Flavonoids protect colon against radiation induced colitis

Hesperidin attenuates radiation-induced ovarian failure in rats: Emphasis on TLR-4/NF-ĸB signaling pathway

Young women suffering from premature ovarian failure after radiotherapy carry a huge burden in the field of cancer therapy including reproductive loss, emotional stress, and physical troubles that reduce their long-term quality of life. Hesperidin (HSP) exhibited antioxidant, anti-inflammatory, and anti-apoptotic properties. HSP enhanced in vitro follicular maturation and preserved in vivo ovarian stockpile. In this research, the role of HSP in radiation-induced POF in rats was investigated besides ascertaining its underlying mechanisms. Female Sprague-Dawley rats were arbitrarily allocated into four groups: control-group, ϒ-irradiated-group (3.2 Gy once on the 7th day), HSP-group (100 mg/kg, orally for 10 days), and HSP/ϒ-irradiated-group (ϒ-radiation was applied one hour after HSP). At the end of experiment, the whole ovaries were collected for histological and biochemical analyses. Administration of HSP preserved the ovarian histoarchitecture and follicular stock, retained ovarian weight, and conserved serum estradiol and AMH levels following radiation exposure. HSP ameliorated the ovarian oxidative damage mediated by radiation through augmenting the activities of glutathione peroxidase, glutathione reductase, and catalase antioxidant enzymes. HSP exhibited remarkable anti-inflammatory activity by downregulating the expression of ovarian TLR-4, NF-ĸB, and TNF-α. Moreover, HSP suppressed the apoptotic machinery triggered by radiation by reducing p53 and Bax while increasing Bcl-2 mRNA expressions alongside diminishing caspase-3 expression. Additionally, HSP regulated estrous cycle disorder of irradiated rats and improved their reproductive capacity reflected by enhancing pregnancy outcomes. Therefore, HSP represents an appealing candidate as an adjunct remedy for female cancer patients during radiotherapy protocols owing to its antioxidant, anti-inflammatory, anti-apoptotic, and hormone-regulatory effects.

The chemical composition, protective effect of Rheum officinale leaf juice and its mechanism against dextran sulfate sodium-induced ulcerative colitis

BACKGROUND

Rhubarb is widely distributed and cultivated worldwide, and its leaves presented antioxidant activity and could be used as food additive. However, the chemical ingredients, and protective effect of Rheum officinale leaf juice (JROL) on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) are still unclear.

PURPOSE

This paper sought to the characterization and functional properties of JROL, and explore the underlying mechanism on UC mice.

METHODS

UPLC-ESI-Q-TOF/MS and other analytical instruments were employed to determine the chemical ingredients of JROL. After inducing UC model using 3% DSS, multiple biological methods were used to evaluate its protective effect and the potential mechanism.

RESULTS

JROL is rich in proximate compositions and minerals and has high nutritional value, and contains reducing sugars, polysaccharides and pectin. Fifteen compounds were identified using UPLC-ESI-Q-TOF/MS. Among them, rutin has the highest content (2.22 %) in UPLC analysis. JROL presented protective effect on DSS-induced UC, and alleviated morphological alterations and ultra-structural feature of tissue, and the polysaccharides and flavonoids may contribute to its protective effect. JROL inhibited NF-κB/NLRP3 signaling pathway to alleviate inflammatory response, oxidative stress and intestinal injury by decreasing the expression of p-p65, p-IκBα, NLRP3, ASC, etc.. Moreover, it up-regulated the expression of tight junction proteins, and re-balanced the disturbance of gut microbiota to regulate the inflammatory response. Finally, a correlation among the inflammatory response, NF-κB/NLRP3 pathway and gut microbiota was established. Moreover, JROL presented the safety in the acute toxicity test.

CONCLUSION

JROL could be used as a potential new source for treating UC.

Predictive value of FCGBP expression for treatment response and survival in rectal cancer patients undergoing chemoradiotherapy

Despite neoadjuvant chemoradiotherapy (CRT) being the established standard for treating advanced rectal cancer, clinical outcomes remain suboptimal, necessitating the identification of predictive biomarkers for improved treatment decisions. Previous studies have hinted at the oncogenic properties of the Fc fragment of IgG binding protein (FCGBP) in various cancers; however, its clinical significance in rectal cancer remains unclear. In this study, we first conducted an analysis of a public transcriptome comprising 46 rectal cancer patients. Focusing on cell adhesion during data mining, we identified FCGBP as the most upregulated gene associated with CRT resistance. Subsequently, we assessed FCGBP immunointensity using immunohistochemical staining on 343 rectal cancer tissue blocks. Elevated FCGBP immunointensity correlated with lymph node involvement before treatment (p = 0.001), tumor invasion, and lymph node involvement after treatment (both p < 0.001), vascular invasion (p = 0.001), perineural invasion (p = 0.041), and reduced tumor regression (p < 0.001). Univariate analysis revealed a significant association between high FCGBP immunoexpression and inferior disease-specific survival, local recurrence-free survival, and metastasis-free survival (all p ≤ 0.0002). Furthermore, high FCGBP immunoexpression independently emerged as an unfavorable prognostic factor for all three survival outcomes in the multivariate analysis (all p ≤ 0.025). Enriched pathway analysis substantiated the role of FCGBP in conferring resistance to radiation. In summary, our findings suggest that elevated FCGBP immunoexpression in rectal cancer significantly correlates with a poor response to CRT and diminished patient survival. FCGBP holds promise as a valuable prognostic biomarker for rectal cancer patients undergoing CRT.

Elderberry diet enhances motor performance and reduces neuroinflammation-induced cell death in cerebellar ataxia rat models

Cerebellar ataxia (CA) is a condition in which cerebellar dysfunction results in movement disorders such as dysmetria, synergy and dysdiadochokinesia. This study investigates the therapeutic effects of elderberry (EB) diet on the 3-acetylpyridine-induced (3-AP) CA rat model. First, CA rat models were generated by 3-AP administration followed by elderberry diet treatment containing 2 % EB for 8 consecutive weeks. Motor performance, electromyographic activity and gene expression were then evaluated. The number of Purkinje neurons were evaluated by stereological methods. Immunohistochemistry for the microgliosis, astrogliosis and apoptosis marker caspase-3 was also performed. In addition, the morphology of microglia and astrocytes was assessed using the Sholl analysis method. The results showed that EB diet administration in a 3-AP ataxia model improved motor coordination, locomotor activity and neuro-muscular function, prevented Purkinje neurons degeneration, increased microglia and astrocyte complexity and reduced cell soma size. Moreover, EB diet administration decreased apoptosis in cerebellum of 3-AP ataxic model. In addition, elderberry diet treatment decreased the expression of inflammatory, apoptotic and necroptotic genes and increased the expression of antioxidant-related genes. The results suggest that the EB diet attenuates 3-AP-induced neuroinflammation leading to cell death and improves motor performance. Thus, the EB diet could be used as a therapeutic procedure for CA due to its neuroprotective effects.

Luteolin enhanced antioxidant capability and induced pyroptosis through NF-κB/NLRP3/Caspase-1 in splenic lymphocytes exposure to ammonia

During feeding process in intensive chicken farms, the prolonged exposure of chickens to elevated level of ammonia leads to substantial economic losses within poultry farming industry. Luteolin (Lut), known as its anti-inflammatory and antioxidant properties, possesses the ability to eliminate free radicals and enhance the activities of antioxidant enzymes, thus rendering it highly esteemed in production. The objective of this study was to examine the effects of Lut on antioxidant and anti-inflammatory responses of chicken splenic lymphocytes exposed to ammonia. In order to achieve this, we have replicated a protective model involving Lut against ammonia exposure in chicken splenic lymphocytes. The findings of the study indicated that Lut mitigated the elevation of lactate dehydrogenase (LDH), malondialdehyde (MDA), and reactive oxygen species (ROS) induced by ammonia poisoning. Additionally, Lut demonstrated an increase in the expression of antioxidant enzymes, namely superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Furthermore, Lut exhibited a protective effect on cell morphology and ultrastructure following exposure to ammonia. Moreover, Lut exhibited a reduction in the expression of heat shock proteins (HSPs) and inflammatory cytokines, which were found to be highly expressed in splenic lymphocytes after ammonia exposure. Additionally, Lut demonstrated the ability to inhibit the overexpression of pyroptosis-related genes and proteins (NLRP3 and Caspase-1) in splenic lymphocytes following ammonia exposure. Lut exerted an antioxidant effect on lymphocytes, counteracting elevated levels of oxidative stress following exposure to ammonia. Additionally, Lut had the potential to modulate the expression of HSPs, suppressed the inflammatory response subsequent to ammonia exposure, and influenced the expression of NLRP3 and Caspase-1, thereby mitigating pyroptosis induced by ammonia exposure. The exploration of this subject matter can elucidate the protective properties of Lut against NH4Cl-induced damage in chicken splenic lymphocytes, while also offer insights and experimental groundwork for the utilization of natural therapeutics in animal husbandry to prevent and treat ammonia-related conditions.

Colon-Targeted Release of Gel Microspheres Loaded with Antioxidative Fullerenol for Relieving Radiation-Induced Colon Injury and Regulating Intestinal Flora

Radiation-induced colitis is a serious clinical problem worldwide. However, the current treatment options for this condition have limited efficacy and can cause side effects. To address this issue, colon-targeted fullerenol@pectin@chitosan gel microspheres (FPCGMs) are developed, which can aggregate on colon tissue for a long time, scavenge free radicals generated in the process of radiation, and regulate intestinal flora to mitigate damage to colonic tissue. First, FPCGMs exhibit acid resistance and colon-targeted release properties, which reduce gastrointestinal exposure and extend the local colonic drug residence time. Second, fullerenol, which has a superior scavenging ability and chemical stability, reduces oxidative stress in colonic epithelial cells. Based on this, it is found that FPCGMs significantly reduce inflammation in colonic tissue, mitigated damage to tight junctions of colonic epithelial cells, and significantly relieved radiation-induced colitis in mice. Moreover, 16S ribosomal DNA (16S rDNA) sequencing results show that the composition of the intestinal flora is optimized after FPCGMs are utilized, indicating that the relative abundance of probiotics increases while harmful bacteria are inhibited. These findings suggest that it is a promising candidate for treating radiation-induced colitis.

Exploring Natural Products as Radioprotective Agents for Cancer Therapy: Mechanisms, Challenges, and Opportunities

Radiotherapy is an important cancer treatment. However, in addition to killing tumor cells, radiotherapy causes damage to the surrounding cells and is toxic to normal tissues. Therefore, an effective radioprotective agent that prevents the deleterious effects of ionizing radiation is required. Numerous synthetic substances have been shown to have clear radioprotective effects. However, most of these have not been translated for use in clinical applications due to their high toxicity and side effects. Many medicinal plants have been shown to exhibit various biological activities, including antioxidant, anti-inflammatory, and anticancer activities. In recent years, new agents obtained from natural products have been investigated by radioprotection researchers, due to their abundance of sources, high efficiency, and low toxicity. In this review, we summarize the mechanisms underlying the radioprotective effects of natural products, including ROS scavenging, promotion of DNA damage repair, anti-inflammatory effects, and the inhibition of cell death signaling pathways. In addition, we systematically review natural products with radioprotective properties, including polyphenols, polysaccharides, alkaloids, and saponins. Specifically, we discuss the polyphenols apigenin, genistein, epigallocatechin gallate, quercetin, resveratrol, and curcumin; the polysaccharides astragalus, schisandra, and Hohenbuehelia serotina; the saponins ginsenosides and acanthopanax senticosus; and the alkaloids matrine, ligustrazine, and β-carboline. However, further optimization through structural modification, improved extraction and purification methods, and clinical trials are needed before clinical translation. With a deeper understanding of the radioprotective mechanisms involved and the development of high-throughput screening methods, natural products could become promising novel radioprotective agents.

Polyphenols as Potential Protectors against Radiation-Induced Adverse Effects in Patients with Thoracic Cancer

Radiotherapy is one of the standard treatment approaches used against thoracic cancers, occasionally combined with chemotherapy, immunotherapy and molecular targeted therapy. However, these cancers are often not highly sensitive to standard of care treatments, making the use of high dose radiotherapy necessary, which is linked with high rates of radiation-induced adverse effects in healthy tissues of the thorax. These tissues remain therefore dose-limiting factors in radiation oncology despite recent technological advances in treatment planning and delivery of irradiation. Polyphenols are metabolites found in plants that have been suggested to improve the therapeutic window by sensitizing the tumor to radiotherapy, while simultaneously protecting normal cells from therapy-induced damage by preventing DNA damage, as well as having anti-oxidant, anti-inflammatory or immunomodulatory properties. This review focuses on the radioprotective effect of polyphenols and the molecular mechanisms underlying these effects in the normal tissue, especially in the lung, heart and esophagus.

Elderberry diet improves gut-brain axis dysfunction, neuroinflammation, and cognitive impairment in the rat model of irritable bowel syndrome

Irritable bowel syndrome (IBS) is related to a problem in the gut-brain axis. This experimental research aimed to shed light on the potential therapeutic application of elderberry (EB), which can work on the axis and get better the IBS symptoms. There were three groups (36 Sprague-Dawley rats) in this experiment, including control, IBS, and IBS with EB diet (IBS + EB). Making use of intracolonic instillation of 1 ml of 4% acetic acid for 30 s, IBS was induced. 7 days later, the EB extract (2%) was added to the diets of all animals for 8 weeks. Some histological, behavioral, and stereological techniques were used to detect the effects of EB on the gut and brain tissues. The findings showed that the EB diet improved locomotion and decreased anxiety-like behavior in the rat models of IBS. Moreover, the diet dropped the expression of TNF-α and increased mucosal layer thickness and the number of goblet and mast cells in colon tissue samples. In the hippocampal samples, administration of EB prevented astrogliosis and astrocyte reactivity. Although hippocampal and cortical neurons decreased markedly in the IBS group, EB prevented the drop in the number of neurons. Although lots of research is needed to elucidate the effectiveness of EB in IBS and its exact molecular mechanism, the result of this study showed that EB as an antioxidant and immune-modulatory agent could be a promising research target to prevent the impairment in the gut-brain axis, and could ameliorative classic IBS symptoms.

Fruits and their phytochemicals in mitigating the ill effects of ionizing radiation: review on the existing scientific evidence and way forward

Although helpful in treating cancer, exposure to ionizing radiation can sometimes cause severe side effects, negating its benefit. In addition to its use in clinics, a nontoxic radioprotective agent can also be beneficial in occupational settings where humans are occupationally exposed for prolonged periods to low doses of radiation. Scientific studies using laboratory animals have shown that the fruits Aegle marmelos, Capsicum annuum, Citrus aurantium, Citrullus lanatus, Crataegus microphylla, Eugenia jambolana, Emblica officinalis, Garcinia kola, Grewia asiatica, Hippophae rhamnoides, Malus baccata, Malpighia glabra or Malpighia emarginata, Mangifera indica, Prunus domestica, Prunus avium, Prunus armeniaca, Psoralea corylifolia, Punica granatum, Solanum lycopersicum, Terminalia chebula, Vaccinium macrocarpon, Vitis vinifera and Xylopia aethiopica, and the phytochemicals gallic acid, ellagic acid, quercetin, geraniin, corilagin, ascorbic acid, hesperetin, ursolic acid, lycopene, naringin, hesperidin, rutin, resveratrol, β-sitosterol, apigenin, luteolin, chlorogenic acid, caffeic acid, mangiferin, diosmin, ferulic acid, and kaempferol are effective in preventing radiation-induced ill effects. Clinical studies with Emblica officinalis and Punica granatum have also shown that fruits help mitigate radiation-induced mucositis, dermatitis, and cystitis. For the first time, the current review summarizes the beneficial effects of fruits and phytochemicals in mitigating radiation-induced damage, the underlying mechanisms and the existing lacunae for future studies to be undertaken for the benefit of humans and the nutraceutical and agri-based industries.

Biometabolites of Citrus unshiu Peel Enhance Intestinal Permeability and Alter Gut Commensal Bacteria

Flavanones in Citrus unshiu peel (CUP) have been used as therapeutic agents to reduce intestinal inflammation; however, the anti-inflammatory effects of their biometabolites remain ambiguous. Here, we identified aglycone-type flavanones, such as hesperetin and naringenin, which were more abundant in the bioconversion of the CUP than in the ethanol extracts of the CUP. We found that the bioconversion of the CUP induced the canonical nuclear factor-κB pathway via degradation of IκB in Caco-2 cells. To check the immune suppressive capacity of the aglycones of the CUP in vivo, we orally administered the bioconversion of the CUP (500 mg/kg) to mice for two weeks prior to the 3% dextran sulfate sodium treatment. The CUP-pretreated group showed improved body weight loss, colon length shortage, and intestinal inflammation than the control mice. We also found a significant decrease in the population of lamina propria Th17 cells in the CUP-pretreated group following dextran sodium sulfate (DSS) treatment and an increase in mRNA levels of occludin in CUP-treated Caco-2 cells. Pyrosequencing analysis revealed a decreased abundance of Alistipes putredinis and an increased abundance of Muribaculum intestinale in the feces of the CUP-pretreated mice compared to those of the control mice. Overall, these findings suggest that the pre-administration of CUP biometabolites may inhibit the development of murine colitis by modulating intestinal permeability and the gut microbiome.

1-Isobutanoil-2-isopropylisothiourea Phosphate, T1082: A Safe and Effective Prevention of Radiotherapy Complications in Oncology

The radioprotective effects of a new 1-isobutanoil-2-isopropylisothiourea derivative named T1082 are presented. Research methods included toxic characteristics, radioprotective activity (Till–McCulloch’s test and 30-day survival test) in γ-ray total-body-irradiated mice, and a clinical and histological study of the effect of T1082 on acute radiation skin reactions (RSR) in rats after a single or fractionated β-ray local irradiation. T1082 is more effective than its analogue, the NOS inhibitor T1023, at low concentrations and doses (1/12–1/8 LD₁₀), both parenterally and intragastrically. In this case, its therapeutic index (LD₅₀/ED₅₀) reaches 30, and the optimal radioprotective doses (ED_84–98—141–224 mg/kg) are an order less than the maximum tolerated doses—1/16–1/10 LD₁₀. These properties allowed T1082, at a low intragastrical dose (160 mg/kg; 1/14 LD10), to significantly limit the severity of acute RSR after single (40 Gy) and fractionated (78 Gy) β-ray irradiation. The results confirm T1082 as one of the safest emergency radioprotectors and indicate the prospects for its further development as a pharmacological agent for the prevention of RT complications.

Quercetin Prevents Radiation-Induced Oral Mucositis by Upregulating BMI-1

Radiation-induced oral mucositis is a major adverse event of radiotherapy. Severe oral mucositis may cause unwanted interruption in radiotherapy and reduce long-term survival in cancer patients receiving radiotherapy, but until now, there have been no effective options for preventing radiation-induced oral mucositis. Quercetin is a flavonoid that is widely found in food species and has anti-inflammatory, antioxidant, and anticancer activities. In this study, we investigated a new role of quercetin in preventing radiation-induced oral mucositis. Quercetin exerted preventive effects against radiation-induced oral mucositis induced by single-dose (25 Gy) ionizing radiation or fractionated ionizing radiation (8 Gy × 3) in C57BL/6 mice and maintained the proliferation ability of basal epithelial cells. Quercetin pretreatment alleviated reactive oxygen species generation, NF-κB pathway activation, and downstream proinflammatory cytokine production and reduced DNA double-strand breaks and cellular senescence induced by ionizing radiation. Quercetin also upregulated BMI-1 expression in oral epithelial cells and promoted ulcer repair. In addition, quercetin exerted similar radioprotective effects in irradiated primary cultured normal human keratinocytes, reduced reactive oxygen species generation and proinflammatory cytokine release, and promoted DNA double-strand break repair and wound healing by upregulating the expression of BMI-1, which is a polycomb group protein. Thus, quercetin can block multiple pathological processes of radiation-induced oral mucositis by targeting BMI-1 and may be a potential treatment option for preventing radiation-induced oral mucositis.

Phenolic Compounds Promote Diversity of Gut Microbiota and Maintain Colonic Health

The role of non-energy-yielding nutrients on health has been meticulously studied, and the evidence shows that a compound can exert significant effects on health even if not strictly required by the organism. Phenolic compounds are among the most widely studied molecules that fit this description; they are found in plants as secondary metabolites and are not required by humans for growth or development, but they can influence a wide array of processes that modulate health across multiple organs and systems. The lower gastrointestinal tract is a prime site of action of phenolic compounds, namely, by their effects on gut microbiota and colonic health. As with humans, phenolic compounds are not required by most bacteria but can be substrates of others; in fact, some phenolic compounds exert antibacterial actions. A diet rich in phenolic compounds can lead to qualitative and quantitative effects on gut microbiota, thereby inducing indirect health effects in mammals through the action of these microorganisms. Moreover, phenolic compounds may be fermented by the gut microbiota, thereby modulating the compounds bioactivity. In the colon, phenolic compounds promote anti-inflammatory, anti-oxidant and antiproliferative actions. The aim of the present review is to highlight the role of phenolic compounds on maintaining or restoring a healthy microbiota and overall colonic health. Mechanisms of action that substantiate the reported evidence will also be discussed.

The Ability of the Nitric Oxide Synthases Inhibitor T1023 to Selectively Protect the Non-Malignant Tissues

Previously, we showed that a nitric oxide synthase (NOS) inhibitor, compound T1023, induces transient hypoxia and prevents acute radiation syndrome (ARS) in mice. Significant efficacy (according to various tests, dose modifying factor (DMF)-1.6-1.9 against H-ARS/G-ARS) and safety in radioprotective doses (1/5-1/4 LD10) became the reason for testing its ability to prevent complications of tumor radiation therapy (RT). Research methods included studying T1023 effects on skin acute radiation reactions (RSR) in rats and mice without tumors and in tumor-bearing animals. The effects were evaluated using clinical, morphological and histological techniques as well as RTOG classification. T1023 administration prior to irradiation significantly limited the severity of acute RSR. This was due to a decrease in radiation alteration of the skin and underlying tissues, and the preservation of the functional activity of cell populations that are critical in the pathogenesis of radiation burn. The DMF values for T1023 for skin protection were 1.4-1.7. Moreover, its radioprotective effect was fully selective to normal tissues in RT models of solid tumors-T1023 reduced the severity of acute RSR and did not modify the antitumor effects of γ-radiation. The results indicate that T1023 can selectively protect the non-malignant tissues against γ-radiation due to hypoxic mechanism of action and potentiate opportunities of NOS inhibitors in RT complications prevention.

Elderberry diet ameliorates motor function and prevents oxidative stress-induced cell death in rat models of Huntington disease

Huntington's disease (HD) is an inherited neurodegenerative disorder which begins in the striatum and then spreads to other neural areas. Known as a progressive movement cognitive disorder, HD has no efficient therapy. Although the exact mechanism of HD is still unknown, several different etiological processes such as oxidative stress have been shown to play critical roles. Also, the current evidence indicates a strong correlation between immune activation and neural damage induced by neuroinflammatory and apoptotic agents in neurodegenerative disorders. Thus, natural products like Elderberry (EB) could be considered as a novel and potential therapeutic candidate for the treatment of this disease. In this study EB was added to the daily ration of ordinary rats for two months in order to ameliorate inflammatory and oxidative responses in rats injected with 3-nitropropionic acid (3-NP) in an experimental model of HD. Using Rotarod and electromyography setups, we showed that EB diet significantly recovered motor failure and muscle incoordination in 3-NP injected rats compared to the control group. Also, the molecular findings implied that EB diet led to a significant drop in 3-NP induced growth in caspase-3 and TNF-α concentration. The treatment also improved striatal antioxidative capacity by a significant reduction in ROS and a remarkable rise in GSH, which might be correlated with motor recovery in the tests. In sum, the findings demonstrate the advantages of EB treatment in the HD rat model with a score of beneficial anti-oxidative and anti-inflammatory effects.

Soy Isoflavones and Gastrointestinal Health

PURPOSE OF REVIEW

Soy isoflavones are known to have beneficial effects on several aspects of gastrointestinal physiological functions (contractility or motility, secretion, morphology, and barrier function). In this review, we discuss the effects of soy isoflavones on the overall gut function and inflammation and assess how these effects might be implicated in the treatment of several gut-related diseases.

RECENT FINDINGS

Soy isoflavones influence several key aspects of gastrointestinal health: improve basal intestinal secretion, alleviate inflammation, limit intestinal morphological damage, and improve epithelial barrier function in several clinically relevant murine models of gastrointestinal diseases. Dietary supplementation with isoflavones proves to be a key means to improve the overall gut function and health. Future mechanistic studies with isoflavone interventions will help treat clinically related diseases such as cystic fibrosis and inflammatory-related gut problems such as colitis and diabetes.

Ulcerative colitis: Gut microbiota, immunopathogenesis and application of natural products in animal models

Ulcerative colitis (UC) is an inflammatory bowel disease with increasing incidence in the world, especially in developing countries. Although knowledge of its pathogenesis has progressed over the last years, some details require clarification. Studies have highlighted the role of microbial dysbiosis and immune dysfunction as essential factors that may initiate the typical high-grade inflammatory outcome. In order to better understand the immunopathophysiological aspects of UC, experimental murine models are valuable tools. Some of the most commonly used chemicals to induce colitis are trinitrobenzene sulfonic acid, oxazolone and dextran sodium sulfate. These may also be used to investigate new ways of preventing or treating UC and therefore improving targeting in human studies. The use of functional foods or bioactive compounds from plants may constitute an innovative direction towards the future of alternative medicine. Considering the above, this review focused on updated information regarding the 1. gut microbiota and immunopathogenesis of UC; 2. the most utilized animal models of the disease and their relevance; and 3. experimental application of natural products, not yet tested in clinical trials.

An Overview of the Cellular Mechanisms of Flavonoids Radioprotective Effects

Considering the remarkable application of radiotherapy in the treatment and diagnosis of various diseases and even nuclear war, it is important to protect healthy tissues and people at risk from the radiation. Currently, there is no ideal and safe radioprotective agent available and we are seeing a great effort to find these agents from natural sources. Phenolic compounds, as well as flavonoid, are presented widely as the second metabolite in plants and they have been considered for investigation according to their benefits for human health, healing and preventing many disorders. The major bioactive benefits of flavonoids include antioxidant, anti-inflammatory, anti-tumor, anti-aging, anti-bacterial and viral, neuroprotection and radioprotective effects. Their lower toxicity and oral administration have made it suitable for radiotherapy patient, radiation, military forces, and even the general public. This review attempts to provide a summary of the main molecular mechanisms involved in flavonoid radio-protective effects. Data of these studies will provide a comprehensive perspective to flavonoids and can help to optimize their effects in radioprotection procedures.