본 연구는 단핵구 또는 대식세포로서 염증과 면역 등에 관여하는 마우스의 RAW 264.7 세포를 이용한 실험모델에서 배미숙과 추출물(IPE)의 항염증 효과를 확인하기 위하여 실시되었다. 세포독성을 나타내지 않는 범위의 농도로 IPE를 투여한 후 LPS를 처리하여 염증반응을 유도하였다. LPS는 대식세포를 자극하여 염증반응을 촉진하는 인자를 생성하였고, IPE 투여 시 MAPKs의 인산화가 억제되어 염증성 사이토카인의 발현과 NO의 생성이 감소하는 신호 전달 경로에 작용하는 것으로 확인되었다. 이는 생체 내외의 다양한 원인에 의해 바람직하지 않게 일어나는 과도한 염증반응을 IPE가 조절하여 정상상태로 회복할 수 있도록 함을 의미한다. 따라서 적과되어 폐기되는 배 미숙과를 이용한 추출물에 새로운 가치를 부여하고 항염증 소재로서 제품화에 활용하는 것은 산업적으로 매우 바람직한 일이 될 것이다.
During the cultivation of pears, the immature pears are thinned out and discarded in large quantities as a by-product. Hence, this study was conducted to find ways to utilize them as a useful resource. The total polyphenol content of the immature pears was about 3.6 times higher than that of mature pears, and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity was about 2 times higher. Specifically, the anti-inflammatory effect of the immature pear extract (IPE) was confirmed in an activated macrophage experimental model. There was no significant change in the cell viability of RAW 264.7 macrophages in the cytotoxicity test wherein IPE was used in the concentration range of 50 to 500 μg/mL. The level of nitric oxide production was significantly reduced along with the decrease in the inducible nitric oxide synthase expression in IPE treated lipopolysaccharides (LPS)-induced inflammation in the macrophages. In addition, the levels of secretion of inflammatory cytokines induced by LPS, such as interleukin (IL)-1β, IL-6, and tumor necrosis factor-α were also reduced. The expression levels of phosphorylated extracellular signal-regulated kinase, phosphorylated Jun N-terminal kinase, and p-p38, which are the major factors inducing inflammation, were reduced. This can be inferred to be the anti-inflammatory effect of IPE caused by a mechanism that inhibits the phosphorylation of factors acting in the mitogen-activated protein kinase (MAPK) pathway. Therefore, IPE could be of commercial value as a new material for use as a healthy functional food and as an anti-inflammatory component for medicinal use.