Icariin enhances endothelial nitric-oxide synthase expression on human endothelial cells in vitro

Pharmacology-Based Prediction of the Targets and Mechanisms for Icariin against Myocardial Infarction

Background and Objectives: This study aims to illustrate the mechanisms underlying the therapeutic effect of Icariin after myocardial infarction (MI). Materials and Methods: Based on the network pharmacology strategy, we predict the therapeutic targets of Icariin against MI and investigate the pharmacological molecular mechanisms. A topological network was created. Biological process and Kyoto Encyclopedia of Genes and Genomes pathway enrichment were also performed. We also conducted the molecular docking analysis to stimulate the component–target interaction further and validate the direct bind effect. Results: Network pharmacology analysis identified 61 candidate genes related to the therapeutic effect of Icariin against MI. EGFR, AKT1, TP53, JUN, ESR1, PTGS2, TNF, RELA, HSP90AA1, and BCL2L1 were identified as hub genes. The biological processes of the candidate targets were significantly involved in the reactive oxygen species metabolic process, response to hypoxia, response to decreased oxygen levels, response to oxidative stress, regulation of reactive oxygen species metabolic process, and so forth. Overall, biological process enrichment analysis indicated that the protective effect of Icariin against MI might be associated with oxidative stress. Moreover, the pathway analysis showed that the candidate targets were closely associated with lipid and atherosclerosis, AGE-RAGE signaling pathway in diabetic complications, HIF-1 signaling pathway, etc. We identified the conformation with the lowest affinity score as the docking conformation. The simulated molecular docking was displayed to illustrate the topical details of the binding sites between Icariin and TNF protein. Conclusions: This study provides an overview of the mechanisms underlying the protective effect of Icariin against MI.

Angiogenic and Osteogenic Effects of Flavonoids in Bone Regeneration

Bone is a highly vascularised tissue that relies on a close spatial and temporal interaction between blood vessels and bone cells. As a result, angiogenesis is critical for bone formation and healing. The vascular system supports bone regeneration by delivering oxygen, nutrients, and growth factors, as well as facilitating efficient cell-cell contact. Most clinical applications of engineered bone grafts are hampered by insufficient vascularization after implantation. Over the last decade, a number of flavonoids have been reported to have osteogenic-angiogenic potential in bone regeneration because of their excellent bioactivity, low cost, availability, and minimal in vivo toxicity. During new bone formation, the osteoinductive nature of certain flavonoids is involved in regulating multiple signaling pathways contributing toward the osteogenic-angiogenic coupling. This review briefly outlines the osteogenic-angiogenic potential of those flavonoids and the mechanisms of their action in promoting bone regeneration. However, further studies are needed to investigate their delivery strategies and establish their clinical efficacy. This article is protected by copyright. All rights reserved.

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.

Harnessing polyphenol power by targeting eNOS for vascular diseases

Vascular diseases arise due to vascular endothelium dysfunction in response to several pro-inflammatory stimuli and invading pathogens. Thickening of the vessel wall, formation of atherosclerotic plaques consisting of proliferating smooth muscle cells, macrophages and lymphocytes are the major consequences of impaired endothelium resulting in atherosclerosis, hypercholesterolemia, hypertension, type 2 diabetes mellitus, chronic renal failure and many others. Decreased nitric oxide (NO) bioavailability was found to be associated with anomalous endothelial function because of either its reduced production level by endothelial NO synthase (eNOS) which synthesize this potent endogenous vasodilator from L-arginine or its enhanced breakdown due to severe oxidative stress and eNOS uncoupling. Polyphenols are a group of bioactive compounds having more than 7000 chemical entities present in different cereals, fruits and vegetables. These natural compounds possess many OH groups which are largely responsible for their strong antioxidative, anti-inflammatory antithrombotic and anti-hypersensitive properties. Several flavonoid-derived polyphenols like flavones, isoflavones, flavanones, flavonols and anthocyanidins and non-flavonoid polyphenols like tannins, curcumins and resveratrol have attracted scientific interest for their beneficial effects in preventing endothelial dysfunction. This article will focus on in vitro as well as in vivo and clinical studies evidences of the polyphenols with eNOS modulating activity against vascular disease condition while their molecular mechanism will also be discussed.

Secondary Metabolites of Plants as Modulators of Endothelium Functions

According to the World Health Organization, cardiovascular diseases are the main cause of death worldwide. They may be caused by various factors or combinations of factors. Frequently, endothelial dysfunction is involved in either development of the disorder or results from it. On the other hand, the endothelium may be disordered for other reasons, e.g., due to infection, such as COVID-19. The understanding of the role and significance of the endothelium in the body has changed significantly over time—from a simple physical barrier to a complex system encompassing local and systemic regulation of numerous processes in the body. Endothelium disorders may arise from impairment of one or more signaling pathways affecting dilator or constrictor activity, including nitric oxide–cyclic guanosine monophosphate activation, prostacyclin–cyclic adenosine monophosphate activation, phosphodiesterase inhibition, and potassium channel activation or intracellular calcium level inhibition. In this review, plants are summarized as sources of biologically active substances affecting the endothelium. This paper compares individual substances and mechanisms that are known to affect the endothelium, and which subsequently may cause the development of cardiovascular disorders.

Bioactive Herbal Extracts of Traditional Chinese Medicine Applied with the Biomaterials: For the Current Applications and Advances in the Musculoskeletal System

Traditional Chinese medicine (TCM) has demonstrated superior therapeutic effect for musculoskeletal diseases for thousands of years. Recently, the herbal extracts of TCM have received rapid advances in musculoskeletal tissue engineering (MTE). A literature review collecting both English and Chinese references on bioactive herbal extracts of TCM in biomaterial-based approaches was performed. This review provides an up-to-date overview of application of TCMs in the field of MTE, involving regulation of multiple signaling pathways in osteogenesis, angiogenesis, anti-inflammation, and chondrogenesis. Meanwhile, we highlight the potential advantages of TCM, opening the possibility of its extensive application in MTE. Overall, the superiority of traditional Chinese medicine turns it into an attractive candidate for coupling with advanced additive manufacturing technology.

UPLC-MS-QTOF analysis and antifungal activity of Cumaru (Amburana cearensis)

This study was aimed at investigating the phytochemical constituents, antifungal properties and antibiotic-modifying activity of the aqueous crude extract and fractions of Amburana cearensis seeds (CEFAC). The CEFAC were chemically characterized by LC-MS/MS-QTOF. In addition, the antifungal activity was assayed by the microdilution method against strains of Candida albicans. The phytochemical profile of CEFAC exhibited phenolic compounds, organic acids, and polyphenols. The results of the assessment of antifungal activity reveled an IC₅₀ ranging from 45.6 to 2048 µg/mL. Interestingly, when CEFAC was associated with Fluconazole, we evidenced a decreased IC₅₀ (1.81-11.9 µg/mL), suggesting a synergism with antibiotic. It was possible to identify in the crude extract and fractions several phenolic compounds, organic acids, and some polyphenols in positive ionization mode. These results suggest that CEFAC may present compounds with the ability to interact and act synergistically with antimicrobial drugs, highlighting its potential as an alternative source for the development of new antimicrobial agents.

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

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

Pharmacological effects of icariin

Icariin (ICA) is a principal active component from traditional Chinese medicine Epimedium grandiflorum. To explain its traditional medical usages by modern science, a variety of pharmacological effects have been studied for ICA. In this review, we summarized the pharmacokinetics of ICA as well as its pharmacological mechanisms in neurodegenerative disease, cardiovascular disease, anti-osteoporosis, anti-inflammation, anti-oxidative stress, anti-depression and anti-tumors.

Icariin reduces high glucose-induced endothelial progenitor cell dysfunction via inhibiting the p38/CREB pathway and activating the Akt/eNOS/NO pathway

High glucose (HG) impairs endothelial progenitor cell (EPC) function. The activation of p38 mitogen-activated protein kinase and the inhibition of the Akt/eNOS/NO pathway serve central roles in this process. Icariin has protective effects in endothelial cells. The aim of the present study was to investigate the effects of icariin on HG-induced EPC dysfunction, including proliferation, migration and tube formation. Experiments were performed with EPCs isolated from the femurs and tibias of Sprague-Dawley rats in vitro. In a dose-dependent manner, icariin reversed the inhibition of EPC proliferation induced by HG treatment, and the maximal effective concentration of icariin was 1 µM [Fold change (FC):0.90±0.07, P=0.0124 vs. HG group]. The impaired EPC migration and tube formation induced by glucose was partially restored by 1 µM icariin treatment (FC: 0.81±0.08, P=0.0148 vs. HG group for migration; 0.82±0.03, P=0.0214 vs. HG group for tube formation). Furthermore, icariin significantly suppressed HG-induced p38 and cAMP response element binding protein (CREB) phosphorylation in EPCs (FC: 1.84±0.21, P=0.0238 vs. HG group for p38; FC: 2.24±0.15, P=0.0068 vs. HG group for CREB). Increased Akt and endothelial nitric oxide (NO) synthase (eNOS) activation was also observed after icariin treatment (FC: 0.64±0.08, P=0.0047 vs. HG group for Akt; FC:0.53±0.05, P=0.0019 vs. HG group for eNOS), which was followed by increased NO production (FC: 0.69±0.06, P=0.0064 vs. HG group). In conclusion, icariin attenuated HG-induced EPC dysfunction, which may be partially attributed to the inhibition of the p38/CREB pathway and the activation of the Akt/eNOS/NO pathway. Icariin may be a therapeutic candidate for improving the function of EPC.

Retracted: Icariin attenuates methotrexate chemotherapy-induced bone marrow microvascular damage and bone loss in rats

Methotrexate (MTX), a widely used antimetabolite in paediatric cancer to treatment, has been widely reported to cause bone loss and bone marrow (BM) microvascular (particularly sinusoids) damage. Investigations must now investigate how MTX-induced bone loss and microvasculature damage can be attenuated/prevented. In the present study, we examined the potency of icariin, an herbal flavonoid, in reducing bone loss and the dilation/damage of BM sinusoids in rats caused by MTX treatment. Groups of young rats were treated with five daily MTX injections (0.75 mg/kg) with and without icariin oral supplementation until Day 9 after the first MTX injection. Histological analyses showed a significant reduction in the bone volume/tissue volume (BV/TV) fraction (%) and trabecular number in the metaphysis trabecular bone of MTX-treated rats, but no significant changes in trabecular thickness and trabecular spacing. However, the BV/TV (%) and trabecular number were found to be significantly higher in MTX + icariin-treated rats than those of MTX alone-treated rats. Gene expression analyses showed that icariin treatment maintained expression of osteogenesis-related genes but suppressed the induction of adipogenesis-related genes in bones of MTX-treated rats. In addition, icariin treatment attenuated MTX-induced dilation of BM sinusoids and upregulated expression of endothelial cell marker CD31 in the metaphysis bone of icariin + MTX-treated rats. Furthermore, in vitro studies suggest that icariin treatment can potentially enhance the survival of cultured rat sinusoidal endothelial cells against cytotoxic effect of MTX and promote their migration and tube formation abilities, which is associated with enhanced production of nitric oxide.

Crosstalk between chitosan and cell signaling pathways

The field of tissue engineering (TE) experiences its most exciting time in the current decade. Recent progresses in TE have made it able to translate into clinical applications. To regenerate damaged tissues, TE uses biomaterial scaffolds to prepare a suitable backbone for tissue regeneration. It is well proven that the cell-biomaterial crosstalk impacts tremendously on cell biological activities such as differentiation, proliferation, migration, and others. Clarification of exact biological effects and mechanisms of a certain material on various cell types promises to have a profound impact on clinical applications of TE. Chitosan (CS) is one of the most commonly used biomaterials with many promising characteristics such as biocompatibility, antibacterial activity, biodegradability, and others. In this review, we discuss crosstalk between CS and various cell types to provide a roadmap for more effective applications of this polymer for future uses in tissue engineering and regenerative medicine.

Mechanism of Action of Icariin in Bone Marrow Mesenchymal Stem Cells

Osteoporosis, femoral head necrosis, and congenital bone defects are orthopedic disorders characterized by reduced bone generation and insufficient bone mass. Bone regenerative therapy primarily relies on the bone marrow mesenchymal stem cells (BMSCs) and their ability to differentiate osteogenically. Icariin (ICA) is the active ingredient of Herba epimedii, a common herb used in traditional Chinese medicine (TCM) formulations, and can effectively enhance BMSC proliferation and osteogenesis. However, the underlying mechanism of ICA action in BMSCs is not completely clear. In this review, we provide an overview of the studies on the role and mechanism of action of ICA in BMSCs, to provide greater insights into its potential clinical use in bone regeneration.

Icariin prevents cytokine-induced β-cell death by inhibiting NF-κB signaling

The loss of insulin secretion in type I diabetes mellitus (T1DM) is caused by autoimmune-mediated destruction of insulin-producing pancreatic β-cells. Inflammatory cytokines and immune cell infiltration activate oxidative and endoplasmic reticulum (ER) stress, resulting in reduced β-cell viability. The current pharmacological agents used to control blood glucose have a limited effective duration and are accompanied by strong side effects. Blocking the inflammatory and immune responses that cause the β-cell damage has been investigated as a novel therapeutic approach to control T1DM. Icariin is a flavonoid component of Chinese medicinal herbs that has anti-inflammatory effects in vitro and in vivo. The results of the present study revealed that icariin abrogates the pro-apoptotic effect of inflammatory cytokines and significantly suppresses the activation of nuclear factor (NF)-κB in rat pancreatic β-cell lines. The present study may provide a basis for the potential use of icariin as a therapeutic agent for T1DM.

The potential of herb medicines in the treatment of esophageal cancer

Esophageal cancer (EC) is one of common malignant neoplasms in the world. Due to dietary habits, environmental factors, stress and so on, larger numbers of person are diagnose with EC every year. Currently, the clinical treatment of EC mainly includes radiotherapy, chemotherapy, surgical resection alone or combined strategy. These treatment options are insufficient and often associated with a number of side effects. Medicinal herbs containing Traditional Chinese Medicine (TCM) have been used as an adjunct treatment for alleviating the side effects of chemotherapy or radiotherapy and for improving the quality of life of cancer patients. The monomer compounds obtained from medicinal herbs also exhibit potential anti-cancer activity against various type cancer cell lines including esophageal cancer, and have the ability to enhance cancer cells sensitizing to chemotherapy or radiotherapy. In this review, we summarize some monomers and composite of medicinal herbs with anti-cancer activity for EC, and elaborate their mechanism of action. Understanding the exact mechanism of their actions may provide valuable information for their possible application in cancer therapy and prevention. This is beneficial for the use and development of medicinal herbs for diseases therapy in the future.

Antioxidant capacity of Typha angustifolia extracts and two active flavonoids

CONTEXT

The pollen of Typha angustifolia L. (Typhaceae) has been used as a traditional Chinese medicine for improving the microcirculation and promoting wound healing. Flavonoids are the main constituent in the plant, but little is known about the antioxidant activity of the principal constituent of the pollen in detail.

OBJECTIVES

To assess the antioxidant activities of ethanol and water extracts and two constituents of the pollen.

MATERIALS AND METHODS

Plant material (1 g) was extracted by 95% ethanol and water (10 mL × 2, 1 h each), respectively. The extracted activities (0.8-2.6 mg/mL) were measured by DPPH and the reducing activity of ferric chloride (1.7-2.6 mg/mL). Typhaneoside and isorhamnetin-3-O-neohesperidoside (I3ON) (2.8-70 μmol/L) were investigated on the relationship between NO, MDA and SOD in HUVECs treated with 100 μg/mL of LPS for 24 h.

RESULTS

Nine compounds were identified by UPLC-MS. Ethanol extract showed IC₅₀ values in DPPH (39.51 ± 0.72) and Fe³⁺ reducing activity (82.76 ± 13.38), higher than the water extract (50.85 ± 0.74) and (106.33 ± 6.35), respectively. Typhaneoside and I3ON promoted cell proliferation at the respective concentration range of 2.8 to 70 μmol/L (p < 0.01). This two compounds decreased MDA (1.91 ± 0.10, 1.80 ± 0.34, p < 0.05) and NO levels (14.64 ± 0.08, 13.10 ± 0.88, p < 0.01), respectively, and increased SOD level (22.94 ± 2.48, 23.57 ± 2.38, p < 0.01) at the concentration of 70 μmol/L compared with LPS group.

CONCLUSIONS

The constituents from Typha angustifolia could be a novel therapeutic strategy for LPS-induced inflammation.

Icariin, an Anti-atherosclerotic Drug from Chinese Medicinal Herb Horny Goat Weed

Icariin is a major bioactive pharmaceutical constituent isolated from Chinese medicine Horny Goat Weed (Ying Yang Huo) with potent cardiovascular protective functions. Emerging evidence in the past decade has shown that Icariin possesses multiple atheroprotective functions, through multiple mechanisms, including attenuating DNA damage, correcting endothelial dysfunction, inhibiting the proliferation and migration of smooth muscle cells, repressing macrophage-derived foam cell formation and inflammatory responses, as well as preventing platelet activation. All of these protective effects, combined with its lipid-modulatory effects, contribute to the broad atheroprotective effects of Icariin. In this review, we will summarize the anti-atherosclerotic properties of Icariin and highlight future perspectives in developing Icariin as a promising anti-atherosclerotic drug.

Icariin exerts inhibitory effects on the growth and metastasis of KYSE70 human esophageal carcinoma cells via PI3K/AKT and STAT3 pathways

Esophageal cancer is one of the leading causes of cancer related mortality across the globe. The current treatment options are insufficient and are associated with number of side effects. Therefore there is a pressing need to develop effective and more efficient strategies for the treatment of esophageal cancer. Consistently, natural products are considered potential candidates for develop of cancer chemotherapy. Icariin is a naturally occurring flavonol glucoside and has been reported to possess tremendous pharmacological potential ranging from neuroprotection to anticancer activity. However, the pharmacological role of icariin in esophageal cancer is still largely unclear. Here in the present study, icariin was evaluated for its anticancer activity against KYSE70 esophageal cancer cells and the possible underlying mechanism was determined. Icariin induced cytotoxicity with an IC₅₀ of 40μM in esophageal cancer cells. These inhibitory effects were due to apoptosis through reactive oxygen species (ROS) mediated alterations in mitochondrial membrane potential (MMP). The results indicated that icariin enhanced the accretion of ROS upto 260% and reduced the MMP upto 48% at 100μM. Icariin also induced G2/M cell cycle arrest as evident from the significant increase in the G2 cell populations of KYSE70 esophageal cancer cells. Additionally, icariin inhibited esophageal cancer cell migration, invasion and metastasis by regulating the expression of epithelial to mesenchymal transition (EMT) markers. Results also indicated that icariin reduced cell viability and migration in part through suppression of the PI3K/AKT and STAT3 pathways. Taken together, our results indicate that icariin may prove a potential natural anticancer molecule against esophageal cancer.

Slowly Delivered Icariin/Allogeneic Bone Marrow-Derived Mesenchymal Stem Cells to Promote the Healing of Calvarial Critical-Size Bone Defects

Bone tissue engineering technique is a promising strategy to repair large-volume bone defects. In this study, we developed a 3-dimensional construct by combining icariin (a small-molecule Chinese medicine), allogeneic bone marrow-derived mesenchymal stem cells (BMSCs), and a siliceous mesostructured cellular foams-poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (SMC-PHBHHx) composite scaffold. We hypothesized that the slowly released icariin could significantly promote the efficacy of SMC-PHBHHx/allogeneic BMSCs for repairing critical-size bone defects in rats. In in vitro cellular experiments, icariin at optimal concentration (10^-6 mol/L) could significantly upregulate the osteogenesis- and angiogenesis-related genes and proteins, such as Runx2, ALP, osteocalcin, vascular endothelial growth factors, and fibroblast growth factors, as well as the mineralization of BMSCs. Icariin that was adsorbed onto the SMC-PHBHHx scaffold showed a slow release profile within a 2-week monitoring span. Eight weeks after implantation in calvarial critical-size bone defects, the constructs with icariin were associated with significantly higher bone volume density, trabecular thickness, trabecular number, and significantly lower trabecular separation than the constructs without icariin. Histomorphometric analysis showed that icariin was also associated with a significantly higher density of newly formed blood vessels. These data suggested a promising application potential of the icariin/SMC-PHBHHx/allogeneic BMSCs constructs for repairing large-volume bone defects in clinic.

Icariin displays anticancer activity against human esophageal cancer cells via regulating endoplasmic reticulum stress-mediated apoptotic signaling

In this study, we investigated the antitumor activity of icariin (ICA) in human esophageal squamous cell carcinoma (ESCC) in vitro and in vivo and explored the role of endoplasmic reticulum stress (ERS) signaling in this activity. ICA treatment resulted in a dose- and time-dependent decrease in the viability of human EC109 and TE1 ESCCs. Additionally, ICA exhibited strong antitumor activity, as evidenced by reductions in cell migration, adhesion, and intracellular glutathione (GSH) levels and by increases in the EC109 and TE1 cell apoptotic index, Caspase 9 activity, reactive oxygen species (ROS) level, and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity. Furthermore, ICA treatments upregulated the levels of ERS-related molecules (p-PERK, GRP78, ATF4, p-eIF2α, and CHOP) and a pro-apoptotic protein (PUMA) and simultaneously downregulated an anti-apoptotic protein (Bcl2) in the two ESCC cell lines. The downregulation of ERS signaling using eIF2α siRNA desensitized EC109 and TE1 cells to ICA treatment, and the upregulation of ERS signaling using thapsigargin sensitized EC109 and TE1 cells to ICA treatment. In summary, ERS activation may represent a mechanism of action for the anticancer activity of ICA in ESCCs, and the activation of ERS signaling may represent a novel therapeutic intervention for human esophageal cancer.

Activation of endoplasmic reticulum stress is involved in the activity of icariin against human lung adenocarcinoma cells

In this study, we investigated the anticancer activity of icariin (ICA) against human lung adenocarcinoma cells in vitro and in vivo and explored the role of endoplasmic reticulum (ER) stress (ERS) signaling in this process. ICA treatment resulted in a dose- and time-dependent decrease in the viability of human lung adenocarcinoma A549 cells. Additionally, ICA exhibited potent anticancer activity, as evidenced by reductions in A549 cell adhesion, migration and intracellular glutathione (GSH) levels and increases in the apoptotic index, Caspase 3 activity, and reactive oxygen species. Furthermore, ICA treatment increased the expression of ERS-related molecules (p-PERK, ATF6, GRP78, p-eIF2α, and CHOP), up-regulated the apoptosis-related protein PUMA and down-regulated the anti-apoptosis-related protein Bcl2. The down-regulation of ERS signaling using PERK siRNA desensitized lung adenocarcinoma cells to ICA treatment, whereas the up-regulation of ERS signaling using thapsigargin (THA) sensitized lung adenocarcinoma cells to ICA treatment. Additionally, ICA inhibited the growth of human lung adenocarcinoma A549 cell xenografts by increasing the expression of ERS-related molecules (p-PERK and CHOP), up-regulating PUMA, and down-regulating Bcl2. These data indicate that ICA is a potential inhibitor of lung adenocarcinoma cell growth by targeting ERS signaling and suggest that the activation of ERS signaling may represent a novel therapeutic intervention for lung adenocarcinoma.

Anti-proliferative and cytoskeleton-disruptive effects of icariin on HepG2 cells

Several biological properties of icariin have been identified, including its anticancer effect. However, the potential mechanisms underlying the effect of icariin on HepG2 hepatocellular carcinoma cells remain to be elucidated. The aim of the present study was to examine the effects of icariin on the proliferation and cytoskeleton of HepG2 cells. A 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5 diphenyltetrazolium bromide assay was used to assess the antiproliferative effects of icariin and to determine the optimal concentration and treatment schedule of icariin on the HepG2 cells. Cell cycle analysis was performed using fluorescence activated cell sorting, the protein expression of B‑cell lymphoma (Bcl)‑2 was determined using immunohistochemical and western blot analyses, and F‑actin in the cells was examined using confocal microscopy. The chemotherapeutic drug, oxaliplatin, was used as a positive control. The results demonstrated that the optimal concentration of icarrin to produce an antiproliferative effect on HepG2 cells was 10‑5 mol/l, and the optimal treatment duration was 72 h. The icariin group had a significantly higher proportion of cells in the G0/G1 phase, compared with the control group, treated with high glucose Dulbecco's modified Eagles medium with 10% fetal bovine serum (P<0.05). The proportion of HepG2 cells in the S phase was significantly lower in the oxaliplatin (24.19%; P<0.05) and icariin (21.07%; P<0.01) groups, compared with the control group (28.62%). Icariin markedly decreased the expression of Bcl‑2, compared with the control (P<0.01), and disrupted the polymerization of F‑actin filaments in the HepG2 cells. Therefore, the present study demonstrated that, at an optimum concentration of 10‑5 mol/l, icariin inhibited the proliferation of the HepG2 cells, promoted apoptosis by decreasing the expression of Bcl‑2, and disrupted the actin cytoskeleton.

Icariin: A promising osteoinductive compound for repairing bone defect and osteonecrosis

Icariin (Ica), the main active component of Herba Epimedii, has been identified as an osteogenic and angiogenic phytomolecule. To develop a bioactive scaffold for enhancing bone repair, Ica was loaded into porous tricalcium phosphate (TCP) scaffolds, and the obtained porous Ica/TCP composites were investigated for treating osteonecrosis of the femoral head (ONFH) in a rabbit model. ONFH was histopathologically confirmed at two weeks after methylprednisolone acetate injection, and the rabbits were treated with porous Ica/TCP scaffolds (group A), porous TCP scaffolds (group B), and autogenous cancellous bone graft (group C). At 12 weeks, the amount of newly formed bone in group A increased significantly compared with that in group B (P = 0.003). The mean histological and radiological scores for repaired defects in group A were significantly higher than those in group B (P = 0.007, P = 0.029, respectively), but were lower than those in group C (P = 0.032, P = 0.046, respectively). In addition, the expression of vascular endothelial growth factor by immunohistochemical testing and real-time polymerase chain reaction in group A was significantly higher than that in group B (P = 0.002, P = 0.001, respectively), but was lower than that in group C (P = 0.034, P = 0.005, respectively). Therefore, Ica can be a promising osteogenic and angiogenic compound for repairing bone defects and preventing the collapse of the femoral head in ONFH.

Icariin recovers the osteogenic differentiation and bone formation of bone marrow stromal cells from a rat model of estrogen deficiency-induced osteoporosis

A number of recent studies have suggested that icariin (ICA), a class of phytochemical with numerous biological activities, may exert protective effects against postmenopausal bone loss. However, it remains unclear whether ICA regulates or improves the osteoblastic function of bone marrow stromal cells (BMSCs) in the treatment and prevention of osteoporosis. In the present study, the osteogenic differentiation of BMSCs from ovariectomy (OVX) rats was found to be significantly decreased in vitro compared with that in rats that had undergone a sham operation. Treatment with ICA at a dose of 10-5 M was shown to restore the osteogenic differentiation of BMSCs in OVX rats. The results indicated that ICA restored the differentiation and mineralization capacity of OVX-BMSCs, which had been induced by estrogen deficiency. The effects of this compound on alkaline phosphatase (ALP) activity and calcium deposition were also measured at various time points. The number of colonies and areas that stained positive for ALP expression, and mineralized bone nodules were analyzed histochemically at 14 and 21 days after the osteogenic induction. The expression of the runt-related transcription factor 2 and osterix bone metabolism biomarker proteins and genes were detected by western blotting and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The expression of factors involved in the estrogen signaling pathway, estrogen receptor α (ERα), progesterone receptor (PR) and trefoil factor 1 (PS-2), was also detected by western blotting and RT-qPCR. ICA enhanced the expression of ERα, PR, PS-2 in OVX‑BMSCs, but this effect was abrogated when ICI 182780, an ER antagonist was added. Transplantation of BMSCs into nude mice demonstrated that ICA restored the osteogenic capability of OVX‑BMSCs in vivo. Therefore, it may be that ICA acts through the estrogen pathway in order to improve and restore the osteogenic differentiation and mineralization of OVX‑BMSCs, which are inhibited by estrogen deficiency and increasing age.

Pharmacological effects and pharmacokinetic properties of icariin, the major bioactive component in Herba Epimedii

Herba Epimedii is an important medicinal plant which has been used in various traditional Chinese formulations for thousands of years as well as in modern proprietary traditional Chinese medicine products. It has extensive clinical indications, especially for the treatment of sexual dysfunction and osteoporosis. There have been more than 260 chemical moieties identified in the genus Epimedium most of which belong to flavonoids. Icariin is the most abundant constituent in Herba Epimedii. Icariin is pharmacologically bioactive and demonstrates extensive therapeutic capacities such as osteoprotective effect, neuroprotective effect, cardiovascular protective effect, anti-cancer effect, anti-inflammation effect, immunoprotective effect and reproductive function. Particularly, the significant osteogenic effect of icariin made it a promising drug candidate in bone tissue engineering. The current review paper aims to summarize the literatures reporting the pharmacological effects of icariin. The pharmacokinetic properties of bioactive ingredients in Herba Epimedii have also been discussed.

Sinapic acid prevents hypertension and cardiovascular remodeling in pharmacological model of nitric oxide inhibited rats

Objectives

Hypertensive heart disease is a constellation of abnormalities that includes cardiac fibrosis in response to elevated blood pressure, systolic and diastolic dysfunction. The present study was undertaken to examine the effect of sinapic acid on high blood pressure and cardiovascular remodeling.

Methods

An experimental hypertensive animal model was induced by L-NAME intake on rats. Sinapic acid (SA) was orally administered at a dose of 10, 20 and 40 mg/kg body weight (b.w.). Blood pressure was measured by tail cuff plethysmography system. Cardiac and vascular function was evaluated by Langendorff isolated heart system and organ bath studies, respectively. Fibrotic remodeling of heart and aorta was assessed by histopathologic analyses. Oxidative stress was measured by biochemical assays. mRNA and protein expressions were assessed by RT-qPCR and western blot, respectively. In order to confirm the protective role of SA on endothelial cells through its antioxidant property, we have utilized the in vitro model of H₂O₂-induced oxidative stress in EA.hy926 endothelial cells.

Results

Rats with hypertension showed elevated blood pressure, declined myocardial performance associated with myocardial hypertrophy and fibrosis, diminished vascular response, nitric oxide (NO) metabolites level, elevated markers of oxidative stress (TBARS, LOOH), ACE activity, depleted antioxidant system (SOD, CAT, GPx, reduced GSH), aberrant expression of TGF-β, β-MHC, eNOS mRNAs and eNOS protein. Remarkably, SA attenuated high blood pressure, myocardial, vascular dysfunction, cardiac fibrosis, oxidative stress and ACE activity. Level of NO metabolites, antioxidant system, and altered gene expression were also repaired by SA treatment. Results of in vitro study showed that, SA protects endothelial cells from oxidative stress and enhance the production of NO in a concentration dependent manner.

Conclusions

Taken together, these results suggest that SA may have beneficial role in the treatment of hypertensive heart disease by attenuating fibrosis and oxidative stress through its antioxidant potential.

A review on plants used for improvement of sexual performance and virility

The use of plant or plant-based products to stimulate sexual desire and to enhance performance and enjoyment is almost as old as the human race itself. The present paper reviews the active, natural principles, and crude extracts of plants, which have been useful in sexual disorders, have potential for improving sexual behaviour and performance, and are helpful in spermatogenesis and reproduction. Review of refereed journals and scientific literature available in electronic databases and traditional literature available in India was extensively performed. The work reviews correlation of the evidence with traditional claims, elucidation, and evaluation of a plausible concept governing the usage of plants as aphrodisiac in total. Phytoconstituents with known structures have been classified in appropriate chemical groups and the active crude extracts have been tabulated. Data on their pharmacological activity, mechanism of action, and toxicity are reported. The present review provides an overview of the herbs and their active molecule with claims for improvement of sexual behaviour. A number of herbal drugs have been validated for their effect on sexual behavior and fertility and can therefore serve as basis for the identification of new chemical leads useful in sexual and erectile dysfunction.

Icariin, a phosphodiesterase-5 inhibitor, improves learning and memory in APP/PS1 transgenic mice by stimulation of NO/cGMP signalling

Phosphodiesterase-5 (PDE5) inhibitors are predominantly used in the treatment of erectile dysfunction, and have been recently shown to have a potential therapeutic effect for the treatment of Alzheimer's disease (AD) through stimulation of nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) signalling by elevating cGMP, which is a secondary messenger involved in processes of neuroplasticity. In the present study, the effects of a PDE5 inhibitor, icarrin (ICA), on learning and memory as well as the pathological features in APP/PS1 transgenic AD mice were investigated. Ten-month-old APP/PS1 transgenic mice overexpressing human amyloid precursor protein (APP695swe) and presenilin 1 (PS1-dE9) were given ICA (30 and 60 mg/kg) or sildenafil (SIL) (2 mg/kg), age-matched wild-type (WT) mice were given ICA (60 mg/kg), and APP/PS1 and WT control groups were given an isovolumic vehicle orally twice a day for four months. Results demonstrated that ICA treatments significantly improved learning and memory of APP/PS1 transgenic mice in Y-maze tasks. The amyloid precursor protein (APP), amyloid-beta (Aβ1-40/42) and PDE5 mRNA and/or protein levels were increased in the hippocampus and cortex of APP/PS1 mice, and ICA treatments decreased these physiopathological changes. Furthermore, ICA-treated mice showed an increased expression of three nitric oxide synthase (NOS) isoforms at both mRNA and protein levels, together with increased NO and cGMP levels in the hippocampus and cortex of mice. These findings demonstrate that ICA improves learning and memory functions in APP/PS1 transgenic mice possibly through the stimulation of NO/cGMP signalling and co-ordinated induction of NOS isoforms.

Erectile dysfunction in the elderly: an old widespread issue with novel treatment perspectives

Erectile dysfunction (ED) is one of the most common chronic diseases affecting men and its prevalence increases with aging. It is also the most frequently diagnosed sexual dysfunction in the older male population. A number of different diseases potentially worsening sexual function may occur in elderly people, together with polypharmacy. Related causes of ED are variable and can include arterial, neurogenic, hormonal, cavernosal, iatrogenic, and psychogenic causes. The aim of the present review was to examine the main aspects of erectile dysfunction going through epidemiology and pathophysiology and revise most of ED in elderly disabled men and in those affected with psychiatric disorders. Lastly we tried to focus on the main aspects of nonpharmacological and pharmacological treatments of ED and the recreational use in the elderly. Phosphodiesterase-5 inhibitors (PDE5-I) are commonly used for on-demand or chronic treatment of ED. It is widely known that PDE5-I have lower response rates in older men than in younger patients, but they have the advantages of ease of use and excellent safety profile, also in the elderly. The old and new PDE5-I as well as the alternative treatments for ED are extensively discussed.

Plant polyphenols in the treatment of age-associated diseases: revealing the pleiotropic effects of icariin by network analysis

Polyphenols are a broad class of compounds. Some are ingested in substantial quantities from nutritional sources, more are produced by medicinal plants, and some of them are taken as drugs. It is becoming clear, that a single polyphenol is impacting several cellular pathways. Thus, a network approach is becoming feasible, describing the interaction of a single polyphenol with cellular networks. Here we have selected icariin to draw a prototypic network of icariin activities. Icariin appears to be a promising drug to treat major age-related diseases, like neurodegeneration, memory and depressive disorders, chronic inflammation, diabetes, and osteoporosis. It interacts with several relevant pathways, like PDE, TGF-ß, MAPK, PPAR, NOS, IGF, Sirtuin, and others. Such networks will be useful to future comparative studies of complex effects of polyphenols.

Vasodilator compounds derived from plants and their mechanisms of action

The present paper reviews vasodilator compounds isolated from plants that were reported in the past 22 years (1990 to 2012) and the different mechanisms of action involved in their vasodilator effects. The search for reports was conducted in a comprehensive manner, intending to encompass those metabolites with a vasodilator effect whose mechanism of action involved both vascular endothelium and arterial smooth muscle. The results obtained from our bibliographic search showed that over half of the isolated compounds have a mechanism of action involving the endothelium. Most of these bioactive metabolites cause vasodilation either by activating the nitric oxide/cGMP pathway or by blocking voltage-dependent calcium channels. Moreover, it was found that many compounds induced vasodilation by more than one mechanism. This review confirms that secondary metabolites, which include a significant group of compounds with extensive chemical diversity, are a valuable source of new pharmaceuticals useful for the treatment and prevention of cardiovascular diseases.

Icariin potentiates the antitumor activity of gemcitabine in gallbladder cancer by suppressing NF-κB

AIM

Gemcitabine has been increasingly prescribed for the treatment of gallbladder cancer. However, the response rate is low. The aim of this study is to determine whether icariin, a flavonoid isolated from Epimedi herba, could potentiate the antitumor activity of gemcitabine in gallbladder cancer.

METHODS

Human gallbladder carcinoma cell lines GBC-SD and SGC-996 were tested. Cell proliferation and apoptosis were analyzed using MTT assay and flow cytometry, respectively. The expression of apoptosis- and proliferation-related molecules was detected with Western blotting. Caspase-3 activity was analyzed using colorimetric assay, and NF-κB activity was measured with ELISA. A gallbladder cancer xenograft model was established in female BALB/c (nu/nu) mice. The mice were intraperitoneally administered gemcitabine (125 mg/kg) in combination with icariin (40 mg/kg) for 2 weeks.

RESULTS

Icariin (40-160 μg/mL) dose-dependently suppressed cell proliferation and induced apoptosis in both GBC-SD and SGC-996 cells, with SGC-996 cells being less sensitive to the drug. Icariin (40 μg/mL) significantly enhanced the antitumor activity of gemcitabine (0.5 μmol/L) in both GBC-SD and SGC-996 cells. The mice bearing gallbladder cancer xenograft treated with gemcitabine in combination with icariin exhibited significantly smaller tumor size than the mice treated with either drug alone. In GBC-SD cells, icariin significantly inhibited both the constitutive and gemcitabine-induced NF-κB activity, enhanced caspase-3 activity, induced G(0)-G(1) phase arrest, and suppressed the expression of Bcl-2, Bcl-xL and surviving proteins.

CONCLUSION

Icariin, by suppressing NF-κB activity, exerts antitumor activity, and potentiates the antitumor activity of gemcitabine in gallbladder cancer. Combined administration of gemcitabine and icariin may offer a better therapeutic option for the patients with gallbladder cancer.

Drug-Drug Interactions Potential of Icariin and Its Intestinal Metabolites via Inhibition of Intestinal UDP-Glucuronosyltransferases

Icariin is known as an indicative constituent of the Epimedium genus, which has been commonly used in Chinese herbal medicine to enhance treat impotence and improve sexual function, as well as for several other indications for over 2000 years. In this study, we aimed to investigate the effects of icariin and its intestinal metabolites on the activities of human UDP-glucuronosyltransferase (UGT) activities. Using a panel of recombinant human UGT isoforms, we found that icariin exhibited potent inhibition against UGT1A3. It is interesting that the intestinal metabolites of icariin exhibited a different inhibition profile compared with icariin. Different from icariin, icariside II was a potent inhibitor of UGT1A4, UGT1A7, UGT1A9, and UGT2B7, and icaritin was a potent inhibitor of UGT1A7 and UGT1A9. The potential for drug interactions in vivo was also quantitatively predicted and compared. The quantitative prediction of risks indicated that in vivo inhibition against intestinal UGT1A3, UGT1A4, and UGT1A7 would likely occur after oral administration of icariin products.

Anti-Proliferative Efficacy of Icariin on HepG2 Hepatoma and Its Possible Mechanism of Action

The aim of the present work was to explore the anti-hepatoma effects of icariin both in vitro and in vivo and to elucidate its potential mechanism of action. The MTT assay was applied to test the anti-proliferative effects of icariin in vitro. HepG2 bearing NMRI nu/nu mice were used to test the anticancer effects of icariin in vivo. Immunohistochemical assay and flow cytometry assay (FACS) were applied to detect the possible mechanisms of action of icariin. MTT assay illustrated that icariin inhibited the proliferation of HepG2 cells in a concentration dependent manner; meanwhile, icariin inhibited the tumor growth in HepG2 bearing NMRI nu/nu mice. The tumor weight was inhibited by 55.6% and tumor volume was inhibited by 47.2%. Icariin did not influence the spleen and body weights or blood parameters. Immunohistochemical analysis indicated that the expressions of both CD31 and Ki67 in the icariin treated group were significantly lower than those in the control group (p < 0.01). FACS assay showed that icariin dramatically decreased the percentage of CD4+ and CD8+ cells in bone marrow and CD19+ cells in blood on day 8. On day 17, the percentage of CD8+ cells in blood was lower than those in the control group. CD4/CD8 ratio in icariin group was significantly elevated in bone marrow on day 17. Icariin showed anticancer efficacy both in vitro and in vivo. The possible mechanism of action could be related to its anti-angiogenesis and anti-proliferative effects in tumors.

Effects of flavonoids and other polyphenols on inflammation

Flavonoids are a family of polyphenolic compounds which are widespread in nature (vegetables) and are consumed as part of the human diet in significant amounts. There are other types of polyphenols, including, for example, tannins and resveratrol. Flavonoids and related polyphenolic compounds have significant antiinflammatory activity, among others. This short review summarizes the current knowledge on the effects of flavonoids and related polyphenolic compounds on inflammation, with a focus on structural requirements, the mechanisms involved, and pharmacokinetic considerations. Different molecular (cyclooxygenase, lipoxygenase) and cellular targets (macrophages, lymphocytes, epithelial cells, endothelium) have been identified. In addition, many flavonoids display significant antioxidant/radical scavenging properties. There is substantial structural variation in these compounds, which is bound to have an impact on their biological profile, and specifically on their effects on inflammatory conditions. However, in general terms there is substantial consistency in the effects of these compounds despite considerable structural variations. The mechanisms have been studied mainly in myeloid cells, where the predominant effect is an inhibition of NF-κB signaling and the downregulation of the expression of proinflammatory markers. At present there is a gap in knowledge of in vitro and in vivo effects, although the pharmacokinetics of flavonoids has advanced considerably in the last decade. Many flavonoids have been studied for their intestinal antiinflammatory activity which is only logical, since the gastrointestinal tract is naturally exposed to them. However, their potential therapeutic application in inflammation is not restricted to this organ and extends to other sites and conditions, including arthritis, asthma, encephalomyelitis, and atherosclerosis, among others.

Icariin attenuates cardiac remodelling through down-regulating myocardial apoptosis and matrix metalloproteinase activity in rats with congestive heart failure

Objectives

In this study, the anti-heart failure effect of icariin, a natural flavonol glycoside, and the underlying mechanisms were investigated.

Methods

Heart failure was induced by isoproterenol in male Sprague–Dawley rats. Matrix metalloproteinase activity was determined by gelatin zymography assay. The mRNA expression was determined by real-time PCR. The protein expression was determined by Western bolt. Mitochondria structure was examined by transmission electron microscopy.

Key findings

Isoproterenol administration resulted in a severe heart failure, as shown by the increased levels of left ventricular weight index, heart rate, left ventricular end diastolic pressure, maximal rate of left ventricular pressure decline (dp/dtmin), decreased levels of left ventricular systolic pressure and maximal rate of left ventricular pressure rise (dp/dtmax). Against these, icariin dose-dependently reversed the changes of these cardiac morphometric and haemodynamic parameters. In addition, icariin significantly inhibited serum levels of tumour necrosis factor-α, noradrenaline, angiotensin II and brain natriuretic peptide in rats with congestive hear failure and improved the histological changes, including cardiocyte hypertrophy, cardiocyte degeneration, inflammatory infiltration and cardiac desmoplasia. Furthermore, the expression and activity of matrix metalloproteinase (MMP)-2 and MMP-9, which regulate collagen production, were also blocked by icariin. Moreover, myocardial apoptosis was remarkably attenuated by icariin through regulating Bcl-2/Bax axle.

Conclusions

Icariin ameliorates left ventricular dysfunction and cardiac remodelling through down-regulating matrix metalloproteinase-2 and 9 activity and myocardial apoptosis in rats with congestive heart failure.

Effect of prostaglandin E1 on TNF-induced vascular inflammation in human umbilical vein endothelial cells

Prostaglandin E1 (PGE1) is a member of the prostaglandins and has a variety of cardiovascular protective effects. Increasing attention has been paid to the anti-inflammation activity of PGE1, but little direct evidence has been found. We investigated the effects of PGE1 on cell adhesion and inflammation and the mechanisms responsible for this activity in tumor necrosis factor (TNF)-treated human umbilical vein endothelial cells. Results demonstrated that pretreatment with PGE1 decreased the adhesion between vascular endothelial cells and monocytes, reduced the expression of vascular cell adhesion molecule-1, intercellular adhesion molecule-1, and E-selectin in vascular endothelial cells. In addition, PGE1 suppressed TNF-induced NF-kappaB activation and production of reactive oxygen species. We concluded that PGE1 suppressed the vascular inflammatory process, which might be closely related to the inhibition of reactive oxygen species and NF-kappaB activation in human umbilical vein endothelial cells.

Protective effects of icariin on brain dysfunction induced by lipopolysaccharide in rats

In this study we examined the protective effects of icariin, a flavonol isolated from Herba epimedii, on learning and memory in a rat model with brain inflammation induced by lipopolysaccharide (LPS). Injecting LPS into the lateral ventricle caused rat brain dysfunction, as evidenced by deficits of spatial learning and memory in the Morris water maze. With administration of icariin (30, 60, 120mg/kg body wt./day) for 17 consecutive days, spatial learning and memory abilities were markedly altered. Escape latency and searching distance decreased, and the expressions of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and cyclooxygenase-2 (COX-2) of brain were significantly reduced as observed by real-time RT-PCR and immunohistochemistry. This study used ibuprofen (40mg/kg body wt./day) as positive control. In conclusion, this study suggested that icariin can improve spatial learning and memory abilities in rats with brain dysfunction induced by LPS, an effect which may be due to decreased expressions of TNF-α, IL-1β and COX-2 in the hippocampus.

Icariin, a natural flavonol glycoside, induces apoptosis in human hepatoma SMMC-7721 cells via a ROS/JNK-dependent mitochondrial pathway

In this study, the anticancer effect of icariin, a natural flavonol glycoside, against human hepatoma SMMC-7721 cells and the underlying mechanisms were investigated. Icariin triggered the mitochondrial/caspase apoptotic pathway indicated by enhanced Bax-to-Bcl-2 ratio, loss of mitochondrial membrane potential, cytochrome c release, and caspase cascade. Moreover, icariin induced a sustained activation of the phosphorylation of c-Jun N-terminal kinase (JNK) but not p38 and ERK1/2, and SP600125 (an inhibitor of JNK) almost reversed icariin-induced apoptosis in SMMC-7721 cells. In addition, icariin provoked the generation of reactive oxygen species (ROS) in SMMC-7721 cells, while the antioxidant N-acetyl cysteine almost completely blocked icariin-induced JNK activation and apoptosis. Taken together, these findings suggest that icariin induces apoptosis through a ROS/JNK-dependent mitochondrial pathway.