Current status and future prospective of Curcumin as a potential therapeutic agent in the treatment of colorectal cancer

Curcumin Nanoparticles-related Non-invasive Tumor Therapy, and Cardiotoxicity Relieve

Non-invasive antitumor therapy can treat tumor patients who cannot tolerate surgery or are unsuitable. However, tumor resistance to non-invasive antitumor therapy and cardiotoxicity caused by treatment seriously affect the quality of life and prognosis of patients. As a kind of polyphenol extracted from herbs, curcumin has many pharmacological effects, such as anti-inflammation, antioxidation, antitumor, etc. Curcumin plays the antitumor effect by directly promoting tumor cell death and reducing tumor cells' invasive ability. Curcumin exerts the therapeutic effect mainly by inhibiting the nuclear factor-κB (NF-κB) signal pathway, inhibiting the production of cyclooxygenase-2 (COX-2), promoting the expression of caspase-9, and directly inducing reactive oxygen species (ROS) production in tumor cells. Curcumin nanoparticles can solve curcumin's shortcomings, such as poor water solubility and high metabolic rate, and can be effectively used in antitumor therapy. Curcumin nanoparticles can improve the prognosis and quality of life of tumor patients by using as adjuvants to enhance the sensitivity of tumors to non-invasive therapy and reduce the side effects, especially cardiotoxicity. In this paper, we collect and analyze the literature of relevant databases. It is pointed out that future research on curcumin tends to alleviate the adverse reactions caused by treatment, which is of more significance to tumor patients.

Curcumin-shellac nanoparticle-loaded GelMA/SilMA hydrogel for colorectal cancer therapy

In this study, a novel approach was employed to develop a therapeutic system for colorectal cancer treatment. Specifically, a GelMA/SilMA hydrogel loaded with curcumin-shellac nanoparticles (Cur@Lac NPs) was created. A microfluidic swirl mixer was utilized to formulate stable Cur@Lac NPs, ensuring their consistent and effective encapsulation. The pH-specific release of curcumin from the NPs demonstrated their potential for colon cancer treatment. By carefully regulating the ratio of GelMA (gelatin methacrylate) and SilMA (silk fibroin methacrylate), a GelMA/SilMA dual network hydrogel was generated, offering controlled release and degradation capabilities. The incorporation of SilMA notably enhanced the mechanical properties of the dual network matrix, improving compression resistance and mitigating deformation. This mechanical improvement is crucial for maintaining the structural integrity of the hydrogel during in vivo applications. In comparison to the direct incubation of curcumin, the strategy of encapsulating curcumin into NPs and embedding them within the GelMA/SilMA hydrogel resulted in more controlled release mechanisms. This controlled release was achieved through the disintegration of the NPs and the swelling and degradation of the hydrogel matrix. The encapsulating strategy also demonstrated enhanced cellular uptake of curcumin, leveraging the advantages of both NPs and in-situ hydrogel injection. This combination ensures a more efficient and sustained delivery of the therapeutic agent directly to the tumor site. Overall, this approach holds significant promise as a smart drug delivery system, potentially improving the efficacy of colorectal cancer treatments by providing targeted, controlled, and sustained drug release with enhanced mechanical stability and biocompatibility.

The Homoleptic Curcumin-Copper Single Crystal (ML2): A Long Awaited Breakthrough in the Field of Curcumin Metal Complexes

The first single crystal structure of the homoleptic copper (II) ML2 complex (M=Cu (II), L = curcumin) was obtained and its structure was elucidated by X-ray diffraction showing a square planar geometry, also confirmed by EPR. The supramolecular arrangement is supported by C-H···O interactions and the solvent (MeOH) plays an important role in stabilizing the crystal packing Crystallinity was additionally assessed by XRD patterns. The log P value of the complex (2.3 ± 0.15) was determined showing the improvement in water solubility. The cytotoxic activity of the complex against six cancer cell lines substantially surpasses that of curcumin itself, and it is particularly selective against leukemia (K562) and human glioblastoma (U251) cell lines, with similar antioxidant activity to BHT. This constitutes the first crystal structure of pristine curcumin complexed with a metal ion.

High Yield Synthesis of Curcumin and Symmetric Curcuminoids: A "Click" and "Unclick" Chemistry Approach

The worldwide known and employed spice of Asian origin, turmeric, receives significant attention due to its numerous purported medicinal properties. Herein, we report an optimized synthesis of curcumin and symmetric curcuminoids of aromatic (bisdemethoxycurcumin) and heterocyclic type, with yields going from good to excellent using the cyclic difluoro-boronate derivative of acetylacetone prepared by reaction of 2,4-pentanedione with boron trifluoride in THF (ca. 95%). The subsequent cleavage of the BF₂ group is of significant importance for achieving a high overall yield in this two-step procedure. Such cleavage occurs by treatment with hydrated alumina (Al₂O₃) or silica (SiO₂) oxides, thus allowing the target heptanoids obtained in high yields as an amorphous powder to be filtered off directly from the reaction media. Furthermore, crystallization instead of chromatographic procedures provides a straightforward purification step. The ease and efficiency with which the present methodology can be applied to synthesizing the title compounds earns the terms "click" and "unclick" applied to describe particularly straightforward, efficient reactions. Furthermore, the methodology offers a simple, versatile, fast, and economical synthetic alternative for the obtention of curcumin (85% yield), bis-demethoxycurcumin (78% yield), and the symmetrical heterocyclic curcuminoids (80-92% yield), in pure form and excellent yields.

Thymol has anticancer effects in U-87 human malignant glioblastoma cells

BACKGROUND

Thymol (2-isopropyl-5-methylphenol) is a colorless crystalline derivative of cymene, that possesses pleotropic pharmacological properties, including analgesic, antibacterial, antispasmodic, and anti-inflammatory activities. Thymol has also been recognized for its beneficial effect as an anti-tumor agent, but the precise mechanism for this has not been fully elucidated. We aimed to identifying whether thymol exerts anti-cancer activity in human U-87 malignant glioblastoma (GB) cells (U-87).

METHODS AND RESULTS

Cell viability and apoptosis was evaluated in U-87 cells treated with thymol at different concentrations. Reactive oxygen species (ROS) production, mRNA expressions of apoptosis-related genes and cell cycle characteristics were assessed. The cytotoxic activity of the co-exposure of thymol and temozolomide (TMZ) was also evaluated. The half-maximal inhibitory concentration (IC50) of thymol in the U-87 cells was 230 μM assessed at 24 h after exposure. Thymol did not exhibit any cytotoxic effects on normal L929 cells at this concentration. Thymol treatment increased the expression of Bax and p53, and also increased apoptotic cell death, and excessive generation of ROS. Moreover, the cytotoxic activity of thymol on the U-87 cells may be related to the arrest of the cell cycle at the G0/G1 interface. Combination therapy showed that the cytotoxic effects of thymol synergized with TMZ, and combined treatment had more cytotoxic potential compared to either of the agents alone.

CONCLUSIONS

Our data indicate the potential cytotoxic activities of thymol on U-87 cells. Further studies are required to evaluate the spectrum of the antitumor activity of thymol on GB cells.

Molecular Mechanism of Curcumin and Its Analogs as Multifunctional Compounds against Pancreatic Cancer

Pancreatic cancer (PC) is one of the most common malignant tumors with a poor prognosis and high mortality. Surgical resection is the most effective treatment for PC; however, only a minority of patients have resectable tumors. Chemotherapy is the primary treatment for PC. Curcumin is a natural chemical substance obtained from plants with a wide range of pharmacological activities. Research evidence suggests that curcumin can influence PC development through multiple molecular mechanisms. The synthesis of novel curcumin analogs and preparation of curcumin nano-formulations are effective strategies to overcome the low bioavailability of curcumin in the treatment of PC. This review aims to summarize the mechanisms of action of curcumin in preclinical and clinical studies on PC and research progress in enhancing its bioavailability.

Gut microbiota: impacts on gastrointestinal cancer immunotherapy

The association of gut microbiota with gastrointestinal carcinogenesis has been heavily investigated since the recent advance in sequencing technology. Accumulating evidence has revealed the critical roles of commensal microbes in cancer progression. Given by its importance, emerging studies have focussed on targeting microbiota to ameliorate therapeutic effectiveness. It is now clear that the microbial community is closely related to the efficacy of chemotherapy, while the correlation of microbiota with immunotherapy is much less studied. Herein, we review the up-to-date findings on the influence of gut microbiota on three common immunotherapies including adoptive cell transfer, immune checkpoint blockade, and CpG-oligodeoxynucleotide therapy. We then explore three microbiota-targeted strategies that may improve treatment efficacy, involving dietary intervention, probiotics supplementation, and fecal microbiota transplantation.

Colorectal Cancer in North-Eastern Iran: a retrospective, comparative study of early-onset and late-onset cases based on data from the Iranian hereditary colorectal cancer registry

BACKGROUND

The incidence rate of colorectal cancer (CRC) is increasing among patients below 50 years of age. The reason for this is unclear, but could have to do with the fact that indicative variables, such as tumour location, gender preference and genetic preponderance have not been followed up in a consistent mann er. The current study was primarily conducted to improve the hereditary CRC screening programme by assessing the demographic and clinicopathological characteristics of early-onset CRC compared to late-onset CRC in northeast Iran.

METHODS

This retrospective study, carried out over a three-year follow-up period (2014-2017), included 562 consecutive CRCs diagnosed in three Mashhad city hospital laboratories in north-eastern Iran. We applied comparative analysis of pathological and hereditary features together with information on the presence of mismatch repair (MMR) gene deficiency with respect to recovery versus mortality. Patients with mutations resulting in absence of the MMR gene MLH1 protein product and normal BRAF status were considered to be at high risk of Lynch syndrome (LS). Analyses using R studio software were performed on early-onset CRC (n = 222) and late-onset CRC (n = 340), corresponding to patients ≤50 years of age and patients > 50 years.

RESULTS

From an age-of-onset point of view, the distribution between the genders differed with females showing a higher proportion of early-onset CRC than men (56% vs. 44%), while the late-onset CRC disparity was less pronounced (48% vs. 52%). The mean age of all participants was 55.6 ± 14.8 years, with 40.3 ± 7.3 years for early-onset CRC and 65.1 ± 9.3 years for late-onset CRC. With respect to anatomical tumour location (distal, rectal and proximal), the frequencies were 61, 28 and 11%, respectively, but the variation did not reach statistical significance. However, there was a dramatic difference with regard to the history of CRC in second-degree relatives between two age categories, with much higher numbers of family-related CRCs in the early-onset group. Expression of the MLH1 and PMS2 genes were significantly different between recovered and deceased, while this finding was not observed with regard to the MSH6 and the MSH2 genes. Mortality was significantly higher in those at high risk of LS.

CONCLUSION

The variation of demographic, pathological and genetic characteristics between early-onset and late-onset CRC emphasizes the need for a well-defined algorithm to identify high-risk patients.

Polyethylene glycol triggers the anti-cancer impact of curcumin nanoparticles in sw-1736 thyroid cancer cells

Curcumin has been recognized as an effective anticancer agent. However, due to its hydrophobic property, the cell absorption is not satisfied. Herein, the curcumin nanoparticles were prepared in the presence of polyethylene glycol 6000 (PEG6000) to reduce its elimination by immune system. For first time, not only the curcumin was encapsulated within the niosome nanoparticles modified by PEG, there are no reports related to the anticancer property of curcumin against thyroid cancers. The nanoparticles was developed and its anticancer was studied on sw-1736 cancer cell line. The nanoparticles were examined by scanning electron microscopy (SEM) and dynamic light scattering (DLS). Also, the release profile of curcumin, the IC50 concentration, the radical amount and the gene expression were evaluated. The optimized nanoparticles showed a diameter of 212 ± 31 nm by SEM and the encapsulation efficiency and loading capacity of 76% and 16.8% respectively. DLS confirmed the polydispersity index (PDI) of 0.596 and the release model was shown a sustained release with the delivery of 68% curcumin after 6 days. Also, the nanoparticles indicated the higher storage stability at 4 °C. After the cell treatment, the apoptotic bodies were appeared and IC50 was obtained as 0.159 mM. Moreover, the generated radicals by the treated cells was 86% after 72 h and the gene pattern indicated the bax/bcl2 ratio of 6.83 confirming the apoptosis effect of the nanoparticles. The results approved the nanoparticles could be suggested as an anticancer drug candidate for thyroid cancers. The encapsulated curcumin within the niosome nanoparticles modified with PEG, could be released and up-taken by the thyroid cancer cell line due to the same hydrophobic property of cell membrane and the niosome particles. The reaction between curcumin and cellular components generates radicals and activates the apoptotic pathway. The corresponding reaction finally makes cell death.

Exosomes: Emerging modulators of signal transduction in colorectal cancer from molecular understanding to clinical application

Exosomes are small cell derived membrane nano-vesicles that carry various components including lipids, proteins and nucleic acids. There is accumulating evidence that exosomes have a role in tumorigenesis, tumor invasiveness and metastasis. Furthermore, oncogene mutation may influence exosome release from tumor cells. Exosomes may induce colorectal cancer by altering signaling cascades such as the Wnt/β-catenin and KRAS pathways that are involved in cell proliferation, apoptosis, dissemination, angiogenesis, and drug resistance. The aim of this review was to overview recent findings evaluating the association between tumor cells-derived exosomes and their content in modulating signaling pathways in colorectal cancer.

Targeting AMPK by Statins: A Potential Therapeutic Approach

Statins are a group of lipid-lowering drugs that inhibit cholesterol biosynthesis and have anti-inflammatory, anti-tumor, and immunomodulatory properties. Several lines of evidence indicate that statins regulate multiple proteins associated with the regulation of differing cellular pathways. The 5'-adenosine monophosphate-activated protein kinase (AMPK) pathway plays an important role in metabolism homeostasis with effects on cellular processes including apoptosis and the inflammatory responses through several pathways. Recently, it has been shown that statins can affect the AMPK pathway in differing physiological and pathological ways, resulting in anti-cancer, cardio-protective, neuro-protective, and anti-tubercular effects; additionally, they have therapeutic effects on non-alcoholic fatty liver disease and diabetes mellitus-associated complications. Statins activate AMPK as an energy sensor that inhibits cell proliferation and induces apoptosis in cancer cells, whilst exerting its cardio-protective effects through inhibition of inflammation and fibrosis, and promotion of angiogenesis. Furthermore, statin-associated AMPK activation leads to decreased lipid accumulation and decreased amyloid beta deposition in the liver and brain, respectively, and may have therapeutic effects on the liver and neurons. In this review, we summarize the results of studies of AMPK-associated therapeutic effects of statins in different pathological conditions.

Anticancer Mechanism of Curcumin on Human Glioblastoma

Glioblastoma (GBM) is the most malignant brain tumor and accounts for most adult brain tumors. Current available treatment options for GBM are multimodal, which include surgical resection, radiation, and chemotherapy. Despite the significant advances in diagnostic and therapeutic approaches, GBM remains largely resistant to treatment, with a poor median survival rate between 12 and 18 months. With increasing drug resistance, the introduction of phytochemicals into current GBM treatment has become a potential strategy to combat GBM. Phytochemicals possess multifarious bioactivities with multitarget sites and comparatively marginal toxicity. Among them, curcumin is the most studied compound described as a potential anticancer agent due to its multi-targeted signaling/molecular pathways properties. Curcumin possesses the ability to modulate the core pathways involved in GBM cell proliferation, apoptosis, cell cycle arrest, autophagy, paraptosis, oxidative stress, and tumor cell motility. This review discusses curcumin’s anticancer mechanism through modulation of Rb, p53, MAPK, P13K/Akt, JAK/STAT, Shh, and NF-κB pathways, which are commonly involved and dysregulated in preclinical and clinical GBM models. In addition, limitation issues such as bioavailability, pharmacokinetics perspectives strategies, and clinical trials were discussed.

Curcumin- and Piperine-Loaded Emulsomes as Combinational Treatment Approach Enhance the Anticancer Activity of Curcumin on HCT116 Colorectal Cancer Model

Combination chemotherapy, administrating two chemotherapeutic agents concurrently, comes into prominence, as the heterogeneity or the level of the disease necessitates a collaborative action. Curcumin, isolated from turmeric, and piperine, isolated from black long pepper, are two dietary polyphenols studied for their intrinsic anti-cancer properties against various cancer types including colorectal cancer (CRC). Furthermore, piperine improves the therapeutic effect of curcumin. Addressing this mutual behavior, this study combines curcumin and piperine within emulsome nanoformulations. Curcumin- (CurcuEmulsomes) and piperine-loaded emulsomes (PiperineEmulsomes) have established a uniform, stable, spherical dispersion with average diameters of 184.21 and 248.76 nm, respectively. The solid tripalmitin inner core achieved encapsulation capacities of up to 0.10 mg/ml curcumin and 0.09 mg/ml piperine content. While piperine treatment alone - in its both free and emulsome forms - showed no inhibition in the proliferation of HCT116 cells in vitro, its presence as the second drug agent enhanced curcumin's effect. Combination of 7 μM PiperineEmulsome and 25 μM CurcuEmulsome concentrations was found to be most effective with an inhibition of cell proliferation of about 50% viability. Cell cycle arrest at G2/M phase and induced apoptosis verified the improved anti-cancer characteristics of the therapy. While CurcuEmulsomes achieved a fourfold increase in Caspase 3 level, combination of treatment with PiperineEulsomes achieved a sixfold increase in the level of this apoptotic marker. Combinational treatment of HCT116 cells with CurcuEmulsomes and PiperineEmulsomes improved the anticancer activity of the compounds and highlighted the potential of the approach for further in vivo studies.

Curcumin Attenuates Oxaliplatin-Induced Liver Injury and Oxidative Stress by Activating the Nrf2 Pathway

Purpose

Oxaliplatin (OXA)-induced liver injury is one of the main limiting factors affecting the efficacy of OXA-based chemotherapy in patients with colorectal liver metastases. In addition, oxidative stress is an important pathophysiological mechanism of OXA-induced liver injury. Therefore, dietary antioxidants may decrease or prevent hepatic toxicity in vivo and be beneficial to OXA-based chemotherapy.

Methods

An experimental OXA-induced liver injury animal model was established, and the protective effects of curcumin (CUR) against OXA-induced liver injury were investigated. ELISA was used to determine the levels of MDA, SOD, CAT, and GSH in liver tissue. The effect of CUR treatment on the expression of cytokines and the Nrf2 pathway was determined by real-time PCR and Western blotting.

Results

CUR treatment alleviated OXA-induced hepatic pathological damage and splenomegaly. The protective effect of CUR was demonstrated to be correlated with inhibition of oxidative stress, inflammation, and the coagulation system. Furthermore, Western blotting revealed that CUR treatment reverses the suppression of Nrf2 nuclear translocation and increases the expression of HO-1 and NOQ1 in mice with OXA-induced liver injury. Moreover, the Nrf2 activation and hepatoprotective effect of CUR were abolished by brusatol.

Conclusion

Curcumin attenuates oxaliplatin-induced liver injury and oxidative stress by activating the Nrf2 pathway, which suggests that CUR may be potentially used in the prevention and treatment of OXA-induced liver injury.

Phytochemicals and Gastrointestinal Cancer: Cellular Mechanisms and Effects to Change Cancer Progression

Gastrointestinal (GI) cancer is a prevailing global health disease with a high incidence rate which varies by region. It is a huge economic burden on health care providers. GI cancer affects different organs in the body such as the gastric organs, colon, esophagus, intestine, and pancreas. Internal and external factors like smoking, obesity, urbanization, genetic mutations, and prevalence of Helicobacter pylori and Hepatitis B and Hepatitis C viral infections could increase the risk of GI cancer. Phytochemicals are non-nutritive bioactive secondary compounds abundantly found in fruits, grains, and vegetables. Consumption of phytochemicals may protect against chronic diseases like cardiovascular disease, neurodegenerative disease, and cancer. Multiple studies have assessed the chemoprotective effect of selected phytochemicals in GI cancer, offering support to their potential towards reducing the pathogenesis of the disease. The aim of this review was to summarize the current knowledge addressing the anti-cancerous effects of selected dietary phytochemicals on GI cancer and their molecular activities on selected mechanisms, i.e., nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), detoxification enzymes, adenosine monophosphate activated protein kinase (AMPK), wingless-related integration site/β-catenin (wingless-related integration site (Wnt) β-catenin, cell apoptosis, phosphoinositide 3-kinases (PI3K)/ protein kinase B AKT/ mammalian target of rapamycin (mTOR), and mitogen-activated protein kinase (MAPK). In this review phytochemicals were classified into four main categories: (i) carotenoids, including lutein, lycopene, and β-carotene; (ii) proanthocyanidins, including quercetin and ellagic acid; (iii) organosulfur compounds, including allicin, allyl propyl disulphide, asparagusic acid, and sulforaphane; and (iv) other phytochemicals including pectin, curcumins, p-coumaric acid and ferulic acid. Overall, phytochemicals improve cancer prognosis through the downregulation of β-catenin phosphorylation, therefore enhancing apoptosis, and upregulation of the AMPK pathway, which supports cellular homeostasis. Nevertheless, more studies are needed to provide a better understanding of the mechanism of cancer treatment using phytochemicals and possible side effects associated with this approach.

Potential of phytochemicals as immune-regulatory compounds in atopic diseases: A review

Atopic diseases (atopic dermatitis, asthma and allergic rhinitis) affects a huge number of people around the world and their incidence rate is on rise. Atopic dermatitis (AD) is more prevalent in paediatric population which sensitizes an individual to develop allergic rhinitis and asthma later in life. The complex pathogenesis of these allergic diseases though involves numerous cellular signalling pathways but redox imbalance has been reported to be critical for induction/perpetuation of inflammatory process under such conditions. The realm of complementary and alternative medicine has gained greater attention because of the reported anti-oxidant/anti-inflammatory properties. Several case studies of treating atopic diseases with homeopathic remedies have provided positive results. Likewise, pre-clinical studies suggest that various natural compounds suppress allergic response via exhibiting their anti-oxidant potential. Despite the reported beneficial effects of phytochemicals in experimental model system, the clinical success has not been documented so far. It appears that poor absorption and bioavailability of natural compounds may be one of the reasons for realizing their full potential. The current paper throws light on impact of phytochemicals in the redox linked cellular and signalling pathways that may be critical in manifestation of atopic diseases. Further, an effort has been made to identify the gaps in the area so that future strategies could be evolved to exploit the medicinal value of various phytochemicals for an improved efficiency.

Lipid Nanoparticles and Active Natural Compounds: A Perfect Combination for Pharmaceutical Applications

Phytochemicals represent an important class of bioactive compounds characterized by significant health benefits. Notwithstanding these important features, their potential therapeutic properties suffer from poor water solubility and membrane permeability limiting their approach to nutraceutical and pharmaceutical applications. Lipid nanoparticles are well known carrier systems endowed with high biodegradation and an extraordinary biocompatible chemical nature, successfully used as platform for advanced delivery of many active compounds, including the oral, topical and systemic routes. This article is aimed at reviewing the last ten years of studies about the application of lipid nanoparticles in active natural compounds reporting examples and advantages of these colloidal carrier systems.

Curcumin suppresses osteogenesis by inducing miR-126a-3p and subsequently suppressing the WNT/LRP6 pathway

Curcumin, a natural phenolic biphenyl compound derived from the plant Curcuma longa, modulates multiple steps of carcinogenesis partly by affecting the expression of miRNAs. Interestingly, cancer development shares many of the same signalling pathways with bone formation. Reduced bone mass creates favourable conditions for tumor metastasis. However, the effects and mechanism of curcumin on bone formation and osteogenesis are relatively unknown and controversial. We demonstrated that curcumin inhibited osteogenesis of human adipose-derived mesenchymal stem cells (hADSCs) in a concentration-dependent manner. In hADSCs, curcumin modulates the expression of a series of miRNAs, including miR-126a-3p, during osteogenesis. Overexpression or inhibition of miR-126a-3p is required for the effect of curcumin on osteogenesis. Further investigation indicated that miR-126a-3p directly targets and inhibits LRP6 through binding to its 3’-UTR, and then blocks WNT activation. Our findings suggest that the use of curcumin as an anti-tumor agent may lead to decreased bone mass through the suppression of osteogenesis. Knowing whether the long-term or high doses use of curcumin will cause decreased bone mass and bone density, which might increase the potential threat of tumor metastasis, also requires a neutral assessment of the role of curcumin in both regulating bone formation and bone absorption.

Mechanism of Apoptosis Induced by Curcumin in Colorectal Cancer

Colorectal cancer (CRC) is among the top three cancer with higher incident and mortality rate worldwide. It is estimated that about over than 1.1 million of death and 2.2 million new cases by the year 2030. The current treatment modalities with the usage of chemo drugs such as FOLFOX and FOLFIRI, surgery and radiotherapy, which are usually accompanied with major side effects, are rarely cured along with poor survival rate and at higher recurrence outcome. This trigger the needs of exploring new natural compounds with anti-cancer properties which possess fewer side effects. Curcumin, a common spice used in ancient medicine was found to induce apoptosis by targeting various molecules and signaling pathways involved in CRC. Disruption of the homeostatic balance between cell proliferation and apoptosis could be one of the promoting factors in colorectal cancer progression. In this review, we describe the current knowledge of apoptosis regulation by curcumin in CRC with regard to molecular targets and associated signaling pathways.

Potential Mechanisms of Action of Curcumin for Cancer Prevention: Focus on Cellular Signaling Pathways and miRNAs

Despite significant progressions in treatment modalities over the last decade, either cancer incidence or mortality is continuously on the rise throughout the world. Current anticancer agents display limited efficacy, accompanied by severe side effects. In order to improve therapeutic outcomes in patients with cancer, it is crucial to identify novel, highly efficacious pharmacological agents. Curcumin, a hydrophobic polyphenol extracted from turmeric, has gained increasing attention due to its powerful anticancer properties. Curcumin can inhibit the growth, invasion and metastasis of various cancers. The anticancer mechanisms of curcumin have been extensively studied. The anticancer effects of curcumin are mainly mediated through its regulation of multiple cellular signaling pathways, including Wnt/β-catenin, PI3K/Akt, JAK/STAT, MAPK, p53 and NF-ĸB signaling pathways. Moreover, curcumin also orchestrates the expression and activity of oncogenic and tumor-suppressive miRNAs. In this review, we summarized the regulation of these signaling pathways by curcumin in different cancers. We also discussed the modulatory function of curcumin in the downregulation of oncogenic miRNAs and the upregulation of tumor-suppressive miRNAs. An in-depth understanding of the anticancer mechanisms of curcumin will be helpful for developing this promising compound as a therapeutic agent in clinical management of cancer.

Beneficial Role of Phytochemicals on Oxidative Stress and Age-Related Diseases

Aging is related to a number of functional and morphological changes leading to progressive decline of the biological functions of an organism. Reactive Oxygen Species (ROS), released by several endogenous and exogenous processes, may cause important oxidative damage to DNA, proteins, and lipids, leading to important cellular dysfunctions. The imbalance between ROS production and antioxidant defenses brings to oxidative stress conditions and, related to accumulation of ROS, aging-associated diseases. The purpose of this review is to provide an overview of the most relevant data reported in literature on the natural compounds, mainly phytochemicals, with antioxidant activity and their potential protective effects on age-related diseases such as metabolic syndrome, diabetes, cardiovascular disease, cancer, neurodegenerative disease, and chronic inflammation, and possibly lower side effects, when compared to other drugs.

Growth and Proliferation of Renal Cell Carcinoma Cells Is Blocked by Low Curcumin Concentrations Combined with Visible Light Irradiation

The anti-cancer properties of curcumin in vitro have been documented. However, its clinical use is limited due to rapid metabolization. Since irradiation of curcumin has been found to increase its anti-cancer effect on several tumor types, this investigation was designed to determine whether irradiation with visible light may enhance the anti-tumor effects of low-dosed curcumin on renal cell carcinoma (RCC) cell growth and proliferation. A498, Caki1, and KTCTL-26 cells were incubated with curcumin (0.1–0.4 µg/mL) and irradiated with 1.65 J/cm² visible light for 5 min. Controls were exposed to curcumin or light alone or remained untreated. Curcumin plus light, but not curcumin or light exposure alone altered growth, proliferation, and apoptosis of all three RCC tumor cell lines. Cells were arrested in the G0/G1 phase of the cell cycle. Phosphorylated (p) CDK1 and pCDK2, along with their counter-receptors Cyclin B and A decreased, whereas p27 increased. Akt-mTOR-signaling was suppressed, the pro-apoptotic protein Bcl-2 became elevated, and the anti-apoptotic protein Bax diminished. H3 acetylation was elevated when cells were treated with curcumin plus light, pointing to an epigenetic mechanism. The present findings substantiate the potential of combining low curcumin concentrations and light as a new therapeutic concept to increase the efficacy of curcumin in RCC.

Cancer-Associated Fibroblasts in Pancreatic Cancer: Should They Be Deleted or Reeducated?

Pancreatic ductal adenocarcinoma is characterized by an extensive stromal response called desmoplasia. Within the tumor stroma, cancer-associated fibroblasts (CAFs) are the primary cell type. CAFs have been shown to play a role in pancreatic cancer progression; they secrete growth factors, inflammatory cytokines, and chemokines that stimulate signaling pathways in cancer cells and modulate the cancer biology toward increased aggressiveness. Therefore, targeting CAFs may serve as a powerful weapon against pancreatic cancer and improve therapeutic effects. However, a previous study aiming to deplete CAFs by inhibiting sonic Hedgehog signaling failed to show any benefit in survival time of pancreatic cancer patients. We reported that the natural product curcumin reeducated CAFs in pancreatic cancer treatment. A low concentration of curcumin reversed the activation of fibroblasts without exhibiting growth suppression effects. In addition, curcumin suppressed CAF-induced pancreatic cancer cell migration and invasion in vitro and lung metastasis in vivo. The results of our study suggest that active CAFs can be inactivated by certain natural products such as curcumin. Reeducation of CAFs back to their normal state, rather than their indiscriminate depletion, may broaden our view in the development of therapeutic options for the treatment of pancreatic cancer.

Curcumin Induces Autophagy via Inhibition of Yes-Associated Protein (YAP) in Human Colon Cancer Cells

BACKGROUND Colon cancer is one of the most common cancers and it is the fourth leading cause of cancer-related deaths worldwide. YAP can promote cell proliferation and inhibit apoptosis, leading to loss of cell contact inhibition and promoting malignant cell transformation. MATERIAL AND METHODS In this study we analyzed the effects of different curcumin concentrations on the proliferation of colon cancer cells using MTT and colony formation assays. Western blot detection was performed to confirm the YAP, LC3-II, and P62 expression. RESULTS Curcumin inhibited proliferation and promoted colon cancer cell autophagy. In addition, Western blot results indicated that curcumin suppressed YAP expression in colon cancer cells. To assess the mechanism, we treated the cell lines with curcumin and assessed YAP overexpression and YAP knockdown. The results revealed that curcumin inhibits the proliferation and promotes autophagy of these cell lines. Western blot results showed that curcumin reversed the effect of YAP in colon cancer cells. CONCLUSIONS Our results suggest that YAP has great promise for treatment of colon cancer and that it might be a potential diagnostic marker for colon cancer.

Blockade of LAG3 enhances responses of tumor-infiltrating T cells in mismatch repair-proficient liver metastases of colorectal cancer

Purpose: Liver metastasis develops in >50% of patients with colorectal cancer (CRC), and is a leading cause of CRC-related mortality. We aimed to identify which inhibitory immune checkpoint pathways can be targeted to enhance functionality of intra-tumoral T-cells in mismatch repair-proficient liver metastases of colorectal cancer (LM-CRC). Methodology: Intra-tumoral expression of multiple inhibitory molecules was compared among mismatch repair-proficient LM-CRC, peritoneal metastases of colorectal cancer (PM-CRC) and primary CRC. Expression of inhibitory molecules was also analyzed on leukocytes isolated from paired resected metastatic liver tumors, tumor-free liver tissues, and blood of patients with mismatch repair-proficient LM-CRC. The effects of blocking inhibitory pathways on tumor-infiltrating T-cell responses were studied in ex vivo functional assays. Results: Mismatch repair-proficient LM-CRC showed higher expression of inhibitory receptors on intra-tumoral T-cells and contained higher proportions of CD8⁺ T-cells, dendritic cells and monocytes than mismatch repair-proficient primary CRC and/or PM-CRC. Inhibitory receptors LAG3, PD-1, TIM3 and CTLA4 were higher expressed on CD8⁺ T-cells, CD4⁺ T-helper and/or regulatory T-cells in LM-CRC tumors compared with tumor-free liver and blood. Antibody blockade of LAG3 or PD-L1 increased proliferation and effector cytokine production of intra-tumoral T-cells isolated from LM-CRC in response to both polyclonal and autologous tumor-specific stimulations. Higher LAG3 expression on intra-tumoral CD8⁺ T-cells associated with longer progression-free survival of LM-CRC patients. Conclusion: Mismatch repair-proficient LM-CRC may be more sensitive to immune checkpoint inhibitors than mismatch repair-proficient primary CRC. Blocking LAG3 enhances tumor-infiltrating T-cell responses of mismatch repair-proficient LM-CRC, and therefore may be a new promising immunotherapeutic target for LM-CRC.

Wnt Signalling-Targeted Therapy in the CMS2 Tumour Subtype: A New Paradigm in CRC Treatment?

Colorectal cancers (CRC) belonging to the consensus molecular subtype 2 (CMS2) have the highest incidence rate, affect mainly the distal colon and rectum, and are characterized by marked Wnt/β-catenin/Transcription Factor 7-Like 2 (TCF7L2) pathway activation and also by activation of epidermal growth factor receptor (EGFR) signalling. Despite having the highest overall survival, CMS2 tumours are often diagnosed at stage III when an adjuvant chemotherapy-based regimen is recommended. Nevertheless, colorectal cancer stem cells (CSCs) and circulating tumour cells may still evade the current therapeutic options and metastasize, stressing the need to develop more tailored therapeutic strategies. For example, activation of EGFR signalling is being used as a target for tailored therapy, however, therapy resistance is frequently observed. Therefore, targeting the Wnt signalling axis represents an additional therapeutic strategy, considering that CMS2 tumours are "Wnt-addicted". Several efforts have been made to identify Wnt antagonists, either of synthetic or natural origin. However, an inverse gradient of Wnt/β-catenin/TCF7L2 signalling activity during CRC progression has been suggested, with early stage and metastatic tumours displaying high and low Wnt signalling activities, respectively, which lead us to revisit the "just-right" signalling model. This may pinpoint the use of Wnt signalling agonists instead of antagonists for treatment of metastatic stages, in a context-dependent fashion. Moreover, the poor immunogenicity of these tumours challenges the use of recently emerged immunotherapies. This chapter makes a journey about CMS2 tumour characterization, their conventional treatment, and how modulation of Wnt signalling or immune response may be applied to CRC therapy. It describes the newest findings in this field and indicates where more research is required.