Mechanisms of action of green tea catechins, with a focus on ischemia-induced neurodegeneration

The ameliorative effect of rosmarinic acid and epigallocatechin gallate against doxorubicin-induced genotoxicity

Doxorubicin (Dox), an effective anticancer agent, is known for its genotoxic effects on normal cells. Phenolic compounds, renowned for their antitumor, antioxidant, and antigenotoxic properties, have gained prominence in recent years. This study investigates the individual and combined protective effects of rosmarinic acid (RA) and epigallocatechin gallate (EGCG) against Dox-induced genotoxicity using various in vitro test systems. The synergistic/antagonistic interaction of these combinations on Dox's chemotherapeutic effect is explored in breast cancer cell lines. Both RA and EGCG significantly mitigate Dox-induced genotoxicity in comet, micronucleus, and Ames assays. While Dox exhibits higher selectivity against MCF-7 cells, EGCG and RA show greater selectivity against MDA-MB-231 cells. The coefficient of drug interaction reveals a synergistic effect when RA or EGCG is combined with Dox in breast cancer cells. In conclusion, both EGCG and RA effectively reduce Dox-induced genetic damage and enhance Dox's cell viability-reducing effect in breast cancer cells.

Natural polyphenols for the management of autism spectrum disorder: a review of efficacy and molecular mechanisms

Natural polyphenols have been found to have some protective effects against neurodegenerative and neurodevelopmental disorders, which are attributed to a variety of biological properties, particularly antioxidant, immunomodulatory, and anti-inflammatory effects. Autism spectrum disorder is a complex neurological and neurodevelopmental disorder with no currently effective clinical treatment for its core symptoms. Regarding the management of autism spectrum disorder core symptoms, a number of experimental and clinical studies have been made using well-known dietary polyphenols with different effects and molecular mechanisms. The aim of this paper is to present the most effective natural polyphenols with the relevant molecular mechanisms in preclinical and clinical autism spectrum disorder studies.

Therapeutic potentialities of green tea (Camellia sinensis) in ischemic stroke: biochemical and molecular evidence

Ischemic stroke is a leading cause of disability and death in patients. Despite considerable recent advances in the treatment of ischemic stroke, only a limited number of effective neuroprotective agents are available for stroke. Green tea (Camellia sinensis) is a popular herbal plant, and numerous studies have indicated its health benefits for several diseases. Green tea is of interest due to its high content of catechin derivatives, including epicatechin, gallocatechin, epicatechin gallate, epigallocatechin, and epigallocatechin-3-gallate. This review tried to develop a feasible background for the potential effects of green tea and its bioactive derivatives concerning protection against ischemic stroke. Green tea's antioxidants, anti-inflammatory, anti-apoptotic, and neuroprotective effects are believed to be efficacious in stroke treatment. Evidence supports the idea that green tea can be used to assist in treating ischemic stroke.

Tannin complexation with metal ions and its implication on human health, environment and industry: An overview

Tannins, also known as plant polyphenols (PPs), are secondary metabolites widely existing in higher plants and are a kind of natural renewable resource with wide distribution, variety and quantity. Tannin has become an important class of fine chemicals due to the easily modified molecular structure and the properties of antibacterial and antioxidant, combining with protein and complexing with metal ion. Besides being used for tanning leather, tannins are also widely used in wood adhesive, concrete water-reducing agents, oil drilling fluid viscosity-reducing agents, pharmaceutical, mineral processing, water treatment, gas desulfurization, metal anticorrosion, wood anticorrosion, printing and dyeing, liquor clarification, oil antioxidant, daily chemical products and other products preparation. There are two groups of tannins: condensed tannins (CTs) (flavonoid-derived proanthocyanidins) and hydrolysable tannins (HTs) (gallic acid ester-derived). Tannins can form complexes with metals through the ortho-dihydroxyphenolic group(s), especially with transition metals. The structure-activity relationships, stoichiometry, and origin of the insolubility of which were emphasized. Furthermore, this paper proposed an in-depth discussion of the associations of tannins-metal complexes in human health, environment and industries.

Green Tea Catechins as Therapeutic Antioxidants for Glaucoma Treatment

Glaucoma is the leading cause of irreversible blindness and visual impairment, affecting more than 80 million individuals worldwide. Oxidative stress and inflammation-induced neurodegenerative insults to retinal ganglion cells are the main pathogenesis of glaucoma. Retinal ganglion cells, the retinal neurons transmitting the visual signals to the visual cortex in the brain, have very limited regeneration or recovery capacity after damages. Apart from intraocular pressure-lowering treatments, there is still no clinically effective treatment to rescue the degeneration of retinal ganglion cells in glaucoma. Dietary antioxidants are easily accessible and can be applied as supplements assisting in the clinical treatments. Catechins, a chemical family of flavonoids, are the phenolic compounds found in many plants, especially in green tea. The anti-oxidative and anti-inflammatory properties of green tea catechins in vitro and in vivo have been well proven. They could be a potential treatment ameliorating retinal ganglion cell degeneration in glaucoma. In this review, the chemistry, pharmacokinetics, and therapeutic properties of green tea catechins were summarized. Research updates on the biological effects of green tea catechins in cellular and animal experimental glaucoma models were reviewed. In addition, clinical potentials of green tea catechins for glaucoma treatment were also highlighted.

The effectiveness of anti-inflammatory agents in reducing chemotherapy-induced cognitive impairment in preclinical models - A systematic review

Chemotherapy-induced cognitive impairment (CICI) is a debilitating condition resulting from chemotherapy administration for cancer treatment. CICI is characterised by various cognitive impairments, including issues with learning, memory, and concentration, impacting quality of life. Several neural mechanisms are proposed to drive CICI, including inflammation, therefore, anti-inflammatory agents could ameliorate such impairments. Research is still in the preclinical stage; however, the efficacy of anti-inflammatories to reduce CICI in animal models is unknown. Therefore, a systematic review was conducted, with searches performed in PubMed, Scopus, Embase, PsycInfo and Cochrane Library. A total of 64 studies were included, and of the 50 agents identified, 41 (82%) reduced CICI. Interestingly, while non-traditional anti-inflammatory agents and natural compounds reduced impairment, the traditional agents were unsuccessful. Such results must be taken with caution due to the heterogeneity observed in terms of methods employed. Nevertheless, preliminary evidence suggests anti-inflammatory agents could be beneficial for treating CICI, although it may be critical to think beyond the use of traditional anti-inflammatories when considering which specific compounds to prioritise in development.

Epigenetics and the role of nutraceuticals in health and disease

In the post-genomic era, the data provided by complete genome sequencing could not answer several fundamental questions about the causes of many noninfectious diseases, diagnostic biomarkers, and novel therapeutic approaches. The rapidly expanding understanding of epigenetic mechanisms, as well as widespread acceptance of their hypothesized role in disease induction, facilitated the development of a number of novel diagnostic markers and therapeutic concepts. Epigenetic aberrations are reversible in nature, which enables the treatment of serious incurable diseases. Therefore, the interest in epigenetic modulatory effects has increased over the last decade, so about 60,000 publications discussing the expression of epigenetics could be detected in the PubMed database. Out of these, 58,442 were published alone in the last 10 years, including 17,672 reviews (69 historical articles), 314 clinical trials, 202 case reports, 197 meta-analyses, 156 letters to the editor, 108 randomized controlled trials, 87 observation studies, 40 book chapters, 22 published lectures, and 2 clinical trial protocols. The remaining publications are either miscellaneous or a mixture of the previously mentioned items. According to the species and gender, the publications included 44,589 human studies (17,106 females, 14,509 males, and the gender is not mentioned in the remaining papers) and 30,253 animal studies. In the present work, the role of epigenetic modulations in health and disease and the influencing factors in epigenetics are discussed.

The potential neuroprotective effects of stingless bee honey

Tropical Meliponini bees produce stingless bee honey (SBH). Studies have shown beneficial properties, including antibacterial, bacteriostatic, anti-inflammatory, neurotherapeutic, neuroprotective, wound, and sunburn healing capabilities. High phenolic acid and flavonoid concentrations offer SBH its benefits. SBH can include flavonoids, phenolic acids, ascorbic acid, tocopherol, organic acids, amino acids, and protein, depending on its botanical and geographic origins. Ursolic acid, p-coumaric acid, and gallic acid may diminish apoptotic signals in neuronal cells, such as nuclear morphological alterations and DNA fragmentation. Antioxidant activity minimizes reactive oxygen species (ROS) formation and lowers oxidative stress, inhibiting inflammation by decreasing enzymes generated during inflammation. Flavonoids in honey reduce neuroinflammation by decreasing proinflammatory cytokine and free radical production. Phytochemical components in honey, such as luteolin and phenylalanine, may aid neurological problems. A dietary amino acid, phenylalanine, may improve memory by functioning on brain-derived neurotrophic factor (BDNF) pathways. Neurotrophin BDNF binds to its major receptor, TrkB, and stimulates downstream signaling cascades, which are crucial for neurogenesis and synaptic plasticity. Through BDNF, SBH can stimulate synaptic plasticity and synaptogenesis, promoting learning and memory. Moreover, BDNF contributes to the adult brain's lasting structural and functional changes during limbic epileptogenesis by acting through the cognate receptor tyrosine receptor kinase B (TrkB). Given the higher antioxidants activity of SBH than the Apis sp. honey, it may be more therapeutically helpful. There is minimal research on SBH's neuroprotective effects, and the related pathways contribute to it is unclear. More research is needed to elucidate the underlying molecular process of SBH on BDNF/TrkB pathways in producing neuroprotective effects.

The Role and Mechanisms of Action of Catechins in Neurodegenerative Diseases

The prevalence, incidence and mortality rates of neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease are gradually increasing. New approaches are being developed to manage the progression and treatment of neurodegenerative diseases. Catechins, polyphenolic compounds, are key compounds that demonstrate therapeutic effects with their properties such as antioxidant, anti-inflammatory, anti-apoptotic properties in the prevention and treatment of neurodegenerative diseases. The therapeutic effects of catechins have been exhaustively studied in human and animal models. Catechins can have anti-inflammatory effects by suppressing inflammatory pathways and cytokines, as well as antioxidant effects such as chelating metal ions and scavenging radicals. They might reduce phosphorylation of tau proteins, aggregation of amyloid-beta and apoptotic proteins release. They can also decrease alpha-synuclein accumulation and increase dopamine levels. With all these effects, they can have an effect on neurodegenerative diseases. This review points to the potential mechanisms of catechins in neurodegenerative diseases, based on their findings in the literature review.Key teaching pointsCatechins can reduce amyloid-β plaque aggregation and tau phosphorylation.Catechins can decrease alfa-synuclein levels.Catechins can protect neuronal cells with their anti-apoptotic effect.More comprehensive studies are needed to clarify this issue.

Gaz Alafi: A Traditional Dessert in the Middle East With Anticancer, Immunomodulatory, and Antimicrobial Activities

Background

From the earliest times, manna has been widely used as a tasty local sweet or folk medicine. The type of manna being investigated in the present study is called Gaz-alafi, a mixture of insect and Quercus brantii leaves secretions from oak forests in the north of Iraq and west of Iran.

Methods

Aqueous and ethanol extracts were prepared as decoction. Various phytochemical tests were conducted to analyze manna composition, including total phenolic contents using the Folin-Ciocalteu method and LC-MS. Gallic acid and catechin were detected in both extracts, in addition to tiliroside presence in ethanol extract, which added more value to the phenolic content of ethanol extract. Cytotoxic activities of Gaz alafi were evaluated against breast cancer cell lines and compared to normal cell lines and doxorubicin using the MTT assay. Antimicrobial properties were assessed against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, and Candida albicans using the dilution method of the micro-titer plate. Serum levels of IFN-γ, interleukin-2 (IL-2), interleukin-4 (IL-4), and interleukin-10 (IL-10) were measured using ELISA. The effect of extracts on splenocyte proliferation was evaluated using the lymphocytes proliferation assay. Macrophage function was evaluated using the nitro blue tetrazolium assay, whereas pinocytosis was evaluated using the neutral red uptake assay. Ten days after tumor inoculation, changes in tumor size, survival rates, levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and creatinine were measured.

Results

The growth of cancer cells was inhibited by Gaz alafi ethanol extract. An alteration in IFN- γ, IL-2, and IL-4 levels toward antiproliferation immune response were reported for both extracts. The aqueous extract efficiently stimulated lymphocyte proliferation, phagocytosis, and pinocytosis, followed by the ethanol extracts with moderate activity. After treating the mice with ethanol extracts, a significant reduction in tumor size and several undetected tumors were recorded.

Conclusions

Gaz alafi extracts (aqueous and ethanol) are promising sources for anticancer and immunostimulatory agents. Further studies are needed to fully identify the chemical composition of Gaz alafi extracts.

The Impact of Supplements on Recovery After Peripheral Nerve Injury: A Review of the Literature

Peripheral nerve injury (PNI) can result from trauma, surgical resection, iatrogenic injury, and/or local anesthetic toxicity. Damage to peripheral nerves may result in debilitating weakness, numbness, paresthesia, pain, and/or autonomic instability. As PNI is associated with inflammation and nerve degeneration, means to mitigate this response could result in improved outcomes. Numerous nutrients have been investigated to prevent the negative sequelae of PNI. Alpha-lipoic acid, cytidine diphosphate-choline (CDP Choline), curcumin, melatonin, vitamin B12, and vitamin E have demonstrated notable success in improving recovery following PNI within animal models. While animal studies show ample evidence that various supplements may improve recovery after PNI, similar evidence in human patients is limited. The goal of this review is to analyze supplements that have been used successfully in animal models of PNI to serve as a reference for future studies on human patients. By analyzing supplements that have shown efficacy in animal studies, healthcare providers will have a resource from which to guide decision-making regarding future human studies investigating the role that supplements could play in PNI recovery. Ultimately, establishing a comprehensive understanding of these supplements in human patients following PNI may significantly improve post-surgical outcomes, quality of life, and peripheral nerve regeneration.

The Potential Benefits of Dietary Polyphenols for Peripheral Nerve Regeneration

Peripheral nerves are frequently affected by lesions caused by trauma (work accidents, car incidents, combat injuries) and following surgical procedures (for instance cancer resection), resulting in loss of motor and sensory function with lifelong impairments. Irrespective of the intrinsic capability of the peripheral nervous system for regeneration, spontaneous or surgically supported regeneration is often unsatisfactory with the limited functional success of nerve repair. For this reason, many efforts have been made to improve the regeneration process. Beyond innovative microsurgical methods that, in certain cases, are necessary to repair nerve injuries, different nonsurgical treatment approaches and adjunctive therapies have been investigated to enhance nerve regeneration. One possibility could be taking advantage of a healthy diet or lifestyle and their relation with proper body functions. Over the years, scientific evidence has been obtained on the benefits of the intake of polyphenols or polyphenol-rich foods in humans, highlighting the neuroprotective effects of these compounds in many neurodegenerative diseases. In order to improve the available knowledge about the potential beneficial role of polyphenols in the process of peripheral nerve regeneration, this review assessed the biological effects of polyphenol administration in supporting and promoting the regenerative process after peripheral nerve injury.

EGCG Promotes FUS Condensate Formation in a Methylation-Dependent Manner

Millions of people worldwide are affected by neurodegenerative diseases (NDs), and to date, no effective treatment has been reported. The hallmark of these diseases is the formation of pathological aggregates and fibrils in neural cells. Many studies have reported that catechins, polyphenolic compounds found in a variety of plants, can directly interact with amyloidogenic proteins, prevent the formation of toxic aggregates, and in turn play neuroprotective roles. Besides harboring amyloidogenic domains, several proteins involved in NDs possess arginine-glycine/arginine-glycine-glycine (RG/RGG) regions that contribute to the formation of protein condensates. Here, we aimed to assess whether epigallocatechin gallate (EGCG) can play a role in neuroprotection via direct interaction with such RG/RGG regions. We show that EGCG directly binds to the RG/RGG region of fused in sarcoma (FUS) and that arginine methylation enhances this interaction. Unexpectedly, we found that low micromolar amounts of EGCG were sufficient to restore RNA-dependent condensate formation of methylated FUS, whereas, in the absence of EGCG, no phase separation could be observed. Our data provide new mechanistic roles of EGCG in the regulation of phase separation of RG/RGG-containing proteins, which will promote understanding of the intricate function of EGCG in cells.

Powdered Green Tea (Matcha) Attenuates the Cognitive Dysfunction via the Regulation of Systemic Inflammation in Chronic PM2.5-Exposed BALB/c Mice

This study was conducted to evaluate the anti-amnesic effect of the aqueous extract of powdered green tea (matcha) (EM) in particulate matter (PM)_2.5-induced systemic inflammation in BALB/c mice. EM ameliorated spatial learning and memory function, short-term memory function, and long-term learning and memory function in PM_2.5-induced mice. EM protected against antioxidant deficit in pulmonary, dermal, and cerebral tissues. In addition, EM improved the cholinergic system through the regulation of acetylcholine (ACh) levels and acetylcholinesterase (AChE) activity in brain tissue, and it protected mitochondrial dysfunction by regulating the production of reactive oxygen species (ROS), mitochondrial membrane potential (MMP) and ATP contents in brain tissue. EM attenuated systemic inflammation and apoptotic signaling in pulmonary, dermal, olfactory bulb, and hippocampal tissues. Moreover, EM suppressed neuronal cytotoxicity and cholinergic dysfunction in hippocampal tissue. This study suggests that EM might be a potential substance to improve PM_2.5-induced cognitive dysfunction via the regulation of systemic inflammation.

Insight in the Recent Application of Polyphenols From Biomass

Biomass polyphenols are bio-active macromolecules with distinct chemical structures in a variety of biomass. In recent years, the study of biomass polyphenols and their application in food and medicine fields has become a research hotspot, which predominantly focuses on the preparation, purification, structural identifications, and measurements of biological activities. Many studies describe methodologies for extraction and application of polyphenols, but comprehensive work to review its physiological activities like drugs and health products are lacking. This paper comprehensively unlocks the bioactivities of antioxidant, antibacterial, antitumor, anticancer, neuroprotection, control of blood sugar, regulation of blood fat, and promotion of gastrointestinal health functions of polyphenols from different biomass sources. This review will serve as an illuminating resource for the global scientific community, especially for those who are actively working to promote the advances of the polyphenols research field.

Assessment of the neuroprotective effects of (-)-epigallocatechin-3-gallate on spinal cord ischemia-reperfusion injury in rats

Objective: Paraplegia or paraparesis due to spinal cord ischemia is one of the complications following thoracoabdominal aortic surgery. Recent studies revealed the neuroprotective effects of (-)-epigallocatechin-3-gallate (EGCG) on a variety of neurological disorders. The purpose of this study was to determine the neuroprotective effects of EGCG following spinal cord ischemia-reperfusion injury (IRI).Design: The present study was conducted on four groups of rats each as follows: Sham-operated group (laparotomy alone); Control group (with IRI); EGCGI group (50-mg/kg, i.p., before IRI), and EGCGII group (50-mg/kg, i.p., after IRI). Neurological function evaluated with motor deficit index (MDI) test. Spinal cord samples were taken 48 h after IRI and studied for determination of malodialdehyde (MDA) level, histopathology, and immunohistochemistry of caspase-3, TNF-α, and iNOS.Setting: Mazandaran University of Medical Sciences, Sari, Iran.Results: The level of MDA was significantly decreased in EGCG-treated rats. Attenuated caspase-3, TNF-α, and iNOS expression could be significantly detected in the EGCG-treated rats. Also, EGCG reduced the extent of degeneration of the spinal cord neurons, in addition to a significant reduction of MDI.Conclusion: The results suggest that pre- and post-treatment with EGCG may be effective in protecting spinal cord from IRI.

On the Development of a Cutaneous Flavonoid Delivery System: Advances and Limitations

Flavonoids are one of the vital classes of natural polyphenolic compounds abundantly found in plants. Due to their wide range of therapeutic properties, which include antioxidant, anti-inflammatory, photoprotective, and depigmentation effects, flavonoids have been demonstrated to be promising agents in the treatment of several skin disorders. However, their lipophilic nature and poor water solubility invariably lead to limited oral bioavailability. In addition, they are rapidly degraded and metabolized in the human body, hindering their potential contribution to the prevention and treatment of many disorders. Thus, to overcome these challenges, several cutaneous delivery systems have been extensively studied. Topical drug delivery besides offering an alternative administration route also ensures a sustained release of the active compound at the desired site of action. Incorporation into lipid or polymer-based nanoparticles appears to be a highly effective approach for cutaneous delivery of flavonoids with good encapsulation potential and reduced toxicity. This review focuses on currently available formulations used to administer either topically or systemically different classes of flavonoids in the skin, highlighting their potential application as therapeutic and preventive agents.

Therapeutic Effects of Catechins in Less Common Neurological and Neurodegenerative Disorders

In recent years, neurological and neurodegenerative disorders research has focused on altered molecular mechanisms in search of potential pharmacological targets, e.g., imbalances in mechanisms of response to oxidative stress, inflammation, apoptosis, autophagy, proliferation, differentiation, migration, and neuronal plasticity, which occur in less common neurological and neurodegenerative pathologies (Huntington disease, multiple sclerosis, fetal alcohol spectrum disorders, and Down syndrome). Here, we assess the effects of different catechins (particularly of epigalocatechin-3-gallate, EGCG) on these disorders, as well as their use in attenuating age-related cognitive decline in healthy individuals. Antioxidant and free radical scavenging properties of EGCG -due to their phenolic hydroxyl groups-, as well as its immunomodulatory, neuritogenic, and autophagic characteristics, makes this catechin a promising tool against neuroinflammation and microglia activation, common in these pathologies. Although EGCG promotes the inhibition of protein aggregation in experimental Huntington disease studies and improves the clinical severity in multiple sclerosis in animal models, its efficacy in humans remains controversial. EGCG may normalize DYRK1A (involved in neural plasticity) overproduction in Down syndrome, improving behavioral and neural phenotypes. In neurological pathologies caused by environmental agents, such as FASD, EGCG enhances antioxidant defense and regulates placental angiogenesis and neurodevelopmental processes. As demonstrated in animal models, catechins attenuate age-related cognitive decline, which results in improvements in long-term outcomes and working memory, reduction of hippocampal neuroinflammation, and enhancement of neuronal plasticity; however, further studies are needed. Catechins are valuable compounds for treating and preventing certain neurodegenerative and neurological diseases of genetic and environmental origin. However, the use of different doses of green tea extracts and EGCG makes it difficult to reach consistent conclusions for different populations.

On the therapeutic targets and pharmacological treatments for pain relief following spinal cord injury: A mechanistic review

Spinal cord injury (SCI) is globally considered as one of the most debilitating disorders, which interferes with daily activities and life of the affected patients. Despite many developments in related recognizing and treating procedures, post-SCI neuropathic pain (NP) is still a clinical challenge for clinicians with no distinct treatments. Accordingly, a comprehensive search was conducted in PubMed, Medline, Scopus, Web of Science, and national database (SID and Irandoc). The relevant articles regarding signaling pathways, therapeutic targets and pharmacotherapy of post-SCI pain were also reviewed. Data were collected with no time limitation until November 2020. The present study provides the findings on molecular mechanisms and therapeutic targets, as well as developing the critical signaling pathways to introduce novel neuroprotective treatments of post-SCI pain. From the pathophysiological mechanistic point of view, post-SCI inflammation activates the innate immune system, in which the immune cells elicit secondary injuries. So, targeting the critical signaling pathways for pain management in the SCI population has significant importance in providing new treatments. Indeed, several receptors, ion channels, excitatory neurotransmitters, enzymes, and key signaling pathways could be used as therapeutic targets, with a pivotal role of n-methyl-D-aspartate, gamma-aminobutyric acid, and inflammatory mediators. The current review focuses on conventional therapies, as well as crucial signaling pathways and promising therapeutic targets for post-SCI pain to provide new insights into the clinical treatment of post-SCI pain. The need to develop innovative delivery systems to treat SCI is also considered.

Medicinal plants and bioactive natural products as inhibitors of NLRP3 inflammasome

The NLR family, pyrin domain-containing 3 (NLRP3) inflammasome is a multiprotein complex that induces caspase-1 activation and the downstream substrates involved with the processing and secretion of the pro-inflammatory cytokines interleukin-1β (IL-1β) and IL-18 and tumor necrosis factor-α (TNF- α). The NLRP3 inflammasome is activated by a wide range of danger signals that derive from metabolic dysregulation. Activation of this complex often involves the adaptor ASC and upstream sensors including NLRP1, NLRP3, NLRC4, AIM2, and pyrin, which are activated by different stimuli including infectious agents and changes in cell homeostasis. It has been shown that nutraceuticals and medicinal plants have antiinflammatory properties and could be used as complementary therapy in the treatment of several chronic diseases that are related to inflammation, for example, cardiovascular diseases and diabetes mellitus. Herb-based medicine has demonstrated protective effects against NLRP3 inflammasome activation. Therefore, this review focuses on the effects of nutraceuticals and bioactive compounds derived from medicinal plants on NLRP3 inflammasome activation and the possible mechanisms of action of these natural products. Thus, herb-based, natural products/compounds can be considered novel, practical, and accessible agents in chronic inflammatory diseases by inhibiting NLRP3 inflammasome activation.

Clinical and pathological aspects of condyloma acuminatum - review of literature and case presentation

Condyloma acuminatum (CA) is a pathology caused by the human papillomavirus (HPV). It is manifested by the appearance of warts in the vulvar, pubic, and anorectal regions, but can occur in other areas. It is a common disease that can be prevented by using measures such as condoms or vaccine. Topical, local, pharmacological, surgical, and excisional therapy options are available for this pathology. Macroscopically, it appears as a vegetative tumor, with a single implantation base that branches towards the periphery, with a cauliflower appearance. CA is defined microscopically by acanthosis, parakeratosis, papillomatosis and koilocytosis. Immunohistochemical studies can detect the presence of various HPV strains or viral antigens and can emphasize certain specific characteristics; e.g., in the case presented in this study, we observed that the tumor had a fulminant evolution due to a strong vascular base identified with anti-cluster of differentiation (CD) 34 antibody, by the existence of epithelial cells with a high degree of cell proliferation, as evidenced by the anti-Ki67 antibody, the inactivation of the tumor suppressor gene and the appearance of immunolabeling for the anti-p53 antibody, by the strong immunoreactivity for p63 which reveals the existence of cells with dysplastic and neoplastic transformation potential, but also by detecting the immunolabeling for p16^INK4a that is associated with the existence of HPV. Also, the tumor was immunoreactive for cytokeratin (CK) AE1/AE3, partially immunoreactive for CK5/6 in the basal layer and negative for CK7, which demonstrates the squamous epithelial origin of the described tumor. Subepithelial cells of the inflammatory system have been identified, such as macrophages immunolabeled with anti-CD68 antibody, T-lymphocytes immunolabeled with anti-CD3 antibody and rare B-lymphocytes immunolabeled with anti-CD20 antibody, which demonstrates the strong cellular response to remove the virus from the structure. Surgical and excisional treatment was helpful for the patient, because she was able to resume normal sexual activity and defecation, and on the other hand, microscopic studies showed the potential for malignant transformation of CA.

Dietary Anti-Aging Polyphenols and Potential Mechanisms

For years, the consumption of a diet rich in fruits and vegetables has been considered healthy, increasing longevity, and decreasing morbidities. With the assistance of basic research investigating the potential mechanisms, it has become clear that the beneficial effects of plant-based foods are mainly due to the large amount of bioactive phenolic compounds contained. Indeed, substantial dietary intervention studies in humans have supported that the supplementation of polyphenols have various health-promoting effects, especially in the elderly population. In vitro examinations on the anti-aging mechanisms of polyphenols have been widely performed, using different types of natural and synthetic phenolic compounds. The aim of this review is to critically evaluate the experimental evidence demonstrating the beneficial effects of polyphenols on aging-related diseases. We highlight the potential anti-aging mechanisms of polyphenols, including antioxidant signaling, preventing cellular senescence, targeting microRNA, influencing NO bioavailability, and promoting mitochondrial function. While the trends on utilizing polyphenols in preventing aging-related disorders are getting growing attention, we suggest the exploration of the beneficial effects of the combination of multiple polyphenols or polyphenol-rich foods, as this would be more physiologically relevant to daily life.

Improved Antioxidant Capacity of Black Tea Waste Utilizing PlantCrystals

Antioxidants are recommended to prevent and treat oxidative stress diseases. Plants are a balanced source of natural antioxidants, but the poor solubility of plant active molecules in aqueous media can be a problem for the formulation of pharmaceutical products. The potential of PlantCrystal technology is known to improve the extraction efficacy and antioxidant capacity (AOC) of different plants. However, it is not yet proved for plant waste. Black tea (BT) infusion is consumed worldwide and thus a huge amount of waste occurs as a result. Therefore, BT waste was recycled into PlantCrystals using small-scale bead milling. Their characteristics were compared with the bulk-materials and tea infusion, including particle size and antioxidant capacity (AOC) in-vitro. Waste PlantCrystals possessed a size of about 280 nm. Their AOC increased with decreasing size according to the DPPH (1,1-diphenyl-2-picrylhydrazyl) and ORAC (oxygen radical absorbance capacity) assays. The AOC of the waste increased about nine-fold upon nanonization, leading to a significantly higher AOC than the bulk-waste and showed no significant difference to the infusion and the used standard according to DPPH assay. Based on the results, it is confirmed that the PlantCrystal technology represents a natural, cost-effective plant-waste recycling method and presents an alternative source of antioxidant phenolic compounds.

Catechins as Tools to Understand the Molecular Basis of Neurodegeneration

Protein misfolding as well as the subsequent self-association and deposition of amyloid aggregates is implicated in the progression of several neurodegenerative disorders including Alzheimer's and Parkinson's diseases. Modulators of amyloidogenic aggregation serve as essential tools to dissect the underlying molecular mechanisms and may offer insight on potential therapeutic solutions. These modulators include green tea catechins, which are potent inhibitors of amyloid aggregation. Although catechins often exhibit poor pharmacokinetic properties and bioavailability, they are still essential tools for identifying the drivers of amyloid aggregation and for developing other aggregation modulators through structural mimicry. As an illustration of such strategies, here we review how catechins have been used to map the toxic surfaces of oligomeric amyloid-like species and develop catechin-based phenolic compounds with enhanced anti-amyloid activity.

Evaluation of the Anti-apoptotic and Anti-cytotoxic Effect of Epicatechin Gallate and Edaravone on SH-SY5Y Neuroblastoma Cells

Introduction:

Parkinson disease (PD) is the second most common neurodegenerative disease affecting older individuals with signs of motor disability and cognitive impairment. Epicatechin (EC) and edaravone have neuroprotective effects most probably due to their antioxidant activity; however, a limited number of studies have considered their role in PD. This research aimed at investigating the neuroprotective effect of EC and edaravone in a neurotoxin-induced model of PD.

Methods:

An in vitro model of PD was made by subjecting SH-SY5Y neuroblastoma cells to neurotoxin: 6-hydroxydopamine (6-OHDA) 100 μM/well. The cytoprotective effect of EC and edaravone in five concentrations on cell viability was tested using the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay. The apoptotic assay was done by annexin V and propidium iodide method using flow cytometry.

Results:

According to the MTT assay analysis, EC and edaravone had protective effects against 6-OH DA-induced cytotoxicity in SH-SY5Y neuroblastoma cells that were much more significant for edaravone and also a relative synergistic effect between EC and edaravone was observed. The apoptotic analysis showed that edaravone alone could decrease early and late apoptosis, whereas EC diminished early apoptosis, but enhanced late apoptosis and necrosis. Besides, co-treatment of edaravone and EC had a synergistic effect on decreasing apoptosis and increasing cell viability.

Conclusion:

The protective effect of edaravone on apoptosis and cytotoxicity was demonstrated clearly and EC had a synergistic effect with edaravone.

Preventive Effects of Grape Extract on Ischemia/Reperfusion-Induced Acute Kidney Injury in Mice

Since grape extract (GE) contains oligomeric proanthocyanidins and numerous polyphenols, dietary GE supplements may exert protective effects against various diseases. The present study investigated the pharmacological effects of GE derived from Chardonnay in vitro and in vivo. GE (100 µg/mL) completely inhibited tumor necrosis factor-α-induced endothelin-1, monocyte chemoattractant protein-1, interleukin-1β, and intercellular adhesion molecule-1 gene expression in cultured endothelial cells. GE also strongly stimulated the phosphatidylinositol 3-kinase (PI3K)/Akt/endothelial nitric oxide synthase (eNOS) pathway. In the in vivo study, the effects of GE on ischemic acute kidney injury (AKI) were examined using male C57bl/6J wild-type and eNOS^-/- mice. Right nephrectomized mice were exposed to 45 min of ischemia in the left kidney and this was followed by reperfusion. Although renal functional parameters in AKI mice significantly increased 48 h after reperfusion, the administration of GE (0.1 and 1 mg/kg, intravenous (i.v.)) 5 min before ischemia dose-dependently improved post-ischemic renal dysfunction in wild-type mice. Renal histopathological studies on AKI mice revealed tubular necrosis, proteinaceous casts in tubuli, and medullary congestion. The administration of GE ameliorated this damage in wild-type mice, but not in eNOS^-/- mice. Furthermore, GE significantly restored decreases in the renal nitric oxide metabolite content due to ischemia in wild-type mice, but not in eNOS^-/- mice. Thus, eNOS is closely involved in the renoprotective effects of GE, strongly suggesting that GE supplements are useful as a prophylactic treatment for the development of ischemic AKI.

Green Synthesis of Mg0.99 Zn0.01O Nanoparticles for the Fabrication of κ-Carrageenan/NaCMC Hydrogel in order to Deliver Catechin

Currently, the role of the nanoparticles in the structure of the composites and their benefits for the health of the body is valuable. In this study, the effects of the doping on the structural and morphological properties of the hydrogels using a Mg co-doped ZnO hydrogel, which has been fabricated by the sol–gel process, have been investigated. Then, a hydrogel containing nanoparticle and a hydrogel without any nanoparticles was produced as a control. The hydrogels were loaded with catechin and the related characterization was evolved based on the new structure of the matrices. The Mg_0.99Zn_0.01O nanoparticles were synthesized using a green synthesis method. To investigate the properties of the nanoparticles, zeta potential and XRD were studied. The field emission scanning electron microscopy (FESEM), FTIR, TGA, swelling Ratio, and compression tests were investigated for the hydrogels. Based on the results, FESEM showed a more compressed structure for hydrogels including nanoparticles rather than the hydrogels without a nanoparticle. The TGA showed a higher decomposition temperature in the hydrogels including nanoparticles. The swelling ratio of hydrogels containing a nanoparticle was higher than the control hydrogel. κ-Carrageenan/ Mg_0.99Zn_0.01O/NaCMC/Catechin had the highest swelling ratio (44.15%) rather than the κ-Carrageenan/NaCMC (33.22%). Mg_0.99Zn_0.01O nanoparticles presented a stronger structure of hydrogels in the compression test. It is concluded that the role of the synthesized nanoparticle is critical in the structure of the hydrogel.

Nutraceutical Boom in Cancer: Inside the Labyrinth of Reactive Oxygen Species

In recent years, epidemiological studies have shown that food is a very powerful means for maintaining a state of well-being and for health prevention. Many degenerative, autoimmune and neoplastic diseases are related to nutrition and the nutrient-organism interaction could define the balance between health and disease. Nutrients and dietary components influence epigenetic phenomena and modify drugs response; therefore, these food-host interactions can influence the individual predisposition to disease and its potential therapeutic response. Do nutraceuticals have positive or negative effects during chemotherapy? The use of nutraceutical supplements in cancer patients is a controversial debate without a definitive conclusion to date. During cancer treatment, patients take nutraceuticals to alleviate drug toxicity and improve long-term results. Some nutraceuticals may potentiate the effect of cytotoxic chemotherapy by inducing cell growth arrest, cell differentiation, and alteration of the redox state of cells, but in some cases, high levels of them may interfere with the effectiveness of chemotherapy, making cancer cells less reactive to chemotherapy. In this review, we highlighted the emerging opinions and data on the pros and cons on the use of nutraceutical supplements during chemotherapy.

Flavonoids as Anticancer Agents

Flavonoids are polyphenolic compounds subdivided into 6 groups: isoflavonoids, flavanones, flavanols, flavonols, flavones and anthocyanidins found in a variety of plants. Fruits, vegetables, plant-derived beverages such as green tea, wine and cocoa-based products are the main dietary sources of flavonoids. Flavonoids have been shown to possess a wide variety of anticancer effects: they modulate reactive oxygen species (ROS)-scavenging enzyme activities, participate in arresting the cell cycle, induce apoptosis, autophagy, and suppress cancer cell proliferation and invasiveness. Flavonoids have dual action regarding ROS homeostasis—they act as antioxidants under normal conditions and are potent pro-oxidants in cancer cells triggering the apoptotic pathways and downregulating pro-inflammatory signaling pathways. This article reviews the biochemical properties and bioavailability of flavonoids, their anticancer activity and its mechanisms of action.

Preclinical Pharmacological Activities of Epigallocatechin-3-gallate in Signaling Pathways: An Update on Cancer

Epigallocatechin gallate (EGCG) is the main bioactive component of catechins predominantly present in svarious types of teas. EGCG is well known for a wide spectrum of biological activity as an anti-oxidative, anti-inflammatory, and anti-tumor agent. The effect of EGCG on cell death mechanisms via the induction of apoptosis, necrosis, and autophagy has been documented. Moreover, its anti-proliferative and chemopreventive action has been demonstrated in many cancer cell lines. It was also involved in the modulation of cyclooxygenase-2, in oxidative stress and inflammation of different cell processes. EGCG has been reported as a promising target for plasma membrane proteins, such as epidermal growth factor receptor (EGFR). In addition, it has been demonstrated a mechanism of action relying on the inhibition of ERK1/2, p38 MAPK, NF-κB, and vascular endothelial growth factor (VEGF). EGCG and its derivatives were used in proteasome inhibition and they were involved in epigenetic mechanisms. In summary, EGCG is the most predominant and bioactive constituent of teas and it has a pivotal role in cancer prevention. Its preclinical pharmacological activities are associated with complex molecular mechanisms that involve numerous signaling pathways.

Effects of DCM Leaf Extract of Gnidia glauca (Fresen) on Locomotor Activity, Anxiety, and Exploration-Like Behaviors in High-Fat Diet-Induced Obese Rats

Obesity is the main component of metabolic syndromes involving distinct etiologies that target different underlying behavioral and physiological functions within the brain structures and neuronal circuits. An alteration in the neuronal circuitry stemming from abdominal or central obesity stimulates a cascade of changes in neurochemical signaling that directly or indirectly mediate spontaneously emitted behaviors such as locomotor activity patterns, anxiety, and exploration. Pharmacological agents available for the treatment of neurologic disorders have been associated with limited potency and intolerable adverse effects. These have necessitated the upsurge in the utilization of herbal prescriptions due to their affordability and easy accessibility and are firmly embedded within wider belief systems of many people. Gnidia glauca has been used in the management of many ailments including obesity and associated symptomatic complications. However, its upsurge in use has not been accompanied by empirical determination of these folkloric claims. The present study, therefore, is aimed at determining the modulatory effects of dichloromethane leaf extract of Gnidia glauca on locomotor activity, exploration, and anxiety-like behaviors in high-fat diet-induced obese rats in an open-field arena. Obesity was experimentally induced by feeding the rats with prepared high-fat diet and water ad libitum for 6 weeks. The in vivo antiobesity effects were determined by oral administration of G. glauca at dosage levels of 200, 250, and 300 mg/kg body weight in high-fat diet-induced obese rats from the 6^th to 12^th week. Phytochemical analysis was done using gas chromatography linked to mass spectroscopy. Results indicated that Gnidia glauca showed anxiolytic effects and significantly increased spontaneous locomotor activity and exploration-like behaviors in HFD-induced obese rats. The plant extract also contained phytocompounds that have been associated with amelioration of the main neurodegenerative mediators, viz., inflammation and oxidative stress. These findings provide “qualified leads” for the synthesis of new alternative therapeutic agents for the management of neurologic disorders. However, there is a need to conduct toxicity studies of Gnidia glauca to establish its safety profiles.

Modulation of Aquaporins by Dietary Patterns and Plant Bioactive Compounds

Healthful dietary patterns and bioactive compounds supplementation can be adopted as simple and easy intervention to prevent, attenuate or cure clinical disorders, especially when it comes to degenerative and chronic diseases. In the recent years, a growing body of evidence indicates Aquaporins (AQPs), a family of membrane channel proteins widely expressed in the human body, among the targets underlying the beneficial action played by some food nutrients and phytochemical compounds. Here, we provide an overview of what is known regarding the AQP modulation exerted by healthful dietary patterns and plant polyphenols.

Areca nut procyanidins prevent ultraviolet light B-induced photoaging via suppression of cyclooxygenase-2 and matrix metalloproteinases in mouse skin

Chronic exposure to solar ultraviolet (UV) light induces photoaging in human skin. Our previous results have shown that areca nut procyanidins (ANPs) have antioxidant capacity and possess potential anti-inflammatory effects. Here, we aimed to investigate the effect of ANPs on UVB-induced photoaging. In the present study, dorsal skin of CD-1 mice was exposed to UVB at a minimal erythema dose (130 mJ/cm²) throughout a 3-week period. The effects of ANPs and epigallocatechin-3-gallate (EGCG), a polyphenolic constituent of green tea, on UVB-induced photoaging were compared. The results show that oral administration of ANP prevented UVB-induced photoaging, indicated by epidermal thickness and collagen disorientation, and inhibited UVB-induced expression of cyclooxygenase-2 and matrix metalloproteinases (MMPs), such as MMP-2, MMP-9, and TIMP1. The protective potential of ANP on UVB-induced photodamage was comparable to that of EGCG. These data suggest that ANP could be useful as a dietary supplement to attenuate solar UVB-induced premature skin aging.

Croatian Wines from Native Grape Varieties Have Higher Distinct Phenolic (Nutraceutic) Profiles than Wines from Non-Native Varieties with the Same Geographic Origin

Croatian wines made from native (Plavac mali and Teran) and non-native grape varieties (Cabernet Sauvignon and Merlot), all grown in Croatian coastal regions, were investigated. Analyses included measurements of antioxidant activities, total phenolic contents and concentrations of non-colored phenolic compounds, chosen based on their known nutraceutical properties. Plavac mali wines were distinguished by higher antioxidant activity, total phenolic content and catechin concentrations but lower flavonol concentrations. Teran wines had higher hydroxytyrosol, myricetin and resveratrol concentrations. Merlot and Cabernet Sauvignon wines had higher flavonol concentrations (except myricetin). Canonical analysis was successful in discriminating Plavac mali from Teran wines, and both varieties were separated from non-native varieties. The results indicate distinct genetic potentials of studied varieties and enable wine authentication based on the investigated bioactive compounds.

Natural antidotes and management of metal toxicity

The global burden of heavy metal especially mercury, arsenic, lead, and cadmium toxicities remains a significant public health challenge. Developing nations are particularly at high risk and carry the highest burden of this hazard. Chelation therapy has been the mainstay for treatment of heavy metal poisoning where the chelating agent binds metal ions to form complex ring-like structures called "chelates" to enhance their elimination from the body. Metal chelators have some drawbacks such as redistribution of some heavy metals from other tissues to the brain thereby increasing its neurotoxicity, causing loss of essential metals such as copper and zinc as well as some serious adverse effects, e.g., hepatotoxicity. The use of natural antidotes, which are easily available, affordable, and with little or no side effects compared to the classic metal chelators, is the focus of this review and suggested as cheaper options for developing nations in the treatment of heavy metal poisoning.

Red wine and green tea flavonoids are cis-allosteric activators and competitive inhibitors of glucose transporter 1 (GLUT1)-mediated sugar uptake

The antioxidant- and flavonoid-rich contents of red wine and green tea are reported to offer protection against cancer, cardiovascular disease, and diabetes. Some studies, however, show that flavonoids inhibit GLUT1-mediated, facilitative glucose transport, raising the possibility that their interaction with GLUT1 and subsequent downstream effects on carbohydrate metabolism may also impact health. The present study explores the structure-function relationships of flavonoid-GLUT1 interactions. We find that low concentrations of flavonoids act as cis-allosteric activators of sugar uptake, whereas higher concentrations competitively inhibit sugar uptake and noncompetitively inhibit sugar exit. Studies with heterologously expressed human GLUT1, -3, or -4 reveal that quercetin-GLUT1 and -GLUT4 interactions are stronger than quercetin-GLUT3 interactions, that epicatechin gallate (ECG) is more selective for GLUT1, and that epigallocatechin gallate (EGCG) is less GLUT isoform-selective. Docking studies suggest that only one flavonoid can bind to GLUT1 at any instant, but sugar transport and ligand-binding studies indicate that human erythrocyte GLUT1 can bind at least two flavonoid molecules simultaneously. Quercetin and EGCG are each characterized by positive, cooperative binding, whereas ECG shows negative cooperative binding. These findings support recent studies suggesting that GLUT1 forms an oligomeric complex of interacting, allosteric, alternating access transporters. We discuss how modulation of facilitative glucose transporters could contribute to the protective actions of the flavonoids against diabetes and Alzheimer's disease.

Plasma tea catechins and risk of cardiovascular disease in middle-aged Japanese subjects: The JPHC study

BACKGROUND AND AIMS

Although a potential benefit of drinking green tea has been suggested to reduce the development of cardiovascular disease, no study has investigated the relationship between plasma tea catechin and risk of cardiovascular disease.

METHODS

A prospective, nested case-control study was conducted to examine the association between plasma tea catechin and risk of stroke and coronary heart disease (CHD) in a cohort of 29,876 men and women aged 40-69 years without history of heart disease, stroke or cancer. Participants completed a survey and donated blood samples between 1990 and 1994, and were followed-up through 2008. A total of 1132 stroke cases and 209 CHD cases, matched 1:1 to controls (n = 1132) for stroke and 1:2 to controls (n = 418) for CHD, were included in the analysis.

RESULTS

We found no significant association between plasma tea catechin and the incidence of stroke or CHD in either men or women. However, we found that high plasma levels of epigallocatechin gallate (EGCG) were associated with reduced risk of stroke in non-smoking men; the adjusted odds ratio (95% CI) for the highest vs. non-detectable levels was 0.53 (0.29-0.98). The respective OR in male smokers was 1.23 (0.75-2.16). A significant interaction by smoking status was found for the highest vs. non-detected plasma EGCG in relation to stroke (p-for-interaction: p = 0.09).

CONCLUSIONS

Plasma tea catechin was not associated with reduced risks of either stroke or CHD, while a protective effect of certain tea catechin on stroke risk is suggested for male non-smokers.

The Role of Catechins in Cellular Responses to Oxidative Stress

Catechins are polyphenolic compounds—flavanols of the flavonoid family found in a variety of plants. Green tea, wine and cocoa-based products are the main dietary sources of these flavanols. Catechins have potent antioxidant properties, although in some cases they may act in the cell as pro-oxidants. Catechins are reactive oxygen species (ROS) scavengers and metal ion chelators, whereas their indirect antioxidant activities comprise induction of antioxidant enzymes, inhibition of pro-oxidant enzymes, and production of the phase II detoxification enzymes and antioxidant enzymes. Oxidative stress and ROS are implicated in aging and related dysfunctions, such as neurodegenerative disease, cancer, cardiovascular diseases, and diabetes. Due to their antioxidant properties, catechins may be beneficial in preventing and protecting against diseases caused by oxidative stress. This article reviews the biochemical properties of catechins, their antioxidant activity, and the mechanisms of action involved in the prevention of oxidative stress-caused diseases.

Pharmacological values and therapeutic properties of black tea (Camellia sinensis): A comprehensive overview

Medicinal plants are essential parts of traditional medicine due to their phytochemical constituents having pharmacological values and therapeutic applications. Black tea have thousands of various biological compounds such as flavonoids (Thearubigins (TRs) and theaflavins (TFs) and catechins), amino acids (L.theanine), vitamins (A, C, K), phenolic acids (caffeic acid (CA), gallic acid (GA), chlorogenic acids (CGA) and cauramic acid), lipids, proteins, volatile compounds carbohydrates, β-carotene and fluoride that illustrated many promising pharmacological effects regarded as growth promoter, cardioprotector, potent cholesterol-lowering effect, antioxidant and antimicrobial, etc inhuman. Although there is an exponential growth in molecular evidence of cholesterol-lowering and antioxidant effect in human, there is still a lack of information of the pharmacological effects of black tea. To fill this information gap, therefore, this review article underscores broadening the new insight pertaining to black tea that could be used as safe food additive. This article also illuminates the interesting role of black tea as an herbal medicine that is the future demand to get rid of synthetic health promoters in the human health practice. Moreover, this information would be useful in terms of the low-cost practice of natural medicines with no residual effects, and a natural protection of the human being. In addition, further studies at a molecular level are needed to reveal its mechanism of action particularly for the hypocholesterolemic effect of black tea to overcome the heart-related diseases, fewer side effects and being a natural safeguard of human health.