Callicarpa japonica Thunb. reduces inflammatory responses: A mouse model of lipopolysaccharide-induced acute lung injury

Callicarpa japonica Thunb. (CJT) is traditionally used as an herbal remedy for the treatment of inflammatory diseases. This study aimed to investigate the anti-inflammatory response of CJT in lipopolysaccharide (LPS)-stimulated RAW264.7 cells and LPS-induced acute lung injury (ALI) in mice. The C57BL/6 mice were administered 30mg/kg of CJT by oral gavage for 3days. LPS is applied to animals by intranasal administration 1h after final CJT treatment. LPS is applied to animals by intranasal administration 1h after final CJT treatment. LPS was delivered intranasally 1h after the final CJT treatment. In the LPS-stimulated RAW264.7 cells, CJT significantly decreased nitric oxide (NO) and interleukin (IL)-6 in a concentration-dependent manner by reducing inducible NO synthase (iNOS) and IL-6 mRNA levels. In the ALI model, CJT decreased the inflammatory cell count in the bronchoalveolar lavage fluid (BALF) while IL-6 levels were reduced in CJT-treated mice compared with the ALI control mice. CJT also inhibited airway inflammation by reducing iNOS expression in lung tissue. In conclusion, our results indicate that CJT inhibits inflammatory responses in LPS-stimulated RAW264.7 cells and in the LPS-induced ALI model. Therefore, we suggest that CJT has the potential to treat inflammatory diseases such as pneumonia. •CJT is traditionally used as an herbal remedy for treating inflammatory diseases.•CJT decreased pro-inflammatory mediator in LPS-stimulated RAW264.7 cells.•CJT attenuated inflammation in acute lung injury mouse model.•CJT reduced the expression of IL-6 and iNOS both in vivo and in vitro.•CJT may be a potent therapeutic agent in inflammatory disease.