Differential Effects of Dietary Oregano Essential Oil on the Inflammation Related Gene Expression in Peripheral Blood Mononuclear Cells From Outdoor and Indoor Reared Pigs

Abstract

Intensive farming systems represent a stressful environment for pigs and negatively influence neuroendocrine functions, behavior, and performance. Outdoor farming is an alternative option, which is thought to imply several beneficial effects for the animal. Dietary essential oils are known to be an innovative strategy to improve pig health and performance, and oregano essential oil (ORE) possesses beneficial effects due to its antimicrobial, anti-fungal, and antioxidant properties. We tested the effect of dietary ORE on peripheral blood mononuclear cells (PBMCs) in 36 growing pigs, either reared under indoor or outdoor conditions. Quantitative real-time PCR (RT-qPCR) assay was used to evaluate the effect of diet (control vs. ORE) and the time of sampling (T1−120 days vs. T2−190 days) on the expression of inflammatory and immune-related genes (TNF, IL1β, IL8, IL18, IL10, IL1RN, STAT3, HSP90, ICAM-1, and NFKB1). Under outdoor condition, the majority of transcripts were upregulated (p < 0.05), assuming a general inflammatory status (TNF, HSP90, NFKB1, IL1β, and STAT3). However, an interaction between diet and the farming system was observed: HSP90, NFKB1, and STAT3 were downregulated (p < 0.05) in the outdoor reared pigs when fed the ORE diet. Our study showed that bioactive compounds of ORE exert their activity, especially when the animals are exposed to stressful stimuli. Dietary ORE can be an acceptable strategy to help pigs tolerate the stress related to the harsh, outdoor, rearing conditions.

Chemical Composition and Biological Activities of Essential Oils from Origanum vulgare Genotypes Belonging to the Carvacrol and Thymol Chemotypes

“…Data reported in the literature relating to oregano EO anti-inflammatory activity suggest their ability to reduce inflammation in several in vitro and in vivo models [ 48 , 49 , 50 ]; however, in our intestinal Caco-2 cell system, pre-incubation with EOs did not induce evident protection from TNF-α inflammatory challenge. Nevertheless, CAR1 preincubation followed by TNF-α exposure determined a weak downregulation of genes involved in the NF-kB pathway.…”

Oregano Essential Oils Mediated Intestinal Microbiota and Metabolites and Improved Growth Performance and Intestinal Barrier Function in Sheep

“…There is an increasing interest in the usage of dietary OEO and LR for antibiotic-free livestock to improve growth, health status, immune responses, and modulate the gut microbiome ( 14 , 26 – 29 ). As expected, the data presented here show that OEO and LR supplementation improved ADG and decreased F/G ratio, which was in accordance with previous studies ( 30 , 31 ).…”

Pharmacological Applications and Action Mechanisms of Phytochemicals as Alternatives to Antibiotics in Pig Production

“…ORE treatment alters the lymphocyte proportion and the ratio of CD4 + and CD8 + T-cells in the serum of non-stimulated and in LPS-stimulated piglets ( 134 ). NF-κB is downregulated on peripheral blood mononuclear cells (PBMCs) in outdoor reared pigs when fed the ORE diet ( 135 ). Leukocyte populations in blood reveal that the percentages of Th lymphocytes, γδ T lymphocytes, and B lymphocytes are more affected by body weight in weanling piglets.…”