RETRACTED: Tea polyphenols enhance cisplatin chemosensitivity in cervical cancer cells via induction of apoptosis

Effect of cashew (Anacardium occidentale L.) nut-supplemented diet on steroidogenic enzymes, hormonal and oxidative imbalances, and sperm parameters in cisplatin-induced reproductive toxicity in male rats

Cisplatin (CP) is a chemotherapeutic/anticancer drug culpable in sperm and testicular damage, but the use of dietary patterns has been reported to averse this effect. To date, no report on the use of roasted cashew nut-supplemented diets (RCNSD) against chemotherapy-induced testicular damage has been presented. In this study, the effect of 10% and 20% RCNSD on reproductive hormones, sperm parameters, testicular and epididymal antioxidant status, and steroidogenic enzymes activities in CP-induced rats were determined. Interestingly, these parameters were boosted, but with a decrement in radical species level in the testes/epididymis of CP-induced rats fed with RCNSD as against the untreated CP-induced rats. The modulatory effect of RCNSD on the tested reproductive parameters in studied tissues could be among the mechanism of action, by which RCNSD mitigates andrological toxicity. Hence, RCNSD could be harnessed as a functional food/nutraceutical agent for alleviating the andrological toxicity of CP-induced male reproduction. PRACTICAL APPLICATIONS: Consumption of cashew nuts has been a great benefit to human health, as a result of its richness in nutritional constituents including biologically active amino acids, tocopherols, fatty acids, polyphenols, and selenium, among others. Cashew nuts are mostly consumed fried/roasted, with yoghurt, as a paste, or used as an ingredient in confectionery products. The folkloric use of cashew nuts in the management of cardiovascular diseases, male reproductive disorders, and diabetes has been reported. In this study, the ability of roasted cashew nut-supplemented diets to modulate reproductive hormones, sperm parameters, testicular and epididymal antioxidant status, and steroidogenic enzymes activities in CP-induced reproductive toxicity in male rats was revealed, thus, indicating its possible use, clinically, in the management of reproductive toxicity induced by cancer drugs.

Preparation of Catechin Nanoemulsion from Oolong Tea Leaf Waste and Its Inhibition of Prostate Cancer Cells DU-145 and Tumors in Mice

Anti-cancer activity of catechin nanoemulsions prepared from Oolong tea leaf waste was studied on prostate cancer cells DU-145 and DU-145-induced tumors in mice. Catechin nanoemulsions composed of lecithin, Tween-80 and water in an appropriate proportion was prepared with high stability, particle size of 11.3 nm, zeta potential of -67.2 mV and encapsulation efficiency of 83.4%. Catechin nanoemulsions were more effective than extracts in inhibiting DU-145 cell growth, with the IC50 being 13.52 and 214.6 μg/mL, respectively, after 48 h incubation. Furthermore, both catechin nanoemulsions and extracts could raise caspase-8, caspase-9 and caspase-3 activities for DU-145 cell apoptosis, arresting the cell cycle at S and G2/M phases. Compared to control, catechin nanoemulsion at 20 μg/mL and paclitaxel at 10 μg/mL were the most effective in reducing tumor volume by 41.3% and 52.5% and tumor weight by 77.5% and 90.6% in mice, respectively, through a decrease in EGF and VEGF levels in serum.

Molecular and biological functions of gingerol as a natural effective therapeutic drug for cervical cancer

Cervical cancer is one of the most common and important gynecological cancers, which has a global concern with an increasing number of patients and mortality rates. Today, most women in the world who suffer from cervical cancer are developing advanced stages of the disease. Smoking and even exposure to secondhand smoke, infections caused by the human papillomavirus, immune system dysfunction and high-risk individual-social behaviors are among the most important predisposing factors for this type of cancer. In addition, papilloma virus infection plays a more prominent role in cervical cancer. Surgery, chemotherapy or radical hysterectomy, and radiotherapy are effective treatments for this condition, the side effects of these methods endanger a person's quality of life and cause other problems in other parts of the body. Studies show that herbal medicines, including taxol, camptothecin and combretastatins, have been shown to be effective in treating cervical cancer. Ginger (Zingiber officinale, Zingiberaceae) is one of the plants with valuable compounds such as gingerols, paradols and shogoals, which is a rich source of antioxidants, anti-cancer and anti-inflammatory agents. Numerous studies have reported the therapeutic effects of this plant through various pathways in cervical cancer. In this article, we look at the signaling mechanisms and pathways in which ginger is used to treat cervical cancer.

Microwave-prepared mesoporous graphene as adsorbent and matrix of surface-assisted laser desorption/ionization mass spectrometry for the enrichment and rapid detection of polyphenols in biological samples

In this work, a three-dimensional mesoporous graphene (3D-MG) prepared by microwave-assisted method was used as both the adsorbent and the matrix of SALDI-TOF MS for polyphenols analysis in biological samples. The outstanding microstructure of 3D-MG made it sensitive in small molecule analysis with low background interference and able to enrich trace polyphenols from complex samples. 3D-MG performed much better in the detection of small molecules than graphene prepared by ordinary method, and could further improve sensitivity and reduce detection limit by enrichment. Due to its unique hierarchical mesoporous structure, the interference of biological macromolecules in SALDI analysis could be eliminated after treatment by 3D-MG. Finally, 3D-MG was successfully applied to the screening of polyphenols in biological samples with simple process and high throughput. Moreover, this strategy had also promoted the development of new matrix in SALDI-TOF MS analysis, in which the matrix properties, adsorption capabilities and size effects of graphene-based materials were combined for the first time.

Inhibitory effect of bound polyphenol from foxtail millet bran on miR-149 methylation increases the chemosensitivity of human colorectal cancer HCT-8/Fu cells

Nature polyphenols widely present in plants and foods are promising candidates in cancer chemotherapy. Emerging evidence has shown that plant polyphenols regulate the expression of miRNAs to exert the anti-Multidrug resistance (MDR) activity, which partly attributes to their regulation on miRNAs methylation. Our previous study found that bound polyphenol from foxtail millet bran (BPIS) had potential as an anti-MDR agent for colorectal cancer (CRC), but its mechanism remains unclear. The present findings demonstrated that BPIS upregulated the expression of miR-149 by reducing the methylation of its CpG islands, which subsequently induced the cell cycle arrest in G2/M phase, resulting in enhancing the chemo-sensitivity of HCT-8/Fu cells. Mechanically, BPIS and its active components (FA and p-CA) reduced miR-149 methylation by inhibiting the expression levels of DNA methyltransferases, promoting a remarkable increase of miR-149 expression. Further, the increased miR-149 induced cell cycle arrest in G₂/M phase by inhibiting the expression of Akt, Cyclin B1 and CDK1, thus increasing the chemosensitivity of HCT-8/Fu cells. Additionally, a strong inducer of DNA de-methylation (5-aza-dc) treatment markedly increased the chemosensitivity of CRC through elevating miR-149 expression, which indicates the hypermethylation of miR-149 may be the key cause of drug resistance in CRC. The study indicates that the enhanced chemosensitivity of BPIS on CRC is mainly attributed to the increase of miR-149 expression induced by methylation inhibition.

Synergistic Cytotoxic Effect from Combination of Wedelolactone and Cisplatin in HeLa Cell Line: A Novel Finding

CONTEXT AND OBJECTIVE

Cisplatin is a platinum drug in current clinical use for the treatment of cervical cancer. However, drug toxicity and resistance are its two major limitations. The aim of this investigation was to test the cytotoxic activity of potential phytochemicals alone and in combination with cisplatin in cervical cancer cells.

METHODS

In this study, cytotoxicity of phytochemicals including wedelolactone (WDL), betulinic acid (BA) and epigallocatechin gallate (EGCG) was investigated in human cervical cancer cell line HeLa through 3-(4, 5-Dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) reduction assay. Combined drug action resulting from the combination of cisplatin with WDL and BA was investigated in the same cell line through median effect principle. The combination index (CI) was taken as a measure of combined drug action.

RESULTS

BA resulted in synergistic outcome when co-administered with cisplatin at 0/0 time; (bolus administration) while administration of either drug (cisplatin or BA) four hours before the other (0/4 or 4/0) resulted in antagonistic action. WDL, on the other hand, was found out to be synergistic at any of the applied sequence of drug administration (0/0, 0/4 or 4/0).

DISCUSSION AND CONCLUSION

This is the first study reporting cytotoxic activity of WDL in HeLa cells either as single agent or in combination with cisplatin. These results support the idea that sequential combination of cisplatin with WDL and BA may work effectively in cervical cancer cells.

Screening and Discovery of New Potential Biomarkers and Small Molecule Drugs for Cervical Cancer: A Bioinformatics Analysis

BACKGROUND

Cervical cancer (CC) is the second most common type of malignant tumor survival rate is low in advanced stage, metastatic, and recurrent CC patients. This study aimed at identifying potential genes and drugs for CC diagnosis and targeting therapies.

METHODS

Three GEO mRNA microarray datasets of CC tissues and non-cancerous tissues were analyzed for differentially expressed genes (DEGs) by limma package. GO (Gene Ontologies) and KEGG (Kyoto Encyclopedia of Genes and Genomes) were used to explore the relationships between the DEGs. Protein-protein interaction (PPI) of these genes was established by the STRING database. MCODE was used for screening significant modules in the PPI networks to select hub genes. Biochemical mechanisms of the hub genes were investigated with Metascape. GEPIA database was used for validating the core genes. According to these DEGs, molecular candidates for CC were recognized from the CMAP database.

RESULTS

We identified 309 overlapping DEGs in the 2 tissue-types. Pathway analysis revealed that the DEGs were involved in cell cycle, DNA replication, and p53 signaling. PPI networks between overlapping DEGs showed 68 high-connectivity DEGs that were chosen as hub genes. The GEPIA database showed that the expression levels of RRM2, CDC45, GINS2, HELLS, KNTC1, MCM2, MYBL2, PCNA, RAD54 L, RFC4, RFC5, TK1, TOP2A, and TYMS in CC tissues were significantly different from those in the healthy tissues and were significantly relevant to the OS of CC. We found 10 small molecules from the CMAP database that could change the trend of gene expression in CC tissues, including piperlongumine and chrysin.

CONCLUSIONS

The 14 DEGs identified in this study could serve as novel prognosis biomarkers for the detection and forecasting of CC. Small molecule drugs like piperlongumine and chrysin could be potential therapeutic drugs for CC treatment.

Anti-cancer effects of polyphenols via targeting p53 signaling pathway: updates and future directions

The anticancer effects of polyphenols are ascribed to several signaling pathways including the tumor suppressor gene tumor protein 53 (p53). Expression of endogenous p53 is silent in various types of cancers. A number of polyphenols from a wide variety of dietary sources could upregulate p53 expression in several cancer cell lines through distinct mechanisms of action. The aim of this review is to focus the significance of p53 signaling pathways and to provide molecular intuitions of dietary polyphenols in chemoprevention by monitoring p53 expression that have a prominent role in tumor suppression.

The Effects of the Dietary and Nutrient Intake on Gynecologic Cancers

The contribution of diet to cancer risk has been considered to be higher in advanced countries than in developing countries. In this paper, I review the current issues (a review of the relevant literature), and the effects of the dietary and nutrient intake on three types of gynecologic cancer (cervical, endometrial and ovarian cancers). In cervical cancer, the most important roles of diet/nutrition in relation to cancer are prophylaxis and countermeasures against human papillomavirus (HPV) infection. The main preventive and reductive factors of cervical cancer are antioxidants, such as vitamin A, C, D and E, carotenoids, vegetables and fruits. These antioxidants may have different abilities to intervene in the natural history of diseases associated with HPV infection. For endometrial cancer, the increase in peripheral estrogens as a result of the aromatization of androgens to estrogens in adipose tissue in obese women and insulin resistance are risk factors. Thus, we must mainly take care to avoid the continuous intake of fat energy and sugar. In ovarian cancer, the etiology has not been fully understood. To the best of our knowledge, the long-term consumption of pro-inflammatory foods, including saturated fat, carbohydrates and animal proteins is a risk factor. The intake of acrylamide is also a risk factor for both endometrial and ovarian cancer. Most papers have been epidemiological studies. Thus, further research using in vitro and in vivo approaches is needed to clarify the effects of the dietary and nutrient intake in detail.

Oxidative stress in cervical cancer pathogenesis and resistance to therapy

Cervical cancer (CC) is one of the most common cancers among females, and it is most notable in developing countries. The exact etiology of CC is poorly understood; but, smoking, oral contraceptives, immunosuppression, and infection with human papillomavirus (HPV) may increase the risk of CC. There is also an association between CC and oxidative stress. Oxidative stress is caused by a disturbed oxidant-antioxidant balance in favor of the former, leading to an excessive generation of free radicals, particularly reactive oxygen species (ROS), and subsequently to biological damages. Thus, redox enzymatic and nonenzymatic regulators are required to maintain the redox homeostasis. Dysregulated antioxidants system and the pathogenic role of oxidative stress in CC have been investigated in several clinical and preclinical studies. In this study, we reviewed studies that have addressed the cross-talk between oxidative stress and CC pathogenesis and resistance to therapy.

An Olive Leaf Extract Rich in Polyphenols Promotes Apoptosis in Cervical Cancer Cells by Upregulating p21Cip/WAF1 Gene Expression

Most of the common drugs used to treat the cervical cancer, which main etiological factor is the HPV infection, cause side effects and intrinsic/acquired resistance to chemotherapy. In this study we investigated whether an olive leaf extract (OLE), rich in polyphenols, was able to exert anti-tumor effects in human cervical cancer cells (HeLa). MTT assay results showed a reduction of HeLa cells viability OLE-induced, concomitantly with a gene and protein down-regulation of Cyclin-D1 and an up-regulation of p21, triggering intrinsic apoptosis. OLE reduced NFkB nuclear translocation, which constitutive activation, stimulated by HPV-oncoproteins, promotes cancer progression and functional studies revealed that OLE activated p21^Cip/WAF1 in a transcriptional-dependent-manner, by reducing the nuclear recruitment of NFkB on its responsive elements. Furthermore, OLE treatment counteracted epithelial-to-mesenchymal-transition and inhibited anchorage-dependent and -independent cell growth EGF-induced. Finally, MTT assay results revealed that OLE plus Cisplatin strengthened the reduction of cells viability Cisplatin-induced, as OLE inhibited NFkB, AkT and MAPK pathways, all involved in Cisplatin chemoresistance. In conclusion, we demonstrated that in HeLa cells OLE exerts pro-apoptotic effects, elucidating the molecular mechanism and that OLE could mitigate Cisplatin chemoresistance. Further studies are needed to explore the potential coadiuvant use of OLE for cervical cancer treatment.

Suppressive Effects of EGCG on Cervical Cancer

Cervical cancer is the fourth most common gynecological cancer worldwide. Although prophylactic vaccination presents the most effective method for cervical cancer prevention, chemotherapy is still the primary invasive intervention. It is urgent to exploit low-toxic natural anticancer drugs on account of high cytotoxicity and side-effects of conventional agents. As a natural product, (-)-epigallocatechingallate (EGCG) has abilities in anti-proliferation, anti-metastasis and pro-apoptosis of cervical cancer cells. Moreover, EGCG also has pharmaceutical synergistic effects with conventional agents such as cisplatin (CDDP) and bleomycin (BLM). The underlying mechanisms of EGCG suppressive effects on cervical cancer are reviewed in this article. Further research directions and ambiguous results are also discussed.

Combined treatment with acetazolamide and cisplatin enhances chemosensitivity in laryngeal carcinoma Hep-2 cells

The aim of the present study was to determine whether acetazolamide (Ace) treatment enhances the chemosensitivity of Hep-2 laryngeal cells to cisplatin (Cis). At the logarithmic growth phase, Hep-2 cells were treated with Ace, Cis or both, and cell viability was detected using an MTT assay. The degree of apoptosis was detected using flow cytometry. Expression levels of apoptosis-related proteins, including BCL2 apoptosis regulator (bcl-2), BCL2 associated X (bax) and caspase-3, and of proliferation-related proteins, including proliferating cell nuclear antigen (PCNA) and tumor protein p53 (P53), were detected using western blotting. mRNA expression levels of aquaporin-1 (AQP1) in each group were detected using reverse transcription-polymerase chain reaction. Compared with the drugs used alone, treatment with both Ace and Cis displayed synergistic effects on the growth inhibition and apoptosis induction in Hep-2 cells. The Ace/Cis combination decreased the expression of PCNA but increased the expression of p53. In addition, the combination treatment decreased the ratio of bcl-2/bax and increased the expression of caspase-3, as well as decreased the expression of AQP1. These results demonstrated that the combined use of Ace and Cis enhanced the chemosensitivity of laryngeal carcinoma cells.

Proteomic Analysis of Normal and Cancer Cervical Cell Lines Reveals Deregulation of Cytoskeleton-associated Proteins

BACKGROUND

Both HPV-positive and -negative cervical cancers are primarily associated with features of cell cycle and cytoskeletal disruption; however, the actual biological processes affected remain elusive. To this end, we systematically characterized the intracellular proteomic profiles of four distinct and informative cervical cell lines.

MATERIALS AND METHODS

Cell extracts from a normal cervical (HCK1T) and three cervical cancer cell lines, one HPV-negative (C33A), and two HPV-positive, SiHa (HPV16+) and HeLa (HPV18+), were analyzed by 2-dimensional electrophoresis and differentially expressed proteins were identified by MALDI-TOF mass spectrometry, while differential expression was confirmed by western blot analysis.

RESULTS

In total, 113 proteins were found differentially expressed between the normal and the cervical cancer lines. Bioinformatics analysis revealed the actin cytoskeleton signaling pathway to be significantly affected, while up-regulation of cofilin-1, an actin depolymerizing factor, was documented and further validated by western blotting. Furthermore, two-way comparisons among the four cell lines, revealed a set of 18 informative differentially expressed proteins.

CONCLUSION

These novel identified proteins provide the impetus for further functional studies to dissect the mechanisms operating in the two distinct pathways of cervical carcinogenesis.

Synergistic effects of cisplatin-caffeic acid induces apoptosis in human cervical cancer cells via the mitochondrial pathways

Cervical cancer (CxCa) is a major health problem globally and is associated with the presence of human papillomavirus infection. Cisplatin (CDDP) is a platinum-based chemotherapeutic agent. Owing to its side effects and drug-resistance, novel anticancer agents with lower toxicity, including caffeic acid (CFC), are of interest. However, the effects of CDDP and CFC in combination are, to the best of our knowledge, uninvestigated. The present study investigated the effectiveness of CDDP and CFC in combination and its mechanism of action on four human cervical cancer cell lines, which were compared with the Chlorocebus sabaeus normal kidney Vero cell line. Cell viability was evaluated using a sulforhodamine B assay. Caspase-Glo assay kits, measuring the activity of caspases-3, -7, -8 and -9, were used to detect caspase activation in HeLa and CaSki cell lines in response to CDDP and CFC in combination. The results revealed that CDDP and CFC alone reduced the proliferation of HeLa, CaSki, SiHa and C33A cell lines. Treatment with CFC exhibited no significant cytotoxicity towards Vero cells. In addition, CDDP-CFC significantly inhibited cell growth of HeLa and CaSki cell lines. In HeLa and CaSki cell lines, a combination index <1 for CDDP and CFC indicated the synergistic growth inhibition; the combination of the two also significantly increased expression of caspase-3, -7 and -9. In conclusion, CFC may be a candidate anticancer agent that, when use in combination, may increase the therapeutic efficacy of CDDP.

Cariporide Enhances the DNA Damage and Apoptosis in Acid-tolerable Malignant Mesothelioma H-2452 Cells

The Na+/H+ exchanger is responsible for maintaining the acidic tumor microenvironment through its promotion of the reabsorption of extracellular Na+ and the extrusion of intracellular H+. The resultant increase in the extracellular acidity contributes to the chemoresistance of malignant tumors. In this study, the chemosensitizing effects of cariporide, a potent Na+/H+-exchange inhibitor, were evaluated in human malignant mesothelioma H-2452 cells preadapted with lactic acid. A higher basal level of phosphorylated (p)-AKT protein was found in the acid-tolerable H-2452AcT cells compared with their parental acid-sensitive H-2452 cells. When introduced in H-2452AcT cells with a concentration that shows only a slight toxicity in H-2452 cells, cariporide exhibited growth-suppressive and apoptosis-promoting activities, as demonstrated by an increase in the cells with pyknotic and fragmented nuclei, annexin V-PE(+) staining, a sub-G0/G1 peak, and a G2/M phase-transition delay in the cell cycle. Preceding these changes, a cariporide-induced p-AKT down-regulation, a p53 up-regulation, an ROS accumulation, and the depolarization of the mitochondrial-membrane potential were observed. A pretreatment with the phosphatidylinositol-3-kinase (PI3K) inhibitor LY294002 markedly augmented the DNA damage caused by the cariporide, as indicated by a much greater extent of comet tails and a tail moment with increased levels of the p-histone H2A.X, p-ATMSer1981, p-ATRSer428, p-CHK1Ser345, and p-CHK2Thr68, as well as a series of pro-apoptotic events. The data suggest that an inhibition of the PI3K/AKT signaling is necessary to enhance the cytotoxicity toward the acid-tolerable H-2452AcT cells, and it underlines the significance of proton-pump targeting as a potential therapeutic strategy to overcome the acidic-microenvironment-associated chemotherapeutic resistance.

Mechanisms and therapeutic prospects of polyphenols as modulators of the aryl hydrocarbon receptor

Polyphenolic AhR modulators displayed concentration-, XRE-, gene-, species- and cell-specific agonistic/antagonistic activity.

Bothrops jararaca and Bothrops erythromelas Snake Venoms Promote Cell Cycle Arrest and Induce Apoptosis via the Mitochondrial Depolarization of Cervical Cancer Cells

Bothrops jararaca (BJ) and Bothrops erythromelas (BE) are viper snakes found in South-Southeast and Northeast regions of Brazil, respectively. Snake venoms are bioactive neurotoxic substances synthesized and stored by venom glands, with different physiological and pharmacological effects, recently suggesting a possible preference for targets in cancer cells; however, mechanisms of snakes have been little studied. Here, we investigated the mechanism responsible for snake crude venoms toxicity in cultured cervical cancer cells SiHa and HeLa. We show that BJ and BE snake crude venoms exert cytotoxic effects to these cells. The percentage of apoptotic cells and cell cycle analysis and cell proliferation were assessed by flow cytometry and MTT assay. Detection of mitochondrial membrane potential (Rhodamine-123), nuclei morphological change, and DNA fragmentation were examined by staining with DAPI. The results showed that both the BJ and BE venoms were capable of inhibiting tumor cell proliferation, promoting cytotoxicity and death by apoptosis of target SiHa and HeLa cells when treated with BJ and BE venoms. Furthermore, data revealed that both BJ venoms in SiHa cell promoted nuclear condensation, fragmentation, and formation of apoptotic bodies by DAPI assay, mitochondrial damage by Rhodamine-123, and cell cycle block in the G1-G0 phase. BJ and BE venoms present anticancer potential, suggesting that both Bothrops venoms could be used as prototypes for the development of new therapies.

Proteasome inhibition mediates p53 reactivation and anti-cancer activity of 6-gingerol in cervical cancer cells

Human papilloma virus (HPV) expressing E6 and E7 oncoproteins, is known to inactivate the tumor suppressor p53 through proteasomal degradation in cervical cancers. Therefore, use of small molecules for inhibition of proteasome function and induction of p53 reactivation is a promising strategy for induction of apoptosis in cervical cancer cells. The polyphenolic alkanone, 6-Gingerol (6G), present in the pungent extracts of ginger (Zingiber officinale Roscoe) has shown potent anti-tumorigenic and pro-apoptotic activities against a variety of cancers. In this study we explored the molecular mechanism of action of 6G in human cervical cancer cells in vitro and in vivo. 6G potently inhibited proliferation of the HPV positive cervical cancer cells. 6G was found to: (i) inhibit the chymotrypsin activity of proteasomes, (ii) induce reactivation of p53, (iii) increase levels of p21, (iv) induce DNA damage and G2/M cell cycle arrest, (v) alter expression levels of p53-associated apoptotic markers like, cleaved caspase-3 and PARP, and (vi) potentiate the cytotoxicity of cisplatin. 6G treatment induced significant reduction of tumor volume, tumor weight, proteasome inhibition and p53 accumulation in HeLa xenograft tumor cells in vivo. The 6G treatment was devoid of toxic effects as it did not affect body weights, hematological and osteogenic parameters. Taken together, our data underscores the therapeutic and chemosensitizing effects of 6G in the management and treatment of cervical cancer.

Dietary flavonoid derivatives enhance chemotherapeutic effect by inhibiting the DNA damage response pathway

Flavonoids are the most common group of polyphenolic compounds and abundant in dietary fruits and vegetables. Diet high in vegetables or dietary flavonoid supplements is associated with reduced mortality rate for patients with breast cancer. Many studies have been proposed for mechanisms linking flavonoids to improving chemotherapy efficacy in many types of cancers, but data on this issue is still limited. Herein, we report on a new mechanism through which dietary flavonoids inhibit DNA damage checkpoints and repair pathways. We found that dietary flavonoids could inhibit Chk1 phosphorylation and decrease clonogenic cell growth once breast cancer cells receive ultraviolet irradiation, cisplatin, or etoposide treatment. Since the ATR-Chk1 pathway mainly involves response to DNA replication stress, we propose that flavonoid derivatives reduce the side effect of chemotherapy by improving the sensitivity of cycling cells. Therefore, we propose that increasing intake of common dietary flavonoids is beneficial to breast cancer patients who are receiving DNA-damaging chemotherapy, such as cisplatin or etoposide-based therapy.

The Role of Natural Polyphenols in the Prevention and Treatment of Cervical Cancer-An Overview

Cervical cancer represents the second leading cause of death for women worldwide. The importance of the diet and its impact on specific types of neoplasia has been highlighted, focusing again interest in the analysis of dietary phytochemicals. Polyphenols have shown a wide range of cellular effects: they may prevent carcinogens from reaching the targeted sites, support detoxification of reactive molecules, improve the elimination of transformed cells, increase the immune surveillance and the most important factor is that they can influence tumor suppressors and inhibit cellular proliferation, interfering in this way with the steps of carcinogenesis. From the studies reviewed in this paper, it is clear that certain dietary polyphenols hold great potential in the prevention and therapy of cervical cancer, because they interfere in carcinogenesis (in the initiation, development and progression) by modulating the critical processes of cellular proliferation, differentiation, apoptosis, angiogenesis and metastasis. Specifically, polyphenols inhibit the proliferation of HPV cells, through induction of apoptosis, growth arrest, inhibition of DNA synthesis and modulation of signal transduction pathways. The effects of combinations of polyphenols with chemotherapy and radiotherapy used in the treatment of cervical cancer showed results in the resistance of cervical tumor cells to chemo- and radiotherapy, one of the main problems in the treatment of cervical neoplasia that can lead to failure of the treatment because of the decreased efficiency of the therapy.

Molecular mechanisms of cisplatin resistance in cervical cancer

Patients with advanced or recurrent cervical cancer have poor prognosis, and their 1-year survival is only 10%–20%. Chemotherapy is considered as the standard treatment for patients with advanced or recurrent cervical cancer, and cisplatin appears to treat the disease effectively. However, resistance to cisplatin may develop, thus substantially compromising the efficacy of cisplatin to treat advanced or recurrent cervical cancer. In this article, we systematically review the recent literature and summarize the recent advances in our understanding of the molecular mechanisms underlying cisplatin resistance in cervical cancer.

Preparation of catechin extracts and nanoemulsions from green tea leaf waste and their inhibition effect on prostate cancer cell PC-3

Green tea is one of the most commonly consumed natural health beverages in Taiwan’s market, with the major functional component catechin being shown to possess several biological activities such as antioxidation, anticancer, and prevention of cardiovascular disease. The objectives of this study were to develop a high-performance liquid chromatography–mass spectrometry method to determine the variety and content of catechins in green tea leaf waste, a by-product obtained during processing of tea beverage. In addition, catechin nanoemulsion was prepared to study its inhibition effect on prostate cancer cell PC-3. Results showed that a total of eight catechin standards were separated within 25 minutes by using a Gemini C18 column and a gradient mobile phase of 0.1% formic acid (A) and acetonitrile (B) with flow rate at 1 mL/min, column temperature at 30°C, and detection wavelength at 280 nm. Among various extraction solvents, 50% ethanol generated the highest yield of total catechins from tea leaf waste, of which five catechins were identified and quantified. The catechin nanoemulsion was composed of catechin extract, lecithin, Tween 80, and deionized water in an appropriate proportion, with the mean particle size being 11.45 nm, encapsulation efficiency 88.1%, and zeta potential −66.3 mV. A high stability of catechin nanoemulsion was shown over a storage period of 120 days at 4°C. Both catechin extract and nanoemulsion could inhibit growth of PC-3 tumor cells, with the half maximal inhibitory concentration being 15.4 μg/mL and 8.5 μg/mL, respectively. The PC-3 cell cycle was arrested at S phase through elevation of P27 expression and decline of cyclin A, cyclin B, cyclin-dependent kinase 2, and cyclin-dependent kinase 1 expression. In addition, both catechin extract and nanoemulsion could induce apoptosis of PC-3 cells through decrease in B-cell lymphoma 2 (bcl-2) expression and increase in cytochrome c expression for activation of caspase-3, caspase-8, and caspase-9. Taken together, both caspase-dependent and caspase-independent pathways may be involved in apoptosis of PC-3 cells.

Alantolactone induces apoptosis of human cervical cancer cells via reactive oxygen species generation, glutathione depletion and inhibition of the Bcl-2/Bax signaling pathway

Alantolactone is the active ingredient in frankincense, and is extracted from the dry root of elecampane. It has a wide variety of uses, including as an insect repellent, antibacterial, antidiuretic, analgesic and anticancer agent. In addition, alantolactone induces apoptosis of human cervical cancer cells, however, its mechanism of action remains to be elucidated. Therefore, the present study investigated whether alantolactone was able to induce apoptosis of human cervical cancer cells, and its potential mechanisms of action were analyzed. Treatment of HeLa cells with alantolactone (0, 10, 20, 30, 40, 50 and 60 µM) for 12 h significantly inhibited growth in a dose-dependent manner. Cells treated with 30 µM of alantolactone for 0, 3, 6 and 12 h demonstrated marked induction of apoptosis in a time-dependent manner. Treatment of HeLa cells with 30 µM of alantolactone for 0, 3, 6 and 12 h significantly induced the generation of reactive oxygen species (ROS) and inhibited glutathione (GSH) production in HeLa cells in a dose-dependent manner. Alantolactone additionally markedly inhibited the Bcl-2/Bax signaling pathway in HeLa cells. Therefore, administration of alantolactone induced apoptosis of human cervical cancer cells via ROS generation, GSH depletion and inhibition of the Bcl-2/Bax signaling pathway.

Redox Control of Multidrug Resistance and Its Possible Modulation by Antioxidants

Clinical efficacy of anticancer chemotherapies is dramatically hampered by multidrug resistance (MDR) dependent on inherited traits, acquired defence against toxins, and adaptive mechanisms mounting in tumours. There is overwhelming evidence that molecular events leading to MDR are regulated by redox mechanisms. For example, chemotherapeutics which overrun the first obstacle of redox-regulated cellular uptake channels (MDR1, MDR2, and MDR3) induce a concerted action of phase I/II metabolic enzymes with a temporal redox-regulated axis. This results in rapid metabolic transformation and elimination of a toxin. This metabolic axis is tightly interconnected with the inducible Nrf2-linked pathway, a key switch-on mechanism for upregulation of endogenous antioxidant enzymes and detoxifying systems. As a result, chemotherapeutics and cytotoxic by-products of their metabolism (ROS, hydroperoxides, and aldehydes) are inactivated and MDR occurs. On the other hand, tumour cells are capable of mounting an adaptive antioxidant response against ROS produced by chemotherapeutics and host immune cells. The multiple redox-dependent mechanisms involved in MDR prompted suggesting redox-active drugs (antioxidants and prooxidants) or inhibitors of inducible antioxidant defence as a novel approach to diminish MDR. Pitfalls and progress in this direction are discussed.

Modulation of hexavalent chromium-induced genotoxic damage in peripheral blood of mice by epigallocatechin-3-gallate (EGCG) and its relationship to the apoptotic activity

This study was conducted to investigate the relationship between modulation of genotoxic damage and apoptotic activity in Hsd:ICR male mice treated with (-)-epigallocatechin-3-gallate (EGCG) and hexavalent chromium [Cr(VI)]. Four groups of 5 mice each were treated with (i) control vehicle only, (ii) EGCG (10 mg/kg) by gavage, (iii) Cr(VI) (20 mg/kg of CrO3) intraperitoneally (ip), and (iv) EGCG in addition to CrO3 (EGCG-CrO3). Genotoxic damage was evaluated by examining presence of micronucleated polychromatic erythrocytes (MN-PCE) obtained from peripheral blood of the caudal vein at 0, 24, 48, and 72 h after treatment. Induction of apoptosis and cell viability were assessed by differential acridine orange/ethidium bromide (AO/EB) staining. EGCG treatment produced no significant changes in frequency of MN-PCE. However, CrO3 treatment significantly increased number of MN-PCE at 24 and 48 h post injection. Treatment with EGCG prior to CrO3 injection decreased number of MN-PCE compared to CrO3 alone. The MN-PCE reduction was greater than when EGCG was administered ip. The frequency of early apoptotic cells was elevated at 48 h following EGCG, CrO3, or EGCG-CrO3 exposure, with highest levels observed in the combined treatment group, while the frequencies of late apoptotic cells and necrotic cells were increased only in EGCG-CrO3 exposure. Our findings support the view that EGCG is protective against genotoxic damage induced by Cr(VI) and that apoptosis may contribute to elimination of DNA-damaged cells (MN-PCE) when EGCG was administered prior to CrO3. Further, it was found that the route of administration of EGCG plays an important role in protection against CrO3-induced genotoxic damage.

Epigallocatechin gallate and mitochondria-A story of life and death

Epigallocatechin gallate (EGCG) is a flavonoid belonging to the chemical class of falvan-3-ols (catechins) esterified with gallic acid. It is the main catechin found in green tea (Camellia sinensis L.) accounting for about 50% of its total polyphenols. Extensive research performed in recent years has revealed that green tea demonstrates a wide range of positive biological activities against serious chronic diseases such as cardiovascular and neurodegenerative pathologies, cancer, metabolic syndrome and type 2 diabetes. These protective properties can be traced back to the potent antioxidant and anti-inflammatory activities of EGCG. Recent studies have suggested that it may exert its beneficial effects by modulating mitochondrial functions impacting mitochondrial biogenesis, bioenergetic control (ATP production and anabolism), alteration of the cell cycle, and mitochondria-related apoptosis. This review evaluates recent evidence on the ability of EGCG to exert critical influence on the above mentioned pathways.

Epigallocatechin-3-gallate suppresses alveolar epithelial cell apoptosis in seawater aspiration-induced acute lung injury via inhibiting STAT1-caspase-3/p21 associated pathway

The apoptosis of alveolar epithelial cells is important in seawater aspiration‑induced acute lung injury (ALI). The present study aimed to investigate whether epigallocatechin-3-gallate (EGCG) is able to suppress apoptosis in alveolar epithelial cells in seawater aspiration‑induced ALI in vivo and in vitro, and the possible mechanisms underlying it. The results indicated that seawater aspiration‑induced ALI in rats is accompanied by increased apoptosis in lung tissue cells and the expression of apoptosis‑associated proteins, caspase‑3 and p21. EGCG pretreatment significantly ameliorated seawater aspiration‑induced ALI. Furthermore, EGCG decreased seawater aspiration‑induced apoptosis and the expression of caspase‑3 and p21 in lung tissue cells. Seawater‑challenged A549 cells experienced increased apoptosis and elevated levels of phosphorylated‑signal transducer and activator of transcription 1 (P‑STAT1). EGCG pretreatment of the cells resulted in significantly decreased seawater‑induced apoptosis and lower levels of STAT1 and P‑STAT1 in A549 cells. This suggests that EGCG suppresses alveolar epithelial cell apoptosis in seawater aspiration‑induced ALI via inhibiting the STAT1-caspase-3/p21 associated pathway.

PLGA-encapsulated tea polyphenols enhance the chemotherapeutic efficacy of cisplatin against human cancer cells and mice bearing Ehrlich ascites carcinoma

The clinical success of the applicability of tea polyphenols awaits efficient systemic delivery and bioavailability. Herein, following the concept of nanochemoprevention, which uses nanotechnology for enhancing the efficacy of chemotherapeutic drugs, we employed tea polyphenols, namely theaflavin (TF) and epigallocatechin-3-gallate (EGCG) encapsulated in a biodegradable nanoparticulate formulation based on poly(lactide-co-glycolide) (PLGA) with approximately 26% and 18% encapsulation efficiency, respectively. It was observed that TF/EGCG encapsulated PLGA nanoparticles (NPs) offered an up to ~7-fold dose advantage when compared with bulk TF/EGCG in terms of exerting its antiproliferative effects and also enhanced the anticancer potential of cisplatin (CDDP) in A549 (lung carcinoma), HeLa (cervical carcinoma), and THP-1 (acute monocytic leukemia) cells. Cell cycle analysis revealed that TF/EGCG-NPs were more efficient than bulk TF/EGCG in sensitizing A549 cells to CDDP-induced apoptosis, with a dose advantage of up to 20-fold. Further, TF/EGCG-NPs, alone or in combination with CDDP, were more effective in inhibiting NF-κB activation and in suppressing the expression of cyclin D1, matrix metalloproteinase-9, and vascular endothelial growth factor, involved in cell proliferation, metastasis, and angiogenesis, respectively. EGCG and TF-NPs were also found to be more effective than bulk TF/EGCG in inducing the cleavage of caspase-3 and caspase-9 and Bax/Bcl2 ratio in favor of apoptosis. Further, in vivo evaluation of these NPs in combination with CDDP showed an increase in life span (P<0.05) in mice bearing Ehrlich's ascites carcinoma cells, with apparent regression of tumor volume in comparison with mice treated with bulk doses with CDDP. These results indicate that EGCG and TF-NPs have superior cancer chemosensitization activity when compared with bulk TF/EGCG.

Proteomic Analysis of Anticancer TCMs Targeted at Mitochondria

Traditional Chinese medicine (TCM) is a rich resource of anticancer drugs. Increasing bioactive natural compounds extracted from TCMs are known to exert significant antitumor effects, but the action mechanisms of TCMs are far from clear. Proteomics, a powerful platform to comprehensively profile drug-regulated proteins, has been widely applied to the mechanistic investigation of TCMs and the identification of drug targets. In this paper, we discuss several bioactive TCM products including terpenoids, flavonoids, and glycosides that were extensively investigated by proteomics to illustrate their antitumor mechanisms in various cancers. Interestingly, many of these natural compounds isolated from TCMs mostly exert their tumor-suppressing functions by specifically targeting mitochondria in cancer cells. These TCM components induce the loss of mitochondrial membrane potential, the release of cytochrome c, and the accumulation of ROS, initiating apoptosis cascade signaling. Proteomics provides systematic views that help to understand the molecular mechanisms of the TCM in tumor cells; it bears the inherent limitations in uncovering the drug-protein interactions, however. Subcellular fractionation may be coupled with proteomics to capture and identify target proteins in mitochondria-enriched lysates. Furthermore, translating mRNA analysis, a new technology profiling the drug-regulated genes in translatome level, may be integrated into the systematic investigation, revealing global information valuable for understanding the action mechanism of TCMs.

Characteristic features of cytotoxic activity of flavonoids on human cervical cancer cells

Cervical cancer is the most common gynecologic malignancy worldwide and development of new therapeutic strategies and anticancer agents is an urgent priority. Plants have remained an important source in the search for novel cytotoxic compounds and several polyphenolic flavonoids possess antitumor properties. In this review article, data about potential anticarcinogenic activity of common natural flavonoids on various human cervical cancer cell lines are compiled and analyzed showing perspectives for the use of these secondary metabolites in the treatment of cervical carcinoma as well as in the development of novel chemotherapeutic drugs. Such anticancer effects of flavonoids seem to differentially depend on the cellular type and origin of cervical carcinoma creating possibilities for specific targeting in the future. Besides the cytotoxic activity per se, several flavonoids can also contribute to the increase in efficacy of conventional therapies rendering tumor cells more sensitive to standard chemotherapeutics and irradiation. Although the current knowledge is still rather scarce and further studies are certainly needed, it is clear that natural flavonoids may have a great potential to benefit cervical cancer patients.

The green tea catechin epigallocatechin gallate induces cell cycle arrest and shows potential synergism with cisplatin in biliary tract cancer cells

Background

The green tea catechin epigallocatechin gallate (EGCG) was shown to effectively inhibit tumor growth in various types of cancer including biliary tract cancer (BTC). For most BTC patients only palliative therapy is possible, leading to a median survival of about one year. Chemoresistance is a major problem that contributes to the high mortality rates of BTC. The aim of this study was to investigate the cytotoxic effect of EGCG alone or in combination with cisplatin on eight BTC cell lines and to investigate the cellular anti-cancer mechanisms of EGCG.

Methods

The effect of EGCG treatment alone or in combination with the standard chemotherapeutic cisplatin on cell viability was analyzed in eight BTC cell lines. Additionally, we analyzed the effects of EGCG on caspase activity, cell cycle distribution and gene expression in the BTC cell line TFK-1.

Results

EGCG significantly reduced cell viability in all eight BTC cell lines (p < 0.05 or p < 0.01, respectively, for most cell lines and EGCG concentrations > 5 μM). Combined EGCG and cisplatin treatment showed a synergistic cytotoxic effect in five cell lines and an antagonistic effect in two cell lines. Furthermore, EGCG reduced the mRNA levels of various cell cycle-related genes, while increasing the expression of the cell cycle inhibitor p21 and the apoptosis-related death receptor 5 (p < 0.05). This observation was accompanied by an increase in caspase activity and cells in the sub-G1 phase of the cell cycle, indicating induction of apoptosis. EGCG also induced a down-regulation of expression of stem cell-related genes and genes that are associated with an aggressive clinical character of the tumor, such as cd133 and abcg2.

Conclusions

EGCG shows various anti-cancer effects in BTC cell lines and might therefore be a potential anticancer drug for future studies in BTC. Additionally, EGCG displays a synergistic cytotoxic effect with cisplatin in most tested BTC cell lines.

Graphical abstract

Enhancement of Cisplatin sensitivity in human cervical cancer: epigallocatechin-3-gallate

Cisplatin is one of the effective chemotherapeutics in the treatment of several types of cancers. However, in addition to the efforts against to its toxicity, the amelioration of cisplatin sensitivity is an important point in treatment of cervical cancer. To do so, additional substances such as epigallocatechin gallate (EGCG), a polyphenol in green tea, have been used in combination with chemotherapeutics. We aimed to investigate the possible molecular pathways to potentiate cervical cancer cell (HeLa) growth inhibition by combination therapy of cisplatin and EGCG. HeLa cells were treated with EGCG (25 μM), cisplatin (250 nM), and their combination for 24 h. Cell viability was determined by MTS Assay. We analyzed the expressions of NF-κB p65, COX-2, Nrf2, HO-1, p-mTOR, p-p70S6K1, p-4E-BP1, and p-Akt by Western blot analysis. Herein, we have demonstrated that EGCG works synergistic with cisplatin in inhibiting growth of cervical cancer cells. EGCG improved efficacy of cisplatin treatment in HeLa cells by regulating NFκB p65, COX-2, p-Akt, and p-mTOR pathways, whereas it increased the expression levels of Nrf2/HO-1 in combined therapy. Our observations revealed that EGCG increases the sensitization of cisplatin to cervical cancer cells by inhibiting cell survival and inducing apoptosis.

pecific nutrient combination effects on tax, NF- κB and MMP-9 in human T-cell lymphotropic virus -1 positive malignant T-lymphocytes

BACKGROUND

Adult T-cell Leukemia (ATL) is a disease with no known cure. The disease manifests itself as an aggressive proliferation of CD4+ cells with the human T-cell Lymphotropic virus type 1 (HTLV-1). The leukemogenesis of the virus is mainly attributed to the viral oncoprotein. Tax activates the Nuclear Factor kappa B (NF-κB) which stimulates the activity and expression of the matrix metalloproteinase-9 (MMP-9). The objective of this study was to investigate the efficacy of a specific nutrient synergy (SNS) on proliferation, Tax expression, NF-κB levels as well as on MMP-9 activity and expression both at the transcriptional and translational levels in two HTLV-1 positive cell lines, HuT-102 and C91-PL at 48h and 96h of incubation. Cytotoxicity of Epigallocatechin-3-gallate (EGCG) was assayed using CytoTox 96 Non-radioactive and proliferation was measured using Cell Titer96TM Nonradioactive Cell Proliferation kit (MTT- based assay). Enzyme linked immunosorbant assay (ELISA) and electrophoretic mobility shift assay (EMSA) were used to assess the effect of SNS on NF-κB mobility. Zymography was used to determine the effects of SNS on the activity and secretion of MMP-9. The expression of MMP-9 was done using RT-PCR at the translational level and Immunoblotting at the transcriptional level.

RESULTS

A significant inhibition of proliferation was seen in both cell lines starting at a concentration of 200μg/ml and in a dose dependent manner. SNS induced a dose dependent decrease in Tax expression, which was paralleled by a down-regulation of the nuclearization of NF-κB. This culminated in the inhibition of the activity of MMP-9 and their expression both at the transcriptional and translational levels.

CONCLUSIONS

The results of this study indicate that a specific nutrient synergy targeted multiple levels pertinent to the progression of ATL. Its activity was mediated through the NF-κB pathway, and hence has the potential to be integrated in the treatment of this disease as a natural potent anticancer agent.

Gallic acid: prospects and molecular mechanisms of its anticancer activity

Gallic acid (GA) is a phenolic acid found in many dietary substances. It is a natural compound found in gallnuts, sumac, witch-hazel, clove, tealeaves, oak bark, sundew and other plants. Edibles like blackberry, hot chocolate, common walnut and Indian gooseberry contain GA.

The anti-cancer activity of green tea, coffee and cocoa extracts on human cervical adenocarcinoma HeLa cells depends on both pro-oxidant and anti-proliferative activities of polyphenols

Thein vitroanti-cervical cancer potency of tested polyphenol extracts is exhibited in the following order: green tea > coffee > cocoa, with only green tea showing both pro-oxidative and anti-proliferative action.

Phytochemical modulators of mitochondria: the search for chemopreventive agents and supportive therapeutics

Mitochondria are crucially important for maintaining not only the energy homeostasis, but the proper cellular functions in a general sense. Impairment of mitochondrial functions is observed in a broad variety of pathological states such as neoplastic transformations and cancer, neurodegenerative diseases, metabolic disorders and chronic inflammation. Currently, in parallel to the classical drug design approaches, there is an increasing interest in the screening for natural bioactive substances, mainly phytochemicals, in order to develop new therapeutic solutions for the mentioned pathologies. Dietary phytochemicals such as resveratrol, curcumin and sulforaphane are very well tolerated and can effectively complement classical pharmacological therapeutic regimens. In this paper we disscuss the effect of the chosen phytochemicals (e.g., resveratrol, curcumin, sulforaphane) on various aspects of mitochondrial biology, namely mitochondrial biogenesis, membrane potential and reactive oxygen species production, signaling to and from the nucleus and unfolded protein response.

Resveratrol sensitizes selectively thyroid cancer cell to 131-iodine toxicity

Background. In this study, the radiosensitizing effect of resveratrol as a natural product was investigated on cell toxicity induced by (131)I in thyroid cancer cell. Methods. Human thyroid cancer cell and human nonmalignant fibroblast cell (HFFF2) were treated with (131)I and/or resveratrol at different concentrations for 48 h. The cell proliferation was measured by determination of the percent of the survival cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results. Findings of this study show that resveratrol enhanced the cell death induced by (131)I on thyroid cancer cell. Also, resveratrol exhibited a protective effect on normal cells against (131)I toxicity. Conclusion. This result indicates a promising effect of resveratrol on improvement of cellular toxicity during iodine therapy.

A RXR ligand 6-OH-11-O-hydroxyphenanthrene with antitumour properties enhances (-)-epigallocatechin-3-gallate activity in three human breast carcinoma cell lines

(−)-Epigallocatechin-3-gallate (EGCG) and chemotherapeutic agents cotreatment can improve cytotoxicity against cancer cells. We showed that EGCG and the rexinoid 6-OH-11-O-hydroxyphenanthrene (IIF), given together, were cytotoxic toward MCF-7, MCF-7TAM, and MDA-MB-231, three breast carcinoma cell lines showing different molecular characteristics. Cell growth arrest and apoptosis were greater after EGCG and IIF cotreatment than after individual administration. Cytotoxicity was related to upregulation of 67-kDa laminin receptor (LR67), one of the principal molecular targets of EGCG, and activation of the nuclear retinoic X receptors (RXRs) pathway. Furthermore, the transcription factor Forkhead box O3 (Foxo3a), a protein able to trigger apoptosis through upregulation of genes necessary for cell death, was activated. EGCG and IIF cotreatment produced a significant nuclear import of Foxo3a from the cytoplasm in MCF-7, MCF-7TAM, and MDA-MB-231 cells. In MCF-7TAM cells only, Foxo3a nuclear localization was associated with p473AKT downregulation. For the first time we showed that when EGCG and IIF, two harmless molecules, were given together, they might increase cytotoxicity in three breast carcinoma cell lines, two of them being representative of poorly responsive breast carcinoma types.

Cytotoxic effects of Euterpe oleracea Mart. in malignant cell lines

Background

Euterpe oleracea Mart., a plant from the Amazon region, is commonly known as açaí or juçara; it has high nutritional value and elevated levels of lipids, proteins, and minerals. Açaí is an abundant and much consumed fruit by the Amazon local population, and studies have demonstrated that it is rich in phytochemicals with antioxidant, anti-inflammatory, and anticancer activities. Therefore, the aim of this study was to test this plant for anticancer activity in different human malignant cell lines.

Methods

Cell lines derived from breast and colorectal adenocarcinomas were treated with 10, 20, and 40 μg/mL of bark, seed, and total açaí fruit hydroalcoholic extracts for 24 and 48 h. After treatment, cell viability was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays, and cell morphological features were observed by light and transmission electron microscopy. The type of cell death was also evaluated. The data were analyzed statistically by one-way analysis of variance (ANOVA), followed by Dunnett’s or Tukey’s post hoc tests, as appropriate.

Results

We observed that of all the cell lines tested, MCF-7 was the only line that responded to açaí treatment. The extracts caused significant reduction (p < 0.01) in cell viability and altered cell morphological features by inducing the appearance of autophagic vacuoles, as observed by transmission electron microscopy. Furthermore, increased expression of LC3BII, a protein marker of autophagosome formation, was observed by western blotting. Caspase Glo™ assays and morphologic observations by DAPI nuclear staining and transmission electron microscopy did not indicate any apoptotic events.

Conclusions

The present study demonstrated that açaí possesses antitumorigenic potential in the MCF-7 cell line. Further studies are needed to identify the compound (s) responsible for this cytotoxic activity and the molecular target in the cell. This discovery of the anticancer potential of açaí may help in the development of chemopreventive drugs and may have therapeutic effects in the treatment of breast cancer.

Ginsenoside Rg3 Inhibits Constitutive Activation of NF-κB Signaling in Human Breast Cancer (MDA-MB-231) Cells: ERK and Akt as Potential Upstream Targets

Ginsenoside Rg3, one of the major ingredients of heat-processed ginseng, has been reported to inhibit the growth of various cancer cells. We previously reported that Rg3 inhibited the proliferation and induced apoptosis of breast cancer (MDA-MB-231) cells. In the present study, we have explored the mechanism underlying the anti-proliferative and proapoptotic effects of Rg3 in MDA-MB-231 cells, which have constitutively activated NF-κB and the mutant form of p53. Rg3 inhibited DNA binding and transcriptional activity of NF-κB and these effects were attributable to its suppression of IKKβ activity, degradation of IκBα and subsequent nuclear translocation of the p65 subunit of NF-κB. Similarly, the constitutive activation of ERK and Akt through phosphorylation was gradually reduced in MDA-MB-231 cells treated with Rg3. The pharmacological inhibitors of these kinases both U0126 (MEK1/2 inhibitor) and LY294002 (PI3K inhibitor) abrogated the NF-κB DNA binding activity in MDA-MB-231 cells. In addition, Rg3 treatment lowered the levels of the mutant p53 in concentration- and time-dependent manners. Rg3 also increased the association between p53 and its negative regulator Mdm2 in MDA-MB-231 cells. These findings suggest that Rg3 induced apoptosis in MDA-MB-231 cells, which is mediated by blocking NF-κB signaling via inactivation of ERK and Akt as well as destabilization of mutant p53.

The effects of bioactive compounds from plant foods on mitochondrial function: a focus on apoptotic mechanisms

Mitochondria are essential organelles for cellular integrity and functionality maintenance and their imparement is implicated in the development of a wide range of diseases, including metabolic, cardiovascular, degenerative and hyperproliferative pathologies. The identification of different compounds able to interact with mitochondria for therapeutic purposes is currently becoming of primary importance. Indeed, it is well known that foods, particularly those of vegetable origin, present several constituents with beneficial effects on health. This review summarizes and updates the most recent findings concerning the mechanisms through which different dietary compounds from plant foods affect mitochondria functionality in healthy and pathological in vitro and in vivo models, paying particular attention to the pathways involved in mitochondrial biogenesis and apoptosis.

Tea consumption and lung cancer risk: a meta-analysis of case-control and cohort studies

OBJECTIVE

Recent epidemiologic studies, especially cohort and case-control studies, have yielded inconsistent findings regarding the association between tea consumption and risk for lung cancer. The aim of this study was to assess a potential relationship between tea consumption and the incidence of lung cancer worldwide.

METHODS

A systematic literature search of PubMed, Web of Science, the Cochrane Library, Google Scholar, the Chinese Biomedical Database, and Wanfang Database was conducted from 1966 to January 2014 by two investigators. All cohort studies and case-control studies that evaluated the association of tea and lung cancer were included. Summary relative risks (RR) and the corresponding 95% confidence intervals (CIs) were calculated using a random-effects model. Quality assessments were performed using the Newcastle-Ottawa Scale. Heterogeneity was assessed using the Q and I(2) tests, and the source of heterogeneity was detected by meta-regression analysis. Publication bias was evaluated with Egger's regression symmetry test. Subgroup analyses and sensitivity analysis were performed.

RESULTS

Thirty-eight lung cancer studies (26 case-control studies and 12 cohort studies) with 59,041 cases and 396,664 controls were included. Overall tea consumption was significantly associated with decreased risk for lung cancer (RR, 0.78; 95% CI, 0.70-0.87). Subgroup analyses showed that tea consumption was associated with reduced risk for lung cancer in women (RR, 0.76; 95% CI, 0.62-0.93), case-control studies (RR 0.72; 95% CI 0.63-0.83), Western studies (RR, 0.85; 95% CI, 0.75-0.97), and studies in China and Japan (RR, 0.74; 95% CI, 0.62-0.88). Both green tea (RR, 0.75; 95% CI, 0.62-0.91) and black tea (RR, 0.82; 95% CI, 0.71-0.94) were significantly associated with reduced lung cancer risk. No significant association was found in men or in cohort studies.

CONCLUSION

Tea consumption may offer some protection against lung cancer.

Emerging biological treatments for uterine cervical carcinoma

Cervical cancer is the third most common cancer worldwide, and the development of new diagnosis, prognostic, and treatment strategies is a major interest for public health. Cisplatin, in combination with external beam irradiation for locally advanced disease, or as monotherapy for recurrent/metastatic disease, has been the cornerstone of treatment for more than two decades. Other investigated cytotoxic therapies include paclitaxel, ifosfamide and topotecan, as single agents or in combination, revealing unsatisfactory results. In recent years, much effort has been made towards evaluating new drugs and developing innovative therapies to treat cervical cancer. Among the most investigated molecular targets are epidermal growth factor receptor and vascular endothelial growth factor (VEGF) signaling pathways, both playing a critical role in cervical cancer development. Studies with bevacizumab or VEGF receptor tyrosine kinase have given encouraging results in terms of clinical efficacy, without adding significant toxicity. A great number of other molecular agents targeting critical pathways in cervical malignant transformation are being evaluated in preclinical and clinical trials, reporting preliminary promising data.

In the current review, we discuss novel therapeutic strategies which are being investigated for the treatment of advanced cervical cancer.

Antigenotoxic and apoptotic activity of green tea polyphenol extracts on hexavalent chromium-induced DNA damage in peripheral blood of CD-1 mice: analysis with differential acridine orange/ethidium bromide staining

This study was conducted to investigate the modulating effects of green tea polyphenols on genotoxic damage and apoptotic activity induced by hexavalent chromium [Cr (VI)] in CD-1 mice. Animals were divided into the following groups: (i) injected with vehicle; (ii) treated with green tea polyphenols (30 mg/kg) via gavage; (iii) injected with CrO₃ (20 mg/kg) intraperitoneally; (iv) treated with green tea polyphenols in addition to CrO₃. Genotoxic damage was evaluated by examining micronucleated polychromatic erythrocytes (MN-PCEs) obtained from peripheral blood at 0, 24, 48, and 72 h after treatment. Induction of apoptosis and cell viability were assessed by differential acridine orange/ethidium bromide (AO/EB) staining. Treatment of green tea polyphenols led to no significant changes in the MN-PCEs. However, CrO₃ treatment significantly increased MN-PCEs at 24 and 48 h after injection. Green tea polyphenols treatment prior to CrO₃ injection led to a decrease in MN-PCEs compared to the group treated with CrO₃ only. The average of apoptotic cells was increased at 48 h after treatment compared to control mice, suggesting that apoptosis could contribute to eliminate the DNA damaged cells induced by Cr (VI). Our findings support the proposed protective effects of green tea polyphenols against the genotoxic damage induced by Cr (VI).