Therapeutic efficacy of apocynin on acute necrotizing pancreatitis rats

Abstract

Objective To explore the effect and mechanism of NADPH oxidase (NOX) inhibitor apocynin in treating acute necrotizing pancreatitis (ANP) rat. Methods Sixty SD rats were randomly divided into three groups: control group, ANP group and apocynin treated group. ANP rat model was established by retrograde injection of 5% sodium taurocholate into pancreatic duct. ANP rats in apocynin group were treated by intraperitoneal injection of 10 mg·kg-1·d-1 apocynin. Rats in control group underwent sham surgery of opening and closing abdominal cavity. Rats were killed at 12 h and 24 h, respectively. Survival, respiration and renal failure were observed within 24 h. PaO2, amylase and creatinine in arterial blood specimen were detected. Serum TNF-α and IL-6 level was detected by enzyme-linked immunosorbent assay (ELISA). NOX2, p22phox, p67phox and p-NF-κB p65 expression in pancreatic tissue were detected by Western blot. Results In ANP group, the incidence of acute respiratory failure and acute renal failure was 71.42%(5/7) and 100% (7/7)at 24 h, respectively. The incidence of acute respiratory failure and acute renal failure was 22.2%(2/9) and 0(0/9) in apocynin treated group, and the difference was statistically significant (both P<0.01). In Apocynin treated group, PaO2 level was higher than that in ANP group at 24 h [(68.4±6.8) vs (56.5±6.1)mmHg, 1 mmHg=0.133 kPa]. Serum amylase, creatinine, TNF-α and IL-6 level was obviously lower than those in ANP group at 24 h [(2 907±849)vs(6 421±690)U/L, (122.3±19.4)vs(213.0±39.2)μmol/L, (120.0±11.9)vs(302.5±41.6)ng/L, (174.4±19.3)vs(378.6±13.6)ng/L. Pancreatic pathological score was significantly lower than that in ANP group [(3.16±0.91)vs (7.95±1.23); p22phox, p67phox, and p-NF-κB p65 expression in pancreatic tissue was also significantly lower than those in ANP model group[0.79(0.75, 0.84) vs 1.36(1.18, 1.51), 0.82(0.80, 0.87) vs 1.7(1.47, 1.8), 0.82(0.80, 0.84)vs 1.50(1.31, 1.61)]; NOX2 expression was completely inhibited by apocynin[0 vs 0.93(0.87, 1.06)], which were statistically different (all P<0.001). Conclusions Apocynin could exert a therapeutic effect in ANP rats, and the potential mechanism may be associated with NOX mediated activation of NF-κB and TNF-α, IL-6 release. Key words: Pancreatitis, acute necrotizing; NADP oxidase; Apocynin; Treatment outcome