Anti-inflammatory effects of monoterpenoids in rats with TNBS-induced colitis

[Display omitted] •This study employed TNBS-induced colitis rats.•Diets supplemented with limonene-1,2-diol, R-(+)- and S-(–)-α-terpineol.•Monoterpenoids consumption significantly reduced colon TNF-α levels.•In general, the effects of R-(+)- and S-(–)-α-terpineol were comparable. Ulcerative colitis is an idiopathic disease, characterized by an inflammation of the intestinal mucosa. Considering that the dietary pattern can be related to both its occurrence and its protection, studies with food terpenoids have been conducted, indicating that such compounds present an anti-inflammatory effect in experimental models. The present study evaluated the effect of AIN-93 G diets supplemented (1470 mg/kg) with different enantiomers (R-(+)- and S-(–)-) of α-terpineol and limonene-1,2-diol on TNBS-induced colitis in male Wistar rats. The colon was analyzed in terms of: assessment of tissue damage, levels of cytokines, antioxidant status, besides gene expression of tight junction proteins, pro- and anti-inflammatory cytokines. Anti-inflammatory effect was observed, since monoterpenoid consumption reduced the TNF-α levels up to five times, in most groups. Moreover, supplemented diets, particularly with S-(–)-α-terpineol and limonene-1,2-diol, promoted a significant increase in gene expression of the anti-inflammatory cytokine IL-10. In general, no significant differences were observed between the effects of α-terpineol enantiomers. The results described in this article encourage future studies on the use of monoterpenoids to help treat colitis and inflammatory diseases.