Curcuminoids Induce Reactive Oxygen Species and Autophagy to Enhance Apoptosis in Human Oral Cancer Cells

Luteolin Protects against Vascular Calcification by Modulating SIRT1/CXCR4 Signaling Pathway and Promoting Autophagy

Vascular calcification (VC) is a common pathological manifestation of atherosclerosis, hypertension, diabetes vascular disease, vascular injury, chronic kidney disease and aging, which is mainly manifested as increased stiffness of the vascular wall. Oxidative stress and autophagy dysfunction are key factors in the pathogenesis of vascular calcification, but the specific mechanisms and the therapeutic strategy of vascular calcification have not been clarified. In the present study, Sirtuin 1 (SIRT1) was screened as the therapeutic targets for vascular calcification by the bioinformatics. SIRT1 is a nicotinamide adenine dinucleotide, which plays an important role in inhibiting oxidative stress and promoting autophagy. Luteolin (LUT), a kind of natural tetrahydroxyl flavonoid, exists in many plants and has many pharmacological effects such as anti-oxidation and anti-apoptosis. We have reported that luteolin has certain anti-osteoporosis effects in the previous study, and it is accepted that the development of vascular calcification is similar to bone formation, indicating that luteolin may also resist vascular calcification. And luteolin is known to activate SIRT1 to some extent. Moreover, the molecular docking analysis predicted that SIRT1 could bind directly to luteolin. Therefore, the purpose of this study was to investigate the potential role of luteolin in inhibiting oxidative stress and promoting autophagy during vascular calcification via modulating SIRT1 expression. The results showed that luteolin significantly improved vascular calcification induced by a high-fat diet (HFD) and vitamin D3 in rats in vivo. In addition, luteolin significantly repressed the formation of mineralized nodules and ALP activity in H2O2-treated A7r5 cells. Luteolin reduced the level of MDA, LDH and ROS generation, inhibited the protein expression of cleaved caspase-3, cleaved caspase-9, β-catenin and BMP-2 in the aortic tissue of the rat and rat smooth muscle cells (A7r5) treated with hydrogen peroxide. At the same time, luteolin could promote the expression of autophagy related proteins. Moreover, luteolin also produced effects to increase the protein expression levels of SIRT1 more than 2 times both in vivo and in vitro. In terms of mechanism, luteolin attenuated vascular calcification by inhibiting oxidative stress and improving autophagy level, via modulating SIRT1 / CXCR4 signaling pathway. In conclusion, this experiment for the first time revealed that LUT protected against VC via modulating SIRT1 / CXCR4 signaling pathway to promote autophagy and inhibit vascular calcification and may be developed as a new therapeutic agent for vascular calcification and atherosclerosis.

Advances in natural products modulating autophagy influenced by cellular stress conditions and their anticancer roles in the treatment of ovarian cancer

Autophagy is a conservative catabolic process that typically serves a cell-protective function. Under stress conditions, when the cellular environment becomes unstable, autophagy is activated as an adaptive response for self-protection. Autophagy delivers damaged cellular components to lysosomes for degradation and recycling, thereby providing essential nutrients for cell survival. However, this function of promoting cell survival under stress conditions often leads to malignant progression and chemotherapy resistance in cancer. Consequently, autophagy is considered a potential target for cancer therapy. Herein, we aim to review how natural products act as key modulators of autophagy by regulating cellular stress conditions. We revisit various stressors, including starvation, hypoxia, endoplasmic reticulum stress, and oxidative stress, and their regulatory relationship with autophagy, focusing on recent advances in ovarian cancer research. Additionally, we explore how polyphenolic compounds, flavonoids, alkaloids, terpenoids, and other natural products modulate autophagy mediated by stress responses, affecting the malignant biological behavior of cancer. Furthermore, we discuss their roles in ovarian cancer therapy. This review emphasizes the importance of natural products as valuable resources in cancer therapeutics, highlighting the need for further exploration of their potential in regulating autophagy. Moreover, it provides novel insights and potential therapeutic strategies in ovarian cancer by utilizing natural products to modulate autophagy.

Phenethyl isothiocyanate and irinotecan synergistically induce cell apoptosis in colon cancer HCT 116 cells in vitro

Irinotecan (IRI), an anticancer drug to treat colon cancer patients, causes cytotoxic effects on normal cells. Phenethyl isothiocyanate (PEITC), rich in common cruciferous plants, has anticancer activities (induction of cell apoptosis) in many human cancer cells, including colon cancer cells. However, the anticancer effects of IRI combined with PEITC on human colon cancer cells in vitro were unavailable. Herein, the aim of this study is to focus on the apoptotic effects of the combination of IRI and PEITC on human colon cancer HCT 116 cells in vitro. Propidium iodide (PI) exclusion and Annexin V/PI staining assays showed that IRI combined with PEITC decreased viable cell number and induced higher cell apoptosis than that of IRI or PEITC only in HCT 116 cells. Moreover, combined treatment induced higher levels of reactive oxygen species (ROS) and Ca2+ than that of IRI or PEITC only. Cells pre-treated with N-acetyl-l-cysteine (scavenger of ROS) and then treated with IRI, PEITC, or IRI combined with PEITC showed increased viable cell numbers than that of IRI or PEITC only. IRI combined with PEITC increased higher caspase-3, -8, and -9 activities than that of IRI or PEITC only by flow cytometer assay. IRI combined with PEITC induced higher levels of ER stress-, mitochondria-, and caspase-associated proteins than that of IRI or PEITC treatment only in HCT 116 cells. Based on these observations, PEITC potentiates IRI anticancer activity by promoting cell apoptosis in the human colon HCT 116 cells. Thus, PEITC may be a potential enhancer for IRI in humans as an anticolon cancer drug in the future.

Curcuminoids as Cell Signaling Pathway Modulators: A Potential Strategy for Cancer Prevention

Despite substantial advancements in curative modern medicine in the last few decades, cancer risk and casualty rates have continued to mount globally. The exact reason for cancer's onset and progression is still unknown. However, skeletal and functional abnormalities in the genetic code are assumed to be the primary cause of cancer. Many lines of evidence reported that some medicinal plants can be utilized to curb cancer cell proliferation with a safe, fruitful, and cost-efficient perspective. Curcuminoid, isolated from Curcuma longa, have gotten a lot of focus due to their anticancer potential as they reduce tumor progression, invasion, and dissemination. Further, they modulated signal transduction routes like MAPK, PI3K/Akt/mTOR, JAK/STAT, and Wnt/β-catenin, etc., and triggered apoptosis as well as actuated autophagy in malignant cells without altering the normal cells, thus preventing cancer progression. Besides, Curcuminoid also regulate the function and expression of anti-tumor and carcinogenic miRNAs. Clinical studies also reported the therapeutic effect of Curcuminoid against various cancer through decreasing specific biomarkers like TNF-α, Bcl-2, COX-2, PGE2, VEGF, IκKβ, and various cytokines like IL-12p70, IL-10, IL-2, IFN-γ levels and increasing in p53 and Bax levels. Thus, in the present review, we abridged the modulation of several signal transduction routes by Curcuminoids in various malignancies, and its modulatory role in the initiation of tumor-suppressive miRNAs and suppression of the oncogenic miRNAs are explored. Additionally, various pharmacokinetic approaches have been projected to address the Curcuminoids bioavailability like the use of piperine as an adjuvant; nanotechnology- based Curcuminoids preparations utilizing Curcuminoids analogues are also discussed.

Curcumin and analogues against head and neck cancer: From drug delivery to molecular mechanisms

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is one of the most life-threatening diseases which also causes economic burden worldwide. To overcome the limitations of traditional therapies, investigation into alternative adjuvant treatments is crucial.

PURPOSE

Curcumin, a turmeric-derived compound, demonstrates significant therapeutic potential in diverse diseases, including cancer. Furthermore, research focuses on curcumin analogues and novel drug delivery systems, offering approaches for improved efficacy. This review aims to provide a comprehensive overview of curcumin's current findings, emphasizing its mechanisms of anti-HNSCC effects and potential for clinical application.

METHOD

An electronic search of Web of Science, MEDLINE, and Embase was conducted to identify literature about the application of curcumin or analogues in HNSCC. Titles and abstracts were screened to identify potentially eligible studies. Full-text articles will be obtained and independently evaluated by two authors to make the decision of inclusion in the review.

RESULTS

Curcumin's clinical application is hindered by poor bioavailability, prompting the exploration of methods to enhance it, such as curcumin analogues and novel drug delivery systems. Curcumin could exhibit anti-cancer effects by targeting cancer cells and modulating the tumor microenvironment in HNSCC. Mechanisms of action include cell cycle arrest, apoptosis promotion, reactive oxygen species induction, endoplasmic reticulum stress, inhibition of epithelial-mesenchymal transition, attenuation of extracellular matrix degradation, and modulation of tumor metabolism in HNSCC cells. Curcumin also targets various components of the tumor microenvironment, including cancer-associated fibroblasts, innate and adaptive immunity, and lymphovascular niches. Furthermore, curcumin enhances the anti-cancer effects of other drugs as adjunctive therapy. Two clinical trials report its potential clinical applications in treating HNSCC.

CONCLUSION

Curcumin has demonstrated therapeutic potential in HNSCC through in vitro and in vivo studies. Its effectiveness is attributed to its ability to modulate cancer cells and interact with the intricate tumor microenvironment. The development of curcumin analogues and novel drug delivery systems has shown promise in improving its bioavailability, thereby expanding its clinical applications. Further research and exploration in this area hold great potential for harnessing the full therapeutic benefits of curcumin in HNSCC treatment.

Curcumin in cancer therapy: Exploring molecular mechanisms and overcoming clinical challenges

Cancer poses a significant global health burden, necessitating the widespread use of chemotherapy and radiotherapy as conventional frontline interventions. Although targeted therapy and immunotherapy have shown remarkable advancements, the challenges of resistance development and severe side effects persist in cancer treatment. Consequently, researchers have actively sought more effective alternatives with improved safety profiles. In recent years, curcumin, a natural polyphenolic phytoalexin, has garnered considerable attention due to its broad spectrum of biological effects. This concise review provides valuable insights into the role of curcumin in cancer therapy, with a focus on elucidating its molecular mechanisms in inducing programmed cell death of tumor cells and suppressing tumor cell metastasis potential. Additionally, we discuss the challenges associated with the clinical application of curcumin and explore current endeavors aimed at overcoming these limitations. By shedding light on the promising potential of curcumin, this review contributes to the advancement of cancer treatment strategies.

Curcumin-loaded mesoporous silica nanoparticles for drug delivery: synthesis, biological assays and therapeutic potential - a review

Curcumin-loaded mesoporous silica nanoparticles (MSNs) have shown promise as drug delivery systems to address the limited pharmacokinetic characteristics of curcumin. Functionalization with folic acid and PEGylation enhance anticancer activity, biocompatibility, stability, and permeability. Co-delivery with other drugs results in synergistically enhanced cytotoxic activity. Environment-responsive MSNs prevent undesirable drug leakage and increase selectivity towards target tissues. This review summarizes the methods of Cur-loaded MSN synthesis and functionalization and their application in various diseases, and also highlights the potential of Cur-loaded MSNs as a promising drug delivery system.

Therapeutic potential of curcumin and its nanoformulations for treating oral cancer

The global incidence of oral cancer has steadily increased in recent years and is associated with high morbidity and mortality. Oral cancer is the most common cancer in the head and neck region, and is predominantly of epithelial origin (i.e. squamous cell carcinoma). Oral cancer treatment modalities mainly include surgery with or without radiotherapy and chemotherapy. Though proven effective, chemotherapy has significant adverse effects with possibilities of tumor resistance to anticancer drugs and recurrence. Thus, there is an imperative need to identify suitable anticancer therapies that are highly precise with minimal side effects and to make oral cancer treatment effective and safer. Among the available adjuvant therapies is curcumin, a plant polyphenol isolated from the rhizome of the turmeric plant Curcuma longa. Curcumin has been demonstrated to have anti-infectious, antioxidant, anti-inflammatory, and anticarcinogenic properties. Curcumin has poor bioavailability, which has been overcome by its various analogues and nanoformulations, such as nanoparticles, liposome complexes, micelles, and phospholipid complexes. Studies have shown that the anticancer effects of curcumin are mediated by its action on multiple molecular targets, including activator protein 1, protein kinase B (Akt), nuclear factor κ-light-chain-enhancer of activated B cells, mitogen-activated protein kinase, epidermal growth factor receptor (EGFR) expression, and EGFR downstream signaling pathways. These targets play important roles in oral cancer pathogenesis, thereby making curcumin a promising adjuvant treatment modality. This review aims to summarize the different novel formulations of curcumin and their role in the treatment of oral cancer.

M, K M, Dey T, Zargar MI, Singh J. Recent advance of herbal medicines in cancer- a molecular approach

Bioactive compounds are crucial for an extensive range of therapeutic uses, and some exhibit anticancer activity. Scientists advocate that phytochemicals modulate autophagy and apoptosis, involved in the underlying pathobiology of cancer development and regulation. The pharmacological aiming of the autophagy-apoptosis signaling pathway using phytocompounds hence offers an auspicious method that is complementary to conventional cancer chemotherapy. The current review aims to explore the molecular level of the autophagic-apoptotic pathway to know its implication in the pathobiology of cancer and explore the essential cellular process as a druggable anticancer target and therapeutic emergence of naturally derived phytocompound-based anticancer agents. The data in the review were collected from scientific databases such as Google search, Web of Science, PubMed, Scopus, Medline, and Clinical Trials. With a broad outlook, we investigated their cutting-edge scientifically revealed and/or searched pharmacologic effects, a novel mechanism of action, and molecular signaling pathway of phytochemicals in cancer therapy. In this review, the evidence is focused on molecular pharmacology, specifically caspase, Nrf2, NF-kB, autophagic-apoptotic pathway, and several mechanisms to understand their role in cancer biology.

Traditional Chinese medicine use in patients with oral cancer: A retrospective longitudinal cohort study in Taiwan

Oral cancer is frequently associated with smoking, alcohol consumption, and betel quid chewing, which are common harmful behaviors observed in certain cohorts of the Taiwanese population. Some reports have explored the potential therapeutic effect of certain herbal remedies on cancer treatments and the outcomes thereof. However, supportive evidence regarding the specific use of traditional Chinese medicine (TCM) in oral cancer treatment is lacking and deserves further investigation. This study measured the use of TCM therapies for oral cancer in a Taiwanese population-based retrospective longitudinal cohort study. The Taiwan National Health Insurance Research Database was utilized to conduct this study. The study population was limited to oral cancer patients diagnosed between 2000 and 2009, which were followed up for at least 5 years. Therapeutic strategies investigated included acupuncture and the Chinese herbs and formula used. Additionally, the frequency of TCM treatment visits, total medical costs, and all-cause mortality were also analyzed. Between 2000 and 2009, a total of 951 patients were diagnosed with various oral cancers. 13.7% of the diagnosed patients utilized TCM treatment measures. The majority of the patients were males. The top 3 common single herbs used were Xuán shēn (Radix Scrophulariae), Shí hú (Herba Dendrobii), and Mài mén dōng (Ophiopogon Japonicus). Then, Gān lù yǐn, Zhī bǎi dì huáng wán, and Sàn zhǒng kuì jiān tāng were the most frequently used herbal formulas. The survival probability was higher in TCM users when compared to non-TCM users in 5- and 12-year all-cause mortality (P < .05). This study explored the use of TCM therapies in oral cancer patients and identified essential information regarding the specifics of conventional herbal medicine used, affiliated medical costs, survival probability, and common symptoms observed in Taiwanese oral cancer patients.

Emerging Role of Autophagy in the Development and Progression of Oral Squamous Cell Carcinoma

Autophagy is a cellular catabolic process, which is characterized by degradation of damaged proteins and organelles needed to supply the cell with essential nutrients. At basal levels, autophagy is important to maintain cellular homeostasis and development. It is also a stress responsive process that allows the cells to survive when subjected to stressful conditions such as nutrient deprivation. Autophagy has been implicated in many pathologies including cancer. It is well established that autophagy plays a dual role in different cancer types. There is emerging role of autophagy in oral squamous cell carcinoma (OSCC) development and progression. This review will focus on the role played by autophagy in relation to different aspects of cancer progression and discuss recent studies exploring the role of autophagy in OSCC. It will further discuss potential therapeutic approaches to target autophagy in OSCC.

Traditional medicinal knowledge of plants used for cancer treatment by communities of mountainous areas of Fez-Meknes-Morocco

Since their existence on earth, humans have used herbal medicine to meet their requirements for medication. The aim of the study: This work refers to a study conducted to carry out an ethnopharmacological survey of medicinal plants used for the treatment of cancer in Fez-Meknes region of Morocco. Material and Methods: To achieve this goal, 300 informants including 237 local people and 63 herbalists. They were requested to fill a survey related questionnaire aiming at the collection of data about the addressed objective. Informants were asked about the vernacular names, parts of medicinal plants used, mode of preparation, route of administration, reference area as well as the ecological distribution. The Relative Frequency of Citation (RFC) and Fidelity Level (FL) were calculated to identify the most effective plants recommended by informants for disease treatment. Results: The findings obtained in the present survey revealed that 94 species belonging to 47 families have been used for cancer treatment in the region of Fez-Meknes. Fruits, leaves, and seeds are the most commonly used plant parts, by the time powder and infusion arethe most common methods used fordrug preparations. Conclusion: This work may contribute towards the society as it provides interesting data on traditional medicinal knowledge of medicinal plantsused to fight cancer.

Total saponins from Tupistra chinensis baker inhibits growth of human gastric cancer cells in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Tupistra chinensis Baker (syn. Rohdea chinensis), an antitumor folk herb mainly distributed in China, its rhizome has been historically used to treat gastric cancer. Studies showed that the steroidal saponins were the main bioactive components in the rhizome of T. chinensis. Our previous studies have confirmed that the steroidal saponins have a variety of anti-tumor activities. However, the underlying anti-tumor mechanism of the total steroidal saponins of T. chinensis (TCS) remains to be revealed.

AIM OF THE STUDY

In the present study, we studied the potential anti-proliferative activity and anti-tumor mechanism of TCS on gastric cancer in vitro and in vivo.

METHODS

In vitro, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was used to detect the proliferation ability of TCS on SGC-7901 cells and AGS cells. Flow cytometry were performed to analyze cell apoptosis, cell cycle, mitochondrial membrane potential and reactive oxygen species expression level. Western blotting was performed to validate the expression of proteins in related pathways. In vivo, a xenograft model was established by injecting SGC-7901 cells into nude mice.

RESULTS

In vitro, TCS inhibited the proliferation of gastric cancer cells. TCS effectively induced apoptosis by PI3K/Akt/mTOR signaling pathway in SGC-7901 cells, and promoted apoptosis via p53-mediated pathway in AGS cells. TCS also exhibited inhibitory activity in blocking the migration of gastric cancer cells. In vivo, TCS significantly inhibited the growth of xenograft tumor.

CONCLUSION

These results indicated that TCS exhibited significant anti-gastric cancer effects in vitro and in vivo.

Targeting Autophagy with Natural Products as a Potential Therapeutic Approach for Cancer

Macro-autophagy (autophagy) is a highly conserved eukaryotic intracellular process of self-digestion caused by lysosomes on demand, which is upregulated as a survival strategy upon exposure to various stressors, such as metabolic insults, cytotoxic drugs, and alcohol abuse. Paradoxically, autophagy dysfunction also contributes to cancer and aging. It is well known that regulating autophagy by targeting specific regulatory molecules in its machinery can modulate multiple disease processes. Therefore, autophagy represents a significant pharmacological target for drug development and therapeutic interventions in various diseases, including cancers. According to the framework of autophagy, the suppression or induction of autophagy can exert therapeutic properties through the promotion of cell death or cell survival, which are the two main events targeted by cancer therapies. Remarkably, natural products have attracted attention in the anticancer drug discovery field, because they are biologically friendly and have potential therapeutic effects. In this review, we summarize the up-to-date knowledge regarding natural products that can modulate autophagy in various cancers. These findings will provide a new position to exploit more natural compounds as potential novel anticancer drugs and will lead to a better understanding of molecular pathways by targeting the various autophagy stages of upcoming cancer therapeutics.

Chemopreventive and Anti-tumor Potential of Natural Products in Oral Cancer

Oral cancer (OC) is a multifactorial disease caused by isolated or combined risk factors related to tobacco, alcohol consumption, and human papillomavirus infection. It is an aggressive pathology with a low five-year survival rate after surgery, chemotherapy, and/or radiotherapy, frequently associated with severe side effects. Drugs with the highest anti-tumor effect are obtained from natural products with diverse biological and molecular activities and potential chemopreventive and anticancer properties. This review summarizes the natural products reported to have the chemopreventive and anti-tumor potential for OC treatment, showing that several of these compounds are promising candidates as chemopreventive agents, and those with the highest anti-tumor potential induce apoptosis and inhibit proliferation and metastasis-related processes. For this reason, natural products have the potential to be important preventive and therapeutic options for OC in the future.

Demethoxycurcumin Suppresses Human Brain Glioblastoma Multiforme GBM 8401 Cell Xenograft Tumor in Nude Mice In Vivo

Demethoxycurcumin (DMC), a derivate of curcumin, has been shown to induce apoptotic cell death in human glioblastoma multiforme GBM 8401 cells via cell cycle arrest and induction of cell apoptosis. However, there is no report showing DMC suppresses glioblastoma multiforme cells in vivo. In the present study, we investigated the effects of DMC on GBM8401 cells in vivo. At first, we established a luciferase-expressing stable clone named GBM 8401/luc2. Second, mice were inoculated subcutaneously with GBM 8401/luc2 cells to generate a xenograft tumor mice model. After inoculation, tumor volume reached 100-120 mm³, and all mice were randomly divided into three groups: Group I was treated with 110 µL phosphate-buffered solution (PBS) containing 0.1% dimethyl sulfoxide, Group II with 30 mg/kg of DMC, and Group III with 60 mg/kg of DMC. Mice from each group were given the oral treatment of DMC by gavage for 21 days. The body weight and tumor volume were recorded every 3 days. DMC significantly decreased the tumor volumes, and 60 mg/kg treatment showed a higher decrease in tumor volumes than that of 30 mg/kg, However, DMC did not affect the body weights. The photons emitted from mice tumors were detected with Xenogen IVIS imaging system, DMC at both doses decreased the total photon flux and 60 mg/kg treatment of DMC has low total photon flux than that of 30 mg/kg. The tumor volumes and weights in 60 mg/kg treatment of DMC were lower than that of 30 mg/kg. Immunohistochemical analysis was used to measure protein expression of tumors and results showed that DMC treatment led to lightly staining with anti-Bcl-2 and -XIAP and 60 mg/kg treatment of DMC has lighter staining with anti-Bcl-2 and -XIAP than that of 30 mg/kg. The higher dose (60 mg/kg) of DMC has higher signals of cleaved-caspase-3 than that of the lower dose (30 mg/kg). Furthermore, the hematoxylin and eosin (H&E) staining of liver tissues showed no significant difference between DMC-treated and control-groups. Overall, these observations showed that DMC suppressed tumor properties in vivo and DMC may be used against human glioblastoma multiforme in the future.

Therapeutic effect of curcumin on oral diseases: A literature review

Curcumin (diferuloylmethane) is a polyphenol compound extracted from the rhizome of the plant Curcuma longa. It has the feature of being a yellow or orange pigment with a variety of biological properties, including anti-inflammation, antioxidation, anti-tumor, anti-bacteria, anti-fungus, and wound healing. Previous studies have reported the role of curcumin in treating different inflammatory diseases and tumors in vitro and in vivo. Recently, it has been demonstrated that curcumin has therapeutic benefits in oral mucosal diseases, periodontal diseases, and mouth neoplasms. In this review, we will focus on the therapeutic effects of curcumin on oral diseases.

The electrical pulse application enhances intra-cellular localization and potentiates cytotoxicity of curcumin in breast cancer cells

Breast cancer is the most common cancer of women, and fifth leading cause of mortality worldwide. Existing breast cancer regimens are costly and produce severe side effects. This highlights a need for the development of efficient novel therapies, which are cost effective and limit side effects. An electrical pulse (EP)-based chemo therapy, known as electrochemotherapy (ECT) using the natural compound curcumin could be an effective alternative. ECT is a non-surgical modality, which produces excellent anti-tumor efficacy at small drug concentrations due to increased uptake of drugs. In clinics, ECT is shown to be effective in treating advanced, recurrent, and metastatic breast cancers, which are refractory to multiple modalities. ECT with curcumin triggers apoptotic cell death in breast cancer cells and could be an effective alternative, due to curcumin's low cost and reduced side-effects. However, there is a lack of studies quantifying the uptake of curcumin in response to EP application. Towards this, we determined the uptake of different curcuminoids (curcumin, desmethoxycurcumin, and bisdemethoxycurcumin) upon EP application and their impact on cell cytotoxicity. Additionally, we studied the combined effect of calcium chloride (CaCl₂) and a curcuminoids (Cur) mixture, based on initial studies suggesting calcium electroporation as a potential inexpensive anti-cancer treatment. Our results indicate EP with Cur increases cellular uptake, cell shrinkage, and cytotoxicity. The EP + Cur resulted in the highest uptake of the bisdemethoxycurcumin. Further, EP also potentiated the cytotoxicity of CaCl₂ and of the Cur and CaCl₂ combination against breast cancer cells and caused apoptosis. Our preliminary data pave the way to further studies on Cur and CaCl₂ combination treating breast cancer.

Autophagy Impairment through Lysosome Dysfunction by Brucine Induces Immunogenic Cell Death (ICD)

Autophagy is an important tightly controlled cellular process that regulates cellular homeostasis and is involved in deciding cell fate such as cell survival and death. The role of autophagy in many intracellular signaling pathways explains its interaction with other different types of cell death, including apoptosis and immunogenic cell death (ICD). The reports showed the complex and intriguing relationship existing between autophagy and immune system signaling pathways. However, the role of autophagy in ICD remains to be clearly elucidated. In this study, we demonstrated that Brucine, a clinically-used small molecule in traditional Chinese medicine, elicited autophagy inhibition. Brucine also triggered cell stress and induced features of ICD, including calreticulin (CRT) exposure and high-mobility group box 1 (HMGB1) release in MDA-MB-231 and CT26 cancer cells. Brucine impaired autolysosomal degradation and exerted a feedback regulation of ERK1/2-mTOR-p70S6K signaling cascade. Brucine-elicited ICD was confirmed by the rejection of CT26 tumor cells, implanted in the mice after vaccination with Brucine-treated CT26 cells. The impaired autophagy contributed to Brucine-induced ICD, as knock-down of Atg5 significantly reduced Brucine-elicited CRT exposure and HMGB1 release. Our results revealed Brucine as a novel autophagy regulator, ICD inducer and hitherto undocumented role of autophagy in ICD. Thus, these results imply the importance of Brucine in cancer immunotherapy. Therefore, Brucine may be used as an ICD inducer and improve its application in cancer treatment with minimized toxicity.

Polyphenol-Mediated Autophagy in Cancer: Evidence of In Vitro and In Vivo Studies

One of the hallmarks of cellular transformation is the altered mechanism of cell death. There are three main types of cell death, characterized by different morphological and biochemical features, namely apoptosis (type I), autophagic cell death (type II) and necrosis (type III). Autophagy, or self-eating, is a tightly regulated process involved in stress responses, and it is a lysosomal degradation process. The role of autophagy in cancer is controversial and has been associated with both the induction and the inhibition of tumor growth. Autophagy can exert tumor suppression through the degradation of oncogenic proteins, suppression of inflammation, chronic tissue damage and ultimately by preventing mutations and genetic instability. On the other hand, tumor cells activate autophagy for survival in cellular stress conditions. Thus, autophagy modulation could represent a promising therapeutic strategy for cancer. Several studies have shown that polyphenols, natural compounds found in foods and beverages of plant origin, can efficiently modulate autophagy in several types of cancer. In this review, we summarize the current knowledge on the effects of polyphenols on autophagy, highlighting the conceptual benefits or drawbacks and subtle cell-specific effects of polyphenols for envisioning future therapies employing polyphenols as chemoadjuvants.

Panax notoginseng for Cerebral Ischemia: A Systematic Review

Panax notoginseng is the most widely used Chinese medicinal herb for the prevention and treatment of ischemic diseases. Its main active ingredients are saponins, including ginsenoside Rb1, ginsenoside Rg1, and notoginsenoside R1, among others. This review provides an up-to-date overview on the pharmacological roles of P. notoginseng constituents in cerebral ischemia. The saponins of P. notoginseng induce a variety of pharmacological effects in the multiscale mechanisms of cerebral ischemic pathophysiology, including anti-inflammatory activity, reduction of oxidative stress, anti-apoptosis, inhibition of amino acid excitotoxicity, reduction of intracellular calcium overload, protection of mitochondria, repairing the blood-brain barrier, and facilitation of cell regeneration. Regarding cell regeneration, P. notoginseng not only promotes the proliferation and differentiation of neural stem cells, but also protects neurons, endothelial cells and astrocytes in cerebral ischemia. In conclusion, P. notoginseng may treat cerebrovascular diseases through multiple pharmacological effects, and the most critical ones need further investigation.

Demethoxycurcumin Inhibits In Vivo Growth of Xenograft Tumors of Human Cervical Cancer Cells

BACKGROUND/AIM

Demethoxycurcumin (DMC), a derivate of curcumin from natural plants, exerts antitumor effects on various human cancer cells in vitro and in vivo. Nevertheless, no reports have disclosed whether DMC can affect the growth of human cervical cancer cells in vivo. Therefore we investigated the antitumor effects of DMC on a HeLa cell xenograft model in nude mice in this study.

MATERIALS AND METHODS

Twenty-four nude mice were subcutaneously injected with HeLa cells. All mice were randomly divided into control, low-dose DMC (30 mg/kg), and high-dose DMC (50 mg/kg) groups and individual mice were treated intraperitoneally accordingly every 2 days.

RESULTS

DMC significantly reduced tumor weights and volumes of HeLa cell xenografts in mice, indicating the suppression of growth of xenograft tumors.

CONCLUSION

These effects and findings might provide evidence for investigating the potential use of DMC as an anti-cervical cancer drug in the future.

Validation of Enhancing Effects of Curcumin on Radiotherapy with F98/FGT Glioblastoma-Bearing Rat Model

Glioblastoma, the most common and aggressive brain tumor with low survival rate, is difficult to be cured by neurosurgery or radiotherapy. Mounting evidence has reported the anti-inflammatory and anticancer effects of curcumin on several types of cancer in preclinical studies and clinical trials. To our knowledge, there is no platform or system that could be used to effectively and real-timely evaluate the therapeutic efficacy of curcumin for glioblastoma multiforme (GBM). In this study, we constructed a lentivirus vector with triple-reporter genes (Fluc/GFP/tk) and transduced into rat F98 glioblastoma cells to establish an orthotopic F98/FGT glioma-bearing rat model. In the model, the therapeutic efficacies for curcumin alone, radiation alone, and their combination were evaluated via noninvasive bioluminescent imaging and overall survival measurements. At the cell level, curcumin is capable of causing a G2/M cell cycle arrest and sensitizing the F98 cells to radiation. In animal model, curcumin synergistically enhances the effects of radiotherapy on suppressing the growth of both transplanted glioma cells and in situ brain tumors, and extending the overall survival periods longer than those of curcumin alone and radiation alone treatments. In conclusion, we have demonstrated that curcumin may serve as a novel radiosensitizer to combine with radiotherapy using the triple-reporter F98/FGT animal model for effective and simultaneous evaluation of therapeutic efficacy.

Partitioned Extracts of Bauhinia championii Induce G0/G1 Phase Arrest and Apoptosis in Human Colon Cancer Cells

Bauhinia championii (Benth.) is one of the commonly used herbs in Taiwan. The stem of this plant has been used to treat epigastria pain and rheumatoid arthritis. However, the antitumor activities of this herb have never been reported. This study aims to investigate the mechanism of anticancer activity of the extracts from B. championii (BC). BC was fractionated with a series of organic solvents, including n-hexane (H), ethyl acetate (EA), 1-butanol (B), and water (W). We first investigated the effects of BC-H, BC-EA, BC-B and BC-W partitioned fraction on cell viability. In HCT 116 colon cancer cell lines, BC-EA showed the highest inhibition of cell viability and changed the morphology of cells. With dose- and time-dependent manners, BC-EA inhibited the proliferation of HCT 116 cells by inducing apoptosis and G₀/G₁ phase arrest of cell cycle. To determine the underlying mechanisms, down-regulated CDK2, Cyclin D, and Cyclin E and up-regulated p16, p21, and p53 may account for the cell cycle arrest, while the apoptotic effect of BC-EA may attribute to increased intracellular Ca2+, loss of mitochondria membrane potential (ΔΨm), increase of Bax, Bak, puma, and AIF, and decrease of Bcl-2. Furthermore, the inactivation of Ras signaling pathway by BC-EA also contributed to its apoptotic effect on HCT 116. Our study demonstrates that BC-EA not only inhibits cell growth but also induces apoptosis through inhibiting Ras signal pathway and increasing p53 expression levels. We suggest that BC-EA may be a new dietary supplement and a useful tool to search for therapeutic candidates against colon cancer.

Dual Targeting of the p38 MAPK-HO-1 Axis and cIAP1/XIAP by Demethoxycurcumin Triggers Caspase-Mediated Apoptotic Cell Death in Oral Squamous Cell Carcinoma Cells

Demethoxycurcumin (DMC) is a curcumin analogue with better stability and higher aqueous solubility than curcumin after oral ingestion and has the potential to treat diverse cancers, including oral squamous cell carcinoma (OSCC). The aim of this study was to investigate the anticancer effects and underlying mechanisms of DMC against OSCC. We found that DMC suppressed cell proliferation via simultaneously inducing G2/M-phase arrest and cell apoptosis. Mechanistic investigations found that the downregulation of cellular IAP 1 (cIAP1)/X-chromosome-linked IAP (XIAP) and upregulation of heme oxygenase-1 (HO-1) were critical for DMC-induced caspase-8/-9/-3 activation and apoptotic cell death. Moreover, p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK)1/2 were activated by DMC treatment in OSCC cells, and only the inhibition of p38 MAPK significantly abolished DMC-induced HO-1 expression and caspase-8/-9/-3 activation. The analyses of clinical datasets revealed that patients with head and neck cancers expressing high HO-1 and low cIAP1 had the most favorable prognoses. Furthermore, a combinatorial treatment of DMC with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, gefitinib, significantly enhanced the inhibitory effect of gefitinib on the proliferation of OSCC cells. Overall, the current study supported a role for DCM as part of a therapeutic approach for OSCC through suppressing IAPs and activating the p38-HO-1 axis.

Chinese Herbal Medicine-Based Cancer Therapy: Novel Anticancer Agents Targeting MicroRNAs to Regulate Tumor Growth and Metastasis

MicroRNAs, small non-coding RNA molecules, have gained a reputation of the most substantial regulators in gene network with the ability to down-regulate their targets. Accumulating evidence shifted insight toward microRNAs regulation as the key element of cancer initiation, development, and aggression. Recent studies have attached the importance of traditional Chinese medicine (TCM) to the treatment of various cancers, and the functional natural compounds have been considered as novel anticancer agents to directly inhibit tumor progression. In more recent decades, a wide range of biologically active components of TCM has gained increasing attention to their applications in the modulation of microRNAs. This review is on the purpose of demonstrating the significance of TCM bioactive ingredients in microRNAs regulation for cancer treatment according to the reports mainly in the recent six years, providing the evidence of efficient Chinese herbal medicine-based therapy and effective pro-diagnosis focusing on microRNAs expression of cancer patients.

Curcumin Management of Myocardial Fibrosis and its Mechanisms of Action: A Review

Myocardial fibrosis is implicated as a leading risk factor for heart failure, arrhythmia, and sudden death after cardiac injury, as the excessive interstitial extracellular matrix impedes heart contraction and electrical conduction. Complicated mechanisms involving oxidative stress, pro-inflammatory cytokines, chemokine families, NLRP3 inflammasomes, growth factors, and non-coding RNAs participate in cardiac fibrogenesis and make it difficult to designate specific and effective therapies. Oriental herbs have been popular for thousands of years in the health care of Asian residents, due to their multi-targeted, multi-faceted approaches and their multi-functional effects in fighting difficult and complicated diseases, including cardiovascular disorders such as myocardial fibrosis. Curcumin, a natural polyphenol and yellow pigment obtained from the spice turmeric, was found to have strong anti-oxidant and anti-inflammatory properties. Increasing evidence has shown that curcumin can be used to prevent and treat myocardial fibrosis, when the myocardium suffers pathological pro-fibrotic changes in vivo and in vitro. The present review focuses on recent studies elucidating the mechanisms of curcumin in treating different pathologic conditions, including ischemia, hypoxia/reoxygenation, pressure or volume overload, and hyperglycemia or high-fat-induced cardiac fibrosis. Novel analogs such as C66, B2BrBC, Y20, and J17 have been designed to maximize the therapeutic potentials of curcumin. These optimized curcumin analogs with improved bioavailability and pharmacokinetic profiles need to be clinically verified before curcumin could be recommended for the treatment of myocardial fibrosis.

Curcumin: Novel Treatment in Neonatal Hypoxic-Ischemic Brain Injury

Hypoxic-ischemic encephalopathy (HIE) is a major cause of mortality and morbidity in neonates, with an estimated global incidence of 3/1,000 live births. HIE brain damage is associated with an inflammatory response and oxidative stress, resulting in the activation of cell death pathways. At present, therapeutic hypothermia is the only clinically approved treatment available for HIE. This approach, however, is only partially effective. Therefore, there is an unmet clinical need for the development of novel therapeutic interventions for the treatment of HIE. Curcumin is an antioxidant reactive oxygen species scavenger, with reported anti-tumor and anti-inflammatory activity. Curcumin has been shown to attenuate mitochondrial dysfunction, stabilize the cell membrane, stimulate proliferation, and reduce injury severity in adult models of spinal cord injury, cancer, and cardiovascular disease. The role of curcumin in neonatal HIE has not been widely studied due to its low bioavailability and limited aqueous solubility. The aim of this study was to investigate the effect of curcumin treatment in neonatal HIE, including time of administration and dose-dependent effects. Our results indicate that curcumin administration prior to HIE in neonatal mice elevated cell and tissue loss, as well as glial activation compared to HI alone. However, immediate post-treatment with curcumin was significantly neuroprotective, reducing grey and white matter tissue loss, TUNEL+ cell death, microglia activation, reactive astrogliosis, and iNOS oxidative stress when compared to vehicle-treated littermates. This effect was dose-dependent, with 200 μg/g body weight as the optimal dose-regimen, and was maintained when curcumin treatment was delayed by 60 or 120 min post-HI. Cell proliferation measurements showed no changes between curcumin and HI alone, suggesting that the protective effects of curcumin on the neonatal brain following HI are most likely due to curcumin’s anti-inflammatory and antioxidant properties, as seen in the reduced glial and iNOS activity. In conclusion, this study suggests curcumin as a potent neuroprotective agent with potential for the treatment of HIE. The delayed application of curcumin further increases its clinical relevance.

Naturally occurring anti-cancer compounds: shining from Chinese herbal medicine

Numerous natural products originated from Chinese herbal medicine exhibit anti-cancer activities, including anti-proliferative, pro-apoptotic, anti-metastatic, anti-angiogenic effects, as well as regulate autophagy, reverse multidrug resistance, balance immunity, and enhance chemotherapy in vitro and in vivo. To provide new insights into the critical path ahead, we systemically reviewed the most recent advances (reported since 2011) on the key compounds with anti-cancer effects derived from Chinese herbal medicine (curcumin, epigallocatechin gallate, berberine, artemisinin, ginsenoside Rg3, ursolic acid, silibinin, emodin, triptolide, cucurbitacin B, tanshinone I, oridonin, shikonin, gambogic acid, artesunate, wogonin, β-elemene, and cepharanthine) in scientific databases (PubMed, Web of Science, Medline, Scopus, and Clinical Trials). With a broader perspective, we focused on their recently discovered and/or investigated pharmacological effects, novel mechanism of action, relevant clinical studies, and their innovative applications in combined therapy and immunomodulation. In addition, the present review has extended to describe other promising compounds including dihydroartemisinin, ginsenoside Rh2, compound K, cucurbitacins D, E, I, tanshinone IIA and cryptotanshinone in view of their potentials in cancer therapy. Up to now, the evidence about the immunomodulatory effects and clinical trials of natural anti-cancer compounds from Chinese herbal medicine is very limited, and further research is needed to monitor their immunoregulatory effects and explore their mechanisms of action as modulators of immune checkpoints.

Role of Autophagy on Heavy Metal-Induced Renal Damage and the Protective Effects of Curcumin in Autophagy and Kidney Preservation

Curcumin is a hydrophobic polyphenol compound extracted from the rhizome of turmeric. The protective effect of curcumin on kidney damage in multiple experimental models has been widely described. Its protective effect is mainly associated with its antioxidant and anti-inflammatory properties, as well as with mitochondrial function maintenance. On the other hand, occupational or environmental exposure to heavy metals is a serious public health problem. For a long time, heavy metals-induced nephrotoxicity was mainly associated with reactive oxygen species overproduction and loss of endogenous antioxidant activity. However, recent studies have shown that in addition to oxidative stress, heavy metals also suppress the autophagy flux, enhancing cell damage. Thus, natural compounds with the ability to modulate and restore autophagy flux represent a promising new therapeutic strategy. Furthermore, it has been reported in other renal damage models that curcumin’s nephroprotective effects are related to its ability to regulate autophagic flow. The data indicate that curcumin modulates autophagy by classic signaling pathways (suppression of protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and/or by stimulation of adenosine monophosphate-activated protein kinase (AMPK) and extracellular signal-dependent kinase (ERK) pathways). Moreover, it allows lysosomal function preservation, which is crucial for the later stage of autophagy. However, future studies of autophagy modulation by curcumin in heavy metals-induced autophagy flux impairment are still needed.

Amentoflavone Effectively Blocked the Tumor Progression of Glioblastoma via Suppression of ERK/NF- κ B Signaling Pathway

Glioblastoma is the most common primary malignant tumor of the central nervous system, with an annual incidence of 5.26 per 100000 people. The clinical outcome of standard therapy and the survival rate remain poor; therefore, there is an unmet need for a new strategy to treat this lethal disease. Although amentoflavone was known to have anticancer potential in various types of cancers, its antiglioblastoma ability and mechanism remain unrecognized. We demonstrated that amentoflavone may suppress glioblastoma invasion and migration by transwell assay. Moreover, we established NF- κ B reporter gene system and used that for verifying NF- κ B inhibition efficacy of amentoflavone on in vitro and in vivo studies. Here, we indicated that amentoflavone not only diminished NF- κ B activation, but also reduced NF- κ B-mediated downstream oncogenes expression, such as MMP-2, MMP-9, XIAP, cyclinD1 and VEGF, which was elucidated by Western blot and immunohistochemistry (IHC). Tumor growth inhibition and NF- κ B reduction was found in the amentoflavone treatment group, which was revealed by the glioblastoma-bearing animal model. In this study, we also used ERK inhibitor and NF- κ B inhibitor (QNZ) to confirm whether the beneficial result of amentoflavone on glioblastoma was mainly regulated by blockage of ERK/NF- κ B signaling. In summary, ERK/NF- κ B signaling pathway has a role in the inhibition of tumor growth by amentoflavone in glioblastoma.

[Effect of brazilin on apoptosis and autophagy of tongue cancer Tca8113 cells and its molecular mechanism]

OBJECTIVE

To investigate the effects of brazilin on the proliferation, apoptosis and autophagy of human tongue squamous cell carcinoma Tca8113 cells in vitro and explore its molecular mechanism.

METHODS

The changes in the proliferation, morphology and apoptosis of Tca8113 cells in response to brazilin treatment were detected using MTT assay, Hoechst33342 staining, and Annexin V/PI double staining, respectively. The expressions of apoptosis-related protein Bax, Bcl-2, cleaved caspase-3 and autophagy-related proteins p-AMPK, p-mTOR, LC3B, and p62 in the treated cells were detected using Western blotting. The effect of treatment with both the AMPK pathway inhibitor and brazilin on the expressions of the pathway-related proteins p-AMPK, p-mTOR, and LC3B was assessed.

RESULTS

MTT assay showed that brazilin significantly inhibited the proliferation of Tca8113 cells with an IC50 of 31.17 μmol/L at 24 h. Hoechst33342 staining showed that brazilin induced apoptotic morphological changes in Tca8113 cells in a concentration-dependent manner. Treatment with different concentrations of brazilin resulted in increased apoptosis in the cells. Brazilin obviously inhibited the expression of Bcl-2, p62 and p-mTOR and enhanced the expressions of Bax, cleaved caspase-3, LC3B and p-AMPK. The AMPK pathway inhibitor significantly inhibited the increase in p-AMPK and LC3B expressions and the decrease in p-mTOR expression induced by brazilin.

CONCLUSIONS

Brazilin can inhibit the proliferation and promote apoptosis in Tca8113 cells and at the same time induces autophagy in the cells through the AMPK/mTOR pathway.

Efficacy of curcumin for management of oral submucous fibrosis: a systematic review of randomized clinical trials

OBJECTIVES

Oral submucous fibrosis (OSF) is a chronic debilitating disease that has a high risk of malignant transformation. Management of OSF is quite challenging, with no definitive cure being available. This systematic review assessed the available evidence for using curcumin for pain alleviation and clinical improvement in patients with OSF.

STUDY DESIGN

A comprehensive search of PubMed/Medline, Scopus, and ISI Web of Science databases was conducted to identify all relevant clinical trials comparing patients receiving curcumin treatment to active and/or nonactive controls for the treatment of OSF.

RESULTS

Six clinical trials comprising 298 patients were included. All studies found curcumin to be effective in the management of OSF. Three studies found significantly higher improvement in burning sensation in the curcumin group compared with controls, whereas 3 other studies found comparable results. With regard to clinical signs, 2 studies showed better improvement in mouth opening in the curcumin group; 3 studies reported no differences in effectiveness; and only 1 study found curcumin to be inferior to conventional therapy.

CONCLUSIONS

The available evidence remains inconclusive but suggests that curcumin is a promising effective treatment option for the management of patients with OSF. Further well-designed clinical trials with large sample sizes and adequate follow-up periods are warranted.

Bufalin Induces Apoptotic Cell Death in Human Nasopharyngeal Carcinoma Cells through Mitochondrial ROS and TRAIL Pathways

The aim of this study was to investigate the effects of bufalin on human nasopharyngeal carcinoma NPC-TW 076 cells in vitro. Bufalin is a cardiotonic steroid and a key active ingredient of the Chinese medicine ChanSu. The extracts of Chansu are used for various cancer treatments in China. In the present study, bufalin induced cell morphological changes, decreased total cell viability and induced G2/M phase arrest of cell cycle in NPC-TW 076 cells. Results also indicated that bufalin induced chromatin condensation (cell apoptosis) and DNA damage by DAPI staining and comet assay, respectively. The induced apoptotic cell death was further confirmed by annexin-V/PI staining assay. In addition, bufalin also increased ROS and Ca[Formula: see text] production and decreased the levels of [Formula: see text]. Furthermore, the alterations of ROS, ER stress and apoptosis associated protein expressions were investigated by Western blotting. Results demonstrated that bufalin increased the expressions of ROS associated proteins, including SOD (Cu/Zn), SOD2 (Mn) and GST but decreased that of catalase. Bufalin increased ER stress associated proteins (GRP78, IRE-1[Formula: see text], IRE-1[Formula: see text], caspase-4, ATF-6[Formula: see text], Calpain 1, and GADD153). Bufalin increased the pro-apoptotic proteins Bax, and apoptotic associated proteins (cytochrome c, caspase-3, -8 and -9, AIF and Endo G) but reduced anti-apoptotic protein Bcl-2 in NPC-TW 076 cells. Furthermore, bufalin elevated the expressions of TRAIL-pathway associated proteins (TRAIL, DR4, DR5, and FADD). Based on these findings, we suggest bufalin induced apoptotic cell death via caspase-dependent, mitochondria-dependent and TRAIL pathways in human nasopharyngeal carcinoma NPC-TW 076 cells.

Novel Combination of Arsenic Trioxide (As2O3) Plus Resveratrol in Inducing Programmed Cell Death of Human Neuroblastoma SK-N-SH Cells

AIM

Arsenic trioxide (As₂O₃), known as pi-shuang and the most toxic compound in traditional Chinese medicine, has been used as an antitumor agent for thousands of years. Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a natural phenol that has significant anti-bacterial, anti-fungaI and antiaging activities. Our study aimed to examine the combined anticancer effects of As₂O₃ and resveratrol against human neuroblastoma SK-N-SH cells, and elucidate the underlying intracellular signaling.

MATERIALS AND METHODS

SK-N-SH cells were treated with an extremely low-dose (2-4 μM) of As₂O₃ alone or combined with 75 μg/ml resveratrol for further comparisons. Cell viability, apoptotic signaling as well as synergistic cytotoxic effects were estimated using the MTT assay, microscopy observation, flow cytometric analysis for loss of mitochondrial membrane potential (MMP) and reactive oxygen species (ROS), and typical quantitative western blotting analysis. Student's t-test, and one- and two-way analysis of variance (ANOVA) were used for examination of significant differences.

RESULTS

The combined treatment was more effective than single treatment of As₂O₃ or resveratrol alone in suppressing cell viability, which correlated with the elevation of ROS levels. The intracellular mechanisms of cytotoxicity of As₂O₃ plus resveratrol were revealed as ROS accumulation and relative decrease of MMP, leading to activation of caspase-3 and -9, but not of caspase-1, -7 and-8. Combination treatment reduced the expression of B-cell lymphoma 2 (BCL2), BH3 interacting domain death agonist (BID), and BCL-x/L.

CONCLUSION

Combined treatment at extremely low concentration of two agents from natural products, As₂O₃ and resveratrol, has high potential as a cocktail of anticancer drugs for neuroblastoma.

Sandensolide Induces Oxidative Stress-Mediated Apoptosis in Oral Cancer Cells and in Zebrafish Xenograft Model

Presently, natural sources and herbs are being sought for the treatment of human oral squamous cell carcinoma (OSCC) in order to alleviate the side effects of chemotherapy. This study investigates the effect of sandensolide, a cembrane isolated from Sinularia flexibilis, to inhibit human OSCC cell growth with the aim of developing a new drug for the treatment of oral cancer. In vitro cultured human OSCC models (Ca9.22, SCC9 and HSC-3 cell lines) and oral normal cells (HGF-1), as well as a zebrafish xenograft model, were used to test the cytotoxicity of sandensolide (MTT assay), as well as to perform cell cycle analysis and Western blotting. Both the in vitro bioassay and the zebrafish xenograft model demonstrated the anti-oral cancer effect of sandensolide. Moreover, sandensolide was able to significantly suppress colony formation and induce apoptosis, as well as cell cycle arrest, in OSCC by regulating multiple key proteins. Induction of reactive oxygen species (ROS) was observed in sandensolide-treated oral cancer cells. However, these apoptotic changes were rescued by NAC pretreatment. These findings contribute to the knowledge of the model of action of sandensolide, which may induce oxidative stress-mediated cell death pathways as a potential agent in oral cancer therapeutics.