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