Phytic acid protects porcine intestinal epithelial cells from deoxynivalenol (DON) cytotoxicity

G. A, Al-Rawi AM, Nassar R, Islam MS. Phytic acid effect on periodontal ligament fibroblast: An in-vitro study

OBJECTIVES

This study evaluated phytic acid (IP6) effect on the viability, alkaline phosphatase (ALP) activity and calcium release of human periodontal ligament (HPDL) cells in optimal (OGL) and elevated glucose level (EGL) in cell culture media.

MATERIALS AND METHODS

Cells were seeded in OGL (1000mg/L) or EGL (4500 mg/L) media. IP6 was added at 0.005%, 0.01% or 0.02% concentrations for 24 or 48h, and XTT assay was performed. Cell differentiation and calcium release in presence of 0.02% IP6 in OGL or EGL in non-osteogenic or osteogenic media were analyzed using ALP assay and alizarin red staining, respectively.

RESULTS

In OGL, IP6 enhanced the viability of the cells at both exposure times (P<0.05). However, IP6 lowered the viability of the cells with the presence of EGL compared to the control at both exposure times, except for 0.02% IP6 which showed comparable viability to the control at 48 h. In OGL and EGL, ALP activity of the cells was not affected by the presence of IP6 in non-osteogenic media; however, in osteogenic media IP6 lowered the ALP activity. Meanwhile, calcium release was the highest with IP6 within osteogenic media of EGL.

CONCLUSIONS

IP6 effects on the HPDL cells were dependent on IP6 concentration, time of exposure, glucose levels and the osteogenic condition of the media.

CLINICAL RELEVANCE

This study gives insights on the potential therapeutic effect of IP6 as adjunctive periodontal therapy in patients with diabetes.

Progress on Gut Health Maintenance and Antibiotic Alternatives in Broiler Chicken Production

The perturbation of gut health is a common yet unresolved problem in broiler chicken production. Antibiotics used as growth promoters have remarkably improved the broiler production industry with high feed conversion efficiency and reduced intestinal problems. However, the misuse of antibiotics has also led to the increase in the development of antibiotic resistance and antibiotic residues in the meat. Many countries have enacted laws prohibiting the use of antibiotics in livestock production because of the increasing concerns from the consumers and the public. Consequently, one of the most significant discussions in the poultry industry is currently antibiotic-free livestock production. However, the biggest challenge in animal husbandry globally is the complete removal of antibiotics. The necessity to venture into antibiotic-free production has led researchers to look for alternatives to antibiotics in broiler chicken production. Many strategies can be used to replace the use of antibiotics in broiler farming. In recent years, many studies have been conducted to identify functional feed additives with similar beneficial effects as antibiotic growth promoters. Attention has been focused on prebiotics, probiotics, organic acids, emulsifiers, enzymes, essential oils, tributyrin, and medium-chain fatty acids. In this review, we focused on recent discoveries on gut health maintenance through the use of these functional feed additives as alternatives to antibiotics in the past 10 years to provide novel insights into the design of antibiotic-free feeds.

Phytic acid modulates the morphology, immunological response of cytokines and β-defensins in porcine intestine exposed to deoxynivalenol and fumonisin B1

Occurrence of mycotoxins in agricultural products represents a risk for human and animal health. Therefore, there is a requirement of strategies to mitigate their harmful impacts. This study investigated the effects of phytic acid (IP6) on the immunological response of pro-(interleukin (IL)-1β, IL-6, IL-8, IL-10, interferon (IFN)-γ, tumour necrosis factor (TNF)-α) and anti-inflammatory (IL-10) cytokines and β-defensins 1 (pBD-1) and 2 (pBD-2) in porcine jejunal explants exposed to deoxynivalenol (DON) and fumonisin B1 (FB1). The explants were exposed to the following treatments: control, DON (10 μM), DON plus IP6 2.5 mM or 5 mM, FB1 (70 μM), FB1 IP6 plus 2.5 or 5 mM. The expression levels of the cytokines were measured by RT-qPCR. The exposure to FB1 and DON induced intestinal lesions. The presence of 2.5 and 5 mM IP6 inhibited the morphological changes induced by the mycotoxins. The explants exposed to DON showed an increase in the expression of IL-1β and IL-8 and a decrease in the levels of IL-6, IFN-γ, IL-10 and pBD-2. IP6 (5 mM) decreased the expression of IL-8 and increased the expression in pBD-1 and 2 compared to DON alone. FB1 induced a significant decrease in the levels of most of the pro-inflammatory cytokines, IL-10 and pBD-1, and an increase in IL-1β expression. The addition of IP6 5 mM induced significant increase in TNF-α expression compared to FB1. Taken together, the results suggest IP6 modulates immunological changes induced by DON and FB1 on intestinal mucosa resulting in beneficial effects that contribute to intestinal homeostasis and health.

Mechanism of deoxynivalenol mediated gastrointestinal toxicity: Insights from mitochondrial dysfunction

Deoxynivalenol (DON) is a mycotoxin predominantly produced by Fusarium genus, and widely contaminates cereals and associated products all over the world. The intestinal toxicity of DON is well established. However, intestinal homeostasis involves mitochondria, which has rarely been considered in the context of DON exposure. We summarize the recent knowledge on mitochondria as a key player in maintaining intestinal homeostasis based on their functions in cellular energy metabolism, redox homeostasis, apoptosis, intestinal immune responses, and orchestrated bidirectional cross-talk with gut microbe. In addition, we discuss the pivotal roles of mitochondrial dysfunction in the intestinal toxicity of DON and highlight promising mitochondrial-targeted therapeutics for DON-induced intestinal injury. Recent studies support that the intestinal toxicity of DON is attributed to mitochondrial dysfunction as a critical factor. Mitochondrial dysfunction characterized by failure in respiratory capacities and ROS overproduction has been demonstrated in intestinal cells exposed to DON. Perturbation of mitochondrial respiration leading to ROS accumulation is implicated in the early initiation of apoptosis. DON-induced intestinal inflammatory response is tightly linked to the mitochondrial ROS, whereas immunosuppression is intimately associated with mitophagy inhibition. DON perturbs the orchestrated bidirectional cross-talk between gut microbe and host mitochondria, which may be involved in DON-induced intestinal toxicity.

Phytic Acid Decreases Oxidative Stress and Intestinal Lesions Induced by Fumonisin B₁ and Deoxynivalenol in Intestinal Explants of Pigs

The purpose of the present study was to investigate the effects of phytic acid (IP6) on morphological and immunohistochemical parameters and oxidative stress response in intestinal explants of pigs exposed to fumonisin B₁ (FB₁) and/or deoxynivalenol (DON). The jejunal explants were exposed to the following treatments: vehicle, IP6 5 mM, DON 10 µM, FB₁ 70 µM, DON 10 µM + FB₁ 70 µM, DON 10 µM + IP6 5 mM, FB₁ 70 µM + IP6 5 mM, and DON 10 µM + FB₁ 70 µM + IP6 5 mM. The decrease in villus height and goblet cell density was more evident in DON and DON + FB₁ treatments. In addition, a significant increase in cell apoptosis and cell proliferation and a decrease in E-cadherin expression were observed in the same groups. DON and FB₁ exposure increased cyclooxygenase-2 expression and decreased the cellular antioxidant capacity. An increase in lipid peroxidation was observed in DON- and FB₁-treated groups. IP6 showed beneficial effects, such as a reduction in intestinal morphological changes, cell apoptosis, cell proliferation, and cyclooxygenase-2 expression, and an increase in E-cadherin expression when compared with DON, FB₁ alone, or DON and FB₁ in association. IP6 inhibited oxidative stress and increased the antioxidant capacity in the explants exposed to mycotoxins.

Phytic acid improves intestinal mucosal barrier damage and reduces serum levels of proinflammatory cytokines in a 1,2-dimethylhydrazine-induced rat colorectal cancer model

Phytic acid (PA) has been demonstrated to have a potent anticarcinogenic activity against colorectal cancer (CRC). Defects of the intestinal mucosal barrier and inflammation processes are involved in the development and progression of CRC. In the present study, we evaluated the effect of PA on the intestinal mucosal barrier and proinflammatory cytokines. After a 1-week acclimatisation period, sixty Wistar male rats were divided into the following five groups, with twelve rats per group: the control group (CG), model group (MG), low-PA-dose group (0·25 g/kg per d), middle-PA-dose group (0·5 g/kg per d), and high-PA-dose group (1 g/kg per d). 1,2-Dimethylhydrazine (DMH) at a dosage of 30 mg/kg of body weight was injected weekly to induce CRC for 18 weeks. We examined the expression of genes related to the intestinal mucosal barrier in the model. The results demonstrated that tumour incidence was decreased following PA treatment. The mRNA and protein expression of mucin 2 (MUC2), trefoil factor 3 (TFF3) and E-cadherin in the MG were significantly lower than those in the CG (P<0·05). The mRNA and protein expression of claudin-1 in the MG were significantly higher than those in the CG (P<0·05). PA elevated the mRNA and protein expression of MUC2, TFF3 and E-cadherin, and diminished the mRNA and protein expression of claudin-1. Furthermore, PA decreased serum levels of proinflammatory cytokines, which included TNF-α, IL-1β and IL-6. In conclusion, this study suggests that PA has favourable effects on the intestinal mucosal barrier and may reduce serum proinflammatory cytokine levels.

Mycotoxins and oxidative stress: where are we?

Mycotoxins are the most common contaminants of food and feed worldwide and are considered an important risk factor for human and animal health. Oxidative stress occurs in cells when the concentration of reactive oxygen species exceeds the cell’s antioxidant capacity. Oxidative stress causes DNA damage, enhances lipid peroxidation, protein damage and cell death. This review addresses the toxicity of the major mycotoxins, especially aflatoxin B1, deoxynivalenol, nivalenol, T-2 toxin, fumonisin B1, ochratoxin, patulin and zearalenone, in relation to oxidative stress. It summarises the data associated with oxidative stress as a plausible mechanism for mycotoxin-induced toxicity. Given the contamination caused by mycotoxins worldwide, the protective effects of a variety of natural compounds due to their antioxidant capacities have been evaluated. We review data on the ability of vitamins, flavonoids, crocin, curcumin, green tea, lycopene, phytic acid, L-carnitine, melatonin, minerals and mixtures of anti-oxidants to mitigate the toxic effect of mycotoxins associated with oxidative stress.

Lactobacillus plantarum culture supernatants improve intestinal tissue exposed to deoxynivalenol

In the present study, histological, morphometrical and ultrastructural analysis were performed to investigate intestinal mucosa changes in piglets exposed to deoxynivalenol alone or associated with two strains of Lactobacillus plantarum and the respective culture supernatants. Jejunal explants were incubated for 4h in culture medium with a) only culture medium (DMEM, control group), b) deoxynivalenol (DON, 10μM), c) heat-inactivated Lactobacillus plantarum strain1 - LP1 (1.1×10⁸ CFU/ml) plus DON, d) heat-inactivated Lactobacillus plantarum strain2-LP2 (2.0×10⁹ CFU/ml) plus DON, e) heat-inactivated Lactobacillus plantarum strain1 culture supernatant (CS1) plus DON, and f) heat-inactivated Lactobacillus plantarum strain1 culture supernatant (CS1) plus DON. Explants exposed to DON and DON plus LP1 and LP2 showed a significant increase in histological changes (mainly villi atrophy and apical necrosis) and a significant decrease in villi height when compared to unexposed explants. However, explants treated with CS1+DON and CS2+DON remained similar to the control group both in histological and morphometrical aspects. DON also induced a significant decrease in goblet cell density compared to control whereas CS1+DON treatment induced an increase in the number of goblet cells in comparison to DON explants. In addition, ultrastructural assessment showed control, CS1+DON and CS2+DON explants with well delineated finger shape villi, meanwhile DON-treated, LP1+DON and LP2+DON explants showed a severe villi atrophy with leukocytes exudation on the intestinal surface. Taken together, our results indicate that the culture supernatant treatment reduced the toxic effects induced by DON on intestinal tissue and may contribute as an alternative strategy to reduce mycotoxin toxicity.

Deoxynivalenol induces toxic effects in the ovaries of pigs: An ex vivo approach

Deoxynivalenol (DON) is a frequently found trichothecene mycotoxin that elicits toxic effects on humans and animals. In pigs, DON induces changes in digestive and immune systems. Effects on the reproductive system are scarce and mainly based in in vitro models. The aim of this study was to evaluate, using an ex vivo model, the effects of DON on the morphology of ovaries of pigs in all stages of follicular development. Six 5-month-old pigs were used for sampling the explants. Thirty-six explants were incubated for 48 hours in culture medium (n = 18) or medium containing 10 μM of DON (n = 18). After the incubation period, the explants were submitted to histologic and immunohistochemical (proliferating cell nuclear antigen [PCNA] expression) analysis. Histologic changes were scored, and a lesional score was established. Oocytes and follicular cells immunostained for PCNA were counted. Explants exposed to DON showed a significant increase in the lesional score (P = 0.0004) compared to control explants. The main histologic changes were degeneration of oocytes and granulosa cells, interstitial edema and pyknotic cells. DON induced a reduction in the number of normal follicles in all stages of follicular development: primordial (P = 0.005), primary (P = 0.04), and growing follicles (P = 0.04) compared to control group. Deoxynivalenol also induced a significant increase (P ≤ 0.05) in the number of pyknotic oocytes in all stages of follicular development; however, no significant change in PCNA expression in oocytes or follicular cells was observed. These results indicated that DON induces toxic effects on the ovaries, affecting follicular development and interfering with reproductive parameters on pigs. Also, the present data indicate that ovarian explants are an adequate model for assessing reproductive toxicity.

Early Activation of MAPK p44/42 Is Partially Involved in DON-Induced Disruption of the Intestinal Barrier Function and Tight Junction Network

Deoxynivalenol (DON), produced by the plant pathogens Fusarium graminearum and Fusarium culmorum, is one of the most common mycotoxins, contaminating cereal and cereal-derived products. Although worldwide contamination of food and feed poses health threats to humans and animals, pigs are particularly susceptible to this mycotoxin. DON derivatives, such as deepoxy-deoxynivalenol (DOM-1), are produced by bacterial transformation of certain intestinal bacteria, which are naturally occurring or applied as feed additives. Intestinal epithelial cells are the initial barrier against these food- and feed-borne toxins. The present study confirms DON-induced activation of MAPK p44/42 and inhibition of p44/42 by MAPK-inhibitor U0126 monoethanolate. Influence of DON and DOM-1 on transepithelial electrical resistance (TEER), viability and expression of seven tight junction proteins (TJ), as well as the potential of U0126 to counteract DON-induced effects, was assessed. While DOM-1 showed no effect, DON significantly reduced TEER of differentiated IPEC-J2 and decreased expression of claudin-1 and -3, while leaving claudin-4; ZO-1, -2, and -3 and occludin unaffected. Inhibition of p44/42 counteracted DON-induced TEER decrease and restored claudin-3, but not claudin-1 expression. Therefore, effects of DON on TEER and claudin-3 are at least partially p44/42 mediated, while effects on viability and claudin-1 are likely mediated via alternative pathways.

Phytic Acid: From Antinutritional to Multiple Protection Factor of Organic Systems

Several studies have shown the benefits of natural antioxidants on health and food preservation. Phytic acid (IP6) is a natural antioxidant that is found mainly in cereals and vegetables and, for a long period of time, was considered an antinutritional factor. However, in vitro and in vivo studies have demonstrated its beneficial effects in the prevention and treatment of several pathological conditions and cancer. Despite the numerous benefits of IP6, the signs and intracellular interactions mediated by this antioxidant remain poorly understood. This review describes the main chemical and biological aspects of IP6, as well as its actions in the prevention and treatment of various diseases.

Phytic acid decreases deoxynivalenol and fumonisin B1-induced changes on swine jejunal explants

The purpose of the present study was to investigate the effects of phytic acid (IP6) on morphological and immunohistochemical parameters on intestinal explants exposed to deoxynivalenol (DON) and fumonisin B1 (FB1). The jejunal explants were exposed for 4 h to different treatments: control, DON (10 μM), DON plus 2.5 mM or 5 mM IP6, FB1 (70 μM), and FB1 plus 2.5 mM or 5 mM IP6. Both mycotoxins induced significant intestinal lesions and decreased villi height. The presence of 2.5 mM and 5 mM IP6 significantly inhibited the morphological changes caused by the mycotoxins. DON induced a significant increase in caspase-3 (83%) and cyclooxygenase-2 (71.3%) expression compared with the control. The presence of 5 mM IP6 induced a significant decrease in caspase-3 (43.7%) and Cox-2 (48%) expression compared with the DON group. FB1 induced a significant increase in caspase-3 expression (47%) compared to the control, whereas IP6 induced no significant change in this expression. A significant decrease in cell proliferation was observed when explants were exposed to 5 mM of IP6 in comparison with the DON and FB1 groups. The present data provide evidence that phytic acid modulates the toxic effects induced by DON and FB1 on intestinal tissue.