• Title/Summary/Keyword: inhibitory mechanism

Search Result 1,033, Processing Time 0.028 seconds

ANTICANCER EFFECTS OF CAESALPINIA SAPPAN EXTRACTS ON ORAL CARCINOMA AND OSTEOSARCOMA CELLS (소목 추출물의 구강암 및 골육종 세포주에 대한 항암작용에 관한 연구)

  • Lee, Jong-Su;Kim, Jeong-Hee;Kim, Yeo-Gab
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • v.33 no.6
    • /
    • pp.583-590
    • /
    • 2007
  • Anticancer effect of methanol extract of Caesalpinia sappan L. on oral carcinoma(KB) and osteosarcoma(HOS) cells were investigated in this study. In order to elucidate the anticancer mechanism of Caesalpinia sappan L, we analyzed telomerase inhibitory effect of the methanol extract of Caesalpinia sappan L. In addition, we prepared 5 fraction samples according to its polarity differences and analyzed anticancer effects on oral carcinoma and osteosarcoma cells. Following results are obtained in this study. 1. 50% cell proliferation inhibitory value($IC_{50}$) of the methanol extract of Caesalpinia sappan L. against oral carcinoma(KB) cells and osteosarco ma(HOS) cells were $9.0{\mu}g/ml\;and\;10.9{\mu}g/ml$, respectively. 2. The methanol extract of Caesalpinia sappan L. showed inhibitory effect of telomerase which is required for cancer cell immortality. Therefore, it seems that the anticancer effect of methanol extract of Caesalpinia sappan is at least partially due to telomerase inhibitory effect. 3. Five fraction samples were prepared according to its polarity and 88.7% of ingredient of total methanol extract was transferred to ethylacetate fraction. Thin layer chromatography analysis showed that dichloromethane fraction contained ingredient with relatively high polarity and ethylacetate fraction contained similar ingredient found in total methanol extract. 4. Anticancer effect was observed in n-hexane, dichloromethane, and ethylacetate fractions. The highest anticancer effect was found in dichloromethane fraction which had $IC_{50}$ value of $4.4{\mu}g/ml$ and > $4.0{\mu}g/ml$ against oral carcinoma(KB) cells and osteosarcoma(HOS) cells, respectively.

Inhibitory Effect of Licorice Ethanol Extracts and Glycyrrhizin on Cytochrome P450 Drug-Metabolizing Enzymes in Human Liver Microsomes (감초 물 추출물 및 Glycyrrhizin이 인체 간 Microsome에서 Cytochrome P450 약물대사효소에 미치는 영향)

  • Park Jong-Hoon;Park Ji-Young;Ju Young-Sung
    • Journal of Society of Preventive Korean Medicine
    • /
    • v.7 no.2
    • /
    • pp.65-74
    • /
    • 2003
  • Objective : The aim of present study is to evaluate the inhibitory potential of licorice extract and glycyrrhizin on cytochrome P450(CYP) in human liver microsomes. Methods : Using human liver microsomes, water extract of licorice and glycyrrhizin as an inhibitor were co-incubated with each probe drug representing selective CYP isoform activity. We measured relative metabolic activity in incubation condition compared to that with no extract of licorice using HPLC system. Results : Both water extracts of licorice and glycyrrhizin showed inhibitory effect on CYP-catalyzed reactions. CYP2C19 $(IC_{50}=126.7{\mu}g/ml)$ is most potently inhibited by water extract than other tested CYP isoforms$(IC_{50}>450{\mu}g/ml)$, but glycyrrhizin exhibited potent inhibition on CYP1A2$(IC_{50}=106.9{\mu}g/ml)$ followed by CYP2C9 and CYP2D6. Conclusion: These results indicate that water extract of licorice and glycyrrhizin have inhibitory potential on CYP-catalyzed reaction in human liver microsomes. But the mechanism of inhibition was slightly different between them Water extract of licorice mainly inhibited CYP2C19, and glycyrrhizin primarily inhibited CYP1A2. The inhibition by water extract of licorice and glycyrrhizin on CYP isoforms may cause drug interaction with co-administered drug leading to toxicity or treatment failure.

  • PDF

Arachidonic Acid Ingibits Norepinephrine Release through Blocking of Voltage-sensitive $Ca^{2+}$ Channels in PC12 Cells

  • Choi, Se-Young;Park, Tae-Ju;Choi, Jun-Ho;Kim, Kyong-Tai
    • Animal cells and systems
    • /
    • v.1 no.1
    • /
    • pp.81-86
    • /
    • 1997
  • We studied the mechanism of arachidonic acid on the secretion of a neurotransmitter in rat pheochromocytoma PC12 cells. Arachidonic acid inhibited the 70 mM $K^+$-induced secretion of norepinephrine. Arachidonic acid also inhibited the 70 mM $K^+$-induced $Ca^{2+}$ mobilization which is due to the opening of the voltage-sensitive $Ca^{2+}$ channels (VSCC). Both the half maximal inhibitory concentration ($IC_{50}$) of the norepinephrine secretion and VSCC coincided at 30 uM. The major oxidized metabolites of arachidonic acid, prostaglandins did not mimic the inhibitory effect of arachidonic acid. Nordihydroguaiaretic acid (NDGA) and indomethacin which are inhibitors of lipoxygenase and cyclooxygenase, respectively, did not block the inhibitory effect of arachidonic acid. The results suggest that arachidonic acid serves as a signal itself, not in the form of metabolites. The pretreatment of various $K^+$ channel blockers such as 4-aminopyridine, tetraethylarnmonium, glipizide, or glibenclamide also did not show any effect on the inhibitory effect of arachidonic acid. Through these results we suggest that arachidonic acid regulates VSCC directly and affects the secretion of neurotransmitters.

  • PDF

Inhibitory Effects of Campsis grandiflora on HIV-1 reverse Transcriptase, HIV-1 Protease and α-glucosidase (능소화 잎 및 줄기 추출물의 Human Immunodeficiency Virus Type I 억제활성)

  • Yu, Young-Beob
    • Korean Journal of Plant Resources
    • /
    • v.25 no.2
    • /
    • pp.169-175
    • /
    • 2012
  • For the elucidation of action mechanism on anti-HIV of natural resources, the extracts of $Campsis$ $grandiflora$ were tested for their inhibitory effects on HIV-1 replication and its essential enzymes as the reverse transcriptase (RT), protease and ${\alpha}$-glucosidase. In the assay of HIV-1-infected human T-cell line, water extracts of stem inhibited the HIV-1-induced cytopathic effects with IC (inhibitory concentration) of 100 ${\mu}g$/ml. Moreover water extracts (100 ${\mu}g$/ml) of stem showed strong activity of 37.9% on anti-HIV-1 RT using Enzyme Linked Oligonucleotide Sorbent Assay (ELOSA) method. In the HIV-1 protease inhibition assay, methanol extracts of stem and leaf extract showed 33.6% and 31.5% inhibition of the enzyme activity to cleave an oligopeptide resembling one of the cleavage sites in the viral polyprotein which can only be processed by HIV-1 protease, but did not exhibited glucosidase inhibitory activities. From these results, it is suggested that the inhibition of the viral replication $in$ $vitro$ is due to the inhibition of reverse transcriptase by water extracts of stem of $Campsis$ $grandiflora$.

Effect of Corydalis Tuber on the inhibition of proliferation of human uterine leiomyoma cell and apoptotic gene expression (현호색(玄胡索)이 자궁근종세포의 증식 억제와 Apoptosis 관련 유전자 발현에 미치는 영향)

  • Lee, Hee-Jae;Baek, Seung-Hee;Kim, Dong-Chul
    • The Journal of Korean Obstetrics and Gynecology
    • /
    • v.19 no.2
    • /
    • pp.214-225
    • /
    • 2006
  • Purpose : This study was aimed to investigate the inhibitory effect of Corydalis Tuber on the proliferation of human uterine leiomyoma cell and the expression of gene related the mechanism of cell apoptosis. Methods : We counted the number of suvival cells treated with indicated concentration of Corydalis Tuber and investigated cell viability by MTS assay. Furthermore, flow cytometric analyis were used to dissect between necrosis and apoptosis related with cell cycle and then we observed the differential gene expression by western blot analysis. Results : 1) The inhibitory effect on the proliferation of uterine leiomyoma cell treated with Corydalis Tuber was increased in a concentration and time proportional. 2) The result of flow cytometry analysis, subG1 phase arrest related cell apoptosis was not investigated in uterine leiomyoma cell treated Corydalis Tuber but showed G2/M phase prolongation. 3) The gene expression of p27, p21 related cell cycle was increased according to increasing concentration, but p53 was not exchanged. 4) The dephosphorylation of pRb gene were increased dependent on treatment concentration and pro-caspase 3, CDK4 were not exchanged. Conclusion : This study showed that Corydalis Tuber have the inhibitory effect on the proliferation of human uterine leiomyoma cell but the effect was thoughted no relationship with apoptosis. The inhibitory effect was suggested that dephosphorylation of pRb gene induced with increasing p21, p27 prolonged cell division in G2/M phase.

  • PDF

Effect of Hyulbuchukeotang on the Inhibition of Proliferation of Uterine leiomyoma cells and Cell apoptosis (혈부축어탕(血府逐瘀湯) 자궁근종세포의 증식억제와 Apoptosis 관련 유전자 발현에 미치는 영향)

  • Moon, Na-Young;Baek, Seung-Hee;Kim, Dong-Chul
    • The Journal of Korean Obstetrics and Gynecology
    • /
    • v.19 no.2
    • /
    • pp.186-198
    • /
    • 2006
  • Purpose : The purpose of this study is to demonstrate the direct inhibitory effect of Hyulbuchukeotang on the proliferation of uterine leiomyoma cells through an experiment treating uterine leiomyoma cells cultivated by explantation with indicated concentrations of Hyulbuchukeotang and to research the gene expression related to cell cycle ill order to discover the connection with apoptosis and its mechanism by analyzing cell cycle. Methods : After primary culture of uterine leiomyoma cells, the cultivated uterine leiomyoma cells were treated with indicated concentrations of Hyulbuchukeotang for 24 hours. The inhibitory effect on the cell proliferation was determined by the cell count assay. The value of a cell count assay represent the percentage of cells in a phase of the cell cycle compared with total cells. In addition, a link between Hyulbuchukeotang and apoptosis was examined through flow cytometric analysis by FACS and DNA fragmentation analysis. Finally, the degree of gene expression related to cell cycle was evaluated by Western blot analysis. Results : The inhibitory effect of Hyulbuchukeotang increase of uterine leiomyoma cells treated with indicated concentrations of Hyulbuchkeotang increases. The result of gene expression related to G1 phase after treating with 100, 250, 500, 1,000 ${\mu}g/ml$ concentrations of Hyulbuchukeotang. on uterine leiomyoma cells is that the gene expression of p27 was increased but that of p53 an p21 remained unchanged and the gene of pRB, pro-caspase 3 was decreased. Conclusion Through the mentioned experiments, it is demonstrated that Hyulbuchkeotang is effective in inhibiting Proliferation of uterine leiomyoma cells by extending cell cycle G1. However it is not considered that the inhibitory effect results from the aptoposis.

  • PDF

The Study of $NF-{\kappa}B(P50)$ Suppression mechanism with main Component of Bee Venom and Melittin on Human Synoviocyte

  • Kwon, Soon-Jung;Song, Ho-Sueb
    • Journal of Acupuncture Research
    • /
    • v.22 no.2
    • /
    • pp.123-132
    • /
    • 2005
  • Melittin,cationic 26-amino acid, is the principal component of the bee venom (BV) which has been used for treatment of inflammatory disease such as arthritis rheumatism NF-kB is activated by subsequent release of inhibitory IkB via activation of a multisubunit IkB kinase (IKK). We previously found that melittin bind to the sulfhydryl group of p50, a subunit of NF-kB. Since sulfhydryl group is present in kinase domain of IKKa and IKKb, melittin could modify IKK activity by protein-protein interaction. We therefore examined effect of melittin on IKK activities in sodium nitroprusside (SNP)-stimulated synoviocyte obtained from RA patients. Melittin suppressed the SNP-induced release of IkB resulted in inhibition of DNA binding activity of NF-kB and NF-kB-dependent luciferase activity. Consistent with the inhibitory effect on NF-kB activation, IKKa and IKKb activities were also suppressed by melittin. Surface plasmon resonance analysis realized that melitin binds to IKKa $(Kd\;=\;1.34{\times}10-9M)$ and IKKb$(Kd\;=\;1.0{\times}10-9M)$. Inhibition of IKKa and IKKb resulted in reduction of the SNP-induced production of inflammatory mediators NO and PGE2 generation. The inhibitory effect of melittin on the IKKs activities, binding affinity of melittin to IKKs, and NO and PGE2 generation were blocked by addition of reducing agents dithiothreitol and glutathione. In addition, melittin did not show inhibitory effect in the transfected Synoviocytes with plasmid carrying dominant negative mutant IKKa (C178A) and IKKb (C179A). These results demonstrate that melittin directly binds to sulfhydryl group of IKKs resulting in IkBrelease, thereby inhibits activation of NF-kB and expression of genes involving in the inflammatory responses.

  • PDF

Inhibitory Effect of Caffeine on Carbachol-Induced Nonselective Cationic Current in Guinea-Pig Gastric Myocytes

  • Kim, Sung-Joon;Min, Kyung-Wan;Kim, Young-Chul;Lee, Sang-Jin;So, In-Suk;Kim, Ki-Whan
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.2 no.3
    • /
    • pp.353-359
    • /
    • 1998
  • In gastrointestinal smooth muscle, muscarinic stimulation by carbachol (CCh) activates nonselective cation channel current ($I_{CCh}$) which is facilitated by intracellular [$Ca^{2+}$] increase. Caffeine is widely used in experiments to mobilize $Ca^{2+}$ from intracellular stores. This study shows a strong inhibitory effect of caffeine on $I_{CCh}$ in guinea-pig gastric myocyte. In this study, the underlying mechanism of the inhibitory effect of caffeine was investigated. $I_{CCh}$ was completely suppressed by the addition of caffeine (10 mM) to the superfusing solution. Inhibition of $I_{CCh}$ by caffeine was not related to the intracellular cAMP accumulation which was expected from the phosphodiesterase-inhibiting effect of caffeine. The blockade of $InsP_3-induced$ $Ca^{2+}$ release by heparin had no significant effects on the activation of $I_{CCh}$. When the same cationic current had been induced by intracellular dialysis of $GTP[{\gamma}S]$ in order to bypass the muscarinic receptor, the inhibitory effect of caffeine was significantly attenuated. The results of this study indicate that both intracellular signalling pathways for $I_{CCh}$, proximal and distal to G-protein activation, are suppressed by caffeine. A major inhibition was observed at the proximal level.

  • PDF

A Study on Inhibitory Mechanism of Melia Fructus Extract on Osteoclast Differentiation (천연자(川楝子)의 파골세포 분화 억제기전 연구)

  • Yun, Young-Jin;Lee, Jin-Moo;Lee, Chang-Hoon;Jang, Jun-Bock;Lee, Kyung-Sub
    • The Journal of Korean Obstetrics and Gynecology
    • /
    • v.25 no.2
    • /
    • pp.1-11
    • /
    • 2012
  • Objectives: This study was conducted to evaluate the inhibitory effect of Melia Fructus extract on osteoclast differentiation. Methods: MTT-assay was performed to estimate cytotoxicity of Melia Fructus extract in BMMs stimulated with M-CSF. TRAP staining, TRAP activity and Real-time PCR were performed to know the inhibitory effect on osteoclast differentiation. Actin ring formation were analysed to observe the effect of Melia Fructus extract. Results: Melia Fructus extract decreased the number of TRAP positive cells and the expression of NFATc1 gene, c-Fos gene, TRAP and OSCAR in BMMs stimulated with RANKL. Melia Fructus extract has no cytotoxicity at the concentration used in this study. Melia Fructus extract restrained the formation of actin ring. Melia Fructus inhibited NF-${\kappa}B$ activity by inducing degradation of p-$IkB{\alpha}$. Conclusions: Melia Fructus has the inhibitory effect of osteocalst differentiation and bone resorption. Further studies are needed to treat osteoporosis by herbal medicine containing Melia Fructus.

The Effect of Sihosogansangagambang (SS) on Melanin Synthesis and gene expression in B16F10 Mouse Melanoma Cell (시호소간산가감방(柴胡疎肝散加減方)이 멜라닌 생성 및 유전자발현에 미치는 영향)

  • Kim, Ju-Young;Lim, Hyun-Jung;Shin, Sun-Mi;Yoo, Dong-Youl
    • The Journal of Korean Obstetrics and Gynecology
    • /
    • v.22 no.1
    • /
    • pp.95-109
    • /
    • 2009
  • Purpose: This study was performed to determine the inhibitory effect of Sihosogansangagambang (SS) on melanin synthesis in B16F10 melanoma cells (B16F10). Methods: The inhibitory effects of Sihosogansangagambang on melanin synthesis were used by in vitro assay. To elucidate inhibitory effects of SS on melanin synthesis, we determined the melanin release in B16F10. And to investigate the mechanism of inhibitory effect of SS, we assessed the gene expression of tyrosinase, TRP-1, TRP-2 and ERK-1 in B16F10. Results: 1. SS decreased the release of melanin in B16F10 melanoma cells. 2. SS inhibited mushroom tyrosinase activity in vitro. 3. SS decreased the expression of tyrosinase, TRP-2 in B16F10 melanoma cells, but did not decreased the expression of TRP-1 in B16F10 melanoma cells. 4. SS decreased the expression of ERK-1 in B16F10 melanoma cells. Conclusion: From these results, it may be suggested that SS is possesed of the antimelanogenetic effects.