Inflammatory bowel disease (IBD) is a chronic and idiopathic disease with gastrointestinal dysfunction. Current therapeutic approaches in IBD have several limitations such as, harmful side effects and high price for biologic drugs. It sounds that finding of an effective, safe and inexpensive strategy to overcome IBD is critical. Platelet derivatives, as biological pool of wide range of growth factors and cytokines, are widely used in regenerative medicine for treatment of soft and hard tissue lesions. We sought to determine whether platelet lysate (PL) alone or in combination with sulfasalazine (reference drug) can be a valuable strategy for overcoming IBD. In the present study, we investigated and compared the daily and alternate-day administration of PL alone or combined with sulfasalazine for treating colitis in a rat model of IBD. Histological damage scores of TNBS-induced colitis were reduced by co-administration of every alternate day PL and sulfasalazine. Pro-inflammatory cytokines TNF-α, IL-1 and IL-6 were decreased and anti-inflammatory cytokines IL-10 and TGF-β were increased after treatment with PL compared to that in the TNBS group. Furthermore, combined treatment with PL and sulfasalazine decreased apoptosis and inhibited the NF‐κB signaling pathway. In conclusion, the combined administration of PL with conventional IBD therapy is able to effectively ameliorate IBD through modulation of inflammatory status.