Exploring the anti-atherosclerosis mechanism of ginsenoside Rb1 by integrating network pharmacology and experimental verification.

Ginsenoside Rb1 is the major active constituent of ginseng, which is widely used in traditional Chinese medicine for the atherosclerosis treatment by anti-inflammatory, anti-oxidant and reducing lipid accumulation. We explored cellular target and molecular mechanisms of ginsenoside Rb1 based on network pharmacology and in vitro experimental validation. In this study, we predicted 17 potential therapeutic targets for ginsenoside Rb1 with atherosclerosis from public databases. We then used protein-protein interaction network to screen the hub targets. Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway enrichment showed that the effects of ginsenoside Rb1 were meditated through multiple targets and pathways. Next, molecular docking results revealed that in the 10 core targets, CCND1 has the highest binding energy with ginsenoside Rb1. Vascular cell proliferation plays a critical role in atherosclerosis development. However, the effect and direct target of ginsenoside Rb1 in regulating vascular cell proliferation in atherosclerosis remains unclear. Edu straining results indicated that ginsenoside Rb1 inhibited the cell proliferation of endothelial cells, macrophages, and vascular smooth muscle cells. The protein immunoprecipitation (IP) analysis showed that ginsenoside Rb1 inhibited the vascular cell proliferation by suppressing the interaction of CCDN1 and CDK4. These findings systematically reveal that the anti-atherosclerosis mechanism of ginsenoside Rb1 by integrating network pharmacology and experimental validation, which provide evidence to treat atherosclerosis by using ginsenoside Rb1 and targeting CCND1.

Say 'No' to Cancer and 'Yes' to Cranberry: The Role of Cranberry Extract in Inhibition of Growth of Lung Adenocarcinoma Cells.

BACKGROUND/AIM: Lung cancer is the leading cause of mortality due to cancer death. Treatment of lung adenocarcinoma (LUAD) is still challenging. Cranberries contain many rich bioactive components that may help fight cancer. The action of cranberry against some cancer types has been reported, however, its role in lung cancer has only been investigated in large-cell lung cancer. In this study, we expanded current research on the role of cranberry in LUAD. MATERIALS AND METHODS: A549 LUAD cancer cells were treated with commercial cranberry extract (CE). Proliferation of A549 cells was measured with a clonogenic survival assay and quick proliferation assay. Caspase-3 activity was used to evaluate apoptosis of A549 cells. Reverse transcriptase-polymerase chain reaction was conducted to investigate the possible molecular mechanisms involved in the action of CE. RESULTS: Treatment of LUAD with CE reduced the percentage of A549 colonies. This was consistent with the decrease in the optic density of cancer cells after treatment with CE. Caspase-3 activity increased after treatment with CE. The anti-proliferative effect of CE on A549 cells correlated with reduced expression of pro-proliferation molecules cyclin E, cyclin-dependent kinase 2 (CDK2) and CDK4. The pro-apoptotic effect of CE on A549 cells correlated with the reduced expression of the anti-apoptotic molecule caspase 8 and FADD-like apoptosis regulator (FLIP). CONCLUSION: CE had an inhibitory effect on the growth of LUAD cells by modulation of both pro-proliferative and anti-apoptotic molecules. Our research hopes to guide future treatment options for LUAD.

Potential use of kiwifruit extract for treatment of melanoma.

Skin cancers are the most common cancers in the world and among the different types of skin cancers, melanoma is the deadliest and incidence is rising. Previous studies have shown promising in vitro and human evidence of kiwifruit exhibiting anti-cancer effects. This study was designed to investigate if kiwifruit extract (KE) has any effect on CRL-11147 melanoma cancer cells and to investigate the possible mechanisms behind the results. The effects of KE on CRL-11147 melanoma cell survival, proliferation, and apoptosis was investigated using clonogenic survival assay, cell proliferation, and caspase-3 activity kits. Potential anti-tumor molecular mechanisms were elucidated using RT-PCR and IHC. Addition of KE decreased CRL-11147 cell colonies percentages indicated by a decreased optical density value of cancer cells when compared to control. Furthermore, treatment with KE increased relative caspase-3 activity in cancer cells, which indicated increased apoptosis of cancer cells. The anti-proliferative effect of KE on cancer cells corresponded with decreased expression of the pro-proliferative molecule Cyclin E and CDK4, while increased expression of the pro-apoptotic molecule TRAILR1 corresponded with the pro-apoptotic effect. KE decreases CRL-11147 melanoma cell growth via downregulation of Cyclin E and CDK4 and upregulation in TRAILR1. Our study suggests a potential use for KE in treatment of melanoma.

15-Hydroxy-8(17),13(E)-labdadiene-19-carboxylic acid (HLCA) inhibits proliferation and induces cell cycle arrest and apoptosis in ovarian cancer cells.

AIM: 15-Hydroxy-8(17),13(E)-labdadiene-19-carboxylic acid (HLCA) isolated from Juniperus foetidissima, has been recently identified as an antiproliferative agent; however, the molecular basis of antiproliferative effects of HLCA remains unknown. To investigate it, the current study has emphasized the hypothesis that HLCA induced cell death is a consequence of intracellular reactive oxygen species (ROS) production followed by cell cycle arrest and apoptosis. MAIN METHODS: Human ovarian OVCAR-3 and Caov-4 cells were treated with various concentrations of HLCA (48 h) and the measurement of intracellular ROS was considered. Then, the potential of HLCA in promoting apoptosis was investigated via flow cytometry, western blot, and caspase activity assay. Also, the inhibitory effect of HLCA on the cell cycle was evaluated using flow cytometry and western blot analysis. KEY FINDINGS: We found intracellular (ROS) accumulation in HLCA-treated cells. Subsequent observation of the increment in pro-apoptotic Bax as well as the decrement in antiapoptotic Bcl2 revealed that the HLCA-induced cytotoxicity may be triggered by the intrinsic pathway of apoptosis. Our subsequent experiments suggested that caspase-9 and -3 were activated and led the cells to apoptosis during the process. Cell cycle disruption at the G1 phase via down-regulation of cyclin D1 and Cyclin-dependent kinase 4 (CDK4) was another proved mechanism by which HLCA exerts its antiproliferative effects on the ovarian cell lines, OVCAR-3 and Caov-4, especially at relatively lower concentrations. SIGNIFICANCE: This is the first study that reveals the apoptotic effects of HLCA, suggesting its therapeutic potential as an effective anti-tumor agent. However, further in vivo studies are required to confirm these effects.

Comparison of phenolics, antioxidant, and antiproliferative activities of two Hypsizygus marmoreus varieties.

Phenolics, antioxidant activities, and antiproliferative properties of brown Hypsizygus marmoreus (brown HM) and white Hypsizygus marmoreus (white HM) were compared. The results showed that the contents of (+)-catechin, gallic acid, and protocatechuic acid of brown HM were higher than those of white HM. Moreover, brown HM had greater cellular antioxidant activity (CAA), peroxyl radical scavenging capacity (PSC), and oxygen radical absorbance capacity (ORAC) values than white HM, which demonstrated that brown HM presented a stronger antioxidant capacity. Both of brown HM and white HM showed remarkable antiproliferative activities against HepG2 cells and brown HM was proven to be the more effective. The flow cytometry results revealed that both of brown HM and white HM could induce G1 arrest and cell apoptotics in a dose-dependent manner. In addition, CyclinD1, CDK4, and Bcl-2 mRNA expression levels were downregulated with the treatment of brown HM or white HM. Taken together, our study revealed that brown HM afforded better antioxidant and antiproliferative activities than white HM and laid the foundation for potential application of Hypsizygus marmoreus as source of nutraceuticals and functional food products. PRACTICAL APPLICATION: A systematic assessment of the potential differences of phenolics, antioxidant, and antiproliferative activities between different Hypsizygus marmoreus varieties was carried out in the present study. Furthermore, our findings would present possible antiproliferative mechanism of extracts of different Hypsizygus marmoreus varieties, which may provide theoretical basis for further development and utilization of Hypsizygus marmoreus.

Effect of Angelica gigas Nakai Ethanol Extract and Decursin on Human Pancreatic Cancer Cells.

Pancreatic cancer (PC) is one of the most severe cancers, and its incidence and mortality rates have steadily increased in the past decade. In this study, we demonstrate the effect of Angelica gigas Nakai extract on pancreatic ductal adenocarcinoma cells. We prepared A. gigas Nakai ethanol extract (AGE) using roots of A. gigas Nakai and detected its active compound decursin from AGE by ultra-performance liquid chromatography analysis. AGE and decursin significantly decreased viability and colony formation of PANC-1 and MIA PaCa-2 cells. AGE and decursin induced G0/G1 phase arrest through downregulation of cyclin D1 and cyclin-dependent kinase 4 (CDK4). Caspase-3-dependent apoptosis of PANC-1 cells was promoted by AGE and decursin. Additionally, nontoxic concentrations of AGE and decursin treatment could suppress matrix metalloproteinase (MMP)-2 and MMP-9 expression and activity by inhibiting p38 phosphorylation. Taken together, this study demonstrates that AGE and decursin have potential properties to be considered in PC treatment.

Discovery of novel and selective CDK4/6 inhibitors by pharmacophore and structure-based virtual screening.

Aim: CDK4 and 6 are the key initiators in the transition from G1 to S phase in the cell cycle; thus, inhibition of CDK4/6 is a promising strategy for cancer treatment. Materials & methods: The Specs database and an in-house library were screened via the pharmacophore model and LibDock protocol and then the retrieved hits were clustered into 100 clusters. The CDK4/6 inhibitory activity of selected compounds was evaluated by CDK enzymatic assays, followed by chemical optimization of the top hit compound. Results & conclusion: The integration of pharmacophores and molecular docking offered us an effective method to discover the novel CDK4/6 inhibitor 10 and further chemical optimization led to the highly selective and potent CDK4/6 inhibitor 18, which exhibited potential for the treatment of multiple myeloma.

Curcumin Nanoemulsions Stabilized with Modified Phosphatidylcholine on Skin Carcinogenesis Protocol.

BACKGROUND: Cancer is one of the main causes of death by disease; several alternative treatments have been developed to counteract this condition. Curcumin (diferuloylmethane), extracted from the rhizome of Curcuma longa, has antioxidant, anti-inflammatory, and anti-cancer properties; however, it has low water solubility and poor intestinal absorption. Carrier systems, such as nanoemulsions, can increase the bioavailability of lipophilic bioactive compounds. OBJECTIVE: To evaluate the effect of curcumin nanoemulsions prepared with lecithin modified with medium-chain fatty acids as an emulsifier, on the expression of the Cdk4, Ccne2, Casp8 and Cldn4 genes involved in the carcinogenesis process in K14E6 transgenic mice. METHODS: The emulsifier was prepared by interesterification of medium-chain fatty acids, pure lecithin, and immobilized phospholipase-1 on Duolite A568. An Ultraturrax homogenizer and a Branson Ultrasonic processor were used for the preparation of nano-emulsions, and a Zetasizer evaluated the particle size. qRT-PCR analysis was performed to quantify the cancer-related genes expressed in the K14E6 mice. The development and evolution of skin carcinogenesis were assessed through histological analysis to compare cell morphology. RESULTS: Ca 59% of the MCFA were incorporated via esterification into the PC within 12 hours of the reaction. An emulsifier yield used to formulate the NE of 86% was achieved. Nanoemulsions with a particle size of 44 nm were obtained. The curcumin nano-emulsion group had a 91.81% decrease in the tumorigenesis index and a reduction in tumor area of 89.95% compared to the sick group. Histological analysis showed that the group administered with free curcumin developed a microinvasive squamous cell carcinoma, as opposed to the group with nanoemulsion which presented only a slight inflammation. In gene expression, only a significant difference in Cdk4 was observed in the nanoemulsion group.

Huganpian, a traditional chinese medicine, inhibits liver cancer growth in vitro and in vivo by inducing autophagy and cell cycle arrest.

Huganpian (HGP), a traditional chinese medicine composed of 6 herbs, possesses excellent therapeutic effects in clinical application. In this study, we aimed to elucidate the anti-tumor activity and the underlying mechanisms of HGP in liver cancer. The results of this study indicated that HGP effectively inhibited liver cancer growth in vitro and in vivo in a dose-dependent manner. Mechanistically, HGP exerted its anti-tumor effects by triggering autophagy with increased LC3Ⅱ and beclin1 levels and arrested the cell cycle on G0-G1 phase by downregulating the expressions of cyclin-dependent kinase 2 (CDK2), cyclin-dependent kinase 4 (CDK4) and cyclinE1 in vitro and in vivo. Meanwhile, HGP did not induce apoptosis significantly. Importantly, we also confirmed that there were fewer side effects of HGP on immune system. Taken together, our findings suggest for the first time that HGP may become a promising drug or adjuvant drug with a lower toxicity for liver cancer treatment in the future.

Centaurea cyanus extracted 13-O-acetylsolstitialin A decrease Bax/Bcl-2 ratio and expression of cyclin D1/Cdk-4 to induce apoptosis and cell cycle arrest in MCF-7 and MDA-MB-231 breast cancer cell lines.

Natural products are considered recently as one of the source for production of efficient therapeutical agents for breast cancer treatment. In this study, a sesquiterpene lactone, 13-O-acetylsolstitialin A (13ASA), isolated from Centaurea cyanus, showed cytotoxic activities against MCF-7 and MDA-MB-231 breast cancer cell lines using standard 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. To find the mechanism of action of cytotoxicity, annexin V/propidium iodide (PI) staining was performed for evaluation of apoptosis. This process was further confirmed by immunoblotting of anti- and proapoptotic, Bcl-2 and Bax, proteins. Cell cycle arrest was evaluated by measurement of fluorescence intensity of PI dye and further confirmed by immunoblotting of Cdk-4 and cyclin D1. Mitochondrial transmembrane potential (ΔΨm) and generation of reactive oxygen species (ROS) were measured using the JC-1 and DCFDA fluorescence probes, respectively. These experiments showed that 13ASA is a potent cytotoxic agent, which activates apoptosis-mediated cell death. In response to this compound, Bax/Bcl-2 ratio was noticeably increased in MCF-7 and MDA-MB-231 cells. Moreover, 13ASA induced cell cycle arrest at subG1 and G1 phases by decreasing protein levels of cyclin D1 and Cdk-4. It was done possibly through the decrease of ΔΨm and increase of ROS levels which induce apoptosis. In conclusion, this study mentioned that 13ASA inhibit the growth of MCF-7 and MDA-MB-231 breast cancer cell lines through the induction of cell cycle arrest, which triggers apoptotic pathways. 13ASA can be considered as a susceptible compound for further investigation in breast cancer study.

Brucea javanica oil emulsion improves the effect of radiotherapy on esophageal cancer cells by inhibiting cyclin D1-CDK4/6 axis.

BACKGROUND: Esophageal cancer is one of the most common cancers around the world, and it has high incidence and mortality rates. The conventional therapy for esophageal cancer is radiotherapy, although its effect is highly limited by the resistance of esophageal cancer cells. Thus, strong radiosensitizers can be very crucial during radiotherapy against esophageal cancer. Brucea javanica oil emulsion (BJOE) is a widely used drug against various cancers, such as liver, colon, and ovarian cancer. However, its anti-cancer effect and mechanism and the use of BJOE as a radiosensitizer have not been explored in esophageal cancer. AIM: To evaluate the anti-cancer effect and mechanism of BJOE and explore the potential use of BJOE as a radiosensitizer during radiotherapy. METHODS: The inhibitory effect of BJOE and its enhancement function with radiation on cell viability were examined with the calculated half-maximal effective concentration and half-maximal lethal concentration. The influence of BJOE on cell migration and invasion were measured with EC109 and JAR cells by wound-healing and transwell assay. Clonogenesis and apoptotic rate, which was measured by Hoechst staining, were investigated to confirm its enhancement function with radiation. To investigate the molecular pathway underlying the effect of BJOE, the expressions of several apoptosis- and cycle-related proteins was detected by western blotting. RESULTS: Our results demonstrated that BJOE inhibited the growth of esophageal cancer cell lines more than normal cell lines, and it markedly reduced migration and invasion in esophageal cancer cells (EC109 and JAR). Moreover, it promoted cell apoptosis and enhanced the effect of radiotherapy against esophageal cancerous cells. In the viability test, the values of half-maximal effective concentration and half-maximal lethal concentration were reduced. Compared to the control, only around 1/5 colonies formed when using BJOE and radiation together in the clonogenic assay. The apoptotic rate in EC109 was obviously promoted when BJOE was added during radiotherapy. Our study suggests that the expression of the apoptosis-proteins Bax and p21 were increased, while the expression of Bcl-2 was stable. Further detection of downstream proteins revealed that the expression of cyclin D1 and cyclin-dependent kinase 4/6 were significantly decreased. CONCLUSION: BJOE has a strong anti-cancer effect on esophageal cancer and can be used as a radiosensitizer to promote apoptosis in cancerous esophageal cells via the cyclin D1-cyclin-dependent kinase 4/6 axis.

ß-Thujaplicin inhibits basal-like mammary tumor growth by regulating glycogen synthase kinase-3ß/ß-catenin signaling.

ß-Thujaplicin, a natural monoterpenoid, has been demonstrated to exert health beneficial activities in chronic diseases. However, it has not been studied in regulating estrogen receptor (ER) negative breast cancer. Here, we investigated the effect of ß-thujaplicin on inhibiting ER-negative basal-like breast cancer and the underlying mechanism of action using an in vitro and in vivo xenograft animal model. ß-Thujaplicin induced G0/G1 phase cell cycle arrest and regulated cell cycle mediators, cyclin D1, cyclin E, and cyclin-dependent kinase 4 (CDK 4), leading to the inhibition of the proliferation of ER-negative basal-like MCF10DCIS.com human breast cancer cells. It also modulated the phosphorylation of protein kinase B (AKT) and glycogen synthase kinase (GSK-3ß) and the protein level of ß-catenin. In an MCF10DCIS.com xenograft animal model, ß-thujaplicin significantly inhibited tumor growth, reduced tumor weight, and regulated the expression of cell cycle proteins, phosphorylation of AKT and GSK-3ß, and protein level of ß-catenin in the tumor tissues. These results demonstrate that ß-thujaplicin can suppress basal-like mammary tumor growth by regulating GSK-3ß/ß-catenin signaling, suggesting that ß-thujaplicin may be a potent chemopreventive agent against the basal-like subtype of breast cancer.

Preclinical characterization of SHR6390, a novel CDK 4/6 inhibitor, in vitro and in human tumor xenograft models.

Inhibition of the cyclin-dependent kinase (CDK) 4/6-retinoblastoma (RB) pathway is an effective therapeutic strategy against cancer. Here, we performed a preclinical investigation of the antitumor activity of SHR6390, a novel CDK4/6 inhibitor. SHR6390 exhibited potent antiproliferative activity against a wide range of human RB-positive tumor cells in vitro, and exclusively induced G1 arrest as well as cellular senescence, with a concomitant reduction in the levels of Ser780-phosphorylated RB protein. Compared with the well-known CDK4/6 inhibitor palbociclib, orally administered SHR6390 led to equivalent or improved tumor efficacy against a panel of carcinoma xenografts, and produced marked tumor regression in some models, in association with sustained target inhibition in tumor tissues. Furthermore, SHR6390 overcame resistance to endocrine therapy and HER2-targeting antibody in ER-positive and HER2-positive breast cancer, respectively. Moreover, SHR6390 combined with endocrine therapy exerted remarkable synergistic antitumor activity in ER-positive breast cancer. Taken together, our findings indicate that SHR6390 is a novel CDK4/6 inhibitor with favorable pharmaceutical properties for use as an anticancer agent.

Lipophilic Grape Seed Proanthocyanidin Exerts Anti-Proliferative and Pro-Apoptotic Effects on PC3 Human Prostate Cancer Cells and Suppresses PC3 Xenograft Tumor Growth in Vivo.

The in vitro antiprostate cancer activity of lipophilic grape seed proanthocyanidin (LGSP) against the PC3 cell line was evaluated by MTT assay, flow cytometry, and immunoblot analysis, and the in vivo antiprostate cancer effect was evaluated by a PC3-derived mouse xenograft model via oral gavage LGSP. Ki67 and cleaved caspase 3 immunostaining experiments were performed in tumor tissues. LGSP exhibited a strong inhibitory effect on PC3 cell proliferation by inducing apoptosis. Treatment with LGSP resulted in a G1 phase cell cycle arrest in PC3 cells, which was further confirmed by decreasing the expression of cyclin D1 and CDK 4 and increasing the expression of the tumor suppressors p21 and p27. Furthermore, activation of cleaved fragments of caspases 3, caspases 9, and PARP indicated that LGSP-induced apoptosis is caspase-dependent. Upstream of caspase cascade, LGSP increased the cytochrome c release in cytoplasm. After treatment with LGSP, the Bcl-2/Bax ratio also decreased in PC3 cells. In tumor studies, LGSP inhibited the growth of PC3-derived mouse xenografts by inhibiting tumor cell proliferation and inducing apoptosis. Our findings suggest that LGSP is an effective antiprostate cancer component and deserves further study.

Cyclin-dependent kinase 4 is a preclinical target for diet-induced obesity.

When obesity is caused by consumption of a high-fat diet, the tumor suppressor pRb is phosphoinactivated in the neurons of the mediobasal hypothalamus, a brain area critical for energy-balance regulation. However, the functional relevance of pRb phosphoinactivation in the mediobasal hypothalamus to diet-induced obesity remains unknown. Here, we show that inhibiting pRb phosphorylation in the mediobasal hypothalamus can prevent and treat diet-induced obesity in mice. Expressing an unphosphorylable pRb nonselectively in the mediobasal hypothalamus or conditionally in anorexigenic POMC neurons inhibits diet-induced obesity. Intracerebroventricular delivery of US Food and Drug Administration-approved (FDA-approved) cyclin-dependent kinase 4 (CDK4) inhibitor abemaciclib inhibits pRb phosphorylation in the mediobasal hypothalamus and prevents diet-induced obesity. Oral administration of abemaciclib at doses approved for human use reduces fat mass in diet-induced obese mice by increasing lipid oxidation without significantly reducing lean mass. With analysis of recent literature identifying CDK4 as the most abundantly expressed neuronal CDK in the mediobasal hypothalamus, our work uncovers CDK4 as the major kinase for hypothalamic pRb phosphoinactivation and a highly effective central antiobesity target. As three CDK4/6 inhibitors have recently received FDA approval for life-long breast cancer therapy, our study provides a preclinical basis for their expedient repurposing for obesity management.

Guanidinoacetic Acid Regulates Myogenic Differentiation and Muscle Growth Through miR-133a-3p and miR-1a-3p Co-mediated Akt/mTOR/S6K Signaling Pathway.

Guanidinoacetic acid (GAA), an amino acid derivative that is endogenous to animal tissues including muscle and nerve, has been reported to enhance muscular performance. MicroRNA (miRNA) is a post-transcriptional regulator that plays a key role in nutrient-mediated myogenesis. However, the effects of GAA on myogenic differentiation and skeletal muscle growth, and the potential regulatory mechanisms of miRNA in these processes have not been elucidated. In this study, we investigated the effects of GAA on proliferation, differentiation, and growth in C2C12 cells and mice. The results showed that GAA markedly inhibited the proliferation of myoblasts, along with the down-regulation of cyclin D1 (CCND1) and cyclin dependent kinase 4 (CDK4) mRNA expression, and the upregulation of cyclin dependent kinase inhibitor 1A (P21) mRNA expression. We also demonstrated that GAA treatment stimulated myogenic differentiation 1 (MyoD) and myogenin (MyoG) mRNA expression, resulting in an increase in the myotube fusion rate. Meanwhile, GAA supplementation promoted myotube growth through increase in total myosin heavy chain (MyHC) protein level, myotubes thickness and gastrocnemius muscle cross-sectional area. Furthermore, small RNA sequencing revealed that a total of eight miRNAs, including miR-133a-3p and miR-1a-3p cluster, showed differential expression after GAA supplementation. To further study the function of miR-133a-3p and miR-1a-3p in GAA-induced skeletal muscle growth, we transfected miR-133a-3p and miR-1a-3p mimics into myotube, which also induced muscle growth. Through bioinformatics and a dual-luciferase reporter system, the target genes of miR-133a-3p and miR-1a-3p were determined. These two miRNAs were shown to modulate the Akt/mTOR/S6K signaling pathway by restraining target gene expression. Taken together, these findings suggest that GAA supplementation can promote myoblast differentiation and skeletal muscle growth through miR-133a-3p- and miR-1a-3p-induced activation of the AKT/mTOR/S6K signaling pathway.

Schisantherin A Improves Learning and Memory of Mice with D-Galactose-Induced Learning and Memory Impairment Through Its Antioxidation and Regulation of p19/p53/p21/Cyclin D1/CDK4/RB Gene Expressions.

Schisantherin A (SCA) was evaluated for possible function in restoring the learning and memory impairment induced by D-galactose in mice. ICR mice were treated with D-galactose subcutaneously (220 mg·kg-1), and followed by SCA in different doses (1.25, 2.50 and 5.00 mg·kg-1, administered orally) for 42 days. Effects of SCA on learning and memory were examined by step-through tests and Morris water maze tests. The activity of superoxide dismutase (SOD), the content of malondialdehyde (MDA) in the peripheral blood and hippocampus of mice were assayed by water-soluble tetrazolium-1 (WST-1) and thiobarbituric acid (TBA) methods. The contents of 8 hydroxy deoxy guanosine (8-OHdG) in the hippocampus of mice were detected by immunosorbent assay methods, respectively. Quantitative real-time PCR and Western Blot were respectively used to detect the expression of p19, p53, p21, cyclin D1, CDK4 and RB genes, and the phosphorylation of RB in the hippocampus of mice. We found that SCA significantly improved the learning and memory impairment induced by D-galactose in mice. After SCA treatment, SOD activity was increased and the content of MDA was decreased in both peripheral blood and hippocampus of mice. 8-OHDG content was also decreased in the hippocampus of mice. Furthermore, the expression of p19, p53 and p21 genes was reduced and the expression of cyclin D1 and CDK4 and the phosphorylation of RB protein were elevated in the hippocampus. SCA may improve the learning and memory impairment induced by D-galactose by enhancing the antioxidant capacity, and regulating the expression of p19/p53/p21/cyclinD1/CDK4 genes, and the phosphorylation of RB protein in the hippocampus of mice.

[Artesunate inhibits proliferation of glioblastoma cells by arresting cell cycle].

Glioblastoma is a common brain tumor and the overall survival rate of the patients is very low, so it is an effective way to develop the potential chemotherapy or adjuvant chemotherapy drugs in glioblastoma treatment. As a well-known antimalarial drug, artesunate(ARTs) has clear side effects, and recently it has been reported to have antitumor effects, but rarely reported in glioblastoma. Different concentrations of ARTs were used to treat the glioblastoma cells, and then the inhibitory effect of ARTs on glioblastoma proliferation was detected by MTT assay; Ki67 immunofluorescence assay was used to detect the proliferation of cells; Soft agar experiment was used to explain the clonal formation abilities in vitro; Flow Cytometry was used to detect the cell cycle; and Western blot assay was used to determine the expression of key cell cycle protein. MTT assay results indicated that ARTs-treated glioblastoma cell A172, U251, U87 were significantly inhibited in a time-and-dose dependent manner as compared to the control group(DMSO treatment group). Soft agar experiment showed that ARTs could significantly reduce the clonal formation ability of glioblastoma. Furthermore, Flow cytometry analysis showed that ARTs could obviously increase the cell proportion in G0/G1 phase and reduce the cell proportion in S phase. Western blot results showed that the expressions of cell cycle-related proteins CDK2, CDK4, cyclin D1 and cyclin B1 were all obviously down-regulated. Above all, ARTs may inhibit the proliferation of glioblastoma cells by arresting cell cycle in G0/G1 phase through down-regulating the expression of CDK2, CDK4, cyclin D1, cyclin B1. These results may not only provide a novel method for rediscovering and reusing ARTs but also provide a new potential drug for treating glioblastoma.

Vitex rotundifolia Fruit Suppresses the Proliferation of Human Colorectal Cancer Cells through Down-regulation of Cyclin D1 and CDK4 via Proteasomal-Dependent Degradation and Transcriptional Inhibition.

Viticis Fructus (VF) as the dried fruit from Vitex rotundifolia L. used as a traditional medicine for treating inflammation, headache, migraine, chronic bronchitis, eye pain, and gastrointestinal infections has been reported to have antiproliferative effects against various cancer cells, including breast, lung and colorectal cancer cells. However, the molecular mechanisms by which VF mediates the inhibitory effect of the proliferation of cancer cells have not been elucidated in detail. In this study, we investigated the molecular mechanism of VF on the down-regulation of cyclin D1 and CDK4 level associated with cancer cell proliferation. VF suppressed the proliferation of human colorectal cancer cell lines such as HCT116 and SW480. VF induced decrease in cyclin D1 and CDK4 in both protein and mRNA levels. However, the protein levels of cyclin D1 and CDK4 were decreased by VF at an earlier time than the change of mRNA levels; rather it suppressed the expression of cyclin D1 and CDK4 via the proteasomal degradation. In cyclin D1 and CDK4 degradation, we found that Thr286 phosphorylation of cyclin D1 plays a pivotal role in VF-mediated cyclin D1 degradation. Subsequent experiments with several kinase inhibitors suggest that VF-mediated degradation of cyclin D1 may be dependent on GSK3[Formula: see text] and VF-mediated degradation of CDK4 is dependent on ERK1/2, p38 and GSK3[Formula: see text]. In the transcriptional regulation of cyclin D1 and CDK4, we found that VF inhibited Wnt activation associated with cyclin D1 transcriptional regulation through TCF4 down-regulation. In addition, VF treatment down-regulated c-myc expression associated CDK4 transcriptional regulation. Our results suggest that VF has potential to be a candidate for the development of chemoprevention or therapeutic agents for human colorectal cancer.

Bioactive fraction of Rhodiola algida against chronic hypoxia-induced pulmonary arterial hypertension and its anti-proliferation mechanism in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Rhodiola algida var. tangutica (Maxim.) S.H. Fu is a perennial plant of the Crassulaceae family that grows in the mountainous regions of Asia. The rhizome and roots of this plant have been long used as Tibetan folk medicine for preventing high latitude sickness. AIM OF THE STUDY: The aim of this study was to determine the effect of bioactive fraction from R. algida (ACRT) on chronic hypoxia-induced pulmonary arterial hypertension (HPAH) and to understand the possible mechanism of its pharmacodynamic actions. MATERIALS AND METHODS: Male Sprague-Dawley rats were separated into five groups: control group, hypoxia group, and hypoxia+ACRT groups (62.5, 125, and 250mg/kg/day of ACRT). The chronic hypoxic environment was created in a hypobaric chamber by adjusting the inner pressure and oxygen content for 4 weeks. After 4 weeks, major physiological parameters of pulmonary arterial hypertension such as mPAP, right ventricle index (RV/LV+S, RVHI), hematocrit (Hct) levels and the medial vessel thickness (wt%) were measured. Protein and mRNA expression levels of proliferating cell nuclear antigen (PCNA), cyclin D1, p27Kip1 and cyclin-dependent kinase 4 (CDK4)) were detected by western blotting and real time PCR respectively. Chemical profile of ACRT was revealed by ultra performance liquid chromatography coupled with quadrupole time of flight mass spectrometry (UHPLC-Q-TOF-MS/MS). RESULTS: The results showed that a successful HPAH rat model was established in a hypobaric chamber for 4 weeks, as indicated by the significant increase in mPAP, RV/LV+S, RV/BW and wt%. Compared with the normal group, administration of ACRT reduced mPAP, right ventricular hypertrophy, pulmonary small artery wall thickness, and damage in ultrastructure induced by hypoxia in rats. PCNA, cyclin D1, and CDK4 expression was reduced (p<0.05), and p27Kip1 expression increased (p<0.05) in hypoxia+ACRT groups compared to hypoxia. 38 constituents in bioactive fraction were identified by UHPLC-Q-TOF-MS/MS. CONCLUSION: Our results suggest that ACRT could alleviate chronic hypoxia-induced pulmonary arterial hypertension. And its anti-proliferation mechanism in rats based on decreasing PCNA, cyclin D1, CDK4 expression level and inhibiting p27Kip1 degradation.