Curcumin Induces Small Cell Lung Cancer NCI-H446 Cell Apoptosis via the Reactive Oxygen Species-Mediated Mitochondrial Pathway and Not the Cell Death Receptor Pathway

Curcumin suppressed the proliferation and apoptosis of HPV-positive cervical cancer cells by directly targeting the E6 protein

Most human papillomavirus (HPV) types, including HPV16 and HPV18, are closely related to the occurrence of cervical cancer, predominantly through the action of viral oncoproteins E6 and E7. Curcumin, the active ingredient of the turmeric plant, has been gaining attention over the past two decades as an antioxidant, anti-inflammatory, and anticancer agent. In the present study, the HPV-positive cervical cancer cells HeLa and CaSki were treated with curcumin, and the results showed that curcumin has a dose-dependent and time-dependent inhibitory effect on cell viability. In addition, apoptosis induction was further quantitatively confirmed through flow cytometric analysis. Furthermore, the influence of different concentrations of curcumin on the mitochondrial membrane potential was evaluated through JC-1 staining and found to dramatically decrease the membrane potential in treated HeLa and CaSki cells, suggesting the critical role of the mitochondrial pathway in their apoptosis-inducing effect. This study also demonstrated the wound-healing potential of curcumin, and the results of transwell assays showed that curcumin treatment inhibited HeLa and CaSki cell invasion and migration in a dose-dependent manner compared with the control treatment. Curcumin also downregulated the expression of Bcl-2, N-cadherin, and Vimentin and upregulated the expression of Bax, C-caspase-3, and E-cadherin in both cell lines. Further research showed that curcumin also selectively inhibited the expression of the viral oncoproteins E6 and E7, as demonstrated by western blot analysis; moreover, the downregulation of E6 was more significant than that of E7. Our research also showed that coculture with cells infected with siE6 lentivirus (siE6 cells) can inhibit the proliferation, invasion, and metastasis of HPV-positive cells. While the siE6 cells were also treated with curcumin, the effect of curcumin monotherapy was offset. In summary, our research shows that curcumin regulates the apoptosis, migration, and invasion of cervical cancer cells, and the mechanism may be related to its ability to downregulate E6. This study provides a foundation for future research on the prevention and treatment of cervical cancer.

Humanistic Health Management and Cancer: Associations of Psychology, Nutrition, and Exercise with Cancer Progression and Pathogenesis

The incidence rate of cancer is increasing year by year due to the aging of the population, unhealthy living, and eating habits. At present, surgery and medication are still the main treatments for cancer, without paying attention to the impact of individual differences in health management on cancer. However, increasing evidence suggests that individual psychological status, dietary habits, and exercise frequency are closely related to the risk and prognosis of cancer. The reminder to humanity is that the medical concept of the unified treatment plan is insufficient in cancer treatment, and a personalized treatment plan may become a breakthrough point. On this basis, the concept of "Humanistic Health Management" (HHM) is proposed. This concept is a healthcare plan that focuses on self-health management, providing an accurate and comprehensive evaluation of individual lifestyle habits, psychology, and health status, and developing personalized and targeted comprehensive cancer prevention and treatment plans. This review will provide a detailed explanation of the relationship between psychological status, dietary, and exercise habits, and the regulatory mechanisms of cancer. Intended to emphasize the importance of HHM concept in cancer prevention and better prognostic efficacy, providing new ideas for the new generation of cancer treatment.

Curcumin piperidone derivatives induce caspase-dependent apoptosis and suppress miRNA-21 expression in LN-18 human glioblastoma cells

BACKGROUND

Previously, we have reported on the two curcuminoid analogues with piperidone derivatives, namely FLDP-5 and FLDP-8 have more potent anti-proliferative and anti-migration effects than curcumin. In this study, we further investigated the mode of cell death and the mechanism involved in the cell death process induced by these analogues on human glioblastoma LN-18 cells.

RESULTS

The FLDP-5 and FLDP-8 curcuminoid analogues induced LN-18 cell death through apoptosis in a concentration-dependent manner following 24 h of treatment. These analogues induced apoptosis in LN-18 cells through significant loss of mitochondrial mass and mitochondrial membrane potential (MMP) as early as 1-hour of treatment. Interestingly, N-acetyl-l-cysteine (NAC) pretreatment did not abolish the apoptosis induced by these analogues, further confirming the cell death process is independent of ROS. However, the apoptosis induced by the analogues is caspases-dependent, whereby pan-caspase pretreatment inhibited the curcuminoid analogues-induced apoptosis. The apoptotic cell death progressed with the activation of both caspase-8 and caspase-9, which eventually led to the activation of caspase-3, as confirmed by immunoblotting. Moreover, the existing over-expression of miRNA-21 in LN-18 cells was suppressed following treatment with both analogues, which suggested the down-regulation of the miRNA-21 facilitates the cell death process.

CONCLUSION

The FLDP-5 and FLDP-8 curcuminoid analogues downregulate the miRNA-21 expression and induce extrinsic and intrinsic apoptotic pathways in LN-18 cells.

Himalayan flora: targeting various molecular pathways in lung cancer

The fatal amplification of lung cancer across the globe and the limitations of current treatment strategies emphasize the necessity for substitute therapeutics. The incorporation of phyto-derived components in chemo treatment holds promise in addressing those challenges. Despite the significant progressions in lung cancer therapeutics, the complexities of molecular mechanism and pathways underlying this disease remain inadequately understood, necessitating novel biomarker targeting. The Himalayas, abundant in diverse plant varieties with established chemotherapeutic potential, presents a promising avenue for investigating potential cures for lung carcinoma. The vast diversity of phytocompounds herein can be explored for targeting the disease. This review delves into the multifaceted targets of lung cancer and explores the established phytochemicals with their specific molecular targets. It emphasizes comprehending the intricate pathways that govern effective therapeutic interventions for lung cancer. Through this exploration of Himalayan flora, this review seeks to illuminate potential breakthroughs in lung cancer management using natural compounds. The amalgamation of Himalayan plant-derived compounds with cautiously designed combined therapeutic approaches such as nanocarrier-mediated drug delivery and synergistic therapy offers an opportunity to redefine the boundaries of lung cancer treatment by reducing the drug resistance and side effects and enabling an effective targeted delivery of drugs. Furthermore, additional studies are obligatory to understand the possible derivation of natural compounds used in current lung cancer treatment from plant species within the Himalayan region.

Basic research on curcumin in cervical cancer: Progress and perspectives

Curcumin is a polyphenolic substance extracted from plants such as Curcuma longa, Curcuma zedoaria, and radix curcumae, and it has attracted much attention because of the anti-inflammatory, antioxidant, anti-tumor, antibacterial and other multiple pharmacological effects. Cervical cancer is one of the most common malignant tumors in women. With the application of HPV (human papillomavirus) vaccine, the incidence of cervical cancer is expected to be reduced, but it remains difficult to promote the vaccine among low-income population. As a commonly used food additive, curcumin has recently been found to have a significant therapeutic effect in the treatment of cervical cancer. In recent years, numerous in vitro and in vivo studies have found that curcumin can have significant efficacy in anti-cervical cancer treatment by promoting apoptosis, inhibiting tumour cell proliferation, metastasis and invasion, inhibiting HPV and inducing autophagy in tumour cells. However, due to poor water solubility, rapid catabolism, and low bioavailability of curcumin, studies on curcumin derivatives and novel formulations are increasing. Curcumin has a wide range of mechanisms of action against cervical cancer and may become a novel antitumor drug in the future, opening up new ideas for the research of curcumin in the field of antitumor. There is a lack of systematic reviews on the mechanism of action of curcumin against cervical cancer. Therefore, this study is a review of the literature based on the mechanism of action of curcumin against cervical cancer, with a view to providing reference information for scientific and clinical practitioners.

Holistic immunomodulation for small cell lung cancer

Small cell lung cancer (SCLC) is characterized by a high mortality rate, rapid growth, and early metastasis, which lead to a poor prognosis. Moreover, limited clinical treatment options further lower the survival rate of patients. Therefore, novel technology and agents are urgently required to enhance clinical efficacy. In this review, from a holistic perspective, we summarized the therapeutic targets, agents and strategies with the most potential for treating SCLC, including chimeric antigen receptor (CAR) T therapy, immunomodulating antibodies, traditional Chinese medicines (TCMs), and the microbiota, which have been found recently to improve the clinical outcomes and prognosis of SCLC. Multiomics technologies can be integrated to develop effective diagnostic methods and identify new targets for new drug discovery in SCLC. We discussed in depth the feasibility, potential, and challenges of these new strategies, as well as their combinational treatments, which may provide promising alternatives for enhancing the clinical efficacy of SCLC in the future.

Molecular mechanism of Pulmonary diseases caused by exposure to urban PM2.5 in Chengdu-Chongqing Economic Circle, China

Chengdu-Chongqing Economic Circle (CD-CQ Economic Circle) is one of China's four major economic circles and five major urban agglomerations located in Southwest China's Sichuan Basin. The CD-CQ Economic Circle, with its strong economic development and dense population, suffers from severe PM_2.5 pollution, which is known to cause chronic and acute respiratory ailments. This study examined the lung disease-related hub genes, functions, and pathways that are affected by PM_2.5 in summer and winter in the two central megacities of Chengdu and Chongqing. PM_2.5 frequently activates lung disease-associated hub genes, most notably the transcription factor TP53. TP53 interacts with the majority of lung disease-related genes and regulates important and commonly occurring biological functions and pathways, including gland development, aging, reactive oxygen species metabolic process, the response to oxygen levels, and fluid shear stress, among others. Thus, PM_2.5 has been shown to target TP53 for regulating lung disease genes/functions/pathways, thereby influencing the occurrence and progression of lung illnesses. Notably, PM_2.5 may be associated with small cell carcinoma of the lung due to the high number of lung disease genes, hub genes, critical functions, and pathways enriched in this kind of cancer. These findings shed fresh light on the molecular pathophysiology of PM_2.5 pollution on the respiratory system in the CD-CQ Economic Circle and aid in the development of novel techniques for mitigating PM_2.5 pollution-associated respiratory illness.

An mTOR and DNA-PK dual inhibitor CC-115 hinders non-small cell lung cancer cell growth

Molecularly-targeted agents are still urgently needed for better non-small cell lung cancer (NSCLC) therapy. CC-115 is a potent DNA-dependent protein kinase (DNA-PK) and mammalian target of rapamycin (mTOR) dual blocker. We evaluated its activity in different human NSCLC cells. In various primary human NSCLC cells and A549 cells, CC-115 potently inhibited viability, cell proliferation, cell cycle progression, and hindered cell migration/invasion. Apoptosis was provoked in CC-115-stimulated NSCLC cells. The dual inhibitor, however, was unable to induce significant cytotoxic and pro-apoptotic activity in the lung epithelial cells. In primary NSCLC cells, CC-115 blocked activation of mTORC1/2 and DNA-PK. Yet, CC-115-induced primary NSCLC cell death was more potent than combined inhibition of DNA-PK plus mTOR. Further studies found that CC-115 provoked robust oxidative injury in primary NSCLC cells, which appeared independent of mTOR-DNA-PK dual blockage. In vivo studies showed that CC-115 oral administration in nude mice remarkably suppressed primary NSCLC cell xenograft growth. In CC-115-treated NSCLC xenograft tissues, mTOR-DNA-PK dual inhibition and oxidative injury were detected. Together, CC-115 potently inhibits NSCLC cell growth.

Retraction: Structural characterization of centipede oligopeptides and capability detection in human small cell lung carcinoma: inducing apoptosis

Retraction of ‘Structural characterization of centipede oligopeptides and capability detection in human small cell lung carcinoma: inducing apoptosis’ by JingQuan Zhao et al., RSC Adv., 2019, 9, 10927–10936, https://doi.org/10.1039/C8RA09018A.

Protective Effect of Curcumin against Doxazosin- and Carvedilol-Induced Oxidative Stress in HepG2 Cells

Doxazosin and carvedilol have been evaluated as an alternative treatment against chronic liver lesions and for their possible role during the regeneration of damage caused by liver fibrosis in a hamster model. However, these drugs have been reported to induce morphological changes in hepatocytes, affecting the recovery of liver parenchyma. The effects of these α/𝛽 adrenoblockers on the viability of hepatocytes are unknown. Herein, we demonstrate the protective effect of curcumin against the possible side effects of doxazosin and carvedilol, drugs with proven antifibrotic activity. After pretreatment with 1 μM curcumin for 1 h, HepG2 cells were exposed to 0.1–25 μM doxazosin or carvedilol for 24, 48, and 72 h. Cell viability was assessed using the MTT assay and SYTOX green staining. Morphological changes were detected using the hematoxylin and eosin (H&E) staining and scanning electron microscopy (SEM). An expression of apoptotic and oxidative stress markers was analyzed using reverse transcription-quantitative PCR (RT-qPCR). The results indicate that doxazosin decreases cell viability in a time- and dose-dependent manner, whereas carvedilol increases cell proliferation; however, curcumin increases or maintains cell viability. SEM and H&E staining provided evidence that doxazosin and carvedilol induced morphological changes in HepG2 cells, and curcumin protected against these effects, maintaining the morphology in 90% of treated cells. Furthermore, curcumin positively regulated the expression of Nrf2, HO-1, and SOD1 mRNAs in cells treated with 0.1 and 0.5 μM doxazosin. Moreover, the Bcl-2/Bax ratio was higher in cells that were treated with curcumin before doxazosin or carvedilol. The present study demonstrates that curcumin controls doxazosin- and carvedilol-induced cytotoxicity and morphological changes in HepG2 cells possibly by overexpression of Nrf2.

The Anti-Non-Small Cell Lung Cancer Cell Activity by a mTOR Kinase Inhibitor PQR620

In non-small-cell lung carcinoma (NSCLC), aberrant activation of mammalian target of rapamycin (mTOR) contributes to tumorigenesis and cancer progression. PQR620 is a novel and highly-potent mTOR kinase inhibitor. We here tested its potential activity in NSCLC cells. In primary human NSCLC cells and established cell lines (A549 and NCI-H1944), PQR620 inhibited cell growth, proliferation, and cell cycle progression, as well as cell migration and invasion, while inducing significant apoptosis activation. PQR620 disrupted assembles of mTOR complex 1 (mTOR-Raptor) and mTOR complex 2 (mTOR-Rictor-Sin1), and blocked Akt, S6K1, and S6 phosphorylations in NSCLC cells. Restoring Akt-mTOR activation by a constitutively-active Akt1 (S473D) only partially inhibited PQR620-induced cytotoxicity in NSCLC cells. PQR620 was yet cytotoxic in Akt1/2-silenced NSCLC cells, supporting the existence of Akt-mTOR-independent mechanisms. Indeed, PQR620 induced sphingosine kinase 1 (SphK1) inhibition, ceramide production and oxidative stress in primary NSCLC cells. In vivo studies demonstrated that daily oral administration of a single dose of PQR620 potently inhibited primary NSCLC xenograft growth in severe combined immune deficient mice. In PQR620-treated xenograft tissues, Akt-mTOR inactivation, apoptosis induction, SphK1 inhibition and oxidative stress were detected. In conclusion, PQR620 exerted potent anti-NSCLC cell activity via mTOR-dependent and -independent mechanisms.

From Conventional to Precision Therapy in Canine Mammary Cancer: A Comprehensive Review

Canine mammary tumors (CMTs) are the most common neoplasm in intact female dogs. Canine mammary cancer (CMC) represents 50% of CMTs, and besides surgery, which is the elective treatment, additional targeted and non-targeted therapies could offer benefits in terms of survival to these patients. Also, CMC is considered a good spontaneous intermediate animal model for the research of human breast cancer (HBC), and therefore, the study of new treatments for CMC is a promising field in comparative oncology. Dogs with CMC have a comparable disease, an intact immune system, and a much shorter life span, which allows the achievement of results in a relatively short time. Besides conventional chemotherapy, innovative therapies have a large niche of opportunities. In this article, a comprehensive review of the current research in adjuvant therapies for CMC is conducted to gather available information and evaluate the perspectives. Firstly, updates are provided on the clinical-pathological approach and the use of conventional therapies, to delve later into precision therapies against therapeutic targets such as hormone receptors, tyrosine kinase receptors, p53 tumor suppressor gene, cyclooxygenases, the signaling pathways involved in epithelial-mesenchymal transition, and immunotherapy in different approaches. A comparison of the different investigations on targeted therapies in HBC is also carried out. In the last years, the increasing number of basic research studies of new promising therapeutic agents on CMC cell lines and CMC mouse xenografts is outstanding. As the main conclusion of this review, the lack of effort to bring the in vitro studies into the field of applied clinical research emerges. There is a great need for well-planned large prospective randomized clinical trials in dogs with CMC to obtain valid results for both species, humans and dogs, on the use of new therapies. Following the One Health concept, human and veterinary oncology will have to join forces to take advantage of both the economic and technological resources that are invested in HBC research, together with the innumerable advantages of dogs with CMC as a spontaneous animal model.

Reductive Stress, Bioactive Compounds, Redox-Active Metals, and Dormant Tumor Cell Biology to Develop Redox-Based Tools for the Treatment of Cancer

Significance: Cancer is related to redox biology from many points of view, such as initiation and promotion, metabolism and growth, invasion and metastasis, vascularization, or through the interaction with the immune system. In addition, this extremely complex relationship depends on the redox homeostasis of each cellular compartment, which might be used to fight cancer. Recent Advances: New ways of modulating specific and little explored aspects of redox biology have been revealed, as well as new delivery methods or uses of previously known treatments against cancer. Here, we review the latest experimental evidence regarding redox biology in cancer treatment and analyze its potential impact in the development of improved and more effective antineoplastic therapies. Critical Issues: A critical issue that deserves particular attention is the understanding that both extremes of redox biology (i.e., oxidative stress [OS] and reductive stress) might be useful or harmful in relation to cancer prevention and treatment. Future Directions: Additional research is needed to understand how to selectively induce reductive or OS adequately to avoid cancer proliferation or to induce cancer cell death.

Oral administration of natural polyphenol-loaded natural polysaccharide-cloaked lipidic nanocarriers to improve efficacy against small-cell lung cancer

Oral administration shows good tolerance in patients. Botanic anticancer drugs without serious side effects have attracted increased attention worldwide. However, oral delivery of natural anticancer drugs faces great challenges due to low solubility, gastrointestinal side effects, first-pass effects, and P-glycoprotein efflux. Here, we loaded the natural polyphenol curcumin (Cc) into natural polysaccharide-cloaked lipidic nanocarriers (Cc@CLNs) to improve the efficacy in small-cell lung cancer (SCLC) associated with oral administration. Compared to other nanoformulations, Cc@CLNs have advantages of simple operation, easy scale-up, low cost, and high safety. Cc@CLNs improve bioavailability by inducing synergistic effects (efficient cell membrane penetration, inherent muco-adhesiveness, resistance to pepsin and trypsin degradation, promoted dissolution, enhanced epithelia/M cellular uptake and inhibition of efflux transporters) and countering the tendency of nanocarriers to aggregate and fuse, which limit lipid-based nanosystems. In this study, we first evaluated the oral bioavailability of Cc@CLNs in rats and their efficacy in H446 tumor-bearing mice. The oral bioavailability increased by 8.94-fold, and the tumor growth inhibition rate doubled compared to that achieved with free Cc. We investigated the action of Cc against SCLC stem cells, and Cc@CLNs greatly enhanced this action. The expression of CD133 and ABCG2 in the Cc@CLNs group decreased by 38.05% and 32.57%, respectively, compared to the respective expression levels in the control.

Euscaphic acid and Tormentic acid protect vascular endothelial cells against hypoxia-induced apoptosis via PI3K/AKT or ERK 1/2 signaling pathway

AIMS

Euscaphic acid and Tormentic acid are aglycones of Kaji-ichigoside F1 and Rosamultin, respectively. These four compounds are pentacyclic triterpenoid, isolated from the subterranean root of the Potentilla anserina L. Based on the protective roles against hypoxia-induced apoptosis of Euscaphic acid and Tormentic acid in vascular endothelial cells, this study was designed to determine the mechanisms.

MAIN METHODS

The model of hypoxic injuries in EA. hy926 cells was established. Through applications of PI3K/AKT inhibitor, LY294002 and ERK1/2 inhibitor, PD98059, we explored the relationships between pharmacodynamic mechanisms and PI3K/AKT or ERK 1/2 signaling pathway. The anti-hypoxic effects were studied by methyl-thiazolyl-tetrazolium (MTT) assay, Hematoxylin-Eosin (HE) staining, DAPI staining, and flow cytometry. The mechanisms of anti-mitochondrial apoptosis were explored by western blot. The expressions of p-ERK 1/2, ERK 1/2, p-AKT, AKT, p-NF-κB, NF-κB, Bcl-2, Bax, Cyt C, cleaved caspase-9 and cleaved caspase-3 were detected.

KEY FINDINGS

Euscaphic acid protected vascular endothelial cells against hypoxia-induced apoptosis via ERK1/2 signaling pathway, and Tormentic acid brought its efficacy into full play via PI3K/AKT and ERK1/2 signaling pathways. In addition, PI3K/AKT signaling pathway positively regulated ERK1/2 pathway, and ERK1/2 pathway negatively regulated PI3K/AKT pathway.

SIGNIFICANCE

This evidence provides theoretical and experimental basis for the following research on anti-hypoxic drugs of Potentilla anserina L.

Kaji-Ichigoside F1 and Rosamultin Protect Vascular Endothelial Cells against Hypoxia-Induced Apoptosis via the PI3K/AKT or ERK1/2 Signaling Pathway

As a pair of differential isomers, Kaji-ichigoside F1 and Rosamultin are both pentacyclic triterpenoids isolated from the subterranean root of Potentilla anserina L., a plant used in folk medicine in western China as antihypoxia and anti-inflammatory treatments. We demonstrated that Kaji-ichigoside F1 and Rosamultin effectively prevented hypoxia-induced apoptosis in vascular endothelial cells. We established a hypoxia model, using EA.hy926 cells, to further explore the mechanisms. Hypoxia promoted the phosphorylation of AKT, ERK1/2, and NF-κB. In hypoxic cells treated with Kaji-ichigoside F1, p-ERK1/2 and p-NF-κB levels were increased, while the level of p-AKT was decreased. Treatment with Rosamultin promoted phosphorylation of ERK1/2, NF-κB, and AKT in hypoxic cells. Following the addition of LY294002, the levels of p-AKT, p-ERK1/2, and p-NF-κB decreased significantly. Addition of PD98059 resulted in reduced levels of p-ERK1/2 and p-NF-κB, while p-AKT levels were increased. Pharmacodynamic analysis demonstrated that both LY294002 and PD98059 significantly inhibited the positive effects of Kaji-ichigoside F1 on cell viability during hypoxia, consistent with the results of hematoxylin-eosin (H&E) staining, DAPI staining, and flow cytometry. The antihypoxia effects of Rosamultin were remarkably inhibited by LY294002 but promoted by PD98059. In Kaji-ichigoside F1- and Rosamultin-treated cells, Bcl2 expression was significantly upregulated, while expression of Bax and cytochrome C and levels of cleaved caspase-9 and cleaved caspase-3 were reduced. Corresponding to pharmacodynamic analysis, LY294002 inhibited the regulatory effects of Kaji-ichigoside F1 and Rosamultin on the above molecules, while PD98059 inhibited the regulatory effects of Kaji-ichigoside F1 but enhanced the regulatory effects of Rosamultin. In conclusion, Kaji-ichigoside F1 protected vascular endothelial cells against hypoxia-induced apoptosis by activating the ERK1/2 signaling pathway, which positively regulated the NF-κB signaling pathway and negatively regulated the PI3K/AKT signaling pathway. Rosamultin protected vascular endothelial cells against hypoxia-induced apoptosis by activating the PI3K/AKT signaling pathway and positively regulating ERK1/2 and NF-κB signaling pathways.

Mechanistic Understanding of Curcumin's Therapeutic Effects in Lung Cancer

Lung cancer is among the most common cancers with a high mortality rate worldwide. Despite the significant advances in diagnostic and therapeutic approaches, lung cancer prognoses and survival rates remain poor due to late diagnosis, drug resistance, and adverse effects. Therefore, new intervention therapies, such as the use of natural compounds with decreased toxicities, have been considered in lung cancer therapy. Curcumin, a natural occurring polyphenol derived from turmeric (Curcuma longa) has been studied extensively in recent years for its therapeutic effects. It has been shown that curcumin demonstrates anti-cancer effects in lung cancer through various mechanisms, including inhibition of cell proliferation, invasion, and metastasis, induction of apoptosis, epigenetic alterations, and regulation of microRNA expression. Several in vitro and in vivo studies have shown that these mechanisms are modulated by multiple molecular targets such as STAT3, EGFR, FOXO3a, TGF-β, eIF2α, COX-2, Bcl-2, PI3KAkt/mTOR, ROS, Fas/FasL, Cdc42, E-cadherin, MMPs, and adiponectin. In addition, limitations, strategies to overcome curcumin bioavailability, and potential side effects as well as clinical trials were also reviewed.

Molecular Insights into Potential Contributions of Natural Polyphenols to Lung Cancer Treatment

Naturally occurring polyphenols are believed to have beneficial effects in the prevention and treatment of a myriad of disorders due to their anti-inflammatory, antioxidant, antineoplastic, cytotoxic, and immunomodulatory activities documented in a large body of literature. In the era of molecular medicine and targeted therapy, there is a growing interest in characterizing the molecular mechanisms by which polyphenol compounds interact with multiple protein targets and signaling pathways that regulate key cellular processes under both normal and pathological conditions. Numerous studies suggest that natural polyphenols have chemopreventive and/or chemotherapeutic properties against different types of cancer by acting through different molecular mechanisms. The present review summarizes recent preclinical studies on the applications of bioactive polyphenols in lung cancer therapy, with an emphasis on the molecular mechanisms that underlie the therapeutic effects of major polyphenols on lung cancer. We also discuss the potential of the polyphenol-based combination therapy as an attractive therapeutic strategy against lung cancer.

Matrine Exerts Hepatotoxic Effects via the ROS-Dependent Mitochondrial Apoptosis Pathway and Inhibition of Nrf2-Mediated Antioxidant Response

Matrine, an alkaloid isolated from Sophora flavescens, possesses a wide range of pharmacological properties. However, the use of matrine in clinical practice is limited due to its toxic effects. The present study investigated the roles of mitochondria and reactive oxygen species (ROS) in matrine-induced liver injury. Our results showed that treatment of HL-7702 cells with matrine led to significant and concentration- and time-dependent reductions in their viability, as well as significant and concentration-dependent increases in the number of apoptotic cells and supernatant lactate dehydrogenase (LDH) activity. The treatment led to significant increases in the population of cells in S phase and significant reduction of cell proportion in G0/G1 and G2/M phases. It also significantly and concentration-dependently increased the levels of ROS and malondialdehyde (MDA) but significantly and concentration-dependently reduced superoxide dismutase (SOD) activity, level of reduced glutathione (GSH), and mitochondrial membrane potential (MMP). Matrine treatment significantly and concentration-dependently upregulated the expressions of Bax, p53, p-p53, p21, cyclin E, Fas, cleaved caspase-3, caspase-8, and caspase-9 proteins and downregulated the expressions of Bcl-2, cyclin-dependent kinase 2 (CDK2), and cyclin A. It also significantly promoted the cleavage of poly(ADP-ribose)polymerase (PARP), upregulated Kelch-like ECH-associated protein 1 (Keap1) expression, and downregulated the expressions of cellular total and nuclear Nrf2. Matrine significantly inhibited the expressions of downstream oxidoreductases (Heme oxygenase-1 (HO-1) and NAD(P)H:quinone oxidoreductases 1 (NQO-1)) and enhanced the formation of Keap1/Nrf2 protein complex. These results show that the hepatotoxic effect of matrine is exerted via inhibition of Nrf2 pathway, activation of ROS-mediated mitochondrial apoptosis pathway, and cell cycle arrest at S phase. Pretreatment with N-acetyl cysteine (NAC) partially reversed matrine-induced hepatotoxicity.

Curcumin Attenuates Adipogenesis by Inducing Preadipocyte Apoptosis and Inhibiting Adipocyte Differentiation

Patients with metabolic syndrome are at an increased risk of developing type 2 diabetes and cardiovascular diseases. The principal risk factor for development of metabolic syndrome is obesity, defined as a state of pathological hyperplasia or/and hypertrophy of adipose tissue. The number of mature adipocytes is determined by adipocyte differentiation from preadipocytes. The purpose of the present study is to investigate the effects of curcumin on adipogenesis and the underlying mechanism. To examine cell toxicity of curcumin, 3T3-L1 preadipocytes were treated with 0–50 µM curcumin for 24, 48, or 72 h, then cell viability was measured using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The effect of curcumin on the cell cycle was determined by flow cytometry. Curcumin-induced cell apoptosis was determined by the TUNEL assay and curcumin-induced caspase activation was measured by immunoblotting. The effect of curcumin on adipocyte differentiation was determined by measuring mitotic clonal expansion (MCE), expression of adipogenic transcription factors, and lipid accumulation. Results showed the viability of preadipocytes was significantly decreased by treatment with 30 µM curcumin, a concentration that caused apoptosis in preadipocytes, as assessed by the TUNEL assay, and caused activation of caspases 8, 9, and 3. A non-cytotoxic dose of curcumin (15 µM) inhibited MCE, downregulated the expression of PPARγ and C/EBPα, prevented differentiation medium-induced β-catenin downregulation, and decreased the lipid accumulation in 3T3-L1 adipocytes. In conclusion, our data show that curcumin can induce preadipocyte apoptosis and inhibit adipocyte differentiation, leading to suppression of adipogenesis.

Modulation of Mitochondrial and Epigenetic Targets by Polyphenols-rich Extract from Araucaria angustifolia in Larynx Carcinoma

Background:

Araucaria angustifolia extract (AAE) is a polyphenol-rich extract that has gained interest as a natural anticancer agent. Recent work suggests that AAE induces oxidative damage and apoptosis through its action on decreasing complex I activity of the mitochondrial Electron Transport Chain (ETC).

Aims and Methods:

In the present study, we aimed to further examine the specific targets by which AAE exerts proapoptotic effects in HEp-2 cancer cells. Specifically, the effect of AAE on the: 1) levels of pyruvate dehydrogenase was assessed by ELISA assay; 2) levels of mitochondrial ETC complexes, focusing on complex I at the gene transcript and protein level relevant to ROS generation was evaluated by multiplex ELISA followed by qRT-PCR and immunoblotting; 3) mitochondrial network distribution analysis was assessed by MitoTracker Red CMXRos; and 4) chemical variations on DNA was evaluated by dot-blotting in HEp-2 cells.

Results:

Results demonstrated that AAE increased protein levels of PDH, switching energy metabolism to oxidative metabolism. Protein expression levels of complex I and III were found decreased in AAE-treated HEp-2 cells. Analyzing the subunits of complex I, changes in protein and gene transcript levels of NDUFS7 and NDUFV2 were found. Mitochondria staining after AAE incubation revealed changes in the mitochondrial network distribution. AAE was able to induce DNA hypomethylation and decreased DNA (cytosine-5)-methyltransferase 1 activity.

Conclusion:

Our data demonstrate for the first time that AAE alters expression of NDUFS7 and NDUFV2 mitochondrial subunits and induce epigenetic changes in HEp-2 cancer cells leading to a possible suppression of oncogenes.

Lycopene Inhibits Reactive Oxygen Species-Mediated NF-κB Signaling and Induces Apoptosis in Pancreatic Cancer Cells

Generation of excess quantities of reactive oxygen species (ROS) caused by mitochondrial dysfunction facilitates rapid growth of pancreatic cancer cells. Elevated ROS levels in cancer cells cause an anti-apoptotic effect by activating survival signaling pathways, such as NF-κB and its target gene expression. Lycopene, a carotenoid found in tomatoes and a potent antioxidant, displays a protective effect against pancreatic cancer. The present study was designed to determine if lycopene induces apoptosis of pancreatic cancer PANC-1 cells by decreasing intracellular and mitochondrial ROS levels, and consequently suppressing NF-κB activation and expression of NF-κB target genes including cIAP1, cIAP2, and survivin. The results show that the lycopene decreased intracellular and mitochondrial ROS levels, mitochondrial function (determined by the mitochondrial membrane potential and oxygen consumption rate), NF-κB activity, and expression of NF-κB-dependent survival genes in PANC-1 cells. Lycopene reduced cell viability with increases in active caspase-3 and the Bax to Bcl-2 ratio in PANC-1 cells. These findings suggest that supplementation of lycopene could potentially reduce the incidence of pancreatic cancer.

Structure-Based Classification and Anti-Cancer Effects of Plant Metabolites

A variety of malignant cancers affect the global human population. Although a wide variety of approaches to cancer treatment have been studied and used clinically (surgery, radiotherapy, chemotherapy, and immunotherapy), the toxic side effects of cancer therapies have a negative impact on patients and impede progress in conquering cancer. Plant metabolites are emerging as new leads for anti-cancer drug development. This review summarizes these plant metabolites with regard to their structures and the types of cancer against which they show activity, organized by the organ or tissues in which each cancer forms. This information will be helpful for understanding the current state of knowledge of the anti-cancer effects of various plant metabolites against major types of cancer for the further development of novel anti-cancer drugs.

In vitro and in vivo activity of liposome-encapsulated curcumin for naturally occurring canine cancers

Curcumin has well-established anti-cancer properties in vitro, however, its therapeutic potential has been hindered by its poor bioavailability. Lipocurc is a proprietary liposome-encapsulated curcumin formulation that enables intravenous delivery and has been shown to reach its highest concentration within lung tissue. The goal of this study was to characterize the anti-cancer and anti-angiogenic activity of Lipocurc in vitro, in addition to evaluating Lipocurc infusions in dogs with naturally occurring cancer. We therefore evaluated the effect of Lipocurc, relative to free curcumin, on the viability of canine osteosarcoma, melanoma and mammary carcinoma cell lines, as well as the ability of Lipocurc to inhibit endothelial cell viability, migration and tube formation. We also undertook a pilot clinical trial consisting of four weekly 8-hour Lipocurc infusions in 10 cancer-bearing dogs. Tumour cell proliferation was inhibited by curcumin at concentrations exceeding those achievable in the lung tissue of dogs. Similarly, equivalent high concentrations of Lipocurc and curcumin also inhibited endothelial cell viability, migration and tube formation. Four out of six dogs completing planned infusions of Lipocurc experienced stable disease; however, no radiographic responses were detected.

Triptolide Induces Apoptosis Through Fas Death and Mitochondrial Pathways in HepaRG Cell Line

Triptolide isolated from the traditional Chinese herb Tripterygium wilfordii Hook F., possesses anti-tumor, anti-fertility, and anti-inflammatory properties. Triptolide-induced hepatotoxicity has continued to engage the attention of researchers. However, not much is yet known about the cytotoxicity of triptolide, and the precise mechanisms involved. In the present study, we investigated the cytotoxicity of triptolide and its underlying mechanisms, using the in vitro model (HepaRG cell). The results demonstrated that triptolide significantly reduced cell viability and induced apoptosis in HepaRG cells in a dose- and time-dependent manner. Triptolide treatment also provoked reactive oxygen species (ROS) generation and depolarization of mitochondrial membrane potential (MMP). Moreover, triptolide dose-dependently increased the protein expression levels of Fas, Bax, p53, p21, cyclin E, cleaved caspase-3, 8, and 9; and subsequent cleavage of poly (ADP-ribose) polymerase (PARP). However, the protein expression of Bcl-2, cyclin A, and CDK 2 were significantly decreased. These results suggest that triptolide inhibits cell proliferation and induces apoptosis via the Fas death pathway and the mitochondrial pathway.

Rhein Induces Cell Death in HepaRG Cells through Cell Cycle Arrest and Apoptotic Pathway

Rhein, a naturally occurring active anthraquinone found abundantly in various medicinal and nutritional herbs, possesses a wide spectrum of pharmacological effects. Furthermore, previous studies have reported that rhein could induce hepatotoxicity in rats. However, its cytotoxicity and potential molecular mechanisms remain unclear. Therefore, the present study aimed to investigate the cytotoxicity of rhein on HepaRG cells and the underlying mechanisms of its cytotoxicity. Our results demonstrate, by 3-(4,5-dimethyl thiazol-2-yl-)-2,5-diphenyl tetrazolium bromide (MTT) and Annexin V-fluoresce isothiocyanate (FITC)/propidium iodide (PI) double-staining assays, that rhein significantly inhibited cell viability and induced apoptosis in HepaRG cells. Moreover, rhein treatment resulted in the generation of reactive oxygen species (ROS), loss of mitochondrial membrane potential (MMP), and S phase cell cycle arrest. The results of Western blotting showed that rhein treatment resulted in a significant increase in the protein levels of Fas, p53, p21, Bax, cleaved caspases-3, -8, -9, and poly(ADP-ribose)polymerase (PARP). The protein expression of Bcl-2, cyclin A, and cyclin-dependent kinase 2 (CDK 2) was decreased. In conclusion, these results suggest that rhein treatment could inhibit cell viability of HepaRG cells and induce cell death through cell cycle arrest in the S phase and activation of Fas- and mitochondrial-mediated pathways of apoptosis. These findings emphasize the need to assess the risk of exposure for humans to rhein.

Pim kinase inhibition sensitizes FLT3-ITD acute myeloid leukemia cells to topoisomerase 2 inhibitors through increased DNA damage and oxidative stress

Internal tandem duplication of fms-like tyrosine kinase-3 (FLT3-ITD) is frequent (30 percent) in acute myeloid leukemia (AML), and is associated with short disease-free survival following chemotherapy. The serine threonine kinase Pim-1 is a pro-survival oncogene transcriptionally upregulated by FLT3-ITD that also promotes its signaling in a positive feedback loop. Thus inhibiting Pim-1 represents an attractive approach in targeting FLT3-ITD cells. Indeed, co-treatment with the pan-Pim kinase inhibitor AZD1208 or expression of a kinase-dead Pim-1 mutant sensitized FLT3-ITD cell lines to apoptosis triggered by chemotherapy drugs including the topoisomerase 2 inhibitors daunorubicin, etoposide and mitoxantrone, but not the nucleoside analog cytarabine. AZD1208 sensitized primary AML cells with FLT3-ITD to topoisomerase 2 inhibitors, but did not sensitize AML cells with wild-type FLT3 or remission bone marrow cells, supporting a favorable therapeutic index. Mechanistically, the enhanced apoptosis observed with AZD1208 and topoisomerase 2 inhibitor combination treatment was associated with increased DNA double-strand breaks and increased levels of reactive oxygen species (ROS), and co-treatment with the ROS scavenger N-acetyl cysteine rescued FLT3-ITD cells from AZD1208 sensitization to topoisomerase 2 inhibitors. Our data support testing of Pim kinase inhibitors with topoisomerase 2 inhibitors, but not with cytarabine, to improve treatment outcomes in AML with FLT3-ITD.

Cytoplasmic vacuolization in cell death and survival

Cytoplasmic vacuolization (also called cytoplasmic vacuolation) is a well-known morphological phenomenon observed in mammalian cells after exposure to bacterial or viral pathogens as well as to various natural and artificial low-molecular-weight compounds. Vacuolization often accompanies cell death; however, its role in cell death processes remains unclear. This can be attributed to studying vacuolization at the level of morphology for many years. At the same time, new data on the molecular mechanisms of the vacuole formation and structure have become available. In addition, numerous examples of the association between vacuolization and previously unknown cell death types have been reported. Here, we review these data to make a deeper insight into the role of cytoplasmic vacuolization in cell death and survival.

TRAIL and curcumin codelivery nanoparticles enhance TRAIL-induced apoptosis through upregulation of death receptors

Active targeting nanoparticles were developed to simultaneously codeliver tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and Curcumin (Cur). In the nanoparticles (TRAIL-Cur-NPs), TRAIL was used as both active targeting ligand and therapeutic agent, and Cur could upregulate death receptors (DR4 and DR5) to increase the apoptosis-inducing effects of TRAIL. Compared with corresponding free drugs, TRAIL-Cur-NPs group showed enhanced cellular uptake, cytotoxicity and apoptosis induction effect on HCT116 colon cancer cells. In addition, in vivo anticancer studies suggested that TRAIL-Cur-NPs had superior therapeutic effect on tumors without obvious toxicity, which was mainly due to the high tumor targeting and synergistic effect of TRAIL and Cur. The synergistic mechanism of improved antitumor efficacy was proved to be upregulation of DR4 and DR5 in tumor cells induced by Cur. Thus, the prepared codelivery nanoparticles may have potential applications in colorectal cancer therapy.

Curcumin-coordinated nanoparticles with improved stability for reactive oxygen species-responsive drug delivery in lung cancer therapy

BACKGROUND

The natural compound curcumin (Cur) can regulate growth inhibition and apoptosis in various cancer cell lines, although its clinical applications are restricted by extreme water insolubility and instability. To overcome these hurdles, we fabricated a Cur-coordinated reactive oxygen species (ROS)-responsive nanoparticle using the interaction between boronic acid and Cur.

MATERIALS AND METHODS

We synthesized a highly biocompatible 4-(hydroxymethyl) phenylboronic acid (HPBA)-modified poly(ethylene glycol) (PEG)-grafted poly(acrylic acid) polymer (PPH) and fabricated a Cur-coordinated ROS-responsive nanoparticle (denoted by PPHC) based on the interaction between boronic acid and Cur. The mean diameter of the Cur-coordinated PPHC nanoparticle was 163.8 nm and its zeta potential was -0.31 mV. The Cur-coordinated PPHC nanoparticle improved Cur stability in physiological environment and could timely release Cur in response to hydrogen peroxide (H2O2). PPHC nanoparticles demonstrated potent antiproliferative effect in vitro in A549 cancer cells. Furthermore, the viability of cells treated with PPHC nanoparticles was significantly increased in the presence of N-acetyl-cysteine (NAC), which blocks Cur release through ROS inhibition. Simultaneously, the ROS level measured in A549 cells after incubation with PPHC nanoparticles exhibited an obvious downregulation, which further proved that ROS depression indeed influenced the therapeutic effect of Cur in PPHC nanoparticles. Moreover, pretreatment with phosphate-buffered saline (PBS) significantly impaired the cytotoxic effect of Cur in A549 cells in vitro while causing less damage to the activity of Cur in PPHC nanoparticle.

CONCLUSION

The Cur-coordinated nanoparticles developed in this study improved Cur stability, which could further release Cur in a ROS-dependent manner in cancer cells.

Triggering of apoptosis in osteosarcoma cells by graphene/single-walled carbon nanotube hybrids via the ROS-mediated mitochondrial pathway

Carbon nanomaterials are increasingly significant in the biological and medical fields, especially becoming promising candidates in treating difficult and complicated disease. Graphene/single-walled carbon nanotubes (G/SWCNT) hybrids is 3D structure which has been constructed by combining 1D single-walled carbon nanotubes (SWCNTs) and 2D graphene. However, the effects of the nanomaterial on biological systems are limited. In this study, we report a systematic investigation of the cytotoxicity and in vivo biodistribution of G/SWCNT hybrids on osteosarcoma cells (HOS and U2OS). The CCK-8, neutral red, and lactic dehydrogenase assays demonstrated that the cytotoxicity of G/SWCNT hybrids exhibits a dose-dependent behavior on osteosarcoma cells. In our conditions, the hybrids were less cytotoxic than graphene and single-walled carbon nanotubes. The results also showed the apoptosis of osteosarcoma cells induced by G/SWCNT hybrids was through the increase of intracellular reactive oxygen species, the decrease of mitochondrial membrane potential, the alternation of apoptosis-related proteins, and then triggered the ROS-mediated mitochondrial pathway. Moreover, the in vivo biodistribution of G/SWCNT hybrids was observed by histological analysis of major organs in mice, and showed that organs were neither damaged nor inflammatory. This study demonstrated that G/SWCNT hybrids could serve as a potential platform in anticancer therapy. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 443-453, 2017.

Spices for Prevention and Treatment of Cancers

Spices have been widely used as food flavorings and folk medicines for thousands of years. Numerous studies have documented the antioxidant, anti-inflammatory and immunomodulatory effects of spices, which might be related to prevention and treatment of several cancers, including lung, liver, breast, stomach, colorectum, cervix, and prostate cancers. Several spices are potential sources for prevention and treatment of cancers, such as Curcuma longa (tumeric), Nigella sativa (black cumin), Zingiber officinale (ginger), Allium sativum (garlic), Crocus sativus (saffron), Piper nigrum (black pepper) and Capsicum annum (chili pepper), which contained several important bioactive compounds, such as curcumin, thymoquinone, piperine and capsaicin. The main mechanisms of action include inducing apoptosis, inhibiting proliferation, migration and invasion of tumors, and sensitizing tumors to radiotherapy and chemotherapy. This review summarized recent studies on some spices for prevention and treatment of cancers, and special attention was paid to bioactive components and mechanisms of action.

Mitochondrial Fission Increases Apoptosis and Decreases Autophagy in Renal Proximal Tubular Epithelial Cells Treated with High Glucose

The aim of this study was to examine the effect of mitochondrial morphogenesis changes on apoptosis and autophagy of high-glucose-treated proximal tubular epithelial cells (HK2). Cell viability, apoptosis, and mitochondrial morphogenesis were examined using crystal violet, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL), and mitotracker staining, respectively. High glucose inhibited cell viability and induced mitochondrial fission in HK2 cells. After depleting mitofusin 1 (MFN1), the MFN1(-) HK2 cells (fission type) became more susceptible to high-glucose-induced apoptosis and mitochondrial fragmentation observed by TUNEL and mitotracker assays. In siMFN2 HK2 cells (fission type), mitochondria were highly fragmented (>80% fission rate) with or without high-glucose treatment; however, siFIS1 (mitochondrial fission protein 1) HK2 cells (fusion type) exhibited little fragmentation (<13%). High-glucose treatment induced autophagy, characterized by the formation of autophagosome and microtubule-associated protein light chain 3 (LC3) B-II, as observed by transmission electron microscopy and western blotting, respectively. LC3B-II levels decreased in both MFN1(-) and siMFN2 HK2 cells, but increased in siFIS1 HK2 cells. Moreover, autophagy displays a protective role against high-glucose-induced cell death based on cotreatment with autophagy inhibitors (3-methyladenine and chloroquine). Mitochondrial fission may increase apoptosis and decrease autophagy of high-glucose-treated HK2 cells.

Curcumin and Health

Nowadays, there are some molecules that have shown over the years a high capacity to act against relevant pathologies such as cardiovascular disease, neurodegenerative disorders or cancer. This article provides a brief review about the origin, bioavailability and new research on curcumin and synthetized derivatives. It examines the beneficial effects on health, delving into aspects such as cancer, cardiovascular effects, metabolic syndrome, antioxidant capacity, anti-inflammatory properties, and neurological, liver and respiratory disorders. Thanks to all these activities, curcumin is positioned as an interesting nutraceutical. This is the reason why it has been subjected to several modifications in its structure and administration form that have permitted an increase in bioavailability and effectiveness against different diseases, decreasing the mortality and morbidity associated to these pathologies.

Polyphenols as Modulator of Oxidative Stress in Cancer Disease: New Therapeutic Strategies

Cancer onset and progression have been linked to oxidative stress by increasing DNA mutations or inducing DNA damage, genome instability, and cell proliferation and therefore antioxidant agents could interfere with carcinogenesis. It is well known that conventional radio-/chemotherapies influence tumour outcome through ROS modulation. Since these antitumour treatments have important side effects, the challenge is to develop new anticancer therapeutic strategies more effective and less toxic for patients. To this purpose, many natural polyphenols have emerged as very promising anticancer bioactive compounds. Beside their well-known antioxidant activities, several polyphenols target epigenetic processes involved in cancer development through the modulation of oxidative stress. An alternative strategy to the cytotoxic treatment is an approach leading to cytostasis through the induction of therapy-induced senescence. Many anticancer polyphenols cause cellular growth arrest through the induction of a ROS-dependent premature senescence and are considered promising antitumour therapeutic tools. Furthermore, one of the most innovative and interesting topics is the evaluation of efficacy of prooxidant therapies on cancer stem cells (CSCs). Several ROS inducers-polyphenols can impact CSCs metabolisms and self-renewal related pathways. Natural polyphenol roles, mainly in chemoprevention and cancer therapies, are described and discussed in the light of the current literature data.

Curcumin induces crosstalk between autophagy and apoptosis mediated by calcium release from the endoplasmic reticulum, lysosomal destabilization and mitochondrial events

Curcumin, a major active component of turmeric (Curcuma longa, L.), has anticancer effects. In vitro studies suggest that curcumin inhibits cancer cell growth by activating apoptosis, but the mechanism underlying these effects is still unclear. Here, we investigated the mechanisms leading to apoptosis in curcumin-treated cells. Curcumin induced endoplasmic reticulum stress causing calcium release, with a destabilization of the mitochondrial compartment resulting in apoptosis. These events were also associated with lysosomal membrane permeabilization and of caspase-8 activation, mediated by cathepsins and calpains, leading to Bid cleavage. Truncated tBid disrupts mitochondrial homeostasis and enhance apoptosis. We followed the induction of autophagy, marked by the formation of autophagosomes, by staining with acridine orange in cells exposed curcumin. At this concentration, only the early events of apoptosis (initial mitochondrial destabilization with any other manifestations) were detectable. Western blotting demonstrated the conversion of LC3-I to LC3-II (light chain 3), a marker of active autophagosome formation. We also found that the production of reactive oxygen species and formation of autophagosomes following curcumin treatment was almost completely blocked by N-acetylcystein, the mitochondrial specific antioxidants MitoQ10 and SKQ1, the calcium chelators, EGTA-AM or BAPTA-AM, and the mitochondrial calcium uniporter inhibitor, ruthenium red. Curcumin-induced autophagy failed to rescue all cells and most cells underwent type II cell death following the initial autophagic processes. All together, these data imply a fail-secure mechanism regulated by autophagy in the action of curcumin, suggesting a therapeutic potential for curcumin. Offering a novel and effective strategy for the treatment of malignant cells.

Dietary agents for prevention and treatment of lung cancer

Lung cancer is a prominent cause of cancer-associated mortality worldwide. The main reason for high mortality due to lung cancer is attributable to the fact that the diagnosis is generally made when it has spread beyond a curable stage and cannot be treated surgically or with radiation therapy. Therefore, new approaches like dietary modifications could be extremely useful in reducing lung cancer incidences. Several fruits and vegetables offer a variety of bioactive compounds to afford protection against several diseases, including lung cancer. A number of research studies involving dietary agents provide strong evidence for their role in the prevention and treatment of lung cancer, and have identified their molecular mechanisms of action and potential targets. In this review article, we summarize data from in-vitro and in-vivo studies and where available, in clinical trials, on the effects of some of the most promising dietary agents against lung cancer.

Evodiamine induces G2/M arrest and apoptosis via mitochondrial and endoplasmic reticulum pathways in H446 and H1688 human small-cell lung cancer cells

The goal of this study was to evaluate the ability of EVO to decrease cell viability and promote cell cycle arrest and apoptosis in small cell lung cancer (SCLC) cells. Lung cancer has the highest incidence and mortality rates among all cancers. Chemotherapy is the primary treatment for SCLC; however, the drugs that are currently used for SCLC are less effective than those used for non-small cell lung cancer (NSCLC). Therefore, it is necessary to develop new drugs to treat SCLC. In this study, the effects of evodiamine (EVO) on cell growth, cell cycle arrest and apoptosis were investigated in the human SCLC cell lines NCI-H446 and NCI-H1688. The results represent the first report that EVO can significantly inhibit the viability of both H446 and H1688 cells in dose- and time-dependent manners. EVO induced cell cycle arrest at G2/M phase, induced apoptosis by up-regulating the expression of caspase-12 and cytochrome C protein, and induced the expression of Bax mRNA and by down-regulating of the expression of Bcl-2 mRNA in both H446 and H1688 cells. However, there was no effect on the protein expression of caspase-8. Taken together, the inhibitory effects of EVO on the growth of H446 and H1688 cells might be attributable to G2/M arrest and subsequent apoptosis, through mitochondria-dependent and endoplasmic reticulum stress-induced pathways (intrinsic caspase-dependent pathways) but not through the death receptor-induced pathway (extrinsic caspase-dependent pathway). Our findings suggest that EVO is a promising novel and potent antitumor drug candidate for SCLC. Furthermore, the cell cycle, the mitochondria and the ER stress pathways are rational targets for the future development of an EVO delivery system to treat SCLC.

Maslinic acid induces mitochondrial apoptosis and suppresses HIF-1α expression in A549 lung cancer cells under normoxic and hypoxic conditions

The apoptotic effects of maslinic acid (MA) at 4, 8, 16, 32 and 64 μmol/L on human lung cancer A549 cells under normoxic and hypoxic conditions were examined. MA at 4–64 and 16–64 μmol/L lowered Bcl-2 expression under normoxic and hypoxic conditions, respectively (p < 0.05). This agent at 4–64 μmol/L decreased Na⁺-K⁺-ATPase activity and increased caspase-3 expression under normoxic conditions, but at 8–64 μmol/L it caused these changes under hypoxic conditions (p < 0.05). MA up-regulated caspase-8, cytochrome c and apoptosis-inducing factor expression under normoxic and hypoxic conditions at 8–64 μmol/L and 32–64 μmol/L, respectively (p < 0.05). MA down-regulated hypoxia-inducible factor (HIF)-1α, vascular endothelial growth factor (VEGF), survivin and inducible nitric oxide synthase (iNOS) expression under normoxic and hypoxic conditions at 8–64 and 16–64 μmol/L, respectively (p < 0.05). After cells were pre-treated with YC-1, an inhibitor of HIF-1α, MA failed to affect the protein expression of HIF-1α, VEGF, survivin and iNOS (p > 0.05). MA at 8-64 and 32-64 μmol/L reduced reactive oxygen species and nitric oxide levels under both conditions (p < 0.05). These findings suggest that maslinic acid, a pentacyclic triterpenic acid, exerted its cytotoxic activities toward A549 cells by mediating mitochondrial apoptosis and the HIF-1α pathway.

Curcumin promotes apoptosis by activating the p53-miR-192-5p/215-XIAP pathway in non-small cell lung cancer

Curcumin has attracted increasing interest as an anti-cancer drug for decades. The mechanisms of action involve multiple cancer-related signaling pathways. Recent studies highlighted curcumin has epigenetic regulatory effects on miRNA in cancers. In the present study, we demonstrated the proapoptotic effects of curcumin in vitro and in vivo. miRNA microarray and qPCR indicated that miR-192-5p and miR-215 were the most responsive miRNAs upon curcumin treatment in H460 and A427 cells. Functional studies showed miR-192-5p/215 were putative tumor suppressors in non-small cell lung cancer. Curcumin also promoted miR-192-5p/215 expressions in A549 cells (p53 wild type) but not in H1299 cells (p53-null). Conditional knockdown of p53 by tetracycline inducible expression system significantly abrogated curcumin-induced miR-192-5p/215 upregulation in the p53 wild-type H460, A427 and A549 cells. Conversely, ectopic expression of exogenous wild-type but not R273H mutant p53 in the p53-null H1299 cells enabled miR-192-5p/215 response to curcumin treatment. The proapoptotic effects of curcumin also depended on miR-192-5p/215 induction, and antagonizing miR-192-5p/215 expression attenuated curcumin-induced apoptosis in H460, A427 and A549 cells, but not in H1299 cells. Finally, X-linked inhibitor of apoptosis (XIAP) is proved to be a novel transcriptional target of miR-192-5p/215. Taken together, this study highlights that the proapoptotic effects of curcumin depend on miR-192-5p/215 induction and the p53-miR-192-5p/215-XIAP pathway is an important therapeutic target for non-small cell lung cancer.

ZnO nanowire arrays exhibit cytotoxic distinction to cancer cells with different surface charge density: cytotoxicity is charge-dependent

Using distinct ZnO NW arrays to provide positively charged surface, charge effect on cytotoxicity is investigated. 1-D structure of ZnO NWs is the main factor leads to apoptosis accompanied by ROS enrichment and GSH depletion, and electrostatic interaction between positively charged ZnO NWs and negatively charged cells make important contribution to the degree of ZnO NW arrays damaging cell membrane.

Curcumin induces apoptosis through mitochondrial pathway and caspases activation in human melanoma cells

Melanoma is the most malignant skin cancer and is highly resistant to chemotherapy and radiotherapy. Curcumin is a component of turmeric, the yellow spice derived from the rhizome of Curcuma longa. It has been demonstrated to modulate multiple cell signaling pathways, including apoptosis, proliferation, angiogenesis and inflammation. In this study, we studied the signaling pathways involved in melanoma cell death after treatment with curcumin using western blotting. Colorimetric assays (MTT) assessed cell viability. Flow cytometry and DNA laddering evaluated cell apoptosis. Fluorescent microscopy was used to evaluate of Hoechst 33342 staining of nuclei. The result demonstrated that curcumin could induce apoptosis and inhibit proliferation in melanoma cells. Curcumin stimulated the expression of pro-apoptotic Bax, and inhibited the activation of anti-apoptotic Mcl-1 and Bcl-2. During curcumin treatment, caspase-8 and Caspase-3 were cleaved in time and dose-dependent manners. Curcumin treatment also altered the expressions of apoptosis associated proteins NF-κB, p38 and p53. Curcumin induced DNA double strand breaks, which were indicated by phosphorylated H2AX. Our data suggested that curcumin could be used as a novel and effective approach for the treatment of melanoma.

Curcumin inhibits the replication of enterovirus 71 in vitro

Human enterovirus 71 (EV71) is the main causative pathogen of hand, foot, and mouth disease (HFMD) in children. The epidemic of HFMD has been a public health problem in Asia-Pacific region for decades, and no vaccine and effective antiviral medicine are available. Curcumin has been used as a traditional medicine for centuries to treat a diversity of disorders including viral infections. In this study, we demonstrated that curcumin showed potent antiviral effect again EV71. In Vero cells infected with EV71, the addition of curcumin significantly suppressed the synthesis of viral RNA, the expression of viral protein, and the overall production of viral progeny. Similar with the previous reports, curcumin reduced the production of ROS induced by viral infection. However, the antioxidant property of curcumin did not contribute to its antiviral activity, since N-acetyl-l-cysteine, the potent antioxidant failed to suppress viral replication. This study also showed that extracellular signal-regulated kinase (ERK) was activated by either viral infection or curcumin treatment, but the activated ERK did not interfere with the antiviral effect of curcumin, indicating ERK is not involved in the antiviral mechanism of curcumin. Unlike the previous reports that curcumin inhibited protein degradation through ubiquitin–proteasome system (UPS), we found that curcumin had no impact on UPS in control cells. However, curcumin did reduce the activity of proteasomes which was increased by viral infection. In addition, the accumulation of the short-lived proteins, p53 and p21, was increased by the treatment of curcumin in EV71-infected cells. We further probed the antiviral mechanism of curcumin by examining the expression of GBF1 and PI4KB, both of which are required for the formation of viral replication complex. We found that curcumin significantly reduced the level of both proteins. Moreover, the decreased expression of either GBF1 or PI4KB by the application of siRNAs was sufficient to suppress viral replication. We also demonstrated that curcumin showed anti-apoptotic activity at the early stage of viral infection. The results of this study provide solid evidence that curcumin has potent anti-EV71 activity. Whether or not the down-regulated GBF1 and PI4KB by curcumin contribute to its antiviral effect needs further studies.