Inflammatory mediator regulation of the Zizyphus jujube leaf fractions in the LPS-stimulated Raw264.7 mouse machrophage

Zizyphus jujube leaf fractions (ZLFs) showed no cytotoxic effects of up to $100{\mu}g/mL$, while the anti-inflammatory effects of ZLFs were analyzed by checking the productions of nitric oxide (NO), prostaglandin $E_2$ ($PGE_2$), cyclooxygenase-2 (COX-2), and inflammatory cytokines TNF-${\alpha}$, IL-$1{\beta}$, and IL-6 in the lipopolysaccharide (LPS)-stimulated Raw264.7 macrophage up to the concentration of $100{\mu}g/mL$. ZLFs ($100{\mu}g/mL$) demonstrated a strong anti-inflammatory activity that reduced 61~85% of NO and 71~100% of $PGE_2$ production in the LPS-stimulated Raw264.7 macrophage. Even the low ZLFs concentration of $1{\mu}g/mL$ have reduced NO and $PGE_2$ production by 34~64%. Expressions of COX-2 protein were also effectively inhibited by the ZLFs. Furthermore, the TNF-${\alpha}$, IL-$1{\beta}$, and IL-6 production were significantly suppressed through the treatment of ZLFs at concentrations of 1, 10, and $100{\mu}g/mL$. In the order of the Zizyphus jujube leaf water fraction (ZLWF) < buthanol fraction (ZLBF) < ethyl acetate fraction (ZLEF) showed anti-inflammatory activity. In particular, the ethyl acetate fraction ZLEF at $100{\mu}g/mL$ showed an excellent anti-inflammatory activity by reducing the production of NO, $PGE_2$, COX-2, and inflammatory cytokines (TNF-${\alpha}$, IL-$1{\beta}$, IL-6) in the level of Raw264.7 macrophage without LPS-stimulation or even better. The results of our study suggest the potential of ZLEF for use as an excellent ant-inflammatory inhibiting mediator and may be used as a therapeutic approach to various inflammatory diseases.

LPS로 염증이 유도된 Raw 264.7 대식세포에서 대추(Zizyphus jujube) 잎 분획물의 염증매개물질 억제

LPS로 염증이 유도된 Raw264.7 macrophage에서 대추잎 분획물(Zizyphus jujuba leaf fractions; ZLFs)의 항염증 효과를 살펴 보기위해 세포독성이 나타나지 않은 1, 10, $100{\mu}g/mL$ 농도 범위에서 염증매개물질인 NO, $PGE_2$, 염증성 cytokine(TNF-${\alpha}$, IL-$1{\beta}$ 및 IL-6) 생성 및 COX-2 단백질의 발현을 측정하였다. 그 결과, ZLFs(ZLWF, ZLEF, ZLBF)는 처리 농도 범위에서 효과적으로 NO, $PGE_2$, 염증성 cytokine 생성 및 COX-2 단백질 발현을 억제하였다. 분획 용매에 따른 효과를 살펴보면 ZLWF< ZLBF< ZLEF의 순으로 높은 효과를 나타냈고, 특히 에틸 아세테이트 분획물 ZLEF은 $100{\mu}g/mL$ 처리 농도에서 NO, $PGE_2$, 염증성 cytokine 생성 및 COX-2 단백질 발현 억제 효과가 LPS를 처리하지 않은 음성 대조군보다 우수하거나 비슷하여 본 연구에서 조사된 대추 잎 분획물 중 가장 뛰어난 염증 억제제 후보물질로 확인되었다.