Catechin protects against ketoprofen-induced oxidative damage of the gastric mucosa by up-regulating Nrf2 in vitro and in vivo

Colon-available mango (poly)phenols exhibit mitigating effects on the intestinal barrier function in human intestinal cell monolayers under inflammatory conditions

This study investigated the impact of in vivo available colon-mango (poly)phenols on stress-induced impairment of intestinal barrier function. Caco-2/HT29-MTX cells were incubated with six extracts of ileal fluid collected pre- and 4-8 h post-mango consumption before being subjected to inflammatory stress. (Poly)phenols in ileal fluids were analysed by UHPLC-HR-MS. Epithelial barrier function was monitored by measurement of trans-epithelial electrical resistance (TEER) and the production of selected inflammatory markers (interleukin-8 (IL-8) and nitric oxide (NO)) and the major mucin of the mucosal layer (MUC2). Post-mango intake ileal fluids contained principally benzoic acids, hydroxybenzenes and galloyl derivatives. There was a high interindividual variability in the levels of these compounds, which was reflected by the degree of variability in the protective effects of individual ileal extracts on inflammatory changes in the treated cell cultures. The 24 h treatment with non-cytotoxic doses of extracts of 4-8 h post-mango intake ileal fluid significantly reduced the TEER decrease in monolayers treated with the inflammatory cytomix. This effect was not associated with changes in IL-8 expression and secretion or claudine-7 expression. The mango derived-ileal fluid extract (IFE) also mitigated cytomix-dependent nitrite secretion, as a proxy of NO production, and the MUC2 reduction observed upon the inflammatory challenge. These insights shed light on the potential protective effect of mango (poly)phenols on the intestinal barrier exposed to inflammatory conditions.

Use of Callistemon citrinus as a gastroprotective and anti-inflammatory agent on indomethacin-induced gastric ulcers in obese rats

Background

Obesity leads to an elevated risk of developing gastrointestinal disease such as gastric ulcers. Callistemon citrinus leaf extract has shown antioxidant, antimicrobial, hepatoprotective, and chemoprotective effects against colon cancer. The aim of this study is to evaluate the gastroprotective effect of C. citrinus leaf extract on indomethacin-induced gastric ulcers in obese rats.

Methods

Gastric ulcers were induced in female obese Wistar rats using a single oral dose of indomethacin (IND). In the first stage, the rats were fed with a high fat sugar diet (HFSD) for 15 weeks to induce obesity and, at the same time, the diet of the other group of animals included daily administration of ethanolic C. citrinus leaf extract (250 mg/kg) in addition to HFSD. In the second stage, gastric ulcers were induced with IND (30 mg/kg). The gastroprotective activity of C. citrinus, the inflammatory enzyme activities, and cytokines in the stomach were determined.

Results

C. citrinus produced a reduction of gastric lesions caused by IND. Myeloperoxidase (MPO), cyclooxygenase-2 (COX-2), and 5-lipoxygenase (5-LOX) activities also decreased. Although inflammatory biomarkers such as TNFα, IL-6, AOPP, and leptin were significantly decreased by C. citrinus, adiponectin levels increased. Moreover, C. citrinus decreased weight gain and morphological and biochemical parameters.

Conclusion

The use of indomethacin in rats fed with a high fat-sugar diet increased gastric ulcers. Gastroprotective effect of C. citrinus in obese rats is attributed to the reduction of pro-inflammatory cytokines and the inflammatory enzymes.

The intestinal-level metabolic benefits of green tea catechins: Mechanistic insights from pre-clinical and clinical studies

BACKGROUND

The intestinal-level host-microbiota interaction has been implicated in the pathogenesis of chronic diseases. The current review is intended to provide a comprehensive insight into deciphering whether intestinal-level bioactivities mediate the overall metabolic health benefits of green tea catechins.

PURPOSE

We have comprehensively discussed pre-clinical and clinical evidences of intestinal-level changes in metabolism, microbiota, and metabolome due to catechin-rich green tea treatments, ultimately limiting metabolic diseases. Exclusive emphasis has been given to purified catechins and green tea, and discussions on extraintestinal mechanisms of metabolic health benefits were avoided.

METHODS

A literature search for relevant pre-clinical and clinical studies was performed in various online databases (e.g., PubMed) using specific keywords (e.g., catechin, intestine, microbiota). Out of all the referred literature, ∼15% belonged to 2021-2023, ∼51% were from 2011-2020, and ∼32% from 2000-2010.

RESULT

The metabolic health benefits of green tea catechins are indeed influenced by the intestinal-level bioactivities, including reduction of mucosal inflammation and oxidative stress, attenuation of gut barrier dysfunction, decrease in intestinal lipid absorption and metabolism, favorable modulation of mucosal nuclear receptor signaling, alterations of the luminal global metabolome, and mitigation of the gut dysbiosis. The results from the recent clinical studies support the pre-clinical evidences. The challenges and pitfalls of the currently available knowledge on catechin bioactivities have been discussed, and constructive directions to harness the translational benefits of green tea through future interventions have been provided.

CONCLUSION

The metabolism, metabolome, and microbiota at the intestinal epithelia play critical roles in catechin metabolism, pharmacokinetics, bioavailability, and bioactivities. Especially the reciprocal interaction between the catechins and the gut microbiota dictates the metabolic benefits of catechins.

Gastroprotective Activities of Aqueous and 80% Methanol Leaf Extracts of Stephania abyssinica (Quart.-Dill. and A. Rich.) Walp. (Menispermaceae) in Rats

Background

An ethnobotanical study showed that the leaf of Stephania abyssinica (S. abyssinica) is used for the treatment of gastritis, but there is no scientific investigation.

Objective

The aim of this study was to evaluate the gastroprotective activities of both aqueous and 80% methanol leaf extracts of S. abyssinica in experimental rats.

Methods

Decoction and maceration techniques were used to prepare aqueous and 80% methanol leaf extracts, respectively. The extracts were evaluated against pyloric ligation, indomethacin, and ethanol-induced gastric ulcer models at doses of 100, 200, and 400 mg/kg. Negative control received 2% tween 80, while positive controls received 20 mg/kg of omeprazole and 100 µg/kg of misoprostol. Parameters, such as ulcer index, gastric mucin content, gastric juice volume, pH, and free and total acidity were measured.

Results

In the pyloric ligation induced gastric ulcer model, all doses of both extracts significantly reduced the ulcer index and gastric juice volume, while doses of 200 and 400 mg/kg exhibited a significant increment in mucus content and gastric juice pH as well as decrease in free and total acidity as compared to negative control. In indomethacin and ethanol induced gastric ulcer models, pretreatment with both extracts significantly reduced the ulcer index and enhanced gastric mucin content in a dose-dependent manner. Phytochemical screening of both extracts showed the existence of flavonoids, phenols, tannins, saponins, alkaloids, and coumarins with high contents of phenols, flavonoids, and alkaloids in 80% methanol extract.

Conclusion

This study revealed that aqueous and 80% methanol leaf extracts of S. abyssinica possessed remarkable gastroprotective activities against experimentally induced gastric ulcer models, and this possibly justify the traditional use of S. abyssinica leaves to treat gastritis.

Cupuaçu extract protects the kidneys of diabetic rats by modulating Nrf2/NF-κB p65 and iNOS

Diabetes is characterized by increased levels of oxidative stress. Its suggested that extract of cupuaçu could improve the antioxidant system in diabetes. The aim was to evaluate the effect of EC on Nrf2/NF-κB p65 in normal and diabetic rats. Male, adult Wistar rats (9-week-old) were distributed in 4 groups: control (CTL) and diabetic (DM) who received water; CTLEC and DMEC who received 1 mL/day of EC (1 g/mL), via gavage for 8 consecutive weeks. The diabetes was inducted with a single intravenous dose of 45 mg/kg streptozotocin. Glycemia and body weight were measured at the beginning and end of the protocol, and the renal tissue was analyzed by Western blot for SOD-1, SOD-2, CAT, GSSG, Nrf2, NF-κB p65, iNOS and 3-NT. Glycemia was reduced in DMEC vs. DM after 8 weeks of EC treatment. There was no difference in body weight of DMEC vs. DM; however, DMEC vs. DM presented increased levels of CAT and Nrf2, with a significant reduction of NF-κB p65, iNOS and 3-NT. Therefore, we suggest that EC could be utilized as a complementary therapy to ameliorate the antioxidant profile via Nrf2 and to delay the evolution of diabetic complications in renal tissue by inflammatory pathway inhibition.

(-)-Epigallocatechin-3-Gallate Attenuates the Adverse Reactions Triggered by Selenium Nanoparticles without Compromising Their Suppressing Effect on Peritoneal Carcinomatosis in Mice Bearing Hepatocarcinoma 22 Cells

Increasing evidence shows that selenium and polyphenols are two types of the most reported compounds in tumor chemoprevention due to their remarkable antitumor activity and high safety profile. The cross-talk between polyphenols and selenium is a hot research topic, and the combination of polyphenols and selenium is a valuable strategy for fighting cancer. The current work investigated the combination anti-peritoneal carcinomatosis (PC) effect of selenium nanoparticles (SeNPs) and green tea (Camellia sinensis) polyphenol (-)-epigallocatechin-3-gallate (EGCG) in mice bearing murine hepatocarcinoma 22 (H22) cells. Results showed that SeNPs alone significantly inhibited cancer cell proliferation and extended the survival time of mice bearing H22 cells. Still, the potential therapeutic efficacy is accompanied by an approximately eighty percent diarrhea rate. When EGCG was combined with SeNPs, EGCG did not affect the tumor proliferation inhibition effect but eliminated diarrhea triggered by SeNPs. In addition, both the intracellular selectively accumulated EGCG without killing effect on cancer cells and the enhanced antioxidant enzyme levels in ascites after EGCG was delivered alone by intraperitoneal injection indicated that H22 cells were insensitive to EGCG. Moreover, EGCG could prevent SeNP-caused systemic oxidative damage by enhancing serum superoxide dismutase, glutathione, and glutathione peroxidase levels in healthy mice. Overall, we found that H22 cells are insensitive to EGCG, but combining EGCG with SeNPs could protect against SeNP-triggered diarrhea without compromising the suppressing efficacy of SeNPs on PC in mice bearing H22 cells and attenuate SeNP-caused systemic toxicity in healthy mice. These results suggest that EGCG could be employed as a promising candidate for preventing the adverse reactions of chemotherapy including chemotherapy-induced diarrhea and systemic toxicity in cancer individuals.

Apple (Malus domestica Borkh) leaves attenuate indomethacin-induced gastric ulcer in rats

Malus domestica Borkh, the apple tree, exhibited numerous pharmacological properties including antioxidant, neuroprotective, anti-inflammatory, anticancer and antimicrobial activities. The present work aimed to annotate the secondary metabolites from a butanol fraction of apple leaves (BLE), evaluate the gastro-protective and healing effects of this fraction against indomethacin-induced gastric ulcers in rats and to identify its mechanism of action. BLE (100, and 200 mg/kg) was orally administered in rats as an acute treatment against indomethacin-induced gastric ulcer in comparison with famotidine as reference anti-ulcer drug. The stomachs of rats were collected to determine the ulcer index, the preventive ratio, measure the activity of glutathione peroxidase (GPx), and estimate the expression of cyclooxygenase-2 (COX-2), and heat shock protein 70 (HSP70). Furthermore, we evaluated both inflammatory and oxidative stress markers in the gastric tissues. We also performed histopathological study of gastric mucosa using H&E stain and periodic Schiff base stain to evaluate both gastric injury scores and gastric mucus content respectively. Pretreatment with BLE markedly lowered the severity of gastric injury induced by indomethacin, decreased oxidative stress, inflammatory cytokines, and COX-2 expression in the examined gastric tissues. The gastric healing effect of BLE was associated with increased mucoglycoproteins, and HSP70 expression. Additionally, gastric healing effect of high dose of BLE was superior to that of famotidine in decreasing gastric injury scores, COX-2, inflammatory cytokines, lipid peroxidation and in increasing gastric mucin content, HSP70, and reduced glutathione. These findings indicate that BLE is effective in accelerating ulcer healing by boosting HSP70 expression, and decreasing COX-2 expression, oxidative stress, and gastric inflammation which might be related to the presence of 21 phytoconstituents.

Limonin ameliorates indomethacin-induced intestinal damage and ulcers through Nrf2/ARE pathway

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) can cause intestinal damage and ulcers and the incidence is increasing. Limonin plays an important role in the regulation of inflammatory diseases, but it has not been reported in the treatment of intestinal injury and ulcers.

METHODS

Indomethacin (INDO) induced intestinal injury and ulcer model in rats. The indexes related to intestinal injury were detected. Western blot and molecular docking techniques were used to detect the docking between Limonin and Nrf2. Next, ML385, an inhibitor of Nrf2/ARE signaling pathway, was applied to treat intestinal epithelial IEC-6 cells induced by INDO. And CCK8, Western blot, TUNEL, ELISA, DCFH-DA assay, kits, and immunofluorescence were conducted to detect cell activity, apoptosis, inflammatory response, oxidative stress, and tight junction again.

RESULTS

INDO can significantly induce intestinal ulcerative lesions in rats. Limonin could improve intestinal ulcerative lesions induced by INDO in rats. Limonin could reduce INDO-induced inflammatory response and oxidative stress in the small intestine of rats, and improve the intestinal barrier dysfunction induced by INDO. Limonin could dock with Nrf2 structure and activate Nrf2/ARE signaling pathway. ML385 could reverse the protective effect of Limonin against INDO-induced cell damage.

CONCLUSION

Limonin ameliorates INDO-induced intestinal damage and ulcers through Nrf2/ARE pathway.

Immunomodulatory Effects of Spherical Date Seed Pills Industrially Fabricated on RAW264.7 Cells

Dates have been demonstrated to display a variety of bioactivities and are rich in polyphenols. In this work, we assessed the underlying immunomodulatory effects of date seed polyphenol extracts that had been industrially encapsulated and fabricated into commercial pills in RAW264.7 macrophages using the NF-κB and Nrf2 signaling pathways. The outcomes showed that in RAW264.7 cells, the date seed pills effectively stimulated nuclear translocation of NF-E2-related factor 2 (Nrf2) and NF-κB, along with downstream cytokines (IL-1β, TNF-α, IL-6, and IFN-γ), ROS ratios, and SOD activity. It is interesting to note that the encapsulated pills activated Nrf2 nuclear translocation more effectively than the non-encapsulated ones did. Additionally, pills at 50 µg mL^-1 improved immunological responses, but pills at 1000 µg mL^-1 prevented macrophages from becoming inflamed. These results showed that the immunomodulatory effects were differently impacted by commercial date seed pills, a finding which was related to the large-scale manufacturing of the pills and the incubation concentrations used. These results also shed light on a new trend of using food byproducts as an innovative supplement.

Effect of 3-caffeoylquinic acid on growth performance, nutrient digestibility, and intestinal functions in weaned pigs

Phenolic acid like with the 3-caffeoylquini acid (3-CQA) is formed by caffeic acid and qunic acid. This study was conducted to explore the effect of 3-CQA on growth performance and intestinal functions in weaned pigs. A total of 180 weaned pigs were randomly allocated into five treatments with 6 replicate pens per treatment (6 pigs per pen). Pigs in the control group (CON) were fed with basal diet (BD), and the others in the experimental groups were fed with BD and supplemented with 12.5, 25, 50, and 100 mg/kg 3-CQA. On day 43, the blood sample-collected pigs in the CON and optimal-dose group (only based on growth performance) were picked, and housed in metabolism cages (a total of 12 pigs, N = 6). 3-CQA increased the feed efficiency from days 21 to 42 of the trial and throughout the trial (P < 0.05). 3-CQA increased the serum concentrations of total protein, albumin, and total cholesterol (P < 0.05). Moreover, 3-CQA supplementation at 25 mg/kg increased the apparent digestibility of DM, energy, and ash (P < 0.05). Interestingly, 3-CQA decreased the crypt depth but increased the ratio of villus height to crypt depth in the jejunum and ileum (P < 0.05). Moreover, 3-CQA also increased the activities of sucrase, lactase, and catalase in the jejunal mucosa, and increased the activities of alkaline phosphatase and superoxide dismutase in the ileal mucosa (P < 0.05). 3-CQA also increased the abundance of secretory immunoglobulin A in the ileal mucosa (P < 0.05). Importantly, 3-CQA not only elevated the expression levels of critical functional genes such as the zonula occludens-1 , occludin, solute carrier family 7 , and nuclear factor erythroid 2-related factor 2 (Nrf2) in the duodenum but also elevated the expression levels of divalent metal transporter-1 and Nrf2 in the jejunum (P < 0.05). These results suggested a positive effect of 3-CQA supplementation on the growth and intestinal functions of weaned pigs. The mechanisms of action may be associated with elevated anti-oxidant capacity and improved intestinal barrier functions.

Antioxidant, antihyperglycemic, and antihyperlipidemic properties of Chimonanthus salicifolius S. Y. Hu leaves in experimental animals: modulation of thioredoxin and glutathione systems, renal water reabsorption, and gut microbiota

Introduction

Excessive calorie intake and physical inactivity have dramatically increased nutrient overload-associated disease, becoming a global public health issue. Chimonanthus salicifolius S. Y. Hu (CHI) is a homology plant of food and medicine in China and shows several health benefits.

Methods

This work investigated the antioxidant activity, the alleviating effects, and the mechanism of action on diabetes and hyperlipidemia of CHI leaves.

Results and discussion

Results showed that CHI leaves infusion displayed in vitro antioxidant activity measured by ABTS and ferric reducing antioxidant power methods. In wild-type Kunming mice, CHI leaves infusion consumption activated the hepatic antioxidant enzymes, including glutathione reductase, glutathione S-transferase, glutathione peroxidase and thioredoxin reductase as well as thioredoxin reductase 1. In alloxan-induced type 1 diabetic mice, CHI leaves infusion ameliorated diabetic symptoms, including polyuria, polydipsia, polyphagia and hyperglycemia, in a dose-dependent and time-course manners. The mechanism involved CHI leaves up-regulating renal water reabsorption associated protein - urine transporter A1-and promoting the trafficking of urine transporter A1 and aquaporin 2 to the apical plasma membrane. Despite this, in high-fat diet-induced hyperlipidemic golden hamsters, CHI leaves powder did not significantly effect on hyperlipidemia and body weight gain. This might be attributed to CHI leaves powder increasing the calorie intake. Interestingly, we found that CHI leaves extract containing a lower dose of total flavonoid than CHI leaves powder pronouncedly reduced the levels of total cholesterol, triglyceride, and low-density lipoprotein cholesterol in serum in golden hamsters fed a high-fat diet. Furthermore, CHI leaves extract elevated the diversity of gut microbiota and the abundance of Bifidobacterium and Ruminococcaceae_UCG-014. It also decreased the abundance of Lactobacillus at the genus level in golden hamsters fed a high-fat diet. Overall, CHI leaves benefit oxidative stress prevention and metabolic syndrome amelioration in vivo.

From Cocoa to Chocolate: Effect of Processing on Flavanols and Methylxanthines and Their Mechanisms of Action

Despite the health benefits associated with the ingestion of the bioactive compounds in cocoa, the high concentrations of polyphenols and methylxanthines in the raw cocoa beans negatively influence the taste, confer the astringency and bitterness, and affect the stability and digestibility of the cocoa products. It is, therefore, necessary to process cocoa beans to develop the characteristic color, taste, and flavor, and reduce the astringency and bitterness, which are desirable in cocoa products. Processing, however, affects the composition and quantities of the bioactive compounds, resulting in the modification of the health-promoting properties of cocoa beans and chocolate. In this advanced review, we sought to better understand the effect of cocoa's transformational process into chocolate on polyphenols and methylxanthine and the mechanism of action of the original flavanols and methylxanthines. More data on the cocoa processing effect on cocoa bioactives are still needed for better understanding the effect of each processing step on the final polyphenolic and methylxanthine composition of chocolate and other cocoa products. Regarding the mechanisms of action, theobromine acts through the modulation of the fatty acid metabolism, mitochondrial function, and energy metabolism pathways, while flavanols mainly act though the protein kinases and antioxidant pathways. Both flavanols and theobromine seem to be involved in the nitric oxide and neurotrophin regulation.

Chlorogenic acid improves growth performance and intestinal health through autophagy-mediated nuclear factor erythroid 2-related factor 2 pathway in oxidatively stressed broilers induced by dexamethasone

The effects of chlorogenic acid (CGA) on growth performance, intestinal morphology, antioxidant capacity, and the autophagy-mediated nuclear factor erythroid 2-related factor 2 (Nrf2) pathway in oxidatively stressed broilers were investigated. A total of 400 one-day-old male Cobb broilers were divided randomly into 4 groups using a 2 × 2 factorial arrangement with 2 CGA supplemental levels (0 and 500 mg/kg) and 2 dexamethasone (DEX) challenge levels (0 and 3 mg/kg body weight). All the broilers were injected intraperitoneally with DEX or sterile saline beginning at the age of 15 d for 6 consecutive days. The experiment lasted for 21 d. The CGA increased average daily gain (ADG), villus height, villus height/crypt depth (V/C) value, and the protein expressions of Occludin and ZO-1 in the ileum and decreased the feed:gain (F:G) ratio, which were impaired by the DEX challenge. Superoxide dismutase (SOD), catalase (CAT), gutathione S-transferase (GST), and heme oxygenase-1 (HO-1) activities in the serum and ileum were increased by CGA, whereas protein carboxyl (PCO) level in the serum and ileum, and malondialdehyde (MDA) level in the ileum were decreased of the DEX challenged broilers. The DEX challenge decreased microtubule-associated protein 1 light chain 3 (LC3)-II, Beclin1, and autophagy-related gene (ATG) 7 mRNA expressions, and the LC3-II/LC3-I value and increased LC3-I, cysteinyl aspartate specific proteinase (Caspase)-3 and Caspase-9 mRNA expressions in the ileum, which were improved by CGA. DEX also decreased the protein expressions of Kelch-like ECH-associated protein-1 (Keap1), Nrf2, HO-1, NADPH quinone oxidoreductase-1(NQO-1) and increased sequestosome 1 (p62) in the ileum, which were improved by CGA. Interactions occurred between DEX and CGA for the ADG, F:G ratio, villus height, crypt depth, V/C value, and SOD, CAT, GST, and HO-1 activities, MDA and PCO levels, LC3-II/LC3-I value, and expressions of LC3-I, LC3-II, Beclin1, ATG7, Caspase-3, Caspase-9, Occludin, ZO-1, Keap1, Nrf2, HO-1, NQO-1, and p62. In conclusion, CGA improved the growth performance and intestinal health of oxidatively stressed broilers by activating the autophagy-mediated Nrf2 pathway.

The Protective Effect of Polysaccharide SAFP from Sarcodon aspratus on Water Immersion and Restraint Stress-Induced Gastric Ulcer and Modulatory Effects on Gut Microbiota Dysbiosis

Sarcodon aspratus is a popular edible fungus for its tasty flavour and can be used as a dietary supplement for its functional substances. This study was conducted to evaluate the potential health benefits of Sarcodon aspratus polysaccharides (SAFP) on water immersion and restraint stress (WIRS)-induced gastric ulcer in rats. The results indicated that SAFP could decrease myeloperoxidase (MPO) activity and plasma corticosterone levels, as well as enhance Prostaglandin E2 (PGE2) and Nitrate/nitrite (NOx) concentration in rats. Furthermore, SAFP significantly attenuated the stress damage, inflammation, pathological changes and gastric mucosal lesion in rats. Moreover, high-throughput pyrosequencing of 16S rRNA suggested that SAFP modulated the dysbiosis of gut microbiota by enhancing the relative abundance of probiotics, decreasing WIRS-triggered bacteria proliferation. In summary, these results provided the evidence that SAFP exerted a beneficial effect on a WIRS-induced gastric ulcer via blocking the TLR4 signaling pathway and activating the Nrf2 signaling pathway. Notably, SAFP could modulate the WIRS-induced dysbiosis of gut microbiota. Thus, SAFP might be explored as a natural gastric mucosal protective agent in the prevention of gastric ulcers and other related diseases in the food and pharmaceutical industries.

Targeting Nrf2 with Probiotics and Postbiotics in the Treatment of Periodontitis

Periodontitis is a destructive disease of the tooth-surrounding tissues. Infection is the etiological cause of the disease, but its extent and severity depend on the immune–inflammatory response of the host. Immune cells use reactive oxygen species to suppress infections, and there is homeostasis between oxidative and antioxidant mechanisms during periodontal health. During periodontitis, however, increased oxidative stress triggers tissue damage, either directly by activating apoptosis and DNA damage or indirectly by activating proteolytic cascades. Periodontal treatment aims to maintain an infection and inflammation-free zone and, in some cases, regenerate lost tissues. Although mechanical disruption of the oral biofilm is an indispensable part of periodontal treatment, adjunctive measures, such as antibiotics or anti-inflammatory medications, are also frequently used, especially in patients with suppressed immune responses. Recent studies have shown that probiotics activate antioxidant mechanisms and can suppress extensive oxidative stress via their ability to activate nuclear factor erythroid 2-related factor 2 (Nrf2). The aim of this narrative review is to describe the essential role of Nrf2 in the maintenance of periodontal health and to propose possible mechanisms to restore the impaired Nrf2 response in periodontitis, with the aid of probiotic and postbiotics.

Epigallocatechin Gallate Protects against Hypoxia-Induced Inflammation in Microglia via NF-κB Suppression and Nrf-2/HO-1 Activation

Hypoxia-induced neuroinflammation in stroke, neonatal hypoxic encephalopathy, and other diseases subsequently contributes to neurological damage and neuronal diseases. Microglia are the primary neuroimmune cells that play a crucial role in cerebral inflammation. Epigallocatechin gallate (EGCG) has a protective antioxidant and anti-inflammatory effects against neuroinflammation. However, the effects of EGCG on hypoxia-induced inflammation in microglia and the underlying mechanism remain unclear. In this study, we investigated whether EGCG might have a protective effect against hypoxia injury in microglia by treatment with CoCl₂ to establish a hypoxic model of BV2 microglia cells following EGCG pre-treatment. An exposure of cells to CoCl₂ caused an increase in inflammatory mediator interleukin (IL)-6, inducible nitric oxide synthase (iNOS), and cyclooxygenase (COX)-2 expression, which were significantly ameliorated by EGCG via inhibition of NF-κB pathway. In addition, EGCG attenuated the expression of hypoxia-inducible factor (HIF)-1α and the generation of ROS in hypoxic BV2 cells. Furthermore, the suppression of hypoxia-induced IL-6 production by EGCG was mediated via the inhibition of HIF-1α expression and the suppression of ROS generation in BV2 cells. Notably, EGCG increased the Nrf-2 levels and HO-1 levels in the presence of CoCl₂. Additionally, EGCG suppressed hypoxia-induced apoptosis of BV2 microglia with cleavage of poly (ADP-ribose) polymerase (PARP) and caspase-3. In summary, EGCG protects microglia from hypoxia-induced inflammation and oxidative stress via abrogating the NF-κB pathway as well as activating the Nrf-2/HO-1 pathway.

Theaflavin Attenuates TBHP-Induced Endothelial Cells Oxidative Stress by Activating PI3K/AKT/Nrf2 and Accelerates Wound Healing in Rats

The treatment of wounds remains a clinical challenge because of poor angiogenesis under the wound bed, and increasingly, the patients’ need for functional and aesthetically pleasing scars. Previous reports have shown that Theaflavin can induce angiogenesis and terminate the progression of ischemic cardiovascular disease, but limited therapy is available for the management of cutaneous wounds. In this study, our in vitro work discovered that human umbilical vein endothelial cells (HUVECs) exposed to Theaflavin can alleviate apoptosis and cell dysfunction induced by tert-butyl hydroperoxide (TBHP). The cellular activity of HUVECs were assessed by cell tube formation, migration and adhesion. Mechanistically, Theaflavin protected HUVECs from TBHP-stimulated cell apoptosis through the activation of the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT)/nuclear factor (erythroid-derived 2)-like 2 (Nrf2) axis, so Nrf2 silencing can partly eliminate the cytoprotective effect of Theaflavin treatment. In in vivo experiments, administering Theaflavin orally can enhance vascularization in regenerated tissues and accelerate wound healing. In summary, our data served as a novel evidence for the wound healing treatment with Theaflavin, and certified the potential mechanism of Theaflavin, which can be used as a potential agent for cutaneous wound therapy.

NSAID-Associated Small Intestinal Injury: An Overview From Animal Model Development to Pathogenesis, Treatment, and Prevention

With the wide application of non-steroidal anti-inflammatory drugs (NSAIDs), their gastrointestinal side effects are an urgent health burden. There are currently sound preventive measures for upper gastrointestinal injury, however, there is a lack of effective defense against lower gastrointestinal damage. According to a large number of previous animal experiments, a variety of NSAIDs have been demonstrated to induce small intestinal mucosal injury in vivo. This article reviews the descriptive data on the administration dose, administration method, mucosal injury site, and morphological characteristics of inflammatory sites of various NSAIDs. The cells, cytokines, receptors and ligands, pathways, enzyme inhibition, bacteria, enterohepatic circulation, oxidative stress, and other potential pathogenic factors involved in NSAID-associated enteropathy are also reviewed. We point out the limitations of drug modeling at this stage and are also pleased to discover the application prospects of chemically modified NSAIDs, dietary therapy, and many natural products against intestinal mucosal injury.

The effects of cocoa flavanols on indices of muscle recovery and exercise performance: a narrative review

Exercise-induced muscle damage (EIMD) is associated with oxidative stress and inflammation, muscle soreness, and reductions in muscle function. Cocoa flavanols (CF) are (poly)phenols with antioxidant and anti-inflammatory effects and thus may attenuate symptoms of EIMD. The purpose of this narrative review was to collate and evaluate the current literature investigating the effect of CF supplementation on markers of exercise-induced oxidative stress and inflammation, as well as changes in muscle function, perceived soreness, and exercise performance. Acute and sub-chronic intake of CF reduces oxidative stress resulting from exercise. Evidence for the effect of CF on exercise-induced inflammation is lacking and the impact on muscle function, perceived soreness and exercise performance is inconsistent across studies. Supplementation of CF may reduce exercise-induced oxidative stress, with potential for delaying fatigue, but more evidence is required for any definitive conclusions on the impact of CF on markers of EIMD.

Polyphenols from Penthorum chinense Pursh. Attenuates high glucose-induced vascular inflammation through directly interacting with Keap1 protein

ETHNOPHARMACOLOGICAL RELEVANCE

Penthorum chinense Pursh is used for promoting diuresis and alleviating "heat"-associated disorders, which were considered to be related to diabetic in Traditional Chinese Medicine (TCM).

AIMS OF THIS STUDY

Here, we aimed to evaluate the ability and underlying mechanism of the ethyl acetate fraction of Penthorum chinense Pursh stems (PSE) to inhibit vascular inflammation in high glucose (HG)-induced human umbilical vein endothelial cells (HUVEC cells).

MATERIALS AND METHODS

HUVEC cells were pre-treated with PSE following HG treatment. The cell viability, mitochondrial membrane potential (MMP), lactate dehydrogenase (LDH) levels, reactive oxygen species (ROS) generation were analyzed. Inflammatory, and antioxidant,-related proteins were analyzed using western blotting. Molecular docking and drug affinity targeting experiments (DARTS) were utilized to analyze and verify the binding of the Keap1 protein and polyphenols of PSE.

RESULTS

HG can significantly increase the activity of lactic dehydrogenase (LDH), destroy the mitochondrial membrane potential (MMP), and promote the generation of reactive oxygen species (ROS), while PSE treatment reversed these changes. Mechanistically, PSE inhibited NF-κB and inflammatory cytokines activation induced by HG through activating the expression of Nrf2 and its downstream antioxidant proteins Heme oxygenase-1 (HO-1), NAD (P)H Quinone Dehydrogenase 1 (NQO1), Glutamate cysteine ligase catalytic subunit (GCLC), Glutamate-cysteine ligase modifier (GCLM). Further study indicated that PSE activated Nrf2 antioxidant pathway mainly by the binding of primary polyphenols from PSE and the Keap1 protein.

CONCLUSION

Taken together, the present data highlight the health benefits of polyphenols from Penthorum chinense Pursh. regarding diabetes, proving it to be an important source of health care products. Besides, binding of the Keap1 protein may be an effective strategy to activate Nrf2 antioxidant pathway and prevent diabetes.

New insights into the role of the Nrf2 signaling pathway in green tea catechin applications

Nuclear factor-erythroid 2-related factor 2 (Nrf2) is a transcriptional signaling pathway that plays a crucial role in numerous clinical complications. Pivotal roles of Nrf2 have been proved in cancer, autoimmune diseases, neurodegeneration, cardiovascular diseases, diabetes mellitus, renal injuries, respiratory conditions, gastrointestinal disturbances, and general disorders related to oxidative stress, inflammation, apoptosis, gelatinolysis, autophagy, and fibrogenesis processes. Green tea catechins as a rich source of phenolic compounds can deal with various clinical problems and manifestations. In this review, we attempted to focus on intervention between green tea catechins and Nrf2. Green tea catechins especially epigallocatechin gallate (EGCG) elucidated the protective role of Nrf2 and its downstream molecules in various disorders through Keap-1, HO-1, NQO-1, GPx, GCLc, GCLm, NF-kB cross-link, kinases, and apoptotic proteins. Subsequently, we compiled an updated expansions of the Nrf2 role as a gate to manage and protect different disorders and feasible indications of green tea catechins through this signaling pathway. The present review highlighted recent evidence-based data in silico, in vitro, and in vivo studies on an outline for future clinical trials.

Protective Effect of γ-mangostin Isolated from the Peel of Garcinia mangostana against Glutamate-Induced Cytotoxicity in HT22 Hippocampal Neuronal Cells

The aim of the present study was to examine the protective effect of γ-mangostin, a component of the mangosteen shell, against oxidative damage to nerve cells induced by excessive glutamate, a known excitatory neurotransmitter. To investigate the effect of γ-mangostin on apoptosis, 5 mM of glutamate was used to induce apoptotic cell death in mouse hippocampal HT22 cells. In this study, γ-mangostin was found to exert a stronger protection than N-acetyl cysteine against glutamate-induced cell damage. γ-Mangostin showed prevented glutamate-induced apoptosis in HT22 cells by reducing the production of reactive oxygen species and stimulating the expression of heme oxygenase-1 protein. In addition, glutamate significantly induced the accumulation of intracellular calcium ions, whereas treatment with γ-mangostin markedly reduced it. Hoechst 33342 staining showed an improvement in glutamate-induced nuclear condensation following γ-mangostin treatment. Furthermore, the number of annexin V-positive cells was significantly reduced following treatment with γ-mangostin. Western blot analysis showed the inhibition of glutamate-induced mitogen-activated protein kinase phosphorylation by γ-mangostin. γ-mangostin also inhibited the regulation of the intrinsic mitochondrial apoptotic pathway. Thus, the results of this study suggest that γ-mangostin is an active ingredient of mangosteen and exerts neuroprotective activities in HT22 cells.

Gastro-Protective Effects of Albizia anthelmintica Leaf Extract on Indomethacin-Induced Gastric Ulcer in Wistar Rats: In Silico and In Vivo Studies

We have previously reported that the leaf extract of Albizia anthelmintica exhibited substantial antioxidant, anti-inflammatory, analgesic, and antipyretic properties in vivo. We also comprehensively characterized the active phytoconstituents and found several flavonoids and galloyl glucosides derivatives. In the current work, we explored the gastroprotective effects of the leaf extract in an indomethacin-induced ulcer model and the mechanisms involved. The rats being pretreated with the tested extract (100 and 200 mg kg-1) significantly prevented gastric lesions by 87.4% and 92.3%, respectively, and they had no structural derangements in the gastric mucosa. The extract significantly reduced the elevated levels of IKκB, NF-κB, TNF-α, IL-6, iNOS, and lipid peroxidation; increased the reduced level of glutathione peroxidase (GPx) activity; and reduced glutathione (GSH) in the indomethacin-induced ulcer model. The protective activities of the extract were similar in most aspects to those exerted by the known anti-ulcer drug famotidine. These activities might be attributed to the anti-inflammatory and antioxidant activities, and the reduction of iNOS levels. In conclusion, Albizia anthelmintica is a potential candidate for management of gastric ulcers with antioxidant properties.

Mulberroside A repairs high fructose diet-induced damage of intestinal epithelial and blood-brain barriers in mice: A potential for preventing hippocampal neuroinflammatory injury

Our previous studies showed that high fructose diet (HFrD)-driven gut dysbiosis caused fecal short-chain fatty acids (SCFAs) reduction and intestinal epithelial barrier (IEB) damage in mice, which might play an important role in hippocampal neuroinflammatory injury. Mulberroside A is reported to have neuroprotective effects in animal experiments, while the underlying mechanisms are not yet fully elucidated. Here, we investigated whether and how mulberroside A prevented HFrD-induced neuroinflammatory injury. HFrD-fed mice were treated orally with mulberroside A (20 and 40 mg/kg) for 8 weeks. Mulberroside A was found to inhibit hippocampal neuroinflammation and neurogenesis reduction in HFrD-fed mice. It reshaped gut dysbiosis, increased fecal and serum SCFAs contents, reactivated signaling of the colonic NLR family, pyrin domain containing 6 (NLRP6) inflammasome, and up-regulated Muc2 expression to prevent IEB damage, as well as subsequently, reduced serum endotoxin levels in this animal model. Additionally, mulberroside A inhibited oxidative stress in colon of HFrD-fed mice and hydrogen peroxide (H₂ O₂ )-stimulated Caco-2 cells. Blood-brain barrier (BBB) structure defects were also observed in HFrD-driven hippocampal neuroinflammatory injury of mice. Interestingly, mulberroside A maintained astrocyte morphology and up-regulated tight junction proteins to repair BBB structure defects in hippocampus dentate gyrus (DG). Our results demonstrated that mulberroside A was capable of preventing HFrD-induced damage of IEB and BBB in mice, which might contribute to the suppression of hippocampal neuroinflammatory injury.

A Review of the Role of Flavonoids in Peptic Ulcer (2010-2020)

Peptic ulcers are characterized by erosions on the mucosa of the gastrointestinal tract that may reach the muscle layer. Their etiology is multifactorial and occurs when the balance between offensive and protective factors of the mucosa is disturbed. Peptic ulcers represent a global health problem, affecting millions of people worldwide and showing high rates of recurrence. Helicobacter pylori infection and the use of non-steroidal anti-inflammatory drugs (NSAIDs) are one of the most important predisposing factors for the development of peptic ulcers. Therefore, new approaches to complementary treatments are needed to prevent the development of ulcers and their recurrence. Natural products such as medicinal plants and their isolated compounds have been widely used in experimental models of peptic ulcers. Flavonoids are among the molecules of greatest interest in biological assays due to their anti-inflammatory and antioxidant properties. The present study is a literature review of flavonoids that have been reported to show peptic ulcer activity in experimental models. Studies published from January 2010 to January 2020 were selected from reference databases. This review refers to a collection of flavonoids with antiulcer activity in vivo and in vitro models.

Preventative and Therapeutic Potential of Flavonoids in Peptic Ulcers

Peptic ulcer disease is a common gastrointestinal tract disorder that affects up to 20% of the population of the world. Treatment of peptic ulcer remains challenging due to the limited effectiveness and severe side effects of the currently available drugs. Hence, natural compounds, owing to their medicinal, ecological, and other safe properties, are becoming popular potential candidates in preventing and treating peptic ulcers. Flavonoids, the most abundant polyphenols in plants, exhibit gastroprotective effects against peptic ulcer both in vivo and in vitro. In this review, we summarized the anti-ulcer functions and mechanisms, and also the bioavailability, efficacy, and safety, of flavonoid monomers in the gastrointestinal tract. Flavonoids exerted cytoprotective and rehabilitative effects by not only strengthening defense factors, such as mucus and prostaglandins, but also protecting against potentially harmful factors via their antioxidative, anti-inflammatory, and antibacterial activities. Although controlled clinical studies are limited at present, flavonoids have shown a promising preventable and therapeutic potential in peptic ulcers.

Immunomodulation effects of polyphenols from thinned peach treated by different drying methods on RAW264.7 cells through the NF-κB and Nrf2 pathways

Thinned peach is abundant in polyphenols, and has been shown to exhibit various bioactivities. In this study, we evaluated the underlying immunomodulatory activity of polyphenol extracts of thinned peach (PETP) via the NF-κB and Nrf2 signaling pathways in RAW264.7 macrophages. The results demonstrated that the PETP efficiently activated the nuclear translocation of NF-κB and Nrf2, as well as downstream cytokines (IL-1β, IL-6, TNF-α and IFN-γ), SOD activity and ROS levels in RAW264.7 cells. Specifically, the PETP of natural drying and hot air drying exhibited less efficacy than that of freeze drying in NF-κB pathway. Interestingly, the PETP of hot air drying at 50 °C was more effective than freeze-dried PETP in activating Nrf2 nuclear translocation. Additionally, 50 µg/mL PETP enhanced immune responses, whereas 800 µg/mL PETP inhibited inflammatory development in macrophages. These findings indicated that different PETP affected the immunomodulation effects differently, which associated with the drying methods and incubation concentrations.

Brazilian berry extract (Myrciaria jaboticaba): A promising therapy to minimize prostatic inflammation and oxidative stress

BACKGROUND

Brazilian berry is a fruit popularly known as "Jaboticaba," rich in bioactive compounds with antioxidant and anti-inflammatory properties. Senescence and overweight are increasing worldwide and are considered risk factors to prostatic pathogenesis mainly due to oxidative and inflammatory processes induction. Thus, this study aimed to evaluate the effect of two increasing doses of the patented jaboticaba peel extract (PJE) on oxidative-stress and inflammation in the prostate of aging or high-fat-fed aging mice.

METHODS

PJE and/or high-fat diet (HFD) treatments started with 11-month-old mice and lasted 60 days. The levels or the immunoexpression of different inflammatory (nuclear factor κB [NFκB], CD3+, cyclooxygenase 2 [COX-2], toll-like receptor 4 [TLR4], phosphorylated signal transducers and activators of transcription 3 [pSTAT-3], tumor necrosis factor α [TNF-α], interleukin 6 [IL-6], and IL-1β) and oxidative-stress (catalase, superoxide dismutase 2 [SOD2], glutathione reductase [GSR], reduced glutathione, and glutathione peroxidase 3 [GPx3]) related molecules were analyzed by western-blotting, immunohistochemistry, and enzyme-linked immunosorbent assays.

RESULTS

Both PJE doses reduced the levels of oxidative-stress-related molecules (GPx3, GSR, catalase), lipid peroxidation (4-hydroxynonenal), inflammatory mediators (COX-2, TNF-α, and pSTAT-3) and CD3+ T cells number, which were associated with the maintenance of the glandular morphological integrity in aging and HFD-fed-aging mice. Nevertheless, only the high PJE dose reduced the NFκB and TLR4 levels in aging mice; and SOD2, IL-6, and IL-1β levels in HFD-aging mice. Aging itself promoted an oxidative inflammation in the prostate, interfering in the levels of the different oxidative-stress, lipid peroxidation, and inflammatory mediators evaluated, in association with high incidence of prostate epithelial and stromal damages. The HFD intake intensified aging alterations, showing an unfavorable prostatic microenvironment prone to oxidative and inflammatory damages.

CONCLUSIONS

PJE exerted a dose-dependent effect controlling inflammation and oxidative-stress in aging and HFD-fed aging mice prostate. This fact contributed to prostate microenvironment balance recovery, preserving the tissue architecture of this gland. Thus, the PJE emerges as a potential therapy to prevent inflammation and oxidative stress in the prostate.

Genome-Protecting Compounds as Potential Geroprotectors

Throughout life, organisms are exposed to various exogenous and endogenous factors that cause DNA damages and somatic mutations provoking genomic instability. At a young age, compensatory mechanisms of genome protection are activated to prevent phenotypic and functional changes. However, the increasing stress and age-related deterioration in the functioning of these mechanisms result in damage accumulation, overcoming the functional threshold. This leads to aging and the development of age-related diseases. There are several ways to counteract these changes: 1) prevention of DNA damage through stimulation of antioxidant and detoxification systems, as well as transition metal chelation; 2) regulation of DNA methylation, chromatin structure, non-coding RNA activity and prevention of nuclear architecture alterations; 3) improving DNA damage response and repair; 4) selective removal of damaged non-functional and senescent cells. In the article, we have reviewed data about the effects of various trace elements, vitamins, polyphenols, terpenes, and other phytochemicals, as well as a number of synthetic pharmacological substances in these ways. Most of the compounds demonstrate the geroprotective potential and increase the lifespan in model organisms. However, their genome-protecting effects are non-selective and often are conditioned by hormesis. Consequently, the development of selective drugs targeting genome protection is an advanced direction.

MicroRNA-based regulatory mechanisms underlying the synergistic antioxidant action of quercetin and catechin in H2O2-stimulated HepG2 cells: Roles of BACH1 in Nrf2-dependent pathways

The microRNA-based mechanisms underlying the antioxidant action(s) of co-existing flavonoids in response to oxidative stress are of high interest. This study aimed to extend the existing knowledge and provide insights into the potential regulatory network in response to oxidative stress and the co-presence of quercetin and catechin antioxidants, via a preclinical approach using H₂O₂-stimulated HepG2 cells. It was confirmed that BACH1 serves as an essential and direct negative regulator of the Keap1-Nrf2 signaling pathway and the antioxidant synergism between quercetin and catechin. BACH1 promoted reactive oxygen species (ROS) accumulation while inhibiting cell growth, which could be reversed by the synergistic action of let-7a-5p and miR-25-3p in the co-presence of quercetin and catechin. Both let-7a-5p and miR-25-3p could directly regulate the expression and function of BACH1 (e.g. upregulation of the two miRNAs could rescue largely overexpression of BACH1). Although these molecular interactions likely represented only some aspects of the overall regulatory network, this research confirms the feasibility of the combined uses of dietary flavonoids with chemopreventive properties in synergy during multiple-target interactions and multiple-pathway regulation.

Oxidative stress responsive transcription factors in cellular signalling transduction mechanisms

Oxidative stress results from the imbalances in the development of reactive oxygen species (ROS) and antioxidants defence system resulting in tissue injury. A key issue resulting in the modulation of ROS is that it alters hosts molecular, structural and functional properties which is accomplished via various signalling pathways which either activate or inhibit numerous transcription factors (TFs). Some of the regulators include Nuclear erythroid-2 related factors (Nrf-2), CCAAT/enhancer-binding protein delta (CEBPD), Activator Protein-1 (AP-1), Hypoxia-inducible factor 1(HIF-1), Nuclear factor κB (NF-κB), Specificity Protein-1 (SP-1) and Forkhead Box class O (FoxO) transcription factors. The expression of these transcription factors are dependent upon the stress signal and are sometimes interlinked. They are highly specific having their own regulation cellular events. Depending upon the transcription factors and better knowledge on the type of the oxidative stress help researchers develop safe, novel targets which can serve as efficient therapeutic targets for several disease conditions.

The Effects of Dietary Supplements that Overactivate the Nrf2/ARE System

Background:

Inflammation is one of the most misunderstood aspects of human health. People have been encouraged to eat foods that have a high antioxidant capacity, and in vitro tests for total antioxidant capacity emerged. They were based on measuring the destruction of oxidized test compounds in direct reactions with the antioxidants in foods. Many dietary supplements arrived in the market. They contained purified antioxidants, such as resveratrol and EGCG that were and still are widely assumed by many to be quite healthy at any dose.

Methods:

The literature on inflammation and the Nrf2/ARE antioxidant system was searched systematically. Articles from prestigious, peer-reviewed journals were obtained and read. The information obtained from them was used to write this review article.

Results:

Over 150 articles and books were read. The information obtained from them showed that very few dietary antioxidants exert their effects by reacting directly with Reactive Oxygen and Nitrogen Species (RONS). Instead, most of the effective antioxidants activate the endogenous Nrf2/ARE antioxidant system. This helps prevent smoldering inflammation and the diseases that it can cause. However, when overactivated or activated constitutively, the Nrf2/ARE antioxidant system can cause some of these diseases, including many types of multidrug resistant cancer, autoimmune, neurodegenerative and cardiovascular diseases.

Conclusion:

Even though green tea, as well as many fruits, vegetables and spices are quite healthy, dietary supplements that deliver much higher doses of antioxidants may not be. People who are diagnosed with cancer and plan to start chemotherapy and/or radiotherapy should probably avoid such supplements. This is because multidrug resistant tumors can hijack and overactivate the Nrf2/ARE antioxidant system.

Effects of phytogenic feed additives on cellular oxidative stress and inflammatory reactions in intestinal porcine epithelial cells1

Due to increasing concerns about the use of antibiotic growth promoters (AGP) in livestock production and their complete ban in the European Union in 2006, suitable alternatives are urgently needed. Among others, anti-inflammatory activities of AGP are discussed as their putative mode of action. As numerous phytochemicals are known to modulate the cellular antioxidant capacity and immune response, we studied the antioxidative and anti-inflammatory properties of a phytogenic (plant-derived) feed additive (PFA) in intestinal porcine epithelial cells (IPEC-J2). The effects of the PFA were compared with those of selected phytogenic ingredients (grape seed extract [GRS], licorice extract [LIC], menthol [MENT], methyl salicylate [MES], oak bark extract [OAK], oregano essential oil [ORE], and a plant powder mix [PLA]), and with the effects of the AGP tylosin (TYL). Oxidative or inflammatory stress was induced by stimulating IPEC-J2 with hydrogen peroxide (H2O2; 0.5 mM) or tumor necrosis factor alpha (TNF-α; 10 ng/mL), respectively. The antioxidative effects of feed additives were assessed with a reactive oxygen species (ROS)-sensitive probe and by measuring the expression of 6 antioxidative target genes via quantitative real-time PCR (RT-qPCR). Anti-inflammatory potential was analyzed using a nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) reporter gene assay. Moreover, the expression levels of 6 NF-κB target genes were measured using RT-qPCR analysis, and the release of IL-6 was analyzed via ELISA. Significant decreases in cellular ROS upon H2O2 treatment were observed for the PFA (P < 0.001), LIC (P < 0.001), ORE (P < 0.05), and GRS (P < 0.01). No significant changes in the expression of antioxidative genes were found. NF-κB activation upon TNF-α treatment was significantly inhibited by the PFA (P < 0.05) and by ORE (P < 0.001). Moreover, the PFA and ORE significantly reduced the gene expression of IL-6 (P < 0.001), IL-8 (P < 0.001), and C-C motif chemokine ligand 2 (CCL2; P < 0.05), as well as the release of IL-6 (P < 0.05). The other phytogenic compounds as well as the AGP TYL did not significantly affect any of the inflammatory parameters. In summary, we revealed the antioxidative properties of the PFA, LIC, ORE, and GRS, as well as anti-inflammatory properties of the PFA and ORE in IPEC-J2, providing a better understanding of the mode of action of this PFA under our experimental conditions.

Induction of EpRE-mediated gene expression by a series of mediterranean botanicals and their constituents

ETHNOPHARMACOLOGICAL RELEVANCE

A variety of Mediterranean plant species, traditionally used for the prevention and treatment of several health conditions, contain ingredients with potential biological activity of which many remain unexplored. Among the beneficial health effects of bioactive phytochemicals is the activation of cellular defense mechanisms involving the activation of EpRE (electrophile responsive element) - mediated changes in gene expression.

AIM OF THE STUDY

The present study aimed to identify botanicals and their active constituents able to activate the EpRE mediated gene expression within a series of Mediterranean plant species known for their hepatoprotective and/or cardioprotective properties.

MATERIALS AND METHODS

Methanolic extracts of 18 botanicals were prepared and tested for their ability to induce gene expression in EpRE-LUX reporter cells. Subsequently, LC-MS (Liquid Chromatography Mass Spectrometry) analysis combined with MAGMa (MS Annotation based on in silico Generated Metabolites) software for automated compound annotation was used to facilitate tentative identification of the active constituents within two of the active extracts. Selected annotated compounds were tested in the EpRE-LUX reporter gene assay followed by definite identification of the most active ones.

RESULTS

It appeared that 9 of the 18 extracts were able to activate EpRE-mediated gene expression. Many active ingredients of the methanolic extracts from Juglans regia and Rhamnus frangula were revealed. Among them, chrysophanol and aloe-emodin were confirmed to be active EpRE inducing ingredients and were definitely identified in the Rhamnus Frangula extract.

CONCLUSIONS

The protective effect of half of the tested botanical varieties via the activation of EpRE-mediated gene expression was confirmed. The study also provided an example of how in vitro bioassays can be combined with LC-MS and the automated chemical annotation software MAGMa, to identify biologically active constituents in complex botanical extracts.

Protocatechuic acid-mediated DJ-1/PARK7 activation followed by PI3K/mTOR signaling pathway activation as a novel mechanism for protection against ketoprofen-induced oxidative damage in the gastrointestinal mucosa

Oxidative stress contributes to the progression of non-steroidal anti-inflammatory drug (NSAID)-induced gastrointestinal (GI) cell apoptosis. In our previous study, we reported that nuclear factor erythroid 2-related factor 2 (Nrf2) plays a protective role against ketoprofen-induced GI mucosal oxidative injury. Recent reports suggest that Nrf2 could exhibit antioxidative and antiapoptosis responses through up-regulation of DJ-1 (PARK7). In the current study, we proposed that induction of DJ-1 expression by protocatechuic acid (PCA) might provide a potential therapeutic approach for treating oxidative stress-associated GI ulcer diseases. The results indicated that PCA increased mRNA expression of glutathione peroxidase and heme oxygenase-1 through up-regulation of DJ-1 followed by Nrf2 translocation. Furthermore, PCA protected Int-407 cells against ketoprofen-induced oxidative stress by regulating the DJ-1, PI3K, and mTOR pathways. Pretreatment with PCA inhibited mitochondrial ROS generation, up-regulated the mitochondrial membrane potential, and down-regulated pro-apoptotic Bax as well as downstream caspase-8, caspase-9, and caspase-3 activity, and reversed impaired DJ-1 and anti-apoptotic Bcl-2 protein expression in Int-407 cells induced by ketoprofen. Similar to the in vitro results, SD rats treated with PCA before administration of ketoprofen exhibited decreased caspase-3 protein expression as well as oxidative damage, and impairment of the antioxidant system and DJ-1 protein expression in the GI mucosa were reversed. The administration of lansoprazole, a type of proton pump inhibitor (PPI), strongly inhibited ketoprofen-induced GI mucosal injuries via up-regulation of DJ-1, indicating that DJ-1 is essential for the dietary antioxidant- and PPI drug-mediated mechanism of ulcer therapy. These results suggest that DJ-1 could be a novel target for protection against ketoprofen-induced GI ulcers due to its antioxidant and anti-apoptosis characteristics.

Crosstalk of toll-like receptors signaling and Nrf2 pathway for regulation of inflammation

Inflammation as a second line of defense of innate immunity plays a crucial role in eliminating invading pathogens (bacteria, viruses, fungi as well as other parasites). The inflammatory response may also activate adaptive immune system involving lymphocytes to mount either antibody dependent or cell-mediated immune responses to clear pathogenic insult. However, if continued, the inflammatory processes may become uncontrolled culminating in cellular injury and tissue destruction, thereby manifesting itself in chronic form. The chronic inflammation has been associated with numerous human pathological conditions like allergies and autoimmune diseases, atherosclerosis, arthritis, Alzheimer's disease, cancer, obesity, type 2 diabetes, schizophrenia, neuro-degenerative diseases and numerous others. The dysregulated inflammatory process is associated with overproduction of free radicals leading to oxidative stress and activation of different cell signaling pathways. The regulation of inflammation by TLR signaling as well as Nrf2 pathways separately is widely documented. Since both these major signaling pathways modulate inflammation, they may crosstalk to bring about coordinated inflammatory responses. The linkage between TLR signaling and Nrf2-Keap1 pathway may serve as a bridge between immune regulation and oxidative stress responses through regulation of inflammation. Also, inflammation is reportedly responsible for the plethora of diseased conditions; a study of its regulation by targeting the TLR-Nrf2 cross-talks may also be beneficial for the development of therapeutic therapies or prophylactic treatments. Hence, present review focuses on the crosstalk between TLR signaling and Nrf2 pathway with respect to their role in modulation of inflammation in normal as well as pathologic conditions.

Polyphenols (S3) Isolated from Cone Scales of Pinus koraiensis Alleviate Decreased Bone Formation in Rat under Simulated Microgravity

In order to screen out an effective bone loss protectant from natural plant polyphenol and to elucidate the mechanism of the plant polyphenols that alleviate bone loss under simulated microgravity, the proliferation activities of 9 total polyphenol extracts from natural product (TPENP) on osteoblasts were measured. Polyphenols (S3) was isolated from total polyphenols of cone scales from pinus koraiensis (Korean pine). ALP activity in osteoblasts and MDA level in femur were measured. Mechanical properties and microstructure of the distal cancellous region of the femur in rat were tested. Various bone metabolism markers, enzymes activity and genes expression were also analyzed. The results showed that S3 has the highest activity of osteoblast proliferation. S3 promoted ALP activity in osteoblasts, enhanced mechanical properties and microstructure of the distal cancellous region of femur in rat, decreased MDA level, elevated the serum concentration of BALP, PINP and activities of SOD, CAT, GSH-Px in femur under simulated microgravity. In addition, S3 enhanced the expression of NRF-2, β-catenin, p-GSK3-β, OSX, RUNX2, Osteonectin, Osteocalcin, ALP and collagen I. These results indicated that S3 can alleviated bone loss induced by simulated microgravity through abate the inhibition of the oxidative stress on Wnt/β-catenin signaling pathway.

Chlorogenic acid improves intestinal barrier functions by suppressing mucosa inflammation and improving antioxidant capacity in weaned pigs

Intestinal barrier plays key roles in maintaining intestinal homeostasis. Inflammation and oxidative damage can severely destroy the intestinal integrity of mammals. Chlorogenic acid (CGA) is a natural polyphenol present in human diet and plants, possessing potent antioxidant and anti-inflammatory activities. This study was conducted to investigate the protective effects of CGA and its molecular mechanisms on intestinal barrier function in a porcine model. Twenty-four weaned pigs were allotted to two groups and fed with a basal diet or a basal diet containing 1000 mg/kg CGA. The results showed that CGA decreased serum D-lactate and diamine oxidase levels, and enhanced the expression and localization of claudin-1 protein in apical intercellular region of small intestinal epithelium. Interestingly, CGA significantly decreased the mucosa histamine and tryptase contents, as well as the tryptase-positive mast cell counts. Moreover, the expression levels of critical inflammation molecules (interleukin-1β, interleukin-6, tumor necrosis factor-α, and nuclear factor-κB) were down-regulated by CGA in jejunal and ileal mucosa. However, the expression levels of inflammation repressors (suppressor of cytokine signaling 1 and toll-interacting protein) were up-regulated by CGA. Importantly, CGA decreased the malondialdehyde content but elevated glutathione peroxidase and catalase content in duodenal and jejunal mucosa. The expression levels of critical molecules in antioxidant signaling (nuclear factor erythroid-derived 2-related factor 2 and heme oxygenase-1) were elevated by CGA in duodenal and jejunal mucosa. These results suggested that CGA could ameliorate intestinal barrier disruption in weaned pigs, which might be mediated by suppressing the TLR4/NF-κB signaling pathway and activating the Nrf2/HO-1 signaling pathway.

PLGA Microspheres Loaded with β-Cyclodextrin Complexes of Epigallocatechin-3-Gallate for the Anti-Inflammatory Properties in Activated Microglial Cells

Although epigallocatechin-3-gallate (EG) is well-known as a potent antioxidant and free radical scavenger for neurodegenerative diseases, it still has disadvantages that reduce its treatment effectiveness due to low bioavailability, slow absorption, and water solubility. Therefore, the aim of this study is to improve the bioavailability of EG and increase the effectiveness of anti-inflammatory properties to microglial cells by using Poly(Lactide-co-Glycolide) (PLGA) microspheres as carriers. In this study, we used UV–Vis spectroscopy to show the formation of the complex of β-cyclodextrin (β-CD) and EG (CD-EG). The loading efficiency of EG in PLGA microspheres was optimized by the addition of β-CD. The highest loading efficiency of 16.34% was found among other formulations. The results of Fourier transform infrared spectroscopy indicated the loading of CD-EG in PLGA microspheres. The scanning electron microscopic images demonstrated the spherical PLGA particles with controlled particles size ranging from 1–14 µm. Moreover, the in vitro release of EG was conducted to explore the sustained release property of the PLGA formulations. In the in vitro model of mouse microglial cells (BV-2 cells) stimulated by lipopolysaccharide, the cytotoxicity test showed that for up to 1 mg/mL of PLGA microspheres no toxicity to BV-2 cells was found. PLGA microspheres can significantly suppress the nitric oxide production from BV-2 cells, indicating EG loaded in PLGA microspheres can suppress the inflammation of activated microglial cells. Furthermore, the intracellular iNOS in BV-2 cells was also found to be down regulated. In summary, we have successfully shown that the use of β-CD can increase the loading efficiency of EG in PLGA microspheres and provide neuroprotective effect on the activated microglial cells.

Role of NRF2 in protection of the gastrointestinal tract against oxidative stress

The gastrointestinal tract is exposed to a variety of noxious factors, such as Helicobacter pylori, nonsteroidal anti-inflammatory drugs, gastric acid, ischemia-reperfusion, and mental stresses. Theses stressors generate free radicals within gastrointestinal tissues, causing organ injury and functional disturbance. Although the gastrointestinal tract can withstand such oxidative stresses to some extent by enhancing its antioxidant system via nuclear factor erythroid 2-related factor 2-Kelch-like erythroid cell-derived protein with CNC homology-associated protein 1-mediated pathways, acute or chronic exposure to oxidative stress can cause several gastrointestinal tract disorders, such as inflammation, ulcers, cancers, and various functional disturbances. Recent studies have demonstrated that some natural compounds and drugs can upregulate the nuclear factor erythroid 2-related factor 2-mediated antioxidant system, ameliorating or preventing these disorders. Although these compounds may be useful as chemopreventive agents, sufficient evidence for their clinical efficacy has not yet been provided. In addition, it is important to note that excessive nuclear factor erythroid 2-related factor 2 stimulation can be harmful to human health, especially from the standpoint of tumor biology.

Biotransformation and oxidative stress responses in rat hepatic cell-line (H4IIE) exposed to racemic ketoprofen (RS-KP) and its enantiomer, dexketoprofen (S(+)-KP)

Pharmaceuticals such as racemate ketoprofen (RS-KP) and its enantiomer, dexketoprofen (S(+)-KP) are highly detectable non-steroidal anti-inflammatory drugs (NSAIDs) in the aquatic environment and therefore are designated as one of the most emerging groups of pollutants that can affect environmental and human health. The potential impact of these pharmaceuticals was assessed for the first time in vitro using a rat hepatocellular carcinoma cell line (H4IIE). Cells were exposed to low and high concentrations of these drugs. Cytotoxicity was determined by MTT reduction assay; CYP1A1 transcriptional and enzymatic levels together with canonical oxidative stress responsive markers (GPx, GR, GST and CAT) were also investigated. Cells exposed to RS-KP and S(+)-KP did not show cytotoxicity effect at the concentrations tested. However, this study highlighted differences between RS-KP and S(+)-KP in most of the evaluated markers, showing compound-, concentration- and time-specific effect patterns which suggest a potential stereo-selective toxicity of these drugs.

Complementary effects of cereal and pulse polyphenols and dietary fiber on chronic inflammation and gut health

Cereal grains and grain pulses are primary staples often consumed together, and contribute a major portion of daily human calorie and protein intake globally. Protective effects of consuming whole grain cereals and grain pulses against various inflammation-related chronic diseases are well documented. However, potential benefits of combined intake of whole cereals and pulses beyond their complementary amino acid nutrition is rarely considered in literature. There is ample evidence that key bioactive components of whole grain cereals and pulses are structurally different and thus may be optimized to provide synergistic/complementary health benefits. Among the most important whole grain bioactive components are polyphenols and dietary fiber, not only because of their demonstrated biological function, but also their major impact on consumer choice of whole grain/pulse products. This review highlights the distinct structural differences between key cereal grain and pulse polyphenols and non-starch polysaccharides (dietary fiber), and the evidence on specific synergistic/complementary benefits of combining the bioactive components from the two commodities. Interactive effects of the polyphenols and fiber on gut microbiota and associated benefits to colon health, and against systemic inflammation, are discussed. Processing technologies that can be used to further enhance the interactive benefits of combined cereal-pulse bioactive compounds are highlighted.

Improvement of gastroprotective and anti-ulcer effect of kenaf seed oil-in-water nanoemulsions in rats

Kenaf seed oil-in-water nanoemulsions (KSON) and kenaf seed oil-in-water macroemulsions were produced to access their gastroprotective effect against indomethacin- and ethanol-induced ulcers in comparison with non-emulsified kenaf seed oil (KSO). Emulsifier mixture (EM) that used to emulsify KSO was also included in the study. Ulcer index, stomach tissue oxidative status, and histopathological changes in indomethacin-induced and ethanol-induced ulcer models were both evaluated. KSON had demonstrated good gastroprotective effect against both ulcer models than non-emulsified KSO and KSOM. In addition, the gastroprotective effect of KSON was comparable to the standard drug, Omeprazole. EM also exhibited gastroprotective effect, especially in indomethacin-induced ulcers. This may be attributed to its high antioxidant activity and cytoprotective effect of sodium caseinate contained in the EM. Results supported that KSON enhanced the bioavailability of native KSO; therefore it offers gastroprotective effect for the prevention of gastric ulceration as a natural alternative to the synthetic drug.

Protective effect of coptisine free base on indomethacin-induced gastric ulcers in rats: Characterization of potential molecular mechanisms

AIMS

The aim of this study was to comparatively investigate the potential gastroprotective effect and underlying mechanisms of coptisine free base (CFB, 8-hydroxy-7, 8-dihydrocoptisine), berberine and lansoprazole against indomethacin-induced gastric ulcer in rats.

MATERIALS AND METHODS

CFB (10, 20 and 40mg/kg), berberine (20mg/kg) and lansoprazole (30mg/kg) were orally administrated to rats prior to indometacin ingestion, and gastric lesions were evaluated macroscopically and histologically, and further analyzed by ELISA, qRT-PCR and Western blot.

KEY FINDINGS

CFB exerted comparable or superior gastroprotective effect to berberine in protecting against indomethacin-induced gastric injury. CFB pretreatment significantly enhanced the levels of superoxide dismutase (SOD) and glutathione (GSH), and markedly decreased the malonaldehyde (MDA) content. CFB administration effectively suppressed the levels of myeloperoxidase (MPO), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and angiotensin II (Ang II). Besides, CFB substantially up-regulated the mRNA expressions of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2), and promoted gastric mucosal prostaglandin E₂ level (PGE₂). Furthermore, CFB pretreatment remarkably increased the translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) from cytosol into the nucleus, and the expression of heme oxygenase-1 (HO-1), while significantly decreased the expression of mitogen activated protein Kinase Kinase 6 (MKK6) and translocation of p38 mitogen-activated protein kinase (p38 MAPK).

SIGNIFICANCE

This was the first investigation reporting the anti-ulcer effect of protoberberine alkaloid free base on in vivo rodent model. The gastroprotective mechanism of CFB might involve favorable regulation of antioxidant and anti-inflammatory status mediated, at least partially, by the Nrf2 signaling pathway and p38 MAPK translocation.