit COX2, TNF-ɑ, IL-6, and IL-8. Furthermore, the levels of ERK1/2 and p38 phosphorylation induced by P. gulae LPS were decreased following the addition of each of the catechins, as well as TLR2 and 4 mRNA and protein.

CONCLUSIONS

These findings indicate that green tea catechins are potent inhibitors of inflammatory responses induced by P. gulae LPS, and may also be useful for prevention and/or attenuation of periodontitis.

Epigallocatechin-3-Gallate Delivery in Lipid-Based Nanoparticles: Potentiality and Perspectives for Future Applications in Cancer Chemoprevention and Therapy

Chemoprevention is a strategy aimed to not only reduce the risk but also delay the development or recurrence of cancer. An ideal chemopreventive agent is not dangerous and ought not to result in side effects or damage to human health. In this context, epigallocatechin-3-gallate (EGCG) is considered a suitable chemopreventive agent, but its clinical use is limited by many factors, namely, the difference in source, administration, individual metabolism, absorption, and distribution. Genetic and dietary differences greatly cause this variability, which has limited the rational use of EGCG in chemoprevention and, particularly, the definition of a safe and efficient concentration. In the present mini review, the main limitations to a complete understanding of the use of EGCG as a chemopreventive agent will be briefly illustrated. This review also indicates the introduction and trialing of lipid-based nanoparticles (NPs) as a proper strategy to deliver EGCG at a well-defined concentration for better investigation of the chemopreventive activity. Finally, some examples of cancers that might benefit from EGCG treatment in different stages of the disease are proposed.

Synthesis, Anticancer Assessment, and Molecular Docking of Novel Chalcone-Thienopyrimidine Derivatives in HepG2 and MCF-7 Cell Lines

Heterocycles containing thienopyrimidine moieties have attracted attention due to their interesting biological and pharmacological activities. In this research article, we reported the synthesis of a series of new hybrid molecules through merging the structural features of chalcones and pyridothienopyrimidinones. Our results indicated that the synthesis of chalcone-thienopyrimidine derivatives from the corresponding thienopyrimidine and chalcones proceeded in a relatively short reaction time with good yields and high purity. Most of these novel compounds exhibited moderate to robust cytotoxicity against HepG2 and MCF-7 cancer cells similar to that of 5-fluorouracil (5-FU). The results indicated that IC₅₀ of the two compounds (3b and 3g) showed more potent anticancer activities against HepG2 and MCF-7 than 5-FU. An MTT assay and flow cytometry showed that only 3b and 3g had anticancer activity and antiproliferative activities at the G1 phase against MCF-7 cells, while six compounds (3a-e and 3g) had cytotoxicity and cell cycle arrest at different phases against HepG2 cells. Their cytotoxicity was achieved through downregulation of Bcl-2 and upregulation of Bax, caspase-3, and caspase-9. Although all tested compounds increased oxidative stress via increment of MDA levels and decrement of glutathione reductase (GR) activities compared to control, the 3a, 3b, and 3g in HepG2 and 3b and 3g in MCF-7 achieved the target results. Moreover, there was a positive correlation between cytotoxic efficacy of the compound and apoptosis in both HepG2 (R ² = 0.531; P = 0.001) and MCF-7 (R ² = 0.219; P = 0.349) cell lines. The results of molecular docking analysis of 3a-g into the binding groove of Bcl-2 revealed relatively moderate binding free energies compared to the selective Bcl-2 inhibitor, DRO. Like venetoclax, compounds 3a-g showed 2 violations from Lipinski's rule. However, the results of the ADME study also revealed higher drug-likeness scores for compounds 3a-g than for venetoclax. In conclusion, the tested newly synthesized chalcone-pyridothienopyrimidinone derivatives showed promising antiproliferative and apoptotic effects. Mechanistically, the compounds increased ROS production with concomitant cell cycle arrest and apoptosis. Therefore, regulation of the cell cycle and apoptosis are possible targets for anticancer therapy. The tested compounds could be potent anticancer agents to be tested in future clinical trials after extensive pharmacodynamic, pharmacokinetic, and toxicity profile investigations.

Antibacterial, antioxidant and anti-inflammatory PLCL/gelatin nanofiber membranes to promote wound healing

Epigallocatechin-3-O-gallate (EGCG) is a green biomedical agent for promoting wound healing, which possess excellent antibacterial, antioxidant and anti-inflammatory activities. For improving the low bioavailability challenges of EGCG in vivo, we had successful created a low-cost and simple wound dressing Poly (L-Lactic-co-caprolactone) (PLCL)/Gelatin/EGCG/Core-shell nanofiber membrane (PGEC) with drug sustained release capacity through coaxial electrospinning technology. In vitro experimental indicated that the core-shell structure wound dressing had excellent biocompatibility, antibacterial and antioxidant ability, which could support cell viability and proliferation, encourage re-epithelialization during the healing process, inhibit subsequent wound infection and thus promote wound regeneration. In vivo experimental demonstrated that PGEC wound dressing could promote wound healing, the histological results further demonstrated that PGEC not only facilitated early wound closure but also influenced cellular differentiation and tissue organization. Meanwhile, PGEC had excellent hemostatic ability. Taken all together, we believed that the PGEC wound dressing, which could localize delivery of EGCG, had high potential clinical application for promoting wound healing, hemostasis or other related clinical applications in the future.

Effect of epigallocatechin-3-gallate on tumor necrosis factor-alpha production by human gingival fibroblasts stimulated with bacterial lipopolysaccharide: An in vitro study

Background:

Evidence shows that epigallocatechin-3-gallate (EGCG) in green tea has anti-inflammatory effects.

Aim:

This study assessed the effect of EGCG on the production of tumor necrosis factor-alpha (TNF-α) as an inflammatory cytokine in periodontitis, which produced by human gingival fibroblasts (HGFs) stimulated with lipopolysaccharide (LPS) of Porphyromonas gingivalis.

Materials and Methods:

In this study, HGFs were cultured and subjected to LPS and EGCG. Cell viability of different concentrations of EGCG (10, 25, 50, 75, and 100 μM) and LPS (1, 10, 20, and 50 μg/mL) was assessed using methyl-thiazole-tetrazolium (MTT) assay. Then, the best concentrations of EGCG and P. gingivalis LPS were used simultaneously and separately to assess the production of TNF-α by HGFs using the enzyme-linked immunosorbent assay (ELISA). Assessments were done at 1, 3, and 5 days. Data were read using the ELISA reader and analyzed by the SPSS through two-way ANOVA.

Results:

LPS at 1, 10, and 20 and EGCG at 10.25 and 50 μM showed the least cytotoxicity in MTT assay. ELISA showed EGCG alone decreased the production of TNF-α in all days, except 10 μM on day 1. 1, 10, and 20 μg/mL LPS increased the output of TNF-α on days 1 and 3 while reducing it on day 5. The combination of EGCG and LPS showed a decrease of TNF-α in all days except on day 5 that revealed an increase in the production of TNF-α at 25 and 50 μM EGCG.

Conclusion:

In the combination use of EGCG and LPS, EGCG shows anti-inflammatory effects by decreasing the production of TNF-α by HGFs stimulated with P. gingivalis.

Use of leptin-conjugated phosphatidic acid liposomes with resveratrol and epigallocatechin gallate to protect dopaminergic neurons against apoptosis for Parkinson's disease therapy

Complex liposomes were assembled with 1,2-distearoyl-sn-glycero-3-phosphocholine, dihexadecyl phosphate (DHDP), cholesterol and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphate (PA) to act as drug carriers for resveratrol (RES) and epigallocatechin gallate (EGCG). The liposomes were modified with leptin (Lep) on the surface to cross the blood-brain barrier (BBB) and to rescue degenerated dopaminergic neurons. The activity of RES and EGCG against neurotoxicity was investigated using an in vitro neurodegenerative model established by SH-SY5Y cells with an insult of 1-methyl-4-phenylpyridinium (MPP⁺). The results indicated that increasing the mole percentage of DHDP and PA increased the particle size and absolute zeta potential value, and improved the entrapment efficiency of RES and EGCG; however, this increase reduced the release rate of RES and EGCG and the grafting efficiency of Lep. The ability of Lep/RES-EGCG-PA-liposomes to cross the BBB was found to be higher than that of non-modified liposomes. Further, the addition of PA and Lep into liposomes enhanced cell viability and target efficiency. The immunofluorescence results demonstrated that the conjugation of Lep with liposomes enabled the docking of HBMECs and SH-SY5Y cells via Lep receptor, and enhanced their ability to permeate the BBB and cellular uptake. Immunofluorescence and western blot analysis also revealed that RES and EGCG encapsulated into liposomes could be a neural defensive strategy by reducing the apoptosis promotor protein Bcl-2 associated X protein and α-synuclein, and enhancement in the apoptosis inhibitor protein B cell lymphoma 2, tyrosine hydroxylase, and the dopamine transporter. Hence, Lep-PA-liposomes can be an excellent choice of potential delivery system for PD treatment.

AG-9, an Elastin-Derived Peptide, Increases In Vitro Oral Tongue Carcinoma Cell Invasion, through an Increase in MMP-2 Secretion and MT1-MMP Expression, in a RPSA-Dependent Manner

Oral tongue squamous cell carcinoma is one of the most prevalent head and neck cancers. During tumor progression, elastin fragments are released in the tumor microenvironment. Among them, we previously identified a nonapeptide, AG-9, that stimulates melanoma progression in vivo in a mouse melanoma model. In the present paper, we studied AG-9 effect on tongue squamous cell carcinoma invasive properties. We demonstrated that AG-9 stimulates cell invasion in vitro in a modified Boyen chamber model. It increases MMP-2 secretion, analyzed by zymography and MT1-MMP expression, studied by Western blot. The stimulatory effect was mediated through Ribosomal Protein SA (RPSA) receptor binding as demonstrated by SiRNA experiments. The green tea-derived polyphenol, (−)-epigallocatechin-3-gallate (EGCG), was previously shown to bind RPSA. Molecular docking experiments were performed to compare the preferred areas of interaction of AG-9 and EGCG with RPSA and suggested overlapping areas. This was confirmed by competition assays. EGCG abolished AG-9-induced invasion, MMP-2 secretion, and MT1-MMP expression.

Bioengineering Approaches to Accelerate Clinical Translation of Stem Cell Therapies Treating Osteochondral Diseases

The osteochondral tissue is an interface between articular cartilage and bone. The diverse composition, mechanical properties, and cell phenotype in these two tissues pose a big challenge for the reconstruction of the defected interface. Due to the availability and inherent regenerative therapeutic properties, stem cells provide tremendous promise to repair osteochondral defect. This review is aimed at highlighting recent progress in utilizing bioengineering approaches to improve stem cell therapies for osteochondral diseases, which include microgel encapsulation, adhesive bioinks, and bioprinting to control the administration and distribution. We will also explore utilizing synthetic biology tools to control the differentiation fate and deliver therapeutic biomolecules to modulate the immune response. Finally, future directions and opportunities in the development of more potent and predictable stem cell therapies for osteochondral repair are discussed.

Modulatory influences of antiviral bioactive compounds on cell viability, mRNA and protein expression of cytochrome P450 3A4 and P-glycoprotein in HepG2 and HEK293 cells

The induction of cytochrome P450 3A4 (CYP3A4) and P-glycoprotein (ABCB1) influence drug plasma, and eventually decreases the drugs' therapeutic effects. The effects of Plant-derived compounds (PCs) on drug-metabolising proteins are largely unknown. This study investigated the cytotoxicity, cell viability profiles and regulatory influences of four PCs (epigallocatechin gallate (EGCG), kaempferol-7-glucoside (K7G), luteolin (LUT) and ellagic acid (EGA)) on the mRNA and protein expressions of CYP3A4 and ABCB1 in HepG2 and HEK293 cells. After treatment with the PCs (0-400 µM) for 24 h, 80% (IC₂₀) and 50% (IC₅₀) cell viability were determined. The PCs were not toxic to HepG2 (ATP levels increased at IC₂₀, insignificant change in LDH (lactate dehydrogenase) with the exception of LUT, and ABCB1 protein expressions decreased. The PCs decreased CYP3A4 at IC₂₀ (except LUT), EGCG and K7G at IC₂₀ decreased mRNA expression. For HEK293 cells, no significant change in ATP, except for EGCG IC₂₀ and K7G IC₅₀ which decreased and increased, respectively. LDH decreased at IC₂₀, but LUT IC₅₀ significant increase LDH. ABCB1 protein expression increased at both IC₂₀ and IC₅₀, but LUT and EGA at IC₅₀ decreased mRNA expression. The PCs at IC_20, and IC₅₀ of LUT, K7G and of EGCG may enhance drug bioavailability.

Epigallocatechin-3-gallate mobilizes intracellular Ca2+ in prostate cancer cells through combined Ca2+ entry and Ca2+-induced Ca2+ release

AIMS

To elucidate the mechanism by which (-)-epigallocatechin-3-gallate (EGCG) mediates intracellular Ca²⁺ increase in androgen-independent prostate cancer (PCa) cells.

MAIN METHODS

Following exposure to different doses of EGCG, viability of DU145 and PC3 PCa cells was evaluated by MTT assay and the intracellular Ca²⁺ dynamics by the fluorescent Ca²⁺ chelator Fura-2. The expression of different channels was investigated by qPCR analysis and sulfhydryl bonds by Ellman's assay.

KEY FINDINGS

EGCG inhibited DU145 and PC3 proliferation with IC₅₀ = 46 and 56 μM, respectively, and induced dose-dependent peaks of internal Ca²⁺ that were dependent on extracellular Ca²⁺. The expression of TRPC4 and TRPC6 channels was revealed by qPCR in PC3 cells, but lack of effect by modulators and blockers ruled out an exclusive role for these, as well as for voltage-dependent T-type Ca²⁺ channels. Application of dithiothreitol and catalase and sulfhydryl (SH) measurements showed that EGCG-induced Ca²⁺ rise depends on SH oxidation, while the effect of EGTA, dantrolene, and the PLC inhibitor U73122 suggested that EGCG-induced Ca²⁺ influx acts as a trigger for Ca²⁺-induced Ca²⁺ release, involving both ryanodine and IP₃ receptors. Different from EGCG, ATP caused a rapid Ca²⁺ increase, which was independent of external Ca²⁺, but sensitive to U73122.

SIGNIFICANCE

EGCG induces an internal Ca²⁺ increase in PCa cells by a multi-step mechanism. As dysregulation of cytosolic Ca²⁺ is directly linked to apoptosis in PCa cells, these data confirm the possibility of using EGCG as a synergistic adjuvant in combined therapies for recalcitrant malignancies like androgen-independent PCa.

Antiviral Natural Products for Arbovirus Infections

Over the course of the last 50 years, the emergence of several arboviruses have resulted in countless outbreaks globally. With a high proportion of infections occurring in tropical and subtropical regions where arthropods tend to be abundant, Asia in particular is a region that is heavily affected by arboviral diseases caused by dengue, Japanese encephalitis, West Nile, Zika, and chikungunya viruses. Major gaps in protection against the most significant emerging arboviruses remains as there are currently no antivirals available, and vaccines are only available for some. A potential source of antiviral compounds could be discovered in natural products—such as vegetables, fruits, flowers, herbal plants, marine organisms and microorganisms—from which various compounds have been documented to exhibit antiviral activities and are expected to have good tolerability and minimal side effects. Polyphenols and plant extracts have been extensively studied for their antiviral properties against arboviruses and have demonstrated promising results. With an abundance of natural products to screen for new antiviral compounds, it is highly optimistic that natural products will continue to play an important role in contributing to antiviral drug development and in reducing the global infection burden of arboviruses.

Antiproliferative Effect of Acridine Chalcone Is Mediated by Induction of Oxidative Stress

Chalcones are naturally occurring phytochemicals with diverse biological activities including antioxidant, antiproliferative, and anticancer effects. Some studies indicate that the antiproliferative effect of chalcones may be associated with their pro-oxidant effect. In the present study, we evaluated contribution of oxidative stress in the antiproliferative effect of acridine chalcone 1C ((2 E)-3-(acridin-9-yl)-1-(2,6-dimethoxyphenyl)prop-2-en-1-one) in human colorectal HCT116 cells. We demonstrated that chalcone 1C induced oxidative stress via increased reactive oxygen/nitrogen species (ROS/RNS) and superoxide production with a simultaneous weak adaptive activation of the cellular antioxidant defence mechanism. Furthermore, we also showed chalcone-induced mitochondrial dysfunction, DNA damage, and apoptosis induction. Moreover, activation of mitogen activated phosphokinase (MAPK) signalling pathway in 1C-treated cancer cells was also observed. On the other hand, co-treatment of cells with strong antioxidant, N-acetyl cysteine (NAC), significantly attenuated all of the above-mentioned effects of chalcone 1C, that is, decreased oxidant production, prevent mitochondrial dysfunction, DNA damage, and induction of apoptosis, as well as partially preventing the activation of MAPK signalling. Taken together, we documented the role of ROS in the antiproliferative/pro-apoptotic effects of acridine chalcone 1C. Moreover, these data suggest that this chalcone may be useful as a promising anti-cancer agent for treating colon cancer.

Optimization of Catechin and Proanthocyanidin Recovery from Grape Seeds Using Microwave-Assisted Extraction

Grape seed extract (GSE) is a rich source of condensed flavonoid tannins, also called proanthocyanidins (PACs). The high molecular weight of polymeric PAC limits their biological activity due to poor bioavailability. The present study was undertaken to explore the potential applicability of microwave-assisted extraction (MAE) to convert GSE-PAC into monomeric catechins. A central composite design (CCD) was used to optimize the processing conditions for the MAE. The maximum total yield of monomeric catechins (catechin, epicatechin, and epicatechin gallate) and PAC were 8.2 mg/g dry weight (DW) and 56.4 mg catechin equivalence (CE)/g DW, respectively. The optimized MAE condition was 94% ethanol, 170 °C temperature, and a duration of 55 min. Compared to the results for PACs extracted via conventional extraction (Con) (94% ethanol; shaking at 25 °C for 55 min), MAE yielded 3.9-fold more monomeric catechins and 5.5-fold more PACs. The MAE showed higher antioxidant capacity and α-glucosidase inhibitory activity than that of the conventional extract, suggesting the potential use of the MAE products of grape seeds as a functional food ingredient and nutraceutical.

Effects of flavonoids on tongue squamous cell carcinoma

Squamous cell carcinoma (SCC) of the tongue is associated with tobacco use, alcohol abuse, and human papillomavirus (HPV) infections. While clinical outcomes have recently improved for HPV-positive patients in general, 50% of patients suffering from tongue cancer die within 5 years of being diagnosed. Flavonoids are secondary plant metabolites with a wide range of biological activities including antioxidant, anti-inflammatory, and anticancer activities. Flavonoids have generated high interest as therapeutic agents owing to their low toxicity and their effects on a large variety of cancer cell types. In this literature review, we evaluate the actions of flavonoids on SCC of the tongue demonstrated in both in vivo and in vitro models.

Thickness-Tunable Eggshell Membrane Hydrolysate Nanocoating with Enhanced Cytocompatibility and Neurite Outgrowth

The eggshell membrane is one of the easily obtainable natural biomaterials, but has been neglected in the biomaterial community, compared with marine biomaterials and discarded as a food waste. In this work, we utilized the ESM hydrolysate (ESMH), which was obtained by the enzymochemical method, as a bioactive functional material for interfacial bioengineering, exemplified by thickness-tunable, layer-by-layer (LbL) nanocoating with the Fe(III)-tannic acid (TA) complex. [Fe(III)-TA/ESMH] LbL films, ending with the ESMH layer, showed great cytocompatiblility with HeLa cells and even primary hippocampal neuron cells. More importantly, the films were found to be neurochemically active, inducing the acceleration of neurite outgrowth for the long-term neuron culture. We believe that the ability for building cytocompatible ESMH films in a thickness-tunable manner would be applicable to a broad range of different nanomaterials in shape and size and would be utilized with multimodal functionalities for biomedical applications, such as bioencapsulation, theranostics, and regenerative medicine.

Gallol-derived ECM-mimetic adhesive bioinks exhibiting temporal shear-thinning and stabilization behavior

3D bioprinting is an attractive technique to fabricate well-organized, cell-laden constructs for tissue repair and disease modeling. Although numerous hydrogel bioinks have been developed, materials are still needed that mimic the cellular microenvironment, have the appropriate viscosity and stabilization for printing, and are cytocompatible. Here, we present a unique gallol-modified extracellular matrix (ECM) hydrogel ink that is inspired by rapid fruit browning phenomena. The gallol-modification of ECM components (e.g., hyaluronic acid, gelatin) allowed (i) immediate gelation and shear-thinning properties by dynamic hydrogen bonds on short time-scales and (ii) further auto-oxidation and covalent crosslinking for stabilization on longer time-scales. The gallol ECM hydrogel ink was printable using an extrusion-based 3D printer by exploiting temporal shear-thinning properties, and further showed cytocompatibility (∼95% viability) and on-tissue printability due to adhesiveness of gallol moieties. Printed cell-laden filaments degraded and swelled with culture over 6 days, corresponding to increases in cell density and spreading. Ultimately, this strategy is useful for designing hydrogel inks with tunable properties for 3D bioprinting. STATEMENT OF SIGNIFICANCE: 3D bioprinting is a promising technique for the fabrication of cell-laden constructs for applications as in vitro models or for therapeutic applications. Despite the previous development of numerous hydrogel bioinks, there still remain challenging considerations in the design of bioinks. In this study, we present a unique cytocompatible hydrogel ink with gallol modification that is inspired by rapid fruit browning phenomena. The gallol hydrogel ink has three important properties: i) it shows immediate gelation by dynamic, reversible bonds for shear-thinning extrusion, ii) it allows spontaneous stabilization by subsequent covalent crosslinking after printing, and iii) it is printable on tissues by adhesive properties of gallol moieties. As such, this work presents a new approach in the design of hydrogel inks.

Enhancing skin penetration of epigallocatechin gallate by modifying partition coefficient using reverse micelle method

Aim: (-)-Epigallocatechin gallate (EGCG) has been reported as inducing apoptosis in cervical cancer. However, EGCG demonstrates low skin permeability. In order to develop topical delivery of EGCG, the partition coefficient, log P, was modified using a reverse micelle method. Results & methodology: During this study, Tween 80 and Span 80 were added to EGCG at hydrophilic-lipophilic balance (HLB) values of 4.3, 6 and 8. The results showed that lowering the HLB value increases the log P value of EGCG and results in higher IC₅₀ values in Henrietta Lacks (HeLa) cancer cells than that of EGCG. Surfactant-modified EGCG-HLB 6 produced faster and deeper skin penetration than EGCG. Conclusion: Modification of log P value using a combination of Tween 80 and Span 80 improved cytotoxicity and topical delivery of EGCG.

Palliative Role of Aqueous Ginger Extract on N-Nitroso-N-Methylurea-Induced Gastric Cancer

Ginger (Zingiber officinale) is a spice and also an herbal medicine used worldwide for managing GI tract disturbances. However, its role in gastric cancer is sparingly known. This study ensures the standardization of gastric cancer by the induction of N-nitroso N-methyl Urea (MNU) and to determine the role of the aqueous extract of ginger (AGE) in MNU-induced gastric cancer in albino Wistar rats. Accordingly, the anticancer potential of AGE and its possible mode of action were assessed on rats exposed to MNU, by various biochemical and molecular assays. As evidenced by the extent of lipid peroxidation, gastrin levels and histopathological sections in MNU-induced cancerous lesions at 8 wk which was stabilized at 16 wk confirming the induction of gastric carcinoma by the chemical carcinogen. Further, results revealed that AGE alleviated the oxidative stress as evidenced by the stomach antioxidant enzymes (SOD, catalase, GPx, and GR), markers of oxidative stress (TRx, GRx) and Gastrin, a specific marker for gastric cancer and a decreased level of pro-inflammatory markers (NF-kB, TNF-α, IL-6, PGE2) which was further confirmed by histopathological analysis. AGE is responsible to mitigate oxidative stress and inflammation related to gastric cancer and could be used as a potential dietary intervention in gastric cancer therapy.

Influence of epigallocatechin-3-gallate in promoting proliferation and osteogenic differentiation of human periodontal ligament cells

BACKGROUND

Epigallocatechin-3-gallate (EGCG) was recently proposed to have the potential to regulate bone metabolism, however, its influence on osteogenesis remains controversial. The present study aimed to investigate the effects of EGCG on the proliferation and osteogenesis of human periodontal ligament cells (hPDLCs).

METHODS

Cells were cultured in osteogenic medium and treated with EGCG at various concentrations. Cell proliferation was analyzed using a CCK-8 assay and acridine orange (AO)/ethidium bromide (EB) staining. Flow cytometry was used to measure the intracellular reactive oxygen species (ROS) potential of hPDLCs. The expression levels of osteogenic marker genes and proteins in hPDLCs, including type I collagen (COL1), runt-related transcription factor 2 (RUNX2), osteopontin (OPN), and osterix (OSX), were determined by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analysis. In addition, alkaline phosphatase (ALP) activity was monitored both quantitatively and qualitatively. Extracellular matrix mineralization was further analyzed by alizarin red S staining.

RESULTS

The results showed that EGCG concentrations from 6 to 10 μM increased the ROS level and inhibited the cell proliferation of hPDLCs. EGCG concentrations from 2 to 8 μM effectively increased extracellular matrix mineralization, in which 4 and 6 μM EGCG generated the most mineralizing nodules. The ALP activity and the mRNA and protein expression levels of the tested osteogenic markers were most strongly up-regulated by treatment with 4 and 6 μM EGCG.

CONCLUSIONS

The present study demonstrated that EGCG might promote the osteogenesis of hPDLCs in a dose-dependent manner, with concentrations of 4 and 6 μM EGCG showing the strongest osteogenic enhancement without cytotoxicity, indicating a promising role for EGCG in periodontal regeneration in patients with deficient alveolar bone in the future.

Surface tethering of stem cells with H2O2-responsive anti-oxidizing colloidal particles for protection against oxidation-induced death

Mesenchymal stem cells are the new generation of medicine for treating numerous vascular diseases and tissue defects because of their ability to secrete therapeutic factors. Poor cellular survival in an oxidative diseased tissue, however, hinders the therapeutic efficacy. To this end, we hypothesized that tethering the surface of stem cells with colloidal particles capable of discharging antioxidant cargos in response to elevated levels of hydrogen peroxide (H₂O₂) would maintain survival and therapeutic activity of the stem cells. We examined this hypothesis by encapsulating epigallocatechin gallate (EGCG) and manganese oxide (MnO₂) nanocatalysts into particles comprising poly(d,l-lactide-co-glycolide)-block-hyaluronic acid. The MnO₂ nanocatalysts catalyzed the decomposition of H₂O₂ into oxygen gas, which increased the internal pressure of particles and accelerated the release of EGCG by 1.5-fold. Consequently, stem cells exhibited 1.2-fold higher metabolic activity and 2.8-fold higher secretion level of pro-angiogenic factor in sub-lethal H₂O₂ concentrations. These stem cells, in turn, performed a greater angiogenic potential with doubled number of newly formed mature blood vessels. We envisage that the results of this study will contribute to improving the therapeutic efficacy of a wide array of stem cells.

Epigallocatechin gallate in combination with eugenol or amarogentin shows synergistic chemotherapeutic potential in cervical cancer cell line

In this study, antitumor activity of epigallocatechin gallate (EGCG; major component of green tea polyphenol), eugenol (active component of clove), and amarogentin (active component of chirata plant) either alone or in combination were evaluated in Hela cell line. It was evident that EGCG with eugenol-amrogentin could highly inhibit the cellular proliferation and colony formation than individual treatments. Induction of apoptosis was also higher after treatment with EGCG in combination with eugenol-amrogentin than individual compound treatments. The antiproliferative effect of these compounds was due to downregulation of cyclinD1 and upregulation of cell cycle inhibitors LIMD1, RBSP3, and p16 at G1/S phase of cell cycle. Treatment of these compounds could induce promoter hypomethylation of LimD1 and P16 genes as a result of reduced expression of DNA methyltransferase 1 (DNMT1). Thus, our study indicated the better chemotherapeutic effect of EGCG in combination with eugenol-amarogentin in Hela cell line. The chemotherapeutic effect might be due to the epigenetic modification particularly DNA hypomethylation through downregulation of DNMT1.

Pyrimidine containing epidermal growth factor receptor kinase inhibitors: Synthesis and biological evaluation

Structure-based design and synthesis of pyrimidine containing reversible epidermal growth factor receptor (EGFR) inhibitors 1a-d are reported. The compounds (1a-d) inhibited the EGFR kinase activity in vitro with IC₅₀ range 740 nm to 3 μm. mRNA expression of EGFR downstream target genes, that is twist, c-fos and aurora were found to be altered upon treatment with compounds 1a-d. The compounds 1a-d exhibited excellent anticancer activity at low micromolar level (3.2-9 μm) in lung, colon and breast cancer cell lines. Furthermore, compounds induced the alteration in mitochondrial membrane potential and reactive oxygen species level and. Selected compound 1b was found to increase sub-G1 population indicative of cell death, the mode of cell death was apoptotic as evident from Annexin V verses propidium iodide assay. Molecular modelling further helped to investigate the binding recognition pattern of the compounds in ATP binding EGFR domain similar to erlotinib and dissimilar to WZ4002.

Isolation of a new resorcinolic lipid from Mangifera zeylanica Hook.f. bark and its cytotoxic and apoptotic potential

Mangifera zeylanica is a plant endemic to Sri Lanka and its bark has been used in traditional medicine to treat some cancers. This study was aimed to isolate potentially cytotoxic compound/s from the hexane extract of the bark of M. zeylanica by bio-activity guided fractionation. The structure of the isolated compound (1) was elucidated using ¹H, ¹³C NMR and mass spectrometric techniques. Compound 1 was identified as a new resorcinolic lipid (5-((8Z, 11Z, 14Z)-hexatriaconta-8, 11, 14-trienyl) benzene-1,3-diol). Apoptotic potential of the isolated compound was determined only in MCF-7 (estrogen receptor positive) breast cancer cells to which it was more cytotoxic than to normal mammary epithelial cells. Oxidative stress markers [reactive oxygen species (ROS), glutathione levels (GSH) and glutathione-S-transferase (GSH)] were also determined in MCF-7 cells treated with compound 1. Treatment with compound 1 led to an increase in caspase 7 activity, morphological features of apoptosis and DNA fragmentation in MCF-7 cells. Furthermore, it also led to an increase in ROS and GST levels while depleting GSH levels. Results of this study suggest that isolated new resorcinolic lipid can induce apoptosis in MCF-7 cells, possibly via oxidative stress mechanism.

Chemical basis for the disparate neuroprotective effects of the anthocyanins, callistephin and kuromanin, against nitrosative stress

Oxidative and nitrosative stress are major factors in neuronal cell death underlying neurodegenerative disease. Thus, supplementation of antioxidant defenses may be an effective therapeutic strategy for diseases such as amyotrophic lateral sclerosis, Parkinson's disease, and Alzheimer's disease. In this regard, treatment with nutraceutical antioxidants has garnered increasing attention; however, the differential neuroprotective effects of structurally similar nutraceuticals, which may affect their suitability as therapeutic agents, has not been directly examined. In this study we compare the ability of two anthocyanins, callistephin (pelargonidin-3-O-glucoside) and kuromanin (cyanidin-3-O-glucoside) to protect cerebellar granule neurons from damage induced by either oxidative or nitrosative stress. These anthocyanins differ by the presence of a single hydroxyl group on the B-ring of kuromanin, forming a catechol moiety. While both compounds protected neurons from oxidative stress induced by glutamate excitotoxicity, a stark contrast was observed under conditions of nitrosative stress. Only kuromanin displayed the capacity to defend neurons from nitric oxide (NO)-induced apoptosis. This protective effect was blocked by addition of Cu, Zn-superoxide dismutase, indicating that the neuroprotective mechanism is superoxide dependent. Based on these observations, we suggest a unique mechanism by which slight structural variances, specifically the absence or presence of a catechol moiety, lend kuromanin the unique ability to generate superoxide, which acts as a scavenger of NO. These findings indicate that kuromanin and compounds that share similar chemical characteristics may be more effective therapeutic agents for treating neurodegenerative diseases than callistephin and related (non-catechol) compounds.

The Antiproliferative Effect of Chakasaponins I and II, Floratheasaponin A, and Epigallocatechin 3-O-Gallate Isolated from Camellia sinensis on Human Digestive Tract Carcinoma Cell Lines

Acylated oleanane-type triterpene saponins, namely chakasaponins I (1) and II (2), floratheasaponin A (3), and their analogs, together with catechins—including (–)-epigallocatechin 3-O-gallate (4), flavonoids, and caffeine—have been isolated as characteristic functional constituents from the extracts of “tea flower”, the flower buds of Camellia sinensis (Theaceae), which have common components with that of the leaf part. These isolates exhibited antiproliferative activities against human digestive tract carcinoma HSC-2, HSC-4, MKN-45, and Caco-2 cells. The antiproliferative activities of the saponins (1–3, IC₅₀ = 4.4–14.1, 6.2–18.2, 4.5–17.3, and 19.3–40.6 µM, respectively) were more potent than those of catechins, flavonoids, and caffeine. To characterize the mechanisms of action of principal saponin constituents 1–3, a flow cytometric analysis using annexin-V/7-aminoactinomycin D (7-AAD) double staining in HSC-2 cells was performed. The percentage of apoptotic cells increased in a concentration-dependent manner. DNA fragmentation and caspase-3/7 activation were also detected after 48 h. These results suggested that antiproliferative activities of 1–3 induce apoptotic cell death via activation of caspase-3/7.

Transdermal solid delivery of epigallocatechin-3-gallate using self-double-emulsifying drug delivery system as vehicle: Formulation, evaluation and vesicle-skin interaction

The present study investigated a self-double-emulsifying drug delivery system loaded with epigallocatechin-3-gallate to improve epigallocatechin-3-gallate skin retention. The long chain solid lipids (cetostearyl alcohol) and macadamia oil were utilized as a carrier to deliver the bioactive ingredient. Response surface methodology was used to optimize the formulation, and the solid lipid to total lipid weight ratio, concentration of epigallocatechin-3-gallate and hydrophilic surfactant on skin retention were found to be the principal factors. The optimum formulation with high encapsulation efficiency (95.75%), self-double-emulsification performance (99.58%) and skin retention (87.24%) were derived from the fitted models and experimentally examined, demonstrating a reasonable agreement between experimental and predicted values. Epigallocatechin-3-gallate-self-double-emulsifying drug delivery system was found to be stable for 3 months. Transdermal studies could explain a higher skin diffusion of epigallocatechin-3-gallate from the self-double-emulsifying drug delivery system compared with EGCG aqueous solution. In vitro cytotoxicity showed that epigallocatechin-3-gallate-self-double-emulsifying drug delivery system did not exert hazardous effect on L929 cells up to 1:10.

Redox Modulations, Antioxidants, and Neuropsychiatric Disorders

Although antioxidants, redox modulations, and neuropsychiatric disorders have been widely studied for many years, the field would benefit from an integrative and corroborative review. Our primary objective is to delineate the biological significance of compounds that modulate our redox status (i.e., reactive species and antioxidants) as well as outline their current role in brain health and the impact of redox modulations on the severity of illnesses. Therefore, this review will not enter into the debate regarding the perceived medical legitimacy of antioxidants but rather seek to clarify their abilities and limitations. With this in mind, antioxidants may be interpreted as natural products with significant pharmacological actions in the body. A renewed understanding of these often overlooked compounds will allow us to critically appraise the current literature and provide an informed, novel perspective on an important healthcare issue. In this review, we will introduce the complex topics of redox modulations and their role in the development of select neuropsychiatric disorders.

Antioxidant potential, in vitro cytotoxicity and apoptotic effect induced by crude organic extract of Anthracophyllum lateritium against RD sarcoma cells

BACKGROUND

Macrofungi have an established history of use in traditional oriental medicine. Anthracophyllum lateritium is a terrestrial macrofungus found in the dry zone forest reserves in Sri Lanka. Yet there are no scientific reports on bioactive properties of this species. Hence, the current study was aimed at determining the antioxidant potential, in vitro antiproliferative activity and apoptotic effect induced by crude methanolic extract of A. lateritium against RD sarcoma cell line.

METHOD

The crude extract of A. lateritium was dissolved in methanol (MEFCA) and antioxidant activity was evaluated using in vitro assays: inhibition of DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging, ferric ion reducing power and 2-deoxy-D-ribose degradation assay. Total phenol and flavonoid contents of MEFCA were assayed using folin Ciocalteu method and aluminium chloride colorimetric method. In vitro cytotoxicity was determined using MTT assay against RD cells after 24 h exposure to MEFCA. Ethidium bromide/ acridine orange staining, DNA fragmentation and protein synthesis experiments were used to study the apoptotic features and antiproliferative activities of the treated cells. Glutathione assay and griess nitrite assay were used to analyze the reduced glutathione content and liberation of nitric oxide from apoptotic cells.

RESULTS

MEFCA showed promising antioxidant activity with EC50 values of 8.00 ± 0.35 μg/mL for DPPH scavenging and 83.33 ± 0.45 μg/mL for 2-deoxy-D-ribose degradation assay. The phenolic content was 265.15 ± 0.46 of (w/w) % of Gallic acid equivalents and flavonoid content was 173.01 ± 0.35 of (w/w) % of Epigallocatechingallate. A. lateritium showed strong in vitro cytotoxic activity with an EC50 of 18.80 ± 4.83 μg/mL for MTT assay against RD cells. Ethidium bromide/acridine orange staining and DNA fragmentation indicated the apoptotic features of treated cells. Protein levels showed a dose dependent decrease supporting the fact that A. lateritium induces apoptosis of treated cells. Glutathione content and nitric oxide content of cells exhibited a dose dependent increase suggesting the apoptosis of RD cells was mediated by both nitrie ions and nitric oxide.

CONCLUSIONS

The crude extract of the A. lateritium exhibited potent antioxidant, antiproliferative activity and apoptotic effect against RD cells providing supportive evidence for the ethnopharmacological use of this fungus in control of oxidative damage and remedy of cancer.

Effect of tannic acid, resveratrol and its derivatives, on oxidative damage and apoptosis in human neutrophils

In this study we compared the antioxidant and DNA protective activity of tannic acid and stilbene derivatives, resveratrol, 3,5,4(')-trimethoxystilbene (TMS) and pterostilbene in human neutrophils stimulated to oxidative burst by 12-O-tetradecanoyl-phorbol-13-acetate (TPA) in relation to apoptosis induction. All polyphenols within the concentration range 1-100 μM reduced the intracellular ROS and H2O2 production in the TPA-stimulated cells. Tannic acid was the most effective polyphenol in protection against DNA damage induced by TPA. In the resting neutrophils resveratrol and to lesser extent other polyphenols increased DNA damage and increased the level of p53. Pretreatment of the TPA-stimulated cells with tannic acid or stilbenes led to the induction of apoptosis. The most significant effect was observed as a result of treatment with TMS and resveratrol. These compounds appeared the most effective inducers of p53 in the TPA-challenged neutrophils, what may suggest that pro-apoptotic activity of these stilbenes might be related to p53 activation. Overall, the results of our present study demonstrate that tannic acid and stilbenes modulate the ROS production, ultimately leading to cell apoptosis in human neutrophils stimulated to oxidative burst. In resting neutrophils they exhibit pro-oxidant activity, which is accompanied by p53 induction.

Multifunctional T Lymphocytes Generated After Therapy With an Antitumor Gallotanin-Rich Normalized Fraction Are Related to Primary Tumor Size Reduction in a Breast Cancer Model

Natural compounds are promising sources for anticancer therapies because of their multifunctional activity and low toxicity. Although the host immune response (IR) is clearly implicated in tumor control, the relationship between natural therapies and IR has not yet been elucidated. The present work evaluates IR induction after treatment with a gallotannin-rich fraction from Caesalpinia spinosa (P2Et). Breast tumor 4T1 cells were used to evaluate antitumor properties and IR activation. Apoptosis and expression of immunogenic cell death (ICD) markers were assessed in vitro, whereas IR and postvaccination tumor evolution were assessed in vivo. P2Et fraction induced apoptotic cell death, displaying phosphatidylserine externalization and DNA fragmentation. ICD markers such as calreticulin, high-mobility group box 1 translocation from nuclei to cytoplasm, and ATP secretion were observed. Primary tumor control was improved by vaccination with P2Et-pretreated 4T1 cells (t-P2Et), yielding long-lasting ex vivo multifunctional CD4+ and CD8+ T lymphocytes (interleukin [IL]-2+, tumor necrosis factor [TNF]-α+, interferon [IFN]-γ+) that secrete IL-2, TNF-α, IL-4, IL-5, and IFN-γ after specific 4T1 cell stimulation. The present study constitutes the first demonstration of a long-lasting antitumor IR induction and primary tumor reduction induced by a complex natural fraction. These data reveal the potential use of this fraction as an adjuvant in breast cancer treatment.

Multifunctional T Lymphocytes Generated After Therapy With an Antitumor Gallotanin-Rich Normalized Fraction Are Related to Primary Tumor Size Reduction in a Breast Cancer Model

Natural compounds are promising sources for anticancer therapies because of their multifunctional activity and low toxicity. Although the host immune response (IR) is clearly implicated in tumor control, the relationship between natural therapies and IR has not yet been elucidated. The present work evaluates IR induction after treatment with a gallotannin-rich fraction from Caesalpinia spinosa (P2Et). Breast tumor 4T1 cells were used to evaluate antitumor properties and IR activation. Apoptosis and expression of immunogenic cell death (ICD) markers were assessed in vitro, whereas IR and postvaccination tumor evolution were assessed in vivo. P2Et fraction induced apoptotic cell death, displaying phosphatidylserine externalization and DNA fragmentation. ICD markers such as calreticulin, high-mobility group box 1 translocation from nuclei to cytoplasm, and ATP secretion were observed. Primary tumor control was improved by vaccination with P2Et-pretreated 4T1 cells (t-P2Et), yielding long-lasting ex vivo multifunctional CD4+ and CD8+ T lymphocytes (interleukin [IL]-2+, tumor necrosis factor [TNF]-α+, interferon [IFN]-γ+) that secrete IL-2, TNF-α, IL-4, IL-5, and IFN-γ after specific 4T1 cell stimulation. The present study constitutes the first demonstration of a long-lasting antitumor IR induction and primary tumor reduction induced by a complex natural fraction. These data reveal the potential use of this fraction as an adjuvant in breast cancer treatment.

Anticancer Activity of Saponins from Allium chinense against the B16 Melanoma and 4T1 Breast Carcinoma Cell

The cytotoxic substance of A. chinense saponins (ACSs) was isolated using ethanol extraction and purified with the D101 macroporous adsorption resin approach. We investigated the anticancer activity of ACSs in the B16 melanoma and 4T1 breast carcinoma cell lines. Methylthioninium chloride and hematoxylin-eosin staining with Giemsa dyestuff were used when the cells were treated with ACSs. The results showed that the cells morphologies changed significantly; ACSs induced cell death in B16 and 4T1 cells based on acridine orange/ethidium bromide double fluorescence staining, with the number and degree of apoptotic tumor cells increasing as ACS concentration increased. ACSs inhibited the proliferation of B16 and 4T1 cells in a dose-dependent manner. They also inhibited cell migration and colony formation and exhibited a concentration-dependent effect. In addition, ACSs apparently inhibited the growth of melanoma in vivo. The preliminary antitumor in vivo assay revealed that early medication positively affected tumor inhibition action and effectively protected the liver and spleen of C57 BL/6 mice from injury. This study provides evidence for the cytotoxicity of ACSs and a strong foundation for further research to establish the theoretical basis for cell death and help in the design and development of new anticancer drugs.

Natural products as photoprotection

The rise in solar ultraviolet radiation on the earth's surface has led to a depletion of stratospheric ozone over recent decades, thus accelerating the need to protect human skin against the harmful effects of UV radiation such as erythema, edema, hyperpigmentation, photoaging, and skin cancer. There are many different ways to protect skin against UV radiation's harmful effects. The most popular way to reduce the amount of UV radiation penetrating the skin is topical application of sunscreen products that contain UV absorbing or reflecting active molecules. Based on their protection mechanism, the active molecules in sunscreens are broadly divided into inorganic and organic agents. Inorganic sunscreens reflect and scatter UV and visible radiation, while organic sunscreens absorb UV radiation and then re-emit energy as heat or light. These synthetic molecules have limited concentration according to regulation concern. Several natural compounds with UV absorption property have been used to substitute for or to reduce the quantity of synthetic sunscreen agents. In addition to UV absorption property, most natural compounds were found to act as antioxidants, anti-inflammatory, and immunomodulatory agents, which provide further protection against the damaging effects of UV radiation exposure. Compounds derived from natural sources have gained considerable attention for use in sunscreen products and have bolstered the market trend toward natural cosmetics. This adds to the importance of there being a wide selection of active molecules in sunscreen formulations. This paper summarizes a number of natural products derived from propolis, plants, algae, and lichens that have shown potential photoprotection properties against UV radiation exposure-induced skin damage.

Involvement of the modulation of cancer cell redox status in the anti-tumoral effect of phenolic compounds

The association between the anti-tumoral properties of phenolics, the generation of ROS in culture medium and modulation of redox homeostasis was analyzed. In AGS cells, the anti-proliferative effect of quercetin was not reverted by catalase or SOD.