Artonin E induces p53-independent g1 cell cycle arrest and apoptosis through ROS-mediated mitochondrial pathway and livin suppression in MCF-7 cell

Artonin E is a prenylated flavonoid compound isolated from the stem bark of Artocarpus elasticus. This phytochemical has been previously reported to be drug-like with full compliance to Lipinski's rule of five and good physicochemical properties when compared with 95% of orally available drugs. It has also been shown to possess unique medicinal properties that can be utilized in view of alleviating most human disease conditions. In this study, we investigated the cytotoxic mechanism of Artonin E in MCF-7 breast cancer cells, which has so far not been reported. In this context, Artonin E significantly suppressed the breast cancer cell's viability while inducing apoptosis in a dose-dependent manner. This apoptosis induction was caspase dependent, and it is mediated mainly through the intrinsic pathway with the elevation of total reactive oxygen species. Gene and protein expression studies revealed significant upregulation of cytochrome c, Bax, caspases 7 and 9, and p21 in Artonin E-treated MCF-7 cells, while MAPK and cyclin D were downregulated. Livin, a member of the inhibitors of apoptosis, whose upregulation has been noted to precede chemotherapeutic resistance and apoptosis evasion was remarkably repressed. In all, Artonin E stood high as a potential agent in the treatment of breast cancer

Notes and Comments on Recent Decisions

Background Breast cancer is still a leading cause of cancer death among women. Thus, therapeutic alternatives from nature should be explored to lessen this burden. This is vital owing to the common occurrences of resistance in conventional therapies alongside their alarming side effects. Aims This study was carried out to investigate the inhibitory effect of Artonin E in female mice bearing 4T1 mammary tumour. Methods 4T1 cells in 100 mu L PBS were injected into the right mammary fat pad of each female Balb/c mice aged between six to eight weeks. Treatment was commenced when the palpable tumour attained a size of 50-200mm(3). The treatment groups included Artonin E, at dosages of 25mg/kg, 50mg/kg and 100mg/kg per oral bi-weekly, 10mg/kg of paclitaxel weekly and 5 percent tween 20 biweekly. Tumour volume and body weight changes were recorded at the staging day and then twice every week throughout the study period. At the end of the study, the vital tissues were collected for histopathologcal assessment and blood samples were taken for serum biochemical analyses. Results From the results, the group treated with either 50mg/kg or 100mg/kg of Artonin E showed a significant (p<0.05) reduction in tumour volume. Artonin E delayed quadruple tumour growth by more than five days in comparison to the untreated control group. Histopathology and biochemical analysis revealed no toxicity in the dosages of artonin E used in this study. Secondary tumour, which had metastasized to distant organs were seen to reduce upon treatment with Artonin E. Conclusion With the capacity to reduce in vivo tumour growth, Artonin E has a great prospect to be developed into an anticancer agent

Reduction of breast tumor burden in mice by a prenylated flavonoid, Artonin E

BackgroundBreast cancer is still a leading cause of cancer death among women. Thus, therapeutic alternatives from nature should be explored to lessen this burden. This is vital owing to the common occurrences of resistance in conventional therapies alongside their alarming side effects.AimsThis study was carried out to investigate the inhibitory effect of Artonin E in female mice bearing 4T1 mammary tumour.Methods 4T1 cells in 100µL PBS were injected into the right mammary fat pad of each female Balb/c mice aged between six to eight weeks. Treatment was commenced when the palpable tumour attained a size of 50–200mm3. The treatment groups included Artonin E, at dosages of 25mg/kg, 50mg/kg and 100mg/kg per oral bi-weekly, 10mg/kg of paclitaxel weekly and 5 percent tween 20 bi-weekly. Tumour volume and body weight changes were recorded at the staging day and then twice every week throughout the study period. At the end of the study, the vital tissues were collected for histopathologcal assessment and blood samples were taken for serum biochemical analyses.Results From the results, the group treated with either 50mg/kg or 100mg/kg of Artonin E showed a significant (p < 0.05) reduction in tumour volume. Artonin E delayed quadruple tumour growth by more than five days in comparison to the untreated control group. Histopathology and biochemical analysis revealed no toxicity in the dosages of artonin E used in this study. Secondary tumour, which had metastasized to distant organs were seen to reduce upon treatment with Artonin E.ConclusionWith the capacity to reduce in vivo tumour growth, Artonin E has a great prospect to be developed into an anticancer agent

Anti-breast cancer effect and molecular mechanism of action of artonin e using In Silico, In Vitro and In Vivo approaches

In spite of advances in medicine, breast cancer still remains a leading cause of death among women worldwide. The resistance and high toxicity ensuing from available modern breast cancer treatment regimens have reduced the survival rate, causing most cancer patients to seek natural remedies with fewer side-effects as alternatives. This study was conducted to investigate the anti-breast cancer effect and elucidate the molecular mechanism of action of Artonin E, a prenylated flavonoid extracted from the stem bark of Artocarpus elasticus. The in silico anti-cancer effect of Artonin E was evaluated by targeting the human estrogen receptor α (hERα), present in approximately 70% of breast cancers. The Glide, Schrodinger Suite 2015 was used in the molecular docking study. The structure of the ligand binding domain of hERα was retrieved from Protein Data Bank while the structures of compounds were collected from PubChem database and prepared with the Schrodinger Suite. The compounds: Artonin E, Artobiloxanthone, Cycloartocarpesin, Artelastin, Artonin Y, Artonin U, Artonin L, Artonin T, Artonin S, Tamoxifen and the native ligand, were first examined for their drug-likeness before the conduct of the docking study. The cytotoxicity and mode of cell death induced by Artonin E on breast cancer cells were examined in vitro using the 3- (4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, acridine orange (AO) and propidium iodide (PI) double staining, annexin V/FITC staining and DNA fragmentation analysis. Caspase-8 and -9 assays, total reactive oxygen species (ROS) assay, apoptosis- and cell cycle-related gene expression, human apoptosis proteome profiling array and Western blot analyses were used to determine the mechanism of apoptosis induced by Artonin E on MCF-7 and MDA-M-231 cells. The regulation of the breast cancer cell cycle was also investigated using flowcytometry. In the in vivo study, the mouse 4TI cell-induced mammary gland tumor model was used. The development of the tumor in mice was investigated over the 28 days of bi-weekly oral treatment with Artonin E. Serum biochemical parameters and liver, lung and kidney histopathology of treated mice were analysed. From the docking study, Artonin E had the best glide score among analogues of similar structure from the Artocarpus species and was chosen as a lead for further studies. Artonin E was shown to produce a half-maximal growth inhibition in MCF-7 cells at concentrations of 6.9, 5.1 and 3.8 μM and in MDA-MB-231 at 14.3, 13.9 and 9.8 μM after 24, 48 and 72 hours of treatment, respectively. The greater cytotoxicity of Artonin E on MCF-7 when compared to MDAMB- 231 cells was confirmed by AO/PI and annexin V-FITC assays, thus, validating its strong binding affinity to the hERα, as shown by the molecular docking studies. Artonin E was less toxic to the normal breast epithelial (MCF 10A) cell line with IC50 of 45.80 μM. The morphological analysis and cell viability assay showed that the breast cancer cells treated with Artonin E lost viability and underwent apoptosis. Artonin E induced p53 independent G1 cell cycle arrest and apoptosis through ROS mediated mitochondrial pathway and livin suppression in MCF-7 breast cancer cells. It downregulated antiapoptotic proteins with a corresponding upregulation of apoptosis inducers and caused a G2/M cell cycle arrest in MDA-MB 231 cells. These observations were evident by the gene expression analysis, caspase assay, ROS assays, apoptosis profiling and Western blot analysis. In the mouse mammary gland tumor model, Artonin E significantly (p<0.05) delayed tumor growth and reduced the relative tumor volume in a dosedependent manner. By histopathological examination, the mammary gland tumor in mice treated with Artonin E showed lesser metastasis in a dose-dependent manner compared to the untreated control. Thus, this study showed that Artonin E has great potential to be developed as an anti-breast cancer agent

Artonin E and Structural Analogs from Artocarpus Species Abrogates Estrogen Receptor Signaling in Breast Cancer

The increasing rate of mortality ensued from breast cancer has encouraged research into safer and efficient therapy. The human Estrogen receptor α has been implicated in the majority of reported breast cancer cases. Molecular docking employing Glide, Schrodinger suite 2015, was used to study the binding affinities of small molecules from the Artocarpus species after their drug-like properties were ascertained. The structure of the ligand-binding domain of human Estrogen receptor α was retrieved from Protein Data Bank while the structures of compounds were collected from PubChem database. The binding interactions of the studied compounds were reported as well as their glide scores. The best glide scored ligand, was Artonin E with a score of −12.72 Kcal when compared to other studied phytomolecules and it evoked growth inhibition of an estrogen receptor positive breast cancer cells in submicromolar concentration (3.8–6.9 µM) in comparison to a reference standard Tamoxifen (18.9–24.1 µM) within the tested time point (24–72 h). The studied ligands, which had good interactions with the target receptor, were also drug-like when compared with 95% of orally available drugs with the exception of Artoelastin, whose predicted physicochemical properties rendered it less drug-like. The in silico physicochemical properties, docking interactions and growth inhibition of the best glide scorer are indications of the anti-breast cancer relevance of the studied molecules

In Silico Discovery of Potential Uridine-Cytidine Kinase 2 Inhibitors from the Rhizome of Alpinia mutica

Uridine-cytidine kinase 2 is implicated in uncontrolled proliferation of abnormal cells and it is a hallmark of cancer, therefore, there is need for effective inhibitors of this key enzyme. In this study, we employed the used of in silico studies to find effective UCK2 inhibitors of natural origin using bioinformatics tools. An in vitro kinase assay was established by measuring the amount of ADP production in the presence of ATP and 5-fluorouridine as a substrate. Molecular docking studies revealed an interesting ligand interaction with the UCK2 protein for both flavokawain B and alpinetin. Both compounds were found to reduce ADP production, possibly by inhibiting UCK2 activity in vitro. In conclusion, we have identified flavokawain B and alpinetin as potential natural UCK2 inhibitors as determined by their interactions with UCK2 protein using in silico molecular docking studies. This can provide information to identify lead candidates for further drug design and development

In Silico Discovery of Potential Uridine-Cytidine Kinase 2 Inhibitors from the Rhizome of Alpinia mutica

Uridine-cytidine kinase 2 is implicated in uncontrolled proliferation of abnormal cells and it is a hallmark of cancer, therefore, there is need for effective inhibitors of this key enzyme. In this study, we employed the used of in silico studies to find effective UCK2 inhibitors of natural origin using bioinformatics tools. An in vitro kinase assay was established by measuring the amount of ADP production in the presence of ATP and 5-fluorouridine as a substrate. Molecular docking studies revealed an interesting ligand interaction with the UCK2 protein for both flavokawain B and alpinetin. Both compounds were found to reduce ADP production, possibly by inhibiting UCK2 activity in vitro. In conclusion, we have identified flavokawain B and alpinetin as potential natural UCK2 inhibitors as determined by their interactions with UCK2 protein using in silico molecular docking studies. This can provide information to identify lead candidates for further drug design and development

Clausenidin induces caspase-dependent apoptosis in colon cancer

Background: Clausena excavata burm.f. Is a shrub traditionally used to treat cancer patients in asia. The main bioactive chemical components of the plant are alkaloids and coumarins. In this study, we isolated clausenidin from the roots of c. Excavata to determine its apoptotic effect on the colon cancer (ht-29) cell line. Method: We examined the effect of clausenidin on cell viability, ros generation, dna fragmentation, mitochondrial membrane potential in ht-29 cells. Ultrastructural analysis was conducted for morphological evidence of apoptosis in the treated ht-29 cells. In addition, we also evaluated the effect of clausenidin treatment on the expression of caspase 3 and 9 genes and proteins in ht-29 cells. Result: Clausenidin induced a g0/g1 cell cycle arrest in ht-29 cells with significant (p < 0.05) dose-dependent increase in apoptotic cell population. The dna fragmentation assay also showed apoptotic features in the clausenidin-treated ht-29 cells. Clausenidin treatment had caused significant (p < 0.05) increases in the expression of caspase 9 protein and gene in ht-29 cells and mitochondrial ros and mitochondrial membrane depolarization. The results suggest the involvement of the mitochondria in the caspase-dependent apoptosis in clausenidin-treated colon cancer cells. Conclusion: Clausenidin induces a caspase-dependent apoptosis in colon cancers through the stimulation of the mitochondria. The study demonstrates the potential of clausenidin for use in the treatment of colon cancers