Reactive oxygen species mediate isoalantolactone-induced apoptosis in human prostate cancer cells

Sesquiterpene lactones as emerging biomolecules to cease cancer by targeting apoptosis

Apoptosis is a programmed cell death comprising two signaling cascades including the intrinsic and extrinsic pathways. This process has been shown to be involved in the therapy response of different cancer types, making it an effective target for treating cancer. Cancer has been considered a challenging issue in global health. Cancer cells possess six biological characteristics during their developmental process known as cancer hallmarks. Hallmarks of cancer include continuous growth signals, unlimited proliferation, resistance to proliferation inhibitors, apoptosis escaping, active angiogenesis, and metastasis. Sesquiterpene lactones are one of the large and diverse groups of planet-derived phytochemicals that can be used as sources for a variety of drugs. Some sesquiterpene lactones possess many biological activities such as anti-inflammatory, anti-viral, anti-microbial, anti-malarial, anticancer, anti-diabetic, and analgesic. This review article briefly overviews the intrinsic and extrinsic pathways of apoptosis and the interactions between the modulators of both pathways. Also, the present review summarizes the potential effects of sesquiterpene lactones on different modulators of the intrinsic and extrinsic pathways of apoptosis in a variety of cancer cell lines and animal models. The main purpose of the present review is to give a clear picture of the current knowledge about the pro-apoptotic effects of sesquiterpene lactones on various cancers to provide future direction in cancer therapeutics.

Synthesis, Cytotoxic, and Computational Screening of Some Novel Indole-1,2,4-Triazole-Based S-Alkylated N-Aryl Acetamides

Molecular hybridization has emerged as the prime and most significant approach for the development of novel anticancer chemotherapeutic agents for combating cancer. In this pursuit, a novel series of indole-1,2,4-triazol-based N-phenyl acetamide structural motifs 8a-f were synthesized and screened against the in vitro hepatocellular cancer Hep-G2 cell line. The MTT assay was applied to determine the anti-proliferative potential of novel indole-triazole compounds 8a-f, which displayed cytotoxicity potential as cell viabilities at 100 µg/mL concentration, by using ellipticine and doxorubicin as standard reference drugs. The remarkable prominent bioactive structural hybrids 8a, 8c, and 8f demonstrated good-to-excellent anti-Hep-G2 cancer chemotherapeutic potential, with a cell viability of (11.72 ± 0.53), (18.92 ± 1.48), and (12.93 ± 0.55), respectively. The excellent cytotoxicity efficacy against the liver cancer cell line Hep-G2 was displayed by the 3,4-dichloro moiety containing indole-triazole scaffold 8b, which had the lowest cell viability (10.99 ± 0.59) compared with the standard drug ellipticine (cell viability = 11.5 ± 0.55) but displayed comparable potency in comparison with the standard drug doxorubicin (cell viability = 10.8 ± 0.41). The structure-activity relationship (SAR) of indole-triazoles 8a-f revealed that the 3,4-dichlorophenyl-based indole-triazole structural hybrid 8b displayed excellent anti-Hep-G2 cancer chemotherapeutic efficacy. The in silico approaches such as molecular docking scores, molecular dynamic simulation stability data, DFT, ADMET studies, and in vitro pharmacological profile clearly indicated that indole-triazole scaffold 8b could be the lead anti-Hep-G2 liver cancer therapeutic agent and a promising anti-Hep-G2 drug candidate for further clinical evaluations.

Dankasterone A induces prostate cancer cell death by inducing oxidative stress

Oxidative stress plays a dual role in tumor survival, either promoting tumor development or killing tumor cells under different conditions. Dankasterone A is a secondary metabolite derived from the fungus Talaromyces purpurogenu. It showed good potential in a screen for anti-prostate cancer compounds. In this study, MTT results showed dankasterone A was cytotoxic to prostate cancer cells, with an IC50 of 5.10 μM for PC-3 cells and 3.41 μM for 22Rv1 cells. Further studies, plate cloning assays and real-time cell analysis monitoring showed that dankasterone A significantly inhibited clonal colony formation and cell migration in 22Rv1 and PC-3 cells. In addition, flow cytometry results showed that dankasterone A induced apoptosis in prostate cancer cells while having no impact on cell cycle distribution. At the molecular level, Protein microarray experiments and western blot assays revealed that dankasterone A specifically and dramatically upregulated HO-1 protein expression; and the results of cell fluorescence staining showed that dankasterone A induced overexpression of reactive oxygen species in 22Rv1 and PC-3 cells. Taken together, dankasterone A induced prostate cancer cells to undergo intense oxidative stress, which resulted in the production of large amounts of HO-1 and the release of large amounts of reactive oxygen species, leading to apoptosis of prostate cancer cells, ultimately resulting in the inhibition of both cell proliferation and migration. We also validated the anti-prostate cancer effects of dankasterone A in vivo in a zebrafish xenograft tumor model. In conclusion, dankasterone A has the potential to be developed as an anti-prostate cancer drug.

Isoalantolactone mediates the degradation of BCR-ABL protein in imatinib-resistant CML cells by down-regulating survivin

Isoalantolactone (Iso) is a bioactive lactone isolated from the root of Inula helenium L, which has been reported to have many pharmacological effects. To investigate the role and mechanism of isoalantolactone in chronic myeloid leukemia (CML), we first investigated isoalantolactone's anti-proliferative effects on imatinib-sensitive and imatinib-resistant CML cells by CCK8. Flow cytometry was used to detect isoalantolactone-induced cell apoptosis. Survivin was overexpressed in KBM5 and KBM5T315I cells using the lentivirus vector pSIN-3×flag-PURO. In KBM5 and KBM5T315I cells, shRNA was used to knockdown survivin. Cellular Thermal Shift Assay (CETSA) was used to detect the interaction between isoalantolactone and survivin. The ubiquitin of survivin induced by isoalantolactone was detected through immunoprecipitation. Quantitative polymerase-chain reaction (Q-PCR) and western blotting were used to detect the levels of mRNA and protein. Isoalantolactone inhibits the proliferation and promotes apoptosis of imatinib-resistant CML cells. Although isoalantolactone inhibits the proteins of BCR-ABL and survivin, it cannot inhibit survivin and BCR-ABL mRNA levels. Simultaneously, it was shown that isoalantolactone can degrade survivin protein by increasing ubiquitination. It was demonstrated that isoalantolactone-induced survivin mediated downregulation of BCR-ABL protein. It was also revealed that isoalantolactone triggered BCR-ABL protein degradation via caspase-3. Altogether, isoalantolactone inhibits survivin through the ubiquitin proteasome pathway, and mediates BCR-ABL downregulation in a caspase-3 dependent manner. These data suggest that isoalantolactone is a natural compound, which can be used as a potential drug to treat TKI-resistant CML.

Dual regulation of Akt and glutathione caused by isoalantolactone effectively triggers human ovarian cancer cell apoptosis

<p indent="0mm">Ovarian cancer is one of leading causes of cancer death in gynecological tumor. Isoalantolactone (IL), present in several medicinal plants, exhibits various biological activities, and its mechanism underlying anti-ovarian cancer activity needs to be further investigated. Here, we find that IL inhibits the proliferation of SKOV-3 and OVCAR-3 cells by causing G2/M phase arrest and inducing apoptosis. Moreover, IL decreases intracellular glutathione (GSH) level, and induces reactive oxygen species (ROS) generation in SKOV-3 cells. Furthermore, IL induces inactivation of Akt which is required for the cytotoxicity of IL. In addition, overexpression of Akt attenuates the IL-induced growth inhibition and ROS generation. GSH supplementation moderately increases the expression of phospho-Akt. Further investigation reveals that pretreatment with L-buthionine-sulfoximine (a GSH biosynthesis inhibitor) restores the Akt-mediated attenuation of growth inhibition induced by IL. Moreover, co-treatment with IL and wortmannin (an Akt pathway inhibitor) increases the growth inhibition attenuated by pretreatment with N-acetyl-L-cysteine (a precursor for GSH biosynthesis). These results indicate that inactivation of Akt and downregulation of GSH level induced by IL are related to each other. In conclusion, combined targeting Akt and GSH is an effective strategy for cancer therapy and IL can be a promising anticancer agent for further exploration.</p>.

Molecular mechanisms behind ROS regulation in cancer: A balancing act between augmented tumorigenesis and cell apoptosis

ROS include hydroxyl radicals (HO^.), superoxide (O₂^..), and hydrogen peroxide (H₂O₂). ROS are typically produced under physiological conditions and play crucial roles in living organisms. It is known that ROS, which are created spontaneously by cells through aerobic metabolism in mitochondria, can have either a beneficial or detrimental influence on biological systems. Moderate levels of ROS can cause oxidative damage to proteins, DNA and lipids, which can aid in the pathogenesis of many disorders, including cancer. However, excessive concentrations of ROS can initiate programmed cell death in cancer. Presently, a variety of chemotherapeutic drugs and herbal agents are being investigated to induce ROS-mediated cell death in cancer. Therefore, preserving ROS homeostasis is essential for ensuring normal cell development and survival. On account of a significant association of ROS levels at various concentrations with carcinogenesis in a number of malignancies, further studies are needed to determine the underlying molecular mechanisms and develop the possibilities for intervening in these processes.

Repositioning of acefylline as anti-cancer drug: Synthesis, anticancer and computational studies of azomethines derived from acefylline tethered 4-amino-3-mercapto-1,2,4-triazole

Novel azomethines derived from acefylline tethered triazole hybrids (7a-k) have been synthesized and evaluated against human liver cancer cell line (Hep G2) using MTT assay. The synthesized series of azomethines exhibited promising efficacy against liver cancer cell line. Screening of the synthesized series identified compound 7d with the least cell viability value (11.71 ± 0.39%) as the most potent anticancer agent in contrast to the reference drug acefylline (cell viability = 80 ± 3.87%). In this study, the potentials of the novel agents (7a-k) to inhibit liver cancer proteins were assessed. Subsequently, the structure-activity relationship of the potential drug candidates was assessed via ADME/T molecular screening. The cytotoxic potential of these derivatives was also investigated by hemolysis and thrombolysis. Their hemolytic and thrombolytic studies showed that all of these drugs had very low cytotoxicity and moderate clot lysis activity. Compound 7g (0.26% hemolysis) and 7k (52.1% clot lysis) were the least toxic and moderate thrombolytic agents respectively.

Ultrasound-Assisted Synthesis and In Silico Modeling of Methanesulfonyl-Piperazine-Based Dithiocarbamates as Potential Anticancer, Thrombolytic, and Hemolytic Structural Motifs

Piperazine-based dithiocarbamates serve as important scaffolds for numerous pharmacologically active drugs. The current study investigates the design and synthesis of a series of dithiocarbamates with a piperazine unit as well as their biological activities. Under ultrasound conditions, the corresponding piperazine-1-carbodithioates 5a–5j were synthesized from monosubstituted piperazine 2 and N-phenylacetamides 4a–4j in the presence of sodium acetate and carbon disulfide in methanol. The structures of the newly synthesized piperazines were confirmed, and their anti-lung carcinoma effects were evaluated. A cytotoxic assay was performed to assess the hemolytic and thrombolytic potential of the synthesized piperazines 5a–5j. The types of substituents on the aryl ring were found to affect the anticancer activity of piperazines 5a–5j. Piperazines containing 2-chlorophenyl (5b; cell viability = 25.11 ± 2.49) and 2,4-dimethylphenyl (5i; cell viability = 25.31 ± 3.62) moieties demonstrated the most potent antiproliferative activity. On the other hand, piperazines containing 3,4-dichlorophenyl (5d; 0.1%) and 3,4-dimethylphenyl (5j; 0.1%) rings demonstrated the least cytotoxicity. The piperazine with the 2,5-dimethoxyphenyl moiety (5h; 60.2%) showed the best thrombolytic effect. To determine the mode of binding, in silico modeling of the most potent piperazine (i.e., 5b) was performed, and the results were in accordance with those of antiproliferation. It exhibits a similar binding affinity to PQ10 and an efficient conformational alignment with the lipophilic site of PDE10A conserved for PQ10A.

Isoalantolactone Induces Cell Cycle Arrest, Apoptosis and Autophagy in Colorectal Cancer Cells

Colorectal cancer (CRC) is an aggressive cancer. Isoalantolactone (IATL) has been reported to exert cytotoxicity against various cancer cells, but not CRC. In this study, we explored the anti-CRC effects and mechanism of action of IATL in vitro and in vivo. Our results demonstrated that IATL inhibited proliferation by inducing G0/G1 phase cell cycle arrest, apoptosis and autophagy in CRC cells. Repression of autophagy with autophagy inhibitors chloroquine (CQ) and Bafilomycin A1 (Baf-A1) enhanced the anti-CRC effects of IATL, suggesting that IATL induces cytoprotective autophagy in CRC cells. Mechanistic studies revealed that IATL lowered protein levels of phospho-AKT (Ser473), phospho-mTOR (Ser2448), phospho-70S6K (Thr421/Ser424) in CRC cells. Inhibition of AKT and mTOR activities using LY294002 and rapamycin, respectively, potentiated the inductive effects of IATL on autophagy and cell death. In vivo studies showed that IATL suppressed HCT116 tumor growth without affecting the body weight of mice. In consistent with the in vitro results, IATL lowered protein levels of Bcl-2, Bcl-XL, phospho-AKT (Ser473), phospho-mTOR (Ser2448), and phsopho-70S6K (Thr421/Ser424), whereas upregulated protein levels of cleaved-PARP and LC3B-II in HCT116 tumors. Collectively, our results demonstrated that in addition to inhibiting proliferation, inducing G0/G1-phase cell cycle arrest and apoptosis, IATL initiates cytoprotective autophagy in CRC cells by inhibiting the AKT/mTOR signaling pathway. These findings provide an experimental basis for the evaluation of IATL as a novel medication for CRC treatment.

Exploring the Synergistic Anticancer Potential of Benzofuran-Oxadiazoles and Triazoles: Improved Ultrasound- and Microwave-Assisted Synthesis, Molecular Docking, Hemolytic, Thrombolytic and Anticancer Evaluation of Furan-Based Molecules

Ultrasound- and microwave-assisted green synthetic strategies were applied to furnish benzofuran–oxadiazole 5a–g and benzofuran–triazole 7a–h derivatives in good to excellent yields (60–96%), in comparison with conventional methods (36–80% yield). These synthesized derivatives were screened for hemolysis, thrombolysis and anticancer therapeutic potential against an A549 lung cancer cell line using an MTT assay. Derivatives 7b (0.1%) and 5e (0.5%) showed the least toxicity against RBCs. Hybrid 7f showed excellent thrombolysis activity (61.4%) when compared against reference ABTS. The highest anticancer activity was displayed by the 5d structural hybridwith cell viability 27.49 ± 1.90 and IC₅₀ 6.3 ± 0.7 μM values, which were considerably lower than the reference drug crizotinib (IC₅₀ 8.54 ± 0.84 μM). Conformational analysis revealed the spatial arrangement of compound 5d, which demonstrated its significant potency in comparison with crizotinib; therefore, scaffold 5d would be a promising anticancer agent on the basis of cytotoxicity studies, as well as in silico modeling studies.

Natural Products as the Modulators of Oxidative Stress: An Herbal Approach in the Management of Prostate Cancer

Prostate cancer is the most commonly diagnosed and frequently occurred cancer in the males globally. The current treatment strategies available to treat prostate cancer are not much effective and express various adverse effects. Hence, there is an urgent need to identify novel treatment that can improve patient outcome. From times immemorial, natural products are highly recognized for novel drug development for various diseases including cancer. Cancer cells generally maintain higher basal levels of reactive oxygen species (ROS) when compared to normal cells due to its high metabolic rate. However, initiation of excess intracellular ROS production can not be tolerated by the cancer cells and induce several cell death signals which are in contrast to normal cells. Therefore, small molecules of natural origin that induce ROS can potentially kill cancer cells in specific and provide a better opportunity to develop a novel drug therapy. In this review, we elaborated various classes of medicinal compounds and their mechanism of killing prostate cancer cells through direct or indirect ROS generation. This can generate a novel thought to develop promising drug candidate to treat prostate cancer patients.

Synthesis, Hemolytic Studies, and In Silico Modeling of Novel Acefylline-1,2,4-Triazole Hybrids as Potential Anti-cancer Agents against MCF-7 and A549

A series of novel theophylline-7-acetic acid (acefylline)-derived 1,2,4-triazole hybrids with N-phenyl acetamide moieties (11a-j) have been synthesized and tested for their inhibitory (in vitro) potential against two cancer cell lines, A549 (lung) and MCF-7 (breast), using MTT assay. Among these derivatives, 11a, 11c, 11d, 11g, and 11h displayed remarkable activity against both cancer cell lines having cell viability values in the 21.74 ± 1.60-55.37 ± 4.60% range compared to acefylline (86.32 ± 1.75%) using 100 μg/μL concentration of compounds. These compounds were further screened against the A549 cancer cell line (lung) to find their half-maximal inhibitory concentration (IC₅₀) by applying various concentrations of these compounds. Compound 11g (2-(5-((1,3-dimethyl-2,6-dioxo-2,3-dihydro-1H-purin-7(6H)-yl)methyl)-4-phenyl-4H-1,2,4-triazol-3-ylthio)-N-p-tolylacetamide) with the least IC₅₀ value (1.25 ± 1.36 μM) was discerned as a strong inhibitor of cancer cell multiplication in both cell lines (A549 and MCF-7). Their hemolytic studies revealed that all of them had very low cytotoxicity. Finally, in silico modeling was carried out to find the mode of binding of the highly active compound (11g), which was according to the results of anti-cancer activity.

Jaceosidin: A Natural Flavone with Versatile Pharmacological and Biological Activities

Nature always remains an inexhaustible source of treasures for mankind. It remains a mystery for every challenge until the completion of the challenge. While we talk about the complicated health issues, nature offers us a great variety of chemical scaffolds and their various moieties packed in the form of natural products e.g., plants, microorganisms (fungi, algae, protozoa), and terrestrial vertebrates and invertebrates. This review article is an update about jaceosidin, a bioactive flavone, from genus Artemisia. This potentially active compound exhibits a variety of pharmacological activities including anti-inflammatory, anti-oxidant, anti-bacterial, antiallergic and anti-cancer activities. The bioactivities and the therapeutic action of jaceosidin, especially the modulation of different cell signaling pathways (ERK1/2, NF-κB, PI3K/Akt and ATM-Chk1/2) which become deregulated in various pathological disorders, have been focused here. The reported data suggest that the bioavailability of this anti-cancer compound should be enhanced by utilizing various chemical, biological and computational techniques. Moreover, it is recommended that researchers and scientists should work on exploring the mode of action of this particular flavone to precede it further as a potent anti-cancer compound.

11, 13-Dehydro Lactone Moiety in Gynecologic Cancer Cells

Background:

To study the anti-cancer effect of isoalantolactone, a sesquiterpene lactoneisolated from the roots of Inula heleniumon human gynecologic cancer cells.

Methods:

A structure-activity relationship experiment was designed to identify the functional moiety of isoalantolactone for its significant anti-cancer activity. Five gynecologic cancer cell lines were treated with isoalantolactone. Cell proliferation was determined by MTT assay in vitro and cell apoptosis by flow cytometry.

Results:

We found isoalantolactone strongly inhibited the cell proliferationofHEC-1, HAC-2, HOC-21, and HeLa cells. Its inhibitory effect was comparable to that of well-known chemotherapeutic agents, cisplatin and taxol. Furthermore, isoalantolactone induced apoptosis in HeLa cells via caspase. On the contrary, its 11, 13-dihydro derivatives had much weaker anti-proliferative activities than the parent compound.

Conclusion:

Isoalantolactone exhibited strong anti-proliferative activities and apoptosis-inducing effects on gynecologic cancer cells. The 11, 13-dehydro lactone moiety was critical for its anti-proliferative activity.

Biochanin A: A novel bioactive multifunctional compound from nature

Natural products (NPs) will continue to serve humans as matchless source of novel drug leads and an inspiration for the synthesis of non-natural drugs. As our scientific understanding of 'nature' is rapidly expanding, it would be worthwhile to illuminate the pharmacological distinctions of NPs to the scientific community and the public. Flavonoids have long fascinated scientists with their remarkable structural diversity as well as biological functions. Consequently, this review aims to shed light on the sources and pharmacological significance of a dietary isoflavone, biochanin A, which has been recently emerged as a multitargeted and multifunctional guardian of human health. Biochanin A possesses anti-inflammatory, anticancer, neuroprotective, antioxidant, anti-microbial, and hepatoprotective properties. It combats cancer development by inducing apoptosis, inhibition of metastasis and arresting cell cycle via targeting several deregulated signaling pathways of cancer. It fights inflammation by blocking the expression and activity of pro-inflammatory cytokines via modulation of NF-κB and MAPKs. Biochanin A acts as a neuroprotective agent by inhibiting microglial activation and apoptosis of neurons. As biochanin A has potential to modulate several biological networks, thus, it can be anticipated that this therapeutically potent compound might serve as a novel lead for drug development in the near future.

Molecular Insight into the Therapeutic Promise of Flavonoids against Alzheimer's Disease

Alzheimer’s disease (AD) is one of the utmost chronic neurodegenerative disorders, which is characterized from a neuropathological point of view by the aggregates of amyloid beta (Aβ) peptides that are deposited as senile plaques and tau proteins which form neurofibrillary tangles (NFTs). Even though advancement has been observed in order to understand AD pathogenesis, currently available therapeutic methods can only deliver modest symptomatic relief. Interestingly, naturally occurring dietary flavonoids have gained substantial attention due to their antioxidative, anti-inflammatory, and anti-amyloidogenic properties as alternative candidates for AD therapy. Experimental proof provides support to the idea that some flavonoids might protect AD by interfering with the production and aggregation of Aβ peptides and/or decreasing the aggregation of tau. Flavonoids have the ability to promote clearance of Aβ peptides and inhibit tau phosphorylation by the mTOR/autophagy signaling pathway. Moreover, due to their cholinesterase inhibitory potential, flavonoids can represent promising symptomatic anti-Alzheimer agents. Several processes have been suggested for the aptitude of flavonoids to slow down the advancement or to avert the onset of Alzheimer’s pathogenesis. To enhance cognitive performance and to prevent the onset and progress of AD, the interaction of flavonoids with various signaling pathways is proposed to exert their therapeutic potential. Therefore, this review elaborates on the probable therapeutic approaches of flavonoids aimed at averting or slowing the progression of the AD pathogenesis.

Isoalantolactone restores the sensitivity of gram-negative Enterobacteriaceae carrying MCR-1 to carbapenems

Polymyxin B has been re‐applied to the clinic as the final choice for the treatment of multidrug‐resistant gram‐negative pathogenic infections, but the use of polymyxin B has been re‐assessed because of the emergence and spread of the plasmid‐mediated mcr‐1 gene. The purpose of this study was to search for an MCR inhibitor synergistically acting with polymyxin to treat the infection caused by this pathogen. In this study, we used the broth microdilution checkerboard method to evaluate the synergistic effect of isoalantolactone (IAL) and polymyxin B on mcr‐1‐positive Enterobacteriaceae. Growth curve analysis, time‐killing assays and a combined disc test were used to further verify the efficacy of the combined drug. Colonization of the thigh muscle in mice, survival experiments and lung tissue section observations was used to determine the effect of synergy in vivo after Klebsiella pneumoniae and Escherichia coli infection. We screened a natural compound, IAL, which can enhance the sensitivity of polymyxin B to mcr‐1‐positive Enterobacteriaceae. The results showed that the combined use of polymyxin B and IAL has a synergistic effect on mcr‐1‐positive Enterobacteriaceae, such as K pneumoniae and E coli, not only in vitro but also in vivo. Our results indicate that IAL is a natural compound with broad application prospects that can prolong the service life of polymyxin B and make outstanding contributions to the treatment of gram‐negative Enterobacteriaceae infections resistant to polymyxin B.

Ophiopogonin D' induces RIPK1‑dependent necroptosis in androgen‑dependent LNCaP prostate cancer cells

Ophiopogonin D' (OPD') is a natural compound extracted from Ophiopogon japonicus, which is a plant used in traditional Chinese medicine. Our previous study has indicated that OPD' exhibits antitumor activity against androgen-independent prostate cancer (PCa), but the effects and the underlying molecular mechanism of action of OPD' in androgen-dependent PCa were unclear. In the present study, OPD' induced significant necroptosis in androgen-dependent LNCaP cancer cells by activating receptor-interacting serine/threonine-protein kinase 1 (RIPK1). Exposure to OPD' also increased Fas ligand (FasL)-dependent RIPK1 protein expression. The OPD'-induced necroptosis was inhibited by a RIPK1 inhibitor necrostatin-1, further supporting a role for RIPK1 in the effects of OPD´. The antitumor effects of OPD' were also inhibited by a mixed lineage kinase domain-like protein (MLKL) inhibitor necrosulfonamide. Following treatment with inhibitors of RIPK1 and MLKL, the effects of OPD' on LNCaP cells were inhibited in an additive manner. In addition, co-immunoprecipitation assays demonstrated that OPD' induced RIPK3 upregulation, leading to the assembly of a RIPK3-MLKL complex, which was independent of RIPK1. Furthermore, OPD' increased the expression of Fas-associated death domain, which is required to induce necroptosis in LNCaP cells. OPD' also regulated the expression levels of FasL, androgen receptor and prostate-specific antigen in a RIPK1-dependent manner. These results suggested that OPD' may exhibit potential as an anti-PCa agent by inducing RIPK1- and MLKL-dependent necroptosis.

Putative Roles of Plant-Derived Tannins in Neurodegenerative and Neuropsychiatry Disorders: An Updated Review

Neurodegenerative and neuropsychiatric diseases are characterized by the structural and functional abnormalities of neurons in certain regions of the brain. These abnormalities, which can result in progressive neuronal degeneration and functional disability, are incurable to date. Although comprehensive efforts have been made to figure out effective therapies against these diseases, partial success has been achieved and complete functional recovery is still not a reality. At present, plants and plant-derived compounds are getting more attention because of a plethora of pharmacological properties, and they are proving to be a better and safer target as therapeutic interventions. This review aims to highlight the roles of tannins, 'the polyphenol phytochemicals', in tackling neurodegenerative diseases including Alzheimer's and Parkinson's diseases as well as neuropsychiatric disorders like depression. Among the multifarious pharmacological properties of tannins, anti-oxidative, anti-inflammatory, and anti-cholinesterase activities are emphasized more in terms of neuroprotection. The current review also throws light on mechanistic pathways by which various classes of tannins execute neuroprotective effects. Despite their beneficial properties, some harmful effects of tannins have also been elaborated.

Curcumol: From Plant Roots to Cancer Roots

Natural products, an infinite treasure of bioactive scaffolds, have provided an excellent reservoir for the discovery of drugs since millennium. These naturally occurring, biologically active and therapeutically effective chemical entities have emerged as novel paradigm for the prevention of various diseases. This review aims to give an update on the sources as well as pharmacological profile of curcumol, a pharmacologically active sesquiterpenoid, which is an imperative bioactive constituent of several plants mainly from genus Curcuma. Curcumol has potential to fight against cancer, oxidative stress, neurodegeneration, microbial infections, and inflammation. Curcumol has been documented as potent inducer of apoptosis in numerous cancer cells via targeting key signaling pathways as MAPK/ERK, PI3K/Akt and NF-κB which are generally deregulated in several cancers. The reported data reveals multitarget activity of curcumol in cancer treatment suggesting its importance as anticancer drug in future. It is speculated that curcumol may provide an excellent opportunity for the cure of cancer but further investigations on mechanism of its action and preclinical trials are still mandatory to further validate the potential of this natural cancer killer in anticancer therapies.

Isoalantolactone induces apoptosis through ROS-mediated ER stress and inhibition of STAT3 in prostate cancer cells

Background

Prostate cancer is one of the most commonly diagnosed cancers in men worldwide. Currently available therapies for metastatic prostate cancer are only marginally effective. Therefore, new therapeutic agents are urgently needed to improve patient outcome. Isoalantolactone (IATL), an active sesquiterpene naturally present in many vegetables and medicinal plants, is known to induce cell death and apoptosis in various cancer cell lines. Nevertheless, antitumor mechanisms initiated by IATL in cancer cells have not been fully defined.

Methods

Cell apoptosis and cellular ROS levels were analyzed by flow cytometry. Western blot and qRT-PCR were used to analyze the protein and mRNA levels of indicated molecules, respectively. Nude mice xenograft model was used to test the effects of IATL on prostate cancer cell growth in vivo.

Results

In this study, we found that IATL dose-dependently inhibited cancer cell growth and induced apoptosis in PC-3 and DU145 cells. Mechanistically, our data found that IATL induced reactive oxygen species (ROS) production, resulting in the activation of endoplasmic reticulum stress pathway and eventually cell apoptosis in prostate cancer cells. IATL also decreased the protein expression levels of p-STAT3 and STAT3, and the effects of IATL were reversed by pretreatment with N-acetyl-L-cysteine (NAC). In vivo, we found that IATL inhibited the growth of prostate cancer xenografts without exhibiting toxicity. Treatment of mice bearing human prostate cancer xenografts with IATL was also associated with induction of ER stress and inhibtion of STAT3.

Conclusion

In summary, our results unveil a previously unrecognized mechanism underlying the biological activity of IATL, and provide a novel anti-cancer candidate for the treatment of prostate cancer.

Alantolactone induces apoptosis and suppresses migration in MCF‑7 human breast cancer cells via the p38 MAPK, NF‑κB and Nrf2 signaling pathways

Human breast cancer is a malignant type of cancer with high prevalence. In the present study, the anticancer effects of alantolactone, a sesquiterpene lactone, on the human breast cancer cell line MCF‑7 were investigated in vitro. The MCF‑7 cell morphology changed from diamond to round subsequent to treatment with alantolactone, and the cell viability reduced significantly compared with that of the control cells. Alantolactone induced apoptosis of MCF‑7 cells by regulating the protein expression levels of B‑cell lymphoma 2 (Bcl‑2), Bcl‑2‑associated X protein, p53, caspase‑3 and caspase‑12, which are associated with the apoptotic pathway, and suppressed colony formation and migration by regulating the protein expression of matrix metalloproteinase (MMP)‑2, MMP‑7 and MMP‑9. Cell signaling pathway analysis confirmed that alantolactone increased the phosphorylation of p38, and decreased the nuclear expression levels of p65 and nuclear factor erythroid 2‑related factor 2 (Nrf2), suggesting that the apoptosis‑promoting and migration‑suppressing effect of alantolactone may partially depend on regulating the p38 MAPK, NF‑κB and Nrf2 pathways. These results also suggested that alantolactone may become a potential therapeutic strategy for treating breast cancer.

Tubeimoside-1, Triterpenoid Saponin, as a Potential Natural Cancer Killer

Nature, an expert craftsman of molecules, has generated extensive array of bioactive molecular entities. It persists as an inexhaustible resource for discovery of drugs and supplied enormous scaffold diversification for development into effectual drugs to treat multiple pathological conditions. This review provides an update on the sources, biological, and pharmacological effects of nature's gift, a triterpenoid saponin, tubeimoside-1 which is a major bioactive constituent of the bulb of Bolbostemma paniculatum. Tubeimoside-1 is known to possess various pharmacological properties such as anti-cancer, anti-HIV, and anti-inflammatory. Recently, anti-proliferative potential of tubeimoside-1 has been widely studied. The present review article seeks to cover the recent developments of tubeimoside-1′s pharmacological position in the arena of herbal drugs, providing an insight into its current status in therapeutic pursuits. This anti-cancer triterpenoid saponin fight cancer progression by induction of apoptosis, cell cycle arrest, and inhibiting metastasis by specifically targeting multiple signaling pathways those are usually deregulated in various cancers. The reported data recommend tubeimoside-1′s mutitarget activity in preference to single effect that may perform an imperative role towards developing tubeimoside-1 into potential pharmacological drug.

Role of Plant-Derived Flavonoids and Their Mechanism in Attenuation of Alzheimer's and Parkinson's Diseases: An Update of Recent Data

Neurodegeneration is a progressive loss of neuronal cells in certain regions of the brain. Most of the neurodegenerative disorders (NDDs) share the communal characteristic such as damage or reduction of various cell types typically including astrocytes and microglial activity. Several compounds are being trialed to treat NDDs but they possess solitary symptomatic advantages along with copious side effects. The finding of more enthralling and captivating compounds to suspend and standstill the pathology of NDDs will be considered as a hallmark of present times. Phytochemicals possess the potential to alternate the synthetic line of therapy against NDDs. The present review explores the potential efficacy of plant-derived flavonoids against most common NDDs including Alzheimer's disease (AD) and Parkinson's disease (PD). Flavonoids are biologically active phytochemicals which possess potential pharmacological effects, including antiviral, anti-allergic, antiplatelet, anti-inflammatory, anti-tumor, anti-apoptotic and anti-oxidant effects and are able to attenuate the pathology of various NDDs through down-regulating the nitric oxide (NO) production, by reducing the tumor necrosis factor-α (TNF-α), by reducing the excitotoxicity of superoxide as well as acting as tyrosine kinase (TK) and monoamine oxidase (MAO) inhibiting enzyme.

Polygodial analog induces apoptosis in LNCaP prostate cancer cells

Prostate cancer (PCa) is the second leading cause of death in American men. The chemotherapeutic treatment strategies are generally not effective and can lead to side effects. Hence, there is an urgent need to identify novel chemotherapeutic agents. The aim of this study was to synthesize and evaluate the therapeutic effects of a synthetic analog of polygodial (PG), a pungent constituent abundantly present in mountain pepper, water pepper and dorrigo pepper, on LNCaP PCa cell line and its anti-cancer mechanisms in a preclinical study. We evaluated the anti-cancer potential of the PG analog namely DRP-27 using various assays such as cell viability by MTT assay, anchorage independent growth by soft agar assay, reactive oxygen species generation by 2',7'-dichlorofluorescein probe-based fluorescence assay, and apoptosis by Annexin-V and TUNEL assays respectively. Western blot analysis was performed to identify the molecular mechanism of DRP-27-induced cell death. Our results showed that DRP-27 significantly inhibited LNCaP cell proliferation in a dose-dependent manner at 48 h treatment in vitro. In addition, DRP-27 potently inhibited anchorage-independent growth of these cells. Flow cytometry, Annexin-V and TUNEL assays confirmed that DRP-27 induces apoptosis in LNCaP cells. DRP-27 also induced the activation of intracellular reactive oxygen species. Western blot analysis revealed that DRP-27 downregulated the expression of survivin, while activating Bax and DNA damage marker pH₂AX in LNCaP cells. In conclusion, our study suggests that DRP-27 might be an effective anti-cancer agent for PCa.

Major terpenoids from Telekia speciosa flowers and their cytotoxic activity in vitro

In addition to known constituents of Telekia speciosa, an acetone extract from ray florets of the plant yielded: 5,5'-dibutoxy-2,2'-bifuran (1), 5,5'-diisobutoxy-2,2'-bifuran (2), α-tocopherol (3), β-tocopherol (4), loliolide palmitate (5), a mixture of calenduladiol esters - 16β-hydroxylupeol-3-O-palmitate (7) and 16β-hydroxylupeol-3-O-myristate (8), 1-epiinuviscolide (12), inuviscolide (13), 3-epiisotelekin (16), 4α-hydroxy-9β,10β-epoxy-1β(H)-11(13)-guaien-8α,12-olide (17), 4α-hydroxy-1β(H)-9(10),11(13)-guaiadien-8α,12-olide (18), loliolide (19) and 4β,10β-dihydroxy-1α(H),5α(H)-11(13)-guaien-8α,12-olide (20). Calenduladiol esters and asperilin (14) were the major constituents of the extract. Their cytotoxic effect on human normal prostate epithelial cells (PNT-2), human prostate carcinoma cell lines, human skin fibroblasts (HSF) and human melanoma cell lines was examined in vitro. Triterpene esters showed no cytotoxicity against nearly all cell lines tested, except for Du145 prostate carcinoma cells (IC₅₀ - 62.0 μΜ). Asperilin displayed activity against the cell lines under study, especially against three tested lines of melanomas (A375, IC₅₀ - 17.6 μΜ, WM793, IC₅₀ - 28.2 μΜ and Hs 294T, IC₅₀ - 29.5 μΜ).

Metabolism Analysis of Alantolactone and Isoalantolactone in Rats by Oral Administration

Alantolactone and isoalantolactone are the major active ingredients of Inulae Radix. Their metabolism in vivo and in vitro was investigated by UPLC-Q-TOF-MS for the first time. As a result, nine metabolites in vivo including cysteine conjugates, oxidates, dehydrogenates, and hydrates were detected in rat bile after oral administration. The metabolites produced in vitro by incubation with rat liver microsomes were found to be substantially identical to those detected in vivo. However, no metabolites were detected in the samples of plasma, feces, and urine or in the incubates of gastric juice, intestinal juice, and intestinal bacteria. These results reveal that the liver is the main metabolic organ for alantolactone and isoalantolactone, and the first pass effect of the liver appears to be the reason for the low oral bioavailability of the two lactones.

Isoalantolactone induces intrinsic apoptosis through p53 signaling pathway in human lung squamous carcinoma cells

Isoalantolactone has recently been revealed to induce apoptosis in several types of cancer. However, little is reported on its anti-tumor potential on human lung cancer. Our present study was designed to investigate its effects on human lung squamous carcinoma SK-MES-1 cells. We found that Isoalantolactone induced cellular and DNA morphological changes and decreased the viability of SK-MES-1 cells. It significantly inhibited the growth of SK-MES-1 cells through apoptosis in a dose-dependent manner via activation of p53. It also induced cell cycle arrest at G1 phase. It can down-regulate Bcl-2 and up-regulate Bax, to induce dissipation of mitochondrial membrane potential and generation of reactive oxygen species. Caspase-3 was also activated by Isoalantolactone, with the cleavage of poly (ADP-ribose) polymerase. Our results reveal that Isoalantolactone induces intrinsic apoptosis in SK-MES-1 cells through p53 signaling pathway, which suggests that Isoalantolactone could be a potential leading compound for future development of anti-lung cancer drugs.

Isoalantolactone inhibits LPS-induced inflammation via NF-κB inactivation in peritoneal macrophages and improves survival in sepsis

Sepsis, a clinical syndrome occurring in patients following infection or injury, is a leading cause of mortality worldwide. It involves uncontrolled inflammatory response resulting in multi-organ failure and even death. Isoalantolactone (IAL), a sesquiterpene lactone, is known for its anti-cancer effects. Nevertheless, little is known about the anti-inflammatory effects of IAL, and the role of IAL in sepsis is unclear. In this study, we demonstrated that IAL decreased lipopolysaccharide (LPS)-mediated production of nitric oxide, PEG₂ and cytokines (IL-6, TNF-α) in peritoneal macrophages and RAW 264.7 macrophages. Moreover, molecular mechanism studies indicated that IAL plays an anti-inflammatory role by inhibiting LPS-induced activation of NF-κB pathway in peritoneal macrophages. In vivo, IAL reduced the secretion of IL-6 and TNF-α in serum, and increased the survival rate of mice with LPS-induced sepsis. In addition, IAL attenuated the activation of NF-κB pathway in liver. Taken together, our data suggest that IAL may represent a potentially new drug candidate for the treatment of sepsis.

Coptisine-induced cell cycle arrest at G2/M phase and reactive oxygen species-dependent mitochondria-mediated apoptosis in non-small-cell lung cancer A549 cells

This study aimed to explore the effect of coptisine on non-small-cell lung cancer and its mechanism through various in vitro cellular models (A549). Results claimed significant inhibition of proliferation by coptisine against A549, H460, and H2170 cells with IC₅₀ values of 18.09, 29.50, and 21.60 µM, respectively. Also, coptisine exhibited upregulation of pH2AX, cell cycle arrest at G2/M phase, and downregulation of the expression of cyclin B1, cdc2, and cdc25C and upregulation of p21 dose dependently. Furthermore, induction of apoptosis in A549 cells by coptisine was characterized by the activation of caspase 9, caspase 8, and caspase 3, and cleavage of poly adenosine diphosphate ribose polymerase. In addition, coptisine was found to increase reactive oxygen species generation, upregulate Bax/Bcl-2 ratio, disrupt mitochondrial membrane potential, and cause cytochrome c release into the cytosol. Besides, treatment with a reactive oxygen species inhibitor (N-acetyl cysteine) abrogated coptisine-induced growth inhibition, apoptosis, reactive oxygen species generation, and mitochondrial dysfunction. Thus, the mediation of reactive oxygen species in the apoptosis-induced effect of coptisine in A549 cells was corroborated. These findings have offered new insights into the effect and mechanisms of action of coptisine against non-small-cell lung cancer.

Altholactone Inhibits NF-κB and STAT3 Activation and Induces Reactive Oxygen Species-Mediated Apoptosis in Prostate Cancer DU145 Cells

Altholactone, a natural compound isolated from Goniothalamus spp., has demonstrated anti-inflammatory and anticancer activities, but its molecular mechanisms are still not fully defined. Nuclear factor kappa B (NF-κB) and signal transducer and activator of transcription 3 (STAT3) play pivotal roles in the cell survival of many human tumors. The objective of this study was to elucidate the mechanism of action of altholactone against prostate cancer DU145 cells and to evaluate whether its effects are mediated by inhibition of NF-κB and STAT3 activity. Altholactone inhibited proliferation of DU145 cells and induced cell cycle arrest in S phase and triggered apoptosis. Reporter assays revealed that altholactone repressed p65- and TNF-α-enhanced NF-κB transcriptional activity and also inhibited both constitutive and IL-6-induced transcriptional activity of STAT3. Consistent with this, altholactone down-regulated phosphorylation of STAT3 and moreover, decreased constitutively active mutant of STAT3 (STAT3C)-induced transcriptional activity. Altholactone treatment also results in down-regulation of STAT3 target genes such as survivin, and Bcl-2 followed by up regulation of pro-apoptotic Bax protein. However, pre-treatment with the antioxidant N-acetylcysteine (NAC) significantly inhibited the activation of Bax and prevented down-regulation of STAT3 target genes. Collectively, our findings suggest that altholactone induces DU145 cells death through inhibition of NF-κB and STAT3 activity.

Vitamin K4 inhibits the proliferation and induces apoptosis of U2OS osteosarcoma cells via mitochondrial dysfunction

Vitamin K (VK) is a group of fat‑soluble vitamins, which serve important roles in blood coagulation and bone metabolism. A recent study reported that several VK subtypes possess antitumor properties, however the antitumor effects of VK in osteosarcoma are unknown. The present study aimed to identify the antitumor effects of VK in osteosarcoma and the possible underlying mechanism of action. The effect of VK4 on cell viability was determined using a 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyltetrazolium bromide (MTT) assay. Cellular and nuclear morphological changes were observed by phase contrast microscopy. Cell cycle analysis, apoptotic rate, mitochondrial membrane potential and levels of reactive oxygen species (ROS) were detected by flow cytometry. In vitro cancer cell migration activities were evaluated using a Wound healing assay and Transwell microplates. The results demonstrated that VK4 arrested the cells in S phase and induced apoptosis. Additional mechanistic studies indicated that the induction of apoptosis by VK4 was associated with the increased production of reactive oxygen species, dissipation of the mitochondrial membrane potential, decreased Bcl‑2 family protein expression levels and activation of caspase‑3. In conclusion, the results suggest that the sensitivity of U2OS osteosarcoma cells to VK4 may be as a result of mitochondrial dysfunction. As it is readily available for human consumption, VK4 may therefore present a novel therapeutic candidate for the treatment of patients with osteosarcoma.

Isoalantolactone inhibits the migration and invasion of human breast cancer MDA-MB-231 cells via suppression of the p38 MAPK/NF-κB signaling pathway

Isoalantolactone is a bioactive sesquiterpene lactone isolated from the flowering plant Inula helenium L. This study was conducted to assess the anti-migratory and anti-invasive activities of isoalantolactone in MDA-MB-231 cells, and to explore the underlying mechanisms. Wound-healing and Transwell chambers assays demonstrated that isoalantolactone inhibited the adhesion, migration and invasion of MDA-MB-231 cells. The activity and expression of MMP-2 and MMP-9 were downregulated by isoalantolactone in a dose-dependent manner. Additionally, isoalantolactone markedly decreased the p-p38 MAPK level, whereas no significant change in p-ERK1/2 and p-JNK1/2 was noted. The downregulation of MMP-2 and MMP-9 protein expression and suppression of in vitro invasion might be associated with the blockade of p38 MAPK activation. Furthermore, isoalantolactone blocked the translocation of NF-κB p65 from the cytoplasm into the nucleus. These results revealed that isoalantolactone inhibited the adhesion, migration and invasion of MDA-MB-231 cells via suppression of the p38 MAPK/NF-κB signaling pathway, and isoalantolactone might be an alternative treatment for breast cancer.

Cytotoxicity of withasteroids: withametelin induces cell cycle arrest at G2/M phase and mitochondria-mediated apoptosis in non-small cell lung cancer A549 cells

Considerable interest has been gained by withasteroids because of their structural uniqueness and wide spectrum of biological activities. However, limited systematic studies for proving their cytotoxic potential have so far been reported. Hence, an attempt was made to test the cytotoxicity of six withasteroids viz., withametelin (WM), withaphysalin D, withaphysalin E, 12-deoxywithastramonolide, Withaperuvin B, and physalolactone against A549, HT-29, and MDA-MB-231 cancer cell lines. Significant cytotoxic effect of WM against A549 cells (IC₅₀ value of 6.0 μM), MDA-MB-231 cells (IC₅₀ value of 7.6 μM), and HT-29 cells (IC₅₀ value of 8.2 μM) was observed. Withaperuvin B and physalolactone were found to be effective against MDA-MB-231 cells. The significantly active WM arrested the A549 cells at G2/M phase and downregulated the expression of G2/M regulatory proteins such as cdc2, cyclin B1, and cdc25C. Apoptosis induced by WM in A549 cells was associated with the generation of ROS and depletion of MMP. Furthermore, WM treatment resulted in Bax upregulation, Bcl-2 downregulation, translocation of cytochrome c to mitochondria, activation of caspase-9 and -3, and PARP cleavage corroborating the apoptosis induction through intrinsic apoptotic pathway. Thus, WM possessing broader cytotoxic effect is a promising lead molecule which has the potential to be developed as a new therapeutic agent for NSCLC.

Diallyl trisulfide induces osteosarcoma cell apoptosis through reactive oxygen species-mediated downregulation of the PI3K/Akt pathway

Diallyl trisulfide (DATS) is a natural organosulfur compound isolated from garlic, and has been reported to possess anticancer activities. However, the cancer growth inhibitory effects and molecular mechanisms in human osteosarcoma cells have not been well studied. The present study demonstrated that DATS significantly reduced cell viability in a dose- and time-dependent manner in MG63 and MNNG/HOS cells. DATS-induced G0/G1 phase arrest was found to correlate with a decrease in cyclin D1 in concomitance with an increase in p21 and p27. DATS induced a marked increase in reactive oxygen species (ROS) levels and collapse of mitochondrial membrane potential (Δψm) in the osteosarcoma cells. DATS induced apoptosis in the MG63 and MNNG/HOS cells via inhibition of the PI3K/Akt signaling pathway and through the mitochondrial apoptotic pathway. The efficiency of DATS basically approached the efficacy of LY294002, a specific PI3K inhibitor. However, N-acetylcysteine (NAC), a general ROS scavenger, completely blocked the DATS-induced ROS increase, inhibition of the PI3K/Akt pathway and cell apoptosis. Overall, DATS has the potential to be developed as a new anticancer drug. The mechanisms of action involve the ROS-mediated downregulation of the PI3K/Akt pathway.

Lycorine induces programmed necrosis in the multiple myeloma cell line ARH-77

Lycorine, a natural alkaloid, has been widely reported to possess potential efficacy against cancer. However, the anti-multiple myeloma mechanism of lycorine is not fully understood. In this study, the results demonstrated that lycorine is effective against multiple myeloma cell line ARH-77 via inducing programmed necrosis. The mechanisms of lycorine on the multiple myeloma cell line ARH-77 are associated with G1 phase cell cycle arrest, mitochondrial dysfunction, reactive oxygen species (ROS) generation, ATP depletion, and DNA damage. Our results elucidate the new mechanism of lycorine against multiple myeloma.

Targeting apoptosis pathways in cancer and perspectives with natural compounds from mother nature

Although the incidences are increasing day after day, scientists and researchers taken individually or by research group are trying to fight against cancer by several ways and also by different approaches and techniques. Sesquiterpenes, flavonoids, alkaloids, diterpenoids, and polyphenolic represent a large and diverse group of naturally occurring compounds found in a variety of fruits, vegetables, and medicinal plants with various anticancer properties. In this review, our aim is to give our perspective on the current status of the natural compounds belonging to these groups and discuss their natural sources, their anticancer activity, their molecular targets, and their mechanism of actions with specific emphasis on apoptosis pathways, which may help the further design and conduct of preclinical and clinical trials. Unlike pharmaceutical drugs, the selected natural compounds induce apoptosis by targeting multiple cellular signaling pathways including transcription factors, growth factors, tumor cell survival factors, inflammatory cytokines, protein kinases, and angiogenesis that are frequently deregulated in cancers and suggest that their simultaneous targeting by these compounds could result in efficacious and selective killing of cancer cells. This review suggests that they provide a novel opportunity for treatment of cancer, but clinical trials are still required to further validate them in cancer chemotherapy.

Antitumor effect of fructose 1,6-bisphosphate and its mechanism in hepatocellular carcinoma cells

We aimed to investigate the antitumor effect and mechanism of fructose 1,6-bisphosphate (F1,6BP) in a hepatocellular carcinoma cell line. HepG2 cells were treated with different concentrations of F1,6BP alone or in combination with antioxidant N-acetyl-L-cysteine (NAC) or catalase (CAT), and cell proliferation assays were performed. Nuclear morphology was observed by fluorescence microscopy after Hoechst staining, and apoptosis was measured with flow cytometry. Changes in reactive oxygen species (ROS) levels in HepG2 cells were detected by 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) staining. A colorimetric assay was adopted to determine the percentage of oxidized glutathione in these cells. CAT and glutathione peroxidase (GSH-Px) mRNA expression levels in HepG2 cells were measured by real-time fluorescence quantitative PCR. HepG2 cell proliferation was significantly inhibited by F1,6BP, accompanied by an increase in intracellular ROS levels and oxidized glutathione. Upregulated apoptosis and characteristic nuclear morphological changes were observed, and the expression of CAT and GSH-Px mRNA was increased after F1,6BP treatment. The antitumor effect of F1,6BP was significantly decreased after pretreatment with NAC and CAT in HepG2 cells. In conclusion, F1,6BP can induce the apoptosis of HepG2 cells. The mechanism involved may be associated with the generation of ROS, especially the production of H2O2.