Ocimum gratissimum Linn. (Lamiaceae) protects wistar rats against inflammation and oxidative stress in trinitrobenzene sulfonic acid-induced colitis

Abstract

Background and Aim: The activity of methanol extract of leaf of Ocimum gratissimum a plant with anti-inflammatory, antioxidant, and anti-ulcerogenic activities in a rat model of colitis was evaluated. Experimental Procedures: Colitis was induced in 30 of 35 female Wistar rats by intracolonic instillation of 0.25 mL of 40 mg/mL 2, 4, 6-trinitrobenzene sulfonic acid (TNBS). The rats (180-200 g) were distributed into seven groups (n = 5): Non-colitic, untreated colitic, and colitic rats treated with prednisolone (2 mg/kg, for 7 days) or pre-treated 2 days before induction of colitis with O. gratissimum (50-400 mg/kg) and for additional 7 days post-colitis. Colonic levels of biomarkers of oxidative stress, pro-inflammatory cytokine tumor necrosis factor (TNF-α), myeloperoxidase (MPO) activity, and histology were assessed 24 h post-treatment in euthanized rats. Results: O. gratissimum at 400 mg/kg produced the highest reduction in colonic damage score, weight/length ratio, malondialdehyde level, TNF-α level, leukocytes infiltration (MPO activity), and prevented reduction of colonic glutathione level compared to prednisolone and other doses of O. gratissimum in colitic rats (P < 0.05). Conclusion: O. gratissimum ameliorates TNBS-induced colitis through inhibition of leukocytes infiltration, downregulation of cytokines, and scavenging of free radicals.