The novel piperazino-enaminone JOAB-40 reduced colitis severity in mice via inhibition tumor necrosis factor- and interleukin-1

Brief introduction: The synthetic compound enaminone E121 has an established role as a potent anti-tussive, bronchodilator and anti-inflammatory agent in asthma, cough, and colitis induced animal models. The addition of an N-alkylated piperazine motif to the terminal end of E121 lead to the generation of various analogues such as JOAB-40. JOAB-40 was shown to be more potent than the lead compound E121 in inhibiting the expression of the chemokine receptor CCR2, ERK1/2 phosphorylation, and the release of pro-inflammatory cytokines in vitro. Main objective of the study: We hypothesize that JOAB-40 is more potent than the lead compound E121 in reducing colitis severity in mice in part through inhibiting the release of TNF alpha and IL-1 beta. Methods: Colitis was induced by dextran sulfate sodium (DSS) administration using prophylactic and treatment approaches. The severity of the inflammation was determined by the gross (macroscopic) and histological (microscopic) assessments. The levels of TNF alpha, IL-1 beta, and IL-10 release in response to lipopolysaccharide (LPS) stimulation from the adherent murine macrophage cell line J774.2 in vitro, and the circulating levels of TNF alpha in vivo was measured by ELISA-based technique. Significant findings from the study: E121 administration (1-60 mg/kg) in mice with established colitis (treatment approach) did not reduce colitis severity. On the other hand, JOAB-40 administration significantly reduced colitis severity in mice when administered using two approaches; a) prophylactic (given along colitis induction), and b) treatment (given after colitis was established) with doses as low as 10 mg/kg. The degree of inhibition of TNF alpha and IL-1 beta (but not IL-10) release from J774.2 cell line in response to LPS stimulation was more potent with JOAB-40 than E121. This was also observed in vivo in regards to the circulating levels of TNF alpha. Relevant contribution to knowledge: Our results indicate that JOAB-40 is more potent than E121 in reducing colitis severity in mice and may be a promising future therapeutic target for the management of inflammatory bowel disease (IBD).