Green tea polyphenol extract attenuates inflammation in interleukin-2-deficient mice, a model of autoimmunity

Medicinal Plants for the Treatment of Neuropathic Pain: A Review of Randomized Controlled Trials

Neuropathic pain is a disabling condition caused by various diseases and can profoundly impact the quality of life. Unfortunately, current treatments often do not produce complete amelioration and can be associated with potential side effects. Recently, herbal drugs have garnered more attention as an alternative or a complementary treatment. In this article, we summarized the results of randomized clinical trials to evaluate the effects of various phytomedicines on neuropathic pain. In addition, we discussed their main bioactive components and potential mechanisms of action to provide a better view of the application of herbal drugs for treating neuropathic pain.

Amelioration Effects and Regulatory Mechanisms of Different Tea Active Ingredients on DSS-Induced Colitis

The potential biological function of tea and its active components on colitis has attracted wide attention. In this study, different tea active ingredients including tea polyphenols (TPPs), tea polysaccharides (TPSs), theabrownin (TB), and theanine (TA) have been compared in the intervention of dextran sulfate sodium (DSS)-induced colitis in mice. Specifically, TPP showed the greatest effect on colitis since it reduced 60.87% of disease activity index (DAI) compared to that of the DSS-induced colitis group, followed by the reduction of 39.13% of TPS and 28.26% of TB on DAI, whereas there was no obvious alleviative effect of TA on colitis. TPP, TPS, and TB could regulate the composition and abundance of gut microbiota to increase the content of short-chain fatty acids (SCFAs) and enhance intestinal barrier function. Further evidence was observed that TPP and TPS regulated the activation of Nrf2/ARE and the TLR4/MyD88/NF-κB P65 pathway to alleviate the colitis. Results of cell experiments demonstrated that TPP showed the greatest antiapoptosis and mitochondrial function protective capability among the tea ingredients via inhibiting the Cytc/Cleaved-caspase-3 signaling pathway. In summary, the superior anticolitis activity of TPP compared to TPS and TB is primarily attributed to its unique upregulation of the abundance of Akkermansia and its ability to regulate the mitochondrial function.

International consensus statement on allergy and rhinology: Allergic rhinitis - 2023

BACKGROUND

In the 5 years that have passed since the publication of the 2018 International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis (ICAR-Allergic Rhinitis 2018), the literature has expanded substantially. The ICAR-Allergic Rhinitis 2023 update presents 144 individual topics on allergic rhinitis (AR), expanded by over 40 topics from the 2018 document. Originally presented topics from 2018 have also been reviewed and updated. The executive summary highlights key evidence-based findings and recommendation from the full document.

METHODS

ICAR-Allergic Rhinitis 2023 employed established evidence-based review with recommendation (EBRR) methodology to individually evaluate each topic. Stepwise iterative peer review and consensus was performed for each topic. The final document was then collated and includes the results of this work.

RESULTS

ICAR-Allergic Rhinitis 2023 includes 10 major content areas and 144 individual topics related to AR. For a substantial proportion of topics included, an aggregate grade of evidence is presented, which is determined by collating the levels of evidence for each available study identified in the literature. For topics in which a diagnostic or therapeutic intervention is considered, a recommendation summary is presented, which considers the aggregate grade of evidence, benefit, harm, and cost.

CONCLUSION

The ICAR-Allergic Rhinitis 2023 update provides a comprehensive evaluation of AR and the currently available evidence. It is this evidence that contributes to our current knowledge base and recommendations for patient evaluation and treatment.

Gut Bacterial Indole-3-acetic Acid Induced Immune Promotion Mediates Preventive Effects of Fu Brick Tea Polyphenols on Experimental Colitis

Ulcerative colitis has been consistently associated with gut microbiota imbalance and disturbed immune system. Emerging research suggests a protective function of polyphenols on prevention and treatment of ulcerative colitis, yet underlying mechanisms remain unclear. Fu brick tea, a postfermented tea, contains abundant polyphenols with anti-inflammatory and antioxidant properties. In the present study, we found that prophylactic supplementation of polyphenols extracted from Fu brick tea (FBTP) dose-dependently alleviated colitis symptoms, immune cells infiltration, and pro-inflammatory cytokines secretion in mice suffering dextran sulfate sodium induced murine colitis. FBTP substantially reshaped gut microbiota and promoted microbial transformation of tryptophan into indole-3-acetic acid (I3A), thereafter leading to aryl hydrocarbon receptor (AHR)-mediated protection from colitis through enhanced expressions of IL-22 and tight junction proteins (i.e., ZO-1, occluding and claudin-1) in colon. Multiomics integration analyses revealed strong connections between I3A, tryptophan-metabolizing bacteria, AHR activity, and pathological phenotypes of colitis. Notably, FBTP failed to significantly alleviate colitis symptoms in the absence of gut microbiota, while intragastric administration of I3A could imitate benefits of FBTP on colitis alleviation and intestinal epithelial homeostasis through a direct enhancement in AHR activity in microbiota-depleted mice. These findings further determine the key role of gut microbiota controlled I3A-AHR signaling in mediating the FBTP on colitis alleviation. This study provides the first data proposing the FBTP as a natural prebiotic for colitis alleviation through the gut microbiota-dependent modulation of the AHR pathway. Most importantly, we also identified I3A as a key microbial metabolite targeted by FBTP for exhibiting health-promoting effects.

Catechins: Protective mechanism of antioxidant stress in atherosclerosis

Tea has long been valued for its health benefits, especially its potential to prevent and treat atherosclerosis (AS). Abnormal lipid metabolism and oxidative stress are major factors that contribute to the development of AS. Tea, which originated in China, is believed to help prevent AS. Research has shown that tea is rich in catechins, which is considered a potential source of natural antioxidants. Catechins are the most abundant antioxidants in green tea, and are considered to be the main compound responsible for tea's antioxidant activity. The antioxidant properties of catechins are largely dependent on the structure of molecules, and the number and location of hydroxyl groups or their substituents. As an exogenous antioxidant, catechins can effectively eliminate lipid peroxidation products. They can also play an antioxidant role indirectly by activating the endogenous antioxidant system by regulating enzyme activity and signaling pathways. In this review, we summarized the preventive effect of catechin in AS, and emphasized that improving the antioxidant effect and lipid metabolism disorders of catechins is the key to managing AS.

Green tea EGCG effectively alleviates experimental colitis in middle-aged male mice by attenuating multiple aspects of oxi-inflammatory stress and cell cycle deregulation

Age-dependent increased risk of inflammatory bowel diseases such as ulcerative colitis is being increasingly realized, and yet therapies targeting this disorder within the purview of aging are limited. The present study attempted to assess the efficacy of green tea epigallocatechin gallate (EGCG) consumption in preventing the severity and progression of dextran sulphate sodium (DSS)-induced ulcerative colitis in 18 months old middle-aged male mice. Acute colitis was induced in animals using DSS and protective effects of EGCG consumption were examined. Different parameters related to disease progression and molecular markers related to oxi-inflammatory stress, localized and systemic cytokine response, epithelial barrier integrity, and cell cycle progression profile were evaluated. DSS treatment induced rapid and severe symptoms of colitis such as consistently increased DAI score, shortened and inflamed colon accompanied by increased levels of inflammatory proteins (TNFα/IL-6/IL-1β) in both the colon tissue and cultured splenocytes indicating exaggerated Th1 immune response. Markers of oxidative stress increased while antioxidant defences and the expression of tight junction genes in the colonic cells were attenuated. Dysregulation in the expression of cell cycle inhibitory genes (p53/p21^WAF1/p16^Ink4a) indicated possible induction of colitis-induced dysplasia. On the other hand, EGCG consumption strongly attenuated all the measured ostensible as well as molecular markers of the disease progression as evidenced by improved DAI score, cellular antioxidant capacity, attenuated Th1 cytokine response both in the colon and cultured splenocytes, enhanced expression of tight junction genes, and cell cycle inhibitors thereby suggesting systemic effects of EGCG. Together, these observations suggest that drinking EGCG-rich green tea can be a significant way of managing the severity of colitis during aging.

Recent development in fabrication and evaluation of phenolic-dietary fiber composites for potential treatment of colonic diseases

Phenolics have been shown by in vitro and animal studies to have multiple pharmacological effects against various colonic diseases. However, their efficacy against colonic diseases, such as inflammatory bowel diseases, Crohn's disease, and colorectal cancer, is significantly compromised due to their chemical instability and susceptibility to modification along the gastrointestinal tract (GIT) before reaching the colonic site. Dietary fibers are promising candidates that can form phenolic-dietary fiber composites (PDC) to carry phenolics to the colon, as they are natural polysaccharides that are non-digestible in the upper intestinal tract but can be partially or fully degradable by gut microbiota in the colon, triggering the release at this targeted site. In addition, soluble and fermentable dietary fibers confer additional health benefits as prebiotics when used in the PDC fabrication, and the possibility of synergistic relationship between phenolics and fibers in alleviating the disease conditions. The functionalities of PDC need to be characterized in terms of their particle characteristics, molecular interactions, release profiles in simulated digestion and colonic fermentation to fully understand the metabolic fate and health benefits. This review examines recent advancements regarding the approaches for fabrication, characterization, and evaluation of PDC in in vitro conditions.

A Natural Plant Source-Tea Polyphenols, a Potential Drug for Improving Immunity and Combating Virus

The coronavirus disease 2019 (COVID-19) is still in a global epidemic, which has profoundly affected people’s lives. Tea polyphenols (TP) has been reported to enhance the immunity of the body to COVID-19 and other viral infectious diseases. The inhibitory effect of TP on COVID-19 may be achieved through a series of mechanisms, including the inhibition of multiple viral targets, the blocking of cellular receptors, and the activation of transcription factors. Emerging evidence shows gastrointestinal tract is closely related to respiratory tract, therefore, the relationship between the state of the gut–lung axis microflora and immune homeostasis of the host needs further research. This article summarized that TP can improve the disorder of flora, reduce the occurrence of cytokine storm, improve immunity, and prevent COVID-19 infection. TP may be regarded as a potential and valuable source for the design of new antiviral drugs with high efficiency and low toxicity.

Anti-inflammatory Effects of GTE in Eye Diseases

Ocular inflammation is a common complication of various eye diseases with wide consequences from irritations to potentially sight-threatening complications. Green tea is a popular beverage throughout the world. One of the proven health benefits of consuming green tea extract (GTE) is anti-inflammation. Catechins are the biologically active constituents of GTE. In in vitro and in vivo studies, GTE and catechins present inhibition of inflammatory responses in the development of ocular inflammation including infectious, non-infectious or autoimmune, and oxidative-induced complications. Research on the ocular inflammation in animal models has made significant progress in the past decades and several key disease mechanisms have been identified. Here we review the experimental investigations on the effects of GTE and catechins on various ocular inflammation related diseases including glaucoma, age-related macular degeneration, uveitis and ocular surface inflammation. We also review the pharmacokinetics of GTE constituents and safety of green tea consumption. We discuss the insights and perspectives of these experimental results, which would be useful for future development of novel therapeutics in human.

A Comprehensive Review of the Potential Use of Green Tea Polyphenols in the Management of COVID-19

Green tea is produced from Camellia sinensis (L.) buds and leaves that have not gone through the oxidation and withering processes used to produce black and oolong teas. It was originated in China, but its cultivation and production have expanded to other Eastern Asian countries. Several polyphenolic compounds, including flavandiols, flavonols, flavonoids, and phenolic acids, are found in green tea and may constitute greater than 30% of the dry weight. Flavonols, especially catechins, represent the majority of green tea polyphenols. Green tea polyphenolic compounds have been reported to confer several health benefits. This review describes the potential use of green tea polyphenols in the management of coronavirus disease 2019 (COVID-19). The immunomodulatory, antibacterial, antioxidant, and anti-inflammatory effects of green tea polyphenols have also been considered in this review. In addition to describing the bioactivities associated with green tea polyphenols, this review discusses the potential delivery of these biomolecules using a nanoparticle drug delivery system. Moreover, the bioavailability and toxicity of green tea polyphenols are also evaluated.

Immunomodulatory Effects of Green Tea Polyphenols

Green tea and its bioactive components, especially polyphenols, possess many health-promoting and disease-preventing benefits, especially anti-inflammatory, antioxidant, anticancer, and metabolic modulation effects with multi-target modes of action. However, the effect of tea polyphenols on immune function has not been well studied. Moreover, the underlying cellular and molecular mechanisms mediating immunoregulation are not well understood. This review summarizes the recent studies on the immune-potentiating effects and corresponding mechanisms of tea polyphenols, especially the main components of (-)-epigallocatechin-3-gallate (EGCG) and (-)-epicatechin-3-gallate (ECG). In addition, the benefits towards immune-related diseases, such as autoimmune diseases, cutaneous-related immune diseases, and obesity-related immune diseases, have been discussed.

Evolving Interplay Between Dietary Polyphenols and Gut Microbiota-An Emerging Importance in Healthcare

Polyphenols are natural plant compounds and are the most abundant antioxidants in the human diet. As the gastrointestinal tract is the primary organ provided to diet sections, the diet may be regarded as one of the essential factors in the functionality, integrity, and composition of intestinal microbiota. In the gastrointestinal tract, many polyphenols remain unabsorbed and may accumulate in the large intestine, where the intestinal microbiota are most widely metabolized. When assuming primary roles for promoting host well-being, this intestinal health environment is presented to the effect of external influences, including dietary patterns. A few different methodologies have been developed to increase solvency and transport across the gastrointestinal tract and move it to targeted intestinal regions to resolve dietary polyphenols at the low bioavailability. Polyphenols form a fascinating community among the different nutritional substances, as some of them have been found to have critical biological activities that include antioxidant, antimicrobial, or anticarcinogenic activities. Besides, it affects metabolism and immunity of the intestines and has anti-inflammatory properties. The well-being status of subjects can also benefit from the development of bioactive polyphenol-determined metabolites, although the mechanisms have not been identified. Even though the incredible variety of health-advancing activities of dietary polyphenols has been widely studied, their effect on intestinal biology adaptation, and two-way relationship between polyphenols and microbiota is still poorly understood. We focused on results of polyphenols in diet with biological activities, gut ecology, and the influence of their proportional links on human well-being and disease in this study.

Tea polyphenols inhibit the growth and virulence of ETEC K88

Diarrhea caused by Enterotoxigenic Escherichia coli (ETEC) causes high levels of morbidity and mortality in neonatal piglets. Owing to the abuse of antibiotics and emergence of drug resistance, antibiotics are no longer considered only beneficial, but also potentially harmful drugs. Supplements that can inhibit the growth of bacteria are expected to replace antibiotics. Tea polyphenols have numerous important biological functions, including antibacterial, antiviral, antioxidative, anti-inflammatory, and antihypertensive effects. We investigated the role of tea polyphenols in ETEC K88 infection using a mouse model. Pretreating with tea polyphenols attenuated the symptoms induced by ETEC K88. Furthermore, in a cell adherence assay, tea polyphenols inhibited ETEC K88 adherence to IPEC-J2 cells. When cells were infected with ETEC K88, mRNA and protein levels of claudin-1 were significantly decreased compared with those of control cells. However, when cells were pretreated with tea polyphenols, claudin-1 mRNA and protein levels were higher than those in cells without pretreatment upon cell infection with ETEC K88. TLR2 mRNA levels were also higher following cell infection with ETEC K88 when cells were pretreated with tea polyphenols. These data revealed that tea polyphenols could increase the barrier integrity of IPEC-J2 cells by upregulating expression of claudin-1 through activation of TLR2. Tea polyphenols had beneficial effects on epithelial barrier function. Therefore, tea polyphenols could be used as a novel strategy to control and treat pig infections caused by ETEC K88.

Protective Effect of Epigallocatechin-3-Gallate (EGCG) in Diseases with Uncontrolled Immune Activation: Could Such a Scenario Be Helpful to Counteract COVID-19?

Some coronavirus disease 2019 (COVID-19) patients develop acute pneumonia which can result in a cytokine storm syndrome in response to Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) infection. The most effective anti-inflammatory drugs employed so far in severe COVID-19 belong to the cytokine-directed biological agents, widely used in the management of many autoimmune diseases. In this paper we analyze the efficacy of epigallocatechin 3-gallate (EGCG), the most abundant ingredient in green tea leaves and a well-known antioxidant, in counteracting autoimmune diseases, which are dominated by a massive cytokines production. Indeed, many studies registered that EGCG inhibits signal transducer and activator of transcription (STAT)1/3 and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) transcription factors, whose activities are crucial in a multiplicity of downstream pro-inflammatory signaling pathways. Importantly, the safety of EGCG/green tea extract supplementation is well documented in many clinical trials, as discussed in this review. Since EGCG can restore the natural immunological homeostasis in many different autoimmune diseases, we propose here a supplementation therapy with EGCG in COVID-19 patients. Besides some antiviral and anti-sepsis actions, the major EGCG benefits lie in its anti-fibrotic effect and in the ability to simultaneously downregulate expression and signaling of many inflammatory mediators. In conclusion, EGCG can be considered a potential safe natural supplement to counteract hyper-inflammation growing in COVID-19.

Green Tea Encourages Growth of Akkermansia muciniphila

Trillions of microorganisms reside in the hosts' gut. Since diverse activities of gut microbiota affect the hosts' health status, maintenance of gut microbiota is important for maintaining human health. Green tea (GT) has multiple beneficial effects on energy metabolism with antiobesity, antidiabetic, and hypolipidemic properties. As GT contains a large amount of bioactive ingredients (e.g., catechins), which can be metabolized by microorganisms, it would be feasible that consumption of GT may cause compositional changes in gut microbiota, and that the changes in gut microbiota would be associated with the beneficial effects of GT. In this study, we demonstrated that consumption of GT extract relieves high-fat diet-induced metabolic abnormalities. Interestingly, GT administration significantly encouraged the growth of Akkermansia muciniphila (Akkermansia), a beneficial microorganism to relieve obesity and related metabolic disorders. Finally, we found that epigallocatechin gallate is the component of GT that stimulates the growth of Akkermansia. According to these data, we propose that GT could be a prebiotic agent for Akkermansia to treat metabolic syndromes.

Dietary polyphenol impact on gut health and microbiota

Polyphenols are naturally occurring compounds in plants and they are the most abundant antioxidants in the human diet. Due to their considerable structural diversity, this largely influences their bioavailability. Since a large proportion of polyphenols remains unabsorbed along the gastrointestinal tract, they may accumulate in the large intestine, where most of them are extensively metabolized by the intestinal microbiota. The formation of bioactive polyphenol-derived metabolites may also benefit the health status of the subjects, although the mechanisms have not been delineated. This review aims to highlight the impact of polyphenols on gut health and the modes of action could be through modulation of intestinal barrier function, innate and adaptive immune response, signaling pathways, as well as the ability to modify gut microbiota composition. The review will conclude by presenting future perspective and challenges of polyphenols application in food products to be used for preventing or treating diseases.

Nutritional applications and beneficial health applications of green tea and l-theanine in some animal species: A review

Green tea (Camellia sinensis) is a popular herbal plant with abundant health benefits, and thus, it has been used as a potent antioxidant for a long time. Based on the available literature, the diversity and the availability of multifunctional compounds in green tea offer its noteworthy potential against many diseases such as liver and heart diseases, inflammatory conditions and different metabolic syndromes. Owing to its bioactive constituents including caffeine, amino acids, l-theanine, polyphenols/flavonoids and carbohydrates among other potent molecules, green tea has many pharmacological and physiological effects. The effects of green tea include anti-oxidative, anti-inflammatory, anti-arthritic, anti-stress, hypolipidaemic, hypocholesterolaemic, skin/collagen protective, hepatoprotective, anti-diabetic, anti-microbial, anti-infective, anti-parasitic, anti-cancerous, inhibition of tumorigenesis and angiogenesis, anti-mutagenic, and memory and bone health-improving activities. Apart from its utilization in humans, green tea has also played a significant role in livestock production such as in dairy, piggery, goatry and poultry industries. Supplementation of animal feeds with green tea and its products is in line with the modern concepts of organic livestock production. Hence, incorporating green tea or green tea by-products into the diet of poultry and other livestock can enhance the value of the products obtained from these animals. Herein, an effort is made to extend the knowledge on the importance and useful applications of green tea and its important constituents in animal production including poultry. This review will be a guideline for researchers and entrepreneurs who want to explore the utilization of feeds supplemented with green tea and green tea by-products for the enhancement of livestock production.

EFFICACY OF CURCUMA LONGA IN THE TREATMENT OF DIVERSION COLITIS IN RATS

Background:

Diversion colitis is still very common in our country, since the stoma creation is a common practice especially in situations of trauma. needing treatment for this condition.

Aim:

To evaluate the therapeutic effect of rectal infusion of Curcuma longa (turmeric) in the excluded intestinal segment of rats.

Method:

Eighteen Wistar rats were used and submitted to colostomy: control group (n=8) under rectal saline infusion and group CL, receiving intra-rectal infusion of Curcuma longa extract (n=10). After 21 days of treatment they were submitted to euthanasia; the intestinal segment excluded from intestinal transit was resected and sent to histopathological evaluation, classifying the degree of inflammation and of vascular congestion.

Results:

The average of inflammation was 2.7 in the control group vs. 2.6 in the CL group (p=0.3125), while the mean vascular congestion was 2.3 and 2.1, respectively, in the control and CL groups (p=0.1642).

Conclusion:

Intra-rectal infusion of Curcuma longa extract was not able to minimize the inflammatory process or vascular congestion in the diversion colitis of rats subjected to colostomy.

Interactions of tea catechins with intestinal microbiota and their implication for human health

Tea catechins have attracted strong interests in pharmacological field for their extensive biological activities; however, their bioavailability in vivo is relatively low. Recent studies have shown tea catechins can modulate the composition of intestinal microbiota and help to improve hosts' health. Meanwhile, the gut flora plays a crucial role in regulating the production of the metabolites of tea catechins and their biological activity. Although the activities of tea catechins to promote intestinal micro-ecology have been extensively studied, little is known about the two-way phenol-microbial interactions. This review focuses on the modulatory effect of tea catechins on intestinal microbiota as well as the microbial degradation of tea catechins and the metabolites formed. Finally, the potential effects of tea catechins on chronic intestinal inflammation are emphasized.

Tea polyphenols suppress growth and virulence-related factors of Haemophilus parasuis

The bacterium Haemophilus parasuis (H. parasuis) is the primary cause of Glässer's disease. Currently, there are no effective vaccines that can confer protection against all H. parasuis serovars. Therefore, the present study aimed to investigate the effect of tea polyphenols on growth, expression of virulence-related factors, and biofilm formation of H. parasuis, as well as to evaluate their protective effects against H. parasuis challenge. Our findings demonstrated that tea polyphenols can inhibit H. parasuis growth in a dose-dependent manner and attenuate the biofilm formation of H. parasuis. In addition, tea polyphenols exerted inhibitory effects on the expression of H. parasuis virulence-related factors. Moreover, tea polyphenols could confer protection against a lethal dose of H. parasuis and can reduce pathological tissue damage induced by H. parasuis. In summary, our findings demonstrated the promising use of tea polyphenols as a novel treatment for H. parasuis infection in pigs.

International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis

BACKGROUND

Critical examination of the quality and validity of available allergic rhinitis (AR) literature is necessary to improve understanding and to appropriately translate this knowledge to clinical care of the AR patient. To evaluate the existing AR literature, international multidisciplinary experts with an interest in AR have produced the International Consensus statement on Allergy and Rhinology: Allergic Rhinitis (ICAR:AR).

METHODS

Using previously described methodology, specific topics were developed relating to AR. Each topic was assigned a literature review, evidence-based review (EBR), or evidence-based review with recommendations (EBRR) format as dictated by available evidence and purpose within the ICAR:AR document. Following iterative reviews of each topic, the ICAR:AR document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:AR document addresses over 100 individual topics related to AR, including diagnosis, pathophysiology, epidemiology, disease burden, risk factors for the development of AR, allergy testing modalities, treatment, and other conditions/comorbidities associated with AR.

CONCLUSION

This critical review of the AR literature has identified several strengths; providers can be confident that treatment decisions are supported by rigorous studies. However, there are also substantial gaps in the AR literature. These knowledge gaps should be viewed as opportunities for improvement, as often the things that we teach and the medicine that we practice are not based on the best quality evidence. This document aims to highlight the strengths and weaknesses of the AR literature to identify areas for future AR research and improved understanding.

Green tea (Camellia sinensis) and l-theanine: Medicinal values and beneficial applications in humans-A comprehensive review

Green tea (Camellia sinensis) is a famous herb, and its extract has been extensively used in traditional Chinese medicinal system. In this context, several studies have revealed its health benefits and medicinal potentialities for several ailments. With ever increasing scientific knowledge, search for safer, potential and novel type of health-related supplements quest, scientists are re-directing their research interests to explore natural resources i.e. medicinal herbs/plant derived compounds. Green tea consumption has gained a special attention and popularity in the modern era of changing lifestyle. The present review is aimed to extend the current knowledge by highlighting the importance and beneficial applications of green tea in humans for safeguarding various health issues. Herein, we have extensively reviewed, analyzed, and compiled salient information on green tea from the authentic published literature available in PubMed and other scientific databases. Scientific literature evidenced that owing to the bioactive constituents including caffeine, l-theanine, polyphenols/flavonoids and other potent molecules, green tea has many pharmacological and physiological functions. It possesses multi-beneficial applications in treating various disorders of humans. This review also provides in-depth insights on the medicinal values of green tea which will be useful for researchers, medical professionals, veterinarians, nutritionists, pharmacists and pharmaceutical industry. Future research emphasis and promotional avenues are needed to explore its potential therapeutic applications for designing appropriate pharmaceuticals, complementary medicines, and effective drugs as well as popularize and propagate its multidimensional health benefits.

Chronic Inflammatory Diseases and Green Tea Polyphenols

Chronic inflammatory diseases affect millions of people globally and the incidence rate is on the rise. While inflammation contributes to the tissue healing process, chronic inflammation can lead to life-long debilitation and loss of tissue function and organ failure. Chronic inflammatory diseases include hepatic, gastrointestinal and neurodegenerative complications which can lead to malignancy. Despite the millennial advancements in diagnostic and therapeutic modalities, there remains no effective cure for patients who suffer from inflammatory diseases. Therefore, patients seek alternatives and complementary agents as adjunct therapies to relieve symptoms and possibly to prevent consequences of inflammation. It is well known that green tea polyphenols (GrTPs) are potent antioxidants with important roles in regulating vital signaling pathways. These comprise transcription nuclear factor-kappa B mediated I kappa B kinase complex pathways, programmed cell death pathways like caspases and B-cell lymphoma-2 and intervention with the surge of inflammatory markers like cytokines and production ofcyclooxygenase-2. This paper concisely reviews relevant investigations regarding protective effects of GrTPs and some reported adverse effects, as well as possible applications for GrTPs in the treatment of chronic and inflammatory complications.

The gut microbiome and microbial translocation in multiple sclerosis

Individuals with multiple sclerosis (MS) have a distinct intestinal microbial community (microbiota) and increased low-grade translocation of bacteria from the intestines into the circulation. The observed change of intestinal bacteria in MS patients regulate immune functions involved in MS pathogenesis. These functions include: systemic and central nervous system (CNS) immunity (including peripheral regulatory T cell function), the blood-brain barrier (BBB) permeability and CNS-resident cell activity. This review discusses the MS intestinal microbiota implication on MS systemic- and CNS-immunopathology. We introduce the possible contributions of MS low-grade microbial translocation (LG-MT) to the development of MS, and end on a discussion on microbiota therapies for MS patients.

The role of dietary supplements in inflammatory bowel disease: a systematic review

Inflammatory bowel diseases (IBD) are chronic immune disorders of unclear aetiology. Dietary deficiencies may be a potential pathogenic factor in their development. Patients often take food supplements without knowledge of any evidence base. We have therefore assessed the evidence for food supplementation in the management of IBD. A PubMed search was performed for the terms Inflammatory bowel disease; nutritional deficiencies; dietary supplements; curcumin; green tea; vitamin D/other vitamins; folic acid; iron; zinc; probiotics; andrographis paniculata; and boswellia serrate. PubMed was used to search for all relevant articles published between January 1975 and September 2015. Curcumin supplementation has been reported to be effective in reducing the symptoms and the inflammatory indices in IBD patients. Similar results have been observed for green tea; however, pertinent studies are limited. Vitamin D supplementation may help to increase bone mineral density in IBD patients and to reduce disease activity. IBD patients with ileal resections higher than 20 cm may develop vitamin B12 deficiency that requires parenteral supplementation. There is no current evidence to support fat-soluble vitamin supplementation in IBD patients. Zinc and iron should be supplemented in selected cases. Probiotics (VSL#3) may reduce disease activity in IBD patients with pouchitis. Complementary and alternative medicines are used by IBD patients and some studies have shown promising results. In summary, attention to dietary factors such as curcumin, green tea and vitamins, including vitamins D and B12, appears to be beneficial and, if necessary, supplementation may be appropriate.

Bioactivity of Polyphenols: Preventive and Adjuvant Strategies toward Reducing Inflammatory Bowel Diseases-Promises, Perspectives, and Pitfalls

Inflammatory bowel diseases (IBDs) are characterized by autoimmune and inflammation-related complications of the large intestine (ulcerative colitis) and additional parts of the digestive tract (Crohn's disease). Complications include pain, diarrhoea, chronic inflammation, and cancer. IBD prevalence has increased during the past decades, especially in Westernized countries, being as high as 1%. As prognosis is poor and medication often ineffective or causing side effects, additional preventive/adjuvant strategies are sought. A possible approach is via diets rich in protective constituents. Polyphenols, the most abundant phytochemicals, have been associated with anti-inflammatory, antioxidant, immunomodulatory, and apoptotic properties. Locally reducing oxidative stress, they can further act on cellular targets, altering gene expression related to inflammation, including NF-κB, Nrf-2, Jak/STAT, and MAPKs, suppressing downstream cytokine formation (e.g., IL-8, IL-1β, and TNF-α), and boosting the bodies' own antioxidant status (HO-1, SOD, and GPx). Moreover, they may promote, as prebiotics, healthy microbiota (e.g., Bifidobacteria, Akkermansia), short-chain fatty acid formation, and reduced gut permeability/improved tight junction stability. However, potential adverse effects such as acting as prooxidants, or perturbations of efflux transporters and phase I/II metabolizing enzymes, with increased uptake of undesired xenobiotics, should also be considered. In this review, we summarize current knowledge around preventive and arbitrary actions of polyphenols targeting IBD.

Walnut Polyphenol Extract Attenuates Immunotoxicity Induced by 4-Pentylphenol and 3-methyl-4-nitrophenol in Murine Splenic Lymphocyte

4-pentylphenol (PP) and 3-methyl-4-nitrophenol (PNMC), two important components of vehicle emissions, have been shown to confer toxicity in splenocytes. Certain natural products, such as those derived from walnuts, exhibit a range of antioxidative, antitumor, and anti-inflammatory properties. Here, we investigated the effects of walnut polyphenol extract (WPE) on immunotoxicity induced by PP and PNMC in murine splenic lymphocytes. Treatment with WPE was shown to significantly enhance proliferation of splenocytes exposed to PP or PNMC, characterized by increases in the percentages of splenic T lymphocytes (CD3+ T cells) and T cell subsets (CD4+ and CD8+ T cells), as well as the production of T cell-related cytokines and granzymes (interleukin-2, interleukin-4, and granzyme-B) in cells exposed to PP or PNMC. These effects were associated with a decrease in oxidative stress, as evidenced by changes in OH, SOD, GSH-Px, and MDA levels. The total phenolic content of WPE was 34,800 ± 200 mg gallic acid equivalents/100 g, consisting of at least 16 unique phenols, including ellagitannins, quercetin, valoneic acid dilactone, and gallic acid. Taken together, these results suggest that walnut polyphenols significantly attenuated PP and PNMC-mediated immunotoxicity and improved immune function by inhibiting oxidative stress.

Safety of a Bioactive Polyphenol Dietary Supplement in Pediatric Subjects with Acute Diarrhoea

The hematological and clinical chemistry profile for children aged 6 months to 5 years with acute diarrhoea was measured in a double blind clinical trial. Subjects were randomized to the study group (N = 44) given a bioactive polyphenol dietary supplement in oral rehydration solution (ORS) or to the control group (N = 41) given distilled water as a placebo in ORS twice daily for up to 4 days. All subjects received 10 mg zinc daily for the 4 days in the study. Venous blood was collected for complete blood count, electrolytes, liver function, and creatinine upon enrollment (baseline) and at the end of 4 days (end of study); mean values were compared by 95% confidence intervals. Overall, blood factors measured either remained the same over the 4 days or increased or decreased at the same levels between the two groups during the study period. All values were within accepted ranges for paediatric subjects except serum AST (SGOT), where the mean value of the study group approached the upper bound of the range on day 4 but was comparable to the value of the control group. Consumption of this supplement twice daily for 4 days is safe for children and infants.

The cardioprotective power of leaves

Lack of physical activity, smoking and/or inappropriate diet can contribute to the increase of oxidative stress, in turn affecting the pathophysiology of cardiovascular diseases. Strong anti-oxidant properties of plant polyphenolic compounds might underlie their cardioprotective activity. This paper reviews recent findings on the anti-oxidant activity of plant leaf extracts and emphasizes their effects on blood platelets, leukocytes and endothelial cells - the targets orchestrating the development and progression of cardiovascular diseases. We also review the evidence linking supplementation with plant leaf extracts and the risk factors defining the metabolic syndrome. The data point to the importance of leaves as an alternative source of polyphenolic compounds in the human diet and their role in the prevention of cardiovascular diseases.

Induction of cellular and molecular immunomodulatory pathways by vitamin A and flavonoids

INTRODUCTION

A detailed study of reports on the immunomodulatory properties of vitamin A and select flavonoids may pave the way for using these natural compounds or compounds with similar structures in novel drug and vaccine designs against infectious and autoimmune diseases and cancers.

AREAS COVERED

Intracellular transduction pathways, cellular differentiation and functional immunomodulatory responses have been reviewed. The reported studies encompass in vitro, in vivo preclinical and clinical studies that address the role of vitamin A and select flavonoids in induction of innate and adaptive B- and T-cell responses, including TH1, TH2 and regulatory T cells (Treg).

EXPERT OPINION

While the immunomodulatory role of vitamin A, and related compounds, is well-established in many preclinical studies, its role in humans has begun to gain wider acceptance. In contrast, the role of flavonoids is mostly controversial in clinical trials, due to the diversity of the various classes of these compounds, and possibly due to the purity and the selected doses of the compounds. However, current preclinical and clinical studies warrant further detailed studies of these promising immunomodulatory compounds.

Dietary agents and phytochemicals in the prevention and treatment of experimental ulcerative colitis

Inflammatory bowel diseases (IBDs), consisting mainly of ulcerative colitis (UC) and Crohn's disease (CD), are important immune-mediated diseases of the gastrointestinal tract. The etiology of the disease includes environmental and genetic factors. Its management presents a constant challenge for gastroenterologists and conventional surgeon. 5-Amninosalicylates, antibiotics, steroids, and immune modulators have been used to reduce the symptoms and for maintenance of remission. Unfortunately, long-term usage of these agents has been found to lead to severe toxicities, which are deterrent to the users. Pre-clinical studies carried out in the recent past have shown that certain dietary agents, spices, oils, and dietary phytochemicals that are consumed regularly possess beneficial effects in preventing/ameliorating UC. For the first time, this review addresses the use of these dietary agents and spices in the treatment and prevention of IBD and also emphasizes on the mechanisms responsible for their effects.

Animal models of ulcerative colitis and their application in drug research

The specific pathogenesis underlying inflammatory bowel disease is complex, and it is even more difficult to decipher the pathophysiology to explain for the similarities and differences between two of its major subtypes, Crohn's disease and ulcerative colitis (UC). Animal models are indispensable to pry into mechanistic details that will facilitate better preclinical drug/therapy design to target specific components involved in the disease pathogenesis. This review focuses on common animal models that are particularly useful for the study of UC and its therapeutic strategy. Recent reports of the latest compounds, therapeutic strategies, and approaches tested on UC animal models are also discussed.

Animal models of ulcerative colitis and their application in drug research

The specific pathogenesis underlying inflammatory bowel disease is complex, and it is even more difficult to decipher the pathophysiology to explain for the similarities and differences between two of its major subtypes, Crohn's disease and ulcerative colitis (UC). Animal models are indispensable to pry into mechanistic details that will facilitate better preclinical drug/therapy design to target specific components involved in the disease pathogenesis. This review focuses on common animal models that are particularly useful for the study of UC and its therapeutic strategy. Recent reports of the latest compounds, therapeutic strategies, and approaches tested on UC animal models are also discussed.

Green Tea Polyphenols and Sulfasalazine have Parallel Anti-Inflammatory Properties in Colitis Models

Background: There is no cure for autoimmune chronic inflammatory bowel disease (IBD). IBD patients commonly use complementary and alternative medications of which the safety, efficacy, and interaction with standard-of-care therapies are not fully known. Thus the consequences can become life-threatening. Sulfasalazine commonly used in IBD, potentially has severe adverse effects, including infertility, pulmonary fibrosis, lack of response, and ultimately patients may require intestinal resection. We hypothesized that green tea polyphenols (GrTP, EGCG) and sulfasalazine have similar anti-inflammatory properties.

Methods: BALB/c mice received Dextran sodium sulfate (DSS) to induce colitis (ulcerative colitis model). Exposure of IL-10 deficient mice (BALB/c-background) to normal microbiota provoked enterocolitis (mimics Crohn’s disease). Animals were treated with agents incorporated into daily diets. Control animals received sham treatment.

Results: DSS-treated animals developed severe bloody diarrhea and colitis (score 0–4, 3.2 ± 0.27). IL-10 deficient mice developed severe enterocolitis as manifested by diarrhea, rectal prolapse, and colonic lesions. Animals tolerated regimens (GrTP, EGCG, sulfasalazine) with no major side effects, and further developed less severe colitis. IL-10 deficient animals became moribund on high dose, while tolerated low and Mid doses with significant improved symptoms of enterocolitis. GrTP, EGCG, and sulfasalazine significantly ameliorated colonic damage and histological scores in treated animals in a similar manner (GrTP vs. DSS p < 0.05; EGCG, sulfasalazine vs. DSS p < 0.01). The inflammatory markers TNFα (3-fold), IL-6 (14-fold), and serum amyloid A (40-fold) increased in colitic animals and significantly decreased with treatment regiments. In contrast, circulatory leptin levels decreased in colitic animals (twofold). EGCG additionally reduced leptin levels (p < 0.01) while GrTP and sulfasalazine had no effect on leptin levels (p < 0.05). Hepatic and colonic antioxidants were significantly depleted in colitic animals and treatment regiments significantly restored antioxidants levels.

Conclusion: GrTP and EGCG improved antioxidants levels and attenuated severity of colitis analogous to sulfasalazine. Future studies will reveal whether polyphenols can become an alternative/additive therapy for IBD therapy in humans.

Modulation of colonic inflammation in Mdr1a(-/-) mice by green tea polyphenols and their effects on the colon transcriptome and proteome

Animal models are an important tool to understand the complex pathogenesis of inflammatory bowel diseases (IBDs). This study tested the anti-inflammatory potential of a green tea extract rich in polyphenols (GrTP) in the colon of the multidrug resistance targeted mutation (Mdr1a(-/-)) mouse model of IBD. Insights into mechanisms responsible for this reduction in inflammation were gained using transcriptome and proteome analyses. Mice were randomly assigned to an AIN-76A (control) or GrTP-enriched diet. At 21 or 24 weeks of age, a colonic histological injury score was determined for each mouse, colon mRNA transcript levels were assessed using microarrays, and colon protein expression was measured using two-dimensional gel electrophoresis and liquid chromatography-mass spectrometry protein identification. Mean colonic histological injury score of GrTP-fed Mdr1a(-/-) mice was significantly lower compared to those fed the control diet. Microarray and proteomics analyses showed reduced abundance of transcripts and proteins associated with immune and inflammatory response and fibrinogenesis pathways, and increased abundance of those associated with xenobiotic metabolism pathways in response to GrTP, suggesting that its anti-inflammatory activity is mediated by multiple molecular pathways. Peroxisome proliferator-activated receptor-α and signal transducer and activator of transcription 1 appear to be two key molecules which regulate these effects. These results support the view that dietary intake of polyphenols derived from green tea can ameliorate intestinal inflammation in the colon of a mouse model of IBD, and are in agreement with studies suggesting that consumption of green tea may reduce IBD symptoms and therefore play a part in an overall IBD treatment regimen.

Effects of green tea polyphenols on iodide-induced autoimmune thyroiditis in nonobese diabetic mice

Because green tea polyphenols (GTPs) possess anti-inflammatory properties and are effective in inhibiting autoimmune diseases in experimental settings, we examined whether GTPs prevented the development of autoimmune thyroiditis in iodide-treated nonobese diabetic (NOD) mice, an animal model of Hashimoto's thyroiditis (HT). Mice were given 0.05% iodide water or iodide water supplemented with 0.2% GTPs for 8 weeks. GTPs administration led to an enhanced production of interleukin-10 by concanavalin A-stimulated splenocytes but did not interfere with thyroiditis development. Serum thyroxine levels were not influenced by GTPs. Our data suggest that administration of GTPs may not be an effective strategy for the prevention of HT.

Histological and biochemical markers of the liver of Wistar rats on subchronic oral administration of green tea

Background:

Few articles have linked the consumption of green tea to certain liver diseases but several articles have disputed these assertions and the consumption of green tea has been on the increase.

Aims:

The effects of oral administration of green tea on the liver of Wistar rats were studied in order to compare biochemical findings with histological findings.

Materials and Methods:

36 male and female Wistar albino rats were grouped into 6, consisting of 6 rats in each group. They were given 1%, 2%, 3%, 4% and 5% concentration of green tea in tap water for 42 days. The 6^th group was on normal diet and received 0% of the tea. Their blood samples were analyzed for total and conjugated bilirubin, total protein, albumin, globulin, alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase. The liver tissues were also processed for histological examination.

Results:

The liver tissues were essentially normal and similar to the control tissues. The biochemical parameters studied were also normal and similar to the results obtained from the control animals.

Conclusion:

Sub chronic consumption of green tea has no injurious effects on the liver of Wistar rats.

Epigallocatechin gallate, a green tea phytochemical, attenuates alcohol-induced hepatic protein and lipid damage

ABSTRACT Oxidative damage to cellular constituents is one of the major mechanisms of alcoholic liver injury, and administration of antioxidants ameliorates alcoholic liver disease. The present study investigated the influence of (-) epigallocatechin gallate (EGCG), a major polyphenol component of green tea, on oxidant-antioxidant balance, protein, and lipid damage in liver of rats fed ethanol. Chronic ethanol administration (6 g/kg/day x 60 days) caused liver damage that was manifested by excessive formation of lipid peroxidation end products such as thiobarbituric acid-reactive substances (TBARS), lipid hydroperoxides (LHP), and conjugated dienes (CD) accompanied by a reduction in enzymic and non-enzymic antioxidant levels. Further, ethanol caused a rise in protein carbonyl formation and loss of protein thiol groups. Ethanol-fed rats exhibited increased staining for the presence of 4-hydroxynonenal (4-HNE), 3-nitrotyrosine (3-NT), and 2,4-dinitrophenol (DNP) protein adducts in liver. The detrimental effects of ethanol were alleviated upon simultaneous treatment with EGCG (100 mg/kg/day) for the last 30 days of alcohol feeding. These findings show that EGCG ameliorates protein and lipid damage induced by the hepatotoxin, ethanol.

Green tea polyphenol epigallocatechin-3-gallate shows therapeutic antioxidative effects in a murine model of colitis

BACKGROUND AND AIMS

Leukocyte infiltration, up-regulation of proinflammatory cytokines and severe oxidative stress caused by increased amounts of reactive oxygen species are characteristics of inflammatory bowel disease. The catechin (2R,3R)-2-(3,4,5-Trihydroxyphenyl)-3,4-dihydro-1(2H)-benzopyran-3,5,7-triol-3-(3,4,5-trihydroxybenzoate), named epigallocatechin-3-gallate, EGCG, has been demonstrated to exert anti-inflammatory and antioxidative properties, reducing reactive oxygen species in the inflamed tissues. The aim of this study was to evaluate the therapeutic effects of EGCG in a murine model of colitis induced by oral administration of dextran sodium sulfate.

METHODS

Mice received a daily oral administration of 6.9 mg/kg body weight EGCG or Piper nigrum (L.) alkaloid (2E,4E)-5-(1,3-benzodioxol-5-yl)-1-piperidin-1-ylpenta-2,4-dien-1-one, named piperine (2.9 mg/kg body weight) or the combination of the both - piperine was used in this combination to enhance the bioavailability of EGCG.

RESULTS

In vivo data revealed the combination of EGCG and piperine to significantly reduce the loss of body weight, improve the clinical course and increase overall survival in comparison to untreated groups. The attenuated colitis was associated with less histological damages to the colon and reduction of tissue concentrations of malondialdehyde, the final product of lipid peroxidation. Neutrophils accumulation indicator myeloperoxidase was found to be reduced in colon tissue, while antioxidant enzymes like superoxide dismutase and glutathione peroxidase showed an increased activity. In vitro, the treatment with EGCG plus piperine enhanced the expression of SOD as well as GPO and also reduced the production of proinflammatory cytokines.

CONCLUSION

These data support the concept of anti-inflammatory properties of EGCG being generally beneficial in the DSS-model of colitis, an effect that may be mediated by its strong antioxidative potential.

Green tea consumption: an alternative approach to managing oral lichen planus

Oral lichen planus (OLP) is a T-cell-mediated inflammatory autoimmune disease, whose pathogenesis includes both antigen-specific and non-specific mechanisms. Antigen-specific mechanisms in OLP consist of antigen presentation, lymphocyte activation, proliferation and migration as well as keratinocyte apoptosis mediated by CD8(+) cytotoxic T-cells, whereas non-specific mechanisms include mast cell degranulation and matrix metalloproteinase (MMP) activation in OLP lesions. Deficient antigen-specific transforming growth factor-β (TGF-β)-mediated immunosuppression may also contribute to the pathogenesis of OLP. In addition, OLP is considered to be a potentially malignant disorder with a malignant transformation rate of 0-5.3%. Green tea, especially epigallocatechin-3-gallate, possesses anti-inflammatory and chemopreventive properties. It can inhibit antigen presentation, T-cell activation, proliferation and migration, keratinocyte apoptosis, nuclear factor-kappaB (NF-кB) activation and MMP-9 activity, as well as regulated on activation, normal T-cell expressed and secreted (RANTES) expression, and can modulate the imbalance between TGF-β and interferon-γ signaling, all of which are involved in the pathogenesis of OLP. Thus, our hypothesis is that green tea consumption may decrease OLP incidence and provide a neoteric, nontoxic and inexpensive therapeutic strategy for OLP. Furthermore, green tea might be a possible agent for preventing malignancies in OLP.

Alternative medicines as emerging therapies for inflammatory bowel diseases

Inflammatory bowel disease (IBD) can be divided into two major categories, ulcerative colitis (UC) and Crohn disease (CD). While the main cause(s) of IBD remain unknown, a number of interventional and preventive strategies have been proposed for use against CD and UC. Many reports have focused on the use of alternative natural medicines as potential therapeutic interventions in IBD patients with minimal side effects. While the use of alternative medicines may be effective in IBD patients that are refractory to corticosteroids or thiopurins, alternative treatment strategies are limited and require extensive clinical testing before being optimized for use in patients.

Epigallocatechin-3-gallate ameliorates experimental autoimmune encephalomyelitis by altering balance among CD4+ T-cell subsets

The green tea component epigallocatechin-3-gallate (EGCG) may be beneficial in autoimmune diseases; however, the underlying mechanisms are not well understood. In this study, we determined the effect of EGCG on the development of experimental autoimmune encephalomyelitis, an animal model for human multiple sclerosis, and the underlying mechanisms. Female C57BL/6 mice were fed EGCG (0%, 0.15%, 0.3%, and 0.6% in diet) for 30 days and then immunized with specific antigen myelin oligodendrocyte glycoprotein 35-55. EGCG dose dependently attenuated clinical symptoms and pathological features (leukocyte infiltration and demyelination) in the central nervous system and inhibited antigen-specific T-cell proliferation and delayed-type hypersensitivity skin response. We further showed that EGCG reduced production of interferon-γ, IL-17, IL-6, IL-1β, and tumor necrosis factor-α; decreased types 1 and 17 helper T cells (Th1 and Th17, respectively); and increased regulatory T-cell populations in lymph nodes, the spleen, and the central nervous system. Moreover, EGCG inhibited expression of transcription factors T-box expressed in T cells and retinoid-related orphan receptor-γt, the specific transcription factor for Th1 and Th17 differentiation, respectively; the plasma levels of intercellular adhesion molecule 1; and CCR6 expression in CD4(+) T cells. These results indicate that EGCG may attenuate experimental autoimmune encephalomyelitis autoimmune response by inhibiting immune cell infiltration and modulating the balance among pro- and anti-autoimmune CD4(+) T-cell subsets. Thus, we identified a novel mechanism that underlies EGCG's beneficial effect in autoimmune disease.

Beneficial effects of THSG on acetic acid-induced experimental colitis: involvement of upregulation of PPAR-γ and inhibition of the Nf-Κb inflammatory pathway

The polyphenolic compound 2,3,5,4′-tetrahydroxystilbene-2-O-beta-D-glucoside (THSG) has been shown to possess anti-inflammatory effects. Here, we examined the effects of THSG on experimental mice with colitis induced by acetic acid and whether the underlying mechanisms were associated with the PPAR-γ and NF-κB pathways. Mice were randomized into six equal groups: normal, colitis model, THSG (10, 30, 60 mg·kg⁻¹) and mesalazine. The mice were administered 10, 30, 60 mg·kg⁻¹ THSG or 100 mg·kg⁻¹ mesalazine or saline once daily by intragastric administration for 7 days after induction of colitis by acetic acid irrigation. THSG dramatically attenuated acetic acid-induced colon lesions, including reversing the body weight loss and improving histopathological changes. THSG apparently decreased the increase of malondialdehyde (MDA) which is a marker of lipid peroxidation. THSG appears to exert its beneficial effects on acetic acid-induced experimental colitis through upregulation of PPAR-γ mRNA and protein levels and inhibition of the NF-κB pathway, which in turn decreases the protein overexpression of the downstream inflammatory mediators TNF-α, IL-6 and COX-2. The effect of THSG 60 mg·kg⁻¹ on PPAR-γ mRNA expression was higher than that of mesalazine. THSG may thus be a promising new candidate or lead compound for the treatment of IBD.

Immunomodulatory properties of vitamins, flavonoids and plant oils and their potential as vaccine adjuvants and delivery systems

INTRODUCTION

During the past century, vaccinologists have attempted to mimic pathogens in their immune-enhancing capacity. This led to the development of life-saving vaccines based on live attenuated viruses, bacteria and toxoids. Hence, intense research in vaccine adjuvant discovery has focused on toll like receptors, mutant toxins and viral and bacterial vectors. Nutritive components such as vitamins and select polyphenols also possess immunomodulating properties without the potential toxic and adverse side effects of agents that mimic danger signals.

AREAS COVERED

This review pertains to immunomodulatory properties of nutritive components, that is vitamins A, C, D, E, flavonoids and plant oils, as potential vaccine adjuvants and delivery systems, covering Pubmed publication searches from 1980 through 2011.

EXPERT OPINION

This relatively unexplored field of the potential of nutritive components as vaccine adjuvants holds great promise to promote the development of effective and above all safe vaccines. Hence the future focus should be placed on enhancing their efficacy, mainly through novel approaches in designing structural derivatives, formulations, delivery systems and routes of administration. As safety has been the major issue in development of novel vaccines, this new approach will probably result in new discoveries in designing safe and effective vaccines.