Anti-inflammatory effect of SQC-β-CD on lipopolysaccharide-induced acute lung injury

Aim of the studyShuang-Qing-Cao (SQC) is a folk Chinese medicinal formula. The therapeutic effects of inclusion complexation of SQC extract in β-cyclodextrin (SQC-β-CD) against lipopolysaccharide (LPS)-induced acute lung injury (ALI) were studied in mice.Materials and MethodsTwo protocols were designed for administration of SQC-β-CD (10 and 20 mg/kg body weight) or DEX (2 mg/kg). According to Protocol A we intraperitoneally injected diluent (saline with 0.5% Tween 80), SQC-β-CD or DEX respectively into mice 30 min and 3 h after LPS challenge. Alternatively, in Protocol B we administered diluent, SQC-β-CD or DEX 3 h before and 30 min after LPS challenge.ResultsThe histological results showed that SQC-β-CD (20 mg/kg) protected mice from LPS-induced ALI such as oedema, haemorrhage, blood vessel and alveolar structural damage. Furthermore, SQC-β-CD inhibited LPS-increased pulmonary MPO activity and migration of polymorphonuclear neutrophils (PMNs) into bronchoalveolar lavage fluid (BALF). Immunohistochemical experiment demonstrated that SQC-β-CD decreased inducible nitric oxide synthase (iNOS) expression in lung 24 h after LPS administration. Consequently, SQC-β-CD prevented LPS-induced nitric oxide (NO) release in BALF.ConclusionsThe results indicated that SQC-β-CD is greatly effective in inhibiting ALI. The present study indicated that SQC-β-CD acted as a potential therapeutic reagent for treating ALI.