Omega-3 Polyunsaturated Fatty Acids Counteract Inflammatory and Oxidative Damage of Non-Transformed Porcine Enterocytes

Abstract

Marine and plant-based omega-3 polyunsaturated fatty acids (ω-3 PUFAs) are widely added to animal diets to promote growth and immunity. We tested the hypothesis that eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and their 1:2 combination could counteract acute or long-term damage of lipopolysaccharides (LPS), dextran sodium sulphate (DSS) and hydrogen peroxide (H₂O₂) in Intestinal Porcine Epithelial Cell line-J2 (IPEC-J2). The results showed that 24 h treatment with EPA or DHA exhibited proliferative effects in IPEC-J2 cells at low to moderate concentrations (6.25-50 μM) (p < 0.05). Further, 24 h pretreatment with individual DHA (3.3 µM), EPA (6.7 µM) or as DHA:EPA (1:2; 10 µM) combination increased the mitochondrial activity or cell membrane integrity post-LPS (24 h), DSS (24 h) and H₂O₂ (1 h) challenge (p < 0.05). Additionally, DHA:EPA (1:2, 10 µM) combination decreased the apoptotic caspase-3/7 activity around twofold after 24 h LPS and DSS challenge (p < 0.05). Our study confirms the proliferative and cytoprotective properties of EPA and DHA in IPEC-J2 cells. Increased intracellular mitochondrial activity and cell membrane integrity by ω-3 PUFAs can play a role in preventing enterocyte apoptosis during acute or chronic inflammatory and oxidative stress.

Keywords: docosahexaenoic acid; eicosapentaenoic acid; omega-3 polyunsaturated fatty acids; porcine IPEC-J2 cells.

Figure 1

Dose–response effect of (a) eicosapentaenoic acid (EPA) and (b) docosahexaenoic acid (DHA) with different concentrations (0–200 µM) on the Intestinal Porcine Epithelial Cell line (IPEC-J2) viability for 24 h. Data are presented as mean ± SEM (n = 3, one-way ANOVA). Statistically significant differences among the treatments are denoted by different letters (a, b, c, d, e), where p < 0.05.

Figure 2

Dose–response effect of (a) lipopolysaccharide (LPS) (0–200 µM) for 24 h; (b) dextran sodium sulfate (DSS) (0–10%) for 24 h and (c) H₂O₂ (0–4 mM) for 1 h on IPEC-J2 viability. Data are presented as mean ± SEM (n = 3, one-way ANOVA). The 50% inhibitory concentrations (IC₅₀) were calculated by non-linear regression analysis and R² represents the goodness of fit.

Figure 3

Effects of DHA (3.3 µM), EPA (6.7 µM) and DHA:EPA (1:2; 10 µM) pre-treatment (24 h) on the viability of IPEC-J2 cells challenged by (a) LPS (50 or 100 µg/mL) for 24 h; (b) DSS (2%) for 24 h and (c) H₂O₂ (1 mM) for 1 h. Data are presented as mean ± SEM (n = 3, one-way ANOVA). Statistically significant differences among the treatments are denoted by different letters (a, b, c, d), where p < 0.05.

Figure 4

Effects of DHA (3.3 µM), EPA (6.7 µM) and DHA:EPA (1:2; 10 µM) pre-treatment (24 h) on the membrane integrity of IPEC-J2 cells challenged by (a) LPS (50 or 100 µg/mL) for 24 h; (b) DSS (2%) for 24 h and (c) H₂O₂ (1 mM) for 1 h. Data are presented as mean ± SEM (n = 3, one-way ANOVA). Statistically significant differences among the treatments are denoted by different letters (a, b, c, d), where p < 0.05.

Figure 5

Effects of DHA:EPA (1:2; 10 µM) pre-treatment (24 h) on the apoptosis of IPEC-J2 cells challenged by (a) LPS (50 or 100 µg/mL) and (b) DSS (2%) for 24 h. Data are presented as mean ± SEM (n = 3, one-way ANOVA). Statistically significant differences among the treatments are denoted by different letters (a, b, c), where p < 0.05.