Coptis japonica (C. japonica) is a perennial medicinal plant that has anti-inflammatory activity. C. japonica contains numerous biologically active alkaloids including berberine, palmatine, epi-berberine, and coptisine. The most well-known anti-inflammatory principal in C. japonica is berberine. For example, berberine has been implicated in the inhibition of iNOS induction by cytokines in microglial cells. However, the efficacies of other alkaloids components on microglial activation were not investigated yet. In this study, we investigated the effects of three alkaloids (palmatine, epi-berberine and coptisine) from C. japonica on lipopolysaccharide (LPS)-induced microglial activation. BV2 microglial cells were immunostimulated with LPS and then the production of several inflammatory mediators such as nitric oxide (NO), reactive oxygen species (ROS) and matrix metalloproteinase-9 (MMP-9) were examined as well as the phosphorylation status of Erk1/2 mitogen activated protein kinase (MAPK). Palmatine and to a lesser extent epi-berberine and coptisine, significantly reduced the release of NO, which was mediated by the inhibition of LPS-stimulated mRNA and protein induction of inducible nitric oxide synthase (iNOS) from BV2 microglia. In addition to NO, palmatine inhibited MMP-9 enzymatic activity and mRNA induction by LPS. Palmatine also inhibited the increase in the LPS-induced MMP-9 promoter activity determined by MMP-9 promoter luciferase reporter assay. LPS stimulation increased Erk1/2 phosphorylation in BV2 cells and these alkaloids inhibited the LPS-induced phosphorylation of Erk1/2. The anti-inflammatory effect of palmatine in LPS-stimulated microglia may suggest the potential use of the alkaloids in the modulation of neuroinflammatory responses, which might be important in the pathophysiological events of several neurological diseases including Alzheimer's disease (AD), multiple sclerosis (MS), Parkinson's disease (PD) and stroke.
Lee, Hyun Ah;Kim, Ji Eun;Choi, Jun Young;Sung, Ji Eun;Youn, Woo Bin;Son, Hong Joo;Lee, Hee Seob;Kang, Hyun-Gu;Hwang, Dae Youn
Journal of Life Science
/
v.30
no.4
/
pp.331-342
/
2020
The suppression of neuroinflammatory responses in microglial cells can be considered a key target for improving the progression of neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD). Asparagus cochinchinensis has traditionally been used as a medicine to treat fever, cough, kidney disease, breast cancer, inflammatory diseases, and brain diseases. In this study, we investigated the neuroprotective mechanism of an aqueous extract from A. cochinchinensis root (AEAC), particularly its anti-inflammatory effects on lipopolysaccharide (LPS)-activated BV-2 microglial cells. BV-2 cells were treated with four different concentrations of AEAC. No significant toxicity was detected in BV-2 cells treated with AEAC. Nitric oxide (NO), cyclooxygenase-2 (COX-2) mRNA, and inducible nitric oxide synthase (iNOS) mRNA levels were 21% lower in the AEAC+LPS group than in the Vehicle+LPS group. Lower proinflammatory (TNF-α and IL-1β) and anti-inflammatory cytokine (IL-6 and IL-10) levels were also detected in the AEAC+LPS group than in the Vehicle+LPS group, albeit at varying rates. Moreover, the phosphorylation of mitogen-activated protein kinase (MAPK) members after LPS treatment was significantly recovered in the AEAC-pretreated group compared to the Vehicle+LPS group, enhancement of the phosphorylation of mitogen-activated protein kinase (MAPK) members after LPS treatment was significantly recovered in the AEAC-pretreated group, while cell cycle arrest at the G2/M phase caused by LPS treatment was less severe in the AEAC+LPS group. The increase in reactive oxygen species (ROS) generation induced by LPS treatment was also lower in the AEAC-pretreated group than in the Vehicle+LPS group. This is the first study to show that AEAC exerts anti-neuroinflammatory activity against LPS stimulation by regulating the MAPK signaling pathway, the cell cycle, and ROS production.
The objective of the present study was to determine the expression of genes associated with lipopolysaccharide (LPS)-induced stressor in two breeds of chickens: the Korean native chicken (KNC) and the White Leghorn chicken (WLH). Forty chickens per breed, aged 40 weeks, were randomly allotted to the control (CON, administered the saline vehicle) and LPS-injected stress groups. Samples were collected at 0 and 48 h post-LPS injection, and total RNA was extracted from the chicken livers for RNA microarray and quantitative real-time polymerase chain reaction (qRT-PCR) analyses. In response to LPS, 1,044 and 1,193 genes were upregulated, and 1,000 and 1,072 genes were downregulated in the KNC and WLH, respectively, using a ${\geq}2$-fold cutoff change. A functional network analysis revealed that stress-related genes were downregulated in both KNC and WLH after LPS infection. The results obtained from the qRT-PCR analysis of mRNA expression of heat shock 90 (HSP90), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), activating transcription factor 4 (ATF4), sterol regulatory element-binding protein 1 (SREBP1), and X-box binding protein 1 (XBP1) were confirmed by the results of the microarray analysis. There was a significant difference in the expression of stress-associated genes between the control and LPS-injected KNC and WLH groups. The qRT-PCR analysis revealed that the stress-related $HSP90{\alpha}$ and HMGCR genes were downregulated in both LPS-injected KNC and WLH groups. However, the HSP70 and $HSP90{\beta}$ genes were upregulated only in the LPS-injected KNC group. The results suggest that the mRNA expression of stress-related genes is differentially affected by LPS stimulation, and some of the responses varied with the chicken breed. A better understanding of the LPS-induced infective stressors in chicken using the qRT-PCR and RNA microarray analyses may contribute to improving animal welfare and husbandry practices.
It was found that the peptides originated from the hydrolysates of silk fibroin have in vitro immunostimulating effects in murine macrophage RAW264.7 cells. The stimulation effects on nitric oxide (NO) production resulted from treatments of acid or enzymatic hydrolysates were measured. The silk fibroin preparation isolated from cocoon was most efficiently digested by acid hydrolysis. Even though the sole treatment of acid hydrolysate stimulated the NO production in dose-dependent pattern, a part of its activity was found to be caused by the contaminated endotoxin, LPS. When each endotoxin-free hydrolysates obtained by filtering it through an ultrafiltration membrane of molecular weight (MW) cut-off 10,000 to eliminate LPS was used, the peptic hydrolysate with lowest degree of hydrolysis showed the highest activity. The fractions of peptic hydrolysate with MW ranges of 1,000∼10,000, 500∼1,000 and below 500 also showed a higher MW-higher activity correlation. From the analyses of amino acid composition of each hydrolysate, it was found that the contents of arginine, lysine, alanine and glycine residues affected the activity level of hydrolysate. The results of this study showed a possibility of utilizing fibroin as a source for immunostimulating (chemopreventive) functional peptides.
Aberrant activation of microglia has been reported to cause neuronal damages by releasing a variety of pro-inflammatory cytokines. Besides where microglia become active, damages have been also observed in remote places, which is considered due to the migration of activated microglia. Therefore, an agent that could suppress abnormal activation of microglia and their subsequent migration might be valuable in activated microglia-related brain pathologies. The objective of the present study was to evaluate anti-inflammatory effects of betulinic acid on lipopolysaccharide (LPS)-stimulated BV2 microglial cells. Pretreatment of betulinic acid significantly attenuated LPS-induced NO production and protein expression of iNOS. Betulinic acid also significantly suppressed LPS-induced release and expression of cytokines such as TNF-${\alpha}$ and IL-$1{\beta}$. Furthermore, betulinic acid significantly uppressed LPS-induced MMP-9 expression, which has been suggested to play an important role in the migration of activated microglia. In order to understand the possible mechanism by which betulinic acid suppresses LPS-induced cytokine production and migration of microglia, the role of NF-kB, a major pro-inflammatory transcription factor, was examined. Betulinic acid significantly suppressed LPS-induced degradation of IKB, which retains NF-kB in the cytoplasm. Therefore, nuclear translocation of NF-kB upon LPS stimulation was significantly suppressed with betulinic acid. Taken together, the present study for the first time demonstrates that betulinic acid possesses anti-inflammatory activity through the suppression of nuclear translocation of NF-kB in BV2 microglial cells.
Objectives : Noemyeong-san (NMS) is a novel herbal prescription composed of five oriental medicinal herbs including Prunellae Spica, Betulae Cortex, Foeniculi Fructus, Asiasari Radix, and Clematidis Radix for treating Alzheimer's disease. In the present study, we investigated the effects and molecular mechanisms of NMS on BV2 microglia to evaluate the potential action of this formula for preventing or treating neurodegenerative disease such as Alzheimer's disease. Methods : To determine the cytotoxicity of NMS on BV2 microglia, the MTT assay was performed. The effects of NMS on lipopolysaccharide (LPS)-stimulated BV2 microglia were determined with a nitric oxide (NO) assay and western blots for inflammatory mediator-related proteins, mitogen activated protein kinases (MAPKs), nuclear factor kappa B (NF-${\kappa}B$) pathway-related proteins, and heme oxygenase-1 (HO-1). Result : NMS inhibited induction of iNOS and COX-2 as well as NO production without affecting the cell viability in LPS-stimulated BV2 microglia. NMS also suppressed activation of ERK and p38 MAPK among main kinases of MAPKs as well as NF-${\kappa}B$ by LPS stimulation. Furthermore, NMS dose-dependently induced the expression of HO-1 and the inhibitory effect of NMS on the production of NO were blocked by pretreatment with an HO-1 inhibitor, Snpp. Conclusions : These results demonstrate that NMS has potent anti-neuroinflammatory effect on the LPS-stimulated microglia. These findings provide evidences for NMS to be considered as a new prescription for preventing or treating neurodegenerative disease such as Alzheimer's disease.
Jang Seon-Il;Kim Hyung-Jin;Kim Young-Jun;Pae Hyun-Ock;Chung Hun-Taeg;Yun Yong-Gab;Jeong Ok-Sam;Kim Youn-Chul
Herbal Formula Science
/
v.11
no.1
/
pp.115-128
/
2003
Bojungikgitang is the water extracts prepared from Ginseng Radix, Astragali Radix, Angelicae gigantis Radix, Astractylodis Rhizoma alba, Aurantii nobilis Pericarpium, Glycyrrhizae Radix, Bupleuri Radix, Cimicifugae Rhizoma, which has been used for the treatment of indigestion, and immunological disease in oriental countries. In this study, the effects of Bojungikgitang on the productions of nitiric oxide (NO) and prostaglandin $E_2\;(PGE_2)$, and the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were examined using RAW 264.7 macrophages activated with $interferon-{\gamma}\;(IFN-{\gamma})$ plus lipopolysaccharide (LPS). Bojungikgitang (10-400 ${\mu}$g/ml) per se had no cytotoxic effect in unstimulated macrophages, but this compound dose-dependently reduced the release of NO and $PGE_2$ caused by stimulation of $LPS/IFN-{\gamma}$. The levels of iNOS and COX-2 protein were markedly suppressed by the treatment with Bojungikgitang in a concentration dependent manner. Moreover, Bojungikgitang also attenuated the production of tumor necrosis factor (TNF)-${\alpha}$, interleukin (1L)-1${\beta}$ and IL-6 in LPS-stimulated RAW 264.7 macrophages. These results suggest that Bojungikgitang decreases the NO and $PGE_2$ production in macrophages by inhibiting iNOS and COX-2 expression and these properties may contribute to the anti-inflammatory activity of Bojungikgitang.
Ma, Ying Jie;Kang, Hee Jung;Kim, Ji Yeon;Garred, Peter;Lee, Myung-Shik;Lee, Bok Luel
BMB Reports
/
v.46
no.7
/
pp.376-381
/
2013
It is unknown how soluble pattern-recognition receptors in blood, such as mannose-binding lectin (MBL) and ficolins, modulate mast cell-mediated inflammatory responses. We investigate how mouse MBL-A or ficolin-A regulate mouse bone marrow-derived mast cells (mBMMCs)-derived inflammatory response against bacterial lipopolysaccharide (LPS) stimulation. LPS-mediated pro-inflammatory cytokine productions on mBMMCs obtained from Toll-like receptor4 (TLR4)-deficient mice, TLR2-defficient mice, and their wildtype, were specifically attenuated by the addition of either mouse MBL-A or ficolin-A in a dose-dependent manner. However, the inhibitory effects by mouse MBL-A or ficolin-A were restored by the addition of mannose or N-acetylglucosamine, respectively. These results suggest that mouse MBL-A and ficolin-A bind to LPS via its carbohydrate-recognition domain and fibrinogen-like domain, respectively, whereby cytokine production by LPS-mediated TLR4 in mBMMCs appears to be down-regulated, indicating that mouse MBL and ficolin may have an inhibitory function toward mouse TLR4-mediated excessive inflammation on the mast cells.
Although nuclear factor of activated T cell (NFAT) plays a key role in inflammation, its anti-inflammatory effects and mechanism of action in periodontitis are still unknown. This study aimed to identify the effects of NFAT on the proinflammatory mediators activated by lipopolysaccharide (LPS) plus nicotine stimulation in human periodontal ligament cells (hPDLCs). The production of nitric oxide (NO) and prostaglandin $E_2(PGE_2)$ was evaluated using Griess reagent and an enzyme immunoassay, respectively. The expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and NFAT proteins was evaluated by Western blot analysis. LPS plus nicotine synergistically induced the production of NO and $PGE_2$ and increased the protein expression of iNOS, COX-2 and NFAT. Treatment with an NFAT inhibitor blocked the LPS plus nicotine-stimulated NO and $PGE_2$ release as well as the expression of iNOS and COX-2. Our data suggest that the LPS plus nicotine-induced inflammatory effects on hPDLCs may act through a novel mechanism involving the action of NFAT. Thus, NFAT may provide a potential therapeutic target for the treatment of periodontal disease associated with smoking and dental plaque.
Objectives : Hedgehog skin is one of the animal medicines in Traditional Korean Medicine for hematochezia and hemorrhoids. In this study, we examined cytotoxicity and anti-inflammatory effects. Methods : Cytotoxicity of hedgehog skin extracts was measured by MTT assay in vitro. We investigated the inhibition of lipopolysaccharide (LPS) stimulated nitric oxide (NO) production in RAW 264.7 cells. The phosphorylation of mitogen-activated protein kinases (MAPKs) was measured by western blot. And we observed the effect of hedgehog skin extracts on the expression of IL-6 genes using real time PCR. Results : As a result of MTT assay for cytotoxicity, there were no significant differences between non-treatment group and hedgehog skin extracts treatment groups. $500{\mu}g/m{\ell}$ of hedgehog skin extracts treatment significantly decreased nitric oxide production in comparison with non-treatment in LPS-induced RAW 264.7 cells. In measurement of the phosphorylation of MAPKs using western blot analysis, LPS stimulation increased the phosphorylation of MAPKs and $500{\mu}g/m{\ell}$ of hedgehog skin extracts treatment decreased the phosphorylation of ERK1, ERK2 and p38 significantly. But there were no significant differences the phosphorylation of JNK1 and JNK2. As a result of confirmation of the IL-6 mRNA gene expression using real time PCR, IL-6 mRNA gene expressions were significantly decreased in $50{\mu}g/m{\ell}$, $100{\mu}g/m{\ell}$ and $500{\mu}g/m{\ell}$ hedgehog skin extracts treated groups by comparison with non-treatment group. Conclusion : These results could provide a mechanistic explanation for the anti-inflammatory effects of the hedgehog skin.
본 웹사이트에 게시된 이메일 주소가 전자우편 수집 프로그램이나
그 밖의 기술적 장치를 이용하여 무단으로 수집되는 것을 거부하며,
이를 위반시 정보통신망법에 의해 형사 처벌됨을 유념하시기 바랍니다.
[게시일 2004년 10월 1일]
이용약관
제 1 장 총칙
제 1 조 (목적)
이 이용약관은 KoreaScience 홈페이지(이하 “당 사이트”)에서 제공하는 인터넷 서비스(이하 '서비스')의 가입조건 및 이용에 관한 제반 사항과 기타 필요한 사항을 구체적으로 규정함을 목적으로 합니다.
제 2 조 (용어의 정의)
① "이용자"라 함은 당 사이트에 접속하여 이 약관에 따라 당 사이트가 제공하는 서비스를 받는 회원 및 비회원을
말합니다.
② "회원"이라 함은 서비스를 이용하기 위하여 당 사이트에 개인정보를 제공하여 아이디(ID)와 비밀번호를 부여
받은 자를 말합니다.
③ "회원 아이디(ID)"라 함은 회원의 식별 및 서비스 이용을 위하여 자신이 선정한 문자 및 숫자의 조합을
말합니다.
④ "비밀번호(패스워드)"라 함은 회원이 자신의 비밀보호를 위하여 선정한 문자 및 숫자의 조합을 말합니다.
제 3 조 (이용약관의 효력 및 변경)
① 이 약관은 당 사이트에 게시하거나 기타의 방법으로 회원에게 공지함으로써 효력이 발생합니다.
② 당 사이트는 이 약관을 개정할 경우에 적용일자 및 개정사유를 명시하여 현행 약관과 함께 당 사이트의
초기화면에 그 적용일자 7일 이전부터 적용일자 전일까지 공지합니다. 다만, 회원에게 불리하게 약관내용을
변경하는 경우에는 최소한 30일 이상의 사전 유예기간을 두고 공지합니다. 이 경우 당 사이트는 개정 전
내용과 개정 후 내용을 명확하게 비교하여 이용자가 알기 쉽도록 표시합니다.
제 4 조(약관 외 준칙)
① 이 약관은 당 사이트가 제공하는 서비스에 관한 이용안내와 함께 적용됩니다.
② 이 약관에 명시되지 아니한 사항은 관계법령의 규정이 적용됩니다.
제 2 장 이용계약의 체결
제 5 조 (이용계약의 성립 등)
① 이용계약은 이용고객이 당 사이트가 정한 약관에 「동의합니다」를 선택하고, 당 사이트가 정한
온라인신청양식을 작성하여 서비스 이용을 신청한 후, 당 사이트가 이를 승낙함으로써 성립합니다.
② 제1항의 승낙은 당 사이트가 제공하는 과학기술정보검색, 맞춤정보, 서지정보 등 다른 서비스의 이용승낙을
포함합니다.
제 6 조 (회원가입)
서비스를 이용하고자 하는 고객은 당 사이트에서 정한 회원가입양식에 개인정보를 기재하여 가입을 하여야 합니다.
제 7 조 (개인정보의 보호 및 사용)
당 사이트는 관계법령이 정하는 바에 따라 회원 등록정보를 포함한 회원의 개인정보를 보호하기 위해 노력합니다. 회원 개인정보의 보호 및 사용에 대해서는 관련법령 및 당 사이트의 개인정보 보호정책이 적용됩니다.
제 8 조 (이용 신청의 승낙과 제한)
① 당 사이트는 제6조의 규정에 의한 이용신청고객에 대하여 서비스 이용을 승낙합니다.
② 당 사이트는 아래사항에 해당하는 경우에 대해서 승낙하지 아니 합니다.
- 이용계약 신청서의 내용을 허위로 기재한 경우
- 기타 규정한 제반사항을 위반하며 신청하는 경우
제 9 조 (회원 ID 부여 및 변경 등)
① 당 사이트는 이용고객에 대하여 약관에 정하는 바에 따라 자신이 선정한 회원 ID를 부여합니다.
② 회원 ID는 원칙적으로 변경이 불가하며 부득이한 사유로 인하여 변경 하고자 하는 경우에는 해당 ID를
해지하고 재가입해야 합니다.
③ 기타 회원 개인정보 관리 및 변경 등에 관한 사항은 서비스별 안내에 정하는 바에 의합니다.
제 3 장 계약 당사자의 의무
제 10 조 (KISTI의 의무)
① 당 사이트는 이용고객이 희망한 서비스 제공 개시일에 특별한 사정이 없는 한 서비스를 이용할 수 있도록
하여야 합니다.
② 당 사이트는 개인정보 보호를 위해 보안시스템을 구축하며 개인정보 보호정책을 공시하고 준수합니다.
③ 당 사이트는 회원으로부터 제기되는 의견이나 불만이 정당하다고 객관적으로 인정될 경우에는 적절한 절차를
거쳐 즉시 처리하여야 합니다. 다만, 즉시 처리가 곤란한 경우는 회원에게 그 사유와 처리일정을 통보하여야
합니다.
제 11 조 (회원의 의무)
① 이용자는 회원가입 신청 또는 회원정보 변경 시 실명으로 모든 사항을 사실에 근거하여 작성하여야 하며,
허위 또는 타인의 정보를 등록할 경우 일체의 권리를 주장할 수 없습니다.
② 당 사이트가 관계법령 및 개인정보 보호정책에 의거하여 그 책임을 지는 경우를 제외하고 회원에게 부여된
ID의 비밀번호 관리소홀, 부정사용에 의하여 발생하는 모든 결과에 대한 책임은 회원에게 있습니다.
③ 회원은 당 사이트 및 제 3자의 지적 재산권을 침해해서는 안 됩니다.
제 4 장 서비스의 이용
제 12 조 (서비스 이용 시간)
① 서비스 이용은 당 사이트의 업무상 또는 기술상 특별한 지장이 없는 한 연중무휴, 1일 24시간 운영을
원칙으로 합니다. 단, 당 사이트는 시스템 정기점검, 증설 및 교체를 위해 당 사이트가 정한 날이나 시간에
서비스를 일시 중단할 수 있으며, 예정되어 있는 작업으로 인한 서비스 일시중단은 당 사이트 홈페이지를
통해 사전에 공지합니다.
② 당 사이트는 서비스를 특정범위로 분할하여 각 범위별로 이용가능시간을 별도로 지정할 수 있습니다. 다만
이 경우 그 내용을 공지합니다.
제 13 조 (홈페이지 저작권)
① NDSL에서 제공하는 모든 저작물의 저작권은 원저작자에게 있으며, KISTI는 복제/배포/전송권을 확보하고
있습니다.
② NDSL에서 제공하는 콘텐츠를 상업적 및 기타 영리목적으로 복제/배포/전송할 경우 사전에 KISTI의 허락을
받아야 합니다.
③ NDSL에서 제공하는 콘텐츠를 보도, 비평, 교육, 연구 등을 위하여 정당한 범위 안에서 공정한 관행에
합치되게 인용할 수 있습니다.
④ NDSL에서 제공하는 콘텐츠를 무단 복제, 전송, 배포 기타 저작권법에 위반되는 방법으로 이용할 경우
저작권법 제136조에 따라 5년 이하의 징역 또는 5천만 원 이하의 벌금에 처해질 수 있습니다.
제 14 조 (유료서비스)
① 당 사이트 및 협력기관이 정한 유료서비스(원문복사 등)는 별도로 정해진 바에 따르며, 변경사항은 시행 전에
당 사이트 홈페이지를 통하여 회원에게 공지합니다.
② 유료서비스를 이용하려는 회원은 정해진 요금체계에 따라 요금을 납부해야 합니다.
제 5 장 계약 해지 및 이용 제한
제 15 조 (계약 해지)
회원이 이용계약을 해지하고자 하는 때에는 [가입해지] 메뉴를 이용해 직접 해지해야 합니다.
제 16 조 (서비스 이용제한)
① 당 사이트는 회원이 서비스 이용내용에 있어서 본 약관 제 11조 내용을 위반하거나, 다음 각 호에 해당하는
경우 서비스 이용을 제한할 수 있습니다.
- 2년 이상 서비스를 이용한 적이 없는 경우
- 기타 정상적인 서비스 운영에 방해가 될 경우
② 상기 이용제한 규정에 따라 서비스를 이용하는 회원에게 서비스 이용에 대하여 별도 공지 없이 서비스 이용의
일시정지, 이용계약 해지 할 수 있습니다.
제 17 조 (전자우편주소 수집 금지)
회원은 전자우편주소 추출기 등을 이용하여 전자우편주소를 수집 또는 제3자에게 제공할 수 없습니다.
제 6 장 손해배상 및 기타사항
제 18 조 (손해배상)
당 사이트는 무료로 제공되는 서비스와 관련하여 회원에게 어떠한 손해가 발생하더라도 당 사이트가 고의 또는 과실로 인한 손해발생을 제외하고는 이에 대하여 책임을 부담하지 아니합니다.
제 19 조 (관할 법원)
서비스 이용으로 발생한 분쟁에 대해 소송이 제기되는 경우 민사 소송법상의 관할 법원에 제기합니다.
[부 칙]
1. (시행일) 이 약관은 2016년 9월 5일부터 적용되며, 종전 약관은 본 약관으로 대체되며, 개정된 약관의 적용일 이전 가입자도 개정된 약관의 적용을 받습니다.