Effects of Xingnaozaizao capsules on formaldehyde-induced impairment of respiratory system in mice

Objective To observe the effects of Xingnaozaizao capsules on formaldehyde-induced impairment of respiratory system in mice. Methods Kunming mice were randomly divided into 5 groups (n=10): a control group (Group C), a formaldehyde group (Group FA) and a low, middle and high dose of Xingnaozaizao capsule group (Groups XL, XM and XH). From Day 1 to Day 14 of the experiments, all mice except for Group C were exposed to formaldehyde for 2 h every day. Furthermore, Groups XL, XM and XH were orally administrated with Xingnaozaizao capsule suspension at a dose of 1.0, 1.5 and 2.0 g·kg^-1. On Day 14, phenol red excretion test was used to evaluate the excretion function of the bronchi, and the lung coefficient of mice was tested. The contents of malonaldehyde (MDA) and the activities of superoxide dismutase (SOD) and nitricoxide synthase (NOS) in the lung homogenate were measured biochemically. Results Compared with Group C, Group FA demonstrated significantly decreased phenol red excretion (P<0.05), increased MDA contents in the lung homogenate (P<0.05) and reduced activities of SOD and NOS (P<0.01). Compared with Group FA, Group XH demonstrated significantly increased phenol red excretion (P<0.01), reduced MDA contents in the lung homogenate (P<0.01) and increased activities of SOD and NOS (P<0.01), while Group XM presented enhanced NOS activities (P<0.01). Conclusions Xingnaozaizao capsules can improve formaldehyde-induced impairment of respiratory system in mice.