http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : BongJooPark (검색결과 2 건)
- 무료
- 기관 내 무료
- 유료
-
Bong Joo Park,Myung Haing Cho,Kyeong Ho Kim,Sang Kook Lee,Chong Soon Lee,Gil Hwan An,Woong Chon Mar 한국생약학회 1999 Natural Product Sciences Vol.5 No.3
Nitric oxide (NO) is a free radical synthesized from L-arginine by nitric oxide synthase (NOS). It is believed that NO is an important mediator in numerous physiological and inflammatory responses. Particularly, a large amount of NO released from the inducible nitric oxide synthase (iNOS) is mostly associated with inflammatory processes. Overproduction of NO in these processes including sepsis and autoimmune diseases can have deleterious consequences and pathophysiologic relevance. Therefore, for the discovery of new inhibitory agents against iNOS activity, we have evaluated about 100 kinds of natural products after partition into three layers (n-hexane, ethyl acetate and aqueous) from 100% methanol extracts to study inhibitory effects on iNOS activity induced by lipopalysaccharide (LPS) in RAW264.7 cells culture system. As a positive control, curcumin, which is known as an anti-tumor promotor, anti-inflammatory agent as an iNOS inhibitor, was used and showed the dose-dependent inhibitory effect (IC<sub>50</sub>, 2.5 ㎍/㎖). Among tested fractions, the n-hexane fraction of Cimicifuga heracleifolia (IC<sub>50</sub>: 9.65 ㎍/㎖), Forsythiae fructus (IC<sub>50</sub>: 6.36 ㎍/㎖), Saposhnikovia divaricata (IC<sub>50</sub>: 5.92 ㎍/㎖), and the ethyl acetate fraction of Chrysanthemum sibiricum (IC<sub>50</sub>: 2.56 ㎍/㎖), Gastrodia edata (IC<sub>50</sub>: 3.46 ㎍/㎖), and the aqueous fraction of Dianthus chinensis (IC<sub>50</sub>: 6.73 ㎍/㎖), Euonymus alatus (IC<sub>50</sub>: 6.78 ㎍/㎖), Mechania urticifodoria (IC<sub>50</sub>: 8.01 ㎍/㎖) showed strong inhibitory activity against LPSstimulated iNOS. Especially, the ethyl acetate fraction of Chrysanthemum sibiricum (IC<sub>50</sub>: 2.56 ㎍/㎖), which exhibited the strongest inhibition against iNOS, was fractionated with silica-gel column chromatography. These subfracdons exhibited dose-dependent inhibition against iNOS activity in the range of 2.59-5.6 ㎍/㎖ except for fraction No. 3, 4, 5, 6, 8, 9, and 16. Our study shows that Chrysanthemum sibiricum has the strongest inhibitory effect against iNOS activity and has similar effect to curcumin. Therefore, further studies for the identification of active principles from Chrysanthemum sibiricum and investigation for the mechanism of the inhibition of iNOS by active principles will be performed.
-
Direct-Current Treatment as a Safe Sterilization Method for Electrospun Biodegradable Polymer
HyeLeeKim,JeongHyunLee,MiHeeLee,HakHeeKim,JungsungKim,InhoHan,BongJooPark,JeongKooKim,DongWookHan,SooHyunKim,SeungJinLee,JongChulPark 한국조직공학·재생의학회 2011 조직공학과 재생의학 Vol.8 No.3
Sterilization is an essential process for biodegradable polymers to be used as biomaterials or tissue engi-neered-scaffolds. The characteristics of biodegradable scaffolds can change due to decomposition of constituentpolymers due to high temperature, pressure, or moisture during sterilization. This study investigated direct-current (DC) treatment as a safe method that can prevent structural change and deformation. Treatment of electrospun poly (lactic-co-glycolic acid) (PLGA) with DC showed a bactericidal effect within 40 sec at 4 V. When DC was appliedat 6 V to the electrospun PLGA, the bactericidal effect emerged within 30 sec. The morphology of fibers and molec-ular weight of PLGA polymer was maintained after DC treatment. In contrast, electrospun PLGA exposed to ethyl-ene oxide showed fiber degradation, and gamma or e-beam irradiation resulted in decreased molecular weight. Thedemonstrated improvement in chemical and physical stability of biodegradable polymers after DC sterilization mayhelp extend their application.
ScienceON
DBpia연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
