wogonin and Colorectal-Neoplasms

Wogonin, a naturally occurring mono-flavonoid, has been reported to have tumor therapeutic potential and good selectivity both in vitro and in vivo. Herein, we investigated the anti-proliferation effects and associated mechanisms of wogonin in human colorectal cancer in vitro. The flow-cytometric analysis showed that wogonin induced a G1 phase cell cycle arrest in HCT116 cells in a concentration- and time-dependent manner. Meanwhile, the cell cycle-related proteins, such as cyclin A, E, D1, and CDK2, 4 were down-regulated in wogonin-induced G1 cell cycle arrest. Furthermore, we showed that the anti-proliferation and G1 arrest effect of wogonin on HCT116 cells was associated with deregulation of Wnt/β-catenin signaling pathway. Wogonin-treated cells showed decreased intracellular levels of Wnt proteins, and activated degradation complex to phosphorylated and targeted β-catenin for proteasomal degradation. Wogonin inhibited β-catenin-mediated transcription by interfering in the transcriptional activity of TCF/Lef, and repressing the kinase activity of CDK8 which has been considered as an oncogene involving in the development of colorectal cancers. Moreover, CDK8 siRNA-transfected HCT116 cells showed similar results to wogonin treated cells. Thus, our data suggested that wogonin induced anti-proliferation and G1 arrest via Wnt/β-catenin signaling pathway and it can be developed as a therapeutic agent against human colorectal cancer.

Topics: Cell Survival; Colorectal Neoplasms; Cyclin-Dependent Kinase 8; Drugs, Chinese Herbal; Flavanones; G1 Phase Cell Cycle Checkpoints; HCT116 Cells; Humans; Lymphoid Enhancer-Binding Factor 1; Wnt Signaling Pathway; Xenograft Model Antitumor Assays

Topics: Adenocarcinoma; Antineoplastic Agents; Apoptosis; Cell Culture Techniques; Cell Line, Tumor; Cell Proliferation; Cell Survival; Colorectal Neoplasms; Curcumin; Drug Screening Assays, Antitumor; Flavanones; Humans; Lab-On-A-Chip Devices; Microfluidic Analytical Techniques; Microfluidics; Neoplasms; Polyphenols; Resveratrol; Tumor Microenvironment

Wogonin is a main effective component of Scutellaria baicalensis, with a significant anti-cancer activity. Recently, extensive studies focused on anti-cancer pharmacological effects of wogonin, but there were still a few studies on its molecular mechanism. Therefore, the molecular targets of its anti-cancer activity were still unclear. In this study, network pharmacology was applied to investigate the potential targets and molecular pathway of wogonin in inhibiting the growth of colorectal cancer. It indicated that Wnt/β-catenin was a key pathway of wogonin on colorectal cancer. Then, pharmacology and molecular mechanism studies were performed according to network pharmacological results. Pharmacological results revealed that wogonin inhibited significantly the proliferation of SW480(P<0.001), with a concentration-dependent regularity in the range of 12.5-50 μmol·L~(-1). Additionally, wogonin could induce G_1 phase blocking of SW480 cells. Western blot was used to investigate the effect of wogonin on four characteristic proteins of Wnt/β-catenin pathway. CTNNB1(β-catenin), BIRC5(survivin) and GSK3 B were down-regulated significantly, while the expression level of BAX was up-regulated(P<0.05). In conclusion, wogonin could inhibit the proliferation of SW480 cells through Wnt/β-catenin pathway. The feature protein CTNNB1(β-catenin), BIRC5(survivin), GSK3 B and BAX were identified as the potential targets. This study illuminated the anti-cancer molecular mechanism and drug targets of wogonin, which provided a theoretical basis for anti-colon cancer drug discovery and clinical application.

Topics: beta Catenin; Cell Line, Tumor; Cell Proliferation; Colorectal Neoplasms; Flavanones; Glycogen Synthase Kinase 3; Humans; Wnt Signaling Pathway

Individuals with ulcerative colitis (UC) are at a high risk for developing colorectal cancer (CRC). Huangqin Decoction (HQD), a traditional Chinese medicinal formula chronicled in the Shang Han Lun, is commonly used to treat gastrointestinal symptoms. However, experimental evidence for supporting the clinical practice is lacking. This study used modern biomedical approaches to investigate the protective/preventive effects of HQD in dextran sulfate sodium (DSS)-induced acute/chronic UC and azoxymethane (AOM)/DSS-induced CRC in mice. HQDs were prepared in 4 different ways: HQD-1 and HQD-2 were prepared in boiling water, whereas HQD-3 and HQD-4 were prepared in heated ethanol (70%). For HQD-1 and HQD-3, the 4 constituent herbs were processed together, whereas for HQD-2 and HQD4, these herbs were processed individually and then combined. The mice were administered 9.1 g/kg HQD via oral gavage daily. HQD-1 significantly inhibited DSS-induced acute UC, whereas HQD-3 and HQD-4 exhibited mild ameliorative effects; but HQD-2 had no protective effect and resulted in a higher mortality rate. This higher mortality rate may be due to the greater abundance of baicalein and wogonin in HQD-2 than HQD-1. Furthermore, HQD-1 protected against DSS-induced chronic UC and significantly inhibited AOM/DSS-induced CRC in mice. HQD-1 also inhibited the production of inflammatory cytokines and increased antioxidant capacity both in chronic DSS and AOM/DSS treated mice. Overall, HQD-1 inhibits the development of acute/chronic colitis and prevents colitis-associated CRC, possibly by inhibiting inflammation and preventing oxidative stress induced cellular damage.

Topics: Animals; Antioxidants; Azoxymethane; Chromatography, High Pressure Liquid; Colitis, Ulcerative; Colorectal Neoplasms; Cytokines; Dextran Sulfate; Disease Models, Animal; Drugs, Chinese Herbal; Flavanones; Inflammation; Male; Medicine, Chinese Traditional; Mice; Mice, Inbred C57BL; Neoplasms, Experimental; Oxidative Stress; Plant Extracts; Scutellaria baicalensis

The transcriptional factors nuclear factor-κB (NF-κB) and NF-E2-related factor 2 (Nrf2) have been recently reported to have critical roles in protecting various tissues against inflammation and colitis-associated colorectal cancer (aberrant crypt foci). Our previous studies showed that wogonin (5,7-dihydroxy-8-methoxyflavone) possessed anti-neoplastic and anti-inflammatory activities. The present study extended these important earlier findings by exploring the effect of wogonin on the initiation and development of colitis-associated cancer. Wogonin lowered tumor incidence and inhibited the development of colorectal adenomas in azoxymethane- or dextran sulfate sodium-induced mice. We found that wogonin significantly decreased the secretion and expression of IL-6 and IL-1β, reduced cell proliferation and nuclear expression of NF-κB in adenomas and surrounding tissues and promoted Nrf2 nuclear translocation in surrounding tissues, although overexpressed Nrf2 in tumor tissues was independent of wogonin administration. Furthermore, wogonin inhibited the interaction between human monocytic THP-1 cells and human colon cancer HCT116 cells, and significantly downregulated lipopolysaccharide-induced secretion of prototypical pro-inflammatory cytokines IL-6 and IL-1β in THP-1 cells. Further mechanism research revealed that wogonin inhibited the nuclear translocation of NF-κB and phosphorylation of IκB and IKKα/β, and promoted Nrf2 signaling pathway in HCT116 cells and THP-1 cells. Taken together, the present results indicated that wogonin effectively suppressed inflammation-associated colon carcinogenesis and cancer development, suggesting its potential as a chemopreventive agent against colitis-associated colon cancer.

Topics: Active Transport, Cell Nucleus; Animals; Cell Line, Tumor; Cell Nucleus; Colorectal Neoplasms; Flavanones; Humans; Interleukin-1beta; Interleukin-6; Mice; Neoplasm Proteins; NF-E2-Related Factor 2; NF-kappa B; Signal Transduction

Scutellaria baicalensis extract (SbE) has been shown to exert chemopreventive effects on several types of cancer. Baicalin, a hydrophilic flavonoid found in SbE, may have opposing effects that decrease the antitumor potential of SbE against colorectal cancer. In this study, after removing baicalin, we prepared an aglycone-rich fraction (ARF) of SbE and evaluated its anti-proliferative activity and mechanisms of action. The flavonoids found in ARF, baicalin fraction (BF) and SbE were determined by high-performance liquid chromatography (HPLC). The effects of ARF, BF, SbE and representative flavonoids on the proliferation of HCT-116 and HT-29 human colorectal cancer cells were determined by an MTS assay. The cell cycle, the expression of cyclins A and B1 and cell apoptosis were assayed using flow cytometry. Apoptosis-related gene expression was visualized by quantitative real-time polymerase chain reaction (PCR), and mitochondrial membrane potential was estimated following staining with JC-1. HPLC analysis showed that ARF contained two hydrophobic flavonoids, baicalein and wogonin, and that BF contained only baicalin. SbE had little anti-proliferative effect on the colorectal cancer cells; cancer cell growth was even observed at certain concentrations. ARF exerted potent anti-proliferative effects on the cancer cells. By contrast, BF increased cancer cell growth. ARF arrested cells in the S and G2/M phases, increased the expression of cyclins A and B1, and significantly induced cell apoptosis. Multiple genes in the mitochondrial pathway are involved in ARF-induced apoptosis, and subsequent cellular functional analysis validated the involvement of this pathway. These results suggest that removing baicalin from SbE produces an ARF that significantly inhibits the growth of colorectal cancer cells, and that the mitochondrial apoptotic pathway plays a role in hydrophobic flavonoid-induced apoptosis.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Cell Line, Tumor; Cell Proliferation; Chemoprevention; Colorectal Neoplasms; Cyclin A; Cyclin B1; Enzyme Inhibitors; Flavanones; Flavonoids; G2 Phase Cell Cycle Checkpoints; Gene Expression; Humans; Iridoids; Membrane Potential, Mitochondrial; Mitochondria; Phytotherapy; Plant Extracts; S Phase Cell Cycle Checkpoints; Scutellaria baicalensis

The purpose of this study was to determine the effects of baicalein and wogonin, which are compounds derived from the Chinese herb Scutellaria baicalensis, in suppressing the viability of HT-29 human colon cancer cells. Following treatment with baicalein or wogonin, several apoptotic events were observed, including DNA fragmentation, chromatin condensation and increased cell cycle arrest in the G1 phase. Baicalein and wogonin decreased Bcl-2 expression, whereas the expression of Bax was increased in a dose-dependent manner compared with the control. Furthermore, the induction of apoptosis was accompanied by an inactivation of phosphatidylinositol 3-kinase (PI3K)/Akt in a dose-dependent manner. The administration of baicalein to mice resulted in the inhibition of the growth of HT-29 xenografts without any toxicity following 5 weeks of treatment. The results indicated that baicalein induced apoptosis via Akt activation in a p53-dependent manner in the HT-29 colon cancer cells and that it may serve as a chemopreventive or therapeutic agent for HT-29 colon cancer.

Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; bcl-2-Associated X Protein; Colorectal Neoplasms; DNA Damage; Flavanones; G1 Phase Cell Cycle Checkpoints; HT29 Cells; Humans; Male; Mice; Mice, Nude; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-bcl-2; Scutellaria; Transplantation, Heterologous