The Expression of Selected Cytokine Genes in the Livers of Young Castrated Bucks after Supplementation with a Mixture of Dry Curcuma longa and Rosmarinus officinalis Extracts

Abstract

The study aims to determine the effect of supplementation with a mixture of Curcuma longa and Rosmarinus officinalis extracts (896:19 ratio) on the expression of 15 cytokine genes in the livers of 20 castrated goat bucks. Two equal groups were created: treated and control groups. The treated group was provided a mixture (1.6 g/day/buck) for 124 days. Liver tissue samples were collected after slaughter. The gene expression was analyzed using RT-qPCR with two reference genes. Variance analysis was conducted using a model with the group fixed effect. IL-2 and IL-8 expression was below the detection level. No differences were found for IL-1α, IL-1β, IL-4, IL-6, IL-10, IL-16, IFN-α, IFN-β, TNF-α, and CCL4 expressions, suggesting that supplementation does not activate cytokine production in the healthy hepatocytes. The treated group demonstrated lower IL-12 expression (p < 0.05) and a tendency for higher IL-18 and INF-γ (0.05 < p < 0.10) expressions, which may indicate a hypersensitivity resulting from excessive supplement dose. The increased IFN-γ expression could be caused by the increased IL-18 expression. If a small dose of extract can induce an allergic reaction in young goat bucks, it is also possible that humans may be susceptible to an overdose of curcumin and/or turmeric extracts.

Keywords: castrated buck; cytokines; gene expression; liver; turmeric-rosemary mixture.

Figure 1

Timeline of the experiment.

Figure 2

The expression of the studied genes (natural logarithm from normalized gene expressions using two references) in the liver of bucks from the treated and control groups. IL-1α—Interleukin-1α; IL-1β—Interleukin-1β; IL-4—Interleukin 4; IL-6—Interleukin 6; IL-10—Interleukin 10; IL-16—Interleukin 16; IFN-α—Interferon α; IFN-β—Interferon β; TNF-α—Tumor necrosis factor α; CCL4—Chemokine 4. For all traits p > 0.1.

Figure 3

The differences in the relative expression of the selected genes (natural logarithm from normalized gene expressions using two references) between the treated and the control groups. a, b—different letters indicate the significance of differences at p ≤ 0.05. &, #—the significance of differences at 0.05 < p ≤ 0.10. IL-12—Interleukin-12; IL-18—Interleukin-18; IFN-γ—Interferon γ.