PCL-2

PCL-2 is a fluorescent probe responsive to reactive oxygen species, specifically reacting with hydrogen peroxide while showing minimal response to other biologically relevant reactive oxygen species. Upon reacting with hydrogen peroxide, PCL-2 releases 6-hydroxy-2-cyanobenzothiazole. This compound is suitable for chemically selective imaging of hydrogen peroxide both in vitro and in acute inflammation mouse models. PCL-2 is applicable in studies related to acute inflammation.

PCL-2 (5 μM; 5, 20, 40, or 60 min) enhances luminescence signals triggered by H₂O₂ approximately 50-fold in a cell-free system, without affecting other biologically relevant ROS. In a cell-free setup, PCL-2 (5 μM; 60 min) produces a linear increase in luminescent signal across 1-100 μM H₂O₂. PCL-2 (25 μM; 2 h) induces a statistically significant and linear increase in luminescence in PC3M-luc cells with 0-100 μM H₂O₂.

PCL-2 (0.05 μmol; intraperitoneal injection) is capable of responding to exogenous hydrogen peroxide in healthy FVB-luc+ mice, generating a bioluminescent signal that increases in a dose-dependent manner, up to 10-fold, and can be inhibited by hydrogen peroxide scavengers. PCL-2 (0.05 μmol; intraperitoneal injection) detects a 3.7-fold increase in endogenous hydrogen peroxide (H2O2) levels during lipopolysaccharide-induced acute inflammation in female FVB-luc+ mice, with a 55% signal reduction following apocynin treatment. When used in combination with IETDC, PCL-2 (0.05 μmol; intraperitoneal injection) detects a simultaneous 2.7-fold increase in endogenous hydrogen peroxide and caspase 8 activity during lipopolysaccharide-induced acute inflammation in female FVB-luc+ mice; this signal is reduced by 30% when treated with ascorbic acid and a caspase inhibitor.