Abstract

 Objective: This study investigated the frequency of apoptosis in rat pulmonary epithelial cells after the injection of an intraperitoneal endotoxin lipopolysaccharide (LPS), the effects of LPS on apoptotic (bax, caspase-3) and antiapoptotic (bcl-2) markers during lung damage, and the protective effects of two known antioxidant agents, erdosteine and N-acetylcysteine (NAC).

Materials and Methods: Male Wistar rats were divided into the following six groups, which included nine rats each: two control groups, two LPS-treated groups, one erdosteine-treated group (150 mg/kg), and one NAC-treated group (150 mg/kg). LPS was injected intraperitoneally at a dosage of 20 mg/kg. Following LPS injection, the antioxidants were orally administered. The rats were sacrificed at 24 h after LPS administration. The levels of apoptosis in bronchiolar and alveolar cells were determined using the TUNEL-staining method. Immunohistochemical staining of cytoplasmic bax, caspase-3, and bcl-2 in the epithelial cells was performed.

Results: Erdosteine and NAC significantly reduced the rate of LPS-induced pulmonary epithelial cell apoptosis. The effect of NAC on regulating apoptosis was weaker than that of erdosteine. Erdosteine and NAC significantly reduced the local induction of bax and caspase 3 and significantly increased the reduced local production of bcl-2.

Conclusion: These findings suggest that erdosteine and NΑC can effectively protect the lungs from the damaging effects of LPS.