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Rajesh Agarwal - One of the best experts on this subject based on the ideXlab platform.
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Flavanone Silibinin treatment attenuates nitrogen mustard-induced toxic effects in mouse skin.
Toxicology and applied pharmacology, 2015Co-Authors: Anil K. Jain, Neera Tewari-singh, Swetha Inturi, Dileep Kumar, David J. Orlicky, Chapla Agarwal, Carl W. White, Rajesh AgarwalAbstract:Currently, there is no effective antidote to prevent skin injuries by sulfur mustard (SM) and nitrogen mustard (NM), which are vesicating agents with potential relevance to chemical warfare, terrorist attacks, or industrial/laboratory accidents. Our earlier report has demonstrated the therapeutic efficacy of Silibinin, a natural flavanone, in reversing monofunctional alkylating SM analog 2-chloroethyl ethyl sulfide-induced toxic effects in mouse skin. To translate this effect to a bifunctional alkylating vesicant, herein, efficacy studies were carried out with NM. Topical application of Silibinin (1 or 2 mg) 30 min after NM exposure on the dorsal skin of male SKH-1 hairless mice significantly decreased NM-induced toxic lesions at 24, 72 or 120 h post-exposure. Specifically, Silibinin treatment resulted in dose-dependent reduction of NM-induced increase in epidermal thickness, dead and denuded epidermis, parakeratosis and microvesication. Higher Silibinin dose also caused a 79% and 51%reversal in NM-induced increases in myeloperoxidase activity and COX-2 levels, respectively. Furthermore, Silibinin completely prevented NM-induced H2A.X phosphorylation, indicating reversal of DNA damage which could be an oxidative DNA damage as evidenced by high levels of 8-oxodG in NM-exposed mouse skin that was significantly reversed by Silibinin. Together, these findings suggest that attenuation of NM-induced skin injury by Silibinin is duemore » to its effects on the pathways associated with DNA damage, inflammation, vesication and oxidative stress. In conclusion, results presented here support the optimization of Silibinin as an effective treatment of skin injury by vesicants. - Highlights: • Silibinin treatment attenuated nitrogen mustard (NM)-induced skin injury. • Silibinin affects pathways associated with DNA damage, inflammation and vesication. • The efficacy of Silibinin could also be associated with oxidative stress. • These results support testing and optimization of Silibinin against SM-induced skin injury.« less
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Silibinin inhibits prostate cancer cells and rankl induced osteoclastogenesis by targeting nfatc1 nf κb and ap 1 activation in raw264 7 cells
Molecular Carcinogenesis, 2014Co-Authors: Chandagirikoppal V Kavitha, Rajesh Agarwal, Anil K. Jain, Chapla Agarwal, Gagan Deep, Subhash Chander GangarAbstract:Currently, there are limited therapeutic options against bone metastatic prostate cancer (PCA), which is primarily responsible for high mortality and morbidity in PCA patients. Enhanced osteoclastogenesis is an essential feature associated with metastatic PCA in the bone microenvironment. Silibinin, an effective chemopreventive agent, is in phase II clinical trials in PCA patients but its efficacy against PCA cells-induced osteoclastogenesis is largely unknown. Accordingly, here we examined Silibinin effect on PCA cells-induced osteoclastogenesis employing human PCA (PC3MM2, PC3 and C4-2B) and murine macrophage RAW264.7 cells. We also assessed Silibinin effect on receptor activator of nuclear factor B ligand (RANKL)-induced signaling associated with osteoclast differentiation in RAW264.7 cells. Further, we analyzed Silibinin effect on osteomimicry biomarkers in PCA cells. Results revealed that Silibinin (30–90 μM) inhibits PCA cells-induced osteoclast activity and differentiation in RAW264.7 cells via modulating expression of several cytokines (IGF-1, TGF-β, TNF-α, I-TAC, M-CSF, G-CSF, and GM-CSF etc.) that are important in osteoclastogenesis. Additionally, in RAW264.7 cells, Silibinin decreased the RANKL-induced expression and nuclear localization of NFATc1, which is considered the master regulator of osteoclastogenesis. Furthermore, Silibinin decreased the RANKL-induced DNA binding activity of NFATc1 and its regulators NF-κB and AP1, and the protein expression of osteoclast specific markers (TRAP, OSCAR and Cathepsin K). Importantly, Silibinin also decreased the expression of osteomimicry biomarkers (RANKL, Runx2, Osteocalcin and PTHrP) in cell culture (PC3 and C4-2B cells) and/or in PC3 tumors. Together, our findings showing that Silibinin inhibits PCA cells-induced osteoclastogenesis, suggest that Silibinin could be useful clinically against bone metastatic PCA.
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inhibition of azoxymethane induced colonic aberrant crypt foci formation by Silibinin in male fisher 344 rats
Cancer Prevention Research, 2008Co-Authors: Balaiya Velmurugan, Rana P Singh, Alpna Tyagi, Rajesh AgarwalAbstract:Chemoprevention is a practical approach to control colorectal cancer, which is one of the major causes of cancer mortality in the United States. Based on our recent Silibinin efficacy studies in human colorectal cancer cells, we investigated the effects of its dietary feeding on azoxymethane (AOM)-induced aberrant crypt foci (ACF) formation and associated biomarkers in male Fisher 344 rats. Five-week-old male Fisher 344 rats were fed control or Silibinin-supplemented (0.033%, 0.1%, 0.33%, or 1%, w/w) diet. After 2 weeks, AOM was injected once a week for 2 weeks while Silibinin treatments were continued. In another protocol, identical Silibinin treatments were done but started 2 weeks post-AOM initiation. All rats were sacrificed at 16 weeks of age, and colon samples were evaluated for ACF, followed by proliferation, apoptosis, and inducible nitric oxide synthase and cyclooxygenase-2, by immunohistochemistry and/or immunoblotting. Silibinin significantly (P < 0.001) reduced dose-dependently the number and multiplicity of AOM-induced ACF formation. Silibinin feeding in pre- and post-AOM initiation decreased mean number of ACF by 39% to 65% and in post-AOM initiation by 29% to 55%. Silibinin dose-dependently decreased AOM-induced colonic cell proliferation, evidenced by proliferative cell nuclear antigen and cyclin D1 immunohistochemical staining, and induced apoptosis in these colon tissues, evidenced by terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling staining and cleaved poly(ADP-ribose) polymerase. Furthermore, Silibinin significantly decreased AOM-induced inducible nitric oxide synthase- and cyclooxygenase-2-positive cells in colon tissues. The present findings show possible beneficial activity of Silibinin at least in early stage of colon tumorigenesis, suggesting that Silibinin might be an effective natural agent for colorectal cancer chemoprevention.
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stage specific inhibitory effects and associated mechanisms of Silibinin on tumor progression and metastasis in transgenic adenocarcinoma of the mouse prostate model
Cancer Research, 2008Co-Authors: Komal Raina, Rana P Singh, Gagan Deep, Manesh Chittezhath, Subapriya Rajamanickam, Rajesh AgarwalAbstract:Herein, using transgenic adenocarcinoma of the mouse prostate (TRAMP) model, we assessed the “stage-specific” efficacy of Silibinin feeding against prostate cancer (PCa) initiation, progression, angiogenesis and metastasis, and associated molecular events involved in Silibinin effects during these stages. Male TRAMP mice starting at ages 4, 12, 20, and 30 weeks of age were fed with control or 1% Silibinin-supplemented diet for 8 to 15 weeks in stage-specific manners. At the end of studies, Silibinin-fed mice showed less severe prostatic lesions compared with positive controls. During early stages of prostate tumor development, Silibinin mediated its efficacy mostly via antiproliferative mechanisms. Feeding of Silibinin to animals burdened with higher stages of prostate tumor significantly decreased tumor grade via antiproliferative effect, and inhibition of angiogenesis as evidenced by decreased expressions of platelet endothelial cell adhesion molecule-1/CD-31, vascular endothelial growth factor, and associated receptor, vascular endothelial growth factor R2, hypoxia-inducible factor-1α, and inducible nitric oxide synthase. Metastasis to distant organs was decreased in Silibinin-fed mice, which was associated with a decreased expression of matrix metalloproteinases, mesenchymal markers snail-1, and fibronectin in the prostatic tissue and retention of epithelial characteristics. Together, these findings are both novel and highly significant in establishing the dual efficacy of Silibinin where it inhibits progression of primary prostatic tumor and also shows protective efficacy against angiogenesis and late stage metastasis. These effects of Silibinin could have potential implications to improve the morbidity and survival in PCa patients. [Cancer Res 2008;68(16):6822–30]
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Silibinin suppresses in vivo growth of human prostate carcinoma pc 3 tumor xenograft
Carcinogenesis, 2007Co-Authors: Rana P Singh, Gagan Deep, Michael Pollak, Mariejose Blouin, Rajesh AgarwalAbstract:Chemoprevention is an upcoming approach to control cancer including prostate cancer (PCa). Here, we studied the efficacy and associated mechanisms of a chemopreventive agent Silibinin against ectopically growing and established advanced human prostate carcinoma PC-3 tumor xenografts in athymic nude mice. Dietary Silibinin (0.5%, w/w) did not show any adverse health effect in mice. In first protocol, Silibinin started 1 week prior to xenograft implantation and continued for 60 additional days, whereas in the second protocol, Silibinin treatment was started after 25 days of established tumors for 4, 8 and 16 days. Silibinin inhibited tumor growth rate in both protocols showing up to 35% (P = 0.010) and 18-56% (P = 0.002 to <0.001) decrease in tumor volume per mouse and 27% (P < 0.01) and 44% (P = 0.014) decrease in tumor weight per mouse, respectively. In first protocol, Silibinin decreased (P < 0.001) tumor cell proliferation and microvessel density but increased (P < 0.001) apoptosis. An increase in insulin-like growth factor-binding protein-3 (IGFBP-3) expression with a concomitant decrease in vascular endothelial growth factor (VEGF) expression was noted. Silibinin strongly increased phospho-extracellular signal-regulated kinase 1/2 (ERK1/2), Cip1/p21 and Kip1/p27 (cyclin-dependent kinase inhibitors) levels but moderately decreased Bcl-2 and survivin levels. In established tumors, similar biomarkers and molecular changes were observed due to Silibinin corresponding to its antitumor efficacy. These findings identified in vivo antitumor efficacy of Silibinin against PC-3 human PCa in both intervention protocols accompanied with its anti-proliferative, pro-apoptotic and anti-angiogenic activities. At molecular level, Silibinin increased IGFBP-3, Cip1/p21, Kip1/p27 levels and ERK1/2 activation and decreased Bcl-2, survivin and VEGF levels in tumors.
Takashi Ikejima - One of the best experts on this subject based on the ideXlab platform.
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Silibinin-induced mitochondria fission leads to mitophagy, which attenuates Silibinin-induced apoptosis in MCF-7 and MDA-MB-231 cells.
Archives of biochemistry and biophysics, 2020Co-Authors: Weiwei Liu, Satoshi Onodera, Toshihiko Hayashi, Kazunori Mizuno, Shunji Hattori, Hitomi Fujisaki, Takashi IkejimaAbstract:Abstract We reported previously that higher doses (150–250 μM) of Silibinin enhanced fission and inhibited fusion of mitochondria, accompanying apoptosis of double-positive breast cancer cell line MCF-7 cells and triple-negative breast cancer cell line MDA-MB-231 cells. We report here three important questions yet unclarified in the previous study; 1) Whether enhanced fission of mitochondria by the treatment of Silibinin leads to mitophagy, 2) Whether mitophagy positively contributes to apoptosis and 3) Whether estrogen receptor-positive (ER+) MCF-7 cells and estrogen receptor-negative (ER−) MDA-MB-231 cells are affected in a different way by Silibinin treatment, since Silibinin often works through ERs signaling pathway. Mitophagy driven by Pink1/Parkin signaling, plays an important role in eliminating damaged mitochondria. Indeed, increased expression of Pink1 and the recruitment of Parkin and LC3-II to mitochondria by the treatment with Silibinin account for Silibinin induction of mitophagy. In this study, the effects of mitochondrial division inhibitor 1 (mdivi-1) and small interfering RNA targeting dynamin-related protein 1 (DRP1) were examined to reveal the effect of mitochondrial fission on mitophagy. As expected, mdivi-1 or siRNA targeting DRP1 reversed Silibinin-induced mitochondrial fission due to down-regulation in the expression of DRP1. Inhibition of mitochondrial fission by mdivi-1 prevented induction of mitophagy as well as autophagy in both MCF-7 and MDA-MB-231 cells, indicating that Silibinin-induced mitochondrial fission leads to mitophagy. Inhibition of mitochondrial fission efficiently prevented Silibinin-induced apoptosis in MCF-7 and MDA-MB-231 cells in our previous work, and the second point of the present study, inhibition of mitophagy by Pink1 or Parkin knockdown increased Silibinin-induced apoptosis of these cells, respectively, suggesting that the mitophagy induced by Silibinin treatment serves as a cytoprotective effect, resulting in reduction of apoptosis of cancer cells in both cells. In the third point, we studied whether estrogen receptors (ERs) played a role in Silibinin-induced mitophagy and apoptosis in MCF-7 and MDA-MB-231 cells. ERα and ERβ are not involved in Silibinin-induced mitophagic process in MCF-7 and MDA-MB-231 cells. These findings demonstrated that Silibinin induced mitochondria fission leads to mitophagy, which attenuates Silibinin-induced apoptosis not through ERs-Pink1 or -Parkin pathway in MCF-7 and MDA-MB-231.
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Silibinin-induced apoptosis of breast cancer cells involves mitochondrial impairment.
Archives of biochemistry and biophysics, 2019Co-Authors: Weiwei Liu, Satoshi Onodera, Toshihiko Hayashi, Kazunori Mizuno, Shunji Hattori, Yuheng Nie, Takashi IkejimaAbstract:Abstract Mitochondria are dynamically regulated by fission and fusion processes. Silibinin induces apoptosis of MCF-7 and MDA-MB-231 human breast cancer cells. However, whether or not mitochondria dysfunction is involved in the apoptosis induction with Silibinin of both types of the cells remains unknown. We here report that Silibinin decreases the mitochondrial mass in terms of MitoTracker Green staining in both breast cancer cells. Silibinin induces morphological changes of mitochondria from oval to truncated or fragmented shapes accordingly. Condensed crests are observed in mitochondria by transmission electron microscopy. Silibinin causes mitochondrial membrane potential reduced. The expression of mitochondrial fission-associated proteins including dynamin-related protein 1 (DRP1) is up-regulated, whereas expression of the mitochondrial fusion-associated proteins, optic atrophy 1 and mitofusin 1, is down-regulated. In addition, Silibinin treatment down-regulates ATP content as well as the levels of mitochondrial biogenesis-regulators including mitochondrial transcription factor A, peroxisome proliferator-activated receptor gamma coactivator 1 and nuclear respiratory factor 2. Moreover, treatments with DRP1 inhibitor, mdivi-1, or with DRP1-targetted siRNA efficiently prevent Silibinin-induced apoptosis in the breast cancer cells, whereas inhibition of DRP1 phosphorylation with staurosporine increases apoptosis furthermore. Taken together, we conclude that Silibinin impairs mitochondrial dynamics and biogenesis, leading to apoptosis of MCF-7 and MDA-MB-123 cells.
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Silibinin ameliorates anxiety depression like behaviors in amyloid β treated rats by upregulating bdnf trkb pathway and attenuating autophagy in hippocampus
Physiology & Behavior, 2017Co-Authors: Xiaoyu Song, Shin-ichi Tashiro, Weiwei Liu, Toshihiko Hayashi, Shunji Hattori, Bo Liu, Lingyu Cui, Biao Zhou, Yuko Ushikikaku, Takashi IkejimaAbstract:Depression is one of the most frequent psychiatric disorders of Alzheimer's disease (AD). Depression and anxiety are associated with increased risk of developing AD. Silibinin, a flavonoid derived from milk thistle (Silybum marianum), has been used as a hepato-protectant in the clinical treatment of liver diseases. In this study, the effect of Silibinin on Aβ-induced anxiety/depression-like behaviors in rats was investigated. Silibinin significantly attenuated anxiety/depression-like behaviors caused by Aβ1-42-treatment as shown in tail suspension test (TST), elevated plus maze (EPM) and forced swimming tests (FST). Moreover, Silibinin was able to attenuate the neuronal damage in the hippocampus of Aβ1-42-injected rats. Silibinin-treatment up-regulated the function through BDNF/TrkB pathway and attenuated autophagy in the hippocampus. Our study provides a new insight into the protective effects of Silibinin in the treatment of anxiety/depression.
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Silibinin induced autophagic and apoptotic cell death in ht1080 cells through a reactive oxygen species pathway
Journal of Pharmacological Sciences, 2010Co-Authors: Wenjun Duan, Shin-ichi Tashiro, Satoshi Onodera, Qisheng Li, Takashi IkejimaAbstract:Hepatoprotectant Silibinin has anticancer and chemo-preventive effects. In this study, Silibinin showed significant inhibitory effect on human fibroblast HT 1080 cell growth cultured in media containing 10% fetal bovine serum or in serum free media, and in the latter case, Silibinin exerted a more significant effect. Silibinin induced autophagy at 12 h, confirmed by monodansylcadervarine (MDC) staining, up-regulation of Beclin 1 (initiation factor for autophagosome formation), and conversion of LC3 I to LC3 II (autophagosome marker). It also induced apoptosis at 24 h, proved by observation of apoptotic body and activation of caspase-3. 3-Methyladenine (3-MA) inhibited Silibinin-induced autophagy and promoted cell survival, suggesting that autophagy enhanced Silibinin-induced apoptosis in HT1080 cells. Silibinin generated reactive oxygen species (ROS) in HT1080 cells, and the ROS scavenger N-acetylcysteine (NAC) reversed the cytotoxicity of Silibinin, resulting in cell survival by inhibition of autophagic and apoptotic pathways. Application of specific antioxidants demonstrated that H2O2 was a major factor in Silibinin-induced ROS since the H2O2 scavenger catalase reduced both autophagy and cell death. O2•− also contributed to Silibinin-induced cell death.
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Silibinin induces protective superoxide generation in human breast cancer MCF-7 cells.
Free radical research, 2009Co-Authors: Hong-jun Wang, Shin-ichi Tashiro, Satoshi Onodera, Yuan-yuan Jiang, Xiao-feng Wei, Huang Huai, Takashi IkejimaAbstract:AbstractThe pharmacological activity of polyphenolic Silibinin from milk thistle (Silybum marianum) is primarily due to its antioxidant property. However, this study found that Silibinin promoted sustained superoxide (O2·–) production that was specifically scavenged by exogenous superoxide dismutase (SOD) in MCF-7 cells, while the activity of endogenous SOD was not changed by Silibinin. Previous work proved that Silibinin induced MCF-7 cell apoptosis through mitochondrial pathway and this study further proved that O2·– generation induced by Silibinin was also related to mitochondria. It was found that respiratory chain complexes I, II and III were all involved in Silibinin-induced O2·– generation. Moreover, it was found that Silibinin-induced O2·– had protective effect, as exogenous SOD markedly enhanced Silibinin-induced apoptosis.
Rana P Singh - One of the best experts on this subject based on the ideXlab platform.
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inhibition of azoxymethane induced colonic aberrant crypt foci formation by Silibinin in male fisher 344 rats
Cancer Prevention Research, 2008Co-Authors: Balaiya Velmurugan, Rana P Singh, Alpna Tyagi, Rajesh AgarwalAbstract:Chemoprevention is a practical approach to control colorectal cancer, which is one of the major causes of cancer mortality in the United States. Based on our recent Silibinin efficacy studies in human colorectal cancer cells, we investigated the effects of its dietary feeding on azoxymethane (AOM)-induced aberrant crypt foci (ACF) formation and associated biomarkers in male Fisher 344 rats. Five-week-old male Fisher 344 rats were fed control or Silibinin-supplemented (0.033%, 0.1%, 0.33%, or 1%, w/w) diet. After 2 weeks, AOM was injected once a week for 2 weeks while Silibinin treatments were continued. In another protocol, identical Silibinin treatments were done but started 2 weeks post-AOM initiation. All rats were sacrificed at 16 weeks of age, and colon samples were evaluated for ACF, followed by proliferation, apoptosis, and inducible nitric oxide synthase and cyclooxygenase-2, by immunohistochemistry and/or immunoblotting. Silibinin significantly (P < 0.001) reduced dose-dependently the number and multiplicity of AOM-induced ACF formation. Silibinin feeding in pre- and post-AOM initiation decreased mean number of ACF by 39% to 65% and in post-AOM initiation by 29% to 55%. Silibinin dose-dependently decreased AOM-induced colonic cell proliferation, evidenced by proliferative cell nuclear antigen and cyclin D1 immunohistochemical staining, and induced apoptosis in these colon tissues, evidenced by terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling staining and cleaved poly(ADP-ribose) polymerase. Furthermore, Silibinin significantly decreased AOM-induced inducible nitric oxide synthase- and cyclooxygenase-2-positive cells in colon tissues. The present findings show possible beneficial activity of Silibinin at least in early stage of colon tumorigenesis, suggesting that Silibinin might be an effective natural agent for colorectal cancer chemoprevention.
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stage specific inhibitory effects and associated mechanisms of Silibinin on tumor progression and metastasis in transgenic adenocarcinoma of the mouse prostate model
Cancer Research, 2008Co-Authors: Komal Raina, Rana P Singh, Gagan Deep, Manesh Chittezhath, Subapriya Rajamanickam, Rajesh AgarwalAbstract:Herein, using transgenic adenocarcinoma of the mouse prostate (TRAMP) model, we assessed the “stage-specific” efficacy of Silibinin feeding against prostate cancer (PCa) initiation, progression, angiogenesis and metastasis, and associated molecular events involved in Silibinin effects during these stages. Male TRAMP mice starting at ages 4, 12, 20, and 30 weeks of age were fed with control or 1% Silibinin-supplemented diet for 8 to 15 weeks in stage-specific manners. At the end of studies, Silibinin-fed mice showed less severe prostatic lesions compared with positive controls. During early stages of prostate tumor development, Silibinin mediated its efficacy mostly via antiproliferative mechanisms. Feeding of Silibinin to animals burdened with higher stages of prostate tumor significantly decreased tumor grade via antiproliferative effect, and inhibition of angiogenesis as evidenced by decreased expressions of platelet endothelial cell adhesion molecule-1/CD-31, vascular endothelial growth factor, and associated receptor, vascular endothelial growth factor R2, hypoxia-inducible factor-1α, and inducible nitric oxide synthase. Metastasis to distant organs was decreased in Silibinin-fed mice, which was associated with a decreased expression of matrix metalloproteinases, mesenchymal markers snail-1, and fibronectin in the prostatic tissue and retention of epithelial characteristics. Together, these findings are both novel and highly significant in establishing the dual efficacy of Silibinin where it inhibits progression of primary prostatic tumor and also shows protective efficacy against angiogenesis and late stage metastasis. These effects of Silibinin could have potential implications to improve the morbidity and survival in PCa patients. [Cancer Res 2008;68(16):6822–30]
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Silibinin suppresses in vivo growth of human prostate carcinoma pc 3 tumor xenograft
Carcinogenesis, 2007Co-Authors: Rana P Singh, Gagan Deep, Michael Pollak, Mariejose Blouin, Rajesh AgarwalAbstract:Chemoprevention is an upcoming approach to control cancer including prostate cancer (PCa). Here, we studied the efficacy and associated mechanisms of a chemopreventive agent Silibinin against ectopically growing and established advanced human prostate carcinoma PC-3 tumor xenografts in athymic nude mice. Dietary Silibinin (0.5%, w/w) did not show any adverse health effect in mice. In first protocol, Silibinin started 1 week prior to xenograft implantation and continued for 60 additional days, whereas in the second protocol, Silibinin treatment was started after 25 days of established tumors for 4, 8 and 16 days. Silibinin inhibited tumor growth rate in both protocols showing up to 35% (P = 0.010) and 18-56% (P = 0.002 to <0.001) decrease in tumor volume per mouse and 27% (P < 0.01) and 44% (P = 0.014) decrease in tumor weight per mouse, respectively. In first protocol, Silibinin decreased (P < 0.001) tumor cell proliferation and microvessel density but increased (P < 0.001) apoptosis. An increase in insulin-like growth factor-binding protein-3 (IGFBP-3) expression with a concomitant decrease in vascular endothelial growth factor (VEGF) expression was noted. Silibinin strongly increased phospho-extracellular signal-regulated kinase 1/2 (ERK1/2), Cip1/p21 and Kip1/p27 (cyclin-dependent kinase inhibitors) levels but moderately decreased Bcl-2 and survivin levels. In established tumors, similar biomarkers and molecular changes were observed due to Silibinin corresponding to its antitumor efficacy. These findings identified in vivo antitumor efficacy of Silibinin against PC-3 human PCa in both intervention protocols accompanied with its anti-proliferative, pro-apoptotic and anti-angiogenic activities. At molecular level, Silibinin increased IGFBP-3, Cip1/p21, Kip1/p27 levels and ERK1/2 activation and decreased Bcl-2, survivin and VEGF levels in tumors.
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Therapeutic efficacy of Silibinin on chemically-induced mouse lung tumors
Cancer Research, 2007Co-Authors: Lori D. Dwyer-nield, Rana P Singh, Alpna Tyagi, Alvin M. Malkinson, Rajesh AgarwalAbstract:AACR Annual Meeting-- Apr 14-18, 2007; Los Angeles, CA 4969 Silibinin, a flavanone from milk thistle, inhibits the growth of tumors in several chemically-induced rodent models, including mouse lung. We previously showed that dietary Silibinin markedly reduced growth, progression, and angiogenesis of urethane-induced lung tumors in A/J mice when fed to mice 2 weeks after carcinogen administration in a model of chemoprevention. To determine whether Silibinin could also act as a chemotherapeutic agent in this system, we examined the effects of Silibinin treatment on established mouse lung tumors. A/J mice, injected with urethane (1 mg/g body weight), were allowed to develop lung tumors for 33 wks. Tumors at this stage have characteristics of a malignant phenotype, i.e. they are invasive, exhibit nuclear dysmorphology, and are heterogeneous in appearance. Silibinin (or the vehicle control) was then administered by gavage (5 days/week, 742 mg/kg, a dose determined to be equivalent to the 1% wt./wt. dietary dose previously shown to be effective) for 10 wks. When mice were sacrificed and their lung tumor number and burden determined, those mice receiving Silibinin by gavage had 33% fewer tumors and 37% less tumor burden (pooled tumor wt/mouse) than mice receiving vehicle. Immunohistochemical analysis of fixed lungs showed that Silibinin-treated mice had 62% fewer PCNA positive cells compared to the vehicle-treated controls, indicating that Silibinin decreased tumor cell proliferation. Tumor microvessel density (as determined by counting CD31 positive cells in tumors), an indicator of neovasularization, decreased by 67% in Silibinin-treated mice over controls. There was 72% less COX-2 expression in tumors, an enzyme associated with lung neoplasia and angiogenesis, in Silibinin-treated mice. These results indicate that Silibinin is effective in slowing the growth of, and perhaps stimulating regression of, established mouse lung tumors. This implies that dietary Silibinin may be useful in preventing the neoplastic progression of early lesions in humans. This work was supported by CA 33497 and CA113876.
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Silibinin activates p53 caspase 2 pathway and causes caspase mediated cleavage of cip1 p21 in apoptosis induction in bladder transitional cell papilloma rt4 cells evidence for a regulatory loop between p53 and caspase 2
Carcinogenesis, 2006Co-Authors: Alpna Tyagi, Chapla Agarwal, Rana P Singh, Rajesh AgarwalAbstract:Silibinin, a natural flavonolignan, induces apoptosis in human bladder transitional-cell papilloma RT4 cells both in vitro and in vivo; however, mechanisms of such efficacy are not completely identified. Here, we studied the mechanisms involved in Silibinin-induced apoptosis of RT4 cells having intact p53. Silibinin increased p53 protein level together with its increased phosphorylation at serine 15, activated caspase cascade and caused Bid cleavage for apoptosis. Silibinin-caused p53 activation was mediated via ATM-Chk2 pathway, which in turn induced caspase 2-mediated apoptosis. Pifithrin-alpha, a p53 inhibitor, reversed Silibinin-induced caspase activation including caspase 2; however, caspase 2 inhibitor also reversed p53 phosphorylation suggesting a bidirectional regulation between them. Further, Silibinin caused a rapid translocation of p53 and Bid into mitochondria leading to increased permeabilization of mitochondrial membrane and cytochrome c release into the cytosol. JNK1/2 activation was observed as a connecting link for p53-mediated caspase 2 activation. Interestingly, Silibinin-induced apoptosis was mediated, in part, via Cip1/p21 cleavage by caspase, which was reversed by Cip1/p21 siRNA. Together, these results suggested the novel mechanisms for apoptosis induction by Silibinin involving p53-caspase 2 activation and caspase-mediated cleavage of Cip1/p21.
Chapla Agarwal - One of the best experts on this subject based on the ideXlab platform.
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role of p53 in Silibinin mediated inhibition of ultraviolet b radiation induced dna damage inflammation and skin carcinogenesis
Carcinogenesis, 2017Co-Authors: Cynthia M Rigby, Anil K. Jain, David J. Orlicky, Gagan Deep, Srirupa Roy, Ruth Guillermolagae, Deepanshi Dhar, Chapla AgarwalAbstract:Non-melanoma skin cancers (NMSC) are a growing problem given that solar ultraviolet B (UVB) radiation exposure is increasing most likely due to depletion of the atmospheric ozone layer and lack of adequate sun protection. Better preventive methods are urgently required to reduce UV-caused photodamage and NMSC incidence. Earlier, we have reported that Silibinin treatment activates p53 and reduces photodamage and NMSC, both in vitro and in vivo; but whether Silibinin exerts its protective effects primarily through p53 remains unknown. To address this question, we generated p53 heterozygous (p53+/-) and p53 knockout (p53-/-) mice on SKH-1 hairless mouse background, and assessed Silibinin efficacy in both short- and long-term UVB exposure experiments. In the chronic UVB-exposed skin tumorigenesis study, compared to p53+/+ mice, p53+/- mice developed skin tumors earlier and had higher tumor number, multiplicity and volume. Silibinin topical treatment significantly reduced the tumor number, multiplicity and volume in p53+/+ mice but Silibinin' protective efficacy was significantly compromised in p53+/- mice. Additionally, Silibinin treatment failed to inhibit precursor skin cancer lesions in p53-/- mice but improved the survival of the mice. In short-term studies, Silibinin application accelerated the removal of UVB-induced DNA damage in p53+/+ mice while its efficacy was partially compromised in p53-/- mice. Interestingly, Silibinin treatment also inhibited the UVB-induced inflammatory markers in skin tissue. These results further confirmed that absence of the p53 allele predisposes mice to photodamage and photocarcinogenesis, and established that Silibinin mediates its protection against UVB-induced photodamage, inflammation and photocarcinogenesis partly through p53 activation.
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Flavanone Silibinin treatment attenuates nitrogen mustard-induced toxic effects in mouse skin.
Toxicology and applied pharmacology, 2015Co-Authors: Anil K. Jain, Neera Tewari-singh, Swetha Inturi, Dileep Kumar, David J. Orlicky, Chapla Agarwal, Carl W. White, Rajesh AgarwalAbstract:Currently, there is no effective antidote to prevent skin injuries by sulfur mustard (SM) and nitrogen mustard (NM), which are vesicating agents with potential relevance to chemical warfare, terrorist attacks, or industrial/laboratory accidents. Our earlier report has demonstrated the therapeutic efficacy of Silibinin, a natural flavanone, in reversing monofunctional alkylating SM analog 2-chloroethyl ethyl sulfide-induced toxic effects in mouse skin. To translate this effect to a bifunctional alkylating vesicant, herein, efficacy studies were carried out with NM. Topical application of Silibinin (1 or 2 mg) 30 min after NM exposure on the dorsal skin of male SKH-1 hairless mice significantly decreased NM-induced toxic lesions at 24, 72 or 120 h post-exposure. Specifically, Silibinin treatment resulted in dose-dependent reduction of NM-induced increase in epidermal thickness, dead and denuded epidermis, parakeratosis and microvesication. Higher Silibinin dose also caused a 79% and 51%reversal in NM-induced increases in myeloperoxidase activity and COX-2 levels, respectively. Furthermore, Silibinin completely prevented NM-induced H2A.X phosphorylation, indicating reversal of DNA damage which could be an oxidative DNA damage as evidenced by high levels of 8-oxodG in NM-exposed mouse skin that was significantly reversed by Silibinin. Together, these findings suggest that attenuation of NM-induced skin injury by Silibinin is duemore » to its effects on the pathways associated with DNA damage, inflammation, vesication and oxidative stress. In conclusion, results presented here support the optimization of Silibinin as an effective treatment of skin injury by vesicants. - Highlights: • Silibinin treatment attenuated nitrogen mustard (NM)-induced skin injury. • Silibinin affects pathways associated with DNA damage, inflammation and vesication. • The efficacy of Silibinin could also be associated with oxidative stress. • These results support testing and optimization of Silibinin against SM-induced skin injury.« less
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Silibinin inhibits prostate cancer cells and rankl induced osteoclastogenesis by targeting nfatc1 nf κb and ap 1 activation in raw264 7 cells
Molecular Carcinogenesis, 2014Co-Authors: Chandagirikoppal V Kavitha, Rajesh Agarwal, Anil K. Jain, Chapla Agarwal, Gagan Deep, Subhash Chander GangarAbstract:Currently, there are limited therapeutic options against bone metastatic prostate cancer (PCA), which is primarily responsible for high mortality and morbidity in PCA patients. Enhanced osteoclastogenesis is an essential feature associated with metastatic PCA in the bone microenvironment. Silibinin, an effective chemopreventive agent, is in phase II clinical trials in PCA patients but its efficacy against PCA cells-induced osteoclastogenesis is largely unknown. Accordingly, here we examined Silibinin effect on PCA cells-induced osteoclastogenesis employing human PCA (PC3MM2, PC3 and C4-2B) and murine macrophage RAW264.7 cells. We also assessed Silibinin effect on receptor activator of nuclear factor B ligand (RANKL)-induced signaling associated with osteoclast differentiation in RAW264.7 cells. Further, we analyzed Silibinin effect on osteomimicry biomarkers in PCA cells. Results revealed that Silibinin (30–90 μM) inhibits PCA cells-induced osteoclast activity and differentiation in RAW264.7 cells via modulating expression of several cytokines (IGF-1, TGF-β, TNF-α, I-TAC, M-CSF, G-CSF, and GM-CSF etc.) that are important in osteoclastogenesis. Additionally, in RAW264.7 cells, Silibinin decreased the RANKL-induced expression and nuclear localization of NFATc1, which is considered the master regulator of osteoclastogenesis. Furthermore, Silibinin decreased the RANKL-induced DNA binding activity of NFATc1 and its regulators NF-κB and AP1, and the protein expression of osteoclast specific markers (TRAP, OSCAR and Cathepsin K). Importantly, Silibinin also decreased the expression of osteomimicry biomarkers (RANKL, Runx2, Osteocalcin and PTHrP) in cell culture (PC3 and C4-2B cells) and/or in PC3 tumors. Together, our findings showing that Silibinin inhibits PCA cells-induced osteoclastogenesis, suggest that Silibinin could be useful clinically against bone metastatic PCA.
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Silibinin activates p53 caspase 2 pathway and causes caspase mediated cleavage of cip1 p21 in apoptosis induction in bladder transitional cell papilloma rt4 cells evidence for a regulatory loop between p53 and caspase 2
Carcinogenesis, 2006Co-Authors: Alpna Tyagi, Chapla Agarwal, Rana P Singh, Rajesh AgarwalAbstract:Silibinin, a natural flavonolignan, induces apoptosis in human bladder transitional-cell papilloma RT4 cells both in vitro and in vivo; however, mechanisms of such efficacy are not completely identified. Here, we studied the mechanisms involved in Silibinin-induced apoptosis of RT4 cells having intact p53. Silibinin increased p53 protein level together with its increased phosphorylation at serine 15, activated caspase cascade and caused Bid cleavage for apoptosis. Silibinin-caused p53 activation was mediated via ATM-Chk2 pathway, which in turn induced caspase 2-mediated apoptosis. Pifithrin-alpha, a p53 inhibitor, reversed Silibinin-induced caspase activation including caspase 2; however, caspase 2 inhibitor also reversed p53 phosphorylation suggesting a bidirectional regulation between them. Further, Silibinin caused a rapid translocation of p53 and Bid into mitochondria leading to increased permeabilization of mitochondrial membrane and cytochrome c release into the cytosol. JNK1/2 activation was observed as a connecting link for p53-mediated caspase 2 activation. Interestingly, Silibinin-induced apoptosis was mediated, in part, via Cip1/p21 cleavage by caspase, which was reversed by Cip1/p21 siRNA. Together, these results suggested the novel mechanisms for apoptosis induction by Silibinin involving p53-caspase 2 activation and caspase-mediated cleavage of Cip1/p21.
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Silibinin Efficacy against Human Hepatocellular Carcinoma
Clinical cancer research : an official journal of the American Association for Cancer Research, 2005Co-Authors: Leyon Varghese, Rana P Singh, Chapla Agarwal, Alpana Tyagi, Rajesh AgarwalAbstract:Purpose: Hepatocellular carcinoma (HCC) is one of the most common recurrent malignancies, for which, currently, there is no effective therapy. Considering the antihepatotoxic activity of Silibinin, a widely used drug and supplement for various liver disorders, together with its strong preventive and anticancer efficacy against various epithelial cancers, we investigated the efficacy of silibin against human HCC cells. Experimental Design: Silibinin effects were examined on growth, cytotoxicity, apoptosis, and cell cycle progression in two different HCC cell lines, HepG2 (hepatitis B virus negative; p53 intact) and Hep3B (hepatitis B virus positive; p53 mutated). At molecular level, cell cycle effects of Silibinin were assessed by immunoblotting and in-bead kinase assays. Results: Silibinin strongly inhibited growth of both HepG2 and Hep3B cells with a relatively stronger cytotoxicity in Hep3B cells, which was associated with apoptosis induction. Silibinin also caused G 1 arrest in HepG2 and both G 1 and G 2 -M arrests in Hep3B cells. Mechanistic studies revealed that Silibinin induces Kip1/p27 but decreases cyclin D1, cyclin D3, cyclin E, cyclin-dependent kinase (CDK)-2, and CDK4 levels in both cell lines. In Hep3B cells, Silibinin also reduced the protein levels of G 2 -M regulators. Furthermore, Silibinin strongly inhibited CDK2, CDK4, and CDC2 kinase activity in these HCC cells. Conclusion: Together, these results for the first time identify the biological efficacy of Silibinin against HCC cells, suggesting the importance of conducting further investigations in preclinical HCC models, especially on in vivo efficacy, to support the clinical usefulness of Silibinin against hepatocellular carcinoma in addition to its known clinical efficacy as an antihepatotoxic agent.
Kazem Nejatikoshki - One of the best experts on this subject based on the ideXlab platform.
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inhibition of htert gene expression by Silibinin loaded plga peg fe3o4 in t47d breast cancer cell line
BioImpacts : BI, 2013Co-Authors: Zohreh Ebrahimnezhad, Nosratollah Zarghami, Manoutchehr Keyhani, Soumaye Amirsaadat, Abolfazl Akbarzadeh, Mohammad Rahmati, Zohreh Mohammad Taheri, Kazem NejatikoshkiAbstract:Introduction: Nowadays, using drug delivery is an essential method to improve cancer therapy through decreasing drug toxicity and increasing efficiency of treatment. Silibinin (C25H22O10), a polyphenolic flavonoid which is isolated from the milk thistle plant, has various applications in cancer therapy but it has hydrophobic structure with low water solubility and bioavailability. To increase the effect of Silibinin, Silibinin-loaded PLGA-PEG-Fe3O4 was prepared to determine the inhibitory effect of this nanodrug on Telomerase gene expression. Methods: The rate of Silibinin loaded into PLGA-PEG-Fe3O4 was measured. Then, the cytotoxic effect of Silibinin-loaded PLGA-PEG-Fe3O4 was determined by Methyl Thiazol Tetrazolium (MTT) assay. After that, inhibition of Telomerase gene expression was indicated through Real-time PCR. Results: Data analysis from MTT assay showed that Silibinin-loaded PLGA-PEG-Fe3O4 had dose dependent cytotoxic effect on T47D cell line. MTT assay showed no cytotoxic effect of free PLGA-PEG-Fe3O4 on T47D breast cancer cell line. Real Time PCR analysis showed that the level of telomerase gene expression more efficiently decreased with Silibinin-loaded PLGA-PEG-Fe3O4 than with free Silibinin alone. Conclusion: The present study indicates that this nanodrug causes down-regulation of Telomerase gene expression in cancer cells. Therefore, PLGA-PEG-Fe3O4 could be an appropriate carrier for hydrophobic agents such as Silibinin to improve their action in cancer therapy.