Icariside II in NSCLC and COVID-19: Network pharmacology and molecular docking study.

BACKGROUND: Patients with non-small cell lung cancer (NSCLC) are susceptible to coronavirus disease-2019 (COVID-19), but current treatments are limited. Icariside II (IS), a flavonoid compound derived from the plant epimedin, showed anti-cancer,anti-inflammation and immunoregulation effects. The present study aimed to evaluate the possible effect and underlying mechanisms of IS on NSCLC patients with COVID-19 (NSCLC/COVID-19). METHODS: NSCLC/COVID-19 targets were defined as the common targets of NSCLC (collected from The Cancer Genome Atlas database) and COVID-19 targets (collected from disease database of Genecards, OMIM, and NCBI). The correlations of NSCLC/COVID-19 targets and survival rates in patients with NSCLC were analyzed using the survival R package. Prognostic analyses were performed using univariate and multivariate Cox proportional hazards regression models. Furthermore, the targets in IS treatment of NSCLC/COVID-19 were defined as the overlapping targets of IS (predicted from drug database of TMSCP, HERBs, SwissTarget Prediction) and NSCLC/COVID-19 targets. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis of these treatment targets were performed aiming to understand the biological process, cellular component, molecular function and signaling pathway. The hub targets were analyzed by a protein-protein interaction network and the binding capacity with IS was characterized by molecular docking. RESULTS: The hub targets for IS in the treatment of NSCLC/COVID-19 includes F2, SELE, MMP1, MMP2, AGTR1 and AGTR2, and the molecular docking results showed that the above target proteins had a good binding degree to IS. Network pharmacology showed that IS might affect the leucocytes migration, inflammation response and active oxygen species metabolic process, as well as regulate the interleukin-17, tumor necrosus factor and hypoxia-inducible factor-1 signaling pathway in NSCLC/COVID-19. CONCLUSIONS: IS may enhance the therapeutic efficacy of current clinical anti-inflammatory and anti-cancer therapy to benefit patients with NSCLC combined with COVID-19.

Icariside II prevents kidney fibrosis development in chronic kidney disease by promoting fatty acid oxidation.

Renal interstitial fibrosis (RIF) is the main pathological basis for the progression of chronic kidney disease (CKD), however, effective interventions are limited. Here, we investigated the effect of Icariside II (ICA-II) on RIF and explored the underlying mechanisms. Rats receiving 5/6 ablation and infarction (A/I) surgery were gavaged with ICA-II (5 or 10 mg/kg) for 8 weeks. In vitro, TGF-ß1-stimulated NRK-52E cells were treated with ICA-II and (or) oleic acid, etomoxir, ranolazine, fenofibrate, and GW6471. The effects of ICA-II on RIF, fatty acid oxidation, lipid deposition, and mitochondrial function were determined by immunoblotting, Oil red O staining, colorimetric, and fluorometric assays. Using adeno-associated virus injection and co-culture methods, we further determined mechanisms of ICA-II anti-RIF. ICA-II ameliorated the fibrotic responses in vivo and in vitro. RNA-seq analysis indicated that ICA-II regulated fatty acid degradation and PPAR pathway in 5/6 (A/I) kidneys. ICA-II attenuated lipid accumulation and up-regulated expression of PPARα, CPT-1α, Acaa2, and Acadsb proteins in vivo and in vitro. Compared to ICA-II treatment, ICA-II combined with Etomoxir exacerbated mitochondrial dysfunction and fibrotic responses in TGF-ß-treated NRK-52E cells. Importantly, we determined that ICA-II improved lipid metabolism, fatty acid oxidation, mitochondrial function, and RIF by restoring PPARα. Co-culture revealed that ICA-II decreased the expression of Fibronectin, Collagen-I, α-SMA, and PCNA proteins in NRK-49F cells by restoring PPARα of renal tubular cells. ICA-II may serve as a promising therapeutic agent for RIF in 5/6 (A/I) rats, which may be important for the prevention and treatment of CKD.

Therapeutic effects of icariin and icariside II on diabetes mellitus and its complications.

Diabetes mellitus (DM) is a global health issue in the twenty-first century, and there are numerous challenges in preventing and alleviating its chronic complications. The herb Epimedium has beneficial therapeutic effects on various human diseases, including DM. Its major flavonoid component, icariin, has significant anti-DM activity and may help improve pancreatic ß-cell dysfunction and insulin resistance. Furthermore, preclinical evidence has shown that icariin and its in vivo bioactive form, icariside II, have preventive and therapeutic effects on several diabetic complications, including diabetic cardiomyopathy, diabetic vascular endothelial disorder, diabetic nephropathy, and diabetic erectile dysfunction. In this review, we present the general and toxicological information concerning icariin and icariside II and review the anti-DM effects of icariin from a molecular perspective. Additionally, we discuss the potential benefits of icariin and icariside II on the important pathological mechanisms of various diabetic complications. Despite positive preclinical evidence, additional investigations are needed before relevant clinical studies can be conducted. Therefore, we conclude with suggestions for future research. Hopefully, this review will provide a comprehensive molecular perspective for future research and product development related to icariin and icariside II in treating DM and diabetic complications.

Icariside II suppresses ferroptosis to protect against MPP+-Induced Parkinson's disease through Keap1/Nrf2/GPX4 signaling.

Parkinson's disease (PD) is recognized as a degenerative and debilitating neurodegenerative disorder. The novel protective role of icariside II (ICS II) as a plant-derived flavonoid compound in neurodegenerative diseases has aroused much attention. Herein, the definite impacts of ICS II on the process of PD and the relevant action mechanism were studied. Human neuroblastoma SK-N-SH cells were challenged with 1-methyl-4-phenylpyridinium ion (MPP+) to construct the PD cell model. MTT assay and flow cytometry analysis, respectively, appraised cell viability and apoptosis. Caspase 3 Activity Assay examined caspase 3 activity. Corresponding kits examined oxidative stress levels. BODIPY 581/591 C11 assay evaluated lipid reactive oxygen species. Iron Assay Kit assessed iron content. Western blot tested the expression of apoptosis-, ferroptosis- and Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2)/glutathione peroxidase 4 (GPX4) signaling-associated proteins. Molecular docking verified the binding of ICS II with Keap1. The existing experimental results unveiled that ICS II elevated the viability whereas reduced the apoptosis, oxidative stress, and ferroptosis in MPP+-treated SK-N-SH cells in a concentration-dependent manner. Furthermore, ICS II declined Keap1 expression while raised Nrf2, heme oxygenase 1, and GPX4 expression. In addition, ICS II had a strong binding with Keap1 and Nrf2 inhibitor ML385 partially abolished the suppressive role of ICS II in MPP+-triggered apoptosis, oxidative stress, and ferroptosis in SK-N-SH cells. To summarize, ICS II might inhibit apoptosis, oxidative stress, and ferroptosis in the MPP+-stimulated PD cell model, which might be due to the activation of Keap1/Nrf2/GPX4 signaling.

Effects of Icariin and Its Metabolites on GPCR Regulation and MK-801-Induced Schizophrenia-Like Behaviors in Mice.

Icariin, a major bioactive compound found in the Epimedium genus, has been reported to exert protective effects against neurodegenerative disorders. In the current study, we aimed to investigate the regulatory effect of icariin and its active metabolites (icariside II and icaritin) against prime G-protein-coupled receptor targets, considering their association with neuronal disorders. Icariside II exhibited selective agonist activity towards the dopamine D3 receptor (D3R), with half-maximal effective concentrations of 13.29 µM. Additionally, they effectively inhibited the specific binding of radioligands to D3R. Molecular docking analysis revealed that icariside II potentially exerts its agonistic effect through hydrogen-bonding interaction with Asp110 of the D3R, accompanied by negative binding energy. Conversely, icaritin demonstrated selective antagonist effects on the muscarinic acetylcholine M2 receptor (M2R). Radioligand binding assay and molecular docking analysis identified icaritin as an orthosteric ligand for M2R. Furthermore, all three compounds, icariin and its two metabolites, successfully mitigated MK-801-induced schizophrenia-like symptoms, including deficits in prepulse inhibition and social interaction, in mice. In summary, these findings highlight the potential of icariin and its metabolites as promising lead structures for the discovery of new drugs targeting cognitive and neurodegenerative disorders.

Icariside II suppressed tumorigenesis by epigenetically regulating the circß-catenin-Wnt/ß-catenin axis in colorectal cancer.

Icariside II, a flavonol glycoside, one of the major components of Traditional Chinese Medicine Herba epimedii. In the present study, we found that Icariside II suppressed the proliferation of CRC by inducing cell cycle arrest and apoptosis in vitro and inhibited tumor growth in vivo. The further mechanism investigation showed that Icariside II suppressed the expression of ß-catenin and led to the functional inactivation of Wnt/ß-catenin signaling. Circß-catenin was considered as a promising candidate for mediating the tumorigenesis and the activation of Wnt/ß-catenin signaling in CRC cells. Furthermore, Icariside II has been proven to suppress the biogenesis of circß-catenin via epigenetically targeting DNA methyltransferases (DNMTs) to decrease global DNA methylation levels in CRC cells. Taken together, our results indicated that Icariside II suppressed tumorigenesis by epigenetically silencing the activation of circß-catenin-Wnt/ß-catenin axis in colorectal cancer. More importantly, the information gained from this study suggest that Icariside II may have great potential to be developed as a therapeutic drug for CRC patients.

Icariside II suppresses the tumorigenesis and development of ovarian cancer by regulating miR-144-3p/IGF2R axis.

Ovarian cancer is one of the three major gynecological malignancies. It has been reported that Icariside II was able to block the occurrence and development of ovarian cancer. However, the detailed mechanism by which Icariside II regulates the development of ovarian cancer is widely unknown. EdU staining and transwell assays were applied to detect the proliferation, migration, and invasion of ovarian cancer cells. Next, the relationship between miR-144-3p and IGF2R was verified by the dual-luciferase reporter assay. Moreover, in vivo animal model was constructed to verify the effect of Icariside II on the development of ovarian cancer. Icariside II notably inhibited the proliferation, migration, and invasion and induced the apoptosis of ovarian cancer cells. Additionally, Icariside II markedly increased the level of miR-144-3p in ovarian cancer cells. Moreover, IGF2R was targeted by miR-144-3p directly. Icariside II significantly decreased the expression of IGF2R and the phosphorylation level of AKT and mTOR in ovarian cancer cells, which were partially reversed by miR-144-3p inhibitor. Meanwhile, Icariside II remarkably promoted the autophagy of ovarian cancer cells, as confirmed by the increased expression of Beclin-1 and ATG-5 and decreased expression of p62; however, co-treatment with miR-144-3p inhibitor notably decreased autophagy. Furthermore, the result of animal study suggested Icariside II notably inhibited ovarian tumor growth as well. Collectively, Icariside II could suppress the tumorigenesis and development of ovarian cancer by promoting autophagy via miR-144-3p/IGF2R axis. These results may be beneficial for future studies on the use of Icariside II to treat ovarian cancer.

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.

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.

Icariside II attenuates eosinophils-induced airway inflammation and remodeling via inactivation of NF-κB and STAT3 in an asthma mouse model.

Asthma is a chronic inflammatory airway disease. Icariside II has been reported to exert anti-inflammatory effect in multiple human diseases. The present study aimed to investigate the effects and mechanisms of Icariside II on airway inflammation and remodeling in asthma. We established an asthma mouse model with ovalbumin (OVA) immunization. Histological analysis using H&E, PAS and Masson staining showed that administration of Icariside II attenuated OVA-induced airway inflammation and remodeling. Icariside II reduced the numbers of total white blood cells and eosinophils in bronchoalveolar lavage fluid (BALF). The levels of interleukin (IL)-4, IL-5, IL-13 and transforming growth factor (TGF)-ß1 in peripheral blood and the expression of α-smooth muscle actin (α-SMA), connective tissue growth factor (CTGF), eotaxin-1, CC-chemokine receptor-3 (CCR-3), Toll-like receptor (TLR)-2 and TLR-4 were significantly down-regulated in lung tissues of OVA-induced mouse model. These results suggested that Icariside II inhibited eosinophil activation and thus decreased eosinophils-induced airway inflammation and remodeling in asthma. Moreover, Icariside II suppressed TGF-ß1-induced cell proliferation, migration, and CTGF expression in airway smooth muscle cells (ASMCs). In both OVA-induced mouse model of asthma and TGF-ß1-induced ASMCs, Icariside II decreased IκBα degradation, nuclear translocation of NF-κB p65 and STAT3 phophorylation, indicating an inactivation of NF-κB and STAT3 in the presence of Icariside II. Therefore, we demonstrate that Icariside II attenuates eosinophils-induced airway inflammation and remodeling in asthmatic mice and inhibits TGF-ß1-induced cell proliferation and migration in ASMCs via suppressing NF-κB and STAT3 signalings.

Icariside II inhibits lipopolysaccharide-induced inflammation and amyloid production in rat astrocytes by regulating IKK/IκB/NF-κB/BACE1 signaling pathway.

ß-amyloid (Aß) is one of the inducing factors of astrocytes activation and neuroinflammation, and it is also a crucial factor for the development of Alzheimer's disease (AD). Icariside II (ICS II) is an active component isolated from a traditional Chinese herb Epimedium, which has shown to attnuate lipopolysaccharide (LPS)-induced neuroinflammation through regulation of NF-κB signaling pathway. In this study we investigated the effects of ICS II on LPS-induced astrocytes activation and Aß accumulation. Primary rat astrocytes were pretreated with ICS II (5, 10, and 20 µM) or dexamethasone (DXMS, 1 µM) for 1 h, thereafter, treated with LPS for another 24 h. We found that ICS II pretreatment dose dependently mitigated the levels of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1ß), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) in the astrocytes. Moreover, ICS II not only exerted the inhibitory effect on LPS-induced IκB-α degradation and NF-κB activation, but also decreased the levels of Aß1-40, Aß1-42, amyloid precursor protein (APP) and beta secretase 1 (BACE1) in the astrocytes. Interestingly, molecular docking revealed that ICS II might directly bind to BACE1. It is concluded that ICS II has potential value as a new therapeutic agent to treat neuroinflammation-related diseases, such as AD.

Icariside II attenuates cerebral ischemia/reperfusion-induced blood-brain barrier dysfunction in rats via regulating the balance of MMP9/TIMP1.

Cerebral ischemia/reperfusion (I/R) results in harmful consequences during ischemic stroke, especially the disruption of the blood-brain barrier (BBB), which leads to severe hemorrhagic transformation through aggravation of edema and brain hemorrhage. Our previous study demonstrated that icariside II (ICS II), which is derived from Herba Epimedii, attenuates cerebral I/R injury by inhibiting the GSK-3ß-mediated activation of autophagy both in vitro and in vivo. However, the effect of ICS II on the BBB remains unclear. Thus, in this study, we investigated the regulation of BBB integrity by ICS II after cerebral I/R injury and further explored the underlying mechanism in rats. Cerebral I/R injury was induced by middle cerebral artery occlusion (MCAO), and the treatment groups were administered ICS II at a dose of 16 mg/kg by gavage twice a day for 3 days. The results showed that ICS II effectively prevented BBB disruption, as evidenced by Evans Blue staining. Moreover, ICS II not only significantly reduced the expression of MMP2/9 but also increased TIMP1 and tight junction protein (occludin, claudin 5, and ZO 1) expression. Intriguingly, ICS II may directly bind to both MMP2 and MMP9, as evidenced by molecular docking. In addition, ICS II also inhibited cerebral I/R-induced apoptosis and ameliorated the Bax/Bcl-2 ratio and cleaved-caspase 3 level. Collectively, our findings reveal that ICS II significantly ameliorates I/R-induced BBB disruption and neuronal apoptosis in MCAO rats by regulating the MMP9/TIMP1 balance and inhibiting the caspase 3-dependent apoptosis pathway.

Effect of 2″-O-Rhamnosyl Icariside II, Baohuoside I and Baohuoside II in Herba Epimedii on Cytotoxicity Indices in HL-7702 and HepG2 Cells.

Herba Epimedii, a commonly used Chinese medicine, has attracted much attention recently because of its potential hepatotoxic effects. 2″-O-Rhamnosyl icariside II, baohuoside I and baohuoside II are the main components of Herba Epimedii, and previous research indicates that these three compounds are related to the hepatotoxicity of Herba Epimedii. To test this idea, in this study, HL-7702 and HepG2 cells were chosen as the in vitro models and the influences of these three compounds on a series of cytotoxicity indices, including ALT, AST, LDH, SOD, GSH, MDA, ROS and MMP, were determined. The results showed that at certain concentrations, the three compounds had different effects on the indices. Among them, baohuoside I at high concentration (32 µg/mL) displayed more significant cytotoxicity than the other two compounds; therefore, it was inferred to be more closely correlated with the liver injury induced by Herba Epimedii combined with the previous study, and its toxic mechanisms may be involved in increasing oxidative stress and inducing apoptosis. The findings of this study may provide evidence of the toxic composition of Herba Epimedii to preliminarily discuss the toxic mechanisms and provide improved guidance for its clinical safety.

Icariside II, a Phosphodiesterase-5 Inhibitor, Attenuates Beta-Amyloid-Induced Cognitive Deficits via BDNF/TrkB/CREB Signaling.

BACKGROUND/AIMS: Icariside II (ICS II) is an active component from Epimedium brevicornum, a Chinese medicine extensively used in China. Our previous study has proved that ICS II protects against learning and memory impairments and neuronal apoptosis in the hippocampus induced by beta-amyloid25-35 (Aß25-35) in rats. However, its in-depth underlying mechanisms remain still unclear. Hence this study was designed to explore the potential underlying mechanisms of ICS II by experiments with an in vivo model of Aß25-35-induced cognitive deficits in rats combined with a neuronal-like PC12 cells injury in vitro model. METHODS: The cognitive deficits was measured using Morris water maze test, and apoptosis, intracellular reactive oxygen species (ROS) and mitochondrial ROS levels were detected by TUNEL, DCFH-DA and Mito-SOX staining, respectively. Expression of Bcl-2, Bax, brain derived neurotrophic factor (BDNF), tyrosine receptor kinase B (TrkB), and cAMP response element binding (p-CREB) and active-Caspase 3 levels were evaluated by Western blot. RESULTS: It was found that ICS II, a phosphodiesterase-5 inhibitor, significantly attenuated cognitive deficits caused by Aß25-35 injection in rats, and ICS II not only significantly enhanced the expression of BDNF and TrkB, but also activated CREB. Furthermore, ICS II also significantly abrogated Aß25-35-induced PC12 cell injury, and inhibited Aß25-35-induced intracellular reactive oxygen species (ROS) overproduction, as well as mitochondrial ROS levels. In addition, ICS II up-regulated the expressions of BDNF and TrkB consistent with the findings in vivo. ANA-12, a TrkB inhibitor, blocked the neuroprotective effect of ICS II on Aß25-35-induced neuronal injury. CONCLUSION: ICS II mitigates Aß25-35-induced cognitive deficits and neuronal cell injury by upregulating the BDNF/TrkB/CREB signaling, suggesting that ICS II can be used as a potential therapeutic agent for dementia, such as Alzheimer's disease.

Study of the osteogenesis effect of icariside II and icaritin on canine bone marrow mesenchymal stem cells.

This study aimed to identify the osteogenesis effect of icariside II (ICSII) and icaritin (ICT) in vitro. Bone marrow mesenchymal stem cells (BMSCs) were treated with ICSII and ICT in order to detect the proliferation and differentiation of BMSCs, the expression of the osteogenesis-related proteins with or without osteogenic medium (OM) and genes, Runt-related transcription factor 2 (Runx-2), osteocalcin (OCN), osteopontin (OPN), osterix, and basic fibroblast growth factor (bFGF), and the phosphorylation levels of mitogen-activated protein kinase (MAPK). We found that the optical density increased and alkaline phosphatase decreased after the BMSCs were treated with different concentrations of ICSII; however, ICT showed an opposing effect. The formation of calcium nodules was observed after the BMSCs were treated with ICSII and ICT. The expression level of osteogenesis-related proteins was enhanced following treatment with both ICSII or ICT, while the expression level of the osteogenesis-related genes Runx-2, OCN, OPN, osterix, and bFGF significantly increased with ICSII treatment (P < 0.05), and only Runx-2 and bFGF significantly increased (P < 0.01) with ICT. The expression of osteogenic differentiation-related proteins (except OPN) following treatment with ICSII + OM or ICT + OM was not notably increased. Both ICSII and ICT elevated the phosphorylation levels of MAPK/ERK, which was attenuated by GDC-0994 (an inhibitor of MAPK/ERK). Collectively, these data indicate that ICSII and ICT facilitate orientation osteogenic differentiation of BMSCs, which is most likely via the MAPK/ERK pathway. OM did not synergistically enhance the osteogenesis effect of ICSII and ICT.

Icariside II attenuates cardiac remodeling via AMPKα2/mTORC1 in vivo and in vitro.

Icariside II (ICA II), a flavonoid derived from Epimediumbrevicormum Maxin in, has multiple biological activities in Chinese traditional medicine. Our study aimed to investigate the potential activity of ICA II against cardiac remodeling and the underlying mechanism. Mice received aorta banding (AB) or sham surgery, and then were randomly divided into ICA II or vehicle (veh) group for 6 weeks. After echocardiography and pressure-volume loop examination, hearts were harvested for histopathological analysis and molecular mechanism investigation. Additionally, neonatal rat cardiomyocytes (NRCM) were used for in vitro experiments. ICA II attenuated the systolic and diastolic cardiac dysfunction, and protected mouse heart from hypertrophy and fibrosis. The underlying mechanism might involve in the regulation of Akt, AMPKα and mTORC. In in vitro experiment, ICA II prevented phenylephrine (PE) induced NRCM hypertrophy by regulating AMPKα/mTORC pathway. This protective effect was disappeared after treatment with Compound C (CpC), an AMPKα inhibitor. Moreover, ICA II activated AMPK at baseline. ICAII was superior to resveratrol in activating AMPKα and similar to AICAR. ICA II protected against cardiac remodeling and NRCM hypertrophy by regulating AMPK/mTORC pathway. ICA II may be a candidate for the treatment of malignant cardiac remodeling.

Synthesis and Biological Evaluation of Novel Alkyl Amine Substituted Icariside II Derivatives as Potential Anticancer Agents.

A series of novel alkyl amine-substituted icariside II (ICA II) derivatives were synthesized by Mannich reactions at the 6-C position (compounds 4a⁻d) and changing the carbon chain length at the 7-OH position (compounds 7a⁻h), and their in vitro antitumor activity towards human breast cancer lines (MCF-7 and MDA-MB-231) and human hepatoma cell lines (HepG2 and HCCLM3-LUC) were evaluated by the MTT assay. Compared with ICA II, most of the twelve derivatives showed good micromole level activity and a preliminary structure-activity relationship (SAR) for the anticancer activity was obtained. Compound 7g showed the most potent inhibitory activity for the four cancer cell lines (13.28 µM for HCCLM3-LUC, 3.96 µM for HepG2, 2.44 µM for MCF-7 and 4.21 µM for MDA-MB-231), which was 2.94, 5.54, 12.56 and 7.72-fold stronger than that of ICA II. The preliminary SAR showed that the introduction of a alkyl amine substituent at 6-C was not favorable for the anticancer activity, while most of the 7-O-alkylamino derivatives exhibited good antitumor activity and the anticancer activity 7-O-alkylamino derivatives were influenced by the alkyl chain length and the different terminal amine substituents. Furthermore, the effects of compound 7g on apoptosis and cell cycle of MCF-7 cells were further investigated, which showed that compound 7g triggered apoptosis and arrested the cell cycle at the G0/G1 phase in MCF-7 cells. Our findings indicate that compound 7g may be a promising anticancer drug candidate lead.

Icariside II, a novel phosphodiesterase 5 inhibitor, protects against H2 O2 -induced PC12 cells death by inhibiting mitochondria-mediated autophagy.

Oxidative stress is a major cause of cellular injury in a variety of human diseases including neurodegenerative disorders. Thus, removal of excessive reactive oxygen species (ROS) or suppression of ROS generation may be effective in preventing oxidative stress-induced cell death. This study was designed to investigate the effect of icariside II (ICS II), a novel phosphodiesterase 5 inhibitor, on hydrogen peroxide (H2 O2 )-induced death of highly differentiated rat neuronal PC12 cells, and to further examine the underlying mechanisms. We found that ICS II pre-treatment significantly abrogated H2 O2 -induced PC12 cell death as demonstrated by the increase of the number of metabolically active cells and decrease of intracellular lactate dehydrogenase (LDH) release. Furthermore, ICS II inhibited H2 O2 -induced cell death through attenuating intracellular ROS production, mitochondrial impairment, and activating glycogen synthase kinase-3ß (GSK-3ß) as demonstrated by reduced intracellular and mitochondrial ROS levels, restored mitochondrial membrane potential (MMP), decreased p-tyr216-GSK-3ß level and increased p-ser9-GSK-3ß level respectively. The GSK-3ß inhibitor SB216763 abrogated H2 O2 -induced cell death. Moreover, ICS II significantly inhibited H2 O2 -induced autophagy by the reducing autophagosomes number and the LC3-II/LC3-I ratio, down-regulating Beclin-1 expression, and up-regulating p62/SQSTM1 and HSP60 expression. The autophagy inhibitor 3-methyl adenine (3-MA) blocked H2 O2 -induced cell death. Altogether, this study demonstrated that ICS II may alleviate oxidative stress-induced autophagy in PC12 cells, and the underlying mechanisms are related to its antioxidant activity functioning via ROS/GSK-3ß/mitochondrial signalling pathways.

Icariside II inhibits the EMT of NSCLC cells in inflammatory microenvironment via down-regulation of Akt/NF-κB signaling pathway.

Inflammatory microenvironment created by immune cells is favorable for tumor metastasis. Epithelial-mesenchymal transition (EMT) is involved in the progression of cancer invasion and metastasis in inflammatory microenvironment. In this study, we sought to investigate the effects of Icariside II, a flavonol glycoside isolated from Epimedium koreanum Nakai, on A549 and H1299 cells migration in inflammatory microenvironment. At non-cytotoxic concentrations, Icariside II could inhibit invasion and EMT of A549 and H1299 cells induced by LPS-stimulated-THP-1 medium or by pro-inflammatory cytokine tumor necrosis factor-α (TNF-α). Exposure to Icariside II resulted in the increment of E-cadherin, accompanied with decrement of N-cadherin, vimentin, Slug, and Snail in A549 and H1299 cells stimulated by TNF1α. Furthermore, Icariside II suppressed TNF-α-triggered nuclear translocation of NF-κB and phosphorylation of IκBα, and repressed the DNA-binding activity of NF-κB. Further data demonstrated that Akt/GSK-3ß, other than MAPK signaling pathway was taking a part in the inhibitory potential of Icariside II on NF-κB activation. Importantly, Icariside II also impeded lung metastasis of A549 cells and EMT in nude mice. In conclusion, Icariside II might prohibit invasion through inactivating Akt/NF-κB pathway. © 2016 Wiley Periodicals, Inc.

Icariin Metabolism by Human Intestinal Microflora.

Icariin is a major bioactive compound of Epimedii Herba, a traditional oriental medicine exhibiting anti-cancer, anti-inflammatory and anti-osteoporosis activities. Recently, the estrogenic activities of icariin drew significant attention, but the published scientific data seemed not to be so consistent. To provide fundamental information for the study of the icaritin metabolism, the biotransformation of icariin by the human intestinal bacteria is reported for the first time. Together with human intestinal microflora, the three bacteria Streptococcus sp. MRG-ICA-B, Enterococcus sp. MRG-ICA-E, and Blautia sp. MRG-PMF-1 isolated from human intestine were reacted with icariin under anaerobic conditions. The metabolites including icariside II, icaritin, and desmethylicaritin, but not icariside I, were produced. The MRG-ICA-B and E strains hydrolyzed only the glucose moiety of icariin, and icariside II was the only metabolite. However, the MRG-PMF-1 strain metabolized icariin further to desmethylicaritin via icariside II and icaritin. From the results, along with the icariin metabolism by human microflora, it was evident that most icariin is quickly transformed to icariside II before absorption in the human intestine. We propose the pharmacokinetics of icariin should focus on metabolites such as icariside II, icaritin and desmethylicaritin to explain the discrepancy between the in vitro bioassay and pharmacological effects.