Proanthocyanidins from grape seeds inhibit UV-radiation-induced immune suppression in mice: detection and analysis of molecular and cellular targets

Oxidative stress, hormones, and effects of natural antioxidants on intestinal inflammation in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic, relapsing gastrointestinal (GI) disorder characterized by intestinal inflammation. The etiology of IBD is multifactorial and results from a complex interplay between mucosal immunity, environmental factors, and host genetics. Future therapeutics for GI disorders, including IBD, that are driven by oxidative stress require a greater understanding of the cellular and molecular mechanisms mediated by reactive oxygen species (ROS). In the GI tract, oxidative stressors include infections and pro-inflammatory responses, which boost ROS generation by promoting the production of pro-inflammatory cytokines. Nuclear factor kappa B (NF-κB) and nuclear factor erythroid 2-related factor 2 (Nrf2) represent two important signaling pathways in intestinal immune cells that regulate numerous physiological processes, including anti-inflammatory and antioxidant activities. Natural antioxidant compounds exhibit ROS scavenging and increase antioxidant defense capacity to inhibit pro-oxidative enzymes, which may be useful in IBD treatment. In this review, we discuss various polyphenolic substances (such as resveratrol, curcumin, quercetin, green tea flavonoids, caffeic acid phenethyl ester, luteolin, xanthohumol, genistein, alpinetin, proanthocyanidins, anthocyanins, silymarin), phenolic compounds including thymol, alkaloids such as berberine, storage polysaccharides such as tamarind xyloglucan, and other phytochemicals represented by isothiocyanate sulforaphane and food/spices (such as ginger, flaxseed oil), as well as antioxidant hormones like melatonin that target cellular signaling pathways to reduce intestinal inflammation occurring with IBD.

Proanthocyanidins: A novel approach to Henoch‑Schonlein purpura through balancing immunity and arresting oxidative stress via TLR4/MyD88/NF‑κB signaling pathway (Review)

Henoch-Schonlein purpura (HSP), a recurrent and immunoglobulin (Ig)A-mediated vasculitis, presents not only as skin lesions but also as systemic involvement that can be life-threatening. Although the etiology of HSP remains unknown, immune imbalance and oxidative stress (OS) are primary contributors to its pathogenesis, alongside the abnormal activation of Toll-like receptor (TLR)/myeloid differentiation primary response gene 88 (MyD88)/nuclear factor-κB (NF-κB) pathway. TLRs, especially TLR4, stimulate downstream signaling molecules such as NF-κB and proinflammatory cytokines, which are released when TLRs combine with the key adapter molecule MyD88. This leads to the activation of T helper (Th) cell 2/Th17 and overproduction of reactive oxygen species (ROS). The function of regulatory T (Treg) cells is suppressed in the process. Th17/Treg imbalance then produces various inflammatory cytokines to promote proliferation and differentiation of B cells and the secretion of antibodies. IgA is secreted, and it binds to vascular endothelial surface receptors where the complex induces injury of the vascular endothelial cells. Additionally, excessive ROS creates OS that leads to an inflammatory response and vascular cell apoptosis or necrosis, thereby contributing to vascular endothelial damage and HSP occurrence. Proanthocyanidins are active compounds naturally enriched in fruits, vegetables and plants. Proanthocyanidins have diverse properties, including anti-inflammatory, antioxidant, antibacterial, immunoregulatory, anticarcinogenic and vascular protective effects. Proanthocyanidins are used in the management of various diseases. Proanthocyanidins regulate T cells, equilibrate immunity and arrest OS by inhibiting the TLR4/MyD88/NF-κB signaling pathway. Considering the pathogenesis of HSP and the properties of proanthocyanidins, the present study hypothesized that these compounds may potentially lead to HSP recovery through modulating the immune equilibrium and preventing OS by inhibiting the TLR4/MyD88/NF-κB pathway. To the best of our knowledge, however, little is known about the positive effects of proanthocyanidins against HSP. The present review summarizes the potential of proanthocyanidins to treat HSP.

Tackling the Future Pandemics: Broad-Spectrum Antiviral Agents (BSAAs) Based on A-Type Proanthocyanidins

A-type proanthocyanidins (PAC-As) are plant-derived natural polyphenols that occur as oligomers or polymers of flavan-3-ol monomers, such as (+)-catechin and (-)-epicatechin, connected through an unusual double A linkage. PAC-As are present in leaves, seeds, flowers, bark, and fruits of many plants, and are thought to exert protective natural roles against microbial pathogens, insects, and herbivores. Consequently, when tested in isolation, PAC-As have shown several biological effects, through antioxidant, antibacterial, immunomodulatory, and antiviral activities. PAC-As have been observed in fact to inhibit replication of many different human viruses, and both enveloped and non-enveloped DNA and RNA viruses proved sensible to their inhibitory effect. Mechanistic studies revealed that PAC-As cause reduction of infectivity of viral particles they come in contact with, as a result of their propensity to interact with virion surface capsid proteins or envelope glycoproteins essential for viral attachment and entry. As viral infections and new virus outbreaks are a major public health concern, development of effective Broad-Spectrum Antiviral Agents (BSAAs) that can be rapidly deployable even against future emerging viruses is an urgent priority. This review summarizes the antiviral activities and mechanism of action of PAC-As, and their potential to be deployed as BSAAs against present and future viral infections.

Hybrid Nanoparticles of Proanthocyanidins from Uncaria tomentosa Leaves: QTOF-ESI MS Characterization, Antioxidant Activity and Immune Cellular Response

Previous studies in Uncaria tomentosa have shown promising results concerning the characterization of polyphenols with leaves yielding more diverse proanthocyanidins and higher bioactivities values. However, the polyphenols-microbiota interaction at the colonic level and their catabolites avoid the beneficial effects that can be exerted by this medicinal plant when consumed. In this regard, a new generation of hybrid nanoparticles has demonstrated improvements in natural compounds’ activity by increasing their bioavailability. In this line, we report a detailed study of the characterization of a proanthocyanidin-enriched extract (PA-E) from U. tomentosa leaves from Costa Rica using UPLC-QTOF-ESI MS. Moreover, two types of hybrid nanoparticles, a polymeric-lipid (F-1) and a protein-lipid (F-2) loaded with PA-E were synthesized and their characterization was conducted by dynamic light scattering (DLS), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FT-IR), high-resolution transmission electron microscopy (HR-TEM), and encapsulation efficiency (%EE). In addition, in vitro release, antioxidant activity through 2,2-diphenyl-1-picrylhidrazyl (DPPH) as well as in vivo delayed-type hypersensitivity (DTH) reaction was evaluated. Results allowed the identification of 50 different compounds. The PA-E loaded nanoparticles F-1 and F-2 achieved encapsulation efficiency of ≥92%. The formulations exhibited porosity and spherical shapes with a size average of 26.1 ± 0.8 and 11.8 ± 3.3 nm for F-1 and F-2, respectively. PA-E increased its release rate from the nanoparticles compared to the free extract in water and antioxidant activity in an aqueous solution. In vivo, the delayed-type hypersensitive test shows the higher immune stimulation of the flavan-3-ols with higher molecular weight from U. tomentosa when administered as a nanoformulation, resulting in augmented antigen-specific responses. The present work constitutes to our knowledge, the first report on these bioactivities for proanthocyanidins from Uncaria tomentosa leaves when administrated by nanosystems, hence, enhancing the cellular response in mice, confirming their role in immune modulation.

An Emerging Role of Proanthocyanidins on Psoriasis: Evidence from a Psoriasis-Like Mouse Model

Background

Psoriasis is an immune-mediated, chronic inflammatory disease, and genetic, immune, oxidative stress (OS), and environmental factors are all thought to contribute to its occurrence. Proanthocyanidins (PCs) are natural flavonoids consisting of catechins and epicatechins which have anti-inflammatory and anti-OS activities. PCs have been widely used to treat various diseases, but reports regarding psoriasis are rare.

Objective

To investigate the therapeutic effect and potential mechanisms of action of PCs in a psoriasis-like mouse model.

Methods

Thirty male BALB/c hairless mice were assigned to six groups (n = 5): normal, model, low-dose PCs, medium-dose PCs, high-dose PCs, and control groups. The final five groups were dorsally exposed to 5% imiquimod (IMQ) cream once a day for 6 consecutive days, while the normal group received no intervention. Following the first day of IMQ application, mice in the PC-treated group were dosed with different amounts of PCs daily by oral gavage for six days, whereas mice in the control group received normal saline in the same way. One week later, skin lesions were evaluated by the severity of scoring system based on psoriasis area and severity index (PASI), and pathological alterations were assessed by hematoxylin-eosin (HE) staining. Indicators of inflammation or OS, such as interleukin- (IL-) 17, IL-23, phosphorylated-phosphatidylinositol 3-kinase (p-PI3K), phosphorylated-signal transducer and activator of transcription 3 (p-STAT3), superoxide dismutase (SOD), glutathione (GSH), malondialdehyde (MDA), catalase (CAT), vascular endothelial growth factor (VEGF), inducible nitric oxide synthase (iNOS), reactive oxygen species (ROS), and heme oxygenase-1 (HO-1), were determined by ELISA, RT-PCR, western blot, and immunohistochemistry (IHC) analysis.

Results

IMQ administration induced the formation of large dark red plaques with thickly layered scales on the dorsal skin of mice; nevertheless, the lesions were substantially alleviated by PC administration. Histopathological alterations were observed in both model and control groups with epidermal hyperkeratosis, granulosa layer thinning, acanthosis, downward extension of rete ridges, dermal papillae expansion, capillary hyperplasia, and infiltration by inflammatory cells around blood vessels. These pathological changes, however, were restored by a range of doses of PCs, high-dose PCs in particular. Different doses of PCs significantly lowered the spleen index, levels of inflammatory or oxidative proteins (IL-17, IL-23, MDA, ROS, p-PI3K, and p-STAT3), and the mRNA expression of Il-17, Il-23, Vegf, and iNos. Protein and mRNA levels of anti-OS and anti-inflammatory biomarkers, including SOD, CAT, GSH, and HO-1, greatly increased after PC treatment, especially at the highest dose.

Conclusions

Our findings reveal that PCs ameliorate psoriasis-like symptoms, suppressing the inflammatory response and mitigating OS damage in an IMQ-induced psoriasis-like mouse model. These effects are probably related to the inactivation of STAT3 and PI3K and activation of HO-1 signaling.

Green extraction of bioactive compounds from wine lees and their bio-responses on immune modulation using in vitro sheep model

The objective of this study was to apply microwave-assisted extraction using green solvents starting from 3 different wine (white, rosé, and red) lees and to test their bio-response on sheep peripheral blood mononuclear cells proliferation, Bax/Bcl-2 ratio, and cytokines secretion. Wine lees (WL) of local organic farming from white wine, produced with Trebbiano cultivar, rosé and red wine, made with Nero di Troia cultivar, were collected. The WL were subjected to microwave-assisted extraction using 2 green solvents (water and ethanol) in 3 different combinations (water; water/ethanol 1:1 vol/vol; ethanol) with a dry matter-to-solvent ratio of 1:40 (wt/vol) at 4 temperature levels: 50, 100, 150, and 200°C. Sodium carbonate Na₂CO₃ (2 mmol/g of dry weight of lees) was used for increasing the polyphenol extraction yield. A total number of 6 extracts, 2 for each kind of WL investigated, according to their total phenolic content and in vitro antioxidant capacity, were selected to be tested on sheep peripheral blood mononuclear cells, as an animal model. All the WL extracts demonstrated a strong antiproliferative action. On the contrary, the cytokines' profile was mainly dependent on the different winemaking derived WL and the extraction solvent combination procedures. Red WL extract obtained by a combination of water/Na₂CO₃ and tested at 0.8 mg/mL, resulted in an increase of both IL-6 secretion and Bax/Bcl-2 ratio. Data from the present study demonstrated that WL extracts derived from different winemaking and solvent extraction could have a bimodal action on control of inflammatory mediated damage and highlighted the importance for further studies aimed at applying the biorefinery process on by-products to increase their economic value and exploit new derived bioactive compound.

The Challenging Melanoma Landscape: From Early Drug Discovery to Clinical Approval

Melanoma is recognized as the most dangerous type of skin cancer, with high mortality and resistance to currently used treatments. To overcome the limitations of the available therapeutic options, the discovery and development of new, more effective, and safer therapies is required. In this review, the different research steps involved in the process of antimelanoma drug evaluation and selection are explored, including information regarding in silico, in vitro, and in vivo experiments, as well as clinical trial phases. Details are given about the most used cell lines and assays to perform both two- and three-dimensional in vitro screening of drug candidates towards melanoma. For in vivo studies, murine models are, undoubtedly, the most widely used for assessing the therapeutic potential of new compounds and to study the underlying mechanisms of action. Here, the main melanoma murine models are described as well as other animal species. A section is dedicated to ongoing clinical studies, demonstrating the wide interest and successful efforts devoted to melanoma therapy, in particular at advanced stages of the disease, and a final section includes some considerations regarding approval for marketing by regulatory agencies. Overall, considerable commitment is being directed to the continuous development of optimized experimental models, important for the understanding of melanoma biology and for the evaluation and validation of novel therapeutic strategies.

Impact of grape pomace flour (GPF) on immunity and immune-antioxidant-anti-inflammatory genes expression in Labeo rohita against Flavobacterium columnaris

This study evaluates the effects of dietary inclusion of grape pomace flour (GPF) on growth, antioxidant, anti-inflammatory, innate-adaptive immunity, and immune genes expression in Labeo rohita against Flavobacterium columnaris. In both normal and challenged fish the growth rate, hematology and biochemical parameters significantly increased when fed with 200 and 300 mg GPF enriched diets; similarly the activities of antioxidants and innate-adaptive immune parameters, such as malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione (GSH), phagocytic (PC), respiratory burst (RB), alternative pathway complement (ACP), lysozyme (Lyz), and total immunoglobulin M (IgM) significantly increased in both groups. Similarly, the immune, antioxidant, and anti-inflammatory-related gene mRNA expression was significantly up-regulated in head kidney (HK) tissues. The challenged fish fed without GPF always exhibited lower values of all the studied parameters. The results indicate that both normal and challenged fish treated with 200 mg GPF inclusion diet had significantly enhanced growth rate, antioxidant status, and immune defense mechanisms than with 300 mg GPF diet in L. rohita against F. columnaris.

Proanthocyanidins Should Be a Candidate in the Treatment of Cancer, Cardiovascular Diseases and Lipid Metabolic Disorder

The conventional view of using medicines as routine treatment of an intractable disease is being challenged in the face of extensive and growing evidence that flavonoids in foods, especially proanthocyanidins (PAs), can participate in tackling fatal diseases like cancer, cardiovascular and lipid metabolic diseases, both as a precautionary measure or as a dietary treatment. Although medical treatment with medicines will remain necessary in some cases, at least in the short term, PAs’ function as antioxidant, anti-inflammatory drugs, signal pathway regulators remain critical in many diseases. This review article demonstrates the physical and biological properties of PAs, summarizes the health benefits of PAs found by researchers previously, and shows the possibility and importance of being a dietary treatment substance.

Targeting vasculogenic mimicry by phytochemicals: A potential opportunity for cancer therapy

Vasculogenic mimicry (VM) is regarded as a process where very aggressive cancer cells generate vascular-like patterns without the presence of endothelial cells. It is considered as the main mark of malignant cancer and has pivotal role in cancer metastasis and progression in various types of cancers. On the other hand, resistance to the antiangiogenesis therapies leads to the cancer recurrence. Therefore, development of novel chemotherapies and their combinations is urgently needed for abolition of VM structures and also for better tumor therapy. Hence, identifying compounds that target VM structures might be superior therapeutic factors for cancers treatment and controlling the recurrence and metastasis. In recent times, naturally occurring compounds, especially phytochemicals have obtained great attention due to their safe properties. Phytochemicals are also capable of targeting VM structure and also their main signaling pathways. Consequently, in this review article, we illustrated key signaling pathways in VM, and the phytochemicals that affect these structures including curcumin, genistein, lycorine, luteolin, columbamine, triptolide, Paris polyphylla, dehydroeffusol, jatrorrhizine hydrochloride, grape seed proanthocyanidins, resveratrol, isoxanthohumol, dehydrocurvularine, galiellalactone, oxacyclododecindione, brucine, honokiol, ginsenoside Rg3, and norcantharidin. The recognition of these phytochemicals and their safety profile may lead to new therapeutic agents' development for VM elimination in different types of tumors.

Proanthocyanidins: A comprehensive review

Proanthocyanidins are condensed tannins with various pharmacological properties. These phytochemicals are considered as 'offense and defense molecules because of their human health benefits. The validation of their diverse health aspects, namely, antioxidant, anticancer, antidiabetic, neuroprotective, and antimicrobial has earned them repute in thermochemistry. Proanthocyanidins are oligo- or polymers of monomeric flavan-3-ols produced as an end product of flavonoid biosynthetic pathway. Agricultural wastes and food processing wastes contain immense amount of proanthocyanidins, exploitation of which can be a sustainable source of dietary supplements and functional ingredients. The current review article discusses recent developments in the health promoting properties of proanthocyanidins and the associated hurdles.

Targeting PRPK and TOPK for skin cancer prevention and therapy

Solar ultraviolet (sUV) irradiation is a major environmental carcinogen that can cause inflammation and skin cancer. The costs and morbidity associated with skin cancer are increasing, and therefore identifying molecules that can help prevent skin carcinogenesis is important. In this study, we identified the p53-related protein kinase (PRPK) as a novel oncogenic protein that is phosphorylated by the T-LAK cell-originated protein kinase (TOPK). Knockdown of TOPK inhibited PRPK phosphorylation and conferred resistance to solar-simulated light (SSL)-induced skin carcinogenesis in mouse models. In the clinic, acute SSL irradiation significantly increased epidermal thickness as well as total protein and phosphorylation levels of TOPK and PRPK in human skin tissues. We identified two PRPK inhibitors, FDA-approved rocuronium bromide (Zemuron^®) or betamethasone 17-valerate (Betaderm^®) that could attenuate TOPK-dependent PRPK signaling. Importantly, topical application of either rocuronium bromide or betamethasone decreased SSL-induced epidermal hyperplasia, neovascularization, and cutaneous squamous cell carcinoma (cSCC) development in SKH1 (Crl: SKH1-Hr^hr) hairless mice by inhibiting PRPK activation, and also reduced expression of the proliferation and oncogenesis markers, COX-2, cyclin D1, and MMP-9. This study is the first to demonstrate that targeting PRPK could be useful against sUV-induced cSCC development.

In vivo validation of the multicomponent powder (Vitachelox®) against the deposition of polluting ions

Purpose

The purpose of this in vivo study is to evaluate the acute clinical application of a multicomponent powder (Vitachelox^®), including three naturally occurring standardized extracts rich in polyphenols (grape seed extract, green tea extract, oak wood/bark extract), on healthy volunteers by measuring prevention of any metal deposition within the stratum corneum (SC) following a 6-h exposure period in a polluted environment.

Patients and methods

In this in vivo study, we evaluated the skin protective activity of the multicomponent powder formulated in a base emulsion compared to a relevant placebo cream. Using the tape stripping method, SC samples of face skin obtained from 30 healthy volunteers were compared following a 6-h exposure in a polluted area.

Results

No statistically significant variations on the amount of heavy metals were found in the samples of SC cells obtained from the hemi-faces treated with the multicomponent powder, with respect to baseline. On the contrary, a significantly higher concentration of heavy metals was found in the cells samples obtained from the hemi-faces treated with the placebo cream. In particular, an increased concentration of heavy metals superior to 100% were found for iron and zinc (+130.2% and +142.6%, respectively; p<0.001).

Conclusion

This in vivo study validates and extends previous in vitro findings, indicating that the multicomponent powder allows the prevention of any metal deposition within the SC following exposure in a polluted environment. Our results suggest that the test product could play an effective role in counteracting skin damages induced by air pollution.

Laricitrin ameliorates lung cancer-mediated dendritic cell suppression by inhibiting signal transducer and activator of transcription 3

Natural polyphenolic compounds of grapes and their seeds are thought to be therapeutic adjuvants in a variety of diseases, including cancer prevention. This study was carried out to investigate the effect of grape phenolic compounds on the regulation of cancer-mediated immune suppression. Laricitrin exhibits the greatest potential to ameliorate the suppressive effects of lung cancer on dendritic cells’ (DCs’) differentiation, maturation and function. Human lung cancer A549 and CL1-5 cells change the phenotype of DCs that express to high levels of IL-10 and prime T cells towards an immune suppression type-2 response (Th2). Laricitrin treatment stimulated DC differentiation and maturation in the condition media of cancer cells, a finding supported by monocyte marker CD14's disappearance and DC marker CD1a's upregulation. Laricitrin decreases expression of IL-10 in cancer-conditioned DCs, and subsequently switches CD4⁺ T cell response from Th2 to Th1 in vitro and in vivo. Reversal of laricitrin on lung cancer-induced DCs’ paralysis was via inhibiting the phosphorylation of signal transducer and activator of transcription 3 (STAT3). Laricitrin also potentiated the anticancer activity of cisplatin in mouse models. Thus, laricitrin could be an efficacious immunoadjuvant and have a synergistic effect when combined with chemotherapy.

Proanthocyanidins and hydrolysable tannins: occurrence, dietary intake and pharmacological effects

Tannins are a heterogeneous group of high MW, water-soluble, polyphenolic compounds, naturally present in cereals, leguminous seeds and, predominantly, in many fruits and vegetables, where they provide protection against a wide range of biotic and abiotic stressors. Tannins exert several pharmacological effects, including antioxidant and free radical scavenging activity as well as antimicrobial, anti-cancer, anti-nutritional and cardio-protective properties. They also seem to exert beneficial effects on metabolic disorders and prevent the onset of several oxidative stress-related diseases. Although the bioavailability and pharmacokinetic data for these phytochemicals are still sparse, gut absorption of these compounds seems to be inversely correlated with the degree of polymerization. Further studies are mandatory to better clarify how these molecules and their metabolites are able to cross the intestinal barrier in order to exert their biological properties. This review summarizes the current literature on tannins, focusing on the main, recently proposed mechanisms of action that underlie their pharmacological and disease-prevention properties, as well as their bioavailability, safety and toxicology.

LINKED ARTICLES

This article is part of a themed section on Principles of Pharmacological Research of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.11/issuetoc.

Crosstalk Among UV-Induced Inflammatory Mediators, DNA Damage and Epigenetic Regulators Facilitates Suppression of the Immune System

The suppression of the immune system by overexposure to ultraviolet (UV) radiation has been implicated in the initiation and progression of photocarcinogenesis. Numerous changes occur in the skin on UVB exposure, including the generation of inflammatory mediators, DNA damage, epigenetic modifications, and migration and functional alterations in the antigen-presenting dendritic cells. Although each of these alterations can elicit a cascade of events that have the potential to modulate immune sensitivity alone, there is emerging evidence that there is considerable crosstalk between these cascades. The development of an understanding of UV-induced changes in the skin that culminate in UV-induced immunosuppression, which has been implicated in the risk of nonmelanoma skin cancer, as a network of events has implications for the development of more effective chemopreventive strategies. In the current review article, we discuss the evidence of interactions between the various molecular targets and signaling mechanisms associated with UV-induced immunosuppression.

Effect of dietary supplementation of grape seed extract on the growth performance, lipid profile, antioxidant status and immune response of broiler chickens

Grape seed extracts (GSE) contain several beneficial bioactive constituents; therefore, can be utilized as a potential feed additive in broiler chickens. An experiment was conducted to investigate the effect of supplementation of broiler chicken diets with GSE as a natural antioxidant at levels of 125, 250, 500, 1000 and 2000 ppm on the growth performance, serum lipid profile, liver glutathione-reduced, thigh muscle malondialdehyde and humoral immune response against Newcastle disease virus vaccines. This experiment was performed during the life-span of chickens from 0 to 42 days of age. The results of broilers fed on diet supplemented by GSE were compared with those fed on the basal diet (control) or the basal diet supplemented by butylated hydroxytoluene as a synthetic antioxidant (BHT, 125 ppm). No significant differences were observed in the growth performance, percent livability, total lipid, high and very low-density lipoprotein cholesterols when the use of GSE or BHT were compared with the control. Total cholesterol and low-density lipoprotein cholesterol were significantly decreased after intake of GSE compared with BHT in the feed diet. The glutathione-reduced level in liver tissues was significantly increased by inclusion of GSE, but not by BHT. Inclusion of GSE or BHT decreased significantly the malondialdehyde level found in meat tissue. The antibody titer against Newcastle disease virus vaccines was significantly elevated in 28 and 35-day-old broiler chickens fed with a diet supplemented with GSE or BHT, the former providing a higher response. It can be concluded that GSE can be used as an effective natural antioxidant and immunostimulant agent in broiler chicken diets, and that 125 to 250 ppm can be considered as the optimum dosage.

Antioxidant therapy for treatment of inflammatory bowel disease: Does it work?

Oxidative stress (OS) is considered as one of the etiologic factors involved in several signals and symptoms of inflammatory bowel diseases (IBD) that include diarrhea, toxic megacolon and abdominal pain. This systematic review discusses approaches, challenges and perspectives into the use of nontraditional antioxidant therapy on IBD, including natural and synthetic compounds in both human and animal models. One hundred and thirty four papers were identified, of which only four were evaluated in humans. Some of the challenges identified in this review can shed light on this fact: lack of standardization of OS biomarkers, absence of safety data and clinical trials for the chemicals and biological molecules, as well as the fact that most of the compounds were not repeatedly tested in several situations, including acute and chronic colitis. This review hopes to stimulate researchers to become more involved in this fruitful area, to warrant investigation of novel, alternative and efficacious antioxidant-based therapies.

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Major biomarkers used for evaluation of antioxidant therapy were MPO, TBARS/MDA and glutathione levels.

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Challenges were identified for the yet poor use of antioxidant therapy in IBD.

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This review stimulates the investigation of alternative and efficacious antioxidant therapies.