Protective effect of Lactobacillus plantarum 21, a probiotic on trinitrobenzenesulfonic acid-induced ulcerative colitis in rats

• Lactobacillus plantarum 21 (LAB 21), a new strain of probiotic was able to ameliorate the TNBS induced colitis in rats.
• LAB21 relieved the oxidative stress by up-regulation of GSH levels and by down-regulation of TBARS and NO levels.
• LAB21 showed immunomodulatory properties by up-regulation of IL-10 with down-regulation of TNF-α and IL-1β.
• This observations suggests inclusion of LAB21 to the list of probiotics that have been reported to attenuate inflammation.
• LAB 21, a new strain of probiotic was able to ameliorate the TNBS induced colitis in rats.

Inflammatory mediators play a crucial role in ulcerative colitis (UC). The present study was aimed to evaluate the effects of Lactobacillus plantarum 21 (LAB 21) on inflammatory mediators in trinitrobenzenesulfonic acid (TNBS)-induced colitis in rats. The inflammatory response was assessed by changes in colon morphology, histopathology, and measurement of reduced glutathione (GSH), lipid peroxidation (TBARS), nitric oxide (NO), interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α), and interleukin 10 (IL-10) mRNA and protein levels by ELISA. Besides, protein expressions of IL-1β and IL-10 were also evaluated by western blot. Treatment with LAB 21 (1 × 1010 CFU/rat/day) and sulfasalazine (500 mg kg− 1 body weight) for 14 days after induction of colitis, significantly decreased TBARS, NO and increased GSH concentration. The protein and mRNA expressions of IL-1β and TNFα were down-regulated, whereas, protein and mRNA expression of IL-10 was up-regulated in LAB 21-treated rats. Moreover, LAB 21 attenuated the macroscopic colonic damage, histopathological changes induced by TNBS. These results suggest that LAB 21 may be effective in the treatment of UC by immunomodulatory and antioxidant properties.