Dietary unsaponifiable fraction from extra virgin olive oil supplementation attenuates acute ulcerative colitis in mice

More Than Pigments: The Potential of Astaxanthin and Bacterioruberin-Based Nanomedicines

Carotenoids are natural products regulated by the food sector, currently used as feed dyes and as antioxidants in dietary supplements and composing functional foods for human consumption. Of the nearly one thousand carotenoids described to date, only retinoids, derived from beta carotene, have the status of a drug and are regulated by the pharmaceutical sector. In this review, we address a novel field: the transformation of xanthophylls, particularly the highly marketed astaxanthin and the practically unknown bacterioruberin, in therapeutic agents by altering their pharmacokinetics, biodistribution, and pharmacodynamics through their formulation as nanomedicines. The antioxidant activity of xanthophylls is mediated by routes different from those of the classical oral anti-inflammatory drugs such as corticosteroids and non-steroidal anti-inflammatory drugs (NSAIDs): remarkably, xanthophylls lack therapeutic activity but also lack toxicity. Formulated as nanomedicines, xanthophylls gain therapeutic activity by mechanisms other than increased bioavailability. Loaded into ad hoc tailored nanoparticles to protect their structure throughout storage and during gastrointestinal transit or skin penetration, xanthophylls can be targeted and delivered to selected inflamed cell groups, achieving a massive intracellular concentration after endocytosis of small doses of formulation. Most first reports showing the activities of oral and topical anti-inflammatory xanthophyll-based nanomedicines against chronic diseases such as inflammatory bowel disease, psoriasis, atopic dermatitis, and dry eye disease emerged between 2020 and 2023. Here we discuss in detail their preclinical performance, mostly targeted vesicular and polymeric nanoparticles, on cellular models and in vivo. The results, although preliminary, are auspicious enough to speculate upon their potential use for oral or topical administration in the treatment of chronic inflammatory diseases.

The Potential of Natural Oils to Improve Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic intestinal inflammatory disorder that includes ulcerative colitis (UC) and Crohn's disease (CD), the exact cause of which is still unknown. Numerous studies have confirmed that diet is one of the major environmental factors associated with IBD, as it can regulate the gut microbiota and reduce inflammation and oxidative stress. Since the consumption of oil is essential in the diet, improving IBD through oil has potential. In this article, we first briefly reviewed the current treatment methods for IBD and introduce the role of natural oils in improving inflammatory diseases. We then focused on the recent discovery of the role of natural oils in the prevention and treatment of IBD and summarized their main mechanisms of action. The results showed that the anti-inflammatory activity of oils derived from different plants and animals has been validated in various experimental animal models. These oils are capable of improving the intestinal homeostasis in IBD animal models through multiple mechanisms, including modulation of the gut microbiota, protection of the intestinal barrier, reduction in colonic inflammation, improvement in oxidative stress levels in the intestine, and regulation of immune homeostasis. Therefore, dietary or topical use of natural oils may have potential therapeutic effects on IBD. However, currently, only a few clinical trials support the aforementioned conclusions. This review emphasized the positive effects of natural oils on IBD and encouraged more clinical trials to provide more reliable evidence on the improvement of human IBD by natural oils as functional substances.

Effects of Olive Oil and Its Components on Intestinal Inflammation and Inflammatory Bowel Disease

With the rising global burden of inflammatory bowel disease (IBD) and the rising costs of novel biological drugs, there is an increasing need for dietary approaches and functional foods that could modulate the course of IBD. The Mediterranean diet has proven to be efficacious in managing chronic inflammatory diseases, and recent studies have also shown its benefits in the setting of IBD. Since olive oil and its compounds have been shown to provide a considerable anti-inflammatory effect, in this review, we aim to discuss the latest evidence concerning the impact of olive oil and its bioactive compounds on IBD. Numerous preclinical studies have exhibited solid evidence on the mechanisms by which polyphenol-rich extra-virgin olive oil (EVOO) or specific polyphenols like hydroxytyrosol (HT) provide their anti-inflammatory, antioxidative, antitumour, and microbiota-modulation effects. Accordingly, several human studies that explored the effects of olive oil on patients with IBD further confirmed the evidence brought forward by preclinical studies. Nevertheless, there is a need for larger-scale, multicentric, randomized control trials that would finally elucidate olive oil’s level of efficacy in modulating the course of IBD.

Effects of olives and their constituents on the expression of ulcerative colitis: a systematic review of randomised controlled trials

Extra virgin olive oil is often associated with anti-inflammatory and antioxidant properties. Its effects on inflammatory conditions such as ulcerative colitis (UC), however, have yet to be defined. As such, we aimed to conduct a systematic review and meta-analysis of studies investigating olive-based interventions in UC. A comprehensive database search for randomised controlled trials was performed between 9 July 2018 and 16 August 2018. Studies identified from search alerts were included up to 22 June 2020. Both individuals living with UC at any disease stage and murine models of UC were included in this review. No human trials meeting the eligibility criteria were identified, while nineteen animal studies comprised 849 murine models of UC were included in this review. Pooling of the data could not be performed due to heterogeneous outcomes; however, general trends favouring olive-based interventions were identified. Milder disease expression including weight maintenance, reduced rectal bleeding and well-formed stools favouring olive-based interventions was statistically significant in 16/19 studies, with moderate-to-large effect sizes (-0·66 (95 % CI -1·56, 0·24) to -12·70 (95 % CI -16·8, -8·7)). Olive-based interventions did not prevent the development of colitis-like pathologies in any study. In conclusion, effects of olive-based interventions on murine models of UC appear promising, with milder disease outcomes favouring the intervention in most trials and effect sizes suggesting potential clinical relevance. However, the lack of published randomised controlled human trials warrants further investigation to determine if these effects would translate to individuals living with UC.

Sour Cherry (Cerasus vulgaris Miller) Kernel Oil as the Novel Functional Edible Oil: Sensory Evaluation and Antioxidant and Physicochemical Properties

This study aims to extract oil from fresh sour cherry kernel (Cerasus vulgaris Miller) using the cold press method. The oil content and moisture were obtained as 31.89% and 4%, respectively. The organoleptic assessment of the oil was acceptable and the free fatty acid value was obtained as 1.36 (mg KOH/g oil). In addition, peroxide value and anisidine index of sour cherry kernel oil were obtained as 0.99 meqO2/kg oil and 0.15, respectively. The predominant fatty acids were linoleic acid (42.34%), oleic acid (35.45%), α-eleostearic acid (9.34%), and palmitic acid (6.54%), respectively. The kernel oil contained nine major triacylglycerols consisting of OLL (20.44%), OOL (16.99%), LLL (8.20%), LLEl (7.28%), PLO (7.24%), OElO (5.03%), OOO (4.70%), ElLO (4.54%), PLL (4.35%), and POO (3%), respectively. The most abundant sterol compounds were β-sitosterol (83.55%), ∆5-avenasterol (6.8%), sitostanol (4.8%), campesterol (3.5%), and stigmasterol (0.53%), respectively. Also, antioxidant activity, total phenol content (TPC), total anthocyanin content (TAC), total flavonoid content (TFC), total tannin content (TTC), and total tocopherol content were obtained as 73.22%, 33.44 mg GA/g dry matter, 177.84 mg/L, 46.37 mg/g dry matter, and 1.21 mg GA/g dry matter, 832.5 mg/kg oil, respectively. The amount of amygdalin in the oil sample was not detectable.

Antioxidant, anti-inflammatory and cytotoxic activities of the unsaponifiable fraction of extra virgin olive oil

The health benefits of olive oil are well-known. In this study, the unsaponifiable fraction of extra virgin olive oil (Unsap) was investigated for reducing power capacity, ferric reducing antioxidant power, fer-rous chelating activity and nitric oxide inhibition. The present study was also designed to evaluate the in vitro cytotoxic effect of the Unsap against human carcinoma cells. The anti-inflammatory potential of Unsap has been determined via the inhibition of Human Cyclooxygenases. The results showed that Unsap is efficient for ferric reducing antioxidant power and nitric oxide inhibition. Unsap has a selective effect as anti-inflammatory agent. The results showed moderate to good in vitro antitumor activities of Unsap against human liver, lung and pancreas cancer cells with IC50 ranging from 19.6 to 30.4 μg/mL and good selectivity index (≥ 2). In conclusion, Unsap represents a promising and safe antitumor and antioxidant material that supports the need for further investigation.

Targeting Mitogen-Activated Protein Kinases by Natural Products: A Novel Therapeutic Approach for Inflammatory Bowel Diseases

An increase in the prevalence of Inflammatory Bowel Diseases (IBD) as a multifactorial intestinal chronic inflammation as well as the absence of a certain cure, has created an innovative era in the management of IBD by molecule/pathway-based anti-inflammatory approaches. There are credible documentations that demonstrate Mitogen-Activated Protein Kinases (MAPK) acts as IBD regulator. Upon the activation of MAPK signalling pathway, the transcription and expression of various encoding inflammatory molecules implicated in IBD are altered, thereby exacerbating the inflammation development. The current pharmacological management of IBD, including drug and biological therapies are expensive, possess temporary relief and some adverse effects. In this context, a variety of dietary fruits or medicinal herbs have received worldwide attention versus the development of IBD. Infact, natural ingredients, such as Flavaglines, Fisetin, Myricitrin, Cardamonin, Curcumin, Octacosanol and Mangiferin possess protective and therapeutic effects against IBD via modulation of different segments of MAPK signaling pathway. This review paper calls attention to the role of MAPK signaling triggered by natural products in the prevention and treatment of IBD.

Extra virgin olive oil and related by-products (Olea europaea L.) as natural sources of phenolic compounds for abdominal pain relief in gastrointestinal disorders in rats

Management of abdominal pain, a common symptom of IBDs and IBS, is still a clinical problem. Extra virgin olive oil (EVOO), a main component of the Mediterranean diet, shows positive effects on chronic inflammation in IBDs. In this study, the effect of the oral administration of EVOO (3 mL) and two olive milling by-products, DPA (300 mg kg^-1) and DRF (300 mg kg^-1), on preventing the development of abdominal pain in a DNBS-induced colitis model in rats was evaluated. The doses were chosen with the aim of simulating a plausible daily intake in humans. DPA and EVOO treatments significantly reduced the abdominal viscero-motor response to colon-rectal distension at 2 and 3 mL of balloon distension volume, both 7 and 14 days after the DNBS-injection. DRF showed efficacy in the reduction of visceral hypersensitivity only with 3 mL balloon inflation. In awake animals, DPA and DRF reduced pain perception (evaluated as abdominal withdrawal reflex) with all balloon distension volumes, while EVOO was effective only with higher distension volumes. Fourteen days after the DNBS-injection, all samples reduced the macroscopic intestinal damage (quantified as the macroscopic damage score) also showing, at the microscopic level, a reduction of the inflammatory infiltrate (quantified by hematoxylin and eosin analysis), fibrosis (highlighted by picrosirius red staining), the increase in mast cells and their degranulation (analyzed by triptase immunohistochemistry). This is the first report on the promotion of abdominal pain relief in a rat model obtained administering EVOO and two derived by-products. Our results suggest a protective role of phenol-rich EVOO and milling by-products, which may be proposed as food ingredients for novel functional foods.

The High-Fat Diet Based on Extra-Virgin Olive Oil Causes Dysbiosis Linked to Colorectal Cancer Prevention

The present study aims to examine the effects of three different high-fat diet (HFD) on mice gut microbiota in order to analyse whether they create the microenvironmental conditions that either promote or prevent colorectal cancer (CRC). We evaluated colonic mucosa-associated microbiota in CD1 mice fed with HFD, based on 60% kcal from fat-containing coconut, sunflower or extra-virgin olive oil as the only source of fat. The main findings were as follows: (a) All HFD produced a decrease in the richness and diversity of the intestinal microbiota that was independent of mouse weight, (b) HFD switched Lactobacillus to Lactococcus. In general, the results showed that both sunflower- and coconut-HFD generated a pro-inflammatory intestinal microenvironment. In brief, coconut-HFD decreased Akkermansia and increased Staphylococcus, Prevotella and Bacteroides spp. abundance. Sunflower-HFD reduced Akkermansia and Bifidobacterium, while enhancing Sphingomonas and Neisseria spp. abundance. In contrast, EVOO-HFD produced an anti-inflammatory microenvironment characterised by a decreased Enterococcus, Staphylococcus, Neisseria and Pseudomonas spp. abundance. At the same time, it increased the Firmicutes/Bacteroidetes ratio and maintained the Akkermansia population. To conclude, EVOO-HFD produced changes in the gut microbiota that are associated with the prevention of CRC, while coconut and sunflower-HFD caused changes associated with an increased risk of CRC.

A food pyramid, based on a review of the emerging literature, for subjects with inflammatory bowel disease

Emerging literature suggests that diet plays an important modulatory role in inflammatory bowel disease (IBD) through the management of inflammation and oxidative stress. The aim of this narrative review is to evaluate the evidence collected up till now regarding optimum diet therapy for IBD and to design a food pyramid for these patients. The pyramid shows that carbohydrates should be consumed every day (3 portions), together with tolerated fruits and vegetables (5 portions), yogurt (125ml), and extra virgin olive oil; weekly, fish (4 portions), white meat (3 portions), eggs (3 portions), pureed legumes (2 portions), seasoned cheeses (2 portions), and red or processed meats (once a week). At the top of the pyramid, there are two pennants: the red one means that subjects with IBD need some personalized supplementation and the black one means that there are some foods that are banned. The food pyramid makes it easier for patients to decide what they should eat.

Bacterioruberin from Haloarchaea plus dexamethasone in ultra-small macrophage-targeted nanoparticles as potential intestinal repairing agent

Oral administration of antioxidant and anti-inflammatory drugs have the potential to improve the current therapy of inflammatory bowel disease. Success of oral treatments, however, depends on the capacity of drugs to remain structurally stable along the gastrointestinal tract, and on the feasibility of accessing the target cells. Delivering anti-inflammatory and antioxidant drugs to macrophages using targeted nanoparticles, could make treatments more efficient. In this work structural features and in vitro activity of macrophage-targeted nanostructured archaeolipid carriers (NAC) containing the high antioxidant dipolar C50 carotenoid bacterioruberin (BR) plus dexamethasone (Dex): NAC-Dex, are described. Ultra-small (66 nm), -32 mV ζ potential, 1200 μg Dex /ml NAC-Dex, consisted of a compritol and BR core, covered by a shell of sn 2,3 ether linked archaeolipids and Tween 80 (2: 2: 1.2: 3 % w/w) were obtained. NAC-Dex were extensively captured by macrophages and Caco-2 cells and displayed high anti-inflammatory and antioxidant activities on a gut inflammation model made of Caco-2 cells and lipopolysaccharide stimulated THP-1 derived macrophages reducing 65 % and 55 % TNF-α and IL-8 release, respectively and 60 % reactive oxygen species production. NAC-Dex also reversed the morphological changes induced by inflammation and increased the transepithelial electrical resistance, partly reconstituting the barrier function. Activity of BR and Dex in NAC-Dex was partially protected after simulated gastrointestinal digestion, improving the chances of BR-Dex joint activity. Results suggest that oral NAC-Dex deserve further exploration as intestinal barrier repairing agent.

Extra virgin olive oil and flaxseed oil have no preventive effects on DSS-induced acute ulcerative colitis

OBJECTIVES

The aim of this study was to evaluate the preventive effects of extra virgin olive oil (EVOO) or flaxseed oil (FO) on dextran sodium sulfate (DSS)-induced acute ulcerative colitis in female mice.

METHODS

Eighty C57BL/6J mice of 8-weeks-old were divided in four groups: Control (SO), 10%EVOO, 10%FO and 5%EVOO+5%FO. The oils were given through the AIN-93M diet. After 30 days, animals were divided in four more groups, in which half received 3%DSS in water for 5 days. Body weight loss, bleeding and stool consistency were verified for the Disease Activity Index (DAI). Animals were euthanized and their colon and spleen weighted and measured. Histopathological analysis, the concentrations of TNF-α, IL-1β, and IL-10 and the iNOS expression were evaluated in the colon samples.

RESULTS

Animals that received DSS presented with elevated disease activity index values; increased colon weight-to-length ratio; augmented leukocyte infiltration into the lamina propria and submucosa; and increased production of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6, and greater inducible nitric oxide synthase expression in the distal colon. Individually or in combination, the oils were not able to reverse or mitigate any of the DSS-induced symptoms or damage. Additionally, the group of animals treated with DSS and supplemented with FO displayed increased spleen weight-to-body weight ratio, and the group that received a combination of EVOO and FO presented increased TNF-α levels compared with the respective control group.

CONCLUSION

Consumption of large amounts of EVOO and FO as a treatment for or prevention against ulcerative colitis could potentially elicit unwanted adverse effects.

The effects of extra virgin olive oil and canola oil on inflammatory markers and gastrointestinal symptoms in patients with ulcerative colitis

BACKGROUND/OBJECTIVES

Ulcerative colitis (UC) is an immune-mediated disease that causes inflammation in the gastrointestinal tract. Diet has an important role in the treatment of UC. This study aimed to compare the effects of extra virgin olive oil (EVOO), as a functional food, with canola oil in the treatment of UC.

SUBJECTS/METHODS

Forty patients were participating in this crossover clinical trial. Thirty two patients completed two intervention rounds. Blood samples were taken before and after 20 days intervention. Disease activity score and gastrointestinal symptoms were evaluated using the Mayo score and gastrointestinal symptom rating scale (GSRS) respectively.

RESULTS

Erythrocyte sedimentation rate (p = 0.03) and high-sensitivity C-reactive protein (p < 0.001) were decreased significantly after EVOO consumption. Bloating, constipation, fecal urgency, incomplete defecation, and final GSRS were reduced significantly after EVOO consumption (p < 0.05).

CONCLUSIONS

Intake of EVOO decreased the inflammatory markers and improved gastrointestinal symptoms in UC patients. It seems this functional food can be beneficial in the treatment of UC as a complementary medicine.

Virgin Olive Oil and Health: Summary of the III International Conference on Virgin Olive Oil and Health Consensus Report, JAEN (Spain) 2018

The Mediterranean diet is considered as the foremost dietary regimen and its adoption is associated with the prevention of degenerative diseases and an extended longevity. The preeminent features of the Mediterranean diet have been agreed upon and the consumption of olive oil stands out as the most peculiar one. Indeed, the use of olive oil as the nearly exclusive dietary fat is what mostly characterizes the Mediterranean area. Plenty of epidemiological studies have correlated that the consumption of olive oil was associated with better overall health. Indeed, extra virgin olive oil contains (poly)phenolic compounds that are being actively investigated for their purported biological and pharma-nutritional properties. On 18 and 19 May 2018, several experts convened in Jaen (Spain) to discuss the most recent research on the benefits of olive oil and its components. We reported a summary of that meeting (reviewing several topics related to olive oil, not limited to health) and concluded that substantial evidence is accruing to support the widespread opinion that extra virgin olive oil should, indeed, be the fat of choice when it comes to human health and sustainable agronomy.

Minor compounds from virgin olive oil attenuate LPS-induced inflammation via visfatin-related gene modulation on primary human monocytes

We have analyzed the effects of minor compounds found in the unsaponifiable fraction (UF) and in the phenolic fraction (PF) of virgin olive oil (VOO) on LPS-induced inflammatory response via visfatin modulation in human monocytes. For this purpose, monocytes were incubated with UF and PF at different concentrations and the pro-inflammatory stimulus LPS for 24 hr; squalene (SQ) and hydroxytyrosol (HTyr), the main components in UF and PF, respectively, were also used. The relative expression of both pro-inflammatory and anti-inflammatory genes, as well as other genes related to the NAD+-biosynthetic pathway was evaluated by RT-qPCR; and the secretion of some of these markers was assessed by ELISA procedures. We found that UF, SQ, PF, and HTyr prevented from LPS-induced dysfunctional gene expression and secretion via visfatin-related gene modulation in human monocytes. These findings unveil a potential beneficial role for minor compounds of VOO in the prevention of inflammatory-disorders. PRACTICAL APPLICATION: In this project, potential health benefits of VOO micronutrients (unsaponifiable and phenolic compounds) were confirmed through anti-inflammatory assays. Our results reveal new interesting researching goals concerning nutrition by considering the role of bioactive VOO compounds in the prevention and progress of diseases related to inflammation.

PGlyRP3 concerts with PPARγ to attenuate DSS-induced colitis in mice

Nutrients may modulate immunity through their transcription factors that act on both metabolic and immunity genes. It has been shown that the transcription factor of lipid ligands PPARγ physically binds the gene promoter of the peptidoglycan recognition protein (PGlyRP3), which showed anti-inflammatory action in vitro. It is hypothesized in the present work that olive oil feeding protects against toxicity of DSS-induced colitis via activation of the lipid transcription factor PPARγ that stimulates the anti-inflammatory PGlyRP3. Results: PGlyRP3 is expressed in mouse colon and up-regulated by olive oil feeding. Olive oil reduced mortality and severity scores of DSS-induced colitis and down-regulated the proinflammatory IL-1b, IL-6 and TNFα genes. This protective effect was accompanied by up-regulation of both PPARγ and PGlyRP3. Inhibition of PPARγ by its antagonist BADGE down-regulated PGlyRP3 and abolished the anti-inflammatory effect of olive oil feeding in this DSS-induced colitis model, reflecting the pivotal role of PPARγ binding nutrition and inflammation. Activation of PGlyRP3 by its ligand peptidoglycan was not responsible for the inflammation caused by peptidoglycan, since neutralization of TLR2 attenuated this inflammatory response without affecting the peptidoglycan-induced PGlyRP3 level. Olive oil activated the IκBα and inhibited NF-κB and cox-2 gene expressions, and p65 nuclear translocation in DSS-colitis mice, reflecting the involvement of the inhibition of NF-κB signaling pathway in the anti-inflammatory olive oil - PPARγ - PGlyRP3 access. This pathway was reactivated by the PPARγ antagonist BADGE. Conclusions: Olive oil regulates by the same transcription factor (PPARγ) both lipid metabolic and immune gene (PGlyRP3) expressions, exerting the anti-inflammatory effect, and protecting against DSS-induced colitis in mice.

Molecular interactions between 3,4-dihydroxyphenylglycol and pectin and antioxidant capacity of this complex in vitro

This study explored the interaction of pectin with 3,4-dihydroxyphenylglycol (DHPG), a potent phenolic antioxidant naturally found in olive fruit, via encapsulation into pectinate beads. MALDI TOF-TOF analysis supported the formation of complexes between DHPG and pectin. A combination of covalent bonds (ester bonds) and non-covalent interactions, mostly hydrogen bonding, were suggested as the cause of DHPG-pectin complex formation. Free radical scavenging assays confirmed that DHPG maintained its antioxidant activity after complexation and after a digestion simulated in vitro with gastric and intestinal fluids. Therefore, DHPG-pectin beads could reach the large intestine and contribute to a healthy antioxidant environment.

β-Sitosterol and stigmasterol ameliorate dextran sulfate sodium-induced colitis in mice fed a high fat Western-style diet

Phytosterols, the plant analogues of cholesterol, widely occur in the human diet. In this study, we investigated and compared the effects of stigmasterol and β-sitosterol (both with purities ≥95%) on dextran sulfate sodium (DSS)-induced colitis in C57BL/6J male mice fed a high fat Western-style diet. Mice treated with DSS developed severe mucosal colitis, with a marked distortion and crypt loss of colonic surface epithelium. Both β-sitosterol and stigmasterol significantly inhibited colon shortening, lowered fecal hemoglobin content, and reduced the severity of colitis in the middle and distal colon (p < 0.05). These phytosterols also significantly suppressed the activation of nuclear factor-kappa B. They also significantly decreased colony stimulating factor-1 and the nuclear translocation of inflammatory master regulator nuclear factor-kappa B. Stigmasterol significantly lowered the colonic inflammation score and the expression of cyclooxygenase-2 and colony stimulating factor-1, while β-sitosterol was less or not effective. These results suggest that dietary intake of stigmasterol and β-sitosterol ameliorates colitis. Such activities of stigmasterol and β-sitosterol in humans remain to be investigated.

Olive oil polyphenols reduce oxysterols -induced redox imbalance and pro-inflammatory response in intestinal cells

Dietary habits may strongly influence intestinal homeostasis. Oxysterols, the oxidized products of cholesterol present in cholesterol-containing foodstuffs, have been shown to exert pro-oxidant and pro-inflammatory effects, altering intestinal epithelial layer and thus contributing to the pathogenesis of human inflammatory bowel diseases and colon cancer. Extra virgin olive oil polyphenols possess antioxidant and anti-inflammatory properties, and concentrate in the intestinal lumen, where may help in preventing intestinal diseases. In the present study we evaluated the ability of an extra virgin olive oil phenolic extract to counteract the pro-oxidant and pro-inflammatory action of a representative mixture of dietary oxysterols in the human colon adenocarcinoma cell line (Caco-2) undergoing full differentiation into enterocyte-like cells. Oxysterols treatment significantly altered differentiated Caco-2 cells redox status, leading to oxidant species production and a decrease of GSH levels, after 1 h exposure, followed by an increase of cytokines production, IL-6 and IL-8, after 24 h. Oxysterol cell treatment also induced after 48 h an increase of NO release, due to the induction of iNOS. Pretreatment with the phenolic extract counteracted oxysterols effects, at least in part by modulating one of the main pathways activated in the cellular response to the action of oxysterols, the MAPK-NF-kB pathway. We demonstrated the ability of the phenolic extract to directly modulate p38 and JNK1/2 phosphorylation and activation of NF-kB, following its inhibitor IkB phosphorylation. The phenolic extract also inhibited iNOS induction, keeping NO concentration at the control level. Our results suggest a protective effect at intestinal level of extra virgin olive oil polyphenols, able to prevent or limit redox unbalance and the onset and progression of chronic intestinal inflammation.

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Dietary oxysterols exerted pro-oxidant and pro-inflammatory effects in differentiated Caco-2 cells.

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H₂O₂ production, GSH decrease, IL-6 and IL-8 release were detected.

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NO release due to iNOS induction was higher than controls in oxysterols treated cells.

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Olive oil phenolic extract efficiently counteracted oxysterols effects.

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Phenolic extract directly modulated p38 and JNK MAPK/NF-κB signaling axis.

Extra virgin olive oil: a key functional food for prevention of immune-inflammatory diseases

Nowadays, it is clear that an unhealthy diet is one of the prime factors that contributes to the rise of inflammatory diseases and autoimmunity in the populations of both developed and developing countries. The Mediterranean diet has been associated with a reduced incidence of certain pathologies related to chronic inflammation and the immune system. Olive oil, the principal source of dietary lipids of the Mediterranean diet, possesses a high nutritional quality and a particular composition, which is especially relevant in the case of Extra Virgin Olive Oil (EVOO). EVOO is obtained from olives solely by mechanical or other physical preparation methods, under conditions that do not alter the natural composition. EVOO is described as a key bioactive food with multiple beneficial properties and it may be effective in the management of some immune-inflammatory diseases. In this review, the key research is summarised which provides evidence of the beneficial effects of EVOO and its minor components focusing on their mechanisms on immune-inflammatory diseases such as rheumatoid arthritis, systemic lupus erythematosus, inflammatory bowel disease and sclerosis.

Modulation of intestinal epithelium homeostasis by extra virgin olive oil phenolic compounds

Extra virgin olive oil polyphenols concentrate at the intestinal level and, by modulating the microbiota, oxidative status and inflammation, contribute to prevent the onset or delay the progression of inflammatory/degenerative diseases.

Emu Oil Improves Clinical Indicators of Disease in a Mouse Model of Colitis-Associated Colorectal Cancer

BACKGROUND/AIMS

Ulcerative colitis is a remitting and relapsing inflammatory bowel disorder. Current treatments are limited, and if poorly controlled, colitis may progress to colorectal cancer. Previously, Emu Oil protected the intestine in experimental models of gut damage. We aimed to determine whether Emu Oil could reduce the severity of chronic colitis and prevent the onset of neoplasia in a mouse model of colitis-associated colorectal cancer.

METHODS

Female C57BL/6 mice were injected (day 0) with azoxymethane, followed by ad libitum access to three dextran sulfate sodium/water cycles (7 days of dextran sulfate sodium and 14 days of water). Mice (n = 9/group) were orally administered either water or Emu Oil (low dose 80 µL or high dose 160 µL), thrice weekly for 9 weeks. Bodyweight and disease activity index were measured daily. Colitis progression was monitored by colonoscopy on days 20, 41 and 62. At killing, tumor number and size were recorded.

RESULTS

Azoxymethane/dextran sulfate sodium induced significant bodyweight loss (maximum 24%) which was attenuated by Emu Oil treatment (low dose days 9, 10, 14: maximum 7%; high dose days 7-15, 30-36: maximum 11%; p < 0.05). Emu Oil reduced disease activity index of azoxymethane/dextran sulfate sodium mice at most time points (maximum 20%; p < 0.05). Additionally, Emu Oil reduced colonoscopically assessed colitis severity (days 20 and 62) compared to disease controls (p < 0.05). Finally, in azoxymethane/dextran sulfate sodium mice, low-dose Emu Oil resulted in fewer small colonic tumors (p < 0.05) compared to controls.

CONCLUSIONS

Emu Oil improved clinical indicators and reduced severity of colitis-associated colorectal cancer, suggesting therapeutic potential in colitis management.

Mediterranean Diet: Prevention of Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer diagnosis and the second and third leading cause of cancer mortality in men and women, respectively. However, the majority of CRC cases are the result of sporadic tumorigenesis via the adenoma–carcinoma sequence. This process can take up to 20 years, suggesting an important window of opportunity exists for prevention such as switching toward healthier dietary patterns. The Mediterranean diet (MD) is a dietary pattern associated with various health benefits including protection against cardiovascular disease, diabetes, obesity, and various cancers. In this article, we review publications available in the PubMed database within the last 10 years that report on the impact of a MD eating pattern on prevention of CRC. To assist the reader with interpretation of the results and discussion, we first introduce indexes and scoring systems commonly used to experimentally determine adherence to a MD, followed by a brief introduction of the influence of the MD pattern on inflammatory bowel disease, which predisposes to CRC. Finally, we discuss key biological mechanisms through which specific bioactive food components commonly present in the MD are proposed to prevent or delay the development of CRC. We close with a discussion of future research frontiers in CRC prevention with particular reference to the role of epigenetic mechanisms and microbiome related to the MD eating pattern.

The Impact of Western Diet and Nutrients on the Microbiota and Immune Response at Mucosal Interfaces

Recent findings point toward diet having a major impact on human health. Diets can either affect the gut microbiota resulting in alterations in the host’s physiological responses or by directly targeting the host response. The microbial community in the mammalian gut is a complex and dynamic system crucial for the development and maturation of both systemic and mucosal immune responses. Therefore, the complex interaction between available nutrients, the microbiota, and the immune system are central regulators in maintaining homeostasis and fighting against invading pathogens at mucosal sites. Westernized diet, defined as high dietary intake of saturated fats and sucrose and low intake of fiber, represent a growing health risk contributing to the increased occurrence of metabolic diseases, e.g., diabetes and obesity in countries adapting a westernized lifestyle. Inflammatory bowel diseases (IBD) and asthma are chronic mucosal inflammatory conditions of unknown etiology with increasing prevalence worldwide. These conditions have a multifactorial etiology including genetic factors, environmental factors, and dysregulated immune responses. Their increased prevalence cannot solely be attributed to genetic considerations implying that other factors such as diet can be a major contributor. Recent reports indicate that the gut microbiota and modifications thereof, due to a consumption of a diet high in saturated fats and low in fibers, can trigger factors regulating the development and/or progression of both conditions. While asthma is a disease of the airways, increasing evidence indicates a link between the gut and airways in disease development. Herein, we provide a comprehensive review on the impact of westernized diet and associated nutrients on immune cell responses and the microbiota and how these can influence the pathology of IBD and asthma.

Stability Profiles and Therapeutic Effect of Cu/Zn Superoxide Dismutase Chemically Coupled to O-Quaternary Chitosan Derivatives against Dextran Sodium Sulfate-Induced Colitis

Superoxide dismutase (SOD) has attracted considerable attention on treatment of reactive oxygen species (ROS)-related disorders. We previously conjugated Cu/Zn SOD to O-quaternary chitosan derivatives (O-HTCC) to yield a polymer–enzyme conjugate O-HTCC-SOD that demonstrated superior therapeutic effect to native SOD. The present study demonstrated that O-HTCC-SOD had wider pH activity range, better thermal stability, excellent long-term stability for storage, as well as unique reinstatement of activity exposure to proteolytic degradation that was helpful for longer half-life in vivo. O-HTCC-SOD exerted significant anti-inflammatory effects on lipopolysaccharides (LPS)-stimulated mouse peritoneal macrophages by down-regulating production of pro-inflammatory cytokines and intracellular ROS. O-HTCC-SOD significantly attenuated dextran sodium (DSS)-induced colitis in mice as observed by the colitis severity, neutrophil infiltration and histopathological damage, whereas native SOD failed to do so. In conclusion, conjugation of O-HTCC conferred SOD with better stability and enhanced therapeutic potential, offering a promising option in treatment of inflammatory bowel disease.

5-Aminosalicylic acid inhibits inflammatory responses by suppressing JNK and p38 activity in murine macrophages

CONTEXT

5-Aminosalicylic acid (5-ASA), as an anti-inflammatory drug, has been extensively used for the treatment of mild to moderate active ulcerative colitis (UC), but the possible mechanisms of action remain unclear.

OBJECTIVE

To investigate the effects of 5-ASA on the production of inflammatory mediators by murine macrophages stimulated with lipopolysaccharide (LPS), and determine the underlying pharmacological mechanism of action.

MATERIALS AND METHODS

The levels of nitric oxide (NO) and interleukin-6 (IL-6) were measured by Varioskan Flash and IL-6 Enzyme-Linked Immunosorbent Assay sets. Real time quantitative polymerase chain reaction was used to determine the level of induced nitric oxide synthase (iNOS). The effects of 5-ASA on iNOS, the c-Jun N-terminal kinases (JNKs), p38 and nuclear factor (NF)-κB signaling pathways were examined using western blotting.

RESULTS

5-ASA suppressed the production of NO and IL-6, and also decreased the expression of iNOS in LPS-induced RAW264.7 cells. 5-ASA inhibited the phosphorylation of JNKs and p38, but did not block NF-κB activation at all doses tested.

DISCUSSION AND CONCLUSION

The results indicated that the anti-inflammatory effect of 5-ASA was mainly regulated by the inhibition of the JNKs, p38 pathways rather than NF-κB pathway. Further research is required to clarify the detailed mechanism of the action.

Complexation of hydroxytyrosol and 3,4-dihydroxyphenylglycol with pectin and their potential use for colon targeting

Hydroxytyrosol (HT) and 3,4-dihydroxyphenylglycol (DHPG) are two phenolic antioxidants naturally found in olive fruit with anti-inflammatory properties. This study explored the interaction of pectin with HT and DHPG via their encapsulation into pectinate beads. Purification by size exclusion chromatography, changes in the fluorescence spectrum of the HT and pectin, and MALDI TOF-TOF analysis suggested the existence of the phenol-pectin complexes. The entrapment efficiency, swelling properties, and in vitro release of HT and DHPG of the beads were studied. The results show that the beads can entrap the water soluble compounds HT and DHPG in sufficient amounts to reach the colon. The beads consisted of an important amount of pectin-bound HT or DHPG after two hours at gastric pH. This study highlights the potential use of HT-and DHPG-loaded pectinate gel beads for the colon-targeted delivery of these bioactive compounds to help prevent or relieve chronic inflammatory bowel disease.

Dietary extra virgin olive oil attenuates kidney injury in pristane-induced SLE model via activation of HO-1/Nrf-2 antioxidant pathway and suppression of JAK/STAT, NF-κB and MAPK activation

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by a widespread organ involvement. Recent studies have suggested that extra virgin olive oil (EVOO) might possess preventive effects on this immunoinflammation-related disease. However, its role in SLE remained unknown. In this work, we evaluated the effects of EVOO diet in a pristane-induced SLE model in mice. Three-month-old mice received an injection of pristane or saline solution and were fed with different experimental diets: sunflower oil diet or EVOO diet. After 24weeks, mice were sacrificed, spleens were collected and kidneys were removed for immunoinflammatory detections. The kidney expression of microsomal prostaglandin E synthase 1, heme oxygenase 1 (HO-1), nuclear factor E2-related factor 2 (Nrf-2), mitogen-activated protein kinases (MAPKs), Janus kinase/signal transducer and activator of transcription (JAK/STAT) and nuclear transcription factor-kappa B (NF-κB) pathways were studied by western blotting. In addition to macroscopic and histological analyses, serum matrix metalloproteinase 3 (MMP-3) levels and proinflammatory cytokines production in splenocytes were evaluated by enzyme-linked immunoassay. We have demonstrated that EVOO diet significantly reduced renal damage and decreased MMP-3 serum and PGE2 kidney levels as well as the proinflammatory cytokines production in splenocytes. Our data indicate that Nrf-2 and HO-1 protein expressions were up-regulated in those mice fed with EVOO and the activation of JAK/STAT, MAPK and NF-κB pathways were drastically ameliorated. These results support the interest of EVOO as a beneficial functional food exerting a preventive/palliative role in the management of SLE.

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

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

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

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

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

Effects of dietary virgin olive oil polyphenols: hydroxytyrosyl acetate and 3, 4-dihydroxyphenylglycol on DSS-induced acute colitis in mice

Hydroxytyrosol, a polyphenolic compound from extra virgin olive oil (EVOO) has exhibited an improvement in a model of DSS-induced colitis. However, other phenolic compounds present such as hydroxytyrosyl acetate (HTy-Ac) and 3,4-dihydroxyphenylglycol (DHPG) need to be explored to complete the understanding of the overall effects of EVOO on inflammatory colon mucosa. This study was designed to evaluate the effect of both HTy-Ac and DHPG dietary supplementation in the inflammatory response associated to colitis model. Six-week-old mice were randomized in four dietary groups: sham and control groups received standard diet, and other two groups were fed with HTy-Ac and DHPG, respectively, at 0.1%. After 30 days, all groups except sham received 3% DSS in drinking water for 5 days followed by a regime of 5 days of water. Acute inflammation was evaluated by Disease Activity Index (DAI), histology and myeloperoxidase (MPO) activity. Colonic expression of iNOS, COX-2, MAPKs, NF-kB and FOXP3 were determined by western blotting. Only HTy-Ac-supplemented group showed a significant DAI reduction as well as an improvement of histological damage and MPO. COX-2 and iNOS protein expression were also significantly reduced. In addition, this dietary group down-regulated JNK phosphorylation and prevented the DSS-induced nuclear translocation level of p65. However, no significant differences were observed in the FOXP3 expression. These results demonstrated, for the first time, that HTy-Ac exerts an antiinflammatory effect on acute ulcerative colitis. We concluded that HTy-Ac supplement might provide a basis for developing a new dietary strategy for the prevention of ulcerative colitis.

Phytochemicals and their potential usefulness in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract with unclear etiology, namely ulcerative colitis and Crohn's disease. Various drug therapies including aminosalicylates and immunomodulators have been approved for use; they have shown to produce diverse side effects. To overcome these limitations of the current therapeutics for IBD, extensive research is underway to identify drugs that are effective and free of undesirable side effects. Recently, various naturally occurring phytochemicals that cover a wide range of chemical entities such as polyphenols, terpeniods, flavonoids, and alkaloids have received attention as alternative candidates for IBD therapy. These phytochemicals act by modulating the immune response, various transcription factors, or reduce cytokine secretion. This review summarizes the findings of recent studies on phytochemicals as therapeutic agents in the management of IBD.

Dietary squalene supplementation improves DSS-induced acute colitis by downregulating p38 MAPK and NFkB signaling pathways

SCOPE

Squalene is a polyunsaturated triterpene, which has exhibited anticancer and antioxidant activities among others. We investigated dietary squalene supplementation effect on an acute colitis model induced by dextran sulfate sodium (DSS) in C57BL/6 mice.

METHODS AND RESULTS

Mice were fed from weaning with squalene at 0.02% and 0.1%. After 4 weeks, mice were exposed to 3% DSS for 5 days developing acute colitis. After DSS removal (5 days), colons were histological and biochemically processed. Our results showed that dietary squalene treatment exerts anti-inflammatory action in DSS-induced acute colitis. Western blot revealed that squalene downregulated COX-2 (where COX is cyclooxygenase) and inducible nitric oxide synthase system by inhibition of mitogen-activated protein kinase p38 and the nuclear factor-kappa B signaling pathways, preventing an increase in the cytokines levels. Under our experimental conditions, STAT3 and FOXP3 (where FOXP3 is forkhead box P3) were not modified and the transcriptional regulation of antioxidant and/or detoxifying enzymes, Nrf2 (where Nrf2 is nuclear factor (erythroid-derived 2)-like 2), was reduced in DSS-induced colitis. However, any change could be observed after squalene supplementation.

CONCLUSION

Squalene was able to improve the oxidative events and returned proinflammatory proteins expression to basal levels probably through p38 mitogen-activated protein kinase and nuclear factor-kappa B signaling pathways. However, supplementary studies are needed in order to provide a basis for developing a new dietary supplementation strategy.

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

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

The unsaponifiable fraction of extra virgin olive oil promotes apoptosis and attenuates activation and homing properties of T cells from patients with inflammatory bowel disease

The unsaponifiable fraction (UF) of extra virgin olive oil (EVOO) possesses anti-inflammatory properties and exerts preventative effects in murine models of inflammatory bowel disease (IBD). The present study was designed to determine the in vitro effects of UF on blood and intestinal T cells from IBD patients and healthy subjects. The T cell phenotype was investigated by flow cytometry and cytokine secretion was determined by ELISA. The presence of UF of EVOO promoted apoptosis and attenuated activation of intestinal and blood T cells isolated from IBD patients, decreasing the frequency of CD69(+) and CD25(+) T cells and, also, the secretion of IFN-γ. Moreover, UF reduced the expression of the gut homing receptor integrin β7 on blood T cells from IBD patients. In conclusion, UF modulates the activity and the gut homing capacity of T cells, and might therefore be considered as a dietary complement with an anti-inflammatory role in IBD patients.

Review article: evidence-based dietary advice for patients with inflammatory bowel disease

BACKGROUND

The therapeutic effect of enteral nutrition in Crohn's disease (CD) and the epidemiological associations between diet and inflammatory bowel disease (IBD) implicate diet in IBD causation. There is little evidence, however, to support specific dietary changes and patients often receive contradictory advice.

AIM

To review the literature on the impacts of diet on IBD causation and activity to produce guidance based on 'best available evidence'.

METHOD

Review of Medline, Embase and Cochrane databases from 1975 to 2012 using MeSH headings 'crohn's disease' 'ulcerative colitis' 'enteral' 'diet' 'nutrition' 'fatty acid' and 'food additives'.

RESULTS

Enteral nutrition with a formula-defined feed is effective treatment for CD, but approximately 50% of patients relapse within 6 months of return to normal diet. There is no direct evidence of benefit from any other specific dietary modification in CD, but indirect evidence supports recommendation of a low intake of animal fat, insoluble fibre and processed fatty foods containing emulsifiers. Foods tolerated in sustained remission may not be tolerated following relapse. Some evidence supports vitamin D supplementation. In ulcerative colitis (UC), evidence is weaker, but high intakes of meat and margarine correlate with increased UC incidence and high meat intake also correlates with increased likelihood of relapse.

CONCLUSIONS

There is little evidence from interventional studies to support specific dietary recommendations. Nevertheless, people with IBD deserve advice based on 'best available evidence' rather than no advice at all, although dietary intake should not be inappropriately restrictive. Further interventional studies of dietary manipulation are urgently required.