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The present study aims to continue the study of corchorusoside C ( 1 ), a cardenolide isolated from Streptocaulon juventas , as a potential anticancer agent. A mechanistic study was pursued in a zebrafish model and in DU-145 prostate cancer cells to investigate the selectivity of 1 towards NF-κB and PARP-1 pathway elements. Compound 1 was found to inhibit the expression of IKKα and NF-κB p65 in TNF-α induced zebrafish and inhibit the expression of NIK in vitro. The protein expression levels of XRCC-1 were increased and p53 decreased in DU-145 cells. XIAP protein expression was initially decreased after treatment with 1 , followed by an increase in expression at doses higher than the IC 50 value. The activity of caspase-1 and the protein expression levels of IL-18 were both decreased following treatment of 1 . The binding interactions for 1 to NIK, XRCC-1, p53, XIAP, and caspase-1 proteins were explored in molecular docking studies. Additionally, the toxicity profile of 1 in zebrafish was favorable in comparison to its analog digoxin and other anticancer drugs at the same MTD in zebrafish. Overall, 1 targets the noncanconical NF-κB pathway in vivo and in vitro, and is well tolerated in zebrafish supporting its potential in the treatment of prostate cancer., Competing Interests: The authors declare that there are no conflict of interest.

Background/aim: Effect of capsicodendrin on the NF-κB pathway was studied in MCF-7 cancer cells., Materials and Methods: The transcription factor assay was used to screen for NF-κB activity. The effect on IKKβ, ICAM-1, and caspase-7 were studied using western blot. Caspase-1 was studied using Promega Caspase-Glo ® assay. Reactive oxygen species (ROS) were detected using the fluorescent probe DCFH-DA. The potentiometric dye JC-1 was used to assess mitochondrial membrane potential (ΔΨm) and the cell cycle was examined using a fluorescence-activated cell sorter., Results: NF-κB p65 inhibitory effect was IC 50 =8.6 μM and cytotoxic activity was IC 50 =7.5 μM. The upstream IKK and the downstream ICAM-1 were down-regulated. Sub G 1 -phase population increased to 81% after 12 h of treatment with capsicodendrin (10 μM) and there was no loss of ΔΨM., Conclusion: Increased levels of intracellular ROS promoted activity of caspase-1 and induced cell death in MCF-7 cells. Capsicodendrin may be a future anticancer agent that prevents the progression of metastatic breast cancer., (Copyright © 2021 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background/aim: This study aimed to uncover the effects of (+)-betulin on the NF-κB-apoptotic pathway in MDA-MB-231 cells, and determine its toxicity and protein expression in vivo., Materials and Methods: Cell cytotoxicity and toxicity were determined using the SRB assay and a zebrafish model, respectively. Western blot, mitochondrial transmembrane potential (MTP), and computational modeling analysis were performed., Results: (+)-betulin inhibited the growth of MDA-MB-231 cells, but did not induce toxicity in zebrafish. (+)-Betulin inhibited the activity of NF-κB p65 in silico and in vitro. In cells, (+)-betulin down-regulated NF-κB p50 and 65, IKKα and β, ICAM-1 and bcl-2 expressions. Cell co-treatment with (+)-betulin and TNFα increased the (+)-betulin cytotoxic potential. Moreover, (+)-betulin induced the loss of MTP. Furthermore, (+)-betulin, in zebrafish, down-regulated the expression of NF-κB p65, IKKα, ΙΚΚβ and procaspase-3., Conclusion: The results contribute to the understanding of the mode of action on apoptosis induction by inhibiting NF-κB pathway in MDA-MB-231 cells., (Copyright © 2020 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Natural products are a valuable source of anticancer agents, with many naturally derived compounds currently used in clinical and preclinical treatments. This study aims to investigate the antiproliferative activity and potential mechanism of action of the xanthoquinodin JBIR-99, isolated from fungi Parengyodontium album MEXU 30,054 and identified by single-crystal X-ray crystallography. Cytotoxicity of xanthoquinodin was evaluated in a panel of human cancer cells lines and CCD-112-CoN normal colon cells, using the sulforhodamine B assay. PC-3 prostate cancer cells were used in biochemical assays including cell cycle, mitochondrial transmembrane potential (MTP), reactive oxygen species (ROS) and caspase activity. Expression levels of apoptosis-pathway-related proteins were analyzed by Western blot. The in vivo toxicity of xanthoquinodin was determined using a zebrafish model. Xanthoquinodin showed cytotoxicity in all cancer cell lines but demonstrated relative selective potency against PC-3 cells with an IC 50 1.7 μM. In CCD-112-CoN cells, xanthoquinodin was non-cytotoxic at 100 μM. In PC-3 cells, the compound induced loss of MTP, production of ROS, and cell cycle arrest in S phase. The expression and activity of caspase-3 was increased, which correlates with the upregulation of Cyt c, Bax, nuclear factor kappa-B (NF-κB) (p65) and IKKβ, and downregulation of poly ADP ribose polymerase (PARP-1) and Bcl-2. Lastly, xanthoquinodin did not cause any visible developmental toxicity in zebrafish at 50 μM. These results demonstrate xanthoquinodin induces apoptosis in PC-3 prostate cancer cells by activation of both intrinsic and extrinsic apoptotic pathways. In addition, the non-toxic effect in vivo indicates that xanthoquinodin could be a useful lead in the development of a novel, anti-cancer agent that is selective for prostate cancer., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Arisaema jacquemontii is traditionally used in treatment of different diseases. In this study, phytochemical, in vitro biological and chemo-preventive screening of A. jacquemontii was carried out to explore its pharmacological potential., Methods: The dried tuber of A. jacquemontii was extracted in 11 organic solvent mixture of different polarity. The extracts were screened for phytochemical assays (phenolics and flavonoids), antioxidants potential (free radical scavenging activity, total antioxidant activity, reducing power), biological activities (antibacterial, antifungal, cytotoxic, antileishmanial, protein kinase inhibition), and chemopreventive activities using different cell lines through standard protocols., Results: Significant amount phenolic contents were determined in EtOH and MeOH extracts (210.3 ± 3.05 and 193.2 ± 3.15 μg GAE/mg, respectively). Maximum flavonoid content was determined in MeOH extract (22.4 ± 4.04 μg QE/mg). Noteworthy, DPPH scavenging activity was also recorded for MeOH extract (87.66%) followed by MeOH+EtOAc extract (85.11%). Considerable antioxidant capacity (7.8 ± 0.12 μg AAE/mg) and reducing power (3.1 ± 0.15 μg AAE/mg) was observed in extract of MeOH. The LC 50 against brine shrimp and leishmanial parasite was found 9.01 and 12.87 μg/mL for n-Hex and CHCl 3 extracts, respectively. The highest zone of inhibition against Streptomyces hyphae formation (12.5 ± 1.77 mm) by n-Hex extract. Growth zone of inhibition 13.8 ± 1.08 mm was recorded for EtOAc and MeOH extracts, respectively against Micrococcus luteus while 10.0 ± 0.11 mm for MeOH extract against Aspergillus flavus. In-vitro cytotoxic assay showed that n-Hex extract had higher cytotoxicity against DU-145 prostate cancer and HL-60 cancer cell lines. NF-kB and MTP potential showed 34.01 and 44.87 μg/mL for n-Hex and CHCl 3 extracts, respectively in chemo-preventive potential., Conclusion: The study concludes that Arisaema jacquemontii bears significant phytochemical activity and pharmacological activities, this plant can be further explored for isolation of active component against a number of aliments.

Background/aim: The survival rate of women diagnosed with triple-negative breast-cancer (TNBC) remains low. Hence, this study aimed at the chemical and biological optimization of furanosteroid derivatives for the treatment of this type of malignancy using TNBC cells., Materials and Methods: Semi-synthetic analogs of wortmannolone ( 1-6 ) that negatively affected the aberrant pathways in tumor cells were evaluated in hormone-independent breast cancer cells using western blot and cell-cycle analysis., Results: Wortmannolone derivatization generated NF-ĸB inhibitors as new lead structures for further development. Compound ( 3 ) was found to be the most significantly active lead., Conclusion: Structure-activity analysis in the present study showed that acetylation of the hydroxyl groups and substitution on C3 and C17 of wortmannolone enhanced biological activity. Alpha-substitution of the acetyl group in C3 on ring A (compound 3 ) resulted in ROS inducing effect; however, presence of an acetyl group in β-position of C3 displayed the highest NF-ĸB p65 inhibitory activity (0.60 μM)., (Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Recent progress is described in an ongoing collaborative multidisciplinary research project directed towards the purification, structural characterization, chemical modification, and biological evaluation of new potential natural product anticancer agents obtained from a diverse group of organisms, comprising tropical plants, aquatic and terrestrial cyanobacteria, and filamentous fungi. Information is provided on how these organisms are collected and processed. The types of bioassays are indicated in which initial extracts, chromatographic fractions, and purified isolated compounds of these acquisitions are tested. Several promising biologically active lead compounds from each major organism class investigated are described, and these may be seen to be representative of a very wide chemical diversity., (Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.)

Background/aim: Dichamanetin is a C-benzylated flavanone isolated as a major secondary metabolite from Piper sarmentosum, a plant used as a spice in Southeast Asia. This study aimed to investigate the path through which dichamanetin exerts its antiproliferative effect., Materials and Methods: The study of several signaling cellular components, namely, reactive oxygen species (ROS) levels, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) transcription factor, mitochondrial membrane potential, DNA binding, poly ADP-ribose polymerase (PARP1) inhibition and proteasome inhibition was performed using an enzyme-linked immunosorbent (ELISA) assay, cell sorting, and western blot., Results: Dichamanetin significantly reduced the cell viability of various types of human cancer cells (HT-29 colon, DU145 prostate, and MDA-MB-231 breast cancer) in a concentration- and time-dependent manner and induced G1 arrest of the cell cycle. It was also demonstrated that the selective cytotoxic effect of dichamanetin in cancer cells is mediated by the induction of oxidative stress., Conclusion: Our findings suggest that dichamanetin isolated from an edible herb has cancer chemotherapeutic potential.

Sphenostylisins A-C (1-3), three complex dimeric compounds representing two novel carbon skeletons, along with an additional eight new compounds, sphenostylisins D-K (4-11), were isolated from the active chloroform-soluble extract of the root bark of Sphenostylis marginata ssp. erecta using a bioactivity-guided isolation approach. The structures were elucidated by means of detailed spectroscopic analysis, including NMR and HRESIMS analysis, and tandem MS fragmentation was utilized to further support the structures of 1-3. The absolute configuration of sphenostylisin C (3) was established by electronic circular dichroism analysis. Plausible biogenetic relationships between the modified isoflavonoids 1-11 are proposed, and a cyclization reaction of 9 was conducted to support one of the biogenetic proposals made. All of these pure isolates were evaluated against a panel of in vitro bioassays, and among the results obtained, sphenostylisin A (1) was found to be a very potent NF-κB inhibitor (IC50 = 6 nM).

Bioactivity-directed fractionation of the organic extracts of two filamentous fungi of the Bionectriaceae, strains MSX 64546 and MSX 59553 from the Mycosynthetix library, led to the isolation of a new dimeric epipolythiodioxopiperazine alkaloid, verticillin H (1), along with six related analogs, Sch 52900 (2), verticillin A (3), gliocladicillin C (4), Sch 52901 (5), 11'-deoxyverticillin A (6) and gliocladicillin A (7). The structures of compounds 1-7 were determined by extensive NMR and HRMS analyses, as well as by comparisons to the literature. All compounds (1-7) were evaluated for cytotoxicity against a panel of human cancer cell lines, displaying IC(50) values ranging from 1.2 μM to 10 nM. Compounds 1-5 were examined for activity in the NF-κB assay, where compounds 2 and 3 revealed activity in the sub-micromolar range. Additionally, compounds 1, 3 and 4 were tested for EGFR inhibition using an enzymatic assay, while compound 3 was examined against an overexpressing EGFR(+ve) cancer cell line.

Aim: (5Z)-7-Oxozeaenol was studied to reveal the path through which it exerts its effects on triple-negative MDA-MB-231 breast cancer cells., Materials and Methods: The apoptotic effect of (5Z)-7-oxozeaenol on MDA-MB-231 cancer cells was analyzed by cell flow cytometry. The effects of (5Z)-7-oxozeaenol on the expression of the nuclear factor kappa B (NF-κB) p65, p50, IκB kinase (IKKα), IKKβ and caspase-7 were analyzed by western blot. The expression of intracellular reactive oxygen species (ROS) and effects on cell adhesion were also assessed. Cell viability was determined using the 3[4,5-dimethylthiazol-2-yl-]2,5-diphenyl tetrazolium bromide (MTT) assay., Results: (5Z)-7-Oxozeaenol down-regulated NF-κB in a dose-dependent manner. Intracellular levels of ROS increased in a dose-dependent manner when treated with (5Z)-7-oxozeaenol and potentiated in the presence of H(2)O(2), when compared to paclitaxel which was used as positive control. Treatment with (5Z)-7-oxozeaenol resulted in G1-phase arrest of treated cells and inhibition of cell proliferation. Cell adhesion was notably affected in treated cells. (5Z)-7-Oxozeaenol also significantly enhanced apoptosis of treated cells, through the activation of caspase-7., Conclusion: Our findings suggest that (5Z)-7-oxozeaenol is a potent up-stream inhibitor of the NF-κB pathway, enhances the sensitivity of treated cells to apoptosis induced by ROS, and affects cell adhesion of MDA-MB-231 breast cancer cells. Thus, (5Z)-7-oxozeaenol is a potential new lead for breast cancer drug development since it might, in combination therapy, enhance the efficacy of current treatments and reduce resistance to chemotherapy of triple negative breast cancer.

Aim: As part of an on going investigation of novel anticancer agents from natural origin, the biological and cellular effects of (5Z)-7-oxozeaenol on cancer cells were investigated., Materials and Methods: The expression of nuclear factor kappa B (NF-κB), IκB kinase (IKKα), IKKβ and caspase-3 were analyzed by western blot. Reactive oxygen species (ROS) fluorescence and caspase luminescent assays were used to assess the intracellular effects in HeLa cervical and HT-29 colon cancer cell lines. The mitochondrial transmembrane potential (MTP) was analyzed by fluorescence-activated cell sorting (FACS)., Results: Cells treated with (5Z)-7-oxozeaenol exhibited down-regulation of NF-κB in a dose-dependent manner. Treatment with (5Z)-7-oxozeaenol significantly enhanced the levels of ROS in HeLa and HT-29 cells. MTP was reduced in HT-29 cells. The expression of caspase-3 and -7 was induced in (5Z)-7-oxozeaenol treated HeLa cells, in comparison with those treated with paclitaxel., Conclusion: Our findings suggest that (5Z)-7-oxozeaenol is a potent inhibitor of the NF-κB pathway and potentiates the production of ROS, as well as induces caspase-3 and -7 in HeLa and HT-29 cancer cells. Thus, (5Z)-7-oxozeaenol represents a new lead compound for drug development, particularly as a new cancer chemotherapeutic agent, since programmed cell death might be mediated through the activation of a caspase-arbitrated pathway.

Two new xanthone-anthraquinone heterodimers, acremoxanthone C (5) and acremoxanthone D (2), have been isolated from an extract of an unidentified fungus of the order Hypocreales (MSX 17022) by bioactivity-directed fractionation as part of a search for anticancer leads from filamentous fungi. Two known related compounds, acremonidin A (4) and acremonidin C (3) were also isolated, as was a known benzophenone, moniliphenone (1). The structures of these isolates were determined via extensive use of spectroscopic and spectrometric tools in conjunction with comparisons to the literature. All compounds (1-5) were evaluated against a suite of biological assays, including those for cytotoxicity, inhibition of the 20S proteasome, mitochondrial transmembrane potential and nuclear factor-κB.

Aims: The aim of this study was to describe quantitatively the potential demethylating effects of the plant-derived compound isoliquritigenin (ILTG) on the death-associated protein kinase-1 (DAPK1) promoter region of colon cancer and leukemia cell lines., Methods: Methylation-specific real-time polymerase chain reaction-melting curve analysis (MSP-MCA) was the primary method used. A simple cytotoxicity assay and an ethidium bromide displacement assay were used to evaluate the chemopreventive indices and account for any problems in fluorometric assessment caused by intercalating potential of the compound of interest., Results: ILTG was able to affect the melting curve significantly when using MSP-MCA. ILTG exhibited a demethylating activity on HT-29 colon cancer and HL-60 leukemia cells., Conclusion: ILTG found in licorice (Glycyrrhiza glabra) may have the potential for being a cancer chemopreventive agent. From the specific assays performed in this experiment, ILTG appears to possess potential for development as a demethylating agent for either colon cancer or leukemia cancer prevention.

Aim: Brucea javanica was studied to identify nuclear factor kappaB (NF-κB) inhibitors exhibiting reactive oxygen species (ROS) intracellular amplification., Material and Methods: Eight compounds were evaluated for selective cytotoxicity using HT-29, HeLa, and HL-60 cells, and in a NF-κB assay. Active compounds were then tested using ROS and mitochondria transmembrane potential (MTP) assays. NF-κB and nuclear factor activated T-cell (NFAT) translocation were also assessed using their respective whole cell assays., Results: Bruceajavanone B, bruceantin, bruceine A, (-)-hydnocarpin, and chrysoeriol exhibited cytotoxic potential and NF-κB p65 inhibition. Chrysoeriol exhibited selective cytotoxicity against leukemia cells with greater potency and also showed an ability to up-regulate NFAT transcriptional pathways through the amplification of intracellular ROS, in the presence of H2O2, to a greater degree than bruceantin and bruceine., Conclusion: Chrysoeriol selectively kills leukemic cells and potentiates the amplification of ROS levels. Therefore, chrysoeriol could serve as a potential chemotherapeutic modifier for leukemia chemotherapy since leukemia cells have a higher susceptibility to elevated ROS levels.

A collaborative multidisciplinary research project is described in which new natural product anticancer drug leads are obtained from a diverse group of organisms, constituted by tropical plants, aquatic cyanobacteria, and filamentous fungi. Information is provided on how these organisms are collected and processed. The types of bioassays are indicated in which crude extracts of these acquisitions are tested. Progress made in the isolation of lead bioactive secondary metabolites from three tropical plants is discussed.