Novel herbal flavonoids promote apoptosis but differentially induce cell cycle arrest in human colon cancer cell

Immunopromoter improves liver apoptosis and immune response in Shaoxing ducklings

Antibiotics as feed additives, play a vital role in animal husbandry. However, overused antibiotics could cause endogenous infections in animals, and even endanger human health through the food chain. And immunopotentiators can make the low immune function improve and accelerate the induction of immune response. The aim of this study was to investigate the effects of five different immunopotentiators on the expression of liver apoptosis and immune factor related genes in Shaoxing ducklings (Anas Platyrhynchos). A total of 150 one-day-old Shaoxing ducklings were randomly divided into six groups including saline, chlorogenic acid, β-D-glucan, astragalus flavone, CpG DNA and chicken IgG, which were injected subcutaneously into the neck, respectively. At 18 days old, the liver tissues were collected to detecte the mRNA and protein expression levels of inflammatory and apoptosis-related genes. The results showed that compared with the control group, the mRNA and protein levels of liver Bcl2 with chlorogenic acid, β-D-glucan, astragalus flavone, CpG-DNA and chicken IgG were significantly decreased (p < 0.05), while the expression level of Caspase3 was up-regulated in some different degrees. In addition,The expression levels of liver iNOS and COX2 were significantly increased after the injection of five immunopotentiators (p < 0.05), and the mRNA levels of IFN-α, IFN-β, IL-1β, RIG-I, TLR3 and TLR7 genes were also significantly up-regulated compared with the control group (p < 0.05). In conclusion, chlorogenic acid, β-D-glucan, astragalus flavone, CpG-DNA and chicken IgG can be used as immunopotentiators to regulate duck innate immunity. This study provides a new way to prevent important infectious diseases of ducks, and also provides a certain reference for the application of antibiotic substitutes in animal production.

Natural Chalcones and Derivatives in Colon Cancer: Pre-Clinical Challenges and the Promise of Chalcone-Based Nanoparticles

Colon cancer poses a complex and substantial global health challenge, necessitating innovative therapeutic approaches. Chalcones, a versatile class of compounds with diverse pharmacological properties, have emerged as promising candidates for addressing colon cancer. Their ability to modulate pivotal signaling pathways in the development and progression of colon cancer makes them invaluable as targeted therapeutics. Nevertheless, it is crucial to recognize that although chalcones exhibit promise, further pre-clinical studies are required to validate their efficacy and safety. The journey toward effective colon cancer treatment is multifaceted, involving considerations such as optimizing the sequencing of therapeutic agents, comprehending the resistance mechanisms, and exploring combination therapies incorporating chalcones. Furthermore, the integration of nanoparticle-based drug delivery systems presents a novel avenue for enhancing the effectiveness of chalcones in colon cancer treatment. This review delves into the mechanisms of action of natural chalcones and some derivatives. It highlights the challenges associated with their use in pre-clinical studies, while also underscoring the advantages of employing chalcone-based nanoparticles for the treatment of colon cancer.

Iron-Dependent Cell Death: A New Treatment Approach against Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a devastating tumor type where a very high proportion of people diagnosed end up dying from cancer. Surgical resection is an option for only about 20% of patients, where the 5-year survival increase ranges from 10 to 25%. In addition to surgical resection, there are adjuvant chemotherapy schemes, such as FOLFIRINOX (a mix of Irinotecan, oxaliplatin, 5-Fluorouraci and leucovorin) or gemcitabine-based treatment. These last two drugs have been compared in the NAPOLI-3 clinical trial, and the NALIRIFOX arm was found to have a higher overall survival (OS) (11.1 months vs. 9.2 months). Despite these exciting improvements, PDAC still has no effective treatment. An interesting approach would be to drive ferroptosis in PDAC cells. A non-apoptotic reactive oxygen species (ROS)-dependent cell death, ferroptosis was first described by Dixon et al. in 2012. ROS are constantly produced in the tumor cell due to high cell metabolism, which is even higher when exposed to chemotherapy. Tumor cells have detoxifying mechanisms, such as Mn-SOD or the GSH-GPX system. However, when a threshold of ROS is exceeded in the tumor cell, the cell's antioxidant systems are overwhelmed, resulting in lipid peroxidation and, ultimately, ferroptosis. In this review, we point out ferroptosis as an approach to consider in PDAC and propose that altering the cellular ROS balance by combining oxidizing agents or with inhibitors of the main cellular detoxifiers triggers ferroptosis in PDAC.

M, K M, Dey T, Zargar MI, Singh J. Recent advance of herbal medicines in cancer- a molecular approach

Bioactive compounds are crucial for an extensive range of therapeutic uses, and some exhibit anticancer activity. Scientists advocate that phytochemicals modulate autophagy and apoptosis, involved in the underlying pathobiology of cancer development and regulation. The pharmacological aiming of the autophagy-apoptosis signaling pathway using phytocompounds hence offers an auspicious method that is complementary to conventional cancer chemotherapy. The current review aims to explore the molecular level of the autophagic-apoptotic pathway to know its implication in the pathobiology of cancer and explore the essential cellular process as a druggable anticancer target and therapeutic emergence of naturally derived phytocompound-based anticancer agents. The data in the review were collected from scientific databases such as Google search, Web of Science, PubMed, Scopus, Medline, and Clinical Trials. With a broad outlook, we investigated their cutting-edge scientifically revealed and/or searched pharmacologic effects, a novel mechanism of action, and molecular signaling pathway of phytochemicals in cancer therapy. In this review, the evidence is focused on molecular pharmacology, specifically caspase, Nrf2, NF-kB, autophagic-apoptotic pathway, and several mechanisms to understand their role in cancer biology.

Isoliquiritigenin inhibits pancreatic cancer progression through blockade of p38 MAPK-regulated autophagy

BACKGROUND

Pancreatic cancer has been characterized by poor prognosis, early metastasis and dissatisfactory treatment outcome. The high basal level of autophagy in tumor cells leads to chemoresistance and tumor progression. Thus, it is imminent to explore novel effective chemotherapeutic adjuvants to increase patients' survival rate. Isoliquiritigenin (ISL) is a bioactive flavonoid obtained from the Traditional Chinese herbal medicine Glycyrrhiza glabra, and it possesses a broad range of pharmacological effects. In this study, the anti-cancer effect of ISL in pancreatic cancer treatment and the underlying mechanism are investigated.

METHODS

MTT assay, colony formation and EdU analysis were performed to explore the growth inhibition of ISL on pancreatic cancer cells. Apoptosis were analyzed using TUNEL and flow cytometry. The formations of autophagosomes were analyzed by immunofluorescence microscopy and transmission electron microscopy. RFP-GFP-LC3B probe was applied to detect the autophagy flux. To assess the structural interaction of ISL with p38 protein, molecular docking assays were performed. The molecular mechanism was elucidated by using western immunoblotting. Subsequently, the inhibition of ISL on tumor growth was determined in vivo using pancreatic tumor mice model.

RESULTS

ISL inhibited pancreatic cancer cell growth and induced apoptosis, both in vitro and in vivo. ISL caused accumulation of autophagosome through blockade of late stage autophagic flux. Moreover, autophagy inducer rapamycin enhanced ISL-evoked cell growth inhibition and promoted apoptosis, while inhibition of autophagosome formation by siAtg5 attenuated ISL-induced apoptosis. It is remarkable that ISL synergistically sensitized the cytotoxic effect of gemcitabine and 5-fluorouracil on pancreatic cancer cells as both drugs induced autophagy. Molecular docking analysis has indicated that ISL acted by direct targeting of p38 MAPK, which was confirmed by ISL-induced phosphorylation of p38. The autophagy flux induced by p38 inhibitor SB203580 was blocked by ISL, with further increasing toxicity of ISL in pancreatic cancer cells.

CONCLUSION

The results have revealed that ISL inhibited pancreatic cancer progression by blockade of autophagy through p38 MAPK signaling.

Therapeutic Intervention in Cancer by Isoliquiritigenin from Licorice: A Natural Antioxidant and Redox Regulator

Oxidative stress could lead to a variety of body dysfunctions, including neurodegeneration and cancer, which are closely associated with intracellular signal transducers such as reactive oxygen species (ROS). It has been suggested that ROS is the upstream regulator of autophagy, and that it provides a negative feedback regulation to remove oxidative damage. Defects in the ROS-autophagic redox homeostasis could lead to the increased production of ROS and the accumulation of damaged organelles that in turn promote metabolic reprogramming and induce tumorigenesis. One significant characteristic of pancreatic cancer is the reprogramming of cellular energy metabolism, which facilitates the rapid growth, invasiveness, and the survival of cancer cells. Thus, the rectification of metabolic dysfunction is essential in therapeutic cancer targeting. Isoliquiritigenin (ISL) is a chalcone obtained from the plant Glycyrrhiza glabra, which is a powdered root licorice that has been consumed for centuries in different regions of the world. ISL is known to be a natural antioxidant that possesses diversified functions, including redox regulation in cells. This review contains discussions on the herbal source, biological properties, and anticancer potential of ISL. This is the first time that the anticancer activities of ISL in pancreatic cancer has been elucidated, with a coverage of the involvement of antioxidation, metabolic redox regulation, and autophagy in pancreatic cancer development. Furthermore, some remarks on related compounds of the isoflavonoid biosynthetic pathway of ISL will also be discussed.

Glycyrrhiza glabra (Licorice): A Comprehensive Review on Its Phytochemistry, Biological Activities, Clinical Evidence and Toxicology

There are more than 30 species of Glycyrrhiza genus extensively spread worldwide. It was the most prescribed herb in Ancient Egyptian, Roman, Greek, East China, and the West from the Former Han era. There are various beneficial effects of licorice root extracts, such as treating throat infections, tuberculosis, respiratory, liver diseases, antibacterial, anti-inflammatory, and immunodeficiency. On the other hand, traditional medicines are getting the attraction to treat many diseases. Therefore, it is vital to screen the medicinal plants to find the potential of new compounds to treat chronic diseases such as respiratory, cardiovascular, anticancer, hepatoprotective, etc. This work comprehensively reviews ethnopharmacological uses, phytochemistry, biological activities, clinical evidence, and the toxicology of licorice, which will serve as a resource for future clinical and fundamental studies. An attempt has been made to establish the pharmacological effect of licorice in different diseases. In addition, the focus of this review article is on the molecular mechanism of licorice extracts and their four flavonoids (isoliquiritigenin, liquiritigenin, lichalocone, and glabridin) pharmacologic activities. Licorice could be a natural alternative for current therapy to exterminate new emerging disorders with mild side effects. This review will provide systematic insights into this ancient drug for further development and clinical use.

Cancer Therapy Challenge: It Is Time to Look in the "St. Patrick's Well" of the Nature

Cancer still remains a leading cause of death despite improvements in diagnosis, drug discovery and therapy approach. Therefore, there is a strong need to improve methodologies as well as to increase the number of approaches available. Natural compounds of different origins (i.e., from fungi, plants, microbes, etc.) represent an interesting approach for fighting cancer. In particular, synergistic strategies may represent an intriguing approach, combining natural compounds with classic chemotherapeutic drugs to increase therapeutic efficacy and lower the required drug concentrations. In this review, we focus primarily on those natural compounds utilized in synergistic approached to treating cancer, with particular attention to those compounds that have gained the most research interest.

Natural Products in the Prevention of Metabolic Diseases: Lessons Learned from the 20th KAST Frontier Scientists Workshop

The incidence of metabolic and chronic diseases including cancer, obesity, inflammation-related diseases sharply increased in the 21st century. Major underlying causes for these diseases are inflammation and oxidative stress. Accordingly, natural products and their bioactive components are obvious therapeutic agents for these diseases, given their antioxidant and anti-inflammatory properties. Research in this area has been significantly expanded to include chemical identification of these compounds using advanced analytical techniques, determining their mechanism of action, food fortification and supplement development, and enhancing their bioavailability and bioactivity using nanotechnology. These timely topics were discussed at the 20th Frontier Scientists Workshop sponsored by the Korean Academy of Science and Technology, held at the University of Hawaii at Manoa on 23 November 2019. Scientists from South Korea and the U.S. shared their recent research under the overarching theme of Bioactive Compounds, Nanoparticles, and Disease Prevention. This review summarizes presentations at the workshop to provide current knowledge of the role of natural products in the prevention and treatment of metabolic diseases.

Perspectives on the Role of Isoliquiritigenin in Cancer

Isoliquiritigenin (2',4',4-trihydroxychalcone, ISL), one of the most important bioactive compounds with a chalcone structure, is derived from licorice root. Licorice is commonly known as Glycyrrhiza, including Glycyrrhiza uralensis, Glycyrrhiza radix, and Glycyrrhiza glabra, which are generally available in common foods and Chinese herbal medicines based on a wide variety of biological functions and pharmacological effects, and its derivative (ISL) is utilized as a food additive and adjunct disease treatment. In this review, we summarized the progress over the last 10 years in the targeted pathways and molecular mechanisms of ISL that are involved in the regulation of the onset and progression of different types of cancers.

Chinese herbal medicines for prevention and treatment of colorectal cancer: From molecular mechanisms to potential clinical applications

Worldwide, colorectal cancer (CRC) is one of the most common malignant tumors, leading to immense social and economic burdens. Currently, the main treatments for CRC include surgery, chemotherapy, radiotherapy and immunotherapy. Despite advances in the diagnosis and treatment of CRC, the prognosis for CRC patients remains poor. Furthermore, the occurrence of side effects and toxicities severely limits the clinical use of these therapies. Therefore, alternative medications with high efficacy but few side effects are needed. An increasing number of modern pharmacological studies and clinical trials have supported the effectiveness of Chinese herbal medicines (CHMs) for the prevention and treatment of CRC. CHMs may be able to effectively reduce the risk of CRC, alleviate the adverse reactions caused by chemotherapy, and prolong the survival time of patients with advanced CRC. Studies of molecular mechanisms have provided deeper insight into the roles of molecules from CHMs in treating CRC. This paper summarizes the current understanding of the use of CHMs for the prevention and treatment of CRC, the main molecular mechanisms involved in these processes, the role of CHMs in modulating chemotherapy-induced adverse reactions, and CHM's potential role in epigenetic regulation of CRC. The current study provides beneficial information on the use of CHMs for the prevention and treatment of CRC in the clinic, and suggests novel directions for new drug discovery against CRC.

Functional Group-Dependent Induction of Astrocytogenesis and Neurogenesis by Flavone Derivatives

Neural stem cells (NSCs) differentiate into multiple cell types, including neurons, astrocytes, and oligodendrocytes, and provide an excellent platform to screen drugs against neurodegenerative diseases. Flavonoids exert a wide range of biological functions on several cell types and affect the fate of NSCs. In the present study, we investigated whether the structure-activity relationships of flavone derivatives influence NSC differentiation. As previously reported, we observed that PD98059 (2′-amino-3′-methoxy-flavone), compound 2 (3′-methoxy-flavone) induced astrocytogenesis. In the present study, we showed that compound 3 (2′-hydroxy-3′-methoxy-flavone), containing a 3′-methoxy group, and a non-bulky group at C2′ and C4′, induced astrocytogenesis through JAK-STAT3 signaling pathway. However, compound 1 and 7–12 without the methoxy group did not show such effects. Interestingly, the compounds 4 (2′,3′-dimethoxyflavone), 5 (2′-N-phenylacetamido-3′-methoxy-flavone), and 6 (3′,4′-dimethoxyflavone) containing 3′-methoxy could not promote astrocytic differentiation, suggesting that both the methoxy groups at C3′ and non-bulky group at C2′ and C4′ are required for the induction of astrocytogenesis. Notably, compound 6 promoted neuronal differentiation, whereas its 4′-demethoxylated analog, compound 2, repressed neurogenesis, suggesting an essential role of the methoxy group at C4′ in neurogenesis. These findings revealed that subtle structural changes of flavone derivatives have pronounced effects on NSC differentiation and can guide to design and develop novel flavone chemicals targeting NSCs fate regulation.

Formononetin: A Review of Its Anticancer Potentials and Mechanisms

Cancer, a complex yet common disease, is caused by uncontrolled cell division and abnormal cell growth due to a variety of gene mutations. Seeking effective treatments for cancer is a major research focus, as the incidence of cancer is on the rise and drug resistance to existing anti-cancer drugs is major concern. Natural products have the potential to yield unique molecules and combinations of substances that may be effective against cancer with relatively low toxicity/better side effect profile compared to standard anticancer therapy. Drug discovery work with natural products has demonstrated that natural compounds display a wide range of biological activities correlating to anticancer effects. In this review, we discuss formononetin (C₁₆H₁₂O₄), which originates mainly from red clovers and the Chinese herb Astragalus membranaceus. The compound comes from a class of 7-hydroisoflavones with a substitution of methoxy group at position 4. Formononetin elicits antitumorigenic properties in vitro and in vivo by modulating numerous signaling pathways to induce cell apoptosis (by intrinsic pathway involving Bax, Bcl-2, and caspase-3 proteins) and cell cycle arrest (by regulating mediators like cyclin A, cyclin B1, and cyclin D1), suppress cell proliferation [by signal transducer and activator of transcription (STAT) activation, phosphatidylinositol 3-kinase/protein kinase-B (PI3K/AKT), and mitogen-activated protein kinase (MAPK) signaling pathway], and inhibit cell invasion [by regulating growth factors vascular endothelial growth factor (VEGF) and Fibroblast growth factor 2 (FGF2), and matrix metalloproteinase (MMP)-2 and MMP-9 proteins]. Co-treatment with other chemotherapy drugs such as bortezomib, LY2940002, U0126, sunitinib, epirubicin, doxorubicin, temozolomide, and metformin enhances the anticancer potential of both formononetin and the respective drugs through synergistic effect. Compiling the evidence thus far highlights the potential of formononetin to be a promising candidate for chemoprevention and chemotherapy.

Modulation of osteogenic and myogenic differentiation by a phytoestrogen formononetin via p38MAPK-dependent JAK-STAT and Smad-1/5/8 signaling pathways in mouse myogenic progenitor cells

Formononetin (FN), a typical phytoestrogen has attracted substantial attention as a novel agent because of its diverse biological activities including, osteogenic differentiation. However, the molecular mechanisms underlying osteogenic and myogenic differentiation by FN in C2C12 progenitor cells remain unknown. Therefore the objective of the current study was to investigate the action of FN on myogenic and osteogenic differentiation and its impact on signaling pathways in C2C12 cells. FN significantly increased myogenic markers such as Myogenin, myosin heavy chains, and myogenic differentiation 1 (MyoD). In addition, the expression of osteogenic specific genes alkaline phosphatase (ALP), Run-related transcription factor 2(RUNX2), and osteocalcin (OCN) were up-regulated by FN treatment. Moreover, FN enhanced the ALP level, calcium deposition and the expression of bone morphogenetic protein isoform (BMPs). Signal transduction pathways mediated by p38 mitogen-activated protein kinase (p38MAPK), extracellular signal-related kinases (ERKs), protein kinase B (Akt), Janus kinases (JAKs), and signal transducer activator of transcription proteins (STATs) in myogenic and osteogenic differentiation after FN treatment were also examined. FN treatment activates myogenic differentiation by increasing p38MAPK and decreasing JAK1-STAT1 phosphorylation levels, while osteogenic induction was enhanced by p38MAPK dependent Smad, 1/5/8 signaling pathways in C2C12 progenitor cells.

Focus on Formononetin: Anticancer Potential and Molecular Targets

Formononetin, an isoflavone, is extracted from various medicinal plants and herbs, including the red clover (Trifolium pratense) and Chinese medicinal plant Astragalus membranaceus. Formononetin's antioxidant and neuroprotective effects underscore its therapeutic use against Alzheimer's disease. Formononetin has been under intense investigation for the past decade as strong evidence on promoting apoptosis and against proliferation suggests for its use as an anticancer agent against diverse cancers. These anticancer properties are observed in multiple cancer cell models, including breast, colorectal, and prostate cancer. Formononetin also attenuates metastasis and tumor growth in various in vivo studies. The beneficial effects exuded by formononetin can be attributed to its antiproliferative and cell cycle arrest inducing properties. Formononetin regulates various transcription factors and growth-factor-mediated oncogenic pathways, consequently alleviating the possible causes of chronic inflammation that are linked to cancer survival of neoplastic cells and their resistance against chemotherapy. As such, this review summarizes and critically analyzes current evidence on the potential of formononetin for therapy of various malignancies with special emphasis on molecular targets.

Formononetin inhibits colon carcinoma cell growth and invasion by microRNA‑149‑mediated EphB3 downregulation and inhibition of PI3K/AKT and STAT3 signaling pathways

Formononetin (Form), a phytoestrogen extracted from the roots of Astragalus membranaceus, is one of the fundamental herbs used in traditional Chinese medicine because of its protective effects against certain malignant tumors. However, its role in colon carcinoma cells and the underlying molecular mechanisms have not been completely elucidated. The present study aimed to demonstrate that Form significantly inhibited the proliferation and invasion of the colon carcinoma cell lines SW1116 and HCT116. Mechanistic studies have suggested that Form suppresses colon carcinoma cell growth by downregulating cell cycle-associated protein (cyclin D1) expression and arresting the cell cycle at the G₀-G₁ checkpoint. Further studies revealed that treatment with Form inhibits matrix metalloproteinase (MMP)2 and MMP9 expression. Aditionally, the results demonstrated that Form significantly increased microRNA (miR)-149 expression. Following miR-149 overexpression in SW1116 and HCT116 cells using an miR-149 mimic, cell viability and Ephrin type-B receptor 3 (EphB3) levels decreased. Furthermore, the inhibitory effects of Form were associated with phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) and signal transducer and activator of transcription 3 (STAT3) signaling pathways. These results indicated the suppressive effect of Form on colon carcinoma cell proliferation and invasion, possibly via miR-149-induced EphB3 downregulation and the inhibition of the PI3K/AKT and STAT3 signaling pathways. Overall, Form may be used as a novel candidate for the clinical treatment of colorectal cancer in the future.

Polyphenols in Colorectal Cancer: Current State of Knowledge including Clinical Trials and Molecular Mechanism of Action

Polyphenols have been reported to have wide spectrum of biological activities including major impact on initiation, promotion, and progression of cancer by modulating different signalling pathways. Colorectal cancer is the second most major cause of mortality and morbidity among females and the third among males. The objective of this review is to describe the activity of a variety of polyphenols in colorectal cancer in clinical trials, preclinical studies, and primary research. The molecular mechanisms of major polyphenols related to their beneficial effects on colorectal cancer are also addressed. Synthetic modifications and other future directions towards exploiting of natural polyphenols against colorectal cancer are discussed in the last section.

Anti-Aging Implications of Astragalus Membranaceus (Huangqi): A Well-Known Chinese Tonic

Owing to a dramatic increase in average life expectancy and the Family Planning program of the 1970s - 1990s, China is rapidly becoming an aging society. Therefore, the investigation of healthspan-extending drugs becomes more urgent. Astragalus membranaceus (Huangqi) is a major medicinal herb that has been commonly used in many herbal formulations in the practice of traditional Chinese medicine (TCM) to treat a wide variety of diseases and body disorders, or marketed as life-prolonging extracts for human use in China, for more than 2000 years. The major components of Astragalus membranaceus are polysaccharides, flavonoids, and saponins. Pharmacological research indicates that the extract component of Astragalus membranaceus can increase telomerase activity, and has antioxidant, anti-inflammatory, immunoregulatory, anticancer, hypolipidemic, antihyperglycemic, hepatoprotective, expectorant, and diuretic effects. A proprietary extract of the dried root of Astragalus membranaceus, called TA-65, was associated with a significant age-reversal effect in the immune system. Our review focuses on the function and the underlying mechanisms of Astragalus membranaceus in lifespan extension, anti-vascular aging, anti-brain aging, and anti-cancer effects, based on experimental and clinical studies.

Isoliquiritigenin inhibits the proliferation of human renal carcinoma Caki cells through the ROS-mediated regulation of the Jak2/STAT3 pathway

Isoliquiritigenin (ISL) is a flavonoid with chalcone structure that has been noted in licorice and shallot, which are generally used in traditional Chinese medicine. ISL has demonstrated various pharmacological effects including antioxidant, anti-inflammatory and antitumor activity. However, the molecular mechanisms underlying the anticancer effects of ISL remain poorly understood. The present study revealed that ISL significantly decreased viability and induced apoptosis in human renal carcinoma Caki cells. The ISL-induced apoptosis was associated with the cleavage of caspase-9, -7 and -3, and that of PARP. Moreover, ISL increased the expression of pro-apoptotic protein Bax and diminished the expression of anti-apoptotic protein Bcl-2, and Bcl-xl, thereby increasing cytochrome c release. Treatment of cells with ISL also induced the expression of p53 through downregulation of murine double minute 2 (Mdm2). Furthermore, ISL generated reactive oxygen species (ROS), and pretreatment with ROS scavenger N-acetyl cysteine (NAC) and NADPH oxidase inhibitor diphenyleneiodonium abrogated the ISL-induced apoptosis. One of the key oncogenic signaling pathways is mediated through signal transducer and activator of transcription 3 (STAT3), which promotes abnormal cell proliferation. Incubation of cells with ISL markedly diminished phosphorylation and DNA binding activity of STAT3, and reduced expression of STAT3 responsive gene products, such as cyclin D1 and D2. ISL also attenuated constitutive phosphorylation of upstream kinase, Janus-activated kinase 2 (Jak2). Pretreatment with NAC abrogated the inhibitory effect of ISL on activation of STAT3 and blocked the cleavage of caspase-9, -7 and -3, and that of PARP in Caki cells. Taken together, the present study provides the first report that ISL induces apoptosis in Caki cells via generation of ROS, which causes induction of p53 and inhibition of the STAT3 signaling pathway.

Insight into the molecular mechanism of P-glycoprotein mediated drug toxicity induced by bioflavonoids: an integrated computational approach

In this work, molecular docking, pharmacophore modeling and molecular dynamics (MD) simulation were rendered for the mouse P-glycoprotein (P-gp) (code: 4Q9H) and bioflavonoids; amorphigenin, chrysin, epigallocatechin, formononetin and rotenone including a positive control; verapamil to identify protein-ligand interaction features including binding affinities, interaction characteristics, hot-spot amino acid residues and complex stabilities. These flavonoids occupied the same binding site with high binding affinities and shared the same key residues for their binding interactions and the binding region of the flavonoids was revealed that overlapped the ATP binding region with hydrophobic and hydrophilic interactions suggesting a competitive inhibition mechanism of the compounds. Root mean square deviations (RMSDs) analysis of MD trajectories of the protein-ligand complexes and NBD2 residues, and ligands pointed out these residues were stable throughout the duration of MD simulations. Thus, the applied preliminary structure-based molecular modeling approach of interactions between NBD2 and flavonoids may be gainful to realize the intimate inhibition mechanism of P-gp at NBD2 level and on the basis of the obtained data, it can be concluded that these bioflavonoids have the potential to cause herb-drug interactions or be used as lead molecules for the inhibition of P-gp (as anti-multidrug resistance agents) via the NBD2 blocking mechanism in future.

SH003 suppresses breast cancer growth by accumulating p62 in autolysosomes

Drug markets revisits herbal medicines, as historical usages address their therapeutic efficacies with less adverse effects. Moreover, herbal medicines save both cost and time in development. SH003, a modified version of traditional herbal medicine extracted from Astragalus membranaceus (Am), Angelica gigas (Ag), and Trichosanthes Kirilowii Maximowicz (Tk) with 1:1:1 ratio (w/w) has been revealed to inhibit tumor growth and metastasis on highly metastatic breast cancer cells, both in vivo and in vitro with no toxicity. Meanwhile, autophagy is imperative for maintenance cellular homeostasis, thereby playing critical roles in cancer progression. Inhibition of autophagy by pharmacological agents induces apoptotic cell death in cancer cells, resulting in cancer treatment. In this study, we demonstrate that SH003-induced autophagy via inhibiting STAT3 and mTOR results in an induction of lysosomal p62/SQSTM1 accumulation-mediated reactive oxygen species (ROS) generation and attenuates tumor growth. SH003 induced autophagosome and autolysosome formation by inhibiting activation of STAT3- and mTOR-mediated signaling pathways. However, SH003 blocked autophagy-mediated p62/SQSTM1 degradation through reducing of lysosomal proteases, Cathepsins, resulting in accumulation of p62/SQSTM1 in the lysosome. The accumulation of p62/SQSTM1 caused the increase of ROS, which resulted in the induction of apoptotic cell death. Therefore, we conclude that SH003 suppresses breast cancer growth by inducing autophagy. In addition, SH003-induced p62/SQSTM1 could function as an important mediator for ROS generation-dependent cell death suggesting that SH003 may be useful for treating breast cancer.

A flavonoid compound from Chrysosplenium nudicaule inhibits growth and induces apoptosis of the human stomach cancer cell line SGC-7901

CONTEXT

Gastric cancer remains highly prevalent, but treatment options are limited. Natural products have proved to be a rich source of anticancer drugs. Chrysosplenium nudicaule Ledeb. (Saxifragaceae) is a perennial herb that grows in the highlands of China. It has been used as a traditional Chinese medicine to treat digestive diseases for hundreds of years. Recent studies revealed that this herb had anticancer activity, and the flavonoids were speculated to be the effective components. 6,7,3'-Trimethoxy-3,5,4'-trihydroxy flavone (TTF) and 5,4'-dihydroxy-3,6,3'trimethoxy-flavone-7-O-β-d-glucoside (DTFG) are flavonoid compounds isolated from Chrysosplenium nudicaule.

OBJECTIVE

This study examined the effect of TTF and DTFG on SGC-7901 human stomach cancer cell in vitro to determine the anticancer and induction of apoptosis properties of TTF.

MATERIALS AND METHODS

The proliferation of cells treated with 32, 16, 8, 4, and 2 μg/mL of TTF or DTFG for 24, 48, and 72 h was assessed by the MTT assay. After being treated with TTF, the apoptosis of SGC-7901 cells was assessed by acridine orange staining, ultrastructure, electrophoresis of DNA fragmentation, and flow cytometry.

RESULTS

Results indicated that TTF inhibited the growth of cancer cells with an IC50 value of 8.33 μg/mL after 72 h incubation. However, DTFG showed no inhibitory effect on the growth of the cancer cell. Further studies on TTF also confirmed that it was able to induce apoptosis of SGC-7901 cells at a concentration as low as 4 μg/mL.

DISCUSSION AND CONCLUSION

The apoptotic effect of TTF makes it a promising candidate for future chemotherapeutic application in treating stomach cancer.

Astragalus membranaceus: A Review of its Protection Against Inflammation and Gastrointestinal Cancers

Astragalus membranaceus is a major medicinal herb commonly used in many herbal formulations in the practice of traditional Chinese medicine (TCM) to treat a wide variety of diseases and body disorders. Among its diversified clinical applications, the potential use of this herb and its chemical constituents in treatments of inflammatory diseases and cancers has been actively investigated in recent years. Astragalus-based treatments have demonstrated significant amelioration of the toxicity induced by other concurrently administered orthodox drugs (e.g., immunosuppressants and cancer chemotherapeutics). The major components of Astragalus membranaceus are polysaccharides, flavonoids, and saponins. Contemporary use of Astragalus membranaceus mainly focuses on its immunomodulating, anti-oxidant, and anti-inflammatory, as well as anticancer effects. In this paper, we summarize the properties of Astragalus membranaceus and its major constituents in the biological system based on experimental and clinical studies. The antitumorigenic mechanisms of a novel Astragalus saponins extract called AST in treating various gastrointestinal cancers are highlighted. We discuss in detail how the Astragalus herb and AST influence the immune system, modulate various cancer signaling pathways, and interact with specific transcription molecules during protection against gastrointestinal inflammation and cancers. This information could help clinicians and scientists develop novel target-specific and effective therapeutic agents that are deprived of major systemic side effects, so as to establish a better treatment regimen in the battle against inflammatory diseases and cancers of the gut.

Cytotoxic Evaluation against Breast Cancer Cells of Isoliquiritigenin Analogues from Spatholobus suberectus and Their Synthetic Derivatives

Five isoliquiritigenin analogues, including a new methylene-bridged bischalcone (1), were isolated from Spatholobus suberectus. Cytotoxicity screening of these isolates and several synthetic derivatives indicated that the introduction, removal, position modification, or glycosylation of hydroxy groups in isoliquiritigenin did not improve the resultant cytotoxicity against the MCF-7 and MDA-MB-231 human breast cancer cell lines. In addition, cyclization of OH-2' chalcones or reduction of the α,β-unsaturated carbonyl double bond decreased such cytotoxicity substantially. However, methylation of hydroxy groups resulted in a marked increase in such cytotoxic activity. Among these active isoliquiritigenin analogues, 3',4',5',4″-tetramethoxychalcone (3h) was obtained as a compound with promising cytotoxic activity.

Flavonoids from the Genus Astragalus: Phytochemistry and Biological Activity

Flavonoids, the most common plant polyphenols are widely distributed in every species and possess a broad range of pharmacological activities. The genus Astragalus is the largest in the Fabaceae family with more than 2,500 species spread. They are known to contain different metabolites such as flavonoids, saponins, and polysaccharides. Plants from the genus have been used in the traditional medicine of many countries for centuries. This paper is focused on the large group of flavonoid compounds. Details on structure as well as information about the pharmacological properties of flavonoids, isolated from Astragalus species have been discussed. This review is based on publications until the first half of 2014 and includes also the results from our phytochemical investigations of the genus.

A systematic review of anticancer effects of radix astragali

OBJECTIVE

To review the anticancer effects of Radix astragali (RA), one of the most commonly used herbs to manage cancer in East Asia, and its constituents and to provide evidence of clinical usage through previously performed clinical studies.

METHODS

Preclinical and clinical studies related to the anticancer effects of RA were searched from inception to November 2013 in electronic databases. Two reviewers independently investigated 92 eligible studies, extracted all the data of studies and appraised methodological quality of clinical trials. The studies were categorized into in vitro and in vivo experimental studies and clinical studies, and analyzed by saponins, polysaccharides, and flavonoids of RA constituents, RA fraction, and whole extract.

RESULTS

In preclinical studies, RA was reported to have tumor growth inhibitory effects, immunomodulatory effects, and attenuating adverse effects by cytotoxic agents as well as chemopreventive effects. Saponins seemed to be the main constituents, which directly contributed to suppression of tumor growth through the activation of both intrinsic and extrinsic apoptotic pathway, modulation of intracellular signaling pathway, and inhibition of invasion and angiogenesis. Flavonoids suppressed tumor growth through the similar mechanisms with saponins. Polysaccharides showed immunomodulatory effects, contributing tumor shrinkages in animal models, despite the low cytotoxicity to cancer cells. Most of the clinical studies were performed with low evidence level of study designs because of various limitations. RA whole extracts and polysaccharides of RA were reported to improve the quality of life and ameliorate myelosuppression and other adverse events induced by cytotoxic therapies.

CONCLUSION

The polysaccharides, saponins, and flavonoids of RA, and the whole extract of RA have been widely reported with their anticancer effects in preclinical studies and showed a potential application as a adjunctive cancer therapeutics with the activities of immunomodulation, anti-proliferation and attenuation of adverse effects induced by cytotoxic therapy.

Meta-Analysis of Oxaliplatin-Based Chemotherapy Combined With Traditional Medicines for Colorectal Cancer: Contributions of Specific Plants to Tumor Response

This meta-analysis evaluates the clinical evidence for the addition of traditional medicines (TMs) to oxaliplatin-based regimens for colorectal cancer (CRC) in terms of tumor response rate (TRR). Eight electronic databases were searched for randomized controlled trials of oxaliplatin-based chemotherapy combined with TMs compared to the same oxaliplatin-based regimen. Data on TRR from 42 randomized controlled trials were analyzed using Review Manager 5.1. Studies were conducted in China or Japan. Publication bias was not evident. The meta-analyses suggest that the combination of the TMs with oxaliplatin-based regimens increased TRR in the palliative treatment of CRC (risk ratio [RR] 1.31 [1.20-1.42], I(2) = 0%). Benefits were evident for both injection products (RR 1.36 [1.18-1.57], I(2) = 0%) and orally administered TMs (RR 1.27 [1.15-1.41], I(2) = 0%). Further sensitivity analysis of specific plant-based TMs found that Paeonia, Curcuma, and Sophora produced consistently higher contributions to the RR results. Compounds in each of these TMs have shown growth-inhibitory effects in CRC cell-line studies. Specific combinations of TMs appeared to produce higher contributions to TRR than the TMs individually. Notable among these was the combination of Hedyotis, Astragalus, and Scutellaria.

Isoliquiritigenin as a cause of DNA damage and inhibitor of ataxia-telangiectasia mutated expression leading to G2/M phase arrest and apoptosis in oral squamous cell carcinoma

BACKGROUND

Isoliquiritigenin (ISL), a natural compound extracted from licorice, has chemopreventive and antitumor activities. The purpose of this study was to investigate the anticancer effect of ISL on human oral squamous cell carcinoma (OSCC).

METHODS

The anti-OSCC effects of ISL were evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test, flow cytometry, reverse transcription-polymerase chain reaction, Western blotting, promoter activity, terminal deoxynucleotidyl transferase dUTP nick-end labeling assay, malignant phenotype analysis, microRNA, and xenografting.

RESULTS

ISL induced OSCC cell cycle G2/M phase arrest, apoptosis, and DNA damage. However, the DNA repair-associated ataxia telangiectasia mutated (ATM) and phospho-ATM were downregulated, ATM mRNA remained unchanged, and the downstream signals were inhibited. ATM recovered when the caspase activity was blocked by Z-DVED-FMK. A low dose of ISL inhibited OSCC malignancy in vitro and reduced the tumor size in vivo.

CONCLUSION

ATM was cleaved by ISL-activated caspase, thus inhibiting DNA repair in OSCC cells. Therefore, ISL is a promising chemopreventive agent against oral cancer. © 2015 Wiley Periodicals, Inc. Head Neck 38: E360-E371, 2016.

Benzylidenetetralones, cyclic chalcone analogues, induce cell cycle arrest and apoptosis in HCT116 colorectal cancer cells

Colorectal cancer is the third most common cancer in the world, with 1.2 million new cancer cases annually. Chalcones are secondary metabolite precursors of flavonoids that exhibit diverse biological activities, including antioxidant and antitumor activities. The aim of this study was to investigate the antiproliferative effect of new synthetic chalcone derivatives on HCT116 cells. (E)-2-(2',4'-dimethoxybenzylidene)-1-tetralone (Q705) was found to be the most active (IC50 = 3.44 ± 0.25 μM). Based on these results, this compound was chosen for further analysis of its biochemical and molecular mechanisms. Our results showed that Q705 inhibited the growth and clonogenicity of HCT116 cells. The results of a flow cytometric analyses suggested that this compound caused a significant cell cycle arrest in G2/M phase and increased the proportion of cells in the subG0/G1 phase, marker of apoptosis. Q705-induced apoptosis was confirmed by TdT-mediated dUTP nick end labelling (TUNEL) assay. Treatment of HCT116 cells with this chalcone significantly increased the caspase-3,-7 activity and resulted in cleavage of poly-ADP-ribose polymerase (PARP). Changes in the nuclear morphology such as chromatin condensation were also observed. These effects were associated with a decreased expression of bcl-xL and increased overall ratio of bax/bcl-xL mRNA levels. Immunofluorescence and qRT-PCR analysis revealed that Q705 induced H2AX histone modifications characteristic of DNA damage, disruption of microtubule organization and downregulation of tubulins. In summary, these results suggest that the cyclic chalcone analogue Q705 has potential as a new compound for colorectal cancer therapy.

FOLFOX 4 combined with herbal medicine for advanced colorectal cancer: a systematic review

This systematic review evaluates the clinical evidence for the addition of herbal medicines (HMs) to FOLFOX 4 for advanced colorectal cancer (ACRC) in terms of tumor response rate (tRR), survival, quality of life and reduction in adverse events (AEs). Seven electronic databases were searched for randomized controlled trials (RCTs) of FOLFOX4 combined with HMs compared to FOLFOX4 alone. Outcome data for 13 randomized controlled trials were analysed using Review Manager 5.1. Risk of bias for objective outcomes including tumor response and survival was judged as low. Publication bias was not evident. Meta-analyses found the addition of HMs improved tRR (RR 1.25, 95%CI 1.06-1.47, I(2)  = 0%), one year survival (RR 1.51, 95%CI 1.19-1.90, I(2)  = 0%) and quality of life in terms of Karnofsky Performance Status (KPS) gained (RR 1.84, 95%CI 1.54-2.19, I(2)  = 0%); alleviated grade 3 and 4 chemotherapy-related AEs for neutropenia (RR 0.33, 95%CI 0.18-0.60, I(2)  = 0%), nausea and vomiting (RR 0.34, 95%CI 0.17-0.67, I(2)  = 0%) and neurotoxicity (RR 0.39, 95%CI 0.15-1.00, I(2)  = 0%), compared to FOLFOX4 alone. The most frequently used herbs were Astragalus membranaceus, Panax ginseng, Atractylodes macrocephala, Poria cocos, Coix lachryma-jobi and Sophora flavescens. In experimental studies, each of these herbs has shown actions that could have contributed to improved tumor response.

Modeling long-term host cell-Giardia lamblia interactions in an in vitro co-culture system

Globally, there are greater than 700,000 deaths per year associated with diarrheal disease. The flagellated intestinal parasite, Giardia lamblia, is one of the most common intestinal pathogens in both humans and animals throughout the world. While attached to the gastrointestinal epithelium, Giardia induces epithelial cell apoptosis, disrupts tight junctions, and increases intestinal permeability. The underlying cellular and molecular mechanisms of giardiasis, including the role lamina propria immune cells, such as macrophages, play in parasite control or clearance are poorly understood. Thus far, one of the major obstacles in ascertaining the mechanisms of Giardia pathology is the lack of a functionally relevant model for the long-term study of the parasite in vitro. Here we report on the development of an in vitro co-culture model which maintains the basolateral-apical architecture of the small intestine and allows for long-term survival of the parasite. Using transwell inserts, Caco-2 intestinal epithelial cells and IC-21 macrophages are co-cultured in the presence of Giardia trophozoites. Using the developed model, we show that Giardia trophozoites survive over 21 days and proliferate in a combination media of Caco-2 cell and Giardia medium. Giardia induces apoptosis of epithelial cells through caspase-3 activation and macrophages do not abrogate this response. Additionally, macrophages induce Caco-2 cells to secrete the pro-inflammatory cytokines, GRO and IL-8, a response abolished by Giardia indicating parasite induced suppression of the host immune response. The co-culture model provides additional complexity and information when compared to a single-cell model. This model will be a valuable tool for answering long-standing questions on host-parasite biology that may lead to discovery of new therapeutic interventions.

Formononetin potentiates epirubicin-induced apoptosis via ROS production in HeLa cells in vitro

The frequent development of multidrug resistance (MDR) hampers the efficacy of available anticancer drugs in treating cervical cancer. In this study, we aimed to use formononetin (7-hydroxy-4'-methoxyisoflavone), a potential herbal isoflavone, to intensify the chemosensitivity of human cervical cancer HeLa cells to epirubicin, an anticancer drug. The reactive oxygen species (ROS) levels were correlated with MDR modulation mechanisms, including the transporter inhibition and apoptosis induction. Our results revealed that formononetin significantly enhanced the cytotoxicity of epirubicin. Co-incubation of epirubicin with formononetin increased the ROS levels, including hydrogen peroxide and superoxide free radicals. Epirubicin alone markedly increased the mRNA expression of MDR1, MDR-associated protein (MRP) 1, and MRP2. In contrast, formononetin alone or combined treatment decreased the mRNA expression of MRP1 and MRP2. This result indicates that efflux transporter-mediated epirubicin resistance is inhibited at different degrees by the addition of formononetin. This isoflavone significantly intensified epirubicin uptake into HeLa cells. Apoptosis was induced by formononetin and/or epirubicin, as signified by nuclear DNA fragmentation, chromatin condensation, increased sub-G1 and G2/M phases. The cotreatment triggered the mitochondrial apoptotic pathway indicated by increased Bax-to-Bcl-2 expression ratio, loss of mitochondrial membrane potential, and significant activation of caspase-9 and -3. In addition, extrinsic/caspases-8 apoptotic pathway was also induced by the cotreatment. N-acetyl cysteine abrogated these events induced by formononetin, supporting the involvement of ROS in the MDR reversal mechanism. This study pioneered in demonstrating that formononetin may potentiate the cytotoxicity of epirubicin in HeLa cells through the ROS-mediated MRP inhibition and concurrent activation of the mitochondrial and death receptor pathways of apoptosis. Hence, the circumvention of pump and non-pump resistance using formononetin and epirubicin may pave the way for a powerful chemotherapeutic regimen for treating human cervical cancer.

Therapeutic applications of herbal medicines for cancer patients

Medicinal herbs and their derivative phytocompounds are being increasingly recognized as useful complementary treatments for cancer. A large volume of clinical studies have reported the beneficial effects of herbal medicines on the survival, immune modulation, and quality of life (QOL) of cancer patients, when these herbal medicines are used in combination with conventional therapeutics. Here, we briefly review some examples of clinical studies that investigated the use of herbal medicines for various cancers and the development of randomized controlled trials (RCTs) in this emerging research area. In addition, we also report recent studies on the biochemical and cellular mechanisms of herbal medicines in specific tumor microenvironments and the potential application of specific phytochemicals in cell-based cancer vaccine systems. This review should provide useful technological support for evidence-based application of herbal medicines in cancer therapy.

Luteolin inhibits migration of human glioblastoma U-87 MG and T98G cells through downregulation of Cdc42 expression and PI3K/AKT activity

Luteolin (3′,4′,5,7-tetrahydroxyflavone) is a common flavonoid in many types of plants and has several beneficial biological effects, including anti-inflammation, anti-oxidant, and anti-cancer properties. However, the detail mechanisms of luteolin in suppressing tumor invasion and metastasis are poorly understood. Here, we investigated the effects of luteolin on suppressing glioblastoma tumor cell invasion and migration activity. Under the non-cytotoxic doses (15 and 30 μM), luteolin exhibited an inhibitory effect on migration and invasion in U-87 MG and T98G glioblastoma cells. Additionally, filopodia assembly in U-87 MG cells was markedly suppressed after luteolin treatment. The treatment of luteolin also showed a decrease of Cdc42 (cell division cycle 42) protein levels and reduced PI3K/AKT activation, whereas there was no association between this decrease and phosphorylated ERK or altered transcription levels of Cdc42. Over expression of constitutive Cdc42 (Q61L) using transient transfection in U-87 MG cells induced a partial cell migration, but did not affected the degradation of the protein levels of Cdc42 after luteolin treatment. Moreover, inhibition of the proteaosome pathway by MG132 caused a significant recovery in the migration ability of U-87 MG cells and augmented the Cdc42 protein levels after luteolin treatment, suggesting that pharmacological inhibition of migration via luteolin treatment is likely to preferentially facilitate the protein degradation of Cdc42. Taken together, the study demonstrated that flavonoids of luteolin prevent the migration of glioblastoma cells by affecting PI3K/AKT activation, modulating the protein expression of Cdc42 and facilitating their degradation via the proteaosome pathway.

Effect of formononetin on mechanical properties and chemical composition of bones in rats with ovariectomy-induced osteoporosis

Formononetin is a naturally occurring isoflavone, which can be found in low concentrations in many dietary products, but the greatest sources of this substance are Astragalus membranaceus, Trifolium pratense, Glycyrrhiza glabra, and Pueraria lobata, which all belong to Fabaceae family. Due to its structural similarity to 17β-estradiol, it can mimic estradiol's effect and therefore is considered as a “phytoestrogen.” The aim of this study was to examine the effect of formononetin on mechanical properties and chemical composition of bones in rats with ovariectomy-induced osteoporosis. 12-week-old female rats were divided into 4 groups: sham-operated, ovariectomized, ovariectomized treated with estradiol (0.2 mg/kg) and ovariectomized treated with formononetin (10 mg/kg). Analyzed substances were administered orally for 4 weeks. Ovariectomy caused osteoporotic changes, which can be observed in bone biomechanical features (decrease of maximum load and fracture load and increase of displacements for maximum and fracture loads) and bone chemical composition (increase of water and organic fraction content, while a decrease of minerals takes place). Supplementation with formononetin resulted in slightly enhanced bone mechanical properties and bone chemistry improvement (significantly lower water content and insignificantly higher mineral fraction content). To summarize, administration of formononetin to ovariectomized rats shows beneficial effect on bone biomechanical features and chemistry; thus, it can prevent osteoporosis development.

Novel plant-derived target drugs: a step forward from licorice?

Isoliquiritigenin (ISL) is a chalcone compound with valuable pharmacological properties such as antioxidant, anti-inflammatory, anticancer and anti-allergic activities. With regard to anticancer property, ISL was able to suppress HIF-1α level, VEGF expression and secretion, cell migration and to decrease the expression and secretion of MMP-9/-2. These effects may be mediated through inhibition of p38, PI3K/Akt and NF-κB signaling pathways. Thus, low concentration of ISL may have therapeutic potential in the treatment of aggressive breast carcinoma and other neoplasms.

Isoliquiritigenin inhibits proliferation and induces apoptosis of U87 human glioma cells in vitro

Isoliquiritigenin (ISL), a member of the flavonoids, has been demonstrated to possess antitumor activity in various cancer cell lines in vitro and in vivo. In this study, we investigated the antitumor effects of ISL on U87 glioma cells in vitro. As determined by MTT assay, ISL inhibited the proliferation of U87 cells in a time-dependent and dose-dependent manner. The results of fluorescence-activated cell sorting (FACS) analysis suggested that ISL induced the apoptosis of the U87 cells and blocked cell cycle progression at the S and G2/M phases. Moreover, it was identified that ISL induced the apoptosis of the U87 cells in a caspase-dependent manner. Although treatment with the pan-caspase inhibitor Z-VAD-FMK efficiently blocked the ISL-induced caspase activation, it did not eliminate the ISL-induced cell death. Further examination using western blot analysis revealed that ISL upregulated p21/WAF1 and p27. These results indicate that cell cycle arrest and the caspase-mediated apoptosis pathway may participate in the antiproliferative activity of ISL in U87 cells by regulating the expression of specific molecules.