Isolation, Structure Elucidation and in Vitro Anticancer Activity of Phytochemical Constituents of Goniothalamus wynaadensis Bedd. and Identification of α-Tubulin as a Putative Molecular Target by in Silico Study

The phytochemical analysis of ethyl acetate and methanol extract of Goniothalamus wynaadensis Bedd. leaves led to an isolation of eight (1-8) known molecules, among them seven (2-8) isolated for the first time from this species, which includes (+)-goniothalamin oxide (2), goniodiol-7-monoacetate (3), goniodiol-8-monoacetate (4), goniodiol (5), (+)-8-epi-9-deoxygoniopypyrone (6) etc. The phytochemical modification by acetylation of 3 and 4 gave goniodiol diacetate (9) with absolute configuration (6R, 7R, 8R) confirmed by single crystal X-ray diffraction. Compounds 3-9 were cytotoxic against breast, ovarian, prostate and colon cancer cell lines with IC50 <10 μM. Cell cycle analysis and Annexin-V assay on MDA-MB-231 cell using goniodiol-7-monoacetate (3) exhibited apoptotic response as well as necrotic response and showed cell proliferation arrest at G2/M phase. An in silico target identification for these molecules was carried out with an α-tubulin protein target by covalent docking. To gain an in-depth understanding and identify the stability of these protein-ligand complexes on thermodynamic energy levels, further assessment of the isolated molecules binding to the Cys-316 of α-tubulin was performed based on reaction energetic analysis via DFT studies which hinted the isolated molecules may be α-tubulin inhibitors similar to Pironetin. Molecular dynamics reiterated the observations.

Combination of Goniothalamin and Sol-Gel-Derived Bioactive Glass 45S5 Enhances Growth Inhibitory Activity via Apoptosis Induction and Cell Cycle Arrest in Breast Cancer Cells MCF-7

BACKGROUND

Combination of natural products with chemically synthesised biomaterials as cancer therapy has attracted great interest lately. Hence, this study is aimed at investigating the combined effects of goniothalamin and bioactive glass 45S5 (GTN-BG) and evaluating their anticancer properties on human breast cancer cells MCF-7.

METHODS

The BG 45S5 was prepared using the sol-gel process followed by characterisation using PSA, BET, SEM/EDS, XRD, and FTIR. The effects of GTN-BG on the proliferation of MCF-7 were assessed by MTT, PrestoBlue, and scratch wound assays. The cell cycle analysis, Annexin-FITC assay, and activation of caspase-3/7, caspase-8, and caspase-9 assays were determined to further explore its mechanism of action.

RESULTS

The synthesised BG 45S5 was classified as a fine powder, having a rough surface, and contains mesopores of 12.6 nm. EDS analysis revealed that silica and calcium elements are the primary components of BG powders. Both crystalline and amorphous structures were detected with 73% and 27% similarity to Na2Ca2(Si2O7) and hydroxyapatite, respectively. The combination of GTN-BG was more potent than GTN in inhibiting the proliferation of MCF-7 cells. G0/G1 and G2/M phases of the cell cycle were arrested by GTN and GTN-BG. The percentage of viable cells in GTN-BG treatment was significantly lower than that in GTN. In terms of activation of initiator caspases for both extrinsic and intrinsic apoptosis pathways, caspase-8 and caspase-9 were found more effective in response to GTN-BG than GTN.

CONCLUSION

The anticancer effect of GTN in MCF-7 cells was improved when combined with BG. The findings provide significant insight into the mechanism of GTN-BG against MCF-7 cells, which can potentially be used as a novel anticancer therapeutic approach.

Cytotoxic cobalt (III) Schiff base complexes: in vitro anti-proliferative, oxidative stress and gene expression studies in human breast and lung cancer cells

Increasing cancer drug chemo-resistance, especially in the treatment of breast and lung cancers, alarms the immediate need of newer and effective anticancer drugs. Until now, chemotherapeutics based on metal complexes are considered the most effective treatment modality. In the present study, we have evaluated the cytotoxic effect of two cobalt (III) Schiff base complexes based on the leads from complex combinatorial chemistry. Cobalt (III) Schiff base complexes (Complex 3 = Co(Ph-acacen)(HA)₂](ClO₄) and Complex 4 =  [Co(Ph-acacen)(DA)₂](ClO₄)] (Ph-acacen, 1-phenylbutane-1,3-dione; DA, dodecyl amine; HA, heptylamine) were evaluated against human breast cancer cell MCF-7 and lung cancer cell A549 using MTT cell viability assay, cellular morphological changes studied by Acridine Orange and Ethidium Bromide (AO/EB), Dual fluorescent staining, Hoechst staining 33248, Comet assay, Annexin V-Cy3 and 6 CFDA assay, JC-1 staining, Reactive oxygen species (ROS) assay, Immunofluorescence assay, and Real-time reverse transcription-polymerase chain reaction (RT-qPCR). Treatment of cobalt (III) Schiff base complexes (Complex 3 & 4) affected the viability of the cancer cells. The cell death induced by the complexes was predominantly apoptosis, but necrosis also occurred to a certain extent. Complex 4 produced better cytotoxic effect than complex 3, and MCF-7 cell was more responsive than A549. In that order, the complexes were more selective to cancer cell than normal cell, and more effective in overall performance than the standard drug cisplatin. Therefore, we conclude that cobalt (III) Schiff base complexes, especially complex 4, have the potential to be developed as effective drugs for treatment of cancers in general, and breast and lung cancers in particular.

Apoptotic Activity of New Oxisterigmatocystin Derivatives from the Marine-Derived Fungus Aspergillus nomius NC06

Sponge-derived fungi have recently attracted attention as an important source of interesting bioactive compounds. Aspergillus nomius NC06 was isolated from the marine sponge Neopetrosia chaliniformis. This fungus was cultured on rice medium and yielded four compounds including three new oxisterigmatocystins, namely, J, K, and L (1, 2, and 3), and one known compound, aspergillicin A (4). Structures of the compounds were elucidated by 1D and 2D NMR spectroscopy and by high-resolution mass spectrometry. The isolated compounds were tested for cytotoxic activity against HT 29 colon cancer cells, where compounds 1, 2, and 4 exhibited IC50 values of 6.28, 15.14, and 1.63 µM, respectively. Under the fluorescence microscope by using a double staining method, HT 29 cells were observed to be viable, apoptotic, and necrotic after treatment with the cytotoxic compounds 1, 2, and 4. The result shows that compounds 1 and 2 were able to induce apoptosis and cell death in HT 29 cells.

Interaction between goniothalamin and peroxisomal multifunctional enzyme type 2 triggering endoplasmic reticulum stress

Endoplasmic reticulum stress is one of the pathways involved in cell cytotoxicity. In this study, goniothalamin, one of styryllactone compounds found in plant Goniothalamus spp., was observed to trigger ER stress in HeLa cell line. In addition, we demonstrated that peroxisomal multifunctional enzyme type2 (MFE2) was a specific goniothalamin-binding protein using an in vitro goniothalamin-linked bead pull-down assay. Since MFE2 has been reported to be an important mediator enzyme for peroxisomal β-oxidation of a very long chain fatty acid metabolism, therefore computational molecular docking analysis was performed to confirm the binding of goniothalamin and MFE2. The results indicated that goniothalamin structure binds to scp-2 domain, enoyl-CoA hydratase 2 domain and (3R)-hydroxyacyl-CoA dehydrogenase domain of MFE2. To further determine the effect of MFE2 on ER stress induction, MFE2 knockdown by siRNA in HeLa cell was conducted. The results implied that MFE2 triggered CHOP, a key mediator of ER stress-induced apoptosis, expression. Therefore, these data inferred that goniothalamin may interrupt the MFE2 function resulting in lipid metabolism perturbation associated with ER stress-independent activation of unfolded protein response. This is the first report to show that goniothalamin binds directly to MFE2 triggering ER stress activation probably through the lipid metabolism perturbation.

Design and synthesis of novel 4-thiazolidinone derivatives with promising anti-breast cancer activity: Synthesis, characterization, in vitro and in vivo results

Novel lead compounds as anticancer agents with the ability to circumvent emerging drug resistance have recently gained a great deal of interest. Thiazolidinones are among such compounds with well-established biological activity in the field of oncology. Here, we designed, synthesized and characterized a series of thiazolidinone structures (8a-8k). The results of anti-proliferative assay led to the discovery of compound 8j with a high potent cytotoxic effect using colon, liver and breast cancer cells. Furthermore, MDA-MB-231 and 4T1 cell lines were used to represent triple negative breast cancer (TNBC). Next, a number of in vitro and in vivo evaluations were carried out to demonstrate the potential activity against TNBC and also elucidate the possible mechanism of cell death induction. Our in vitro outcomes exhibited an impressive anticancer activity for compound 8j toward MDA-MB-231 cells through inducing apoptosis and a remarkable anti-metastatic feature via suppressing MMP-9 expression as well. Consistently, the in vivo and immunohistopathologic evaluations demonstrated that this compound significantly inhibited the 4T1 induced tumor growth and its metastasis to the lung. Altogether, among numerous thiazolidinone derivatives, compound 8j might represent a promising anticancer agent for TNBC, which is a major concern in the developed and developing countries.

Improved delivery of doxorubicin using rationally designed PEGylated platinum nanoparticles for the treatment of melanoma

Efficient delivery of chemotherapeutic drugs to tumor cells is one of the crucial issues for modern day cancer therapy. In this article, we report the synthesis of poly ethylene glycol (PEG) assisted colloidal platinum nanoparticles (PtNPs) by borohydride reduction method at room temperature. PtNPs are stable at room temperature for more than 2 years and are stable in serum and phosphate buffer (pH = 7.4) solution for one week. PtNPs show biocompatibility in different normal cell lines (in vitro) and chicken egg embryonic model (ex vivo). Further, we designed and fabricated PtNPs-based drug delivery systems (DDS: PtNPs-DOX) using doxorubicin (DOX), a FDA approved anticancer drug. Various analytical techniques were applied to characterize the nanomaterials (PtNPs) and DDS (PtNPs-DOX). This DDS exhibits inhibition of cancer cell (B16F10 and A549) proliferation, observed by different in vitro assays. PtNPs-DOX induces apoptosis in cancer cells observed by annexin-V staining method. Intraperitoneal (IP) administration of PtNPs-DOX shows substantial reduction of tumor growth in subcutaneous murine melanoma tumor model compared to control group with free drug. Up-regulation of tumor suppressor protein p53 and down regulation of SOX2 and Ki-67 proliferation markers in melanoma tumor tissues (as observed by immunofluorescence and western blot analysis) indicates probable molecular mechanism for the anticancer activity of DDS. Considering the in vitro and pre-clinical (in vivo) results in murine melanoma, it is believed that platinum nanoparticle-based drug delivery formulation could be exploited to develop an alternative therapeutic nanomedicine for cancer therapy in the near future.

Antiproliferative activity of (R)-4'-methylklavuzon on hepatocellular carcinoma cells and EpCAM+/CD133+ cancer stem cells via SIRT1 and Exportin-1 (CRM1) inhibition

Cytotoxic effects of (R)-4'-methylklavuzon were investigated on hepatocellular carcinoma cells (HuH-7 and HepG2) and HuH-7 EpCAM+/CD133+ cancer stem cells. IC50 of (R)-4'-methylklavuzon was found as 1.25 μM for HuH-7 parental cells while it was found as 2.50 μM for HuH-7 EpCAM+/CD133+ cancer stem cells. (R)-4'-methylklavuzon tended to show more efficient in vitro cytotoxicity with its lower IC50 values on hepatocellular carcinoma cell lines compared to its lead molecule, goniothalamin and FDA-approved drugs, sorafenib and regorafenib. Cell-based Sirtuin/HDAC enzyme activity measurements revealed that endogenous Sirtuin/HDAC enzymes were reduced by 40% compared to control. SIRT1 protein levels were upregulated indicating triggered DNA repair mechanism. p53 was overexpressed in HepG2 cells. (R)-4'-methylklavuzon inhibited CRM1 protein providing increased retention of p53 and RIOK2 protein in the nucleus. HuH-7 parental and EpCAM+/CD133+ cancer stem cell spheroids lost intact morphology. 3D HepG2 spheroid viabilities were decreased in a correlation with upregulation in p53 protein levels.

Histological, Biochemical, and Hematological Effects of Goniothalamin on Selective Internal Organs of Male Sprague-Dawley Rats

Goniothalamin (GTN) is an isolated compound from several plants of the genus Goniothalamus, and its anticancer effect against several cancers was reported. However, there is no scientific data about effects of its higher doses on internal organs. Accordingly, this study aimed to evaluate the acute and subacute effects of higher doses of GTN on the hematology, biochemistry, and histology of selected internal organs of male Sprague-Dawley rats. In acute study, 35 rats were distributed in 5 groups (n=7) which were intraperitoneally (IP) injected with a single dose of either 100, 200, 300, 400, or 500 mg/kg of GTN, while extra 7 rats serve as a normal control. In subacute study, 7 rats were IP-injected with a daily dose of 42 mg/kg of GTN for 14 days, while another 7 rats serve as a normal control group. The normal controls in both studies were IP-injected simultaneously with 2 ml/kg of 10% DMSO in PBS. At the end of both tests, rats were sacrificed to collect blood for hematology and biochemistry and harvest livers, kidneys, lungs, hearts, spleens, and brains for histology. During acute and subacute exposure, no abnormal changes were observed in the hematology, biochemistry, and histology of the internal organs. However, the 300, 400, and 500 mg/kg of GTN during acute exposure were associated with morbidities and mortalities. Ultimately, GTN could be safe up to the dose of 200 mg/kg, and the dose of 42 mg/kg of GTN was tolerated well.

Tohid SF. Dicranopteris linearis extract inhibits the proliferation of human breast cancer cell line (MDA-MB-231) via induction of S-phase arrest and apoptosis

CONTEXT

Dicranopteris linearis (Burm.f.) Underw. (Gleicheniaceae) has been scientifically proven to exert various pharmacological activities. Nevertheless, its anti-proliferative potential has not been extensively investigated.

OBJECTIVE

To investigate the anti-proliferative potential of D. linearis leaves and determine possible mechanistic pathways.

MATERIALS AND METHODS

MTT assay was used to determine the cytotoxic effects of D. linearis methanol (MEDL) and petroleum ether (PEEDL) extracts at concentrations of 100, 50, 25, 12.5, 6.25 and 3.125 µg/mL against a panel of cancer cell lines (breast [MCF-7 and MDA-MB-231], cervical [HeLa], colon [HT-29], hepatocellular [HepG2] and lung [A549]), as compared to negative (untreated) and positive [5-fluorouracil (5-FU)-treated] control groups. Mouse fibroblast cells (3T3) were used as normal cells. The mode of cell death was examined using morphological analysis via acridine orange (AO) and propidium iodide (PI) double staining. Cell cycle arrest was determined using flow cytometer, followed by annexin V-PI apoptosis detection kit.

RESULTS

MEDL demonstrated the most significant growth inhibition against MDA-MB-231 cells (IC₅₀ 22.4 µg/mL). PEEDL showed no cytotoxic effect. Induction of apoptosis by MEDL was evidenced via morphological analysis and acridine orange propidium iodide staining. MEDL could induce S phase cell cycle arrest after 72 h of incubation. Early apoptosis induction in MDA-MB-231 cells was confirmed by annexin V-FITC and PI staining. Significant increase in apoptotic cells were detected after 24 h of treatment with 15.07% cells underwent apoptosis, and the amount escalated to 18.24% with prolonged 48 h incubation.

CONCLUSIONS

MEDL has potential as a potent cytotoxic agent against MDA-MB-231 adenocarcinoma.

Goniothalamin-Related Styryl Lactones: Isolation, Synthesis, Biological Activity and Mode of Action

This review covers the chemistry and biological aspects of goniothalamin-related styryl lactones isolated from natural sources. This family of secondary metabolites has been reported to display diverse uses in folk medicine, but only a limited number of these compounds have been throughly investigated regarding their biological profile. Herein, we cover the goniothalamin-related styryl lactones having a C6-C3-C4 framework which appeared in the literature for the first time in the period 2000-2017, and the reports on the synthesis, biological activity and mechanism of action which were published from 2007-2017.

Mechanism of apoptosis induction associated with ERK1/2 upregulation via goniothalamin in melanoma cells

The present study aimed to investigate the effect of goniothalamin on apoptosis induction in the A375 melanoma cell line. Melanoma is a type of skin cancer with increased prevalence and no potential standard treatment. Goniothalamin is a plant, bioactive styrly-lactone, which has various bioactivities including anti-microbial, anti-inflammatory and anti-cancer. Apoptosis induction by goniothalamin has been studied in numerous cancer cell lines, however not in the melanoma cell line A375. The results of the MTT assay demonstrated that goniothalamin induced anti-proliferation in a dose dependent manner. Hoechst staining assay demonstrated that goniothalamin induced chromatin condensation and apoptotic bodies in A375 treated cells, and JC-1 staining revealed that goniothalamin induced mitochondrial membrane dysfunction in A375 cells. In addition, goniothalamin decreased the level of anti-apoptotic proteins myeloid cell leukemia 1, B cell lymphoma (Bcl)-2 and Bcl-extra large, whereas it increased the level of pro-apoptotic proteins, Bcl-2 Associated X, apoptosis regulator, t-BID and Bim in A375 treated cells. In addition, goniothalamin also increased active caspase-9, -7 and cleaved-poly (ADP-ribose) polymerase expression in A375 treated cells. Furthermore, phosphorylated (p)-pyruvate dehydrogenase kinase (PDK) 1 (Ser241) and p-RAC-alpha serine/threonine-protein kinase (Akt; Ser473) were decreased, however c-Jun and p-extracellular signal-regulated kinase (ERK)1/2 were increased upon goniothalamin treatment. These results suggest that goniothalamin has an effect, as anti-proliferation and apoptosis induction in A375 cells were associated with upregulated p-ERK1/2, c-Jun and downregulated p-PDK1 (Ser241), p-Akt (Ser473) in A375 cells. Therefore, goniothalamin may be a potential candidate for anti-cancer drug development for melanoma treatment.

Effects of Damnacanthal and Nordamnacanthal on Proliferation, Apoptosis, and Migration of Oral Squamous Cell Carcinoma Cells

Cancer is one of the most common causes of death in the developed world, with one-third of people diagnosed with cancer during their lifetime. Oral cancer commonly occurs involving the buccal mucosa (cheeks), tongue, floor of the mouth and lip. It is one of the most devastating and disfiguring of malignancies. Morinda citrifolia L., commonly known as ‘noni’, belongs to the Rubiaceae family. It is native to the Pacific islands, Hawaii, Caribbean, Asia and Australia. The plant displays broad curative effects in pharmacological studies. Damnacanthal (DAM) and Nordamnacanthal (NDAM), anthraquinone compounds isolated from the roots of Morinda citrifolia L., has been used for the treatment of several chronic diseases including cancer. The objectives of this study were to evaluate cytotoxicity, morphological changes, cell death mode (apoptosis/necrosis), and cell migration induced by DAM and NDAM on the most common type of oral cancer, oral squamous cell carcinoma (OSCC)cells. Anti-proliferative effects of these compounds against OSCC cell lines were determined by MTT assay. The mode of cell death was analysed by phase contrast and fluorescent microscopy as well as flow cytometry. In addition, cell migration was assessed. The results showed that DAM and NDAM exerted cytotoxicity against OSCC cells with IC₅₀ values of 1.9 to >30 μg/ml after 72 h treatment. Maximum growth inhibition among the tested cell lines for both compounds was observed in H400 cells, and thus it was selected for further study. The study demonstrated inhibition of H400 OSCC cell proliferation, marked apoptotic morphological changes, induction of early apoptosis, and inhibition of cell migration by DAM and NDAM. Therefore, this information suggests that these compounds from noni have potential for used as anti tumor agents for oral cancer therapy.

Multifunctional (3-in-1) cancer theranostics applications of hydroxyquinoline-appended polyfluorene nanoparticles

The accumulation of fluorescent hydroxyquinoline-affixed polyfluorene (PF-HQ) nanoparticles and their utility for multi-color bio-imaging and drug delivery for cancer treatment are reported. The formation of nanoparticles (PF-HQ) containing hydrophobic pockets via three-dimensional growth of a polymeric backbone in a higher water fraction (THF : H2O = 1 : 9) was observed. The nanoparticles showed incredible dual-state optical and fluorescence properties, which were further explored in multi-color cell imaging in both cancer and normal cells. The cell viability assay in various normal cells confirmed the biocompatible nature of PF-HQ, which was further supported by an ex vivo (chick chorioallantoic membrane assay) model. This encouraged us to fabricate PF-HQ-based new drug delivery systems (DDS: PF-HQ-DOX) upon conjugation with the FDA-approved anti-cancer drug doxorubicin (DOX) by filling the hydrophobic pockets of the polymer nanoparticles. The enhanced anti-cancer activity of the DDS (PF-HQ-DOX) compared with that of free DOX was observed in mouse melanoma cancer cells (B16F10) and a subcutaneous mouse (C57BL6/J) melanoma tumor model upon administration of PF-HQ-DOX. Ex vivo biodistribution studies using a fluorescence quantification method demonstrated the enhanced accumulation of DOX in tumor tissues in the PF-HQ-DOX-treated group compared to that of the free drug, signifying the drug delivery efficacy of the delivery system by a passive targeting manner. Based on the above biological data (in vitro and in the pre-clinical model), these robust and versatile fluorescent hydroxyquinoline-affixed polyfluorene (PF-HQ) nanoparticles could be effectively utilized for multifunctional biomedical applications (as they are biocompatible and can be used for bio-imaging and as a drug delivery vehicle).

Efficiency of newly formulated camptothecin with β-cyclodextrin-EDTA-Fe3O4 nanoparticle-conjugated nanocarriers as an anti-colon cancer (HT29) drug

Camptothecin (CPT) is an anti-cancer drug that effectively treats various cancers, including colon cancer. However, poor solubility and other drawbacks have restricted its chemotherapeutic potential. To overcome these restrictions, CPT was encapsulated in CEF (cyclodextrin-EDTA-FE₃O₄), a composite nanoparticle of magnetic iron oxide (Fe₃O₄), and β-cyclodextrin was cross-linked with ethylenediaminetetraacetic acid (EDTA). This formulation improved CPT’s solubility and bioavailability for cancer cells. The use of magnetically responsive anti-cancer formulation is highly advantageous in cancer chemotherapy. The chemical characterisation of CPT-CEF was studied here. The ability of this nano-compound to induce apoptosis in HT29 colon cancer cells and A549 lung cancer cells was evaluated. The dose-dependent cytotoxicity of CPT-CEF was shown using MTT. Propidium iodide and Annexin V staining, mitochondrial membrane depolarisation (JC-1 dye), and caspase-3 activity were assayed to detect apoptosis in CPT-CEF-treated cancer cells. Cell cycle analysis also showed G1 phase arrest, which indicated possible synergistic effects of the nano-carrier. These study results show that CPT-CEF causes a dose-dependent cell viability reduction in HT29 and A549 cells and induces apoptosis in colon cancer cells via caspase-3 activation. These data strongly suggest that CPT could be used as a major nanocarrier for CPT to effectively treat colon cancer.

Phytochemical profiling of Turbinaria ornata and its antioxidant and anti-proliferative effects

Objectives

To analyse the phytochemicals and evaluate the antioxidant and anti-proliferative ability of Turbinaria ornata (Turner) J. Agardh, 1848.

Methods

A phytochemical analysis of the T. ornata-hexane extract (To-HE) and T. ornata-aqueous extract (To-AE) was performed. T. ornata extracts were analysed by gas chromatography-mass spectrometry (GC-MS), Fourier transform infrared spectroscopy (FTIR) and high-performance liquid chromatography (HPLC). The antioxidant properties of To-HE and To-AE were determined by 2,2-diphenyl-1-picrylhydrazyl radical scavenging (DPPH) and ferric ion reducing power (FRAP) assays. In addition, the in vitro anti-proliferative properties of To-HE and To-AE were assessed in kidney epithelial cells from the African green monkey (Vero) and in adenocarcinomic human alveolar basal epithelial cells (A549) using the MTT (3-(4,5-dimethylthiazol- 2yl)-2,5-diphenyltetrazolium bromide, a yellow tetrazole) assay.

Results

The phytochemical screening of T. ornata revealed the presence of saponin, alkaloids, amino acids, fixed oil and fat and phenolic compounds (tannins, flavonoids and total phenol). A higher antioxidant ability was found in To-HE than in To-AE. The anti-proliferative efficacy values (μg/mL) of To-HE and To-AE for A549 and Vero cells were 62.91 and 93.00 and 72.64 and 106.6, respectively. The FTIR analysis revealed the presence of functional groups such as alcohols, amides, aromatics, amines, alkyl halides, alkynes, alkanes and carboxylic acids. The GC-MS analysis of To-HE revealed the presence of 13 active compounds.

Conclusion

Owing to its recorded anti-proliferative effect, further pharmaceutical studies on the development of this anticancer drug are merited.

Goniothalamin induces mitochondria-mediated apoptosis associated with endoplasmic reticulum stress-induced activation of JNK in HeLa cells

Goniothalamin, a natural occurring styryl-lactone isolated from Goniothalamus macrophyllus (Blume) Hook. f. & Thomson var. macrophyllus, can trigger cancer cell death in various types of cancer cell. The present study focused on elucidation of the mitochondria-mediated apoptosis associated with endoplasmic reticulum (ER) stress-induced activation of c-Jun NH₂-terminal kinase (JNK) by goniothalamin in HeLa cervical cancer cells. Cell viability was determined using an MTT assay, and DNA condensation and loss of mitochondrial membrane potential were determined using Hoechst 33342 and JC-1 staining, respectively. Flow cytometry was used for cell cycle and phosphatidyl-serine exposure analyses. Apoptotic-associated ER stress signaling pathways were determined using immunoblotting, reverse transcription-polymerase chain reaction (RT-PCR) and RT-quantitative PCR analyses. The results suggested that goniothalamin suppressed cell proliferation in a time- and dose-dependent manner. The induction of apoptosis was confirmed by increased DNA condensation, loss of mitochondrial membrane potential and cell surface phosphatidyl-serine presentation. The cell cycle analysis demonstrated that the goniothalamin-treated HeLa cells were in G2/M arrest. Determination of the caspase cascade and apoptotic proteins indicated the induction of apoptosis through the intrinsic pathway. In addition, the levels of phosphorylated JNK and the transcription factor, C/EBP homologous protein (CHOP), an ER stress-associated apoptotic molecule, were increased in the goniothalamin-treated cells. These data indicated that goniothalamin exerted a cytotoxic effect against HeLa cells via the induction of mitochondria-mediated apoptosis, associated with ER stress-induced activation of JNK.

Cell cycle arrest and mechanism of apoptosis induction in H400 oral cancer cells in response to Damnacanthal and Nordamnacanthal isolated from Morinda citrifolia

Oral cancer is the eleventh most prevalent cancer worldwide. The most prevalent oral cancer is oral squamous cell carcinoma (OSCC). Damnacanthal (DAM) and nordamnacanthal (NDAM), the anthraquinone compounds, are isolated from the root of Morinda citrifolia L. (Noni), which has been used for the treatment of several chronic diseases including cancer. The objectives of this study were to evaluate the cytotoxicity, cell death mode, cell cycle, and the molecular mechanism of apoptosis induced by DAM and NDAM on OSCC. The cytotoxic effects of these compounds against OSCC cell lines were determined by MTT assay. The cell death mode was analysed by DNA laddering and FITC-annexin V/PI flow cytometric assays. In addition, the mechanism of apoptosis induced by DAM and NDAM was detected using mitochondrial membrane potential, Cytochrome c, and caspases assays. Finally, the effect of DAM and NDAM on cell cycle phase distribution of OSCC cells was detected by flow cytometry. In the present study, DAM and NDAM showed cytotoxicity towards OSCC cell lines and the maximum growth inhibition for both compounds was observed in H400 cells with IC50 value of 1.9 and 6.8 μg/ml, respectively, after 72 h treatment. The results also demonstrated the inhibition of H400 OSCC cells proliferation, internucleosomal cleavage of DNA, activation of intrinsic apoptosis pathway, and cell cycle arrest caused by DAM and NDAM. Therefore, these findings suggest that DAM and NDAM can be potentially used as antitumor agents for oral cancer therapy.

5-Acetyl goniothalamin suppresses proliferation of breast cancer cells via Wnt/β-catenin signaling

Styryl lactones are plant-derived compounds from genus Goniothalamus with promising anti-proliferation and anticancer properties. However, the exact mechanism and the target for their activities remained unclear. In the present study, we investigated the effect of 5-acetyl goniothalamin (5GTN) from Goniothalamus marcanii on Wnt/β-catenin signaling pathway which is a key regulator in controlling cell proliferation in breast cancer cells (MCF-7 and MDA-MB-231). 5GTN, a naturally occurring derivative of goniothalamin (GTN) mediated the toxicity to MCF-7 and MDA-MB-231 cells in a dose- and time- related manner, and was more potent than that of GTN. 5GTN strongly inhibited cell proliferation and markedly suppressed transcriptional activity induced by β-catenin in luciferase reporter gene assay. In consistent with this view, the expression of Wnt/β-catenin signaling target genes including c-Myc, cyclin D1 and Axin2 in MCF-7 and MDA-MB-231 cells were suppressed after treatment with 5GTN. It was concomitant with cell cycle arrest at G₁ phase and cell apoptosis in MCF-7 cells. In addition, 5GTN enhanced glycogen synthase kinase (GSK-3β) activity and therefore reduced the expression of active form of β-catenin protein in MCF-7 and MDA-MB-231 cells. Taken together, 5GTN exhibited a promising anticancer effect against breast cancer cells through an inhibition of Wnt/β-catenin signaling. This pathway may be served as a potential chemotherapeutic target for breast cancer by 5GTN.

Connexin 30 downregulates Insulin-like growth factor receptor-1, abolishes Erk and potentiates effects of an IGF-R inhibitor in a glioma cell line

Connexins (Cx) play a crucial role in cell communication though regulation of cell growth and proliferation. In recent decades, both suppressive and enhancing roles of gap junction proteins in malignancy have been proposed, though mechanisms remain unclear. We intend to evaluate the impact of Cx30 on dysregulated growth of glioma owing to an aberrant expression of Insulin-like growth factor-1 receptor (IGF-1R). The study also examined whether Cx30 expression influenced sensitivity of glioma cells to Picropodophyllin (PPP), the potent inhibitor of IGF-1R. C6 cells transfected with full length Cx30 resulted in complete abolition of colony-forming efficiency. Interestingly, PPP-supplemented cells behaved differently with and without exogenous Cx as confirmed by wound closure assay. The expressions of phosphorylated and unphosphorylated IGF-1R along with its key signaling enzymes, pAkt/pErk, were also varied significantly in transfected and non-transfected C6 cells. pIGF-1R and IGF-1R were significantly reduced on Cx30 transfection when compared with that of non-transfected cells. pErk expression was abolished in transfected C6 with no significant difference in the expression of pAkt. The potency of PPP against C6 was more pronounced in the presence of Cx30. We demonstrate that Cx30 has the potential to alter the IGF-1R mediated pathway thereby influencing the growth, proliferation and migration of glioma cells which could further enhance the effect of therapeutic intervention. Though it could not be corroborated that the observations made are due to Cx30-mediated channel-dependent and/or independent impact, we stress the impact of significance of Cx30 on IGF-1R in glioma and also in therapeutic aspects.

Goniothalamin induces apoptosis associated with autophagy activation through MAPK signaling in SK-BR-3 cells

Goniothalamin, a plant bioactive styrly-lactone, possesses many biological activities. In the present study, the anticancer effect of goniothalamin on human breast cancer cell line SK-BR-3 was investigated. The results showed that goniothalamin induced nuclear condensation, DNA fragmentation, apoptotic bodies and mitochondrial dysfunction as determined by JC-1 staining. Goniothalamin also increased the Bax/Bcl-2 ratio and expression of cleaved caspase-7, cleaved caspase-9 and cleaved PARP, but decreased Bcl-2 expression. In addition, goniothalamin induced apoptosis via p-JNK1/2 and p-p38 upregulation and inhibited cell survival via p-ERK1/2 and p-Akt downregulation. Notably, goniothalamin induced autophagy through upregulation of Atg7, Atg12-Atg5 conjugation and LC3II. The increased p-p38 and p-JNK1/2 and decreased p-Akt may lead to autophagy induction. Therefore, goniothalamin promoted apoptosis associated with autophagy induction in SK-BR-3 cells through p-p38 and p-JNK1/2 upregulation and p-Akt downregulation. The present study indicated that goniothalamin may be further used as a potential therapeutic candidate or may offer an alternative treatment for breast cancer.

Goniothalamin induces cell cycle arrest and apoptosis in H400 human oral squamous cell carcinoma: A caspase-dependent mitochondrial-mediated pathway with downregulation of NF-κβ

Goniothalamin is a natural occurring styryl-lactone compound isolated from Goniothalamus macrophyllus. It had been demonstrated to process promising anticancer activity on various cancer cell lines. However, little study has been carried out on oral cancer. The aim of this study was to determine the cytotoxic effects of goniothalamin against H400 oral cancer cells and its underlying molecular pathways. Results from MTT assay demonstrated that goniothalamin exhibited selective cytotoxicity as well as inhibited cells growth of H400 in dose and time-dependent manner. This was achieved primarily via apoptosis where apoptotic bodies and membrane blebbing were observed using AO/PI and DAPI/Annexin V-FITC fluorescence double staining. In order to understand the apoptosis mechanisms induced by goniothalamin, apoptosis assessment based on mitochondrial membrane potential assay and cytochrome c enzyme-linked immunosorbent assay were carried out. Results demonstrated that the depolarization of mitochondrial transmembrane potential facilitated the release of mitochondrial cytochrome c into cytosol. Caspases assays revealed the activation of initiator caspase-9 and executioner caspase-3/7 in dose-dependent manners. This form of apoptosis was closely associated with the regulation on Bcl-2 family proteins, cell cycle arrest at S phase and inhibition of NF-κβ translocation from cytoplasm to nucleus. Conclusion, goniothalamin has the potential to act as an anticancer agent against human oral squamous cell carcinoma (H400 cells).

Antiproliferative activity of goniothalamin enantiomers involves DNA damage, cell cycle arrest and apoptosis induction in MCF-7 and HB4a cells

(R)-goniothalamin (R-GNT) is a styryl lactone that exhibits antiproliferative property against several tumor cell lines. (S)-goniothalamin (S-GNT) is the synthetic enantiomer of R-GNT, and their biological properties are poorly understood. The aim of this study was to evaluate the antiproliferative mechanisms of (R)-goniothalamin and (S)-goniothalamin in MCF-7 breast cancer cells and HB4a epithelial mammary cells. To determine the mechanisms of cell growth inhibition, we analyzed the ability of R-GNT and S-GNT to induce DNA damage, cell cycle arrest and apoptosis. Moreover, the gene expression of cell cycle components, including cyclin, CDKs and CKIs, as well as of genes involved in apoptosis and the DNA damage response were evaluated. The natural enantiomer R-GNT proved more effective in both cell lines than did the synthetic enantiomer S-GNT, inhibiting cell proliferation via cell cycle arrest and apoptosis induction, likely in response to DNA damage. The cell cycle inhibition caused by R-GNT was mediated through the upregulation of CIP/KIP cyclin-kinase inhibitors and through the downregulation of cyclins and CDKs. S-GNT, in turn, was able to cause G0/G1 cell cycle arrest and DNA damage in MCF-7 cells and apoptosis induction only in HB4a cells. Therefore, goniothalamin presents potent antiproliferative activity to breast cancer cells MCF-7. However, exposure to goniothalamin brings some undesirable effects to non-tumor cells HB4a, including genotoxicity and apoptosis induction.

Upregulation of cyclin-dependent kinase inhibitors CDKN1B and CDKN1C in hepatocellular carcinoma-derived cells via goniothalamin-mediated protein stabilization and epigenetic modifications

Cell cycle deregulation is common in human hepatocellular carcinoma (HCC). To ensure proper cell cycle controlling, cyclin/cyclin-dependent kinases (CDK) complexes are tightly regulated by CDK inhibitors (CKIs) in normal cells. However, insufficient cyclin-dependent kinase inhibitor 1B (CDKN1B, also known as p27^Kip1) and CDKN1C (p57^Kip2) proteins are characteristics of high-risk HCC. In two HCC-derived cell lines with distinct genetic backgrounds, we identified a small natural compound, goniothalamin (GTN), serving as an inducer of CKIs. In TP53-mutated (Y220C) and retinoblastoma 1 (RB1)-positive Huh-7 cells, GTN stabilized CDKN1B protein levels by targeting the degradation of its specific E3 ubiquitin ligase (S-phase kinase-associated protein 2). Alternatively, in TP53- and RB1-negative Hep-3B cells, GTN increased CDKN1C transcription and its subsequent translation by acting as a histone deacetylase inhibitor. In both cell lines, GTN induced G₀/G₁ cell cycle arrest, delayed S phase entry of cells and inhibited anchorage-independent cell growth which might be attributed to the upregulation of CKIs and downregulation of several positive cell cycle regulators, including CDC28 protein kinase regulator subunit 1B, cyclin E1 and D1, cyclin-dependent kinase 2 (CDK2), CDK4, CDK6, E2F transcription factor 1 and/or transcription factor Dp-1. Therefore, GTN might represent a novel class of anticancer drug that induces CKIs through post-translational and epigenetic modifications.

Apoptosis induction in human leukemic promyelocytic HL-60 and monocytic U937 cell lines by goniothalamin

Goniothalamin is an active compound extracted from Goniothalamus griffithii, a local plant found in northern Thailand. Goniothalamin inhibits cancer cell growth but is also toxic to normal cells. The aims of this study were to identify the cytotoxic effect of goniothalamin and the mechanism of cell death in human HL-60 and U937 cells. Cytotoxicity was determined by MTT assay and cell cycle profiles were demonstrated by staining with propidium iodide (PI) and flow cytometry. Apoptosis was confirmed by staining with annexin V-FITC/propidium iodide (PI) and flow cytometry. Reduction of mitochondrial transmembrane potential was determined by staining with dihexyloxacarbocyanine iodide and flow cytometry and expression of Smac, caspase-8 and -9 was demonstrated by Western blotting. Goniothalamin inhibited growth of HL-60 and U937 cell lines. An increase of SubG1 phase was found in their cell cycle profiles, indicating apoptosis as the mode of cell death. Apoptosis was confirmed by the flip-flop of phosphatidylserine using annexin V-FITC/PI assay in HL60 and U937 cells in a dose response manner. Furthermore, reduction of mitochondrial transmembrane potential was found in both cell types while expression of caspase-8, -9 and Smac/Diablo was increased in HL-60 cells. Taken together, our results indicate that goniothalamin-treated human leukemic cells undergo apoptosis via intrinsic and extrinsic pathways.

C5-curcuminoid-4-aminoquinoline based molecular hybrids: design, synthesis and mechanistic investigation of anticancer activity

Novel hybrids exhibiting excellent anticancer activity against most of the NCI 60 cell lines through apoptotic pathways are reported herein.

A green chemistry approach for the synthesis of gold nanoconjugates that induce the inhibition of cancer cell proliferation through induction of oxidative stress and their in vivo toxicity study

The synthesis and fabrication of green chemistry based biocompatible gold nanoparticles could be clinically effective towards cancer therapeutics in the near future.

Emerging anticancer potentials of goniothalamin and its molecular mechanisms

The treatment of most cancers is still inadequate, despite tremendous steady progress in drug discovery and effective prevention. Nature is an attractive source of new therapeutics. Several medicinal plants and their biomarkers have been widely used for the treatment of cancer with less known scientific basis of their functioning. Although a wide array of plant derived active metabolites play a role in the prevention and treatment of cancer, more extensive scientific evaluation of their mechanisms is still required. Styryl-lactones are a group of secondary metabolites ubiquitous in the genus Goniothalamus that have demonstrated to possess antiproliferative activity against cancer cells. A large body of evidence suggests that this activity is associated with the induction of apoptosis in target cells. In an effort to promote further research on the genus Goniothalamus, this review offers a broad analysis of the current knowledge on Goniothalamin (GTN) or 5, 6, dihydro-6-styryl-2-pyronone (C₁₃H₁₂O₂), a natural occurring styryl-lactone. Therefore, it includes (i) the source of GTN and other metabolites; (ii) isolation, purification, and (iii) the molecular mechanisms of actions of GTN, especially the anticancer properties, and summarizes the role of GTN which is crucial for drug design, development, and application in future for well-being of humans.

Roles of plant extracts and constituents in cervical cancer therapy

Cervical cancer is a major health problem worldwide and is the most frequent cause of cancer in women in India. Early detection and affordable drugs with clinical efficacy have to go hand-in-hand in order to comprehensibly address this serious health challenge. Plant-based drugs with potent anticancer effects should add to the efforts to find a cheap drug with limited clinical side effects. Keeping this very purpose in mind, an attempt has been made in this review to explore the potential of plant extracts or constituents known to exhibit antitumorigenic activity or exert cytotoxic effect in human cervical carcinoma cells. Alkaloids such as those isolated from C. vincetoxicum and T. Tanakae, naucleaorals A and B, isolated from the roots of N. orientalis, (6aR)-normecambroline, isolated from the bark of N. dealbata appear promising in different human cervical carcinoma cells with the IC50 of 4.0-8 μg/mL. However, other compounds such as rhinacanthone and neolignans isolated from different plants are not far behind and kill cervical cancer cells at a very low concentrations. Among plant extracts or its constituents that enhance the effect of known anticancer drugs, noni, derived from the plant M. citrifolia perhaps is the best candidate. The cytotoxic potency and apoptotic index of cisplatin was found to significantly enhanced in combination with noni in different human cervical carcinoma cells and it therefore holds significance as promising herbal-based anticancer agent. However, efficacy needs to be further investigated in various cervical cell lines and more importantly, in in vivo cervical cancer models for possible use as an alternative and safe anticancer drug.

Downregulation of Cdk1 and cyclinB1 expression contributes to oridonin-induced cell cycle arrest at G2/M phase and growth inhibition in SGC-7901 gastric cancer cells

BACKGROUND

Oridonin isolated from Rabdosia rubescens, a plant used to treat cancer in Chinese folk medicine, is one of the most important antitumor active ingredients. Previous studies have shown that oridonin has anti- tumor activities in vivo and in vitro, but little is known about cell cycle effects of oridonin in gastric cancer.

MATERIALS AND METHODS

MTT assay was adopted to detect the proliferation inhibition of SGC-7901 cells, the cell cycle was assessed by flow cytometry and protein expression by Western blotting.

RESULTS

Oridonin could inhibit SGC-7901 cell proliferation, the IC50 being 15.6 μM, and blocked SGC-7901 cell cycling in the G2/M phase. The agent also decreased the protein expression of cyclinB1 and CDK1.

CONCLUSIONS

Oridonin may inhibit SGC-7901 growth and block the cells in the G2/M phase by decreasing Cdk1 and cyclinB1 proteins.