Panax notoginseng attenuates bleomycin-induced pulmonary fibrosis in mice

Panax notoginseng (PN) is a traditional Chinese herb experimentally proven to have anti-inflammatory effects, and it is used clinically for the treatment of atherosclerosis, cerebral infarction, and cerebral ischemia. This study aimed to determine the anti-inflammatory effects of PN against bleomycin-induced pulmonary fibrosis in mice. First, in an in vitro study, culture media containing lipopolysaccharide (LPS) was used to stimulate macrophage cells (RAW 264.7 cell line). TNF-α and IL-6 levels were then determined before and after treatment with PN extract. In an animal model (C57BL/6 mice), a single dose of PN (0.5mg/kg) was administered orally on Day 2 or Day 7 postbleomycin treatment. The results showed that TNF- and IL-6 levels increased in the culture media of LPS-stimulated macrophage cells, and this effect was significantly inhibited in a concentration-dependent manner by PN extract. Histopathologic examination revealed that PN administered on Day 7 postbleomycin treatment significantly decreased inflammatory cell infiltrates, fibrosis scores, and TNF-α , TGF-β, IL-1β , and IL-6 levels in bronchoalveolar lavage fluid when compared with PN given on Day 2 postbleomycin treatment. These results suggest that PN administered in the early fibrotic stage can attenuate pulmonary fibrosis in an animal model of idiopathic pulmonary fibrosis.