The Effects of Resveratrol, Gallic Acid, and Piperine on the Expression of miR-17, miR-92b, miR-181a, miR-222, BAX, BCL-2, MCL-1, WT1, c-Kit, and CEBPA in Human Acute Myeloid Leukemia Cells and Their Roles in Apoptosis

MicroRNAs (miRs) play a crucial role in the leukemogenesis and the prognosis of acute myeloid leukemia (AML). This study investigated the therapeutic effects of resveratrol, gallic acid, and piperine as natural anticancer agents on the HL-60 cell line and their roles in apoptosis. In this experimental study, quantitative analysis of miRs, including miR-17, miR-92b, miR-181a, and miR-222, were performed in 150 newly diagnosed patients with AML by real-time PCR assay. HL-60 cell viability as well as the expression of miRs, BAX, BCL-2, MCL-1, WT1, c-Kit, and CEBPA, were also assessed after transfection with the LNA-miRs and treatment with resveratrol, gallic acid, and piperine. The expression of miR-17 and miR-181a decreased significantly in LNA-anti-miRs. Although HL-60 cell viability decreased in LNA-anti-miR-222, miR-17, and miR-92b, blockade of miR-181a increased the cell viability. Besides, the cell viability increased merely in the piperine-treated group. Compared to untreated cells, miR-17 and miR-92b expression significantly increased in gallic acid- and resveratrol-treated cells. In HL-60 cells treated with resveratrol, gallic acid, and piperine, the expression of miR-181a was also increased significantly. The expression of BAX was also increased in resveratrol and piperine-treated groups. Compared to untreated cells, the expression of c-Kit increased significantly in the piperine-treated group; however, it decreased in the resveratrol-treated group. LNA-anti-miRs may be a promising agent for the treatment of AML. All three compounds used in this study showed anticancer effects, which can exert the desired outcome in patients with AML.

Piperine induces autophagy of colon cancer cells: Dual modulation of AKT/mTOR signaling pathway and ROS production

BACKGROUND

Colorectal cancer (CRC) is a prevalent malignancy and poses a significant clinical challenge. Piperine, an alkaloid molecule extracted from Piper nigrum and Piper longum, has emerged as a promising anticancer agent. However, the molecular mechanisms of piperine' antitumor effects in CRC need to be further elucidated.

METHODS

Human colorectal cancer cells were treated with piperine in vitro. CCK-8 and clone formation assays were adopted to detect cell viability. The accumulation of autophagosomes was assessed by Western blotting and immunofluorescence. Apoptosis and reactive oxygen species (ROS) levels were analyzed by flow. In vivo, a xenograft tumor mouse model was constructed using CT26 cells.

RESULTS

Piperine inhibited CRC cell viability and suppressed tumor weight and volume in a mouse model. Additionally, piperine treatment induced the accumulation of autophagosomes in CRC cells. This effect was attributed to the inhibition of the AKT/mTOR pathway and the accumulation of ROS. activation of AKT or clearance of ROS attenuated piperine-mediated tumor suppression.

CONCLUSION

This study shows that piperine induces autophagy-dependent cell death in CRC cells by increasing ROS production and inhibiting Akt/mTOR signaling.

The Promise of Piperine in Cancer Chemoprevention

Cancer, characterized by the unregulated growth and dissemination of malignantly transformed cells, presents a significant global health challenge. The multistage process of cancer development involves intricate biochemical and genetic alterations within target cells. Cancer chemoprevention has emerged as a vital strategy to address this complex issue to mitigate cancer's impact on healthcare systems. This approach leverages pharmacologically active agents to block, suppress, prevent, or reverse invasive cancer development. Among these agents, piperine, an active alkaloid with a wide range of therapeutic properties, including antioxidant, anti-inflammatory, and immunomodulatory effects, has garnered attention for its potential in cancer prevention and treatment. This comprehensive review explores piperine's multifaceted role in inhibiting the molecular events and signaling pathways associated with various stages of cancer development, shedding light on its promising prospects as a versatile tool in cancer chemoprevention. Furthermore, the review will also delve into how piperine enhances the effectiveness of conventional treatments such as UV-phototherapy and TRAIL-based therapy, potentially synergizing with existing therapeutic modalities to provide more robust cancer management strategies. Finally, a crucial perspective of the long-term safety and potential side effects of piperine-based therapies and the need for clinical trials is also discussed.

From kitchen to clinic: Pharmacotherapeutic potential of common spices in Indian cooking in age-related neurological disorders

Aging is described as an advanced time-related collection of changes that may negatively affect with the risk of several diseases or death. Aging is a main factor of several age-related neurological disorders, including neurodegenerative diseases (Alzheimer’s disease, Parkinson’s disease, and dementia), stroke, neuroinflammation, neurotoxicity, brain tumors, oxidative stress, and reactive oxygen species (ROS). Currently available medications for age-related neurological disorders may lead to several side effects, such as headache, diarrhea, nausea, gastrointestinal (GI) diseases, dyskinesia, and hallucinosis. These days, studies on plant efficacy in traditional medicine are being conducted because herbal medicine is affordable, safe, and culturally acceptable and easily accessible. The Indian traditional medicine system called Ayurveda uses several herbs and medicinal plants to treat various disorders including neurological disorders. This review aims to summarize the data on the neuroprotective potential of the following common Indian spices widely used in Ayurveda: cumin (Cuminum cyminum (L.), Apiaceae), black cumin (Nigella sativa (L.), Ranunculaceae), black pepper (Piper nigrum (L.), Piperaceae), curry leaf tree (Murraya koenigii (L.), Spreng Rutaceae), fenugreek (Trigonella foenum-graecum (L.), Fabaceae), fennel (Foeniculum vulgare Mill, Apiaceae), cardamom (Elettaria cardamomum (L.) Maton, Zingiberaceae), cloves (Syzygium aromaticum (L.) Merr. & L.M.Perry, Myrtaceae), and coriander (Coriandrum sativum (L.), Apiaceae) in age-related neurological disorders.

Natural Radiosensitizers in Radiotherapy: Cancer Treatment by Combining Ionizing Radiation with Resveratrol

Conventional cancer treatment is mainly based on the surgical removal of the tumor followed by radiotherapy and/or chemotherapy. When surgical removal is not possible, radiotherapy and, less often, chemotherapy is the only way to treat patients. However, despite significant progress in understanding the molecular mechanisms of carcinogenesis and developments in modern radiotherapy techniques, radiotherapy (alone or in combination) does not always guarantee treatment success. One of the main causes is the radioresistance of cancer cells. Increasing the radiosensitivity of cancer cells improves the processes leading to their elimination during radiotherapy and prolonging the survival of cancer patients. In order to enhance the effect of radiotherapy in the treatment of radioresistant neoplasms, radiosensitizers are used. In clinical practice, synthetic radiosensitizers are commonly applied, but scientists have recently focused on using natural products (phytocompounds) as adjuvants in radiotherapy. In this review article, we only discuss naturally occurring radiosensitizers currently in clinical trials (paclitaxel, curcumin, genistein, and papaverine) and those whose radiation sensitizing effects, such as resveratrol, have been repeatedly confirmed by many independent studies.

Natural products as chemo-radiation therapy sensitizers in cancers

Cancer is a devastating disease and is the second leading cause of death worldwide. Surgery, chemotherapy (CT), and/or radiation therapy (RT) are the treatment of choice for most advanced tumors. Unfortunately, treatment failure due to intrinsic and acquired resistance to the current CT and RT is a significant challenge associated with poor patient prognosis. There is an urgent need to develop and identify agents that can sensitize tumor cells to chemo-radiation therapy (CRT) with minimal cytotoxicity to the healthy tissues. While many recent studies have identified the underlying molecular mechanisms and therapeutic targets for CRT failure, using small molecule inhibitors to chemo/radio sensitize tumors is associated with high toxicity and increased morbidity. Natural products have long been used as chemopreventive agents in many cancers. Combining many of these compounds with the standard chemotherapeutic agents or with RT has shown synergistic effects on cancer cell death and overall improvement in patient survival. Based on the available data, there is strong evidence that natural products have a robust therapeutic potential along with CRT and their well-known chemopreventive effects in many solid tumors. This review article reports updated literature on different natural products used as CT or RT sensitizers in many solid tumors. This is the first review discussing CT and RT sensitizers together in cancer.

Pepper Alkaloid Piperine Increases Radiation Sensitivity of Cancer Cells from Glioblastoma and Hypopharynx In Vitro

In our study, our aim was to examine the cytotoxic and radio-sensitizing effect of the alkaloid piperine, a major pungent of black pepper, on two different human epithelial tumor cell lines in vitro. The growth of the human cell lines T98G (glioblastoma) and FaDu (hypopharyngeal carcinoma) was examined under the influence of piperine in different concentrations. In addition, after combined treatment with ionizing radiation, long-term survival was investigated with a colony formation assay. The proliferation was analyzed using the BrdU-assay, while the DNA repair capacity was examined via the γH2AX assay. Piperine reduced the growth of both cell lines in a concentration-dependent manner as well as a time-dependent one. After combined treatment with piperine and ionizing radiation, an inhibition of clonogenic survival could be proven. A reduced proliferation capacity and an additive effect on DNA damage 24 h after irradiation are possible causal mechanisms, which were also demonstrated for both cell lines. Based on the results presented in this study, piperine was shown to have cytotoxic antitumor activity and a radio-sensitizing effect in micromolar concentrations in the human tumor cells that were tested. Based on these results piperine represents a potential therapeutic option in radio-oncological treatment.

Applications of resveratrol in the treatment of gastrointestinal cancer

Natural product compounds have lately attracted interest in the scientific community as a possible treatment for gastrointestinal (GI) cancer, due to their anti-inflammatory and anticancer properties. There are many preclinical, clinical, and epidemiological studies, suggesting that the consumption of polyphenol compounds, which are abundant in vegetables, grains, fruits, and pulses, may help to prevent various illnesses and disorders from developing, including several GI cancers. The development of GI malignancies follows a well-known path, in which normal gastrointestinal cells acquire abnormalities in their genetic composition, causing the cells to continuously proliferate, and metastasize to other sites, especially the brain and liver. Natural compounds with the ability to affect oncogenic pathways might be possible treatments for GI malignancies, and could easily be tested in clinical trials. Resveratrol is a non-flavonoid polyphenol and a natural stilbene, acting as a phytoestrogen with anti-cancer, cardioprotective, anti-oxidant, and anti-inflammatory properties. Resveratrol has been shown to overcome resistance mechanisms in cancer cells, and when combined with conventional anticancer drugs, could sensitize cancer cells to chemotherapy. Several new resveratrol analogs and nanostructured delivery vehicles with improved anti-GI cancer efficacy, absorption, and pharmacokinetic profiles have already been developed. This present review focuses on the in vitro and in vivo effects of resveratrol on GI cancers, as well as the underlying molecular mechanisms of action.

Study of the Radiosensitizing and Radioprotective Efficacy of Bromelain (a Pineapple Extract): In Vitro and In Vivo

This study hypothesizes that, bromelain (BL) acts as radiosensitizer of tumor cells and that it protects normal cells from radiation effects. In vitro and in vivo studies have been carried out to prove that assumption. In vitro MTT cell proliferation assay has shown that the irradiated Ehrlich ascites carcinoma (EAC) cell line could be sensitized by BL pretreatment. In vivo: animals were randomly divided into 5 groups, Group 1: control (PBS i.p for 10 days), Group 2: Ehrlich solid tumor (EST) bearing mice, Group 3: EST + γ-radiation (fractionated dose, 1 Gy × 5), Group 4: EST + BL (6 mg/kg, i.p), daily for 10 days, Group 5: EST + BL for 10 days followed by γ-irradiation (1 Gy × 5). The size and weight of tumors in gamma-irradiated EST bearing mice treated with BL decreased significantly with a significant amelioration in the histopathological examination. Besides, BL mitigated the effect of γ-irradiation on the liver relative gene expression of poly ADP ribose polymerase-1 (PARP1), nuclear factor kappa activated B cells (NF-κB), and peroxisome proliferator-activated receptor α (PPAR-α), and it restored liver function via amelioration of paraoxonase1 (PON1) activity, reactive oxygen species (ROS) content, lipid peroxidation (LPO) and serum aspartate transaminase (AST), alanine transaminase (ALT), and albumin (ALB). It is concluded that BL can be considered as a radio-sensitizer and radio-protector, suggesting a possible role in reducing radiation exposure dose during radiotherapy.

Molecular mechanisms and cardiovascular implications of cancer therapy-induced senescence

Cancer treatment has been associated with accelerated aging that can lead to early-onset health complications typically experienced by older populations. In particular, cancer survivors have an increased risk of developing premature cardiovascular complications. In the last two decades, cellular senescence has been proposed as an important mechanism of premature cardiovascular diseases. Cancer treatments, specifically anthracyclines and radiation, have been shown to induce senescence in different types of cardiovascular cells. Additionally, clinical studies identified increased systemic markers of senescence in cancer survivors. Preclinical research has demonstrated the potential of several approaches to mitigate cancer therapy-induced senescence. However, strategies to prevent and/or treat therapy-induced cardiovascular senescence have not yet been translated to the clinic. In this review, we will discuss how therapy-induced senescence can contribute to cardiovascular complications. Thereafter, we will summarize the current in vitro, in vivo, and clinical evidence regarding cancer therapy-induced cardiovascular senescence. Then, we will discuss interventional strategies that have the potential to protect against therapy-induced cardiovascular senescence. To conclude, we will highlight challenges and future research directions to mitigate therapy-induced cardiovascular senescence in cancer survivors.

Resveratrol sensitizes A549 cells to irradiation damage via suppression of store-operated calcium entry with Orai1 and STIM1 downregulation

Resveratrol is a natural polyphenol with multiple positive biofunctions and was found to have potential as a radiosensitizer with an intricate molecular mechanism. Store-operated calcium entry (SOCE) is a novel intracellular calcium regulatory pattern that is mainly mediated by iron channels, such as by the stromal interaction molecule (STIM) and calcium release-activated calcium channel protein (Orai) families. SOCE was recently reported to be suppressed via the downregulation of STIM or Orai families for the promotion of tumor cell death induced by resveratrol. In the present study, resveratrol combined with irradiation treatment were found to induce more evident cell damage compared with irradiation treatment alone, as shown with Cell Counting Kit-8 assay and mitochondrial membrane potential detection with rhodamine 123. Additionally, resveratrol combined with irradiation treatment decreased the expression of STIM1 and Orai1, while it had no effects on STIM2, Orai2 and Orai3. Moreover, resveratrol combined with irradiation treatment lead to alleviated thapsigargin-induced SOCE. In addition, overexpression of STIM1 and Orai1 reversed resveratrol-induced SOCE inhibition and reduced death in A549 cells under irradiation. In summary, the present results revealed that resveratrol can significantly enhance the effect of irradiation damage on lung adenocarcinoma A549 cells, and this effect may be mediated by suppression of SOCE with reduced expression of both STIM1 and Orai1.

Application of Radiosensitizers in Cancer Radiotherapy

Radiotherapy (RT) is a cancer treatment that uses high doses of radiation to kill cancer cells and shrink tumors. Although great success has been achieved on radiotherapy, there is still an intractable challenge to enhance radiation damage to tumor tissue and reduce side effects to healthy tissue. Radiosensitizers are chemicals or pharmaceutical agents that can enhance the killing effect on tumor cells by accelerating DNA damage and producing free radicals indirectly. In most cases, radiosensitizers have less effect on normal tissues. In recent years, several strategies have been exploited to develop radiosensitizers that are highly effective and have low toxicity. In this review, we first summarized the applications of radiosensitizers including small molecules, macromolecules, and nanomaterials, especially those that have been used in clinical trials. Second, the development states of radiosensitizers and the possible mechanisms to improve radiosensitizers sensibility are reviewed. Third, the challenges and prospects for clinical translation of radiosensitizers in oncotherapy are presented.

Piperine sensitizes radiation-resistant cancer cells towards radiation and promotes intrinsic pathway of apoptosis

Piperine, a bioactive alkaloid, is known to have anticancer activities. Hence, in this study, the effectiveness of piperine pretreatment as a strategy for radio-sensitizing colorectal adenocarcinoma cell line (HT-29) was analyzed. For this, HT-29 cells were pretreated with piperine (12.5 and 25 µg/mL) and exposed to γ-radiation (1.25 Gy) and analyzed for various effector pathways to elucidate the possible mode of action in comparison to individual treatments. The proliferation efficiency of the cells was analyzed by trypan blue dye exclusion assay and MTT assay. The synergistic effects of the combination treatment were analyzed with compuSyn software. Downstream signaling pathways leading to apoptosis were studied using flowcytometry, immunofluorescence, and immunoblot assays. It was observed that combination treatment arrested HT-29 cells at G2/M phase nearly 2.8 folds higher than radiation treatment alone, inducing the radio-resistant cells to undergo apoptosis through mitochondria-dependent pathway. In addition, activation of caspase-3 and cleavage of poly(ADP-ribose) polymerases-1, the key molecular events in apoptotic signaling, were significantly enhanced. Activation of estrogen receptor beta (ERβ), a nuclear hormone transcription factor promoting tumor suppression represents a novel clinical advance towards management and prevention of cancers. Interestingly, the expression of ERβ was increased in the cells treated with piperine. In conclusion, piperine pretreatment enhances radio-sensitization in HT-29 cells by inducing the cells to undergo apoptosis hence, can be used as a classic candidate for colon cancer sensitization towards radiotherapy. PRACTICAL APPLICATION: Piperine induces enhanced radiosensitization of colon cancer cell line (HT-29) by interfering with the cancer cell line proliferation, DNA damage, and apoptosis.

Resveratrol, Curcumin and Piperine Alter Human Glyoxalase 1 in MCF-7 Breast Cancer Cells

Breast cancer is the leading cause of cancer mortality in women worldwide. Conventional cancer treatment is costly and results in many side effects. Dietary bioactive compounds may be a potential source for breast cancer prevention and treatment. In this scenario, the aim of this study was to investigate the effects of the bioactive compounds resveratrol, curcumin and piperine (R-C-P) on MCF-7 breast cancer cells and to associate them to Glyoxalase 1 (GLO1) activity. The findings indicate that R-C-P exhibits cytotoxicity towards MCF-7 cells. R-C-P decreased mitochondrial membrane potential (ΔΨm) by 1.93-, 2.04- and 1.17-fold, respectively. Glutathione and N-acetylcysteine were able to reverse the cytotoxicity of the assessed bioactive compounds in MCF-7 cells. R-C-P reduced GLO1 activity by 1.36-, 1.92- and 1.31-fold, respectively. R-C-P in the presence of antimycin A led to 1.98-, 1.65- and 2.16-fold decreases in D-lactate levels after 2 h of treatment, respectively. Glyoxal and methylglyoxal presented cytotoxic effects on MCF-7 cells, with IC₅₀ values of 2.8 and 2.7 mM and of 1.5 and 1.4 mM after 24 and 48 h of treatment, respectively. In conclusion, this study demonstrated that R-C-P results in cytotoxic effects in MCF-7 cells and that this outcome is associated with decreasing GLO1 activity and mitochondrial dysfunction.

In silico docking of phytocompounds to identify potent inhibitors of signaling pathways involved in prostate cancer

Androgens and androgen receptors (AR) are the master regulators in the development of prostate cancer. Majority of the patients show positive response to surgical or medical castration, while many patients show disease relapse after the treatment. Genomic profiling has proven that the deregulated PI3K, Ras/Raf, MAPK and EGFR signaling pathways confer survival and invasion advantage to the cancer cells. Thus, modulation of these interlinked growth pathways along with androgen ablation may provide attractive therapeutic benefits. The current research is focused to identify the inhibitors of these pathways with bacosides and Piperine. The quantitative estimation of bacosides enriched standard extract of Bacopa monnieri by HPTLC showed 59.38% of Bacoside A and various active compounds with anti-oxidant, anti-cancer, anti-microbial, anti-inflammatory properties were also analyzed by GC-MS analysis. The in-vitro cytotoxic study against PC3 cell lines showed dose-dependent effect of Piperine and the extract. Further, in silico docking has shown bacosides with significant molecular interactions and binding score with growth factor receptors such as EGFR, PI3K, Akt and ERK, whereas Piperine exhibited interactions with AR. Hence, a simultaneous downregulation of interlinked signaling pathways of growth factors and AR with bacosides and Piperine may produce effective cytotoxic potential against the androgen-independent prostate cancer. Further in-vitro and in-vivo experimental investigations are necessary to determine the ultimate therapeutic utility. Communicated by Ramaswamy H. Sarma.

A novel piperine analogue exerts in vivo antitumor effect by inducing oxidative, antiangiogenic and immunomodulatory actions

Structural diversity characterizes natural products as prototypes for design of lead compounds. The aim of this study was to synthetize, and to evaluate the toxicity and antitumor action of a new piperine analogue, the butyl 4-(4-nitrobenzoate)-piperinoate (DE-07). Toxicity was evaluated against zebrafish, and in mice (acute and micronucleus assays). To evaluate the DE-07 antitumor activity Ehrlich ascites carcinoma model was used in mice. Angiogenesis, Reactive Oxygen Species (ROS) production and cytokines levels were investigated. Ninety-six hours exposure to DE-07 did not cause morphological or developmental changes in zebrafish embryos and larvae, with estimated LC₅₀ (lethal concentration 50%) higher than 100 μg/mL. On the acute toxicity assay in mice, LD₅₀ (lethal dose 50%) was estimated at around 1000 mg/kg, intraperitoneally (i.p.). DE-07 (300 mg/kg, i.p.) did not induce increase in the number of micronucleated erythrocytes in mice, suggesting no genotoxicity. On Ehrlich tumor model, DE-07 (12.5, 25 or 50 mg/kg, i.p.) induced a significant decrease on cell viability. In addition, there was an increase on ROS production and a decrease in peritumoral microvessels density. Moreover, DE-07 induced an increase of cytokines levels involved in oxidative stress and antiangiogenic effect (IL-1β, TNF-α and IL-4). No significant clinical toxicological effects were recorded in Ehrlich tumor transplanted animals. These data provide evidence that DE-07 presents low toxicity, and antitumor effect via oxidative and antiangiogenic actions by inducing modulation of inflammatory response in the tumor microenvironment.

Metabolomic Analysis of Radiation-Induced Lung Injury in Rats: The Potential Radioprotective Role of Taurine

Radiation-induced lung injury is a major dose-limiting toxicity that occurs due to thoracic radiotherapy. Metabolomics is a powerful quantitative measurement of low-molecular-weight metabolites in response to environmental disturbances. However, the metabolomic profiles of radiation-induced lung injury have not been reported yet. In this study, male Sprague-Dawley rats were subjected to a single dose of 10 or 20 Gy irradiation to the right lung. One week after radiation, the obvious morphological alteration of lung tissues after radiation was observed by hematoxylin and eosin staining through a transmission electron microscope. We then analyzed the metabolites and related pathways of radiation-induced lung injury by gas chromatography-mass spectrometry, and a total of 453 metabolites were identified. Compared to the nonirradiated left lung, 19 metabolites (8 upregulated and 11 downregulated) showed a significant difference in 10 Gy irradiated lung tissues, including mucic acid, methyl-β-d-galactopyranoside, quinoline-4-carboxylic acid, and pyridoxine. There were 31 differential metabolites (16 upregulated and 15 downregulated) between 20 Gy irradiated and nonirradiated lung tissues, including taurine, piperine, 1,2,4-benzenetriol, and lactamide. The Kyoto Encyclopedia of Genes and Genomes-based pathway analysis enriched 32 metabolic pathways between the irradiated and nonirradiated lung tissues, including pyrimidine metabolism, ATP-binding cassette transporters, aminoacyl-tRNA biosynthesis, and β-alanine metabolism. Among the dysregulated metabolites, we found that taurine promoted clonogenic survival and reduced radiation-induced necrosis in human embryonic lung fibroblast (HELF) cells. This study provides evidence indicating that radiation induces metabolic alterations of the lung. These findings significantly advance our understanding of the pathophysiology of radiation-induced lung injury from the perspective of metabolism.

Leveraging the Cardio-Protective and Anticancer Properties of Resveratrol in Cardio-Oncology

Cardio-oncology is a clinical/scientific discipline which aims to prevent and/or treat cardiovascular diseases in cancer patients. Although a large number of cancer treatments are known to cause cardiovascular toxicity, they are still widely used because they are highly effective. Unfortunately, therapeutic interventions to prevent and/or treat cancer treatment-induced cardiovascular toxicity have not been established yet. A major challenge for such interventions is to protect the cardiovascular system without compromising the therapeutic benefit of anticancer medications. Intriguingly, the polyphenolic natural compound resveratrol and its analogs have been shown in preclinical studies to protect against cancer treatment-induced cardiovascular toxicity. They have also been shown to possess significant anticancer properties on their own, and to enhance the anticancer effect of other cancer treatments. Thus, they hold significant promise to protect the cardiovascular system and fight the cancer at the same time. In this review, we will discuss the current knowledge regarding the cardio-protective and the anticancer properties of resveratrol and its analogs. Thereafter, we will discuss the challenges that face the clinical application of these agents. To conclude, we will highlight important gaps of knowledge and future research directions to accelerate the translation of these exciting preclinical findings to cancer patient care.

Combination treatment of resveratrol and capsaicin radiosensitizes pancreatic tumor cells by unbalancing DNA repair response to radiotherapy towards cell death

Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest cancers because it is highly resistant to every available therapeutic strategy, in particular conventional chemotherapy or radiotherapy (RT). Sensitizing tumor cells to existing treatments remains a good option to obtain fast and applicable results. Considering that ionizing radiations induce radiolysis-derived reactive oxygen species (ROS), we hypothesized that ROS-inducing bioactive food components (BFCs) could exacerbate ROS-related cell damages, including DNA double stranded breaks (DSBs), leaving the cellular ROS scavenging systems overwhelmed, and precipitating tumor cell death. Combination of resveratrol and capsaicin radiosensitized radiosensitive tumor cells, but RT did not increase BFC combination toxicity in radioresistant tumor cells. BFC addition to RT increased ROS production and led to significant tumor volume reduction in xenografted mouse preclinical model. Strikingly, BFCs inhibited RT-induced DNA damage molecular response by strongly limiting the first steps of DSB repair, and by keeping cells in cell cycle, provoking exacerbated intrinsic apoptosis. This study positions BFCs as potent radiosensitizers when combined, and identifies an actionable molecular pathway by resveratrol and capsaicin combination.

Combined effects of resveratrol and radiation in GH3 and TtT/GF pituitary adenoma cells

OBJECTIVE

Resveratrol and radiation decrease viability in various tumor cells. This study aims to investigate combined effects of resveratrol and radiation on viability, induction of apoptosis and necrosis, and expression of apoptosis modulators in rodent GH3 and TtT/GF pituitary adenoma cells in vitro.

METHODS

Cells were incubated with 10-100 µM resveratrol. Medium and medium with ethanol served as controls. After 2 h, cells were irradiated with 0-5 Gray (Gy) and further incubated for 48-72 h. Cell viability was quantified using a hemocytometer. Cell death was assessed with an enzyme-linked immunosorbent assay (ELISA) that detects free nucleosomes in cell lysates and free nucleosomes released to the culture medium. Expression of B-cell lymphoma-2 protein (BCL-2) and BCL-2 associated Xprotein (BAX) was measured using quantitative real time-polymerase chain reaction (qRT-PCR) to analyze changes in BAX/BCL-2 ratio.

RESULTS

Resveratrol and irradiation with 4 Gy alone and in combination significantly decreased cell viability (p = 0.017 and less). In the ELISA, 10 μM resveratrol significantly induced apoptosis in TtT/GF cells at 0 Gy (p < 0.001), but not at 3 or 5 Gy. In the ELISA, 10 μM resveratrol significantly induced necrosis in GH3 cells at 0, 3 and 5 Gy (p < 0.001). While qRT-PCR did not demonstrate a significant effect of 10 µM resveratrol or radiation on expression of BAX or BCL-2, a significant increase in the BAX/BCL-2 ratio was found after irradiation with 5 Gy in GH3 cells (p = 0.0027).

CONCLUSION

While moderate irradiation solely led to inhibited proliferation, resveratrol induced cell death in rodent pituitary adenoma cells.

Cancer Chemoprevention and Piperine: Molecular Mechanisms and Therapeutic Opportunities

Cancer is a genetic disease characterized by unregulated growth and dissemination of malignantly transformed neoplastic cells. The process of cancer development goes through several stages of biochemical and genetic alterations in a target cell. Several dietary alkaloids have been found to inhibit the molecular events and signaling pathways associated with various stages of cancer development and therefore are useful in cancer chemoprevention. Cancer chemoprevention has long been recognized as an important prophylactic strategy to reduce the burden of cancer on health care system. Cancer chemoprevention assumes the use of one or more pharmacologically active agents to block, suppress, prevent, or reverse the development of invasive cancer. Piperine is an active alkaloid with an excellent spectrum of therapeutic activities such as anti-oxidant, anti-inflammatory, immunomodulatory, anti-asthmatic, anti-convulsant, anti-mutagenic, antimycobacterial, anti-amoebic, and anti-cancer activities. In this article, we made an attempt to sum up the current knowledge on piperine that supports the chemopreventive potential of this dietary phytochemical. Many mechanisms have been purported to understand the chemopreventive action of piperine. Piperine has been reported to inhibit the proliferation and survival of many types of cancer cells through its influence on activation of apoptotic signaling and inhibition of cell cycle progression. Piperine is known to affect cancer cells in variety of other ways such as influencing the redox homeostasis, inhibiting cancer stem cell (CSC) self-renewal and modulation of ER stress and autophagy. Piperine can modify activity of many enzymes and transcription factors to inhibit invasion, metastasis, and angiogenesis. Piperine is a potent inhibitor of p-glycoprotein (P-gp) and has a significant effect on the drug metabolizing enzyme (DME) system. Because of its inhibitory influence on P-gp activity, piperine can reverse multidrug resistance (MDR) in cancer cells and acts as bioavailability enhancer for many chemotherapeutic agents. In this article, we emphasize the potential of piperine as a promising cancer chemopreventive agent and the knowledge we collected in this review can be applied in the strategic design of future researches particularly human intervention trials with piperine.

Potential Contributions of Antioxidants to Cancer Therapy: Immunomodulation and Radiosensitization

Antioxidants play important roles in the maintenance of cellular integrity and thus are critical in maintaining the homeostasis of the host immune system. A balance between the levels of pro-oxidants and antioxidants defines the cellular fate of genomic integrity via maintaining the redox status of the cells. An aberration in this balance modulates host immunity that affects normal cellular signaling pathways resulting in uncontrolled proliferation of cells leading to neocarcinogenesis. For decades, there have been scientific debates on the use of antioxidants for the treatment of human cancers. This review is focused on current updates on the implications of antioxidant use as adjuncts in cancer therapy with an emphasis on immunomodulation and radiosensitization.

Phytomedicine-Modulating oxidative stress and the tumor microenvironment for cancer therapy

In spite of the current advances and achievements in systems biology and translational medicinal research, the current strategies for cancer therapy, such as radiotherapy, targeted therapy, immunotherapy and chemotherapy remain palliative or unsatisfactory due to tumor metastasis or recurrence after surgery/therapy, drug resistance, adverse side effects, and so on. Oxidative stress (OS) plays a critical role in chronic/acute inflammation, carcinogenesis, tumor progression, and tumor invasion/metastasis which is also attributed to the dynamic and complex properties and activities in the tumor microenvironment (TME). Re-educating or reprogramming tumor-associated stromal or immune cells in the TME provides an approach for restoring immune surveillance impaired by disease in cancer patients to increase overall survival and reduce drug resistance. Herbal medicines or plant-derived natural products have historically been a major source of anti-cancer drugs. Delving into the lore of herbal medicine may uncover new leads for anti-cancer drugs. Phytomedicines have been widely documented to directly or indirectly target multiple signaling pathways and networks in cancer cells. A combination of anti-cancer drugs and polypharmacological plant-derived extracts or compounds may offer a significant advantage in sensitizing the efficacy of monotherapy and overcoming drug-induced resistance in cancer patients. This review introduces several phytochemicals and phytoextracts derived from medicinal plants or dietary vegetables that have been studied for their efficacy in preclinical cancer models. We address the underlying modes of action of induction of OS and deregulation of TME-associated stromal cells, mediators and signaling pathways, and reference the related clinical investigations that look at the single or combination use of phytochemicals and phytoextracts to sensitize anti-cancer drug effects and/or overcome drug resistance.

Synergistic effect of piperine and paclitaxel on cell fate via cyt-c, Bax/Bcl-2-caspase-3 pathway in ovarian adenocarcinomas SKOV-3 cells

BACKGROUND AND AIMS

Ovarian cancer is fourth most common and lethal among all gynecologic malignancies. The chemotherapy usually requires in all stages of ovarian cancer but drugs have several side effects. We hypothesized that use of combination therapy of paclitaxel (PTX) and phytochemical piperine (PIP) may reduce the PTX dose as well as toxicity. The human ovarian adenocarcinomas SKOV3 cell treated with PTX-5nM and PIP-10µm after determination of IC₅₀ by MTT assay. Reactive oxygen species generation, mitochondrial membrane potential (MMP), DNA damage, cell death pathway markers as release of cyt-c, Bax/Bcl2-caspase-3 and cell cycle arrest were analyzed. The dose dependent treatment of SKOV-3 cells showed IC₅₀ and synergism at combination of 5nM-PTX and 10µm-PIP in cell viability assay. PTX and PIP increases the accumulation of reactive oxygen species which subsequently leading to increase in JC-1 and fragmented nuclei in mitotracker/DAPI staining. Comet assay showed 4.4-fold increase of tail formation in combined treated cells as compared to control. PTX-PIP arrests the cell cycle in sub-G1 phase. Immunocytochemistry of Bax showed increase in red fluorescence intensity whereas decrease in green fluorescence i.e Bax/Bcl-2 ratio increased. Moreover morphological EB/AO and Hoechst staining confirmed the enhanced apoptosis in combined treatment. Significant upregulation of apoptotic genes, cyt-c (3.4 fold) Bax (2.8 fold), caspase-3 (3.6 fold) whereas no change occurred in Bcl2 mRNA expression and protein expressions. The combination of PTX with PIP produces synergistic effects in SKOV-3 cells via the modulation of pro and anti-apoptotic gene and may compensate the toxicity and side effects of PTX.

Modulation of signal transduction pathways by natural compounds in cancer

Cancer is generally regarded as the result of abnormal growth of cells. According to World Health Organization, cancer is the leading cause of mortality worldwide. Mother nature provides a large source of bioactive compounds with excellent therapeutic efficacy. Numerous phytochemicals from nature have been investigated for anticancer properties. In this review article, we discuss several natural compounds, which have shown anti-cancer activity. Natural compounds induce cell cycle arrest, activate intrinsic and extrinsic apoptosis pathways, generate Reactive Oxygen Species (ROS), and down-regulate activated signaling pathways, resulting in inhibition of cell proliferation, progression and metastasis of cancer. Several preclinical studies have suggested that natural compounds can also increase the sensitivity of resistant cancers to available chemotherapy agents. Furthermore, combining FDA approved anti-cancer drugs with natural compounds results in improved efficacy. On the basis of these exciting outcomes of natural compounds against several cancer types, several agents have already advanced to clinical trials. In conclusion, preclinical results and clinical outcomes against cancer suggest promising anticancer efficacy of agents from natural sources.

South Asian Medicinal Compounds as Modulators of Resistance to Chemotherapy and Radiotherapy

Cancer is a hyperproliferative disorder that involves transformation, dysregulation of apoptosis, proliferation, invasion, angiogenesis and metastasis. During the last 30 years, extensive research has revealed much about the biology of cancer. Chemotherapy and radiotherapy are the mainstays of cancer treatment, particularly for patients who do not respond to surgical resection. However, cancer treatment with drugs or radiation is seriously limited by chemoresistance and radioresistance. Various approaches and strategies are employed to overcome resistance to chemotherapy and radiation treatment. Many plant-derived phytochemicals have been investigated for their chemo- and radio-sensitizing properties. The peoples of South Asian countries such as India, Pakistan, Sri Lanka, Nepal, Bangladesh and Bhutan have a large number of medicinal plants from which they produce various pharmacologically potent secondary metabolites. The medicinal properties of these compounds have been extensively investigated and many of them have been found to sensitize cancer cells to chemo- and radio-therapy. This review focuses on the role of South Asian medicinal compounds in chemo- and radio-sensitizing properties in drug- and radio-resistant cancer cells. Also discussed is the role of South Asian medicinal plants in protecting normal cells from radiation, which may be useful during radiotherapy of tumors to spare surrounding normal cells.

Targeted intracellular delivery of resveratrol to glioblastoma cells using apolipoprotein E-containing reconstituted HDL as a nanovehicle

The objective of this study is to transport and deliver resveratrol to intracellular sites using apolipoprotein E3 (apoE3). Reconstituted high-density lipoprotein (rHDL) bearing resveratrol (rHDL/res) was prepared using phospholipids and the low-density lipoprotein receptor (LDLr)-binding domain of apoE3. Biophysical characterization revealed that resveratrol was partitioned into the phospholipid bilayer of discoidal rHDL/res particles (~19 nm diameter). Co-immunoprecipitation studies indicated that the LDLr-binding ability of apoE3 was retained. Cellular uptake of resveratrol to intracellular sites was evaluated in glioblastoma A-172 cells by direct fluorescence using chemically synthesized NBD-labeled resveratrol (res/NBD) embedded in rHDL/res. Competition and inhibition studies indicate that the uptake is by receptor mediated endocytosis via the LDLr, with co-localization of apoE3 and res/NBD in late endosomes/lysosomes. We propose that rHDL provides an ideal hydrophobic milieu to sequester resveratrol and that rHDL containing apoE3 serves as an effective “nanovehicle” to transport and deliver resveratrol to targeted intracellular sites.

Enhancing the delivery of resveratrol in humans: if low bioavailability is the problem, what is the solution?

Resveratrol has emerged as a leading candidate for improving healthspan through potentially slowing the aging process and preventing chronic diseases. The poor bioavailability of resveratrol in humans has been a major concern for translating basic science findings into clinical utility. Although a number of positive findings have emerged from human clinical trials, there remain many conflicting results, which may partially be attributed to the dosing protocols used. A number of theoretical solutions have been developed to improve the bioavailability of resveratrol, including consumption with various foods, micronized powders, combining it with additional phytochemicals, controlled release devices, and nanotechnological formulations. While laboratory models indicate these approaches all have potential to improve bioavailability of resveratrol and optimize its clinical utility, there is surprisingly very little data regarding the bioavailability of resveratrol in humans. If bioavailability is indeed a limitation in the clinical utility of resveratrol, there is a need to further explore methods to optimize bioavailability in humans. This review summarizes the current bioavailability data, focusing on data from humans, and provides suggested directions for future research in this realm.

Enhancement of radiosensitization by metal-based nanoparticles in cancer radiation therapy

Radiation therapy performs an important function in cancer treatment. However, resistance of tumor cells to radiation therapy still remains a serious concern, so the study of radiosensitizers has emerged as a persistent hotspot in radiation oncology. Along with the rapid advancement of nanotechnology in recent years, the potential value of nanoparticles as novel radiosensitizers has been discovered. This review summarizes the latest experimental findings both in vitro and in vivo and attempts to highlight the underlying mechanisms of response in nanoparticle radiosensitization.

Involvement of autophagy in cordycepin-induced apoptosis in human prostate carcinoma LNCaP cells

Cordycepin, an active ingredient of the insect fungus Cordyceps spp., shows strong antioxidant and anticancer activities. Several molecular mechanisms have been attributed to its inhibitory effects on a wide range of tumor cells; however, the mechanism causing cancer cell death is still obscure. For the current study, we further investigated the mechanism responsible for targeting cordycepin-induced cell death and its association with autophagy in human prostate carcinoma LNCaP cells. Our results show that cordycepin resulted in significant reduction in LNCaP cell survival by inducing apoptotic cell death. Cordycepin treatment caused a dose-dependent increase of pro-apoptotic Bax and decrease of anti-apoptotic Bcl-2, triggering collapse of the mitochondrial membrane potential and activation of caspase-9 and -3. Cordycepin-induced cell death was also associated with induction of Fas and death receptor 5, activation of caspase-8, and truncation of Bid (tBid), suggesting that tBid might serve to connect activation of both the mitochondrial-mediated intrinsic and death receptor-mediated extrinsic apoptotic pathways. The general caspase inhibitor, z-VAD-fmk, completely abolished cordycepin-induced cell death, demonstrating that cordycepin-induced apoptosis was dependent on the activation of caspases. Cordycepin also stimulated autophagy, which was evidenced by an increase in microtubule-associated protein light chain-3 (LC3) puncta, accumulation of LC3-II, and elevation of autophagic flux; however, blockage of autophagic flux by the autophagic inhibitor bafilomycin A1 promoted cell-switching to apoptotic cell death. These findings suggest that cordycepin-induced autophagy functions as a survival mechanism and that autophagy is a potential strategy for treating prostate cancer that is resistant to pro-apoptotic therapeutics.

Redox proteins and radiotherapy

Although conventional radiotherapy can directly damage DNA and other organic molecules within cells, most of the damage and the cytotoxicity of such ionising radiation, comes from the production of ions and free radicals produced via interactions with water. This 'indirect effect', a form of oxidative stress, can be modulated by a variety of systems within cells that are in place to, in normal situations, maintain homeostasis and redox balance. If cancer cells express high levels of antioxidant redox proteins, they may be more resistant to radiation and so targeting such systems may be a profitable strategy to increase therapeutic efficacy of conventional radiotherapy. An overview, with exemplars, of the main systems regulating redox homeostasis is supplied and discussed in relation to their use as prognostic and predictive biomarkers, and how targeting such proteins and systems may increase radiosensitivity and, potentially, improve the radiotherapeutic response.

Piperine potentiates the antidepressant-like effect of trans-resveratrol: involvement of monoaminergic system

Major depression is characterized by dysfunction of neuroendocrine and immune networks. Trans-resveratrol, a phenolic compound presented in polygonum cuspidatum, was demonstrated previously to exert antidepressant-like effects through regulating monoaminergic system, oxidative/antioxidant defense and inflammatory response. The present study investigated the synergistic antidepressant-like effect of trans-resveratrol and piperine, a bioavailability enhancer, in mice and explored the possible mechanism. Trans-resveratrol was shown to reduce the immobility time both in the tail suspension and forced swimming tests (TST and FST). But the maximal inhibition was nearly 60% even if the doses were increased by 160 mg/kg; while piperine produced weak antidepressant-like effects in these two models. The interaction between trans-resveratrol and piperine was shown a clear-cut synergistic effect as evidenced by an isobolographic analysis. The further study suggested that the anti-immobility response from the subthreshold dose of piperine (2.5 mg/kg) and low doses of trans-resveratrol (10 and 20 mg/kg) was abolished by pretreatment with para-chlorophenylalanine (PCPA, 300 mg/kg, i.p.) in TST and FST, indicating the involvement of serotonergic system. Moreover, treatment with the subthreshold dose of piperine and low doses of trans-resveratrol attenuated reserpine-induced hypothermia and ptosis arguing for the relevance of noradrenaline. Additional evidence from neurochemical (monoamines in the frontal cortex, hippocampus, and hypothalamus) and biochemical (monoamine oxidase, MAO activity) assays corroborated the synergistically elevated monoaminergic system after co-treatment with trans-resveratrol and piperine. The present results indicate the effect of trans-resveratrol combined with piperine on depressive-like behaviors may be partly due to the potentiated activation of monoaminergic system in the brain. Further studies are necessary to elucidate the involvement of the oxidative/nitrosative stress, inflammatory and neuroprotective pathway in the antidepressant-like effect of this combination. The synergistic effect obtained from the combination may provide innovative clues for designing novel antidepressants with high efficacy and low side effects.

Resveratrol-based combinatorial strategies for cancer management

In recent years combination chemoprevention has been increasingly appreciated and investigated as a viable and effective strategy for cancer management. A plethora of evidence suggests that a combination of agents may afford synergistic (or additive) advantage for cancer management by multiple means, such as by (1) enhancing the bio-availability of chemopreventive agents, (2) modifying different molecular targets, and (3) lowering the effective dose of agent/drug to be used for cancer management. Resveratrol has been shown to afford chemopreventive and therapeutic effects against certain cancers. Recent studies are suggesting that resveratrol may be very useful when given in combination with other agents. The two major advantages of using resveratrol in combination with other agents are synergistically or additively enhancing the efficacy against cancer and limiting the toxicity and side effects of existing therapies. However, concerted and multidisciplinary efforts are needed to identify the most optimal combinatorial strategies.

Curcumin induces radiosensitivity of in vitro and in vivo cancer models by modulating pre-mRNA processing factor 4 (Prp4)

Radiation therapy plays a central role in adjuvant strategies for the treatment of both pre- and post-operative human cancers. However, radiation therapy has low efficacy against cancer cells displaying radio-resistant phenotypes. Ionizing radiation has been shown to enhance ROS generation, which mediates apoptotic cell death. Further, concomitant use of sensitizers with radiation improves the efficiency of radiotherapy against a variety of human cancers. Here, the radio-sensitizing effect of curcumin (a derivative of turmeric) was investigated against growth of HCT-15 cells and tumor induction in C57BL/6J mice. Ionizing radiation induced apoptosis through ROS generation and down-regulation of Prp4K, which was further potentiated by curcumin treatment. Flow cytometry revealed a dose-dependent response for radiation-induced cell death, which was remarkably reversed by transfection of cells with Prp4K clone. Over-expression of Prp4K resulted in a significant decrease in ROS production possibly through activation of an anti-oxidant enzyme system. To elucidate an integrated mechanism, Prp4K knockdown by siRNA ultimately restored radiation-induced ROS generation. Furthermore, B16F10 xenografts in C57BL/6J mice were established in order to investigate the radio-sensitizing effect of curcumin in vivo. Curcumin significantly enhanced the efficacy of radiation therapy and reduced tumor growth as compared to control or radiation alone. Collectively, these results suggest a novel mechanism for curcumin-mediated radio-sensitization of cancer based on ROS generation and down-regulation of Prp4K.

Resveratrol decreases B-cell lymphoma-2 expression and viability in GH3 pituitary adenoma cells of the rat

Objective

Resveratrol is a phytoestrogen with various antiproliferative and proapoptotic effects. This in vitro study aimed to analyze the effect of resveratrol on the viability and expression of modulators of apoptosis in GH3 pituitary adenoma cells of the rat.

Methods

GH3 cells were incubated with resveratrol concentrations from 20 to 100 μM for 48–72 hours. Cell viability was quantified using a hemocytometer. We assessed the ability of resveratrol to kill GH3 cells by an enzyme-linked immunosorbent assay (ELISA) of nucleosome liberation and by DNA degradation (unidimensional gel electrophoresis). Relative messenger RNA (mRNA) expression of survivin, B-cell lymphoma-2 protein (BCL-2) and BCL-2-associated X protein (BAX) normalized to β2 microglobulin was measured using quantitative real-time polymerase chain reaction (qRT-PCR).

Results

GH3 cell survival significantly decreased with increasing concentrations of resveratrol. In GH3 cells treated with 100 μM resveratrol, ELISA demonstrated a significant rise of nucleosome liberation, which typically occurs during apoptosis. In parallel, gel electrophoresis showed degradation of DNA into random fragments, pointing to a necrotic mode of cell death in most GH3 cells. In GH3 cells treated with 100 μM resveratrol, qRT-PCR detected a significant decrease of BCL-2 mRNA expression and a decrease of survivin mRNA expression, whereas a change of BAX mRNA expression could not be found. The BAX/BCL-2 ratio was significantly increased in GH3 cells after resveratrol treatment.

Conclusions

Resveratrol reduces GH3 cell viability in a dose-dependent manner by inducing nonapoptotic cell death and apoptosis. Apoptosis in GH3 cells is probably mediated by resveratrol-dependent downregulation of apoptosis inhibitors, namely BCL-2 and possibly survivin. Further investigation of the potential effects of resveratrol on pituitary adenoma cells is warranted.

Cordycepin increases sensitivity of Hep3B human hepatocellular carcinoma cells to TRAIL-mediated apoptosis by inactivating the JNK signaling pathway

Resistance to tumor necrosis factor-related apoptosis‑inducing ligand (TRAIL)-induced apoptosis has been reported in various cancer cells. Cordycepin, a specific polyadenylation inhibitor, is the main functional component in Cordyceps militaris, which possesses many pharmacological activities including antitumor and anti-inflammation. In the present study, we demonstrated that treatment of cordycepin sensitized TRAIL-resistant Hep3B human hepatocellular carcinoma cells to TRAIL-mediated apoptosis as evidenced by formation of apoptotic bodies, chromatin condensation and accumulation of cells in the sub-G1 phase. The induction of apoptosis following co-treatment with cordycepin and TRAIL in Hep3B cells appeared to be correlated with modulation of Bcl-2 family protein expression and activation of the caspase cascade, which resulted in the cleavage of poly(ADP-ribose) polymerase and β-catenin. In addition, cordycepin treatment also inhibited activation of c-Jun N-terminal kinase (JNK). Pretreatment with SP600125, a JNK inhibitor, resulted in a significantly increased sub-G1 population and caspase activity in cordycepin plus TRAIL-mediated apoptosis. Taken together, these results indicate that JNK acts as a key regulator of apoptosis in response to combined treatment with cordycepin and TRAIL in human hepatocellular carcinoma Hep3B cells.

The use of antioxidants in radiotherapy-induced skin toxicity

Radiation-induced skin damage is one of the most common complications of radiotherapy. In order to combat these side effects, patients often turn to alternative therapies, which often include antioxidants. Antioxidants such as those in the polyphenol chemical class, xanthine derivatives, tocepherol, sucralfate, and ascorbate have been studied for their use in either preventing or treating radiotherapy-induced skin damage. Apart from their known role as free radical scavengers, some of these antioxidants appear to alter cytokine release affecting cutaneous and systemic changes. We review the role of antioxidants in treating and preventing radiation-induced skin damage as well as the possible complications of using such therapy.

Apoptosis induction of human bladder cancer cells by sanguinarine through reactive oxygen species-mediated up-regulation of early growth response gene-1

Although the effects of sanguinarine, a benzophenanthridine alkaloid, on the inhibition of some kinds of cancer cell growth have been established, the underlying mechanisms are not completely understood. This study investigated possible mechanisms by which sanguinarine exerts its anticancer action in cultured human bladder cancer cell lines (T24, EJ, and 5637). Sanguinarine treatment resulted in concentration-response growth inhibition of the bladder cancer cells by inducing apoptosis. Sanguinarine-induced apoptosis was correlated with the up-regulation of Bax, the down-regulation of Bid and XIAP, the activation of caspases (-3, -8, and -9), and the generation of increased reactive oxygen species (ROS). The ROS scavenger N-acetyl cysteine (NAC) completely reversed the sanguinarine-triggered apoptotic events. In addition, sanguinarine effectively increased the activation of the c-Jun N-terminal kinase (JNK) and the expression of the early growth response gene-1 (Egr-1), which was recovered by pretreatment with NAC. Furthermore, knockdown of Egr-1 expression by small interfering RNA attenuated sanguinarine-induced apoptosis, but not the JNK inhibitor, indicating that the interception of ROS generation blocked the sanguinarine-induced apoptotic effects via deregulation of the expression of Egr-1 proteins. Taken together, the data provide evidence that sanguinarine is a potent anticancer agent, which inhibits the growth of bladder cancer cells and induces their apoptosis through the generation of free radicals.

Sanguinarine induces apoptosis in human colorectal cancer HCT-116 cells through ROS-mediated Egr-1 activation and mitochondrial dysfunction

We examined the effects of sanguinarine, a benzophenanthridine alkaloid, on reactive oxygen species (ROS) production and the association of these effects with apoptotic cell death in a human colorectal cancer HCT-116 cell line. Sanguinarine generated ROS, which was followed by a decrease in the mitochondrial membrane potential (MMP), the activation of caspase-9 and -3, and the down-regulation of anti-apoptotic proteins, such as Bcl2, XIAP and cIAP-1. Sanguinarine also promoted the activation of caspase-8 and truncation of Bid (tBid). However, the quenching of ROS generation by N-acetyl-l-cysteine, a scavenger of ROS, reversed the sanguinarine-induced apoptosis effects via inhibition of the MMP collapse, tBid expression, and activation of caspases. Sanguinarine also markedly induced the expression of the early growth response gene-1 (Egr-1) during the early period, after which expression level was decreased. In addition, HCT-116 cells transfected with Egr-1 siRNA displayed significant blockage of sanguinarine-induced apoptotic activity in a ROS-dependent manner. These observations clearly indicate that ROS, which are key mediators of Egr-1 activation and MMP collapse, are involved in the early molecular events in the sanguinarine-induced apoptotic pathway acting in HCT-116 cells.

Apoptosis induction of human prostate carcinoma DU145 cells by diallyl disulfide via modulation of JNK and PI3K/AKT signaling pathways

Diallyl disulfide (DADS), a sulfur compound derived from garlic, has various biological properties, such as anticancer, antiangiogenic and anti-inflammatory effects. However, the mechanisms of action underlying the compound’s anticancer activity have not been fully elucidated. In this study, the apoptotic effects of DADS were investigated in DU145 human prostate carcinoma cells. Our results showed that DADS markedly inhibited the growth of the DU145 cells by induction of apoptosis. Apoptosis was accompanied by modulation of Bcl-2 and inhibitor of apoptosis protein (IAP) family proteins, depolarization of the mitochondrial membrane potential (MMP, ΔΨm) and proteolytic activation of caspases. We also found that the expression of death-receptor 4 (DR4) and Fas ligand (FasL) proteins was increased and that the level of intact Bid proteins was down-regulated by DADS. Moreover, treatment with DADS induced phosphorylation of mitogen-activated protein kinases (MAPKs), including extracellular-signal regulating kinase (ERK), p38 MAPK and c-Jun N-terminal kinase (JNK). A specific JNK inhibitor, SP600125, significantly blocked DADS-induced-apoptosis, whereas inhibitors of the ERK (PD98059) and p38 MAPK (SB203580) had no effect. The induction of apoptosis was also accompanied by inactivation of phosphatidylinositol 3-kinase (PI3K)/Akt and the PI3K inhibitor LY29004 significantly increased DADS-induced cell death. These findings provide evidence demonstrating that the proapoptotic effect of DADS is mediated through the activation of JNK and the inhibition of the PI3K/Akt signaling pathway in DU145 cells.