Cyclooxygenase-2/prostaglandin E2 pathway mediates icariside II induced apoptosis in human PC-3 prostate cancer cells

Bioinformatic analysis of hippocampal histopathology in Alzheimer's disease and the therapeutic effects of active components of traditional Chinese medicine

Background and aim

Pathological changes in the central nervous system (CNS) begin before the clinical symptoms of Alzheimer's Disease (AD) manifest, with the hippocampus being one of the first affected structures. Current treatments fail to alter AD progression. Traditional Chinese medicine (TCM) has shown potential in improving AD pathology through multi-target mechanisms. This study investigates pathological changes in AD hippocampal tissue and explores TCM active components that may alleviate these changes.

Methods

GSE5281 and GSE173955 datasets were downloaded from GEO and normalized to identify differentially expressed genes (DEGs). Key functional modules and hub genes were analyzed using Cytoscape and R. Active TCM components were identified from literature and the Pharmacopoeia of the People's Republic of China. Enrichment analyses were performed on target genes overlapping with DEGs.

Result

From the datasets, 76 upregulated and 363 downregulated genes were identified. Hub genes included SLAMF, CD34, ELN (upregulated) and ATP5F1B, VDAC1, VDAC2, HSPA8, ATP5F1C, PDHA1, UBB, SNCA, YWHAZ, PGK1 (downregulated). Literature review identified 33 active components from 23 herbal medicines. Target gene enrichment and analysis were performed for six components: dihydroartemisinin, berberine, naringenin, calycosin, echinacoside, and icariside II.

Conclusion

Mitochondrial to synaptic vesicle dysfunction pathways were enriched in downregulated genes. Despite downregulation, UBB and SNCA proteins accumulate in AD brains. TCM studies suggest curcumin and echinacoside may improve hippocampal pathology and cognitive impairment in AD. Further investigation into their mechanisms is needed.

Cancer-Related Therapeutic Potential of Epimedium and Its Extracts

Epimedium is a Chinese herb known as "yin and yang fire," first mentioned in the Compendium of Materia Medica. Many of the proprietary Chinese medicines used in clinical practice contain Epimedium as an ingredient, and its main active constituents include icariin, icaritin, and icariside II, among others. In addition to its traditional use in treating fatigue and sexual problems, modern research has confirmed that the main bioactive compounds in Epimedium have pharmacological effects such as antidepressant, antibacterial, antiviral, antioxidant, and anti-inflammatory properties, as well as inhibiting bone destruction, promoting bone growth, improving immune regulation and protecting the cardio-cerebral vascular system. With the continuous development of extraction and purification techniques, the development and use of bioactive compounds in Epimedium have significantly progressed, and the anticancer effect has received widespread attention. Since natural herbs have few side effects on the human body and do not easily develop drug resistance, they have long been the direction of research in cancer treatment. This review summarizes the latest research on the anticancer effects of Epimedium and its extracts, describes the bioactive compounds, pharmacological efficacy, and antitumor mechanism of Epimedium, and gives a new view on the administration and development of Epimedium.

Icariin‑curcumol promotes ferroptosis in prostate cancer cells through Nrf2/HO‑1 signaling

Ferroptosis is a form of regulatory cell death that relies on iron and reactive oxygen species (ROS) to inhibit tumors. The present study aimed to investigate whether icariin-curcumol could be a novel ferroptosis inducer in tumor inhibition. Various concentrations of icariin-curcumol were used to stimulate prostate cell lines (RWPE-2, PC-3, VCAP and DU145). Small interfering negative control (si-NC) and si-nuclear factor erythroid 2-related factor 2 (Nrf2) were used to transfect DU145 cells. Cell viability was determined by using cell counting kit-8. Ferroptosis-related factor levels were analyzed using western blotting and reverse transcription-quantitative PCR. Enzyme-linked immunosorbent assays were used to assess the ferrous (Fe2+), glutathione and malondialdehyde (MDA) content. The ROS fluorescence intensity was assessed using flow cytometry. DU145 cells were most sensitive to icariin-curcumol concentration. The Fe2+ content, ROS fluorescence intensity and MDA level gradually increased, while solute carrier family 7 member 11 (SLC7A11) level, glutathione peroxidase 4 (GPX4) level, GSH content, Nrf2 and heme oxygenase-1 (HO-1) decreased with icariin-curcumol in a dose-dependent manner. After si-Nrf2 was transfected, the cell proliferation ability, SLC7A11 and GPX4 levels declined compared with the si-NC group. In contrast to the control group, the icariin + curcumol group showed reductions in Nrf2 and HO-1 levels, cell proliferation, SLC7A11 and GPX4 levels, with an increase in Fe2+ content and ROS fluorescence intensity. Overexpression of Nrf2 reversed the regulation observed in the icariin + curcumol group. Icariin-curcumol induced ferroptosis in PCa cells, mechanistically by inhibiting the Nrf2/HO-1 signaling pathway. Icariin-curcumol could be used as a new type of ferroptosis inducer to treat PCa effectively.

A systematic review of traditional uses, phytochemistry, pharmacology and toxicity of Epimedium koreanum Nakai

ETHNOPHARMACOLOGICAL RELEVANCE

Epimedium koreanum Nakai (E. koreanum), a member of the genus Epimedium in the family Berberidaceae, is a well-known and well-liked traditional herb used as a "kidney tonic". For thousands of years, it has been utilized for renal yang deficiency, impotence, spermatorrhea, impotence, weakness of tendons and bones, rheumatic paralysis and discomfort, numbness, and constriction.

AIM OF THE STUDY

The paper aims to comprehensively in-depth, and methodically review the most recent research on the traditional uses, phytochemistry, pharmacology, and toxicity of E. koreanum.

MATERIALS AND METHODS

Scientific databases including Web of Science, PubMed, Google Scholar, Elsevier, Springer, ScienceDirect, Baidu Scholar, and CNKI and medicine books in China were searched for relevant information on E. koreanum.

RESULTS

In traditional uses, E. koreanum is frequently used to treat various diseases like erectile dysfunction, infertility, rheumatoid arthritis, osteoporosis, asthma, kidney-yang deficiency syndrome, etc. To date, more than 379 compounds have been discovered from various parts of E. koreanum, including flavonoids, lignans, organic acids, terpenoids, hydrocarbons, dihydrophenanthrene derivatives, alkaloids, and others. Research has revealed that the compounds and crude extracts have a wide range of pharmacological effects on the reproductive, cardiovascular, and nervous systems, as well as anti-osteoporosis, anti-tumor, antioxidant, anti-inflammatory, immunomodulatory, hepatoprotective, and antiviral properties. Besides, the crude extracts show potential hepatotoxicity.

CONCLUSION

Based on recent domestic and international research investigations, E. koreanum contains a wealth of chemical components with pronounced pharmacological activities. Its traditional uses are numerous, and the majority of these traditional uses have been supported by contemporary pharmacological investigations. Crude extracts, on the other hand, can result in hepatotoxicity. Therefore, additional in vivo and in vitro experimental research on the pharmacology and toxicology of E. koreanum are required in the future to assess its safety and efficacy. This will give a firmer scientific foundation for its safe application and the development of new drugs in the future.

Inflammatory signaling pathways in the treatment of Alzheimer's disease with inhibitors, natural products and metabolites (Review)

The intricate nature of Alzheimer's disease (AD) pathogenesis poses a persistent obstacle to drug development. In recent times, neuroinflammation has emerged as a crucial pathogenic mechanism of AD, and the targeting of inflammation has become a viable approach for the prevention and management of AD. The present study conducted a comprehensive review of the literature between October 2012 and October 2022, identifying a total of 96 references, encompassing 91 distinct pharmaceuticals that have been investigated for their potential impact on AD by inhibiting neuroinflammation. Research has shown that pharmaceuticals have the potential to ameliorate AD by reducing neuroinflammation mainly through regulating inflammatory signaling pathways such as NF‑κB, MAPK, NLRP3, PPARs, STAT3, CREB, PI3K/Akt, Nrf2 and their respective signaling pathways. Among them, tanshinone IIA has been extensively studied for its anti‑inflammatory effects, which have shown significant pharmacological properties and can be applied clinically. Thus, it may hold promise as an effective drug for the treatment of AD. The present review elucidated the inflammatory signaling pathways of pharmaceuticals that have been investigated for their therapeutic efficacy in AD and elucidates their underlying mechanisms. This underscores the auspicious potential of pharmaceuticals in ameliorating AD by impeding neuroinflammation.

Icariin-Curcumol promotes docetaxel sensitivity in prostate cancer through modulation of the PI3K-Akt signaling pathway and the Warburg effect

BACKGROUND

Docetaxel (DTX) resistance reduces therapeutic efficacy in prostate cancer (PCa). Accumulating reports support the role of phytochemicals in the reversal of DTX resistance. This study aimed to determine whether Epimedium brevicornu and Curcuma zedoaria extracts (ECe), specially icariin-curcumol, attenuates DTX resistance and explore their potential mechanisms.

METHODS

Regulatory pathways were predicted between ECe active ingredients and PCa using network pharmacology. DTX-resistant cell LNCaP/R were established based on DTX-sensitive LNCaP, and xenograft models were further established. Active ingredients in ECe by HLPC-MS were identified. The binding of icariin and curcumol to the target was analyzed by molecular docking. Biochemical experiments were applied to determine the possible mechanisms by which Icariin-Curcumol regulates DTX sensitivity.

RESULTS

Akt1 and the PI3K-Akt signaling pathway were predicted as the primary functional target between drug and PCa. ECe and DTX inhibited xenograft tumor growth, inflammation, cell viability and promoted apoptosis. Icariin and curcumol were detected in ECe, and icariin and curcumol docked with Akt1. ECe, Icariin-Curcumol and DTX downregulated AR, PSA, PI3K, Akt1, mTOR, and HIF-1ɑ. Moreover, ECe, Icariin-Curcumol and DTX increased glucose and PDH, decreased lactic acid, ATP and LDH, and downregulated c-Myc, hnRNPs, VEGF, PFK1, and PKM2. Notably, the anti-PCa effect of DTX was attenuated compared to ECe or Icariin-Curcumol in the LNCaP/R model. The combined effect of Icariin-Curcumol and DTX was superior to that of DTX.

CONCLUSION

Our data support that Icariin-Curcumol reverses DTX resistance by inhibiting the PI3K-Akt signaling and the Warburg effect, providing new ideas for improving therapeutic measures for PCa.

Multidisciplinary strategies to enhance therapeutic effects of flavonoids from Epimedii Folium: Integration of herbal medicine, enzyme engineering, and nanotechnology

Flavonoids such as baohuoside I and icaritin are the major active compounds in Epimedii Folium (EF) and possess excellent therapeutic effects on various diseases. Encouragingly, in 2022, icaritin soft capsules were approved to reach the market for the treatment of hepatocellular carcinoma (HCC) by National Medical Products Administration (NMPA) of China. Moreover, recent studies demonstrate that icaritin can serve as immune-modulating agent to exert anti-tumor effects. Nonetheless, both production efficiency and clinical applications of epimedium flavonoids have been restrained because of their low content, poor bioavailability, and unfavorable in vivo delivery efficiency. Recently, various strategies, including enzyme engineering and nanotechnology, have been developed to increase productivity and activity, improve delivery efficiency, and enhance therapeutic effects of epimedium flavonoids. In this review, the structure-activity relationship of epimedium flavonoids is described. Then, enzymatic engineering strategies for increasing the productivity of highly active baohuoside I and icaritin are discussed. The nanomedicines for overcoming in vivo delivery barriers and improving therapeutic effects of various diseases are summarized. Finally, the challenges and an outlook on clinical translation of epimedium flavonoids are proposed.

Icariside II potentiates the anti-PD-1 antitumor effect by reducing chemotactic infiltration of myeloid-derived suppressor cells into the tumor microenvironment via ROS-mediated inactivation of the SRC/ERK/STAT3 signaling pathways

BACKGROUND

Immune checkpoint blockade agents, such as anti-PD-1 antibodies, show promising antitumor efficacy but only a limited response in patients with non-small cell lung cancer (NSCLC). Icariside II (IS), a metabolite of Herba Epimedii, is a COX-2 and EGFR inhibitor that can enhance the anti-PD-1 effect. This study aimed to evaluate the antitumor effect of IS in combination with anti-PD-1 and explore the underlying mechanism.

METHODS

Tumor growth was assessed in Lewis Lung Cancer (LLC) tumor-bearing mice in seven groups (control, IS 20 mg/kg, IS 40 mg/kg, anti-PD-1, IS 20 mg/kg+anti-PD-1, IS 40 mg/kg+anti-PD-1, ERK inhibitor+anti-PD-1). Tumor-infiltrating immune cells were measured by flow cytometry. The mechanisms were explored by tumor RNA-seq and validated in LLC cells through molecular biological experiments using qRT‒PCR, ELISA, and western blotting.

RESULTS

Animal experiments showed that IS in combination with anti-PD-1 further inhibited tumor growth and remarkably reduced the infiltration of myeloid-derived suppressor cells (MDSCs) into the tumor compared with anti-PD-1 monotherapy. RNA-seq and in vitro experiments showed that IS suppressed the chemotactic migration of MDSCs by downregulating the expression of CXC chemokine ligands 2 (CXCL2) and CXCL3. Moreover, IS promoted reactive oxygen species (ROS) generation and inhibited the activation of SRC/ERK/STAT3 in LLC cells, which are upstream signaling pathways of these chemokines.

CONCLUSION

IS potentiates the anti-PD-1 anti-tumor effect by reducing chemotactic infiltration of the myeloid-derived suppressor cell into the tumor microenvironment, via ROS-mediated inactivation of SRC/ERK/STAT3 signaling pathways.

Effects of icariin and curcumol on autophagy, ferroptosis, and lipid metabolism based on miR-7/m-TOR/SREBP1 pathway on prostate cancer

This study aimed to investigate the effects and underlying molecular mechanisms of icariin (ICA) and curcumol on autophagy, ferroptosis, and lipid metabolism in prostate cancer (PCa), in vitro and in vivo. Normal prostate epithelial cells RWPE-1 and PCa cell lines DU145 and PC-3 were treated with ICA and curcumol. Ferrostatin-1 (Fer-1) or 3-MA was added to treat DU145 and PC-3 cells. In addition, we knocked down miR-7. The mechanism of ICA and curcumol in PCa cells after the knockdown of miR-7 was verified by in vitro nude mice tumorigenesis experiments. ICA and curcumol had no significant effect on the viability of RWPE-1 cells, but there was a significant difference between DU145 and PC-3 cells. After treatment with ICA and curcumol, the proliferation of PCa cells was inhibited, apoptosis, reactive oxygen species (ROS) levels, and miR-7 expression were increased. The combined treatment of ICA and curcumol had a more significant effect. ICA and curcumol treatment induced autophagy and ferroptosis in PCa cells, and si-miR-7 reversed the effects of ICA and curcumol on autophagy and ferroptosis. MiR-7 targeted mTOR and regulated the expression of the mTOR/SREBP1 pathway in PCa cells. ICA and curcumol may affect the lipid metabolism of PCa cells by affecting SREBP1. In addition, the effects and mechanisms of ICA and curcumol on autophagy, ferroptosis, and lipid metabolism in PCa cells were verified in vivo. ICA and curcumol synergistically regulated the miR-7/mTOR/SREBP1 pathway to induce autophagy and ferroptosis in PCa cells and affected lipid metabolism.

Icariside I - A novel inhibitor of the kynurenine-AhR pathway with potential for cancer therapy by blocking tumor immune escape

BACKGROUND

Although therapeutic antibodies against immune checkpoints such as PD-1/PD-L1 have achieved unprecedented success in clinical tumor patients, there are still many patients who are ineffective or have limited responses to immune checkpoint blockade (ICB). Discovery of novel strategies for cancer immunotherapy including natural small molecules is needed.

METHODS

Owing to its extremely low content in Epimedium genus, we firstly constructed a microbial cell factory to enzymatically biosynthesize icariside I, a natural flavonoid monosaccharide from Herbal Epimedium. Using a combination of targeted MS-based metabolomics, flow cytometric analysis, and biological assays, the therapeutic potentials of icariside I were subsequently investigated in vivo and in vitro.

RESULTS

We find that icariside I markedly downregulates a series of intermediate metabolites such as kynurenine, kynurenic acid and xanthurenic acid and corresponding key enzymes involved in kynurenine-AhR pathway in both tumor cells and tumor-bearing mice. In vivo, oral administration of icariside I downregulates SLC7A8 and PAT4 transporters and AhR, thus inhibiting nuclear PD-1 in CTLs. Moreover, icariside I significantly upregulates CD8 + T cells in both peripheral blood and tumor tissues of tumor-bearing mice. Consequently, interferon-γ (IFN-γ) secreted by CD8 + T cells suppresses tumor growth through activation of JAK1-STAT1 signaling, thus inducing tumor cell apoptosis.

CONCLUSIONS

These results suggest that icariside I could be an effective small molecule drug for tumor immunotherapy by blocking kynurenine-AhR pathway and tumor immune escape.

Bioavailability Improvement Strategies for Icariin and Its Derivates: A Review

In recent years, there has been considerable interest in icariin (ICA) and its derivates, icariside II (ICS) and icaritin (ICT), due to their wide range of potential applications in preventing cancer, cardiovascular disease, osteoporosis, delaying the effects of Alzheimer’s disease, treating erectile dysfunction, etc. However, their poor water solubility and membrane permeability, resulting in low bioavailability, dampens their potential beneficial effects. In this regard, several strategies have been developed, such as pharmaceutical technologies, structural transformations, and absorption enhancers. All these strategies manage to improve the bioavailability of the above-mentioned flavonoids, thus increasing their concentration in the desired places. This paper focuses on gathering the latest knowledge on strategies to improve bioavailability for enhancing the efficacy of icariin, icariside II, and icaritin. We conclude that there is an opportunity for many further improvements in this field. To the best of our knowledge, no such review articles scoping the bioavailability improvement of icariin and its derivates have been published to date. Therefore, this paper can be a good starting point for all those who want to deepen their understanding of the field.

Microbiome analysis combined with targeted metabolomics reveal immunological anti-tumor activity of icariside I in a melanoma mouse model

Recent studies report that the gut microbiome can enhance systemic and antitumor immunity by modulating responses to antibody immunotherapy in melanoma patients. In this study, we found that icariside I, a novel anti-cancer agent isolated from Epimedium, significantly inhibited B16F10 melanoma growth in vivo through regulation of gut microbiota and host immunity. Oral administration of icariside I improved the microbiota community structure with marked restoration of Lactobacillus spp. and Bifidobacterium spp. abundance in the cecal contents of tumor-bearing mice. We also found that icariside I improves the levels of microbiota-derived metabolites such as short-chain fatty acids (SCFAs) and indole derivatives, consequently promoting repair of the intestinal barrier and reducing systemic inflammation of tumor-bearing mice. Icariside I exhibited strong immunological anti-tumor activity, directly manifested by up-regulation of multiple lymphocyte subsets including CD4+ and CD8+ T cells or NK and NKT cells in peripheral blood of tumor-bearing mice. Collectively, these results suggest that icariside I, via its microbiome remodeling and host immune regulation properties, may be developed as an anticancer drug.

Icariside II: Anticancer Potential and Molecular Targets in Solid Cancers

Icariside II, an active flavonoid, is extracted from the traditional Chinese medicinal herb Epimedii. It possesses multiple biological and pharmacological properties, including anti-inflammatory, anticancer, and anti-osteoporotic properties. In recent years, apoptosis has become the hot spot in anticancer therapies. Icariside II exerts positive effects on inducing apoptosis and inhibiting proliferation in various cancers. The antitumorigenic activity of Icariside II was also proven through cell cycle arrest, triggering autophagy, reducing cellular metabolism, and inhibiting cancer metastasis and tumor-associated angiogenesis. Additionally, Icariside II, as a natural product, contributed to a synergistic effect alongside chemotherapeutic drugs. Due to its poor aqueous solubility and permeability, more strategies were developed to improve its therapeutic effects. This review aimed to summarize the chemopreventive properties of Icariside II in solid tumors and reveal its underlying molecular mechanisms.

Icariin-induced inhibition of SIRT6/NF-κB triggers redox mediated apoptosis and enhances anti-tumor immunity in triple-negative breast cancer

Abnormal activation of the nuclear factor-kappa B (NF-κB) signaling pathway is closely implicated in triple-negative breast cancer growth, metastasis, and tumor immune escape. In this study, the anti-cancer effects of icariin, a natural flavonol glycoside, toward breast cancer cells and the underlying mechanisms were investigated. This investigation showed that icariin selectively inhibited proliferation and triggered apoptosis in breast cancer cells in a concentration- and time-dependent manner, but exhibited little cytotoxicity in normal breast cells. Moreover, icariin induced cell apoptosis via a mitochondria-mediated pathway, as indicated by the upregulated ratio of Bax/Bcl-2 and reactive oxygen species induction. Importantly, icariin impaired the activation of the NF-κB/EMT pathway, as evidenced by upregulation of SIRT6, resulting in inhibition of migration and invasion of breast cancer cells. Additionally, oss-128167, an inhibitor of SIRT6, dramatically attenuated anti-migration and anti-invasion effects of icariin. Transcriptomic analysis verified that impairment of NF-κB led to the selective function of icariin in breast cancer cells. Notably, icariin exhibited a significant tumor growth inhibition and anti-pulmonary metastasis effect in a tumor mouse model of MDA-MB-231 and 4T1 cells by regulating the tumor immunosuppressive microenvironment. Together, these results showed that icariin could effectively trigger apoptosis and inhibit the migration of breast cancer cells via the SIRT6/NF-κB signaling pathway, suggesting that icariin might serve as a potential candidate drug for the treatment of breast cancer.

Herbal extracts as antiviral agents

Phytotherapy, or herbalism, is defined as the usage of plants or herbs as medication to treat or prevent diseases in human and animals. The usage is gaining more attention among medical practitioners as well as large-scale livestock producers. A number of reports have shown the positive effects of herbal extracts as an antiviral agent used in animal feed or as a prophylaxis and remedy. Besides being a cheaper and safer alternative, the use of herbs may reduce the incidence of drug resistance and may modulate the immune system in preventing viral-related diseases. In this chapter, the antiviral effects of several herbs and their extracts against viruses in terms of the mechanism of action in targeting viral replication steps, the effects in the host and the application in animals will be discussed. The information given may aid in improving the health and increase the production of animals.

Icariside II inhibits tumorigenesis via inhibiting AKT/Cyclin E/ CDK 2 pathway and activating mitochondria-dependent pathway

Cervical cancer contributes largely in women cancer-related mortality. Herein, Icariside II, a flavonoid extracted from edible and pharmaceutical plant Epimedium brevicornum Maxim, exhibited significant anticancer activity on cervical cancer. At first, it was observed that Icariside II inhibited Hela cell proliferation at IC₅₀ (9.2 μM) and the growth of Hela-originated xenografts in BALB/c nude mice. Next, we studied the underlying mechanisms of Icariside II from the aspects of cell growth and cell death. As for cell growth, Icariside II arrested cell cycle at G0/G1 phase through AKT/Cyclin E/CDK 2 from transcriptional and translational levels. As for cell death, Flow Cytometry and Immunofluorescence showed that Icariside II promoted cell death in a dose-dependet manner. And, Icariside II turned to activate the mitochondria-dependent pathway Caspase 9/Caspase 3 much more significantly than death receptor pathway Caspase 8/Caspase 3. Taken together, Icariside II presented anticancer effect on cervical cancer both in vitro and in vivo. Our study provides the evidence that Icariside II can be used as a suitable novel agent in cervical cancer treatment.

The association between nonsteroidal anti-inflammatory drugs and skin cancer: Different responses in American and European populations

OBJECTIVE

To conduct a comprehensive systematic meta-analysis investigating the association of nonsteroidal anti-inflammatory drugs (NSAIDs) and their subtypes with skin cancer (SC) and its subclasses (basal cell carcinoma BCC; squamous cell carcinoma SCC; melanoma; nonmelanoma skin cancer NMSC) in general, American and European populations.

METHODS

PubMed, Embase, the Cochrane Library, the China National Knowledge Infrastructure and ClinicalTrials.gov were searched up to 24 February 2019. Pooled effect sizes and 95% confidence intervals were used to estimate associations.

RESULTS

Results based on 26 original studies including 223,619 cases and 1,398,507 controls showed both NSAIDs and nonselective Cyclooxygenase (COX) inhibitors to be statistically significantly associated with a reduced risk of SC, BCC, SCC and NMSC but not with melanoma. Conversely, no association was observed between selective Cyclooxygenase 2 (COX-2) inhibitors and SC or its subclasses. Further subgroup analysis showed that the results analyzed for American populations were almost the same as those for the general population. For European populations, neither NSAIDs nor its subtypes correlated significantly with susceptibility to SC or its subclasses.

CONCLUSIONS

The use of NSAIDs might reduce the risk of SC, but many factors including study population, drug subtype, and disease subclass affect the significance of the association.

Optimization of the process for purifying icariin from Herba Epimedii by macroporous resin and the regulatory role of icariin in the tumor immune microenvironment

Pancreatic cancer is a digestive tract malignancy that poses a serious threat to human health. Compounds derived from traditional Chinese medicines have been an important source of anticancer drugs and adjuvant agents to regulate the tumor immune microenvironment in patients with pancreatic cancer. In this study, icariin was purified from Herba Epimedii using macropores, and its bioactivity against pancreatic cancer was also investigated. We found that icariin has direct inhibitory and immunomodulatory effects on tumor cells. In vitro experiments showed that icariin can inhibit the migration and proliferation of Panc02 pancreatic cancer cells and induce apoptosis. Our in vivo experiments show that icariin inhibits the development of mouse pancreatic cancer by inhibiting tumor-infiltrating M2 macrophages and polymorphonuclear myeloid-derived suppressor cells (MDSCs) (PMN-MDSCs). In addition, icariin inhibits the polarization of RAW 264.7 cells into M2 macrophages by inhibiting the expression of ARG1 and MRC1 and downregulating the IL4-STAT6 signaling pathway. In conclusion, the inhibitory effect of icariin on pancreatic cancer can not only directly affect tumor cells but also inhibit tumor development by regulating the tumor immune microenvironment.

Baohuoside-I suppresses cell proliferation and migration by up-regulating miR-144 in melanoma

CONTEXT

Baohuoside-I was reported to induce apoptosis in non-small-cell lung cancer and inhibit the growth of multiple myeloma cells. The antitumour potential of baohuoside-I has not been demonstrated in melanoma yet.

OBJECTIVE

To investigate the potential antitumour activity of baohuoside-I against melanoma and elucidate its underlying molecular mechanism.

MATERIALS AND METHODS

Cell viability was evaluated by MTT assay. The malignant invasion capacity was measured with trans-well assay. The relative expression change of microRNAs was profiled with microarray. TargetScan was utilized for prediction of target gene of miR-144. Regulatory effect of miR-144 on SMAD1 was determined by dual luciferase reporter assay. Endogenous SMAD1 protein in response to ectopic expression of miR-144 was determined by immunoblotting. Xenograft mice were employed to evaluate antitumour potential of baohuoside-I (25 mg/kg by tail intravenous injection every two days) in vivo.

RESULTS

Baohuoside-I significantly inhibited proliferation (45 ± 4% reduction in M14 and 35 ± 3% reduction in MV3 at 24 h) and migration (70 ± 4% reduction in M14 and 72 ± 3% reduction in MV3) in melanoma cells. Mechanistically, baohuoside-I up-regulated miR-144 expression levels (3 ± 0.2-fold). Silence of miR-144 reversed the inhibition of baohuoside-I in melanoma. We have identified that SMAD1 was the novel target of miR-144. Moreover, baohuoside-I suppressed melanoma in vivo (52 ± 8% reduction in xenograft tumour size at day 20).

CONCLUSIONS

Our data suggested significant antitumour potential of baohuoside-I against melanoma both in vitro and in vivo, which warrants further laboratory investigation and clinical trial.

Icariside II activates EGFR-Akt-Nrf2 signaling and protects osteoblasts from dexamethasone

The potential effect of icariside II on dexamethasone-induced osteoblast cell damages was evaluated here. In MC3T3-E1 osteoblastic cells and the primary murine osteoblasts, co-treatment with icariside II dramatically attenuated dexamethasone- induced cell death and apoptosis. Icariside II activated Akt signaling, which is required for its actions in osteoblasts. Akt inhibitors (LY294002, perifosine and MK-2206) almost abolished icariside II-induced osteoblast cytoprotection against dexamethasone. Further studies showed that icariside II activated Nrf2 signaling, downstream of Akt, to inhibit dexamethasone-induced reactive oxygen species (ROS) production in MC3T3-E1 cells and primary osteoblasts. On the other hand, Nrf2 shRNA knockdown inhibited icariside II-induced anti-dexamethasone cytoprotection in MC3T3-E1 cells. Finally, we showed that icariside II induced heparin-binding EGF (HB-EGF) production and EGFR trans-activation in MC3T3-E1 cells. EGFR inhibition, via anti-HB-EGF antibody, EGFR inhibitor AG1478 or EGFR shRNA knockdown, almost blocked icariside II-induced Akt-Nrf2 activation in MC3T3-E1 cells. Collectively, we conclude that icariside II activates EGFR-Akt-Nrf2 signaling and protects osteoblasts from dexamethasone. Icariside II might have translational value for the treatment of dexamethasone-associated osteoporosis/osteonecrosis.

Prostaglandin E2 receptor EP4 is involved in the cell growth and invasion of prostate cancer via the cAMP‑PKA/PI3K‑Akt signaling pathway

Prostate cancer (PCa) is one of the most prevalent diagnosed malignancies globally. Previous studies have demonstrated that prostaglandin E2 (PGE2) is closely associated with the tumorigenesis and progression of PCa. However, the underlying molecular mechanisms remain unclear and require further investigation. Matrix metalloproteinases (MMPs), receptor activator of nuclear factor‑κB ligand (RANKL) and runt‑related transcription factor 2 (RUNX2), which are involved in cell growth and bone metastasis, are frequently activated or overexpressed in various types of cancer, including PCa. The present study was designed to investigate the associations between PGE2 and the PGE2 receptor EP4, and MMPs, RANKL and RUNX2 in PCa, and to define their roles in PCa cell proliferation and invasion in addition to understanding the molecular mechanisms. The results of western blotting and reverse transcription‑quantitative polymerase chain reaction demonstrated that the protein and the mRNA expression levels of MMP‑2, MMP‑9, RANKL and RUNX2 in PC‑3 cells were significantly upregulated by treatment with PGE2, respectively, and knockdown of these proteins blocked PGE2‑induced cell proliferation and invasion in PC‑3 cells, as determined by Cell Counting Kit‑8 and Matrigel invasion assays, respectively. The effect of PGE2 on the protein and mRNA expression levels was primarily regulated via the EP4 receptor. EP4 receptor signaling activates the cyclic (c)AMP‑protein kinase A (PKA) signaling pathway, and forskolin, an activator of adenylate cyclase (AC), exhibited similar effects to an EP4 receptor agonist on the protein expression, while SQ22536, an inhibitor of AC, inhibited the protein expression. These results confirmed that the AC/cAMP pathway may be involved in EP4 receptor‑mediated upregulation of protein expression. By using a specific inhibitor of PKA, it was also demonstrated that cAMP/PKA was also involved in the EP4 receptor‑mediated upregulation of protein expression. In addition to the signaling pathway involving PKA, the EP4 receptor also exerts activities through activation of Akt kinase. The results in the present study confirmed the hypothesis that EP4 receptor‑mediated protein expression in PCa cells that were pretreated with a specific inhibitor of phosphatidylinositol 3‑kinase (PI3K) was significantly inhibited. In conclusion, the results of the present study indicate that PGE2 significantly upregulated the mRNA and protein expression levels of the MMP‑2, MMP‑9, RANKL and RUNX2, and the EP4 receptor was involved in the cell proliferation and invasion of PCa via the cAMP‑PKA/PI3K‑Akt signaling pathway. These results may provide novel insight into potential therapeutic strategies for the prevention and treatment of PCa.

Effects of icariside II ameliorates diabetic cardiomyopathy in streptozotocin-induced diabetic rats by activating Akt/NOS/NF-κB signaling

Icariside II is a flavonoid extracted from Epimedium that has antioxidant, anti‑inflammatory and antiapoptotic effects. The aim of the present study was to evaluate the effects icariside II on diabetic cardiomyopathy in streptozotocin-induced diabetic rats. Icariside II treatment improved body weight, heart/body weight ratio and fasting blood glucose in diabetic model rats. Icariside II was demonstrated to reduce the expression levels of creatine kinase and lactate dehydrogenase in serum, and to lower cardiac oxidative stress, inflammation and apoptosis levels in diabetic rats. Icariside II treatment induced phosphoinositide 3‑kinase and phosphorylated‑Akt expression, and suppressed inducible nitric oxide synthase (iNOS) and nuclear factor (NF)‑κB protein expression in diabetic rat. Results from the present study suggested that treatment with icariside II improved diabetic cardiomyopathy in streptozotocin‑induced diabetic rats by activating the Akt/NOS/NF‑κB pathway.

Prenylated flavonoids and dihydrophenanthrenes from the leaves of Epimedium brevicornu and their cytotoxicity against HepG2 cells

Phytochemical study on the leaves of Epimedium brevicornu finally led to the isolation of four prenylated flavonoids (1-4) and three dihydrophenanthrenes (5-7), of which 1, 2, 5 and 7 were new compounds. The structures of these compounds were established mainly by spectroscopic techniques, including NMR spectroscopy and mass spectrometry. These isolates exhibited the cytotoxic activities against HepG2 cells with the IC₅₀ values of 32.8-87.3 μM.

Multidrug-resistant cancer cells and cancer stem cells hijack cellular systems to circumvent systemic therapies, can natural products reverse this?

Chemotherapy is one of the most effective and broadly used approaches for cancer management and many modern regimes can eliminate the bulk of the cancer cells. However, recurrence and metastasis still remain a major obstacle leading to the failure of systemic cancer treatments. Therefore, to improve the long-term eradication of cancer, the cellular and molecular pathways that provide targets which play crucial roles in drug resistance should be identified and characterised. Multidrug resistance (MDR) and the existence of tumor-initiating cells, also referred to as cancer stem cells (CSCs), are two major contributors to the failure of chemotherapy. MDR describes cancer cells that become resistant to structurally and functionally unrelated anti-cancer agents. CSCs are a small population of cells within cancer cells with the capacity of self-renewal, tumor metastasis, and cell differentiation. CSCs are also believed to be associated with chemoresistance. Thus, MDR and CSCs are the greatest challenges for cancer chemotherapy. A significant effort has been made to identify agents that specifically target MDR cells and CSCs. Consequently, some agents derived from nature have been developed with a view that they may overcome MDR and/or target CSCs. In this review, natural products-targeting MDR cancer cells and CSCs are summarized and clustered by their targets in different signaling pathways.

Icariside II, a Broad-Spectrum Anti-cancer Agent, Reverses Beta-Amyloid-Induced Cognitive Impairment through Reducing Inflammation and Apoptosis in Rats

Beta-amyloid (Aβ) deposition, associated neuronal apoptosis and neuroinflammation are considered as the important factors which lead to cognitive deficits in Alzheimer's disease (AD). Icariside II (ICS II), an active flavonoid compound derived from Epimedium brevicornum Maxim, has been extensively used to treat erectile dysfunction, osteoporosis and dementia in traditional Chinese medicine. Recently, ICS II attracts great interest due to its broad-spectrum anti-cancer property. ICS II shows an anti-inflammatory potential both in cancer treatment and cerebral ischemia-reperfusion. It is not yet clear whether the anti-inflammatory effect of ICS II could delay progression of AD. Therefore, the current study aimed to investigate the effects of ICS II on the behavioral deficits, Aβ levels, neuroinflammatory responses and apoptosis in Aβ25-35-treated rats. We found that bilateral hippocampal injection of Aβ25-35 induced cognitive impairment, neuronal damage, along with increase of Aβ, inflammation and apoptosis in hippocampus of rats. However, treatment with ICS II 20 mg/kg could improve the cognitive deficits, ameliorate neuronal death, and reduce the levels of Aβ in the hippocampus. Furthermore, ICS II could suppress microglial and astrocytic activation, inhibit expression of IL-1β, TNF-α, COX-2, and iNOS mRNA and protein, and attenuate the Aβ induced Bax/Bcl-2 ratio elevation and caspase-3 activation. In conclusion, these results showed that ICS II could reverse Aβ-induced cognitive deficits, possibly via the inhibition of neuroinflammation and apoptosis, which suggested a potential protective effect of ICS II on AD.

The Anticancer Properties of Herba Epimedii and Its Main Bioactive Componentsicariin and Icariside II

Cancer is one of the leading causes of deaths worldwide. Compounds derived from traditional Chinese medicines have been an important source of anticancer drugs and adjuvant agents to potentiate the efficacy of chemotherapeutic drugs and improve the side effects of chemotherapy. HerbaEpimedii is one of most popular herbs used in China traditionally for the treatment of multiple diseases, including osteoporosis, sexual dysfunction, hypertension and common inflammatory diseases. Studies show HerbaEpimedii also possesses anticancer activity. Flavonol glycosides icariin and icariside II are the main bioactive components of HerbaEpimedii. They have been found to possess anticancer activities against various human cancer cell lines in vitro and mouse tumor models in vivo via their effects on multiple biological pathways, including cell cycle regulation, apoptosis, angiogenesis, and metastasis, and a variety of signaling pathways including JAK2-STAT3, MAPK-ERK, and PI3k-Akt-mTOR. The review is aimed to provide an overview of the current research results supporting their therapeutic effects and to highlight the molecular targets and action mechanisms.

Anti-Cancer Properties of the Naturally Occurring Aphrodisiacs: Icariin and Its Derivatives

Epimedium (family Berberidaceae), commonly known as Horny Goat Weed or Yin Yang Huo, is commonly used as a tonic, aphrodisiac, anti-rheumatic and anti-cancer agent in traditional herbal formulations in Asian countries such as China, Japan, and Korea. The major bioactive compounds present within this plant include icariin, icaritin and icariside II. Although it is best known for its aphrodisiac properties, scientific and pharmacological studies suggest it possesses broad therapeutic capabilities, especially for enhancing reproductive function and osteoprotective, neuroprotective, cardioprotective, anti-inflammatory and immunoprotective effects. In recent years, there has been great interest in scientific investigation of the purported anti-cancer properties of icariin and its derivatives. Data from in vitro and in vivo studies suggests these compounds demonstrate anti-cancer activity against a wide range of cancer cells which occurs through various mechanisms such as apoptosis, cell cycle modulation, anti-angiogenesis, anti-metastasis and immunomodulation. Of note, they are efficient at targeting cancer stem cells and drug-resistant cancer cells. These are highly desirable properties to be emulated in the development of novel anti-cancer drugs in combatting the emergence of drug resistance and overcoming the limited efficacy of current standard treatment. This review aims to summarize the anti-cancer mechanisms of icariin and its derivatives with reference to the published literature. The currently utilized applications of icariin and its derivatives in cancer treatment are explored with reference to existing patents. Based on the data compiled, icariin and its derivatives are shown to be compounds with tremendous potential for the development of new anti-cancer drugs.

2'-Hydroxy-4-methylsulfonylchalcone enhances TRAIL-induced apoptosis in prostate cancer cells

Prostate cancer is the most common malignant cancer in men and the second leading cause of cancer deaths. Previously, we have shown that 2'-hydroxy-4-methylsulfonylchalcone (RG003) induced apoptosis in prostate cancer cell lines PC-3 and DU145. Although tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising anticancer agent, some cancer cells are resistant to TRAIL treatment. PC-3 and LNCaP prostatic cancer cell lines have been reported to be resistant to TRAIL-induced apoptosis. Here, we show for the first time that RG003 overcomes TRAIL resistance in prostate cancer cells. RG003 can enhance TRAIL-induced apoptosis through DR5 upregulation and downregulation of Bcl-2, PI3K/Akt, NF-κB, and cyclooxygenase-2 (COX-2) survival pathways. When used in combined treatment, RG003 and TRAIL amplified TRAIL-induced activation of apoptosis effectors and particularly activation of caspase-8 and the executioner caspase-3, leading to increased poly-ADP-ribose polymerase cleavage and DNA fragmentation in prostate cancer cells. Furthermore, we showed that RG003 reduced COX-2 expression in cells. Previously, we showed that COX-2 was involved in resistance to an apoptosis mechanism; then, its inhibition by RG003 could render cells more sensitive to TRAIL treatment. We showed that nuclear factor-κB activation was inhibited after RG003 treatment. This inhibition was correlated with reduction in COX-2 expression and induction of apoptosis. Overall, we conclude, for the first time, that RG003 can enhance TRAIL-induced apoptosis in human prostate cancer cells. The significance of our in-vitro study with RG003 and TRAIL combined is very encouraging, suggesting the relevance of testing this combined treatment in xenograft animal models.

CREB-binding protein regulates lung cancer growth by targeting MAPK and CPSF4 signaling pathway

CBP (CREB-binding protein) is a transcriptional co-activator which possesses HAT (histone acetyltransferases) activity and participates in many biological processes, including embryonic development, growth control and homeostasis. However, its roles and the underlying mechanisms in the regulation of carcinogenesis and tumor development remain largely unknown. Here we investigated the molecular mechanisms and potential targets of CBP involved in tumor growth and survival in lung cancer cells. Elevated expression of CBP was detected in lung cancer cells and tumor tissues compared to the normal lung cells and tissues. Knockdown of CBP by siRNA or inhibition of its HAT activity using specific chemical inhibitor effectively suppressed cell proliferation, migration and colony formation and induced apoptosis in lung cancer cells by inhibiting MAPK and activating cytochrome C/caspase-dependent signaling pathways. Co-immunoprecipitation and immunofluorescence analyses revealed the co-localization and interaction between CBP and CPSF4 (cleavage and polyadenylation specific factor 4) proteins in lung cancer cells. Knockdown of CPSF4 inhibited hTERT transcription and cell growth induced by CBP, and vice versa, demonstrating the synergetic effect of CBP and CPSF4 in the regulation of lung cancer cell growth and survival. Moreover, we found that high expression of both CBP and CPSF4 predicted a poor prognosis in the patients with lung adenocarcinomas. Collectively, our results indicate that CBP regulates lung cancer growth by targeting MAPK and CPSF4 signaling pathways.

TPGS/Phospholipids Mixed Micelles for Delivery of Icariside II to Multidrug-Resistant Breast Cancer

The biggest challenge for the treatment of multidrug resistant cancer is to deliver a high concentration of anticancer drugs to cancer cells. Icariside II is a flavonoid from Epimedium koreanum Nakai with remarkable anticancer properties, but poor solubility and significant efflux from cancer cells limited its clinical use. In our previous study, a self-assembled mixture of micelles (TPGS-Icariside II-phospholipid complex) was successfully constructed, which could substantially increase the solubility of Icariside II and inhibit the efflux on Caco-2 cells. In this study, we evaluate the anticancer effect of the mixed micelles encapsulating Icariside II (Icar-MC) on MCF-7/ADR, a multidrug-resistant breast cancer cell line. The cellular uptake of the micelles was confirmed by fluorescent coumarin-6-loaded micelles. The IC50 of Icar-MC in MCF-7/ADR was 2-fold less than the free drug. The in vitro study showed Icar-MC induced more apoptosis and lactate dehydrogenase release. Intravenous injection of Icar-MC into nude mice bearing MCF-7/ADR xenograft resulted in a better antitumor efficacy compared with the administration of free drug, without causing significant body weight changes in mice. The antitumor effect was further verified by magnetic resonance imaging and immunohistochemical assays for Ki-67, a proliferative indicator. Moreover, Icar-MC treatment also elevated Bax/Bcl-2 ratio and the expressions of cleaved caspase-3, -8, -9 and AIFM1 in tumors. This study suggests that phospholipid/TPGS mixed micelles might be a suitable drug delivery system for Icariside II to treat multidrug resistant breast cancer.

Targeting Apoptosis and Multiple Signaling Pathways with Icariside II in Cancer Cells

Cancer is the second leading cause of deaths worldwide. Despite concerted efforts to improve the current therapies, the prognosis of cancer remains dismal. Highly selective or specific blocking of only one of the signaling pathways has been associated with limited or sporadic responses. Using targeted agents to inhibit multiple signaling pathways has emerged as a new paradigm for anticancer treatment. Icariside II, a flavonol glycoside, is one of the major components of Traditional Chinese Medicine Herba epimedii and possesses multiple biological and pharmacological properties including anti-inflammatory, anti-osteoporosis, anti-oxidant, anti-aging, and anticancer activities. Recently, the anticancer activity of Icariside II has been extensively investigated. Here, in this review, our aim is to give our perspective on the current status of Icariside II, and discuss its natural sources, anticancer activity, molecular targets and the mechanisms of action with specific emphasis on apoptosis pathways which may help the further design and conduct of preclinical and clinical trials. Icariside II has been found to induce apoptosis in various human cancer cell lines of different origin by targeting multiple signaling pathways including STAT3, PI3K/AKT, MAPK/ERK, COX-2/PGE2 and β-Catenin which are frequently deregulated in cancers, suggesting that this collective activity rather than just a single effect may play an important role in developing Icariside II into a potential lead compound for anticancer therapy. This review suggests that Icariside II provides a novel opportunity for treatment of cancers, but additional investigations and clinical trials are still required to fully understand the mechanism of therapeutic effects to further validate it in anti-tumor therapy.

Icariside II-induced mitochondrion and lysosome mediated apoptosis is counterbalanced by an autophagic salvage response in hepatoblastoma

In this study, the anti-cancer effect of Icariside II (IS), a natural plant flavonoid, against hepatoblastoma cells and the underlying mechanisms were investigated. The in vitro and in vivo studies show that IS decreased the viability of human hepatoblastoma HepG2 cells in a concentration- and time-dependent manner and inhibited tumor growth in mice transplanted with H22 liver carcinomas. IS impaired mitochondria and lysosomes as evidenced by signs of induced mitochondrial and lysosomal membrane permeabilization, resulting in caspase activation and apoptosis. SQSTM1 up-regulation and autophagic flux measurements demonstrated that IS exposure also impaired autophagosome degradation which resulted in autophagosome accumulation, which plays a pro-survival role as the genetic knockdown of LC3B further sensitized the IS-treated cells. Electron microscopy images showed that autophagosome engulfs IS-impaired mitochondria and lysosomes, thus blocking cytotoxicity induced by further leakage of the hydrolases from lysosomes and pro-apoptosis members from mitochondria. In conclusion, these data suggest that IS plays multiple roles as a promising chemotherapeutic agent that induces cell apoptosis involving both mitochondrial and lysosomal damage.

Berberis libanotica extract targets NF-κB/COX-2, PI3K/Akt and mitochondrial/caspase signalling to induce human erythroleukemia cell apoptosis

The aim of this study was to describe and understand the relationship between cyclooxygenase-2 (COX-2) expression and apoptosis rate in erythroleukemia cells after apoptosis induction by Berberis libanotica (Bl) extract. To achieve this goal we used erythroleukemia cell lines expressing COX‑2 (HEL cell line) or not (K562 cell line). Moreover, we made use of COX‑2 cDNA to overexpress COX‑2 in K562 cells. In light of the reported chemopreventive and chemosensitive effects of natural products on various tumor cells and animal models, we postulated that our Bl extract may mediate their effects through apoptosis induction with suppression of cell survival pathways. Our study is the first report on the specific examination of intrinsic apoptosis and Akt/NF-κB/COX‑2 pathways in human erythroleukemia cells upon Bl extract exposure. Even if Bl extract induced apoptosis of three human erythroleukemia cell lines, a dominant effect of Bl extract treatment on K562 cells was observed resulting in activation of the late markers of apoptosis with caspase-3 activation, PARP cleavage and DNA fragmentation. Whereas, we showed that Bl extract reduced significantly expression of COX‑2 by a dose-dependent manner in HEL and K562 (COX‑2+) cells. Furthermore, in regard to our results, it is clear that the simultaneous inhibition of Akt and NF-κB signalling can significantly contribute to the anticancer effects of Bl extract in human erythroleukemia cells. We observed that the Bl extract is clearly more active than the berberine alone on the induction of DNA fragmentation in human erythro-leukemia cells.

Upregulation of death receptor 5 and activation of caspase 8/3 play a critical role in ergosterol peroxide induced apoptosis in DU 145 prostate cancer cells

Background

Though ergosterol peroxide (EP) derived from Neungyi mushrooms (Sarcodon aspratus) was known to have cytotoxic, apoptotic, anti-inflammatory and antimycobacterial effects, the underlying molecular mechanism of EP still remains unclear. Thus, in the present study, the apoptotic mechanism of EP was elucidated in DU 145 prostate cancer cells.

Methods

Cell viability of prostate cancer cells was measured by MTT assay. To see whether EP induces the apoptosis, FACS, western blot and TUNEL assay were performed. To determine the role of Death receptor (DR) 5 molecules in EP-induced apoptosis in DU 145 prostate cancer cells, the silencing of DR 5 was performed by using siRNAs.

Results

EP showed significant cytotoxicity against DU 145, PC 3, M2182 prostate cancer cells. Also, EP effectively increased the sub G1 population and terminal deoxynucleotidyl transferase DUTP nick end labeling (TUNEL) positive cells in DU 145 prostate cancer cells. Furthermore, western blotting revealed that EP cleaved poly (ADP-ribose) polymerase (PARP) and caspase 8/3, attenuated the expression of fluorescence loss in photobleaching (FLIP), Bcl-_XL and Bcl-2 as well as activated Bax, Fas-associated death domain (FADD) and DR 5 in a concentration dependent manner in DU 145 prostate cancer cells. Conversely, caspase 8 inhibitor Z-IETD-FMK blocked the apoptotic ability of EP to cleave PARP and an increase of sub G1 population in DU 145 prostate cancer cells. Likewise, the silencing of DR 5 suppressed the cleavages of PARP induced by EP in DU 145 prostate cancer cells.

Conclusion

Overall, our findings suggest that ergosterol peroxide induces apoptosis via activation of death receptor 5 and caspase 8/3 in DU 145 prostate cancer cells as a cancer chemopreventive agent or dietary factor.

Icariside II inhibits cell proliferation and induces cell cycle arrest through the ROS-p38-p53 signaling pathway in A375 human melanoma cells

Icariside II (IS) is a metabolite of icariin, which is derived from Herba Epimedii. In the present study, the antiproliferative effects of IS on A375 human melanoma cells were examined in vitro and a possible mechanism through the ROS-p38-p53 pathway is discussed. A cell WST-8 assay revealed that treatment with IS markedly reduced cell viability from 77 to 21% (25 and 100 µM, respectively), and cell counting demonstrated that IS treatment reduced cell proliferation. IS treatment also induced cell cycle arrest of A375 cells at the G0/G1 and G2/M transitions and inhibited the expression of cell-cycle related proteins, including cyclin E, cyclin-dependent kinase 2 (CDK2), cyclin B1 and phosphorylated cyclin-dependent kinase 1 (P-CDK1). In this study, it was determined that IS inhibits cell proliferation and induces cell cycle arrest through the generation of reactive oxygen species and activation of p38 and p53. These findings were further supported by the evidence that pretreatment with N-acetyl-L-cysteine, SB203580 or pifithrin-α significantly blocked IS-induced reduction of cell viability, increase of cell death and cell cycle arrest. In conclusion, IS inhibits cell proliferation and induces cell cycle arrest. Crucially, it was confirmed that these effects were mediated at least in part by activating the ROS-p38-p53 pathway.

Icariside II induces apoptosis of melanoma cells through the downregulation of survival pathways

This study evaluated the antitumor effects of icariside II (IS), isolated from Herba Epimedii, on in vitro and in vivo models of melanoma and determined its mechanism of apoptosis. Mouse (B16) and human (A375, SK-MEL-5) melanoma cell lines were treated with IS at different concentrations (0-100 μM). Cell viability and proliferation was detected by WST-1 assay and with the xCELLigence system, respectively. Apoptosis was measured by the annexin-V/PI flow cytometric assay. Western blot was used to measure cleaved caspase 3, survivin, P-STAT3, P-ERK and P-AKT. B16 and A375 cells were injected subcutaneously into C57BL/6J and BALB/c-nu mice, respectively. After 1 wk, IS solution at (50 mg/kg, 100 mg/kg) was administered by intraperitoneal injection 3 times for a week. Tumor size was measured with an electronic digital caliper. IS inhibited the proliferation of melanoma cells in a dose- and time-dependent manner. Treatment of A375 cells with IS resulted in an increased number of apoptotic cells ranging from 5.6% to 26.3% mirrored by increases in cleaved caspase-3 and a decrease in survivin expression. IS significantly inhibited the activation of the JAK-STAT3 and MAPK pathways but promoted an unsustained activation peak of the PI3K-AKT pathway. IS administration (50 mg/kg) resulted in a 47.5% decreased tumor volume in A375 bearing mice. Furthermore, IS administration (50 mg/kg, 100 mg/kg) resulted in 41% and 49% decreased tumor volume in B16 bearing mice, respectively. IS dramatically inhibited the proliferation of melanoma cells in vivo and in vitro through the regulation of apoptosis. These effects demonstrate the ability of IS to effectively overcome the survival signals of tumor cells, which support further preclinical evaluation of IS in cancer as a new potential chemotherapeutic agent.

Novel methylsulfonyl chalcones as potential antiproliferative drugs for human prostate cancer: involvement of the intrinsic pathway of apoptosis

Limited success has been achieved in extending the survival of patients with metastatic and hormone-refractory prostate cancer (HRPC). There is a strong need for novel agents in the treatment and prevention of HRPC. In the present study, the apoptotic mechanism of action of RG003 (2'-hydroxy-4-methylsulfonylchalcone) and RG005 (4'-chloro-2'-hydroxy-4-methylsulfonylchalcone) in association with intracellular signalling pathways was investigated in the hormone-independent prostate carcinoma cells PC-3 and DU145. We showed that these compounds induced apoptosis through the intrinsic pathway but not through the extrinsic one. We showed that synthetic chalcones induced an activation of caspase-9 but not caspase-8 in PC-3 cells. Even if both chalcones induced apoptosis in PC-3 cells, a dominant effect of RG003 treatment was observed resulting in a disruption of ∆ψm, caspase-9 and caspase-3 activation, PARP cleavage and DNA fragmentation. Furthermore, in regard to our results, it is clear that the simultaneous inhibition of Akt and NF-κB signalling can significantly contribute to the anticancer effects of RG003 and RG005 in PC-3 prostate cancer cells. NF-κB inhibition was correlated with the reduction of COX-2 expression and induction of apoptosis. Our results clearly indicate for the first time that RG003 and RG005 exert their potent anti‑proliferative and pro-apoptotic effects through the modulation of Akt/NF-κB/COX-2 signal transduction pathways in PC-3 prostate cancer cells with a dominant effect for RG003.

Icariside II induces apoptosis via inhibition of the EGFR pathways in A431 human epidermoid carcinoma cells

Improvements in skin cancer treatment are likely to derive from novel agents targeting the molecular pathways that promote tumor cell growth and survival. Icariside II (IS) is a metabolite of icariin, which is derived from Herba Epimedii. The aim of the present study was to evaluate the antitumor effects of IS and to determine the mechanism of apoptosis in A431 human epidermoid carcinoma cells. A431 cells were treated with IS (0‑100 µM) for 24 or 48 h and cell viability was detected using the WST‑8 assay. Apoptosis was measured by the Annexin‑V/propidium iodide (PI) flow cytometric assay. Western blot analysis was used to measure the expression of cleaved caspase‑9, cleaved poly ADP ribose polymerase (PARP), phosphorylated signal transducer and activator of transcription 3 (P‑STAT3), phosphorylated extracellular signal-regulated kinase (P‑ERK), and P‑AKT. A431 cells were also pretreated with IS (0‑100 µM) 2 h prior to treatment with epidermal growth factor (EGF; 100 ng/ml) for 10 min. Phosphorylated EGF receptor (P‑EGFR), P‑STAT3, P‑ERK and P‑AKT were detected by western blot analysis. The results demonstrated that IS inhibited the cell viability of the A431 cells in a dose‑dependent manner. Pretreatment with LY294002 [a phosphatidylinositol 3-kinase (PI3K) inhibitor], EGF (an EGFR agonist) and AG1478 (an EGFR inhibitor) partially reversed IS‑induced decreases in cell viability. Treatment with 50 µm IS resulted in an increased number of apoptotic cells mirrored by increases in cleaved caspase‑9 and cleaved PARP. In addition, treatment with 50 µM IS significantly inhibited the activation of the Janus kinase (JAK)‑STAT3 and mitogen‑activated protein kinase (MAPK)‑ERK pathways, but promoted the activation of the PI3K‑AKT pathway. Furthermore, IS effectively inhibited the EGF-induced activation of the EGFR pathways. In conclusion, IS inhibited the cell viability of the A431 cells through the regulation of apoptosis. These effects were mediated, at least in part, by inhibiting the activation of the EGFR pathways.