Hyptis suaveolens (L.) Poit protects colon from TNBS-induced inflammation via immunomodulatory, antioxidant and anti-proliferative mechanisms

Ethnopharmacological relevance: In folk medicine Hyptis suaveolens (Lamiaceae) has been reported to relieve respiratory and gastrointestinal infections, indigestion, cold, pain, fever, cramps, skin diseases, gastric ulcer and inflammatory disorders. This study investigated the effects and the mechanisms of action of Hyptis suaveolens (L.) Poit (Lamiaceae) ethanol extract (Hs-EtOH) and hexane phase (Hs-HexF) against intestinal inflammation. Material and methods: Acute and relapse TNBS-induced ulcerative colitis protocols were used to evaluate intestinal anti-inflammatory activity. Damage evaluations, biochemical, histological and immunostaining parameters were determined. Results: Both extracts decreased macroscopic colonic inflammation and the area of lesion induced by TNBS. Nevertheless, only Hs-HexF was able to reduce colonic wall thickness, edema and diffuse inflammatory cell infiltration and to prevent GSH depletion in the acute model of ulcerative colitis. In the chronic phase with relapse of colonic ulceration, yet again only Hs-HexF significantly attenuated inflammatory parameters and presented a decrease in nitrite/nitrate, MDA, MPO, IL-1-beta and TNF-alpha and increased levels of SOD, CAT, GSH and IL-10. Hs-HexF also significantly reduced positive cells immunostained for PCNA. Conclusion: The data indicate intestinal anti-inflammatory activity for H. suaveolens, due to the participation of the antioxidant system, decreased neutrophil infiltration and cytokine modulation, as well as, owing to regulation of cell proliferation.