• BMB Reports
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• v.41 no.11
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• pp.765-770
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• 2008

Undesirable hyperpigmentation that can arise from increased melanocyte activity may be alleviated by targeting active melanocytes for apoptosis. The role of Stathmin 1 as an important regulator of microtubule dynamics is well documented. The current study examined the potential of Stathmin 1-targeting strategies in eliminating active melanocytes. A vector to overexpress Stathmin 1 and vectors to express three distinct small hairpin RNAs to knockdown Stathmin 1 expression in normal melanocytes were produced and in cell cultures acted accordingly. Both overexpression and knockdown of Stathmin 1 led to a marked increase in melanocyte apoptosis, as indicated by the accumulation of apoptotic cells and increased levels of cleaved caspase-3. Both up- and down-regulation of Stathmin 1 expression inhibited the activity of differentiated melanocytes, as indicated by decreases in both melanin production and tyrosinase activity. Taken together, these results indicate that hyperactive melanocytes can be inhibited by altering Stathmin 1 expression.

• Journal of Ginseng Research
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• v.48 no.1
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• pp.59-67
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• 2024

Background: Alzheimer's disease (AD) has memory impairment associated with aggregation of amyloid plaques and neurofibrillary tangles in the brain. Although anti-amyloid β (Aβ) protein antibody and chemical drugs can be prescribed in the clinic, they show adverse effects or low effectiveness. Therefore, the development of a new drug is necessarily needed. We focused on the cognitive function of Panax ginseng and tried to find active ingredient(s). We isolated panaxcerol D, a kind of glycosyl glyceride, from the non-saponin fraction of P. ginseng extract. Methods: We explored effects of acute or sub-chronic administration of panaxcerol D on cognitive function in scopolamine- or Aβ_25-35 peptide-treated mice measured by several behavioral tests. After behavioral tests, we tried to unveil the underlying mechanism of panaxcerol D on its cognitive function by Western blotting. Results: We found that pananxcerol D reversed short-term, long-term and object recognition memory impairments. The decreased extracellular signal-regulated kinases (ERK) or Ca²⁺/calmodulin-dependent protein kinase II (CaMKII) in scopolamine-treated mice was normalized by acute administration of panaxcerol D. Glial fibrillary acidic protein (GFAP), caspase 3, NF-kB p65, synaptophysin and brainderived neurotrophic factor (BDNF) expression levels in Aβ_25-35 peptide-treated mice were modulated by sub-chronic administration of panaxcerol D. Conclusion: Pananxcerol D could improve memory impairments caused by cholinergic blockade or Aβ accumulation through increased phosphorylation level of ERK or its anti-inflammatory effect. Thus, panaxcerol D as one of non-saponin compounds could be used as an active ingredient of P. ginseng for improving cognitive function.

• Journal of Life Science
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• v.19 no.2
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• pp.163-168
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• 2009

To understand cytotoxic activity of Rubia cordifolia L. (Rubiaceae), which has been used as a traditional oriental medicine, the mechanism underlying cytotoxic effect of its extract on human acute Jurkat T cells was investigated. The methanol extract of roots (3 kg) of R. codifolia was evaporated, dissolved in water, and then extracted by dichloromethane. The substances in the chloroform extract showing the most cytotoxic activity were further purified by a series of preparative HPLC. The extracted active substance (65 mg) was designated as CCH1. When Jurkat T cells were treated with CCH1 at concentration ranging from 0.5 to 2.0 ${\mu}g$/ml, apoptotic phenomena of cells companying several subsequent biochemical reactions such as mitochondria cytochrome c release, activation of casapase-8, -9, and caspase- 3, degradation of PARP and DNA fragmentation occurred via mitochondria-dependent pathway. However, abrogation of apoptosis was observed in an ectopic expression of Bcl-xL, which is a suppressor for mitochondrial cytochrome c release. These results demonstrate that the cytotoxicity of CCH1 against Jurkat T cells is attributable to apoptosis mediated by mitochodria-dependent death-signaling regulated by Bcl-xL. In addition, the CCH1 is more potent to leukemia Jurkat T cell than to human peripheral blood monocyte cells (PBMC).

• Journal of Life Science
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• v.27 no.8
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• pp.951-957
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• 2017

To understand the cytotoxic activity of Machilus thunbergii, which has been used as a traditional oriental medicine, the mechanism underlying the cytotoxic effect of its extract on human acute Jurkat T cells was investigated. The methanol extract of roots (3 kg) of M. thunbergii was evaporated, dissolved in, and then extracted by water. The water-extracted active substance was designated MTWE. When Jurkat T cells were treated with MTWE at concentrations of 0, 25, 50, and $100{\mu}g/ml$, the apoptotic phenomenon of cells accompanying several subsequent biochemical reactions, such as mitochondrial cytochrome c release, activation of caspase-3, and ICAD degradation, was detected in the Jurkat T cells. Moverover. the expression of Bcl-xL, which is a suppressor for mitochondrial cytochrome c release pathway, was reduced in the Jurkat T cells. As DUSP6, a growth suppressor of cancer cells, ranged from 0, 25, 50, $100{\mu}g/ml$ of MTWE, the expression level was elevated in the Jurkat T cells. The apoptotic morphological change of the nuclei was observed by DAPI staining. Although the potential involvement of the other factors and DUSP6 is currently being investigated in more detail, these findings support the notion that MTWE is able to achieve the apoptosis of Jurkat T cells, and it seems that MTWE is useful as a method of evaluating a chemotherapeutic agent or tonic materials for human acute leukemia.

• Archives of Pharmacal Research
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• v.25 no.5
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• pp.561-571
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• 2002

The action mechanisms of several chemopreventive agents derived from herbal medicine and edible plants have become attractive issues in cancer research. Tea is the most widely consumed beverage worldwide. Recently, the cancer chemopreventive actions of tea have been intensively investigated. It have been demonstrated that the active principles of tea were attributed to their tea polyphenols. Recently, tremendous progress has been made in elucidating the molecular mechanisms of cancer chemoprevention by tea and tea polyphenols. The suppression of various tumor biomarkers including growth factor receptor tyrosine kinases, cytokine receptor kinases, P13K, phosphatases, ras, raf, MAPK cascades, NㆍFB, IㆍB kinase, PKA, PKB, PKC, c-jun, c-fos, c-myc, cdks, cyclins, and related transducing proteins by tea polyphenols has been studied in our laboratory and others. The IㆍB kinase (IKK) activity in LPS-activated murine macrophages (RAW 264.7 cells) was found to be inhibited by various tea polyphenols including (-) epigallocatechin-3-gallate (EGCG), theaflavin (TF-1), theaflavin-3-gal-late (TF-2) and theaflavin-3,3'-digallate (TF-3). TF-3 inhibited IKK activity in activated macrophages more strongly than did the other tea polyphenols. TF-3 inhibited both IKK1 and IKK2 activity and prevented the degradation of IㆍBㆍand IㆍBㆍin activated macrophage cells. The results suggested that the inhibition of IKK activity by TF-3 and other tea polyphenols could occur by a direct effect on IKKs or on upstream events in the signal transduction pathway. TF-3 and other tea polyphenols blocked phosphorylation of IB from the cytosolic fraction, inhibited NFB activity and inhibited increases in inducible nitric oxide synthase levels in activated macrophage. TF-3 and other tea polyphenols also inhibited strongly the activities of xanthine oxidase, cyclooxygenase, EGF-receptor tyrosine kinase and protein kinase C. These results suggest that TF-3 and other tea polyphenols may exert their cancer chemoprevention through suppressing tumor promotion and inflammation by blocking signal transduction. The mechanisms of this inhibition may be due to the blockade of the mitogenic and differentiating signals through modulating EGFR function, MAPK cascades, NFkB activation as wll as c-myc, c-jun and c-fos expression.

• Korean Journal of Medicinal Crop Science
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• v.26 no.2
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• pp.141-147
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• 2018

Background: Astilbe chinensis (Maxim.) Franch. Et Savat. is a plant belonging to Saxifragaceae family and contains various active ingredients including astilbin and bergenin. It has been used as a traditional Korean medicine to improve fever, pain, and cough. Recently, a number of Korean medical resources have been studied for cancer and inflammation treatment, but A. chinensis (Maxim.) Franch. Et Savat. has not yet been investigated. Consequently, this study investigated the inhibitory effect of ethanol extracts from A. chinensis (Maxim.) Franch. Et Savat. (ARE) on oxidative stress and colorectal cancer using RAW264.7 and the human colorectal cancer cell line HCT-116. Methods and Results: In total, $500{\mu}g/m{\ell}$ ARE reduced cell viability by $38.96{\pm}1.32%$, and increased caspase-3 activity by $133.08{\pm}3.41%$ in HCT-116 cells. Moreover, TUNEL signaling and the early apoptosis ratio ($34.56{\pm}1.67%$) increased by $500{\mu}g/m{\ell}$ ARE treatment. $H_2O_2$-induced oxidative stress and cell death were diminished by $500{\mu}g/m{\ell}$ ARE treatment through decreasing ROS (reactive oxygen species). Conclusions: The inhibitory effects of ARE against human colorectal cancer cells is mediated by apoptosis and caspase-3 activation, and $H_2O_2$-induced ROS generation and cell death are decreased by ARE treatment in RAW264.7 cells. However, further study is required to explore how ARE treatment is involved in the signaling pathway to decrease ROS.

• Journal of Life Science
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• v.23 no.10
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• pp.1223-1229
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• 2013

Ursolic acid (UA) a bio-active ingredient found in a variety of fruits and vegetables, and it has potent antioxidant activity. However, the role of UA in mouse embryonic stem (ES) cells is poorly understood. This study investigated the functional role of UA in regulating the development of mouse ES cells under hypoxia. Hypoxia did not exert a significant effect on the undifferentiated state of mouse ES cells. However, it induced reactive oxygen species (ROS) generation and increased the level of lactate dehydrogenase (LDH) production at 48 h of hypoxic exposure. Conversely, oxidative stress induced by hypoxia was significantly inhibited by UA ($30{\mu}M$) pretreatment. Hypoxia significantly decreased cell survival and the level of [$^3H$] thymidine incorporation, both of which recovered following pretreatment of UA. In addition, UA decreased the apoptotic effect of hypoxia by attenuating caspase-3 cleavage or by recovering cellular inhibition of the apoptotic protein (cIAP)-2 and Bcl-2 expression. We further found that UA decreased senescence-associated beta-galactosidase activity. We suggest that UA is a natural antioxidant and one of the functional modulators of hypoxia-induced survival, apoptosis, proliferation, and aging in mouse ES cells.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.sup3
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• pp.125-130
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• 2016

Nepeta cataria L. has been used in traditional medicine of some countries. Here the cytotoxic and apoptogenic activity of methanol extracts, n-hexane, dichloromethane, ethyl acetate, n-butanol, and acqueous extracts and the essential oil obtained from the aerial parts of the plant were evaluated with PC3, DU-145 and MCF-7 cell lines. Cell viability, histograms of PI stained fragmented DNA in apoptotic cells and Western blot analysis of proteins involved in the cascade of apoptosis were compared in all samples. Thirty components were identified as volatile, representing 99.7% of essential oil composition after GC-MS analysis of the oil obtained from aerial parts of the N. cataria by hydro-distillation. The major oil components of the essential oil were nepetalactone stereoisomers. Comparing IC50 values showed estrogen receptor positive PC3 cells were more sensitive to the cytotoxic effects of N. cataria in comparison with low hormone-receptor presenting DU-145 cells. Among multiple extracts and essential oils of the plant, only the ethyl acetate extract could significantly decrease cell viability in PC3 cells, in a concentration dependent manner. Ethyl acetate extract of N. cataria treated cells showed a sub-G1 peak in PC3 cells in a concentration dependent manner that indicates the involvement of an apoptotic process in ethyl acetate extract-induced cell death. Western blotting analysis showed that in PC3 cells treated with ethyl acetate (48 h) caspase 3 and PARP were cleaved to active forms. Overall, the results suggest that further analytical elucidation of N. cataria in respect to finding new cytotoxic chemicals with anti-tumor activity is warranted.

• Journal of Ginseng Research
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• v.34 no.3
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• pp.246-253
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• 2010

Ginsenoside $Rg_3$ ($Rg_3$), one of the active ingredients in Panax ginseng, attenuates NMDA receptor-mediated currents in vitro and antagonizes NMDA receptors through a glycine modulatory site in rat cultured hippocampal neurons. In the present study, we examined the neuroprotective effects of $Rg_3$ on 24-hydroxycholesterol (24-OH-chol)-induced cytotoxicity in vitro. The results showed that $Rg_3$ treatment significantly and dose-dependently inhibited 24-OH-chol-induced cell death in rat cultured cortical neurons, with an $IC_{50}$ value of $28.7{\pm}7.5\;{\mu}m$. Furthermore, the $Rg_3$ treatment not only significantly reduced DNA damage, but also dose-dependently attenuated 24-OH-chol-induced caspase-3 activity. To study the mechanisms underlying the in vitro neuroprotective effects of $Rg_3$ against 25-OH-chol-induced cytotoxicity, we also examined the effect of $Rg_3$ on intracellular $Ca^{2+}$ elevations in cultured neurons and found that $Rg_3$ treatment dose-dependently inhibited increases in intracellular $Ca^{2+}$, with an $IC_{50}$ value of $40.37{\pm}12.88\;{\mu}m$. Additionally, $Rg_3$ treatment dose-dependently inhibited apoptosis with an $IC_{50}$ of $47.3{\pm}14.2\;{\mu}m$. Finally, after confirming the protective effect of $Rg_3$ using a terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay, we found that $Rg_3$ is an active component in ginseng-mediated neuroprotection. These results collectively indicate that $Rg_3$-induced neuroprotection against 24-OH-chol in rat cortical neurons might be achieved via inhibition of a 24-OH-chol-mediated $Ca^{2+}$ channel. This is the first report to employ cortical neurons to study the neuroprotective effects of $Rg_3$ against 24-OH-chol. In conclusion, $Rg_3$ was effective for protecting cells against 24-OH-chol-induced cytotoxicity in rat cortical neurons. This protective ability makes $Rg_3$ a promising agent in pathologies implicating neurodegeneration such as apoptosis or neuronal cell death.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.6
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• pp.1566-1571
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• 2008

Bone is a dynamic tissue that is constantly resorbed by osteoclasts and then replaced by osteoblasts. Osteoclasts, multinucleated cells of monocyte/macrophage lineage, are responsible for bone disorders, including osteoporosis and rheumatoid arthritis. In this study, we examined the effect of the curcumin on osteoclast survival and bone resorption. We found that curcumin significantly inhibited RANKL-mediated osteoclast survival. DAPI stainingrevealed that curcumin induced the apoptotic features of osteoclasts. Although curcumin did not suppress the phosphorylation of Akt and ERK in osteoclasts treated with RANKL, curcumin induced the cleavage of pro-caspase-9 and -3 its active forms. Also, curcumin inhibited the formation of actin rings of osteoclasts. RANKL-mediated bone resorption was inhibited by the addition of curcumin. Together with the results of this study, these findings suggest that the curcumin inhibited the survival of osteoclasts by activating caspase-9 and -3 and suppressed the bone resorptive activity. Thus, curcumin may be developed as antiresorptive drugs for the treatment of bone-related disorders.