Protective effects of conventional and colon-targeted lycopene and linalool on ulcerative colitis induced by acetic acid in rats.

Objective: To compare the potential protective effects of conventional and colon-targeted lycopene (TLC) and linalool (TLN) on acetic acid (AA)-induced ulcerative colitis (UC) in rats.

Methods: Conventional and colon-targeted LC (10 mg/kg) and LN (200 mg/kg) were administered in vivo orally for 7 days and sulfasalazine (100 mg/kg) was also used as reference drug. Then, 4% AA was administered intrarectally to induce UC. Subsequently, the colon tissues were taken as samples for biochemical and histopathological analysis.

Results: Malondialdehyde (MDA), interleukin 1β (IL-1β), IL-6, cyclooxygenase-2 (COX-2) and nuclear factor kappa B (NF-κB) levels were decreased (p < 0.05) in the targeted groups compared to the AA group, whereas nuclear factor-erythroid 2-related factor 2 (Nrf-2) level was increased (p < 0.05). Tumor necrosis factor α (TNF-α) level was also decreased (p < 0.05) and catalase activity (CAT) was increased (p < 0.05) in the TLC group compared to the AA group. IL-1β and IL-6 levels were lower in the TLC group compared to the conventional LC and sulfasalazine groups (p < 0.05). COX-2 and NF-κB levels were lower, while the Nrf-2 level was higher in the targeted groups compared to the conventional groups (p < 0.05). Furthermore, COX-2 level was lower and Nrf-2 level was higher in the targeted groups compared to the sulfasalazine group (p < 0.05).

Conclusion: As expected, sulfasalazine was effective on all parameters analyzed, but the colon-targeted pretreatments were more effective from sulfasalazine on some parameters. Therefore, colon-targeted plant-derived therapies might be alternative approaches to provide protection against UC, which deserves to be investigated further.