Curcumin Induces Autophagy, Apoptosis, and Cell Cycle Arrest in Human Pancreatic Cancer Cells

Acid-Unlocked Two-Layer Ca-Loaded Nanoplatform to Interfere With Mitochondria for Synergistic Tumor Therapy

Background

The development of selective formulations able to target and kill tumor cells without the application of external energy has shown great promise for anti-tumor therapy.

Methods

Here, we report a "nanobomb" that explosively increases Ca content within cells. It can selectively release Ca2+ and generate H2O2 in the tumor microenvironment (TME) by acid-triggered degradation of the two-layer protective shell (ie, unlocking the "double-lock"). This material, termed CaO2@ZIF8:CUR@PAA, comprises a CaO2 core coated with the ZIF-8 framework, which was then loaded with curcumin (CUR) and coated again with polyacrylic acid (PAA).

Results

Under the slightly acidic conditions of the TME, the PAA shell (first lock) breaks down first exposing CaO2@ZIF8 and CUR inside the cell. Then, ZIF8 (second lock) is degraded in response to acid to deposit Ca2+, and H2O2. CUR can promote the release of Ca2+ from the endoplasmic reticulum to the cytoplasm, inhibit the outflow of Ca2+, and accumulates a large amount of Ca2+ intracellularly together with exogenous Ca2+ (calcium storms). The powerful calcium storm that causes mitochondrial dysfunction. The presence of a large amount of exogenous H2O2 causes further oxidative damage to tumor cell membranes and mitochondria where intracellular ROS production far exceeds clearance. CaO2@ZIF8:CUR@PAA NPs can induce cell S cycle arrest and apoptosis to inhibit tumor multiplication and growth. Oxidative damage-triggered immunogenic cell death (ICD) in turn leads to the polarization of macrophages to the M1 phenotype, inducing immunogenic cell death and inhibiting tumor cell proliferation and metastasis.

Discussion

The acid two-step unlocking nanoplatform is a therapeutic modality that combines calcium storm and oxidative damage. The mode triggers apoptosis leading to ICD of tumor cells. The material induces cycle blockade during treatment to inhibit cell proliferation. Robust in vitro and in vivo data demonstrate the efficacy of this approach and CaO2@ZIF8:CUR@PAA as an anticancer platform, paving the way for nanomaterials in immune-triggered cancer therapy.

Theabrownin: a dietary nutraceutical with diverse anticancer mechanisms

Cancer, a highly deadly disease, necessitates safe, cost-effective, and readily accessible treatments to mitigate its impact. Theabrownin (THBR), a polyphenolic pigment found in Pu-erh tea, has garnered attention for its potential benefits in memory, liver health, and inflammation control. By observing different biological activities of THBR, recently researchers have unveiled THBR's promising anticancer properties across various human cancer types. By examining existing studies, it is evident that THBR demonstrates substantial potential in inhibiting cell proliferation and reducing tumour size with minimal harm to normal cells. These effects are achieved through the modulation of key molecular markers such as Bcl-2, Bax, various Caspases, Poly (ADP-ribose) polymerase cleavage (Cl-PARP), and zinc finger E box binding homeobox 1 (ZEB 1). This review aims to provide in-depth insights into THBR's role in cancer research. This review also elucidates the underlying anticancer mechanisms of THBR, offering promise as a novel anticancer drug to alleviate the global cancer burden.

Curcumin-Loaded Maltodextrin-Based Proniosomes Potentially Effective against Gemcitabine-Resistant Cholangiocarcinoma

Cholangiocarcinoma (CCA) or bile-duct cancer is most prevalent in Southeast Asian counties including Thailand. Patients present at an advanced stage when the cancer is often drug resistant, leading to chemotherapy failure. Curcumin has therapeutic potential with various anticancer properties. However, its effectiveness is limited by its low bioavailability, poor solubility, and instability. This study aimed to synthesize, characterize and evaluate the efficacy of curcumin-loaded maltodextrin-based proniosomes (CMPNs) to overcome the limitations of curcumin for treating gemcitabine-resistant CCA cells (KKU-213BGemR) in vitro and in vivo. Various proniosome formulations were developed and tested for their efficacy against KKU-213BGemR cells using cytotoxicity, clonogenic, migration, and invasion assays. The potential mechanism involving in cell cycle arrest, apoptosis, expression of C/EBP homologous protein (CHOP), a pro-apoptotic transcription factor, and other apoptotic markers were investigated. The results showed that nanoscale CMPNs exhibited a good curcumin loading capacity and an entrapment efficiency of over 97%, as well as good stability and permeability through porcine esophageal mucosa. CMPNs inhibited proliferation, colony formation, migration/invasion and induced apoptosis in KKU-213BGemR cells. Western blot analysis revealed CMPNs significantly increased CHOP, the cleavage products of poly(ADP-ribose) polymerase-1 (PARP-1), apoptosis-inducing factor, and caspase-3 expression in KKU-213BGemR cells. A xenograft model revealed that 62.5 mg/kg BW CMPNs significantly suppressed proliferating cell nuclear antigen and increased CHOP-mediated apoptosis, leading to significantly reduced tumor volume. In conclusion, CMPNs effectively overcome limitations of curcumin and offer an effective strategy against gemcitabine-resistant CCA via CHOP-mediated pathways. These proniosomes are promising as an alternative treatment approach for CCA.

Curcumin-loaded emulsome nanoparticles induces apoptosis through p53 signaling pathway in pancreatic cancer cell line PANC-1

Pancreatic cancer is a global health problem with a poor prognosis, limited treatment options and low survival rates of patients. Thus, the exploration of novel treatment approaches is crucial. Curcumin shows promise in pancreatic cancer. Curcumin has anticancer properties promoting apoptosis through the p53 pathway. However, adverse effects and low bioavailability are curcumin's main drawbacks and its delivery by nanoparticles could improve its effectiveness as a treatment option. Curcumin-loaded emulsome nanoparticles (CurEm) have shown promise in colorectal, hepatocellular, and prostate cancers. This study aims to evaluate the anticancer potential of CurEm in pancreatic cancer cell line PANC-1. The cytotoxic effects of CurEm on PANC-1 cells show cytotoxicity in dose and time-dependent manner. The selected dose 30 μM CurEm resulted spheroidal morphology in PANC-1 cells and colony forming and scratch assay conducted demonstrated significant growth inhibition and decrease in migration ability, respectively. Cell cycle analysis shows that CurEm induces G2/M arrest in PANC-1 cells. CurEm-treated PANC-1 cells showed a significant increase in p53 and Caspase 3 genes, while a significant decrease in Bcl-2 genes compared to untreated group. Western blot results showed parallel results to qPCR analysis for Bcl-2 protein levels. Interestingly, we saw low p53 protein levels in CurEm-treated PANC-1 cells. These findings shed light on the potential of CurEm as an effective and stable therapeutic approach for pancreatic cancer.

A smart tablet-phone-based high-performance pancreatic cancer cell biosensing system for drug screening

Exploring more efficient pancreatic cancer drug screening platforms is of significant importance for accelerating the drug development process. In this study, we developed a high-sensitivity bioluminescence system based on smartphones and smart tablets, and constructed a pancreatic cancer drug screening platform (PCDSP) by combining the pancreatic cancer cell sensing model (PCCSM) on the multiwell plates (MTP). A smart tablet was used as the light source and a smartphone as the colorimetric sensing device. The smartphone dynamically controls the color and brightness displayed on the smart tablet to achieve lower LOD and wider detection ranges. We constructed PCCSM for 24 h, 48 h, and 72 h , and performed colorimetric experiments using both PCDSP and a commercial plate reader (CPR). The results showed that the PCDSP had a lower LOD than that of CPR. Moreover, PCDSP even exhibited a lower LOD for 24 h PCCSM testing compared to CPR for 48 h PCCSM testing, effectively shortening the drug evaluation process. Additionally, the PCDSP offers higher portability and efficiency compared with CPR, making it a promising platform for efficient pancreatic cancer drug screening.

Promising and challenging phytochemicals targeting LC3 mediated autophagy signaling in cancer therapy

BACKGROUND

Phytochemicals possess a wide range of anti-tumor properties, including the modulation of autophagy and regulation of programmed cell death. Autophagy is a critical process in cellular homeostasis and its dysregulation is associated with several pathological conditions, such as cancer, neurodegenerative diseases, and diabetes. In cancer, autophagy plays a dual role by either promoting tumor growth or suppressing it, depending on the cellular context. During autophagy, autophagosomes engulf cytoplasmic components such as proteins and organelles. LC3-II (microtubule-associated protein 1 light chain 3-II) is an established marker of autophagosome formation, making it central to autophagy monitoring in mammals.

OBJECTIVE

To explore the regulatory role of phytochemicals in LC3-mediated autophagy and their potential therapeutic impact on cancer. The review emphasizes the involvement of autophagy in tumor promotion and suppression, particularly focusing on autophagy-related signaling pathways like oxidative stress through the NRF2 pathway, and its implications for genomic stability in cancer development.

METHODS

The review focuses on a comprehensive analysis of bioactive compounds including Curcumin, Celastrol, Resveratrol, Kaempferol, Naringenin, Carvacrol, Farnesol, and Piperine. Literature on these compounds was examined to assess their influence on autophagy, LC3 expression, and tumor-related signaling pathways. A systematic literature search was conducted across databases including PubMed, Scopus, and Web of Science from inception to 2023. Studies were selected from prominent databases, focusing on their roles in cancer diagnosis and therapeutic interventions, particularly in relation to LC3-mediated mechanisms.

RESULTS

Phytochemicals have been shown to modulate autophagy through the regulation of LC3-II levels and autophagic flux in cancer cells. The interaction between autophagy and other cellular pathways such as oxidative stress, inflammation, and epigenetic modulation highlights the complex role of autophagy in tumor biology. For instance, Curcumin and Resveratrol have been reported to either induce or inhibit autophagy depending on cancer type, influencing tumor progression and therapeutic responses.

CONCLUSION

Targeting autophagy through LC3 modulation presents a promising strategy for cancer therapy. The dual role of autophagy in tumor suppression and promotion, however, necessitates careful consideration of the context in which autophagy is induced or inhibited. Future research should aim to delineate these context-specific roles and explore how phytochemicals can be optimized for therapeutic efficacy. Novel therapeutic strategies should focus on the use of bioactive compounds to fine-tune autophagy, thereby maximizing tumor suppression and inducing programmed cell death in cancer cells.

Natural Autophagy Activators to Fight Age-Related Diseases

The constant increase in the elderly population presents significant challenges in addressing new social, economic, and health problems concerning this population. With respect to health, aging is a primary risk factor for age-related diseases, which are driven by interconnected molecular hallmarks that influence the development of these diseases. One of the main mechanisms that has attracted more attention to aging is autophagy, a catabolic process that removes and recycles damaged or dysfunctional cell components to preserve cell viability. The autophagy process can be induced or deregulated in response to a wide range of internal or external stimuli, such as starvation, oxidative stress, hypoxia, damaged organelles, infectious pathogens, and aging. Natural compounds that promote the stimulation of autophagy regulatory pathways, such as mTOR, FoxO1/3, AMPK, and Sirt1, lead to increased levels of essential proteins such as Beclin-1 and LC3, as well as a decrease in p62. These changes indicate the activation of autophagic flux, which is known to be decreased in cardiovascular diseases, neurodegeneration, and cataracts. The regulated administration of natural compounds offers an adjuvant therapeutic alternative in age-related diseases; however, more experimental evidence is needed to support and confirm these health benefits. Hence, this review aims to highlight the potential benefits of natural compounds in regulating autophagy pathways as an alternative approach to combating age-related diseases.

Autophagy in Its (Proper) Context: Molecular Basis, Biological Relevance, Pharmacological Modulation, and Lifestyle Medicine

Autophagy plays a critical role in maintaining cellular homeostasis and responding to various stress conditions by the degradation of intracellular components. In this narrative review, we provide a comprehensive overview of autophagy's cellular and molecular basis, biological significance, pharmacological modulation, and its relevance in lifestyle medicine. We delve into the intricate molecular mechanisms that govern autophagy, including macroautophagy, microautophagy and chaperone-mediated autophagy. Moreover, we highlight the biological significance of autophagy in aging, immunity, metabolism, apoptosis, tissue differentiation and systemic diseases, such as neurodegenerative or cardiovascular diseases and cancer. We also discuss the latest advancements in pharmacological modulation of autophagy and their potential implications in clinical settings. Finally, we explore the intimate connection between lifestyle factors and autophagy, emphasizing how nutrition, exercise, sleep patterns and environmental factors can significantly impact the autophagic process. The integration of lifestyle medicine into autophagy research opens new avenues for promoting health and longevity through personalized interventions.

Network pharmacology and molecular docking reveal the mechanisms of curcumin activity against esophageal squamous cell carcinoma

Background: Curcumin (CUR), an effective traditional Chinese medicinal extract, displays good anti-cancer activity against various cancers. Nevertheless, the impacts and fundamental mechanisms of CUR to treat esophageal squamous cell carcinoma (ESCC) yet to be comprehensively clarified. This study examined the suppressive impacts of CUR on ESCC. Methods: For a comprehensive understanding of the effect of CUR in ESCC. The CUR targets and ESCC-related genes were identified respectively, and the intersection targets between CUR and ESCC were acquired. Then, we examined the intersection targets and discovered genes that were expressed differently in ESCC. Using DAVID, enrichment analyses were conducted on the targets of CUR-ESCC. The STRING database and Cytoscape v.3.9.1 were utilized to build networks for protein-protein interaction (PPI) and drug-target-pathway. Furthermore, the interactions between CUR and its core targets were confirmed by molecular docking studies. To confirm the effects of CUR on ESCC cells, in vitro experiments were finally conducted. Results: Overall, 47 potential CUR targets for ESCC treatment were identified. The KEGG pathway enrichment analysis identified 61 signaling pathways, primarily associated with the FoxO signaling, the cell cycle, cellular senescence, the IL-17 signaling pathway which play important roles in ESCC progression. In the PPI network and the docking results identified CHEK1 and CDK6 as the core targets that positively associated with ESCC survival. CUR arrested ESCC cells at the G2/M and S phases, as shown by flow cytometry. Colony formation and CCK8 assays showed that CUR can inhibit the proliferative ability of ESCC cells. The Transwell invasion results validated that CUR can significantly inhibit the invasion rates of ESCC cells. Conclusion: Collectively, these findings indicate that CUR exhibits pharmacological effects on multiple targets and pathways in ESCC.

Recent Trends in Curcumin-Containing Inorganic-Based Nanoparticles Intended for In Vivo Cancer Therapy

Curcumin is a natural compound that has been widely investigated thanks to its various biological properties, including antiproliferative. This molecule acts on different cancers such as lung, breast, pancreatic, colorectal, etc. However, the bioactive actions of curcumin have limitations when its physicochemical properties compromise its pharmacological potential. As a therapeutic strategy against cancer, curcumin has been associated with inorganic nanoparticles. These nanocarriers are capable of delivering curcumin and offering physicochemical properties that synergistically enhance anticancer properties. This review highlights the different types of curcumin-based inorganic nanoparticles and discusses their physicochemical properties and in vivo anticancer activity in different models of cancer.

Dendrosomal Curcumin Showed Cytotoxic Effects on Breast Cancer Cell Line by Inducing Mitochondrial Apoptosis Pathway and Cell Division Arrest

Background

Mutations in the p53 gene have been linked to the initiation and progression of breast cancer, as well as resistance to chemotherapy. Therefore, the development of novel treatment approaches is essential to combat this disease.

Objectives

This study aimed to evaluate the effects of dendrosomal curcumin (DNC) on the breast cancer cell line MDA-MB231.

Methods

MDA-MB231 cells were treated with 20 μM DNC, and the apoptosis rate and cell proliferation cycles were assessed using flow cytometry. Additionally, after RNA extraction and cDNA synthesis, the expression levels of Lnc-DANCR, EZH2, Noxa, bcl-2, bax, PUMA, p21, and p53 genes were analyzed using RT-PCR. Protein expression levels of P53, P21, Bcl-2, and Bax were evaluated through western blotting.

Results

Dendrosomal curcumin induced apoptosis in MDA-MB231 cells and caused cell cycle arrest at the SubG1 phase. Dendrosomal curcumin treatment downregulated Lnc-DANCR, EZH2, bcl-2, and p53 gene expression, while upregulating bax, Noxa, PUMA, and p21 gene expression in a time-dependent manner. Bax and P21 protein levels were significantly upregulated following DNC treatment, whereas Bcl-2 and P53 protein levels were downregulated in DNC-treated breast cancer cells.

Conclusions

In summary, dendrosomal nanocurcumin demonstrated potent anti-tumor effects against breast cancer cells, suggesting its potential as a therapeutic agent in breast cancer treatment.

Nano-based formulations of curcumin: elucidating the potential benefits and future prospects in skin cancer

Skin cancer refers to any malignant lesions that occur in the skin and are observed predominantly in populations of European descent. Conventional treatment modalities such as excision biopsy, chemotherapy, radiotherapy, immunotherapy, electrodesiccation, and photodynamic therapy (PDT) induce several unintended side effects which affect a patient's quality of life and physical well-being. Therefore, spice-derived nutraceuticals like curcumin, which are well tolerated, less expensive, and relatively safe, have been considered a promising agent for skin cancer treatment. Curcumin, a chemical constituent extracted from the Indian spice, turmeric, and its analogues has been used in various mammalian cancers including skin cancer. Curcumin has anti-neoplastic activity by triggering the process of apoptosis and preventing the multiplication and infiltration of the cancer cells by inhibiting some signaling pathways and thus subsequently preventing the process of carcinogenesis. Curcumin is also a photosensitizer and has been used in PDT. The major limitations associated with curcumin are poor bioavailability, instability, limited permeation into the skin, and lack of solubility in water. This will constrain the use of curcumin in clinical settings. Hence, developing a proper formulation that can ideally release curcumin to its targeted site is important. So, several nanoformulations based on curcumin have been established such as nanogels, nanoemulsions, nanofibers, nanopatterned films, nanoliposomes and nanoniosomes, nanodisks, and cyclodextrins. The present review mainly focuses on curcumin and its analogues as therapeutic agents for treating different types of skin cancers. The significance of using various nanoformulations as well non-nanoformulations loaded with curcumin as an effective treatment modality for skin cancer is also emphasized.

Advances in the treatment of pancreatic cancer with traditional Chinese medicine

Pancreatic cancer is a common malignancy of the digestive system. With a high degree of malignancy and poor prognosis, it is called the "king of cancers." Currently, Western medicine treats pancreatic cancer mainly by surgical resection, radiotherapy, and chemotherapy. However, the curative effect is not satisfactory. The application of Traditional Chinese Medicine (TCM) in the treatment of pancreatic cancer has many advantages and is becoming an important facet of comprehensive clinical treatment. In this paper, we review current therapeutic approaches for pancreatic cancer. We also review the protective effects shown by TCM in different models and discuss the potential molecular mechanisms of these.

Curcumin induces apoptosis in human hepatocellular carcinoma cells by decreasing the expression of STAT3/VEGF/HIF-1α signaling

Curcumin is the most abundant derivative of turmeric rhizome. Although studies have proved that curcumin could inhibit the growth of tumors, its specific molecular mechanism has not yet been fully elucidated. This study aims to systematically elaborate the mechanisms of curcumin against hepatocellular carcinoma. The anti-tumor effect of curcumin was determined by the cell viability test. Flow cytometry was applied to examine the cell cycle and the apoptosis of cancer cells, and the cancer cell migration was detected by wound healing experiments. The expressions of signal transducers and activators of transcription 3 (STAT3), vascular endothelial growth factor (VEGF), and hypoxia-inducible factor-1α (HIF-1α) in cancer cells were examined by immunostaining and analyzed by the Image J analysis system. After treatment with curcumin, the apoptosis ratio of HepG2 cells increased significantly (P < 0.05). The proliferation of cancer cells was arrested at the S-phase cell cycle, and the migration of cancer cells was inhibited by the increasing concentration of curcumin, together with the decreasing expressions of STAT3, VEGF, and HIF-1α signaling pathways. The results indicate that curcumin could effectively inhibit the growth and migration of hepatocarcinoma cells by inducing cancer cell apoptosis, blocking the cancer cell cycle in the S phase, and reducing the expression of STAT3, VEGF, and HIF-1α signaling pathways.

Autophagic mechanisms in longevity intervention: role of natural active compounds

The term 'autophagy' literally translates to 'self-eating' and alterations to autophagy have been identified as one of the several molecular changes that occur with aging in a variety of species. Autophagy and aging, have a complicated and multifaceted relationship that has recently come to light thanks to breakthroughs in our understanding of the various substrates of autophagy on tissue homoeostasis. Several studies have been conducted to reveal the relationship between autophagy and age-related diseases. The present review looks at a few new aspects of autophagy and speculates on how they might be connected to both aging and the onset and progression of disease. Additionally, we go over the most recent preclinical data supporting the use of autophagy modulators as age-related illnesses including cancer, cardiovascular and neurodegenerative diseases, and metabolic dysfunction. It is crucial to discover important targets in the autophagy pathway in order to create innovative therapies that effectively target autophagy. Natural products have pharmacological properties that can be therapeutically advantageous for the treatment of several diseases and they also serve as valuable sources of inspiration for the development of possible new small-molecule drugs. Indeed, recent scientific studies have shown that several natural products including alkaloids, terpenoids, steroids, and phenolics, have the ability to alter a number of important autophagic signalling pathways and exert therapeutic effects, thus, a wide range of potential targets in various stages of autophagy have been discovered. In this review, we summarised the naturally occurring active compounds that may control the autophagic signalling pathways.

Trilateral association of autophagy, mTOR and Alzheimer's disease: Potential pathway in the development for Alzheimer's disease therapy

The primary and considerable weakening event affecting elderly individuals is age-dependent cognitive decline and dementia. Alzheimer's disease (AD) is the chief cause of progressive dementia, and it is characterized by irreparable loss of cognitive abilities, forming senile plaques having Amyloid Beta (Aβ) aggregates and neurofibrillary tangles with considerable amounts of tau in affected hippocampus and cortex regions of human brains. AD affects millions of people worldwide, and the count is showing an increasing trend. Therefore, it is crucial to understand the underlying mechanisms at molecular levels to generate novel insights into the pathogenesis of AD and other cognitive deficits. A growing body of evidence elicits the regulatory relationship between the mammalian target of rapamycin (mTOR) signaling pathway and AD. In addition, the role of autophagy, a systematic degradation, and recycling of cellular components like accumulated proteins and damaged organelles in AD, is also pivotal. The present review describes different mechanisms and signaling regulations highlighting the trilateral association of autophagy, the mTOR pathway, and AD with a description of inhibiting drugs/molecules of mTOR, a strategic target in AD. Downregulation of mTOR signaling triggers autophagy activation, degrading the misfolded proteins and preventing the further accumulation of misfolded proteins that inhibit the progression of AD. Other target mechanisms such as autophagosome maturation, and autophagy-lysosomal pathway, may initiate a faulty autophagy process resulting in senile plaques due to defective lysosomal acidification and alteration in lysosomal pH. Hence, the strong link between mTOR and autophagy can be explored further as a potential mechanism for AD therapy.

New Visions on Natural Products and Cancer Therapy: Autophagy and Related Regulatory Pathways

Macroautophagy (autophagy) has been a highly conserved process throughout evolution and allows cells to degrade aggregated/misfolded proteins, dysfunctional or superfluous organelles and damaged macromolecules, in order to recycle them for biosynthetic and/or energetic purposes to preserve cellular homeostasis and health. Changes in autophagy are indeed correlated with several pathological disorders such as neurodegenerative and cardiovascular diseases, infections, cancer and inflammatory diseases. Conversely, autophagy controls both apoptosis and the unfolded protein response (UPR) in the cells. Therefore, any changes in the autophagy pathway will affect both the UPR and apoptosis. Recent evidence has shown that several natural products can modulate (induce or inhibit) the autophagy pathway. Natural products may target different regulatory components of the autophagy pathway, including specific kinases or phosphatases. In this review, we evaluated ~100 natural compounds and plant species and their impact on different types of cancers via the autophagy pathway. We also discuss the impact of these compounds on the UPR and apoptosis via the autophagy pathway. A multitude of preclinical findings have shown the function of botanicals in regulating cell autophagy and its potential impact on cancer therapy; however, the number of related clinical trials to date remains low. In this regard, further pre-clinical and clinical studies are warranted to better clarify the utility of natural compounds and their modulatory effects on autophagy, as fine-tuning of autophagy could be translated into therapeutic applications for several cancers.

Targeting autophagy in pancreatic cancer: The cancer stem cell perspective

Pancreatic cancer is currently the seventh leading cause of cancer-related deaths worldwide, with the estimated death toll approaching half a million annually. Pancreatic ductal adenocarcinoma (PDAC) is the most common (>90% of cases) and most aggressive form of pancreatic cancer, with extremely poor prognosis and very low survival rates. PDAC is initiated by genetic alterations, usually in the oncogene KRAS and tumor suppressors CDKN2A, TP53 and SMAD4, which in turn affect a number of downstream signaling pathways that regulate important cellular processes. One of the processes critically altered is autophagy, the mechanism by which cells clear away and recycle impaired or dysfunctional organelles, protein aggregates and other unwanted components, in order to achieve homeostasis. Autophagy plays conflicting roles in PDAC and has been shown to act both as a positive effector, promoting the survival of pancreatic tumor-initiating cells, and as a negative effector, increasing cytotoxicity in uncontrollably expanding cells. Recent findings have highlighted the importance of cancer stem cells in PDAC initiation, progression and metastasis. Pancreatic cancer stem cells (PaCSCs) comprise a small subpopulation of the pancreatic tumor, characterized by cellular plasticity and the ability to self-renew, and autophagy has been recognised as a key process in PaCSC maintenance and function, simultaneously suggesting new strategies to achieve their selective elimination. In this review we evaluate recent literature that links autophagy with PaCSCs and PDAC, focusing our discussion on the therapeutic implications of pharmacologically targeting autophagy in PaCSCs, as a means to treat PDAC.

Identification of a Novel Curcumin Derivative Influencing Notch Pathway and DNA Damage as a Potential Therapeutic Agent in T-ALL

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological malignancy considered curable by modern clinical management. Nevertheless, the prognosis for T-ALL high-risk cases or patients with relapsed and refractory disease is still dismal. Therefore, there is a keen interest in developing more efficient and less toxic therapeutic approaches. T-ALL pathogenesis is associated with Notch signaling alterations, making this pathway a highly promising target in the fight against T-ALL. Here, by exploring the anti-leukemic capacity of the natural polyphenol curcumin and its derivatives, we found that curcumin exposure impacts T-ALL cell line viability and decreases Notch signaling in a dose- and time-dependent fashion. However, our findings indicated that curcumin-mediated cell outcomes did not depend exclusively on Notch signaling inhibition, but might be mainly related to compound-induced DNA-damage-associated cell death. Furthermore, we identified a novel curcumin-based compound named CD2066, endowed with potentiated anti-proliferative activity in T-ALL compared to the parent molecule curcumin. At nanomolar concentrations, CD2066 antagonized Notch signaling, favored DNA damage, and acted synergistically with the CDK1 inhibitor Ro3306 in T-ALL cells, thus representing a promising novel candidate for developing therapeutic agents against Notch-dependent T-ALL.

Autophagy: A Key Player in Pancreatic Cancer Progression and a Potential Drug Target

Pancreatic cancer is known to have the lowest survival outcomes among all major cancers, and unfortunately, this has only been marginally improved over last four decades. The innate characteristics of pancreatic cancer include an aggressive and fast-growing nature from powerful driver mutations, a highly defensive tumor microenvironment and the upregulation of advantageous survival pathways such as autophagy. Autophagy involves targeted degradation of proteins and organelles to provide a secondary source of cellular supplies to maintain cell growth. Elevated autophagic activity in pancreatic cancer is recognized as a major survival pathway as it provides a plethora of support for tumors by supplying vital resources, maintaining tumour survival under the stressful microenvironment and promoting other pathways involved in tumour progression and metastasis. The combination of these features is unique to pancreatic cancer and present significant resistance to chemotherapeutic strategies, thus, indicating a need for further investigation into therapies targeting this crucial pathway. This review will outline the autophagy pathway and its regulation, in addition to the genetic landscape and tumor microenvironment that contribute to pancreatic cancer severity. Moreover, this review will also discuss the mechanisms of novel therapeutic strategies that inhibit autophagy and how they could be used to suppress tumor progression.

Curcumin enhances p-cresyl sulfate-induced cytotoxic effects on renal tubular cells

Indoxyl sulfate (IS) and p-cresyl sulfate (PCS), protein-bound uremic toxins, can induce oxidative stress and cause renal disease progression. However, the different cytotoxic effects on renal cells between IS and PCS are not stated. Due to uremic toxins are generally found in CKD patients, the mechanisms of uremic toxins-induced renal injury are required to study. Curcumin has anti-oxidant, anti-inflammatory and anti-apoptotic effects which may be potential used to protect against renal damage. In contrast, curcumin also exert cytotoxic effects on various cells. In addition, curcumin may reduce or enhance cytotoxicity combined with different chemicals treatments. However, whether curcumin may influence uremic toxins-induced renal injury is unclear. The goal of this study is to compare the different cytotoxic effects on renal cells between IS and PCS treatment, as well as the synergistic or antagonistic effects by combination treatments with curcumin and PCS. Our experimental result shows the PCS exerts a stronger antiproliferative effect on renal tubular cells than IS treatment. In addition, our study firstly demonstrates that curcumin enhances PCS-induced cell cytotoxicity through caspase-dependent apoptotic pathway and cell cycle alteration.

Geraniin inhibits cell growth and promoted autophagy-mediated cell death in the nasopharyngeal cancer C666-1 cells

Background

Nasopharyngeal carcinoma (NPC) is a rare malignant tumor developing from epithelial linings of nasopharynx, and 10–50 out of 100,000 NPC cases were recorded globally particularly in the Asian countries.

Methodology

The cytotoxicity of geraniin against the NPC C666-1 cells were analyzed using MTT assay. The influences of geraniin on the C666-1 cell viability with the presence of ROS and apoptosis inhibitors were also studied. The expressions of PI3K, Akt, mTOR, and autophagic markers LC3, ATG7, P62/SQSTM1 expressions in the C666-1 cells were studied by western blotting analysis. The ROS production was assayed using DCFH-DA staining. The immunofluorescence assay was performed to detect the NF-κB and β-catenin expressions in the C666-1 cells.

Results

The cell viability of C666-1 cells were appreciably prevented by the geraniin. The geraniin treatment also inhibited the C666-1 cell growth with the presence of apoptotic inhibitor Z-VAD-FMK. The geraniin-treatment effectively improved the ROS production and inhibited the NF-κB and β-catenin expressions in the C666-1 cells. Geraniin appreciably modulated the PI3K/Akt/mTOR signaling axis and improved the autophagy-mediated cell death via improving the autophagic markers LC3 and ATG7 expressions in the C666-1 cells.

Conclusion

In conclusion, our results proved that geraniin inhibits C666-1 cell growth and initiated autophagy-mediated cell death via modulating PI3K/Akt/mTOR cascade and improving LC3 and ATG7 expressions in the C666-1. Geraniin and it could be a hopeful and efficient candidate to treat the human NPC in the future.

Molecular Targets of Natural Compounds with Anti-Cancer Properties

Cancer is the second leading cause of death in humans. Despite rapid developments in diagnostic methods and therapies, metastasis and resistance to administrated drugs are the main obstacles to successful treatment. Therefore, the main challenge should be the diagnosis and design of optimal therapeutic strategies for patients to increase their chances of responding positively to treatment and increase their life expectancy. In many types of cancer, a deregulation of multiple pathways has been found. This includes disturbances in cellular metabolism, cell cycle, apoptosis, angiogenesis, or epigenetic modifications. Additionally, signals received from the microenvironment may significantly contribute to cancer development. Chemical agents obtained from natural sources seem to be very attractive alternatives to synthetic compounds. They can exhibit similar anti-cancer potential, usually with reduced side effects. It was reported that natural compounds obtained from fruits and vegetables, e.g., polyphenols, flavonoids, stilbenes, carotenoids and acetogenins, might be effective against cancer cells in vitro and in vivo. Several published results indicate the activity of natural compounds on protein expression by its influence on transcription factors. They could also be involved in alterations in cellular response, cell signaling and epigenetic modifications. Such natural components could be used in our diet for anti-cancer protection. In this review, the activities of natural compounds, including anti-cancer properties, are described. The influence of natural agents on cancer cell metabolism, proliferation, signal transduction and epigenetic modifications is highlighted.

Curcumin induces apoptosis and autophagy inhuman renal cell carcinoma cells via Akt/mTOR suppression

Renal cell carcinoma (RCC) is a highly aggressive cancer leading to high economic and social burden, and has increasing annual cases. Curcumin is a traditional Chinese medicine widely used as anti-inflammatory, anti-viral and anti-cancer agent, thus can be applicable in RCC therapy. The work assessed the effects of RCC treatment with Curcumin, Curcumin+3-MA, Curcumin+ CQ or curcumin+ Z-VAD in vitro and in vivo, and the mechanisms involved in inhibition of tumor cells proliferation. The study used ACHN tumor cells and C57BL/6 nude mice for results validation. Cell proliferation was determined through MTT assays while apoptosis was investigated using Annexin V-FITC/PI kit and flow cytometry. Enzyme-linked immunosorbent assay (ELISA) was used to detect IL-6, IL-8, and TNF-α cytokines expressions. AKT/mTOR and autophagy proteins expressions were investigated through western blot and immunofluorescence. The results indicated significantly inhibited cell viability following ACHN tumor cells treatments with curcumin alone, or with the various combinations, as compared to the control. Apoptosis was significantly increased following curcumin treatment, but was significantly reversed after treatment with curcumin+ 3-MA. Likewise, AKT/mTOR proteins expression were significantly reduced while the autophagy-related proteins were significantly elevated following curcumin treatment. The tumor size, weight and volumes were also significantly suppressed following treatment with curcumin. In conclusion, the investigation demonstrated that curcumin suppressed ACHN cell viability, induced apoptosis and autophagy, through the suppression of AKT/mTOR pathway. Use of curcumin to target AKT/mTOR pathway could be an effective treatment alternative for renal cell carcinoma.

Synergistic action of curcumin and cisplatin on spinel ferrite/hierarchical MCM-41 nanocomposite against MCF-7, HeLa and HCT 116 cancer cell line

Background

Platinum-based drugs are widely used in cancer therapy, but are known for toxic side effects and resistance. Combinational drug delivery represents an effective chemotherapeutic strategy, but often leads to an increased toxicity. Aim of this study is to test the co-delivery of cisplatin with natural antioxidants on hierarchial porous large surface area hexagonal nanocarriers for synergistic action.

Results

A series of structured mesoporous materials were impregnated with magnetic spinel ferrite (30% CuFe2O4) and then coated with curcumin (25% wt/wt). Mesosilicalite and MCM-41 with high curcumin release abilities were functionalized with cisplatin (5% wt/wt) for synergistic effect of combinational drugs. The cytotoxic efficiency of our nanocomposites was tested on cell viability of MCF7 (human breast cancer), human cervical cancer (HeLa), colorectal cancer (HCT116), and HFF (human foreskin fibroblasts) cell lines using the MTT cell viability assay. At a concentration of 0.1 mg/ml, CuFe2O4/mesosilicalite/curcumin/cisplatin resulted in 89.53% reduction in viability in MCF7, 94.03% in HeLa, 64% in HCT116 and 87% in HFF; whereas, CuFe2O4/MCM-41/curcumin/cisplatin resulted in 76% reduction in viability in MCF7, 64.46% in HeLa, 64% in HCT116 and 24% in HFF. The EC50 for CuFe2O4/mesosilicalite/curcumin/cisplatin was 81.23 µg/ml in MCF7, 47.55 µg/ml in HeLa, 48.96 µg/ml in HCT116 and 76.83 µg/ml in HFF. The EC50 for CuFe2O4/MCM-41/curcumin/cisplatin was 72.51 µg/ml in MCF7, 58.6 µg/ml in HeLa, 62.58 µg/ml in HCT116 and 154.2 µg/ml in HFF. Furthermore, cells treated with both nanocomposites had a high number of cleaved Caspase 3-positive cells suggesting that the reduction in cell viability was triggered by activating the apoptotic signaling pathway.

Conclusion

Our results show that CuFe2O4/MCM-41/curcumin/cisplatin is a better candidate for combinational drug therapy due to its lowest EC50 value and the wider difference in EC50 (a fold change) between cancerous and non-cancerous cell line.

Curcumol simultaneously induces both apoptosis and autophagy in human nasopharyngeal carcinoma cells

Autophagy is usually considered as a protective mechanism against cell death, and in the meantime, leads to cell injury even apoptosis. Apoptosis and autophagy are very closely connected and may cooperate, coexist, or antagonize each other on progressive occurrence of cell death triggered by natural compounds. Therefore, the interplay between the two modes of death is essential for the overall fate of cancer cells. Our previous study revealed that curcumol induced apoptosis in nasopharyngeal carcinoma (NPC) cells. Recently, curcumol was found to induce autophagy in cancer cells. However, whether curcumol can induce NPC cells autophagy and the effects of autophagy on apoptosis remain elusive. In this study, we found that curcumol induced autophagy through AMPK/mTOR pathway in CNE-2 cells. Moreover, inhibiting autophagy by autophagy inhibitor 3-methyladenine (3-MA) or apoptosis inhibitor z-VAD-fmk significantly increased proliferation while attenuated apoptosis and autophagy compared with the curcumol 212 μM group. In contrast, combining curcumol with autophagy agonist rapamycin and apoptosis inducer MG132 synergized the apoptotic and autophagic effect of curcumol. Taken together, our study demonstrates that curcumol promotes autophagy in NPC via AMPK/mTOR pathway, induces autophagy enhances the activity of curcumol in NPC cells; the combination of autophagy inducer and curcumol can be a new therapeutic strategy for NPC.

Cellular uptake and apoptotic properties of gemini curcumin in gastric cancer cells

INTRODUCTION

Curcumin is a polyphenolic natural compound, which has demonstrated to possess antioxidant, anti-inflammatory, and anticancer effects in vitro & in vivo. However, its applicability in cancer therapy has been limited due to its poor cellular uptake. Here, we aimed to evaluate the anticancer effect of novel gemini curcumin (Gemini-Cur) on the gastric cancer AGS cells.

METHOD

The AGS cancerous and HFF-2 non-cancerous cells were treated with Gemini-Cur and curcumin (Cur) in a time- and dose-dependent manner. Cellular toxicity was studied using MTT, fluorescence microscopy, annexin V/FITC, and cell cycle assays. Additionally, real-time PCR and western blotting were employed to evaluate the expression of Bax, Bcl-2 and survivin genes.

RESULTS

Our data indicated that Gemini-Cur is significantly taken into AGS cells compared to Cur. Moreover, the viability of Gemini-Cur treated cells was significantly reduced in a time- and dose-dependent manner (p < 0.001). Gemini-Cur compound induced G2/M cell cycle arrest that was followed by apoptosis in a time-dependent manner (p < 0.0001).

DISCUSSION

Taken together, our findings support the idea that Gemini-Cur has the potential to be considered as an anticancer agent.

Cancer Therapy Challenge: It Is Time to Look in the "St. Patrick's Well" of the Nature

Cancer still remains a leading cause of death despite improvements in diagnosis, drug discovery and therapy approach. Therefore, there is a strong need to improve methodologies as well as to increase the number of approaches available. Natural compounds of different origins (i.e., from fungi, plants, microbes, etc.) represent an interesting approach for fighting cancer. In particular, synergistic strategies may represent an intriguing approach, combining natural compounds with classic chemotherapeutic drugs to increase therapeutic efficacy and lower the required drug concentrations. In this review, we focus primarily on those natural compounds utilized in synergistic approached to treating cancer, with particular attention to those compounds that have gained the most research interest.

Chrysosplenol D Triggers Apoptosis through Heme Oxygenase-1 and Mitogen-Activated Protein Kinase Signaling in Oral Squamous Cell Carcinoma

Simple Summary

Oral squamous cell carcinoma (OSCC) accounts for the most malignancies. A GLO-BOCAN 2020 report estimated 377,713 new cases of oral cancer and 177,757 deaths due to oral cancer in 2020. Chrysosplenol D, a flavonol isolated from Artemisia annua L., can exert an-ticancer effects. This study investigated the anticancer property of chrysosplenol D and its un-derlying mechanism in oral squamous cell carcinoma. We observed that chrysosplenol D reduced cell viability, cell cycle arrest, apoptosis and autophagy in OSCC. Moreover, the upregulation of heme oxygenase-1 (HO-1) was found to be critical for chrysosplenol D-induced apoptotic cell death that patients with head and neck cancer had lower HO-1 expression. The findings of the present study indicated that chrysosplenol D exerts anticancer effects on OSCC by suppressing the MAPK pathway and activating HO-1 expression. Suggest that chrysosplenol D might be a potential anticancer agent for treating OSCC.

Abstract

Chrysosplenol D, a flavonol isolated from Artemisia annua L., can exert anticancer effects. This study investigated the anticancer property of chrysosplenol D and its underlying mechanism in oral squamous cell carcinoma (OSCC). We observed that chrysosplenol D reduced cell viability and caused cell cycle arrest in the G₂/M phase. The findings of annexin V/propidium iodide staining, chromatin condensation, and apoptotic-related protein expression revealed that chrysosplenol D regulated apoptosis in OSCC. Furthermore, chrysosplenol D altered the expression of the autophagy marker LC3 and other autophagy-related proteins. Phosphatidylinositol 3-kinase/protein kinase B, extracellular signal-regulated kinase, c-Jun N-terminal kinase, and p38 mitogen-activated protein kinase (MAPK) were downregulated by chrysosplenol D, and the inhibition of these pathways significantly enhanced chrysosplenol D-induced cleaved poly (ADP-ribose) polymerase activation. Moreover, the upregulation of heme oxygenase-1 (HO-1) was found to be critical for chrysosplenol D-induced apoptotic cell death. The analysis of clinical data from The Cancer Genome Atlas and Gene Expression Omnibus datasets revealed that patients with head and neck cancer had lower HO-1 expression than did those with no head and neck cancer. The findings of the present study indicated that chrysosplenol D exerts anticancer effects on OSCC by suppressing the MAPK pathway and activating HO-1 expression.

Therapeutic effect of curcumin in gastrointestinal cancers: A comprehensive review

Gastrointestinal (GI) cancers with a high global prevalence are a leading cause of morbidity and mortality. Accordingly, there is a great need to develop efficient therapeutic approaches. Curcumin, a naturally occurring agent, is a promising compound with documented safety and anticancer activities. Recent studies have demonstrated the activity of curcumin in the prevention and treatment of different cancers. According to systematic studies on curcumin use in various diseases, it can be particularly effective in GI cancers because of its high bioavailability in the gastrointestinal tract. Nevertheless, the clinical applications of curcumin are largely limited because of its low solubility and low chemical stability in water. These limitations may be addressed by the use of relevant analogues or novel delivery systems. Herein, we summarize the pharmacological effects of curcumin against GI cancers. Moreover, we highlight the application of curcumin's analogues and novel delivery systems in the treatment of GI cancers.

The Curcumin Analog GO-Y030 Controls the Generation and Stability of Regulatory T Cells

Regulatory T cells (Tregs) play a crucial role in preventing antitumor immune responses in cancer tissues. Cancer tissues produce large amounts of transforming growth factor beta (TGF-β), which promotes the generation of Foxp3+ Tregs from naïve CD4+ T cells in the local tumor microenvironment. TGF-β activates nuclear factor kappa B (NF-κB)/p300 and SMAD signaling, which increases the number of acetylated histones at the Foxp3 locus and induces Foxp3 gene expression. TGF-β also helps stabilize Foxp3 expression. The curcumin analog and antitumor agent, GO-Y030, prevented the TGF-β-induced generation of Tregs by preventing p300 from accelerating NF-κB-induced Foxp3 expression. Moreover, the addition of GO-Y030 resulted in a significant reduction in the number of acetylated histones at the Foxp3 promoter and at the conserved noncoding sequence 1 regions that are generated in response to TGF-β. In vivo tumor models demonstrated that GO-Y030-treatment prevented tumor growth and reduced the Foxp3+ Tregs population in tumor-infiltrating lymphocytes. Therefore, GO-Y030 exerts a potent anticancer effect by controlling Treg generation and stability.

Potential Therapeutic Targets of Curcumin, Most Abundant Active Compound of Turmeric Spice: Role in the Management of Various Types of Cancer

BACKGROUND

Curcumin, an active compound of turmeric spice, is one of the most-studied natural compounds and has been widely recognized as a chemopreventive agent. Several molecular mechanisms have proven that curcumin and its analogs play a role in cancer prevention through modulating various cell signaling pathways as well as in the inhibition of the carcinogenesis process.

OBJECTIVE

To study the potential role of curcumin in the management of various types of cancer through modulating cell signalling molecules based on available literature and recent patents.

METHODS

A wide-ranging literature survey was performed based on Scopus, PubMed, PubMed Central, and Google scholar for the implication of curcumin in cancer management, along with a special emphasis on human clinical trials. Moreover, patents were searched through www.google.com/patents, www.freepatentsonline.com, and www.freshpatents.com.

RESULT

Recent studies based on cancer cells have proven that curcumin has potential effects against cancer cells as it prevents the growth of cancer and acts as a cancer therapeutic agent. Besides, curcumin exerted anti-cancer effects by inducing apoptosis, activating tumor suppressor genes, cell cycle arrest, inhibiting tumor angiogenesis, initiation, promotion, and progression stages of tumor. It was established that co-treatment of curcumin and anti-cancer drugs could induce apoptosis and also play a significant role in the suppression of the invasion and metastasis of cancer cells.

CONCLUSION

Accumulating evidences suggest that curcumin has the potential to inhibit cancer growth, induce apoptosis, and modulate various cell signaling pathway molecules. Well-designed clinical trials of curcumin based on human subjects are still needed to establish the bioavailability, mechanism of action, efficacy, and safe dose in the management of various cancers.

c-Jun NH2-terminal kinase (JNK)/stress-activated protein kinase-associated protein 1 (JSAP1) attenuates curcumin-induced cell death differently from its family member, JNK-associated leucine zipper protein (JLP)

Curcumin, a major component of turmeric, is known to exhibit multiple biological functions including antitumor activity. We previously reported that the mitogen-activated protein kinase (MAPK) scaffold protein c-Jun NH₂-terminal kinase (JNK)-associated leucine zipper protein (JLP) reduces curcumin-induced cell death by modulating p38 MAPK and autophagy through the regulation of lysosome positioning. In this study, we investigated the role of JNK/stress-activated protein kinase-associated protein 1 (JSAP1), a JLP family member, in curcumin-induced stress, and found that JSAP1 also attenuates curcumin-induced cell death. However, JSAP1 knockout showed no or little effect on the activation of JNK and p38 MAPKs in response to curcumin. In addition, small molecule inhibitors of JNK and p38 MAPKs did not increase curcumin-induced cell death. Furthermore, JSAP1 depletion did not impair lysosome positioning and autophagosome-lysosome fusion. Instead, we noticed substantial autolysosome accumulation accompanied by an inefficient autophagic flux in JSAP1 knockout cells. Taken together, these results indicate that JSAP1 is involved in curcumin-induced cell death differently from JLP, and may suggest that JSAP1 plays a role in autophagosome degradation and its dysfunction results in enhanced cell death. The findings of this study may contribute to the development of novel therapeutic approaches using curcumin for cancer.

Potential protective roles of curcumin against cadmium-induced toxicity and oxidative stress

Curcumin, used as a spice and traditional medicine in India, exerts beneficial effects against several diseases, owing to its antioxidant, analgesic, and anti-inflammatory properties. Evidence indicates that curcumin might protect against heavy metal-induced organ toxicity by targeting biological pathways involved in anti-oxidation, anti-inflammation, and anti-tumorigenesis. Curcumin has received considerable attention owing to its therapeutic properties, and the mechanisms underlying some of its actions have been recently investigated. Cadmium (Cd) is a heavy metal found in the environment and used extensively in industries. Chronic Cd exposure induces damage to bones, liver, kidneys, lungs, testes, and the immune and cardiovascular systems. Because of its long half-life, exposure to even low Cd levels might be harmful. Cd-induced toxicity involves the overproduction of reactive oxygen species (ROS), resulting in oxidative stress and damage to essential biomolecules. Dietary antioxidants, such as chelating agents, display the potential to reduce Cd accumulation and metal-induced toxicity. Curcumin scavenges ROS and inhibits oxidative damage, thus resulting in many therapeutic properties. This review aims to address the effectiveness of curcumin against Cd-induced organ toxicity and presents evidence supporting the use of curcumin as a protective antioxidant.

A Curcumin Analog Reduces Levels of the Alzheimer's Disease-Associated Amyloid-β Protein by Modulating AβPP Processing and Autophagy

Alzheimer's disease (AD) is a devastating neurodegenerative disease with no cure currently available. A pathological hallmark of AD is accumulation and deposition of amyloid-β protein (Aβ), a ∼4 kDa peptide generated through serial cleavage of the amyloid-β protein precursor (AβPP) by β- and γ-secretases. Curcumin is a natural compound primarily found in the widely used culinary spice, turmeric, which displays therapeutic potential for AD. Recently, we reported the development of curcumin analogs and identified a lead compound, curcumin-like compound-R17 (CLC-R17), that significantly attenuates Aβ deposition in an AD transgenic mouse model. Here, we elucidated the mechanisms of this analog on Aβ levels and AβPP processing using cell models of AD. Using biochemical methods and our recently developed nanoplasmonic fiber tip probe technology, we showed that the lead compound potently lowers Aβ levels in conditioned media and reduces oligomeric amyloid levels in the cells. Furthermore, like curcumin, the lead compound attenuates the maturation of AβPP in the secretory pathway. Interestingly, it upregulated α-secretase processing of AβPP and inhibited β-secretase processing of AβPP by decreasing BACE1 protein levels. Collectively, our data reveal mechanisms of a promising curcumin analog in reducing Aβ levels, which strongly support its development as a potential therapeutic for AD.

Traditional Chinese medicine may be further explored as candidate drugs for pancreatic cancer: A review

Pancreatic cancer is a disease with a high mortality rate. Although survival rates for different types of cancers have improved in recent years, the five-year survival rate of pancreatic cancer stands at 8%. Moreover, the current first-line therapy, gemcitabine, results in low remission rates and is associated with drug resistance problems. Alternative treatments for pancreatic cancer such as surgery, chemotherapy and radiation therapy provide marginal remission and survival rates. This calls for the search of more effective drugs or treatments. Traditional Chinese medicine contains numerous bioactive ingredients some of which show activity against pancreatic cancer. In this review, we summarize the mechanisms of five types of traditional Chinese medicine monomers. In so-doing, we provide new potential drug candidates for the treatment of pancreatic cancer.

Turmeric and Its Major Compound Curcumin on Health: Bioactive Effects and Safety Profiles for Food, Pharmaceutical, Biotechnological and Medicinal Applications

Curcumin, a yellow polyphenolic pigment from the Curcuma longa L. (turmeric) rhizome, has been used for centuries for culinary and food coloring purposes, and as an ingredient for various medicinal preparations, widely used in Ayurveda and Chinese medicine. In recent decades, their biological activities have been extensively studied. Thus, this review aims to offer an in-depth discussion of curcumin applications for food and biotechnological industries, and on health promotion and disease prevention, with particular emphasis on its antioxidant, anti-inflammatory, neuroprotective, anticancer, hepatoprotective, and cardioprotective effects. Bioavailability, bioefficacy and safety features, side effects, and quality parameters of curcumin are also addressed. Finally, curcumin's multidimensional applications, food attractiveness optimization, agro-industrial procedures to offset its instability and low bioavailability, health concerns, and upcoming strategies for clinical application are also covered.

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.

Biochemistry, Safety, Pharmacological Activities, and Clinical Applications of Turmeric: A Mechanistic Review

Turmeric (Curcuma longa L.) is a popular natural drug, traditionally used for the treatment of a wide range of diseases. Its root, as its most popular part used for medicinal purposes, contains different types of phytochemicals and minerals. This review summarizes what is currently known on biochemistry, safety, pharmacological activities (mechanistically), and clinical applications of turmeric. In short, curcumin is considered as the fundamental constituent in ground turmeric rhizome. Turmeric possesses several biological activities including anti-inflammatory, antioxidant, anticancer, antimutagenic, antimicrobial, antiobesity, hypolipidemic, cardioprotective, and neuroprotective effects. These reported pharmacologic activities make turmeric an important option for further clinical research. Also, there is a discussion on its safety and toxicity.

A pH-sensitive delivery system based on N-succinyl chitosan-ZnO nanoparticles for improving antibacterial and anticancer activities of curcumin

Inherent selective cytotoxicity, antibacterial activity and unique physicochemical properties of ZnO nanostructures and chitosan (CS) make them promising candidates for drug delivery. In this study, ZnO nanoparticles functionalized by N-succinyl chitosan as a pH-sensitive delivery system were synthesized to enhance the therapeutic potential of curcumin (CUR). CS coated-ZnO nanoparticles were synthesized by a co-precipitation method in the presence of CS. Chemical modification of CS-ZnO particles was performed by succinic anhydride for introducing -COOH functional groups which were then activated using 1,1'‑carbonyldiimidazole for CUR conjugation. The spherical-like CUR-conjugated system (CUR-CS-ZnO) with the average particle size of 40 nm presented significantly enhanced water dispersibility versus free CUR. The experimental study of CUR release from the system showed a pH-sensitive release profile, which enabled drug delivery to tumors and infection sites. MTT and Annexin-V FITC/PI assays revealed the superior anticancer activity of CUR-CS-ZnO compared to free CUR against breast cancer cells (MDA-MB-231) by inducing the apoptotic response with no cytotoxic effects on HEK293 normal cells. Moreover, CUR conjugation to the system notably dropped the MIC (25 to 50-fold) and MBC values (10 to 40-fold) against S. aureus and E. coli. The features qualify the formulation for anticancer and antimicrobial applications in the future.

Impact of curcumin on replicative and chronological aging in the Saccharomyces cerevisiae yeast

Curcumin is a biologically active compound of vegetable origin which has a hormetic effect. Pro-health and anti-aging properties of curcumin have been known for years. The main benefit of curcumin is thought to be its anti-oxidative action. Despite vast amount of data confirming age-delaying activity of curcumin in various groups of organisms, so far little has been discovered about curcumin's impact on cell aging in the experimental model of the Saccharomyces cerevisiae budding yeast. We have been able to demonstrate that curcumin significantly increases oxidative stress and accelerates replicative and chronological aging of yeast cells devoid of anti-oxidative protection (with SOD1 and SOD2 gene deletion) and deprived of DNA repair mechanisms (RAD52). Interestingly, curcumin delays aging, probably through hormesis, of the wild-type strain BY4741.

Indomethacin and juglone inhibit inflammatory molecules to induce apoptosis in colon cancer cells

Colorectal cancer (CRC) is the third most common fatal cancer. Indomethacin, a nonsteroidal anti-inflammatory drug, is known to reduce the occurrence of CRC. This study evaluated the potential anticolon cancer effects of juglone (5-hydroxy-1,4-naphthoquinone) in combination with indomethacin. Human colon adenocarcinoma cells (HT29) were subjected to treatment with indomethacin, juglone, and a combination of both. Morphological analysis, cell cycle regulation, and dual staining using acridine orange and ethidium bromide in control and treated cells revealed the apoptotic potential of these compounds. Bcl2 and inflammatory molecules (tumor necrosis factor-α, nuclear factor kappa B, and Cox-2) were found to be decreased with a concomitant increase in the expression of proapoptotic molecules (Bad, Bax, cytochrome c, and PUMA) as a result of the molecular regulation of Wnt, Notch, and peroxisome proliferator-activated receptor-γ signaling. Treatment with juglone was not as effective as with indomethacin; however, a combination of both was shown to be more effective, suggesting that juglone may be considered for therapeutic intervention of colon cancer.

Curcumin ameliorates dextran sulfate sodium-induced colitis in mice via regulation of autophagy and intestinal immunity

BACKGROUND/AIMS

Inflammatory bowel disease (IBD) is regarded as a kind of chronic and unspecific intestinal inflammatory disorder. Its exact pathogenesis has not been elucidated. Curcumin, as an herbal drug, has been used in the treatment of IBD due to its immunoregulation. Autophagy has been reported to play an important role in the mechanism of IBD. In the present study, we focused on the autophagic regulation role of curcumin in the murine model of dextran sulfate sodium (DSS)-induced colitis.

MATERIALS AND METHODS

We investigated the effects of curcumin on the progress of DSS-induced acute colitis in mice by evaluating the disease activity index (DAI) and histopathological score. Meanwhile, the mRNA and protein expression of autophagy-related key genes from colon tissues comprising autophagy-related 5 (ATG5), LC3-phosphatidylethanolamine conjugate (LC-3II), beclin-1, and B cell lymphoma 2 (bcl-2) was examined by quantitative reverse transcription polymerase chain reaction and Western blot. Furthermore, the mRNA and protein expression of cytokines, including tumor necrosis factor (TNF)-α, interleukin (IL) 6, IL-10, and IL-17A, was examined. Autophagosome was also examined under transmission electron microscopy.

RESULTS

Both DAI and histopathological score increased in mice with DSS-induced colitis and obviously decreased after curcumin intervention. The expression levels of TNF-α, IL-6, IL-17, ATG5, LC-3II, and beclin-1 were significantly higher in mice with colitis than in normal ones, whereas those of IL-10 and bcl-2 decreased accordingly. However, curcumin intervention adjusted the expression level of those factors toward normal level. The number of autophagosome in the colon epithelia increased after DSS stimulation and decreased after curcumin administration.

CONCLUSION

Curcumin could prevent the development of DSS-induced colitis through the inhibition of excessive autophagy and regulation of following cytokine networks.

Protective role of c-Jun NH2-terminal kinase-associated leucine zipper protein (JLP) in curcumin-induced cancer cell death

Previous studies have established the antitumor activity of curcumin, a major component of turmeric. Increasing evidence indicates that curcumin induces autophagy, the activation of mitogen-activated protein kinase (MAPK) intracellular signaling pathways, and reactive oxygen species (ROS)-mediated cell death. The c-Jun NH₂-terminal kinase (JNK)-associated leucine zipper protein (JLP), a scaffold protein for MAPK signaling pathways, has been identified as a candidate biomarker for cancer. In this study, we explored the role of JLP in curcumin-induced cancer cell death. We found that JLP knockdown (KD) increases cell death and intracellular ROS levels. Furthermore, JLP KD impaired lysosomal accumulation around perinuclear regions, which led to the inhibition of autophagosome-lysosome fusion, and attenuated p38 MAPK activation in curcumin-treated cells. The decreases in cell viability and p38 MAPK activation were reversed by expressing wild-type JLP but not a JLP mutant lacking the p38 MAPK-binding domain. In addition, the inactivation of a key gene involved in autophagy increased sensitivity to curcumin-induced cell death. Together, these results suggest that JLP mediates the induction of autophagy by regulating lysosome positioning and p38 MAPK signaling, indicating an overall protective role in curcumin-induced ROS-mediated cancer cell death.

Curcumin Nicotinate Selectively Induces Cancer Cell Apoptosis and Cycle Arrest through a P53-Mediated Mechanism

Curcumin is an anticancer agent, but adverse effects and low bioavailability are its main drawbacks, which drives efforts in chemical modifications of curcumin. This study evaluated antiproliferative activity and cancer cell selectivity of a curcumin derivative, curcumin nicotinate (CN), in which two niacin molecules were introduced. Our data showed that CN effectively inhibited proliferation and clonogenic growth of colon (HCT116), breast (MCF-7) and nasopharyngeal (CNE2, 5-8F and 6-10B) cancer cells with IC50 at 27.7 μM, 73.4 μM, 64.7 μM, 46.3 μM, and 31.2 μM, respectively. In cancer cells, CN induced apoptosis and cell cycle arrest at G2/M phase through a p53-mediated mechanism, where p53 was activated, p21 and pro-apoptotic proteins Bid and Bak were upregulated, and PARP was cleaved. In non-transformed human mammary epithelial cells MCF10A, CN at 50 µM had no cytotoxicity and p53 was not activated, but curcumin at 12.5 µM activated p53 and p21 and inhibited MCF10A cell growth. These data suggest that CN inhibits cell growth and proliferation through p53-mediated apoptosis and cell cycle arrest with cancer cell selectivity.

A biological extract of turmeric (Curcuma longa) modulates response of cartilage explants to lipopolysaccharide

Background

Turmeric is commonly used as a dietary treatment for inflammation, but few studies have evaluated the direct effect of turmeric on cartilage. The purpose of this study was to characterize cartilage explants’ inflammatory responses to lipopolysaccharide in the presence of a simulated biological extract of turmeric.

Methods

Turmeric was incubated in simulated gastric and intestinal fluid, followed by inclusion of liver microsomes and NADPH. The resulting extract (TUR_sim) was used to condition cartilage explants in the presence or absence of lipopolysaccharide. Explants were cultured for 96 h (h); the first 24 h in basal tissue culture media and the remaining 72 h in basal tissue culture media containing TUR_sim (0, 3, 9 or 15 μg/mL). Lipopolysaccharide (0 or 5 μg/mL) was added for the final 48 H. media samples were collected immediately prior to lipopolysaccharide exposure (0 h) and then at 24 and 48 h after, and analyzed for prostaglandin E₂ (PGE₂), glycosaminoglycan (GAG), and nitric oxide (NO). Explants were stained with calcein-AM for an estimate of live cells. Data were analyzed using a 2-way repeated measures (GAG, PGE₂, NO) or 1-way ANOVA without repeated measures (viability). Significance accepted at p < 0.05.

Results

TUR_sim significantly reduced PGE_2, NO and GAG, and calcein fluorescence was reduced. Conclusions: These data contribute to the growing body of evidence for the utility of turmeric as an intervention for cartilage inflammation.

Curcumin diethyl disuccinate, a prodrug of curcumin, enhances anti-proliferative effect of curcumin against HepG2 cells via apoptosis induction

Curcumin (Cur) has been reported to have anti-hepatocellular carcinoma activity but its poor oral bioavailability limits its further development as a chemotherapeutic agent. We synthesized previously a succinate ester prodrug of Cur, curcumin diethyl disuccinate (CurDD) with better chemical stability in a buffer solution pH 7.4. Here, we further investigated and compared the cellular transport and anti-proliferative activity against HepG2 cells of CurDD and Cur. Transport of CurDD across the Caco-2 monolayers provided a significantly higher amount of the bioavailable fraction (BF) of Cur with better cytotoxicity against HepG2 cells compared to that of Cur (p < 0.05). Flow cytometric analysis showed that the BF of CurDD shifted the cell fate to early and late apoptosis to a higher extent than that of Cur. The Western blot analysis revealed that CurDD increased Bax protein expression, downregulated Bcl-2 protein, activated caspase-3 and -9 and increased LC3-II protein level in HepG2 cells. Flow cytometric and immunoblotting results suggest that CurDD can induce HepG2 cell death via an apoptotic pathway. We suggest that CurDD can overcome the limitations of Cur in terms of cellular transport with a potential for further extensive in vitro and in vivo studies of anti-hepatocellular carcinoma effects.