A novel anticancer agent, icaritin, induced cell growth inhibition, G1 arrest and mitochondrial transmembrane potential drop in human prostate carcinoma PC-3 cells

Transplant oncology and anti-cancer immunosuppressants

Organ transplantation is a life-saving intervention that enhances the quality of life for patients with end-stage organ failure. However, long-term immunosuppressive therapy is required to prevent allogeneic graft rejection, which inadvertently elevates the risk of post-transplant malignancies, especially for liver transplant recipients with a prior history of liver cancer. In response, the emerging field of transplant oncology integrates principles from oncology and immunology to improve outcomes for patients at high risk of tumor occurrence or recurrence following transplantation. Therefore, it is of substantial clinical significance to develop immunosuppressants that possess both immunosuppressive and anti-tumor properties. For instance, mTOR inhibitors demonstrate anti-tumor effects among antimetabolite immunosuppressive drugs, and recent studies indicate that capecitabine, an antimetabolite chemotherapeutic, may also exhibit immunosuppressive activity in the clinic for liver transplants suffering from hepatocellular carcinoma. This review systematically explores potential immunosuppressants with dual anti-tumor and immunosuppressive effects to support the management of transplant patients at elevated risk of tumor occurrence or recurrence.

Pharmacological actions of the bioactive compounds of Epimedium on the male reproductive system: current status and future perspective

ABSTRACT

Compounds isolated from Epimedium include the total flavonoids of Epimedium , icariin, and its metabolites (icaritin, icariside I, and icariside II), which have similar molecular structures. Modern pharmacological research and clinical practice have proved that Epimedium and its active components have a wide range of pharmacological effects, especially in improving sexual function, hormone regulation, anti-osteoporosis, immune function regulation, anti-oxidation, and anti-tumor activity. To date, we still need a comprehensive source of knowledge about the pharmacological effects of Epimedium and its bioactive compounds on the male reproductive system. However, their actions in other tissues have been reviewed in recent years. This review critically focuses on the Epimedium , its bioactive compounds, and the biochemical and molecular mechanisms that modulate vital pathways associated with the male reproductive system. Such intrinsic knowledge will significantly further studies on the Epimedium and its bioactive compounds that protect the male reproductive system and provide some guidances for clinical treatment of related male reproductive disorders.

Potential of natural products and gut microbiome in tumor immunotherapy

Immunotherapy is a novel treatment approach for malignant tumors, which has opened a new journey of anti-tumor therapy. Although some patients will show a positive response to immunotherapy, unfortunately, most patients and cancer types do not achieve an ideal response to immunotherapy. Therefore, it is urgent to search for the pathogenesis of sensitized immunotherapy. This review indicates that Fusobacterium nucleatum, Coprobacillus cateniformis, Akkermansia muciniphila, Bifidobacterium, among others, as well as intestinal microbial metabolites are closely associated with resistance to anti-tumor immunotherapy. While natural products of pectin, inulin, jujube, anthocyanins, ginseng polysaccharides, diosgenin, camu-camu, and Inonotus hispidus (Bull).Fr. P. Karst, Icariside I, Safflower yellow, Ganoderma lucidum, and Ginsenoside Rk3, and other Chinese native medicinal compound prescriptions to boost their efficacy of anti-tumor immunotherapy through the regulation of microbiota and microbiota metabolites. However, current research mainly focuses on intestinal, liver, and lung cancer. In the future, natural products could be a viable option for treating malignant tumors, such as pancreatic, esophageal, and gastric malignancies, via sensitizing immunotherapy. Besides, the application characteristics of different types, sources and efficacy of natural products in different immune resistance scenarios also need to be further clarified through the development of future immunotherapy-related studies.

Glyco-conjugation in 3-β-anhydroicaritine

A convenient method has been developed for the glycol-conjugation in 3-position of β-anhydroicaritine in a reasonable yield. The structure of the 3-glycosylated β-anhydroicaritine derivatives was confirmed to be correct by 1H NMR, 13C NMR and HRMS spectrum. These compounds are less soluble than icaritin, but more soluble than icariside II in CCl4. The screening results showed that compounds 12h, 12i and 12j had higher cytotoxicity to HepG2 and MCF-7 at a concentration of 50 μM.

Icariside I enhances the effects of immunotherapy in gastrointestinal cancer via targeting TRPV4 and upregulating the cGAS-STING-IFN-I pathway

Gastrointestinal cancer is among the most common cancers worldwide. Immune checkpoint inhibitor-based cancer immunotherapy has become an innovative approach in cancer treatment; however, its efficacy in gastrointestinal cancer is limited by the absence of infiltration of immune cells within the tumor microenvironment. Therefore, it is therefore urgent to develop a novel therapeutic drug to enhance immunotherapy. In this study, we describe a previously unreported potentiating effect of Icariside I (ICA I, GH01), the main bioactive compound isolated from the Epimedium species, on anti-tumor immune responses. Mechanistically, molecular docking and SPR assay result show that ICA I binding with TRPV4. ICA I induced intracellular Ca2+ increasing and mitochondrial DNA release by targeting TRPV4, which triggered cytosolic ox-mitoDNA release. Importantly, these intracellular ox-mitoDNA fragments were taken up by immune cells in the tumor microenvironment, which amplified the immune response. Moreover, our study shows the remarkable efficacy of sequential administration of ICA I and anti-α-PD-1 mAb in advanced tumors and provides a strong scientific rationale for recommending such a combination therapy for clinical trials. ICA I enhanced the anti-tumor effects with PD-1 inhibitors by regulating the TRPV4/Ca2+/Ox-mitoDNA/cGAS/STING axis. We expect that these findings will be translated into clinical therapies, which will benefit more patients with cancer in the near future.

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.

Progress in phosphorylation of natural products

Natural medicines are a valuable resource for the development of new drugs. However, factors such as low solubility and poor bioavailability of certain constituents have hindered their efficacy and potential as pharmaceuticals. Structural modification of natural products has emerged as an important research area for drug development. Phosphorylation groups, as crucial endogenous active groups, have been extensively utilized for structural modification and development of new drugs based on natural molecules. Incorporating phosphate groups into natural molecules not only enhances their stability, bioavailability, and pharmacological properties, but also improves their biological activity by altering their charge, hydrogen bonding, and spatial structure. This review summarizes the phosphorylation mechanism, modification approaches, and biological activity enhancement of natural medicines. Notably, compounds such as polysaccharides, flavonoids, terpenoids, anthraquinones, and coumarins exhibit increased antioxidation, anticancer, antiviral, immune regulatory, Antiaging, enzyme inhibition, bacteriostasis, liver protection, and lipid-lowering effects following phosphorylation modification.

Icaritin-curcumol activates CD8+ T cells through regulation of gut microbiota and the DNMT1/IGFBP2 axis to suppress the development of prostate cancer

BACKGROUND

Prostate cancer (PCa) incidence and mortality rates are rising. Our previous research has shown that the combination of icariin (ICA) and curcumol (CUR) induced autophagy and ferroptosis in PCa cells, and altered lipid metabolism. We aimed to further explore the effects of the combination of ICA and CUR on gut microbiota, metabolism, and immunity in PCa.

METHODS

A mouse subcutaneous RM-1 cell tumor model was established. 16 S rRNA sequencing was performed to detect changes in fecal gut microbiota. SCFAs in mouse feces, and the effect of ICA-CUR on T-cell immunity, IGFBP2, and DNMT1 were examined. Fecal microbiota transplantation (FMT) was conducted to explore the mechanism of ICA-CUR. Si-IGFBP2 and si/oe-DNMT1 were transfected into RM-1 and DU145 cells, and the cells were treated with ICA-CUR to investigate the mechanism of ICA-CUR on PCa development.

RESULTS

After treatment with ICA-CUR, there was a decrease in tumor volume and weight, accompanied by changes in gut microbiota. ICA-CUR affected SCFAs and DNMT1/IGFBP2/EGFR/STAT3/PD-L1 pathway. ICA-CUR increased the positive rates of CD3+CD8+IFN-γ, CD3+CD8+Ki67 cells, and the levels of IFN-γ and IFN-α in the serum. After FMT (with donors from the ICA-CUR group), tumor volume and weight were decreased. SCFAs promote tumor development and the expression of IGFBP2. In vitro, DNMT1/IGFBP2 promotes cell migration and proliferation. ICA-CUR inhibits the expression of DNMT1/IGFBP2.

CONCLUSIONS

ICA-CUR mediates the interaction between gut microbiota and the DNMT1/IGFBP2 axis to inhibit the progression of PCa by regulating immune response and metabolism, suggesting a potential therapeutic strategy for PCa.

New insights into the anticancer therapeutic potential of icaritin and its synthetic derivatives

Icaritin is a natural prenylated flavonoid derived from the Chinese herb Epimedium. The compound has shown antitumor effects in various cancers, especially hepatocellular carcinoma (HCC). Icaritin exerts its anticancer activity by modulating multiple signaling pathways, such as IL-6/JAK/STAT3, ER-α36, and NF-κB, affecting the tumor microenvironment and immune system. Several clinical trials have evaluated the safety and efficacy of icaritin in advanced HCC patients with poor prognoses, who are unsuitable for conventional therapies. The results have demonstrated that icaritin can improve survival, delay progression, and produce clinical benefits in these patients, with a favorable safety profile and minimal adverse events. Moreover, icaritin can enhance the antitumor immune response by regulating the function and phenotype of various immune cells, such as CD8+ T cells, MDSCs, neutrophils, and macrophages. These findings suggest that icaritin is a promising candidate for immunotherapy in HCC and other cancers. However, further studies are needed to elucidate the molecular mechanisms and optimal dosing regimens of icaritin and its potential synergistic effects with other agents. Therefore, this comprehensive review of the scientific literature aims to summarize advances in the knowledge of icaritin in preclinical and clinical studies as well as the pharmacokinetic, metabolism, toxicity, and mechanisms action to recognize the main challenge, gaps, and opportunities to develop a medication that cancer patients can use. Thus, our main objective was to clarify the current state of icaritin for use as an anticancer drug.

Mechanism of salidroside in the treatment of endometrial cancer based on network pharmacology and molecular docking

Salidroside is a natural product of phenols, which has a wide scape of pharmacological effects, but its pharmacological effects and molecular mechanism on endometrial cancer are not clear. To systematically explore the pharmacological effects and molecular mechanisms of salidroside on endometrial cancer through the method of network pharmacology. The possible target genes of salidroside were obtained through different pharmacological databases and analysis platforms, and then the relevant target genes of endometrial cancer were obtained through the GeneCards website, and the target genes were uniformly converted into standardized gene names with Uniprot. The collected data were then processed to obtain common target genes and further analyzed through the String website to construct a protein-protein interaction (PPI) network, followed by gene ontology (GO) functional annotation and Kyoto Gene and Genome Encyclopedia (KEGG) pathway analysis. We further interpreted the molecular mechanism of salidroside for the treatment of endometrial cancer by constructing a "drug component-target gene-disease" network. Finally, we performed molecular docking to validate the binding conformation between salidroside and the candidate target genes. There were 175 target genes of salidroside after normalization, among which 113 target genes interacted with endometrial cancer. GO analysis indicated that the anti-endometrial cancer effect of salidroside may be strongly related to biological processes such as apoptosis and response to drug. KEGG analysis indicated that its mechanism may be related to pathway in cancer and PI3K-AKT signaling pathway. Molecular docking showed that salidroside had high affinity with five key genes. Based on the novel network pharmacology and molecular docking validation research methods, we have revealed for the first time the potential mechanism of salidroside in the therapy of endometrial cancer.

Icaritin: A phytomolecule with enormous pharmacological values

Pharmacological studies on flavonoids have always drawn much interest for many years. Icaritin (ICT), a representative flavone containing an 8-prenyl group, is a principal compound detected in medicinal plants of the genus Epimedum, the family Berberidaceae. Experimental results in the phytochemistry and pharmacology of this molecule are abundant now, but a deep overview has not been carried out. The goal of this review is to provide an insight into the natural observation, biosynthesis, biotransformation, synthesis, pharmacology, and pharmacokinetics of prenyl flavone ICT. The relevant data on ICT was collected from bibliographic sources, like Google Scholar, Web of Science, Sci-Finder, and various published journals. "Icaritin" alone or in combination is the main keyword to seek for references, and references have been updated till now. ICT is among the characteristic phytomolecules of Epimedum plants. Bacteria monitored its biosynthesis and biotransformation, while this agent was rapidly synthesized from phloroglucinol by microwave-assistance Claisen rearrangement. ICT is a potential agent in numerous in vitro and in vivo pharmacological records, which demonstrated its role in cancer treatments via apoptotic-related mechanisms. It also brings in various health benefits since it reduced harmful effects on the liver, lung, heart, bone, blood, and skin, and improved immune responses. Pharmacokinetic outcomes indicated that its metabolic pathway involved hydration, hydroxylation, dehydrogenation, glycosylation, and glucuronidation. Molecule mechanisms of action at a cellular level are predominant, but clinical studies are expected to get more. Structure-activity relationship records seem insufficient, and the studies on nano-combined approaches to improve its soluble property in living bodied medium are needed.

Case report: A case study on the treatment using icaritin soft capsules in combination with lenvatinib achieving impressive PR and stage reduction in unresectable locally progressive pancreatic cancer and a literature review

Background: Pancreatic cancer is one of the most deadly malignancies in the world. It is characterized by rapid progression and a very poor prognosis. The five-year survival rate of pancreatic cancer in China is only 7.2%, which is the lowest among all cancers and the use of combined paclitaxel albumin, capecitabine, and digital has been the clinical standard treatment for advanced pancreatic cancer since 1997. Also, the application of multidrug combinations is often limited by the toxicity of chemotherapy. Therefore, there is an urgent need for a more appropriate and less toxic treatment modality for pancreatic cancer. Case presentation: The patient was a 79-year-old woman, admitted to the hospital with a diagnosis of unresectable locally advanced pancreatic cancer (T3N0M0, stage IIA), with its imaging showing overgrowth of SMV involvement and unresectable reconstruction of the posterior vein after evaluation. As the patient refused chemotherapy, lenvatinib (8 mg/time, qd) and icaritin soft capsules (three tablets/time, bid) were recommended according to our past experience and a few clinical research cases. The tumor lesion was greatly reduced by 57.5% after the treatment, and the extent of vascular involvement also decreased. The aforementioned medication resulted in a significant downstaging of the patient's tumor. Conclusion: Better results were achieved in the treatment with icaritin soft capsules and lenvatinib in this case. Because of its less toxic effect on the liver and kidney and bone marrow suppression, it was suitable to combine icaritin soft capsules with targeted drugs for treating intermediate and advanced malignancies, which brings hope to patients who cannot or refuse to take chemotherapy.

The location of estrogen receptor variant ER-α36 is associated with the invasion of glioblastoma

Glioblastoma (GBM) is the most common central nervous system tumor and is associated with poor outcomes. There have been no significant improvements in GBM mortality in recent decades. ER-α36 is a variant of ER-α66 that may be involved in carcinoma growth and proliferation via genomic and nongenomic mechanisms. This variant might play an essential role in tamoxifen resistance of several tumors. Previously, our laboratory found that ER-α36 is expressed in GBM and participates in proliferation; nevertheless, the role of ER-α36 in GBM invasion remains unknown. This study aimed to determine the effects of the ER-α36 modulator SNG162 on GBM growth and invasion. U251 cells, U87cells, and U87-36KD cells with knockdown of ER-α36 expression were cultured under the two-dimensional and the three-dimensional (3D) environments. GBM cells growth was examined by cell counting, flow cytometry, western blot, and MTT assays. Invasiveness was measured using confocal microscopy in the 3D environment. Growth of U87 cells with downregulated EGFR and ER-α36 expression was significantly reduced after treatment with 1 µM, 3 µM, and 5 µM of SNG162; growth inhibition in U251 cells was more potent than in U87 cells, although the expression level of ER-α36 in U251 cells was lower than in U87 cells. We found that 1 μM SNG162 suppressed E₂-induced MAPK/ERK pathway activation in U87 cells. We also showed that SNG162 inhibited U87 cells invasion; however, it did not significantly affect U251 and U87-36KD cells invasion using the 3D culture method. Finally, we determined that ER-α36 was expressed in the nucleus of invading GBM cells, and SNG162 significantly inhibited the expression of ER-α36 in these cells. SNG162 inhibited the expression of EGFR on cell membranes of non-invasive GBM cells. These results suggest that SNG162 could be a therapeutic agent for GBM by targeting ER-α36.

UHPLC-ESI-QE-Orbitrap-MS based metabolomics reveals the antioxidant mechanism of icaritin on mice with cerebral ischemic reperfusion

Background

Icaritin (ICT) has been previously demonstrated to display protective effects against cerebral ischemic reperfusion (I/R) by inhibiting oxidative stress, but the mechanism remains unclear. This study aimed to explore the mechanism from the perspective of metabolomics.

Methods

A mice cerebral artery occlusion/reperfusion (MCAO/R) model was explored to mimic cerebral ischemic reperfusion and protective effect of ICT was assessed by neurologic deficit scoring, infarct volume and brain water content. Ultra-high-performance liquid chromatography electrospray ionization orbitrap tandem mass spectrometry (UHPLC-ESI-QE-Orbitrap-MS) based metabolomic was performed to explore potential biomarkers. Brain tissue metabolic profiles were analyzed and metabolic biomarkers were identified through multivariate data analysis. The protein levels of Nrf2, HO-1 and HQO1 were assayed by western blot. The release of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) were detected using corresponding assay kits.

Results

The results showed that after ICT treatment, the neurological deficit, cerebral infarction area, brain edema and the level of MDA in brain tissue of MCAO/R mice were significantly reduced. Meanwhile, ICT enhanced the activity of SOD, CAT and GSH-Px. Western blot results confirmed that ICT up-regulated the protein levels of antioxidant-related protein including Nrf2, HO-1 and NQO1. According to the metabolomic profiling of brain tissues, clear separations were observed among the Sham, Model and ICT groups. A total of 44 biomarkers were identified, and the identified biomarkers were mainly related to linoleic acid metabolism, arachidonic acid metabolism, alanine, aspartate and glutamate metabolism, arginine biosynthesis, arginine and proline metabolism, D-glutamine and D-glutamate metabolism, taurine and hypotaurine metabolism and purine metabolism, respectively. At the same time, the inhibitory effect of ICT on arachidonic acid and linoleic acid in brain tissue, as well as the promoting effect on taurine, GABA, NAAG, may be the key factors for the anti-neurooxidative function of mice after MCAO/R injury.

Conclusion

Our results demonstrate that ICT has benefits for MCAO/R injury, which are partially related to the suppression of oxidative stress via stimulating the Nrf2 signaling and regulating the production of arachidonic acid, linoleic acid, taurine, GABA, NAAG in brain tissue.

Icariin as an emerging candidate drug for anticancer treatment: Current status and perspective

Icariin (ICA) is a kind of natural flavonoid compound monomer, which is derived from the extract of dried stems and leaves of Epimedium. Modern pharmacological studies have found that ICA has broad bioactive function in affecting the biological processes of a variety of cancers, including breast cancer, colorectal cancer, hepatocellular carcinoma, esophageal cancer and other cancers, which indicates that ICA has promising application value in the treatment of cancer patients in the future. Nevertheless, the targets and molecular mechanisms of ICA in cancer treatment have not been elucidated in detail. Therefore, in this review, we systematically summarizes the current research progress of ICA in a series of cancers. In particular, an emphasis is placed on the mechanism of ICA and its future development direction, aiming at providing relevant theoretical basis for the development and application of ICA in the future cancer treatment strategies.

Retraction

Han N, Zhang B, Wei X, Yu L. The inhibitory function of icariin in cell model of benign prostatic hyperplasia by upregulation of miR-7. BioFactors. 2023;49:203. https://doi.org/10.1002/biof.1591 This article, published online on 29 November 2019 in Wiley Online Library, has been retracted by agreement between the International Union of Biochemistry and Molecular Biology, the Editor in Chief (Dr. Angelo Azzi), and Wiley Periodicals LLC. The retraction has been agreed following an investigation based on allegations raised by a third party. Evidence for image manipulation was found in figures 1, 3, 4, 5, 6, and 7. As a result, the conclusions of this article are considered to be invalid.

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.

Anticancer natural products targeting immune checkpoint protein network

Normal cells express surface proteins that bind to immune checkpoint proteins on immune cells to turn them off, whereby the immune system does not attack normal healthy cells. Cancer cells can also utilize this same protective mechanism by expressing surface proteins that can interact with checkpoint proteins on immune cells to overcome the immune surveillance. Immunotherapy is making the best use of the body's own immune system to reinforce anti-tumor responses. The most generally used immunotherapy is the control of immune checkpoints including the cytotoxic T lymphocyte-associated molecule 4 (CTLA-4), programmed cell deathreceptor 1 (PD-1), or programmed cell death ligand-1 (PD-L1). In spite of the clinical effectiveness of immune checkpoint inhibitors, the overall response rate still remains low. Therefore, there have been considerable efforts in searching for alternative immune checkpoint proteins that may work as new therapeutic targets for treatment of cancer. Recent studies have identified several additional novel immune checkpoint targets, including lymphocyte activation gene-3, T cell immunoglobulin and mucin-domain containing-3, T cell immunoglobulin and immunoreceptor tyrosine-based inhibition motif domain, V-domain Ig suppressor of T cell activation, B7 homolog 3 protein, B and T cell lymphocyte attenuator, and inducible T cell COStimulator. Natural compounds, especially those present in medicinal or dietary plants, have been investigated for their anti-tumor effects in various in vitro and in vivo models. Some phytochemicals exert anti-tumor activities based on immunoregulatioby blocking interaction between proteins involved in immune checkpoint signal transduction or regulating their expression/activity. Recently, synergistic anti-cancer effects of diverse phytochemicals with anti-PD-1/PD-L1 or anti-CTLA-4 monoclonal antibody drugs have been continuously reported. Considering an increasing attention to noteworthy therapeutic effects of immune checkpoint inhibitors in the cancer therapy, this review focuses on regulatory effects of selected phytochemicals on immune checkpoint protein network and their combinational effectiveness with immune checkpoint inhibitors targeting tumor cells.

Computer-Aided Design of α-L-Rhamnosidase to Increase the Synthesis Efficiency of Icariside I

Icariside I, the glycosylation product of icaritin, is a novel effective anti-cancer agent with immunological anti-tumor activity. However, very limited natural icariside I content hinders its direct extraction from plants. Therefore, we employed a computer-aided protein design strategy to improve the catalytic efficiency and substrate specificity of the α-L-rhamnosidase from Thermotoga petrophila DSM 13995, to provide a highly-efficient preparation method. Several beneficial mutants were obtained by expanding the active cavity. The catalytic efficiencies of all mutants were improved 16-200-fold compared with the wild-type TpeRha. The double-point mutant DH was the best mutant and showed the highest catalytic efficiency (k cat /K M : 193.52 s-1 M-1) against icariin, which was a 209.76-fold increase compared with the wild-type TpeRha. Besides, the single-point mutant H570A showed higher substrate specificity than that of the wild-type TpeRha in hydrolysis of different substrates. This study provides enzyme design strategies and principles for the hydrolysis of rhamnosyl natural products.

Icariin ameliorates metabolic syndrome-induced benign prostatic hyperplasia in rats

Metabolic syndrome (MetS) is an immense health issue that causes serious complications in aging males including BPH. Icariin (ICA) is a flavonol glycoside that exerts a plethora of pharmacological effects. The present investigation tested the potential of ICA to ameliorate benign prostatic hyperplasia (BPH) induced by MetS in rats. Animals were allocated to 5 groups in which the first and second groups were kept on water and regular food pellets. MetS was induced in the third, fourth, and fifth groups by keeping the animals on high fructose and salt diets for twelve consecutive weeks. These groups were given vehicle, ICA (25 mg/kg), and ICA (50 mg/kg), respectively. MetS was confirmed by an increase in rats' weight, accumulation of visceral fat, insulin resistance, and dyslipidemia. This was accompanied by manifestation of BPH including increased prostate weight, prostate index, and histopathological alterations. Treating the animals with both doses of ICA significantly ameliorated the increase in weight and index of the prostate as well as altered prostate histopathology. In addition, ICA significantly decreased cyclin D1 expression, upregulated Bax, and downregulated Bcl2 mRNA expression. ICA prevented lipid peroxidation, reduced glutathione depletion, and catalase exhaustion, which further lowered markers of prostate inflammation such as interleukin-6 and tumor necrosis factor-α. Moreover, ICA prevented the decrease in prostate content of phosphorylated 5'-adenosine monophosphate (AMP)-activated protein kinase (pAMPK). In conclusion, ICA protects against MetS-induced BPH. This is due to its antiproliferative, proapoptotic, antioxidant, and anti-inflammatory activities as well as the activation of AMPK.

Anticancer effects of Traditional Chinese Medicine on epithelial-mesenchymal transition（EMT） in breast cancer: Cellular and molecular targets

Breast cancer is a malignant epithelial tumor of ductal or lobular origin. Breast cancer remains the most frequently diagnosed invasive cancer in women and is the leading cause of cancer-associated mortality worldwide. Epithelial-mesenchymal transition (EMT), a phenotypic process of conversion from epithelial to mesenchymal cells, allows tumor cells to acquire infiltration and metastasization properties. Therapies directed at pathways, which are primarily involved in malignant transformation, can lead to clinical implications. In recent years, EMT has gained increasing attention as a potential therapeutic target in cancer therapy. Moreover, for the past few decades, increasing numbers of studies have suggested that Traditional Chinese Medicine(TCM) compounds can significantly inhibit the growth and development of breast cancer cells through the inhibition of EMT in breast cancer cells. This review discusses some essential signaling pathways associated with EMT and summarizes the effects and mechanism of TCM components on that inhibit EMT in breast cancer therapy.

Microbial transformation of icariin and its derivatives

Microbial transformation is an important tool to perform selective conversion of compounds to derivatives which are difficult to produce synthetically. In order to obtain icariside II and icaritin, the active components in Herba Epimedii in vivo, biotransformation studies using microbes as biocatalysts were carried out. Icariside II (2) and icaritin (3) were produced through biotransformation of icariin (1) using the fungi Hormoconis resinae and Mortierella ramanniana var. angulispora in 98% and 92% yields, respectively. In the subsequent transformation studies, 2 was deglycosylated to form 3 by Gliocladium deliquescens, whereas 3 was further converted to a novel compound icaritin-3-O-β-d-glucopyranoside (4) and previously known icaritin-3,7-O-β-d-diglucopyranoside (5) by Mucor hiemalis. Biological evaluation of these compounds using MTT assay exhibited potent cytotoxic activities against human cancer cell lines A549, A375P, and MCF-7, with icariin being the most active, indicating that glycosylation plays a role in the cytotoxic activity.

IGF-1 receptor is involved in the regulatory effects of icariin and icaritin in astrocytes under basal conditions and after an inflammatory challenge

Icariin and icaritin, the major active components of Epimedii Genus, are considered as promising drugs with anti-inflammatory, anti-aging and neuroprotective effects. Our previous studies have demonstrated that icariin and icaritin can protect against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)/1-methyl-4-phenylpyridinium (MPP⁺)-induced neurotoxicity on dopaminergic neurons via insulin-like growth factor-1 receptor (IGF-1 receptor) signaling. In the present study, we aimed to evaluate the role of IGF-1 receptor signaling in mediating the anti-inflammatory effects of icariin and icaritin against lipopolysaccharide (LPS)-induced neuroinflammation as well as their biological regulation effects in midbrain primary astrocytes. Our results showed that both icariin and icaritin significantly inhibited LPS-induced mRNA expressions of tumor necrosis factor (TNF-α) and interleukin-1β (IL-1β). Pre-treatment with IGF-1 receptor antagonist JB-1 could significantly block the anti-inflammatory effects of icariin and icaritin on LPS-induced up-regulations of TNF-α, IL-1β, cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). Under basal conditions of astrocytes, icariin and icaritin treatment alone increased the phosphorylation of ERK1/2 and AKT, which could be blocked by JB-1. Moreover, the mRNA expressions of glutamate transptor-1 (GLT-1) and glutamate-aspartate transporter (GLAST) could be up-regulated by icariin and icaritin in a time-dependent manner via IGF-1 receptor. Taken together, our results suggest for the first time that both icariin and icaritin exert regulatory effects in astrocytes under basal conditions and after an inflammatory challenge via IGF-1 receptor signaling pathway.

A comparative study on the in vitro and in vivo antitumor efficacy of icaritin and hydrous icaritin nanorods

Icaritin (ICT) and hydrous icaritin (HICT) are two similar flavonoids compounds isolated from Epimedium Genus. This is the first comparative study on their in vitro and in vivo antitumor effects. Nanorods (NRs) were prepared for ICT and HICT by anti-solvent precipitation method using D-alpha tocopherol acid polyethylene glycol succinate (TPGS) as a stabilizer. The prepared ICT-NRs and HICT-NRs had similar diameter (155.5 nm and 201.7 nm), high drug loading content (43.30 ± 0.22% and 41.08 ± 0.19%), excellent stability and a similar sustaining drug release manner. Nanorods improved the in vitro toxicity against 4 different cancer cells in contrast to free ICT or free HICT; however, no significant difference was observed in this regard between ICT-NRs and HICT NRs. In the in vivo study on the anticancer efficacy on MCF-7 and PLC/PRE/5 tumor-bearing mice model, HICR-NRs displayed certain advantage over ICT NRs with higher tumor inhibition rate.

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.

Prenylated flavonoids in foods and their applications on cancer prevention

Functional foods play an important role in health care and chronic diseases prevention, particularly cancer. Prenylated flavonoids are presented in many food resources. They are recognized as neutraceuticals due to their diverse health benefits. Up to now, more than 1000 prenylated flavonoids have been identified in plants. Their food resources are reviewed in this paper. Due to the good safety and cancer prevention effect of prenylated flavonoids, this paper reviews the cancer prevention activities and mechanisms reported in last decade. The structure-activity relationship is discussed. Due to the limited availability in nature, the heterologously biosynthetic technique of prenylated flavonoids is discussed in this review. Inclusion of dietary prenylated flavonoids into human diet is highly desirable. This paper combines the up-to-date information and give a clear image regarding prenylated flavonoids as neutraceuticals.

Systems pharmacology dissection of Epimedium targeting tumor microenvironment to enhance cytotoxic T lymphocyte responses in lung cancer

The clinical notably success of immunotherapy fosters an enthusiasm in developing drugs by enhancing antitumor immunity in the tumor microenvironment (TME). Epimedium, is a promising herbal medicine for tumor immunotherapy due to the pharmacological actions in immunological function modulation and antitumor. Here, we developed a novel systems pharmacology strategy to explore the polypharmacology mechanism of Epimedium involving in targeting TME of non-small cell lung cancer (NSCLC). This strategy integrates the active compounds screening, target predicting, network pharmacology analysis and onco-immune interacting to predict the potential active compounds that trigger the antitumor immunity. Icaritin (ICT), a major active ingredient of Epimedium, was predicted to have good drug-like properties and target immune microenvironment in NSCLC via regulating multiple targets and pathways. Then, we evidenced that the ICT effectively inhibited tumor growth in LLC tumor-bearing mice and increases the infiltration of CD8+ T cells in TME. In addition, we demonstrated that ICT promotes infiltration of CD8⁺ T cells in TME by downregulating the immunosuppressive cytokine (TNF-α, IL10, IL6) and upregulating chemotaxis (CXCL9 and CXCL10). Overall, the systems pharmacology strategy offers an important paradigm to understand the mechanism of polypharmacology of natural products targeting TME.

Selective alkylation of β-anhydroicaritine and their biological evaluation on anticancer

A convenient and selective alkylation of icaritin has been developed. The methodology involved initial formation of β-anhydroicaritine (3) under acidic conditions followed by selective methylation at the C-3 position and then alkylation at C-5 position. Several alkylated β-anhydroicaritine derivatives were synthesised using this methodology. These newly synthesised derivatives, especially the compounds 5b, 5c and 5j, significantly suppressed cell proliferation when tested against cancer cell lines in vitro. Compound 5j (R = Bn) exhibited a competitive inhibition against MCF7 in vivo compared to tamoxifen.

STAT3 transcription factor as target for anti-cancer therapy

STATs constitute a large family of transcription activators and transducers of signals that have an important role in many cell functions as regulation of proliferation and differentiation of the cell also regulation of apoptosis and angiogenesis. STAT3 as a member of that family, recently was discovered to have a vital role in progression of different types of cancers. The activation of STAT3 was observed to regulate multiple gene functions during cancer-like cell proliferation, differentiation, apoptosis, metastasis, inflammation, immunity, cell survival, and angiogenesis. The inhibition of STAT3 activation has been an important target for cancer therapy. Inhibitors of STAT3 have been used for a long time for treatment of many types of cancers like leukemia, melanoma, colon, and renal cancer. In this review article, we summarize and discuss different drugs inhibiting the action of STAT3 and used in treatment of different types of cancer.

Natural and herbal compounds targeting breast cancer, a review based on cancer stem cells

Cancer stem cells (CSCs) are known as the major reason for therapy resistance. Recently, natural herbal compounds are suggested to have a significant role in inhibiting the breast cancer stem cells (BCSCs). The aim of this study was to explore the effective natural herbal compounds against BCSCs.This review article was designed based on the BCSCs, mechanisms of therapy resistance and natural herbal compounds effective to inhibit their activity. Therefore, Science direct, PubMed and Scopus databases were explored and related original articles were investigated from 2010 to 2019. BCSCs use different mechanisms including special membrane transporters, anti-apoptotic, pro-survival, and self-renewal- related signaling pathways. Natural herbal compounds could disturb these mechanisms, therefore may inhibit or eradicate the BCSCs. Studies show that a broad range of plants, either as a food or medicine, contain anti-cancer agents that phenolic components and their different derivatives share a large quantity. Natural herbal compounds play a pivotal role in the eradication of BCSCs, through the inhibition of biological activities and induction of apoptosis. Although it is necessary to conduct more clinical investigation.

MLPH Accelerates the Epithelial-Mesenchymal Transition in Prostate Cancer

INTRODUCTION

Prostate cancer (PC) is the second greatest cause of cancer deaths globally. PC presents a poor prognosis once it metastasizes. There is considerable proof of vital epithelial-mesenchymal transition (EMT) functionality in PC metastasis. Previous studies revealed that melanophilin (MLPH) is associated with PC; however, its role in PC remains poorly understood.

METHODS

Bioinformatics analyses were performed. The cellular responses to MLPH knockdown were examined in HCC cell lines via wound healing assay, migration and invasion assay, Western blotting.

RESULTS

Analysis of the PROGgeneV2 database revealed that high MLPH expression might indicate poor overall survival. MLPH knockdown reduced PC cell migration, proliferation, and invasion. MLPH downregulation in vivo resulted in a lower growth rate and fewer metastatic nodules in lung tissues. Furthermore, MLPH knockdown recovered downregulated expression of the mesenchymal marker N-cadherin and the epithelial marker E-cadherin following a decrease in β-catenin.

CONCLUSION

These results indicate that progression of PC is stimulated via MLPH-dependent initiation of the EMT.

Induction of ROS and DNA damage-dependent senescence by icaritin contributes to its antitumor activity in hepatocellular carcinoma cells

Context: Icaritin (ICT), a prenylflavonoid derivative extracted from the Epimedium (Berberidaceae) genus, has been identified to exhibit antitumor effect in hepatocellular carcinoma (HCC) cells by inducing apoptosis. However, its effect on cellular senescence has not been elucidated. Objective: To investigate the mechanism for low concentrations of ICT exerting antitumor activity through induction of cellular senescence. Materials and methods: Human HepG2 and Huh7 cells were treated with low concentrations of ICT (1 and 2 μM) once per day for a week. Cellular senescence was evaluated through cell viability and senescence-associated-β-galactosidase activity. Cell cycle distribution and ROS levels were measured with flow cytometry. Gene expression was detected using qRT-PCR and western blotting. Fluorescent punctuates formation of γH2AX was analyzed by immunofluorescence. Results: ICT (1 and 2 μM) promoted cellular senescence in HepG2 and Huh7 cells, as observed by enlarged and flattened morphology and increased senescence-associated-β-galactosidase activity (∼7-8-fold and ∼11-12-fold of vehicle controls, respectively), accompanied by significant cell cycle arrest and decrease in DNA synthesis. Mechanistically, ICT-induced senescence occurred through accumulation of ROS (∼1.3-fold and ∼1.8-fold of vehicle controls in response to 1 and 2 μM ICT, respectively), which further resulted in DNA damage response, as evidenced by strong induction of γH2AX through immunofluorescence and western blotting assays. Pharmacological inhibition of ROS production with N-acetylcysteine attenuated ICT-induced γH2AX and senescence-associated-β-galactosidase activity (∼0.28-0.30-fold decrease, p < 0.05). Discussion and conclusions: Induction of cellular senescence by ICT defines a novel anticancer mechanism of ICT and provides a rationale for generalizing the study design to a broader study population to further developing ICT as a novel therapeutic agent for treatment of HCC.

Pharmacokinetics and metabolism of icaritin in rats by UPLC-MS/MS

Icaritin (ICT) has distinct bioactivities, especially known for its beneficial effects on bone-related degenerative disorders; however, its pharmacokinetic properties remain unknown. A novel developed UPLC-MS/MS method for the determination of ICT and its main metabolite glucuronidated icaritin (GICT) was firstly applied to pharmacokinetic and metabolism studies of ICT in female rats, which were intraperitoneally given 40 mg/kg ICT. Following the protein precipitation of plasma samples with acetonitrile, ICT and GICT were separated on a C18 column using gradient elution mode and quantified in the multiple reaction monitoring mode. The linearities were acceptable for ICT (r = 0.9960) and GICT (r = 0.9968), and the lower limit of quantification values was 0.5 and 5 ng/ml, respectively. The accuracy fell in the range of 92.0%-103.1% and precisions were within 9.5%. Good linearity, accuracy, precision, and recovery were achieved for the UPLC-MS/MS method. ICT was predominantly and rapidly biotransformed to GICT which was slowly eliminated in vivo with a terminal half-life value of 4.51 hr. Pharmacokinetics of pure ICT eliminated biotransformation interference of Epimedium extract and disclosed genuine pharmacokinetic manner of ICT, as well as firstly elucidated low concentration and bioavailability of ICT in rat plasma.

Anticancer effect of icaritin on prostate cancer via regulating miR-381-3p and its target gene UBE2C

Prostate cancer (PCa) is one of the most common health-related issues in the male individuals of western countries. Icaritin (ICT) is a traditional Chinese herbal medicine that exhibits antitumor efficacy in variety of cancers including PCa. However, the precise function and detailed molecular mechanism of ICT in the regression of PCa remain unclear. Ubiquitin-conjugating enzyme E2C (UBE2C) is an anaphase-promoting complex/cyclosome (APC/C)-specific ubiquitin conjugating enzyme, which acts as an oncogene in PCa progression. The function of ICT in PCa was investigated in transgenic adenocarcinoma mouse prostate (TRAMP) mice using survival analysis, hematoxylin and eosin (HE) staining, TUNEL assay, and immunohistochemistry and in human PCa cell lines using various molecular techniques and functional assays including plasmid construction and transfection. Bioinformatic analyses were performed to identify the interaction between miRNA and UBE2C via the TargetScan algorithm. We demonstrated that ICT inhibited the development and progression of PCa in TRAMP mice by improving the survival rate and tumor differentiation. Furthermore, we found that ICT could significantly inhibit cell proliferation and invasion and induce apoptosis in PCa cells. Consistently, downregulation of UBE2C suppressed the proliferation and invasion of PCa cells. Moreover, a luciferase reporter assay confirmed that UBE2C was a direct target of miR-381-3p. Meanwhile, ICT simultaneously downregulated UBE2C expression and upregulated miR-381-3p levels in human PCa cells. Altogether, our findings provide a strong rationale for the clinical application of ICT as a potential oncotherapeutic agent against PCa via a novel molecular mechanism of regulating the miR-381-3p/UBE2C pathway.

Ampelopsin inhibits human glioma through inducing apoptosis and autophagy dependent on ROS generation and JNK pathway

Glioma is the most common form of malignant brain cancer with high mortality rate in human. Therefore, finding effective therapeutic strategy and revealing the underlying molecular mechanism is necessary. Ampelopsin (Amp), an effective component of the traditional Chinese herb of Ampelopsis grossedentata, is reported to have important biological properties, including anti-inflammatory, anti-cancer, and anti-oxidant activity; however, its effects on human glioma are poorly understood. Here, the in vitro and in vivo study was performed to investigate the anti-glioma ability of Ampelopsin. Human glioma cell lines of U251 and A172 were treated with Ampelopsin (0, 25, 50, and 100 uM) for 24 h, followed by various analysis. And human glioma xenograft models were established by injecting U251, accompanied with administration of Ampelopsin at 50 and 100 mg/kg to confirm the anti-cancer role of Ampelopsin. We found that Ampelopsin could suppress the glioma cell proliferation by modulating G1 and S phase arrest. Incubation with Ampelopsin led to the activity of Caspase-8, Caspase-9, Caspase-3 and poly (ADP-ribose) polymerases (PARP), indicating that Ampelopsin induced apoptotic response via both intrinsic and extrinsic signaling pathways. Additionally, autophagy was also observed in Ampelopsin-treated cancer cells, which is evidenced by autophagosome formation and LC3B-II accumulation. Ampelopsin-caused cancer cell death was obviously regained by apoptosis inhibitors. Further, Ampelopsin activated c-Jun N-terminal protein kinase (JNK) expression and enhanced reactive oxygen species (ROS) generation. Suppressing JNK markedly ameliorated Ampelopsin-induced apoptosis and autophagy, and ROS scavenger exhibited similar results. In vivo, Ampelopsin inhibited tumor growth and progression in mouse xenograft models. In conclusion, our findings indicated that Ampelopsin led to G1 and S phase arrest, triggered apoptosis and autophagy through potentiating ROS generation and JNK activation in human glioma cells. Thus, Ampelopsin might be a promising candidate against human glioma.

Natural products: An upcoming therapeutic approach to cancer

Cancer is one of the leading causes of death across the world. Different environmental and anthropogenic factors initiate mutations in different functional genes of growth factors and their receptors, anti-apoptotic proteins, self-renewal developmental proteins, tumor suppressors, transcription factors, etc. This phenomenon leads to altered protein homeostasis of the cell which in turn induces cancer initiation, development, progression and survival. From ancient times various natural products have been used as traditional medicine against different diseases. Natural products are readily applicable, inexpensive, accessible and acceptable therapeutic approach with minimum cytotoxicity. As most of the target-specific anticancer drugs failed to achieve the expected result so far, new multi-targeted therapies using natural products have become significant. In this review, we have summarized the efficacy of different natural compounds against cancer. They are capable of modulating cancer microenvironment and diverse cell signaling cascades; thus playing a major role in combating cancer. These compounds are found to be effective against several signaling pathways, mainly cell death pathways (apoptosis and autophagy) and embryonic developmental pathways (Notch pathway, Wnt pathway and Hedgehog pathway). This review article is expected to be helpful in understanding the recent progress of natural product research for the development of anticancer drug.

Icaritin: A Novel Natural Candidate for Hematological Malignancies Therapy

Hematological malignancies including leukemia and lymphoma can severely impact human health. With the current therapies combined with chemotherapy, stem cell transplantation, radiotherapy, and immunotherapy, the prognosis of hematologic malignancies improved significantly. However, most hematological malignancies are still incurable. Therefore, research for novel treatment options was continuing with the natural product as one source. Icaritin is a compound extracted from a traditional Chinese herb, Epimedium Genus, and demonstrated an antitumor effect in various neoplasms including hematological malignancies such as leukemia, lymphoma, and multiple myeloma. In hematological malignancies, icaritin showed multiple cytotoxic effects to induce apoptosis, arrest the cell cycle, inhibit proliferation, promote differentiation, restrict metastasis and infiltration, and suppress the oncogenic virus. The proved underlying mechanisms of the cytotoxic effects of icaritin are different in various cell types of hematological malignancies but associated with the critical cell signal pathway, including PI3K/Akt, JAK/STAT3, and MAPK/ERK/JNK. Although the primary target of icaritin is still unspecified, the existing evidence indicates that icaritin is a potential novel therapeutic agent for neoplasms as with hematological malignancies. Here, in the field of hematology, we reviewed the reported activity of icaritin in hematologic malignancies and the underlying mechanisms and recognized icaritin as a candidate for therapy of hematological malignancies.

Reactive oxygen species induced by icaritin promote DNA strand breaks and apoptosis in human cervical cancer cells

Increased production of reactive oxygen species (ROS) is a distinct feature of various types of cancer. ROS drive tumor progression and render cancer cells vulnerable to additional oxidative insult. The various natural herb compounds have been shown to induce additional production of ROS in cancer cells, although the physiological implications of ROS under these conditions are not fully determined. In the present study, icaritin, a natural compound derived from the medicinal plants Epimedium, was demonstrated to potently suppresses the proliferation of human HeLa and SiHa cervical cancer cells, without similar affects on non-cancerous CCD-1095Sk fibroblasts and 293 cells, as measured by MTT and colony formation assays. Icaritin treatment caused a rapid increase in ROS in HeLa and SiHa cells, which was followed by a prominent increase in the number of DNA strand breaks. Consequently, the levels of the pro-apoptotic protein Bax and activated caspase 3 and 9 enzymes were increased, while the levels of the anti-apoptotic proteins Bcl-2 and XIAP were downregulated. These protein expression changes were accompanied by marked induction of apoptosis in icaritin-treated cancer cells. The results suggested that the icaritin-induced ROS overload promoted cancer cell death via induction of extensive oxidative DNA damage, which subsequently resulted in large numbers of DNA strand breaks and the activation of the intrinsic apoptotic pathway.

Icariin reduces human colon carcinoma cell growth and metastasis by enhancing p53 activities

Icariin has been reported to possess high anticancer activity. Colon carcinoma is one of the leading causes of cancer-related mortality worldwide. Here, the anticancer activity of icariin against HCT116 colon carcinoma cells and the possible underlying mechanism were studied. The trypan blue staining assay, wound healing assay, clonogenic assay, CCK-8 assay, and Annexin V-FITC/PI double staining method were carried out to determine the changes of HCT116 cell growth and migration. mRNA and protein expressions were determined by quantitative real-time PCR and western blot, respectively. Moreover, small interfering RNA (siRNA) plasmid was used to examine the role of p53 in icariin-induced apoptosis in HCT116 cells. Icariin significantly suppressed colon carcinoma HCT116 cells by decreasing migration and viability, and simultaneously promoting apoptosis. Icariin exerted the anti-tumor effect in a dose-dependent manner by up-regulating p53. During treatment of icariin, p-p53, p21, and Bax levels increased, and Bcl-2 level decreased. Short time treatment with icariin induced DNA damage in HCT116 cells. Furthermore, the cytotoxicity of icariin was decreased after p53 knockdown or by using caspase inhibitors. p53 was involved in activities of caspase-9 and caspase-3. Icariin repressed colon carcinoma cell line HCT116 by enhancing p53 expression and activating p53 functions possibly through Bcl-2/Bax imbalance and caspase-9 and -3 regulation. Icariin treatment also induced DNA damage in HCT116 cells.

Icaritin induces ovarian cancer cell apoptosis through activation of p53 and inhibition of Akt/mTOR pathway

AIMS

Ovarian cancer (OC) has the highest mortality rate of all gynecological cancers. Currently, the first-line OC treatment consists of cytoreductive surgery and platinum-based chemotherapy. However, most patients develop chemoresistance after the first-line treatment limits the success of treatment. Therefore, there is an urgent need to identify effective therapeutic agents.

MAIN METHODS

Cell viabilities were detected by MTS assay; Annexin V-FITC/PI assay and western blotting assay were performed to analyze the apoptotic cells in vitro; An immunofluorescence assay was performed to analyze the TUNEL⁺ apoptotic cells in vivo; Patient-derived xenografts were established to test the in vivo antitumor effects; The key proteins of p53, caspase-mediated apoptotic pathway and Akt/mTOR pathway were detected by Western blotting.

KEY FINDINGS

Icaritin, a prenylflavonoid derivative from Epimedium Genus, inhibited the proliferation of drug-sensitive OC cells (OV2008 and C13*) and cisplatin resistant OC cells A2780cp. Icaritin induced OC cell apoptosis in vitro, as indicated by the increase of Annexin V⁺/PI⁺ apoptotic cells analyzed with flow cytometry, and the cleavage of caspase 9, caspase 3 and poly-ADP-ribose polymerase (PARP) detected with western blotting. Icaritin also inhibited tumor growth and induced OC cells apoptosis in patient-derived xenografts, as indicated by the tumor growth delay and increase of TUNEL-positive cells in tumor tissues. The icaritin-induced OC cell apoptosis may be associated with the activation of p53 and the suppression of Akt/mTOR pathway.

SIGNIFICANCE

This study sheds light on the underlying mechanisms of antitumor effect of icaritin, and warrants clinical trial for treatment of OC.

Iciartin, a novel FASN inhibitor, exerts anti-melanoma activities through IGF-1R/STAT3 signaling

Icaritin (IT) is a flavonoid isolated from Herba Epimedii. In this study, we evaluated the anti-melanoma activities of IT, and determined its cytotoxic mechanism. We found that IT exerted cytotoxicity to melanoma cells. Furthermore, IT induced melanoma cell apoptosis, which was accompanied with PARP cleavage. Mechanistically, IT suppressed p-STAT3 (tyr705) level in parallel with increases of p-STAT3 (ser727), p-ERK and p-AKT. IT significantly inhibited STAT3 nuclear translocation and reduced the levels of STAT3 -targeted genes. IT also inhibited IGF-1-induced STAT3 activation through down-regulation of total IGF-1R level. No dramatic changes in IGF-1R mRNA levels were observed in IT-treated cells, suggesting that IT acted primarily at a post-transcriptional level. Using molecular docking analysis, IT was identified as a novel fatty acid synthase (FASN) inhibitor. We found that IT reduced the level of total IGF-1R via FASN inhibition. In summary, we reported that IT exerted anti-melanoma activities, and these effects were partially due to inhibition of FASN/IGF-1R/STAT3 signaling.

Improvement of icaritin on hematopoietic function in cyclophosphamide-induced myelosuppression mice

CONTEXT

Icaritin (ICT), an intestinal metabolite of prenylflavonoids from Herba Epimedii, has been known to regulate many immune processes. But there are little studies of ICT on hematopoietic function.

OBJECTIVE

We aimed to investigate the improvement of ICT on hematopoietic function in cyclophosphamide (CTX)-induced myelosuppression mice.

METHODS

Mice were given CTX (50 mg/kg) by i.p. for five days to produce bone marrow depression model. 48 h after last treated with CTX, ICT was administrated at 10 mg/kg/d by p.o. for five days. Blood routine, body weight, thymus index and spleen index were tested. The bone marrow hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs), cell cycle and apoptosis of HSCs were quantified by flow cytometry. The bone marrow nucleated cells were counted by an automated cell counter. The histology of femoral bone was examined by Haemotoxylin and Eosin (H&E) staining. Serum erythropoietin (EPO), granulocyte colony-stimulating factor (G-CSF) and thyroperoxidase (TPO) were tested by ELISA kit.

RESULTS

ICT (10 mg/kg) protected against CTX-induced myelosuppression, is evidenced by increased blood cell numbers, body weight, thymus index, spleen index and improved femoral bone morphology. ICT corrected the reduction of bone marrow HSCs and HPCs, promoted bone marrow HSCs entering the proliferative cycle phase and prevented cells proceeding to the apoptosis phase. Meanwhile, ICT increased the release of G-CSF and TPO in model mice serum.

CONCLUSION

These results demonstrated that ICT improves myelosuppression by improving bone marrow hematopoietic microenvironment, promoting the proliferation and differentiation of HSCs, inhibiting the apoptosis of HSCs and stimulating the expression of G-CSF and TPO.

Identification of sphingosine kinase 1 (SphK1) as a primary target of icaritin in hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is a highly aggressive neoplasm. We aim to explore the anti-HCC activity by a natural prenylflavonoid icaritin. Icaritin was cytotoxic and pro-apoptotic when added to established (HepG2, KYN-2 and Huh-7 lines) and primary human HCC cells. At the signaling level, icaritin inhibited sphingosine kinase 1 (SphK1) activity in HCC cells, which led to pro-apoptotic ceramide production and JNK1 activation. SphK1 inhibition or silence (by shRNA/microRNA) mimicked icaritin-mediated cytotoxicity, and almost nullified icaritin's activity in HepG2 cells. Reversely, exogenous over-expression of SphK1 sensitized icaritin-induced HepG2 cell apoptosis. In vivo, oral administration of icaritin dramatically inhibited HepG2 xenograft growth in SCID mice. Further, SphK1 activity in icaritin-treated tumors was largely inhibited. In summary, icaritin exerts potent anti-HCC activity in vitro and in vivo. SphK1 inhibition could be the primary mechanism of its actions in HCC cells.

Antitumoral action of icaritin in LNCaP prostate cancer cells by regulating PEA3/HER2/AR signaling

Human epidermal growth factor receptor type 2 (HER2) and androgen receptor (AR) are critical factors for prostate cancer (PCa) progression. These factors regulate tumor cell survival and proliferation, and remain as crucial drivers of castration-resistant PCa progression. Icaritin (ICT) is a prenyl flavonoid derived from the Epimedium genus, which has many biological and pharmacological effects. Using androgen-sensitive human prostate carcinoma LNCaP cell lines, we found that 35 μg/ml of ICT could inhibit more than 50% of cell proliferation, induce cell apoptosis, and lead to a strong G1 phase arrest by targeting cyclin-related proteins and suppressing the ability of cell invasion. Moreover, ICT exerts its potent anticancer efficacy by inducing polyomavirus enhancer activator 3 (PEA3) to inhibit the aberrantly activated HER2/AR signaling. In addition, after PEA3 expression was silenced by specific small-interference RNA, we found that both the ICT-inhibited effect on LNCaP cell proliferation and the ICT-induced cell apoptosis rate decreased. These results provide alternative mechanisms for the antitumor actions of ICT, indicating that ICT might be a promising therapeutic agent, as well as a preventive agent, for hormone therapy-resistant PCa.

AMPK-autophagy inhibition sensitizes icaritin-induced anti-colorectal cancer cell activity

The current research studied the potential effect of autophagy on icaritin-induced anti-colorectal cancer (CRC) cell activity. Treatment of icaritin in both primary and established (HT-29) CRC cells induced feedback activation of autophagy, evidenced by p62 degradation, Beclin-1 and autophagy-related gene-5 (ATG-5) upregulation, as well as light chain 3B (LC3B)-GFP puncta formation. Pharmacological inhibiting of autophagy dramatically potentiated icaritin-induced CRC cell death and apoptosis. Meanwhile, shRNA-mediated knockdown of Beclin-1 or ATG-5 also sensitized icaritin-induced CRC cell death and apoptosis. Icaritin activated AMP-activated protein kinase (AMPK) signaling in CRC cells, functioning as the upstream signaling for autophagy activation. shRNA/siRNA-mediated knockdown of AMPKα1inhibited icaritin-induced autophagy activation, but exacerbated CRC cell death. On the other hand, the AMPK activator compound 13 (C13) or the autophagy activator MHY1485 attenuated icaritin-induced cytotoxicity. In nude mice, icaritin (oral administration)-induced HT-29 tumor growth inhibition was potentiated when combined with AMPKα1 shRNA knockdown in tumors. We conclude that feedback activation of AMPK-autophagy pathway could be a primary resistance factor of icaritin.

Icaritin induces MC3T3-E1 subclone14 cell differentiation through estrogen receptor-mediated ERK1/2 and p38 signaling activation

Icaritin (ICT), a hydrolytic product of icariin from the genus Epimedium, has many indicated pharmacological and biological activities. Several studies have shown that ICT has potential osteoprotective effects, including stimulation of osteoblast differentiation and inhibition of osteoclast differentiation. However, the molecular mechanism for this anabolic action of ICT remains largely unknown. Here, we found that ICT could enhance MC3T3-E1 subclone 14 preosteoblastic cell differentiation associated with increased mRNA levels and protein expression of the differentiation markers alkaline phosphatase (ALP), type 1 collagen (COL1), osteocalcin (OC), osteoponin (OPN) and runt-related transcription factor 2 (RUNX2), and improved mineralization, confirmed by bone nodule formation and collagen synthesis. To characterize the underlying mechanisms, we examined the effect of ICT on estrogen receptor (ER) and mitogen-activated protein kinase (MAPK) signaling. ICT treatment induced p38 kinase and extracellular signal-regulated kinase 1/2 (ERK1/2) activation, but it demonstrated at the same time point no effect on activation of c-Jun N-terminal kinase (JNK). ER antagonist ICI182780, p38 antagonist SB203580 and ERK1/2 antagonist PD98059 markedly inhibited the ICT-induced the mRNA expression of ALP, COL1, OC and OPN. ICI182780 attenuated the ICT-induced phosphorylation of p38 and ERK1/2. These observations indicate a potential mechanism of osteogenic effects of ICT involving the ERK1/2 and p38 pathway activation through the ER.

Estrogen receptor-α36 is involved in icaritin induced growth inhibition of triple-negative breast cancer cells

A sub-class of ER-negative breast cancer that is negative for ER, PR and HER2 expression known as triple-negative breast cancer (TNBC) is highly malignant and lacks effective treatment. Recently, it has been reported that an isoform of estrogen receptor-alpha ER-α36 is expressed and plays a critical role in development of TNBC. ER-α36 forms a positive regulatory loop with epidermal growth factor receptor (EGFR), which promotes malignant growth of TNBC cells. Thus, ER-α36 has been proposed as an important target for development of novel drugs for TNBC. In this study, we evaluated the effects of icaritin, a prenylflavonoid derivant purified from Epimedium Genus, on growth of TNBC cells and examined the possible underlying mechanisms. Our study demonstrated that icartin decreased both ER-α36 and EGFR protein expression, and induced apoptosis in TNBC MDA-MB-231 and MDA-MB-453 cells. We also found that icaritin inhibited ER-α36-mediated MAPK/ERK pathway and cyclin D1 induction by estrogen. Our results thus indicated that icaritin has a potential to be developed into a novel therapeutic agent for human TNBC.