The Anti-oxidant Monoterpene p-Cymene Reduced the Occurrence of Colorectal Cancer in a Hyperlipidemia Rat Model by Reducing Oxidative Stress and Expression of Inflammatory Cytokines

Abstract

Background/aim: Overexpression of inflammatory cytokines and oxidative stress increase the risk of colorectal cancer (CRC) in obesity and hyperlipidemia. The aim of this study was to investigate whether the monoterpene antioxidant p-cymene would reduce the incidence of CRC in a rat model of hyperlipidemia.

Materials and methods: The hyperlipidemic CRC rat model was established by a high-fat diet and dimethyl hydrazine (DMH) induction. All rats received 30 mg/kg DMH to induce CRC, and were then assigned to groups with a normal diet or high-fat diet with/without 30 mg/kg/day p-cymene orally during the entire experimental period. Tumor incidence in each group, and the level of serum inflammatory cytokines and oxidative stress-related markers in intestinal tissues were measured.

Results: p-Cymene significantly inhibited CRC occurrence in hyperlipemic rats (p=0.024) by reducing the expression of serum inflammatory cytokines (interleukin-1 by 54.5%; interleukin-6 by 28.3%; adiponectin by 26.3%; cyclo-oxygenase-2 by 48.4%) and intestinal oxidative-stress cytokines (total antioxidant capacity by 30.4%; superoxide dismutase by 30.3%; malondialdehyde by 47.1%).

Conclusion: p-Cymene has clinical potential to reduce the incidence of CRC in hyperlipemia.

Keywords: antioxidant; colorectal cancer; cytokines; high-fat diet; hyperlipemia; inflammatory; p-Cymene; rat.