Enhancement of the Anti-inflammatory Activities of Aralia continentalis Kitagawa Extracts Fermented by Lactobacillus plantarum

추출용액에 따른 유산균 발효 땅두릅의 항염증 효과

Abstract

We investigated the anti-inflammatory activities of various organic solvent extracts with and without Lactobacillus plantarum fermentation of Aralia continentalis Kitagawa which has hypotensive effects in addition to excitatory effects on the central nervous system. It has been used to treat arthritis, colds, neuralgia, rheumatism, and itchy skin. Our extracts were tested for their anti-inflammatory potential on NO production and the expression of inflammatory factors in lipopolysaccharide-stimulated RAW264.7 macrophages. Extracts with and without L. plantarum fermentation were prepared using water, ethanol, hexane, ethyl acetate, and butanol. The RAW264.7 cells were tested for toxicity and the anti-inflammatory activity of each extract was determined at a concentration with no toxicity to the cells. The extracts used in this study significantly inhibited both the production of NO and the mRNA expression of COX-2 and iNOS, the major inflammatory factors. The production of inflammation-related cytokines $IL-1{\beta}$, IL-6, and $TNF-{\alpha}$ was also significantly reduced. These results suggest that the extracts involving fermentation by L. plantarum can inhibit cytokines by controlling the expression of inflammatory cytokine genes. It is considered that the water, ethanol, and butanol extracts after fermentation with L. plantarum could be useful as functional natural materials with anti-inflammatory effects.

본 연구는 추출 용매별 땅두릅 추출물과 Lactobacillus plantarum으로 발효한 후 용매별로 추출한 땅두릅 발효추출물을 이용하여 항염증 효과를 측정한 연구이다. 땅두릅은 중추신경 계통에 대한 흥분작용이 있고 혈압강하 작용이 알려져 있으며 관절염, 감기, 신경통, 류마티스, 피부가려움증 등에 쓰인다. LPS (lipopolysaccharide)로 염증을 유도한 마우스 유래 macrophage에서의 NO 생성 및 염증관련인자의 발현에 미치는 영향을 검토하여 항염증 소재로서의 이용 가능성을 확인하였다. 건조 땅두릅을 water, ethanol, hexane, ethyl acetate, butanol을 이용하여 추출한 추출물들과 L. plantarum으로 발효한 후 추출한 추출물들에서 RAW264.7 대식세포에 대한 독성 여부를 측정하였고, 세포에 대한 독성이 나타나지 않는 농도에서 추출물의 항염증 활성을 확인하였다. 본 실험에 사용된 추출물은 LPS로 유도된 NO 생성을 유의적으로 억제하였으며, 주요 염증 유발인자인 COX-2와 iNOS의 발현 또한 유의적으로 억제하는 효과를 나타냈다. 염증관련 cytokine인 $IL-1{\beta}$, IL-6 및 $TNF-{\alpha}$의 생성량 또한 유의적으로 감소시켰다. 이상의 결과로부터 땅두릅을 L. plantarum으로 발효한 후 water, ethanol, butanol로 추출하였을 때 염증 억제 효과가 있는 기능성 식품 소재로서의 개발 가능성이 있을 것으로 사료된다.

Fig. 1. Effect of various extracts from A. continentalis Kitagawa on the viability of the RAW264.7 cells by the CCK assay.

Fig. 2. Effect of various extracts from A. continentalis Kitagawa on LPS-induced nitrite production in RAW264.7 cells.

Fig. 3. Effect of various extracts from A. continentalis Kitagawa on COX-2 and iNOS gene expression in the LPS-induced RAW264.7 cells.

Fig. 4. Effect of various extracts from A. continentalis Kitagawa on the production and gene expression of inflammatory cytokines in the LPS-induced RAW264.7 cells.

Table 1. Primers for RT-PCR analysis

Table 2. Effect of various extracts from A. continentalis Kitagawa on DPPH radical scavenging activity