Effects of Chung-Pae Inhalation Therapy on a Mouse Model of Chronic Obstructive Pulmonary Disease

Protective effects of neem (Azadirachta indica A. Juss.) leaf extract against cigarette smoke- and lipopolysaccharide-induced pulmonary inflammation

Neem (Azadirachta indica A. Juss.) leaf has been reported to exert anti-inflammatory, antibacterial and antioxidant effects. The purpose of this study was to investigate the protective effects of neem leaf extract (NLE) against cigarette smoke (CS)- and lipopolysaccharide (LPS)-induced pulmonary inflammation. Treatment with NLE significantly attenuated the infiltration of inflammatory cells, such as neutrophils and macrophages in bronchoalveolar lavage fluid (BALF). NLE also reduced the production of reactive oxygen species and the activity of neutrophil elastase in BALF. Moreover, NLE attenuated the release of pro-inflammatory cytokines, such as tumor necrosis factor-α (TNF-α) and interleukin (IL)-6 in BALF. NLE inhibited the recruitment of inflammatory cells and the expression of monocyte chemoattractant protein-1 (MCP-1) in the lungs of mice with CS- and LPS-induced pulmonary inflammation. NLE also decreased the expression of inducible nitric oxide synthase (iNOS) in the lungs of the mice CS- and LPS-induced pulmonary inflammation. Furthermore, treatment with NLE significantly attenuated the activation of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) in the lungs mice exposed to CS and LPS. NLE also inhibited the phosphorylation of nuclear factor (NF)-κB and inhibitor of NF-κB (IκB) in the lungs of mice expose to CS and LPS. These findings thus suggest that NLE has potential for use in the treatment of chronic obstructive pulmonary disease.

Therapeutic effect of Mahaenggamseok-tang on neutrophilic lung inflammation is associated with NF-κB suppression and Nrf2 activation

ETHNOPHARMACOLOGICAL RELEVANCE

Mahaenggamseok-tang (MHGST), an herbal formula in traditional Asian medicine, has been used to treat patients with various pulmonary diseases including common cold and influenza. However, the potential therapeutic effect of MHGST on acute lung injury (ALI), a leading cause of death worldwide, and the anti-inflammatory mechanisms of MHGST remained less understood.

MATERIALS AND METHODS

The methanol extract of MHGST was prepared and fingerprinted by HPLC. For the induction of ALI, C57BL/6 mice (n=5/group) received a single intraperitoneal (i.p.) injection of LPS. Referring to the dose for patients, two different amounts of MHGST were delivered in an aerosol to mouse lungs via trachea 2h after the i.p. LPS administration. Lung histology, bronchoalveolar lavage fluid, myeloperoxidase (MPO) activity, and the expression of inflammatory and Nrf2-dependent genes were analyzed to determine the effect of MHGST on lung inflammation. For mechanistic studies, western blotting and semi-quantitative RT-PCR were conducted using RAW 264.7 cells.

RESULTS

When administered 2h after the onset of ALI, MHGST relieved lung pathology characteristic to ALI, with decreases of neutrophil infiltration and MPO activity. While suppressing the expression of inflammatory genes, MHGST increased the expression of Nrf2-dependent genes in ALI mouse lungs. Concordantly, MHGST activated Nrf2 activity while suppressing NF-κB in RAW 264.7 cells.

CONCLUSION

MHGST suppressed neutrophilic lung inflammation, a hallmark of ALI, which was associated with the activation of anti-inflammatory Nrf2 and the suppression of pro-inflammatory NF-κB. Our results suggest that MHGST has a therapeutic potential against ALI.

Asiatic acid inhibits pulmonary inflammation induced by cigarette smoke

Asiatic acid (AA) is one of the major components of Titrated extract of Centella asiatica (TECA), which has been reported to possess antioxidant and anti-inflammatory activities. The purpose of this study was to investigate the protective effect of AA on pulmonary inflammation induced by cigarette smoke (CS). AA significantly attenuated the infiltration of inflammatory cells in bronchoalveolar lavage fluid (BALF) of CS exposure mice. AA also decreased ROS production and NE activity, and inhibited the release of proinflammatory cytokines in BALF. AA reduced the recruitment of inflammatory cells and MCP-1 expression in lung tissue of CS exposure mice. AA also attenuated mucus overproduction, and decreased the activation of MAPKs and NF-kB in lung tissue. Furthermore, AA increased HO-1 expression and inhibited the reduced expression of SOD3 in lung tissue. These findings indicate that AA effectively inhibits pulmonary inflammatory response, which is an important process in the development of chronic obstructive pulmonary disease (COPD) via suppression of inflammatory mediators and induction of HO-1. Therefore, we suggest that AA has the potential to treat inflammatory disease such as COPD.