BTZO 1 binds to migration inhibitory factor (MIF) with a Kd of 68.6 nM [1].

MIF is a ubiquitous protein. It is a specific BTZO 1-binding protein. MIF is released by ischemic heart tissue. It activates the cardioprotective AMP-activated protein kinase (AMPK) pathway. MIF was reported to be a key upstream regulator of the innate and acquired immune response. MIF regulates cytokine secretion, counter-regulates glucocorticoids in inflammation, inhibits oxidative stress-induced cell death, and activates components of the Jun-activation domain-binding protein-1 (Jab-1) pathway and mitogen-activated protein kinase [1].

H9c2 cells transfected by pGL3-ARE-Luc were treated with rMIF in the presence of BTZO 1 at 1 μM. In this system, dose-dependently induced luciferase activity was found. When transfected cells were treated with rMIF alone, ARE-mediated luciferase activity was scarcely induced. Treatment with BTZO 1, also promoted rMIF induction of HO-1 mRNA and GST Ya in H9c2 cells. In H9c2 cells, pretreatment with BTZO 1 at 30 μM caused an approximately 20% decrease in tautomerase activity (measured in the cell lysate). This suggested that there was a direct interaction between MIF and BTZO 1 in H9c2 cells [1].

BTZO 2 is a BTZO 1 analog with a better ADME profile. 24 hr after reperfusion with drug, mean values for the area at risk were 46% ± 3% and 48% ± 2% for vehicle and BTZO 2, respectively. In control rats, left anterior descending coronary artery (LAD) occlusion and reperfusion caused an infarct size of 43% of the area at risk. Compared to control, intraperitoneal administration with BTZO 2 at 10 mg/kg 1 hr prior to LAD occlusion and 2 and 8 hr after reperfusion caused an approximately 45% reduction in the infarct size [1].

Reference:
[1].  Kimura H, Sato Y, Tajima Y, et al. BTZO-1, a cardioprotective agent, reveals that macrophage migration inhibitory factor regulates ARE-mediated gene expression. Chemistry & biology, 2010, 17(12): 1282-1294.