Amelioration of immune cell number depletion and potentiation of depressed detoxification system of tumor-bearing mice by curcumin

Alteration of functionality and differentiation directed by changing gene expression patterns in myeloid-derived suppressor cells (MDSCs) in tumor microenvironment and bone marrow through early to terminal phase of tumor progression

Myeloid-derived suppressor cells are heterogenous immature myeloid lineage cells that can differentiate into neutrophils, monocytes, and dendritic cells as well. These cells have been characterized to have potent immunosuppressive capacity in neoplasia and a neoplastic chronic inflammatory microenvironment. Increased accumulation of myeloid-derived suppressor cells was reported with poor clinical outcomes in patients. They support neoplastic progression by abrogating antitumor immunity through inhibition of lymphocyte functions and directly by facilitating tumor development. Yet the shifting genetic signatures of this myeloid lineage cell toward immunosuppressive functionality in progressive tumor development remain elusive. We have attempted to identify the gene expression profile using lineage-specific markers of these unique myeloid lineage cells in a tumor microenvironment and bone marrow using a liquid transplantable mice tumor model to trace the changing influence of the tumor microenvironment on myeloid-derived suppressor cells. We analyzed the phenotype, functional shift, suppressive activity, differentiation status, and microarray-based gene expression profile of CD11b+Gr1+ lineage-specific cells isolated from the tumor microenvironment and bone marrow of 4 stages of tumor-bearing mice and compared them with control counterparts. Our analysis of differentially expressed genes of myeloid-derived suppressor cells isolated from bone marrow and the tumor microenvironment reveals unique gene expression patterns in the bone marrow and tumor microenvironment-derived myeloid-derived suppressor cells. It also suggests T-cell suppressive activity of myeloid-derived suppressor cells progressively increases toward the mid-to-late phase of the tumor and a significant differentiation bias of tumor site myeloid-derived suppressor cells toward macrophages, even in the presence of differentiating agents, indicating potential molecular characteristics of myeloid-derived suppressor cells in different stages of the tumor that can emerge as an intervention target.

Targeted therapies of curcumin focus on its therapeutic benefits in cancers and human health: Molecular signaling pathway-based approaches and future perspectives

The curry powder spices turmeric (Curcuma longa L.), which contains curcumin (diferuloylmethane), an orange-yellow chemical. Polyphenols are the most commonly used sources of curcumin. It combats oxidative stress and inflammation in diseases, such as hyperlipidemia, metabolic syndrome, arthritis, and depression. Most of these benefits are due to their anti-inflammatory and antioxidant properties. Curcumin consumption leads to decreased bioavailability, resulting in limited absorption, quick metabolism, and quick excretion, which hinders health improvement. Numerous factors can increase its bioavailability. Piperine enhances bioavailability when combined with curcumin in a complex. When combined with other enhancing agents, curcumin has a wide spectrum of health benefits. This review evaluates the therapeutic potential of curcumin with a specific emphasis on its approach based on molecular signaling pathways. This study investigated its influence on the progression of cancer, inflammation, and many health-related mechanisms, such as cell proliferation, apoptosis, and metastasis. Curcumin has a significant potential for the prevention and treatment of various diseases. Curcumin modulates several biochemical pathways and targets involved in cancer growth. Despite its limited tissue accumulation and bioavailability when administered orally, curcumin has proven useful. This review provides an in-depth analysis of curcumin's therapeutic applications, its molecular signaling pathway-based approach, and its potential for precision medicine in cancer and human health.

Substituted Thiazole Derivatives Provide Corrective Anti-tumour and Anti-oxidant Activities against Ehrlich Ascites Carcinoma

Novel and effective treatments are urgently needed for cancer, which is still the leading cause of death in the world. Biological characteristics linked to thiazole derivatives span a wide range. Thiazole derivatives are used in the creation of medications for therapy as well. The aim of current study is to evaluate the anticancer and antioxidant properties of the newly synthesized thiazole derivatives, compounds 1 and 2, on Ehrlich ascites carcinoma (EAC) cells in female mice. Our findings indicated that thiazole derivatives, compounds 1 and 2 have anticancer activity by elevating the p53 expression and cytochrome c levels in groups treated with compounds 1 and 2 compared to the positive control group. Furthermore, thiazole derivatives compounds 1 and 2 showed a potent antioxidant effect by increasing enzymatic antioxidants, catalase (CAT) activity, and non-enzymatic antioxidants, GSH, and lowering Malondialdehyde (MDA) in hepatic and renal tissues of treated groups. Additionally, the target compounds were capable of providing corrective effects against EAC-induced biochemical and histopathological changes without harmful side effects. CONCLUSION: The target studied thiazol derivatives compounds were capable of providing corrective effects against EAC-induced without harmful side effects.

Curcuminoids as Anticancer Drugs: Pleiotropic Effects, Potential for Metabolic Reprogramming and Prospects for the Future

The number of published studies on curcuminoids in cancer research, including its lead molecule curcumin and synthetic analogs, has been increasing substantially during the past two decades. Insights on the diversity of inhibitory effects they have produced on a multitude of pathways involved in carcinogenesis and tumor progression have been provided. As this wealth of data was obtained in settings of various experimental and clinical data, this review first aimed at presenting a chronology of discoveries and an update on their complex in vivo effects. Secondly, there are many interesting questions linked to their pleiotropic effects. One of them, a growing research topic, relates to their ability to modulate metabolic reprogramming. This review will also cover the use of curcuminoids as chemosensitizing molecules that can be combined with several anticancer drugs to reverse the phenomenon of multidrug resistance. Finally, current investigations in these three complementary research fields raise several important questions that will be put among the prospects for the future research related to the importance of these molecules in cancer research.

Immunity boosting nutraceuticals: Current trends and challenges

The immune function of the human body is highly influenced by the dietary intake of certain nutrients and bioactive compounds present in foods. The preventive effects of these bioactive ingredients against various diseases have been well investigated. Functional foods are consumed across various diverse cultures, in some form or the other, which provide benefits greater than the basic nutritional needs. Novel functional foods are being developed using novel bioactive ingredients such as probiotics, polyunsaturated fatty acids, and various phytoconstituents, which have a range of immunomodulatory properties. Apart from immunomodulation, these ingredients also affect immunity by their antioxidant, antibacterial, and antiviral properties. The global pandemic of Severe Acute Respiratory Syndrome Coronavirus-2 has forced the scientific community to race against time to find a proper and effective drug or a vaccine. In this review, various non-pharmacological interventions using nutraceuticals and functional foods have been discussed. PRACTICAL APPLICATIONS: Despite a plethora of research being undertaken to understand the immunity boosting properties of the various bioactive present in food, the findings are not translating to nutraceutical products in the market. Immunity has proved to be one of the most important factors for the health and well-being of an individual, especially when the world has been under the grip of the novel coronavirus Severe Acute Respiratory Syndrome Coronavirus-2. The anti-inflammatory properties of various nutraceuticals can come out as potential inhibitors of the various inflammatory processes such as cytokine storms, usually being observed in COVID 19. This review gives an insight into how various nutraceuticals can help in the prevention of various diseases through different mechanisms. The lack of awareness and proper clinical trials pose a challenge to the nutraceutical industry. This review will help and encourage researchers to further design and develop various functional foods, which might help in building immunity.

Curcumin as an Adjuvant to Cancer Immunotherapy

The components of the immune system play a very sincere and crucial role in combating tumors. However, despite their firm efforts of elimination, tumor cells cleverly escape the surveillance process by adopting several immune evasion mechanisms. The conversion of immunogenicity of tumor microenvironment into tolerogenic is considered as a prime reason for tumor immune escape. Therapeutically, different immunotherapies have been adopted to block such immune escaping routes along with better clinical outcomes. Still, the therapies are haunted by several drawbacks. Over time, curcumin has been considered as a potential anti-cancer molecule. Its potentialities have been recorded against the standard hallmarks of cancer such as continuous proliferation, escaping apoptosis, continuous angiogenesis, insensitivity to growth inhibitors, tissue invasion, and metastasis. Hence, the diversity of curcumin functioning has already been established and exploration of its application with immunotherapies might open up a new avenue for scientists and clinicians. In this review, we briefly discuss the tumor's way of immune escaping, followed by various modern immunotherapies that have been used to encounter the escaping paths and their minute flaws. Finally, the conclusion has been drawn with the application of curcumin as a potential immune-adjuvant, which fearlessly could be used with immunotherapies for best outcomes.

Antiproliferative and antioxidant potentials of bioactive edible vegetable fraction of Achyranthes ferruginea Roxb. in cancer cell line

In the present study, the aerial parts of Achyranthes ferruginea underwent investigation of their in vitro antioxidant and free radical-scavenging activities in cell-free conditions, their phytoconstituents using gas chromatography-mass spectrometry (GC-MS), and their cytotoxic activity in HeLa cells. A. ferruginea was extracted with 80% methanol and successively fractionated with solvents to yield petroleum ether (PEF), chloroform (CHF), ethyl acetate (EAF), and aqueous (AQF) fractions. GC-MS analysis revealed that CHF contained ten phytoconstituents, including different forms of octadecanoic acid methyl esters. The total antioxidant and ferric-reducing antioxidant capacities of the extracts and the standard catechin (CA) were as follows: CA >CHF >PEF >CME (crude methanolic extract) >EAF >AQF, and CA >CHF >EAF >PEF >AQF >CME, respectively. CHF showed the highest DPPH-free radical-scavenging activity, with a median inhibitory concentration of 10.5 ± 0.28 µg/ml, which was slightly higher than that of the standard butylated hydroxytoluene (12.0 ± 0.09 µg/ml). In the hydroxyl radical-scavenging assay, CHF showed identical scavenging activity (9.25 ± 0.73 µg/ml) when compared to CA (10.50 ± 1.06 µg/ml). Moreover, CHF showed strong cytotoxic activity (19.95 ± 1.18 µg/ml) in HeLa cells, which was alike to that of the standards vincristine sulfate and 5-fluorouracil (15.84 ± 1.64 µg/ml and 12.59 ± 1.75 µg/ml, respectively). The in silico study revealed that identified compounds were significantly linked to the targets of various cancer cells and oxidative enzymes. However, online prediction by SwissADME, admetSAR, and PASS showed that it has drug-like, nontoxic, and potential pharmacological actions.

Effects of curcumin complexes on MDA‑MB‑231 breast cancer cell proliferation

Curcumin displays anticancer properties; however, some issues with the drug delivery mode limit its therapeutic use. Although reformulation and derivatization of curcumin have improved its bioavailability, curcumin derivatives may not retain the same anticancer properties as the parent compound. The present study investigated the anticancer properties of two curcumin complexes, the iron‑curcumin [Fe(Cur)3] and boron‑curcumin [B(Cur)2] complexes, in the MDA‑MB‑231 breast cancer cell line. The cellular localization of curcumin, B(Cur)2 and Fe(Cur)3 was determined by fluorescence microscopy. Cell proliferation, migration and invasion were also analysed. Furthermore, apoptosis‑associated proteins were detected by using a proteome profiler array, and ion channel gene expression was analysed by reverse transcription‑quantitative PCR. The results demonstrated that the three compounds were localized in the perinuclear and cytoplasmic regions of the cell, and displayed cytotoxicity with IC50 values of 25, 35 and 8 µM for curcumin, B(Cur)2 and Fe(Cur)3, respectively. In addition, the three compounds inhibited cell invasion, whereas only curcumin and B(Cur)2 inhibited cell migration. Furthermore, cell exposure to curcumin resulted in an increase in the relative expression of the two key proapoptotic proteins, cytochrome c and cleaved caspase‑3, as well as the antiapoptotic protein haem oxygenase‑1. In addition, curcumin increased the expression levels of the voltage‑gated potassium channels Kv2.1 and Kv3.2. Similarly, the expression levels of the chloride channel bestrophin‑1 and the calcium channel coding gene calcium voltage‑gated channel auxiliary subunit γ4 were increased following exposure to curcumin. Taken together, these results indicated that Fe(Cur)3 and B(Cur)2 may display similar anticancer properties as curcumin, suggesting that chemical complexation may be considered as a strategy for improving the potency of curcumin in the treatment of breast cancer.

Targeting Autophagic Pathways by Plant Natural Compounds in Cancer Treatment

Nowadays, natural compounds of plant origin with anticancer effects have gained more attention because of their clinical safety and broad efficacy profiles. Autophagy is a multistep lysosomal degradation pathway that may have a unique potential for clinical benefit in the setting of cancer treatment. To retrieve articles related to the study, the databases of Google Scholar, Web of sciences, Medline and Scopus, using the following keywords: Autophagic pathways; herbal medicine, oncogenic autophagic pathways, tumor-suppressive autophagic pathways, and cancer were searched. Although natural plant compounds such as resveratrol, curcumin, oridonin, gossypol, and paclitaxel have proven anticancer potential via autophagic signaling pathways, there is still a great need to find new natural compounds and investigate the underlying mechanisms, to facilitate their clinical use as potential anticancer agents through autophagic induction.

Prolonged Persistence of Chimeric Antigen Receptor (CAR) T Cell in Adoptive Cancer Immunotherapy: Challenges and Ways Forward

CAR T cell qualities, such as persistence and functionality play important roles in determining the outcome of cancer immunotherapy. In spite of full functionality, it has been shown that poor persistence of CAR T cells can limit an effective antitumor immune response. Here, we outline specific strategies that can be employed to overcome intrinsic and extrinsic barriers to CAR T cell persistence. We also offer our viewpoint on how growing use of CAR T cells in various cancers may require modifications in the intrinsic and extrinsic survival signals of CAR T cells. We anticipate these amendments will additionally provide the rationales for generation of more persistent, and thereby, more effective CAR T cell treatments. CAR T cell qualities, such as persistence and functionality play important roles in determining the outcome of cancer immunotherapy. In spite of full functionality, it has been shown that poor persistence of CAR T cells can limit an effective antitumor immune response. Here, we outline specific strategies that can be employed to overcome intrinsic and extrinsic barriers to CAR T cell persistence. We also offer our viewpoint on how growing use of CAR T cells in various cancers may require modifications in the intrinsic and extrinsic survival signals of CAR T cells. We anticipate these amendments will additionally provide the rationales for generation of more persistent, and thereby, more effective CAR T cell treatments.

Dietary curcumin supplementation effects on blood immunological profile and liver enzymatic activity of laying hens after exposure to high temperature conditions

Various environmental factors affect livestock production but heat stress is a major challenge in the poultry farming. Poultry exposes to high temperature alters blood immunological parameters and liver enzymatic function which in turn, suppress the immunity and disease resistance of chickens. Thus, the purpose of present study was to explore the effect of dietary curcumin supplementation on blood immunological biomarker and liver enzymatic activity of laying hens under heat stress conditions. Experimental groups contained two control groups (normal temperature control (NC) and heat stress control (HC) and 3 heat stress curcumin treatment groups (HT100, HT200 and HT300). Hens in HC group with basal diet and heat stress curcumin treatment groups were exposed 6 h/day heat stress (32 ± 1 °C) from 10:00 a.m. to 16:00 p.m. for 9 week. The results of present study showed that heat stressed curcumin treatment group had improved liver weight, WBC values and immunoglobulin level as compared to untreated HC and NC groups. The available results also indicated that laying hens supplemented with curcumin under high temperature conditions had reduced H/L ratio, serum corticosterone levels, inflammatory cytokines response and liver enzymatic activity (ALT) which enhanced the immunity of laying hens under hot climatic conditions. Therefore, it is concluded that curcumin has ability to combat harsh environmental conditions which can be used as anti-inflammatory and immune booster feed additive in the poultry nutrition.

Bioactivity Evaluation of a Novel Formulated Curcumin

Curcumin has been used as a traditional medicine and/or functional food in several cultures because of its health benefits including anticancer properties. However, poor oral bioavailability of curcumin has limited its oral usage as a food supplement and medical food. Here we formulated curcumin pellets using a solid dispersion technique. The pellets had the advantages of reduced particle size, improved water solubility, and particle porosity. This pellet form led to an improvement in curcumin's oral bioavailability. Additionally, we used the C-Map and Library of Integrated Network-Based Cellular Signatures (LINCS) Unified Environment (CLUE) gene expression database to determine the potential biological functions of formulated curcumin. The results indicated that, similar to conventional curcumin, the formulated curcumin acted as an NF-κB pathway inhibitor. Moreover, ConsensusPathDB database analysis was used to predict possible targets and it revealed that both forms of curcumin exhibit similar biological functions, including apoptosis. Biochemical characterization revealed that both the forms indeed induced apoptosis of hepatocellular carcinoma (HCC) cell lines. We concluded that the formulated curcumin increases the oral bioavailability in animals, and, as expected, retains characteristics similar to conventional curcumin at the cellular level. Our screening platform using big data not only confirms that both the forms of curcumin have similar mechanisms but also predicts the novel mechanism of the formulated curcumin.

Anticancer potential of naturally occurring immunoepigenetic modulators: A promising avenue?

The immune system represents the major primary defense line against carcinogenesis and acts by identifying and eradicating nascent transformed cells. A growing body of evidence is indicating that aberrant epigenetic reprogramming plays a key role in tumor immune escape through: 1) impaired efficient recognition of neoplastic cells by the immune system, resulting from a downregulation or loss of the expression of tumor-associated antigens, human leukocyte antigens, antigen processing and presenting machinery, and costimulatory molecule genes; 2) aberrant expression of immune checkpoint proteins and their ligands; and 3) modification of cytokine profiles and tumor-associated immune cell populations toward an immunosuppressive state in the tumor microenvironment. Consistent with the inherent reversibility of epigenetic alterations, epigenetic drugs, including DNA methyltransferase and histone deacetylase inhibitors, have the unique potential to favorably modify the tumor microenvironment, restore tumor recognition and stimulate an antitumor immune response. The objective of this review is to highlight selected, naturally occurring epigenetic modulators, namely, butyrate, curcumin, (-)-epigallocatechin-3-gallate, resveratrol, romidepsin, and trichostatin A, with a special focus on their antitumor immune properties.

The immunomodulatory potential of natural compounds in tumor-bearing mice and humans

Cancer is considered a fetal disease caused by uncontrolled proliferation and progression of abnormal cells. The most efficient cancer therapies suppress tumor growth, prevent progression and metastasis, and are minimally toxic to normal cells. Natural compounds have shown a variety of chemo-protective effects alone or in combination with standard cancer therapies. Along with better understanding of the dynamic interactions between our immune system and cancer development, nutritional immunology-the use of natural compounds as immunomodulators in cancer patients-has begun to emerge. Cancer cells evolve strategies that target many aspects of the immune system to escape or even edit immune surveillance. Therefore, the immunesuppressive tumor microenvironment is a major obstacle in the development of cancer therapies. Because interaction between the tumor microenvironment and the immune system is a complex topic, this review focuses mainly on human clinical trials and animal studies, and it highlights specific immune cells and their cytokines that have been modulated by natural compounds, including carotenoids, curcumin, resveratrol, EGCG, and β-glucans. These natural compounds have shown promising immune-modulating effects, such as inhibiting myeloid-derived suppressor cells and enhancing natural killer and cytolytic T cells, in tumor-bearing animal models, but their efficacy in cancer patients remains to be determined.

Antineoplastic Activity and Curative Role of Avenanthramides against the Growth of Ehrlich Solid Tumors in Mice

Interest is growing in finding natural sources of effective antitumor agents that generate fewer side effects than conventional chemotherapeutic drugs. Avenanthramides (Avns) are such compounds; these phenolic molecules naturally occur in oats and have antioxidant, anti-inflammatory, and antiproliferative effects making them worthy of further research. The aim of this study is to characterise Avns' curative ability and antineoplastic activity on solid-form Ehrlich tumors. For the study, 75 female mice were randomly and equally allocated to five groups (group 1-control, group 2-DMSO, group 3-positive control receiving Avns, group 4-mice with Ehrlich solid tumor, and group 5-Ehrlich solid tumor treated with Avns). Mice with Ehrlich solid tumors exhibit increased tumor volume; elevated expression of AFP, ALT, AST, Bcl2, CEA, cholesterol, creatinine, urea, MDA, PCNA, potassium, triglycerides, TNF-α, and NF-κB; and a concomitant decline in catalase, GSH, P53, and SOD. In the mice with Ehrlich tumors who received Avns, there appeared to be improvement in NF-κB TNF-α, tumor markers (AFP and CEA), electrolytes, liver and kidney function enzymes, and lipid profiles; reduced MDA level; improved antioxidant parameters; normalised liver protein, P53, and PCNA; and reduced Bcl2 expression. Pathological examination of tumor lesions also indicated improvement. These results suggest that Avns exhibit antineoplastic activity and possess antioxidant properties that enhance the antioxidant defence system, thus reducing the oxidative stress caused by Ehrlich solid tumors.

Curcumin as an anti-inflammatory agent: Implications to radiotherapy and chemotherapy

Cancer is the second cause of death worldwide. Chemotherapy and radiotherapy are the most common modalities for the treatment of cancer. Experimental studies have shown that inflammation plays a central role in tumor resistance and the incidence of several side effects following both chemotherapy and radiotherapy. Inflammation resulting from radiotherapy and chemotherapy is responsible for adverse events such as dermatitis, mucositis, pneumonitis, fibrosis, and bone marrow toxicity. Chronic inflammation may also lead to the development of second cancer during years after treatment. A number of anti-inflammatory drugs such as nonsteroidal anti-inflammatory agents have been proposed to alleviate chronic inflammatory reactions after radiotherapy or chemotherapy. Curcumin is a well-documented herbal anti-inflammatory agents. Studies have proposed that curcumin can help management of inflammation during and after radiotherapy and chemotherapy. Curcumin targets various inflammatory mediators such as cyclooxygenase-2, inducible nitric oxide synthase, and nuclear factor κB (NF-κB), thereby attenuating the release of proinflammatory and profibrotic cytokines, and suppressing chronic production of free radicals, which culminates in the amelioration of tissue toxicity. Through modulation of NF-κB and its downstream signaling cascade, curcumin can also reduce angiogenesis, tumor growth, and metastasis. Low toxicity of curcumin is linked to its cytoprotective effects in normal tissues. This protective action along with the capacity of this phytochemical to sensitize tumor cells to radiotherapy and chemotherapy makes it a potential candidate for use as an adjuvant in cancer therapy. There is also evidence from clinical trials suggesting the potential utility of curcumin for acute inflammatory reactions during radiotherapy such as dermatitis and mucositis.

Curcumin: A naturally occurring autophagy modulator

Autophagy is a self-degradative process that plays a pivotal role in several medical conditions associated with infection, cancer, neurodegeneration, aging, and metabolic disorders. Its interplay with cancer development and treatment resistance is complicated and paramount for drug design since an autophagic response can lead to tumor suppression by enhancing cellular integrity and tumorigenesis by improving tumor cell survival. In addition, autophagy denotes the cellular ability of adapting to stress though it may end up in apoptosis activation when cells are exposed to a very powerful stress. Induction of autophagy is a therapeutic option in cancer and many anticancer drugs have been developed to this aim. Curcumin as a hydrophobic polyphenol compound extracted from the known spice turmeric has different pharmacological effects in both in vitro and in vivo models. Many reports exist reporting that curcumin is capable of triggering autophagy in several cancer cells. In this review, we will focus on how curcumin can target autophagy in different cellular settings that may extend our understanding of new pharmacological agents to overcome relevant diseases.

Potential Contributions of Antioxidants to Cancer Therapy: Immunomodulation and Radiosensitization

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

Salvianolic acid B protects against myocardial damage caused by nanocarrier TiO2; and synergistic anti-breast carcinoma effect with curcumin via codelivery system of folic acid-targeted and polyethylene glycol-modified TiO2 nanoparticles

Targeted delivery by the folate ligand is an effective way to enhance an anti-breast carcinoma effect, due to its high affinity for the folate receptor, which is overexpressed in many tumor cells. In this study, we firstly synthesized a folic acid (FA)-targeted and polyethylene glycol (PEG)-modified TiO2 nanocarrier. Then, an FA-PEG-TiO2 nanoparticle (NP) codelivery system loaded with curcumin and salvianolic acid B were prepared by emulsion evaporation-solidification at low temperature. The obtained folate-targeted NPs (FA-NPs) showed more cytotoxicity on MCF7 cells and MDA-MB-231 cells than a nontargeted NP group. Apart from a synergistic anti-breast cancer effect with curcumin, salvianolic acid B protects the cardiovascular system from oxidative injury by the TiO2 nanocarrier. With coumarin 6 as a fluorescent probe to observe cellular uptake of NPs, the results of in vitro cellular uptake demonstrated FA-NPs exhibited higher cellular uptake and accumulation in MCF7 cells and MDA-MB-231 cells than nontargeted NPs. Then, in vivo biodistribution of NPs was further qualitatively and quantitatively confirmed by in vivo imaging. More importantly, the animal study further suggested that FA-NPs had significantly stronger antitumor effects via receptor-mediated targeted delivery. Consequently, FA-PEG-TiO2 NPs loaded with curcumin and salvianolic acid B could be a promising drug-delivery system to treat breast cancer.

Detoxification and antioxidant effects of garlic and curcumin in Oreochromis niloticus injected with aflatoxin B₁ with reference to gene expression of glutathione peroxidase (GPx) by RT-PCR

The present study aims to investigate the effects of both garlic and curcumin through evaluating their therapeutic properties as antioxidants on liver and kidney functions, hepatic antioxidants and GPx gene expression against aflatoxicosis of O. niloticus. In total, 180 of tilapia were divided into ten groups; T1 represented the negative control fed on a basal diet, and T2 was injected with a single intraperitoneal (i.p.) dose of AFB1 (6 mg/kg b.w.). Fish in T3-T6 were fed on a basal diet supplemented with both garlic (T3 and T4) and curcumin (T5 and T6) at the two concentrations of 10 and 20 g/kg diet, respectively. Fish in T7-T10 groups were injected with AFB1 and fed on the garlic (T7 and T8) and curcumin (T9 and T10) dietaries. The results showed that AFB1 has significant potency for increasing the activity of plasma AST, ALT, creatinine and uric acid values, and hepatic MDA as well as for reducing the concentrations of plasma TP, AL, GL and hepatic activity of TAC, while AFB1 led to up-regulated GPx gene expression when compared to the control (T1). These harmful effects of AFB1 were alleviated due to the garlic and curcumin dietaries in some studied parameters. Garlic reflected the highest induction of gene expression (T7); however, curcumin showed significant down-regulated (T9). These results concluded that the effects of garlic were better than curcumin at the two concentrations and the low concentration of them is more beneficial than the high concentration when it used against AFB1 in O. niloticus.

Tumour, Oxidative Stress and Host T Cell Response: Cementing the Dominance

Reactive oxygen species (ROS) and free radicals are produced intrinsically during normal cellular metabolic processes or extrinsically due to ionizing radiations, UV rays, xenobiotic insult, etc. ROS are important signal mediators and are used by the immune system to destroy pathogens, but as these are highly reactive, they also have the capacity to cause DNA damage and alter protein and lipid components of a cell. As a result, cells have evolved a tight regulation of internal redox environment that involves a balanced interplay between free radicals produced and quenched by cellular antioxidants and enzyme systems. Any deregulation of this subtle balance can result in oxidative stress that can lead to various pathological conditions including cancer. Oxidative stress can be a cause of neoplasia, or it can be induced by a growing tumour itself. The link existing between oxidative stress and inflammation is also very strong. Suppressed cellular immune system, especially effector T cell system, is a characteristic of tumour-bearing host. Both the direct oxidative stress caused by tumour cell(s) and oxidative stress mediators present in tumour microenvironment play a significant role in the suppression of effector T cell function and induction of T cell death. This review discusses in detail the complex interplay between tumour-stroma-immune system in the light of oxidative stress that dominates every phase of cancer including initiation, progression and establishment. This review also addresses in detail the mechanisms of oxidative stress-induced T cell dysfunction in tumour-bearing host and also briefly points out the possible therapeutic interventions.

Curcumin and tumor immune-editing: resurrecting the immune system

Curcumin has long been known to posses medicinal properties and recent scientific studies have shown its efficacy in treating cancer. Curcumin is now considered to be a promising anti-cancer agent and studies continue on its molecular mechanism of action. Curcumin has been shown to act in a multi-faceted manner by targeting the classical hallmarks of cancer like sustained proliferation, evasion of apoptosis, sustained angiogenesis, insensitivity to growth inhibitors, tissue invasion and metastasis etc. However, one of the emerging hallmarks of cancer is the avoidance of immune system by tumors. Growing tumors adopt several strategies to escape immune surveillance and successfully develop in the body. In this review we highlight the recent studies that show that curcumin also targets this process and helps restore the immune activity against cancer. Curcumin mediates several processes like restoration of CD4⁺/CD8⁺ T cell populations, reversal of type-2 cytokine bias, reduction of Treg cell population and suppression of T cell apoptosis; all these help to resurrect tumor immune surveillance that leads to tumor regression. Thus interaction of curcumin with the immune system is also an important feature of its multi-faceted modes of action against cancer. Finally, we also point out the drawbacks of and difficulties in curcumin administration and indicate the use of nano-formulations of curcumin for better therapeutic efficacy.

Plant natural compounds: targeting pathways of autophagy as anti-cancer therapeutic agents

Natural compounds derived from plant sources are well characterized as possessing a wide variety of remarkable anti-tumour properties, for example modulating programmed cell death, primarily referring to apoptosis, and autophagy. Distinct from apoptosis, autophagy (an evolutionarily conserved, multi-step lysosomal degradation process in which a cell destroys long-lived proteins and damaged organelles) may play crucial regulatory roles in many pathological processes, most notably in cancer. In this review, we focus on highlighting several representative plant natural compounds such as curcumin, resveratrol, paclitaxel, oridonin, quercetin and plant lectin - that may lead to cancer cell death - for regulation of some core autophagic pathways, involved in Ras-Raf signalling, Beclin-1 interactome, BCR-ABL, PI3KCI/Akt/mTOR, FOXO1 signalling and p53. Taken together, these findings would provide a new perspective for exploiting more plant natural compounds as potential novel anti-tumour drugs, by targeting the pathways of autophagy, for future cancer therapeutics.

Curcumin potentiates the antitumor effects of 5-FU in treatment of esophageal squamous carcinoma cells through downregulating the activation of NF-κB signaling pathway in vitro and in vivo

Although constitutive activation of nuclear factor-kappaB (NF-κB) signaling pathway has been reported in multiple different human tumors, the role of NF-κB pathway in esophageal squamous cell carcinoma (ESCC) remains ill-defined. Abundant sources have provided interesting insights into the multiple mechanisms by which curcumin may mediate chemotherapy and chemopreventive effects on cancer. In this study, we first analyzed the status of NF-κB pathway in the two ESCC cell lines Eca109 and EC9706, and then further investigated whether curcumin alone or in combination with 5-fluorouracil (5-FU) could modulate NF-κB pathway in vitro and in vivo. The results showed that NF-κB signaling pathway was constitutively activated in the ESCC cell lines. Curcumin suppressed the activation of NF-κB via the inhibition of IκBα phosphorylation, and downregulated the expressions of Bcl-2 and CyclinD1 in ESCC cell lines. Curcumin combined with 5-FU led to the lower cell viability and higher apoptosis than 5-FU treated alone. In a human ESCC xenograft model, curcumin or 5-FU alone reduced the tumor volume, but their combination had the strongest anticancer effects. Besides, curcumin could also inhibit NF-κB signaling pathway through downregulation of the IκBα phosphorylation and induction of cell apoptosis in vivo. Overall, our results indicated that constitutively activated NF-κB signaling pathway exists in the two ESCC cells and the chemopreventive effects of curcumin were associated with downregulation of NF-κB signaling pathway and its downstream genes.

Curcumin enhances the efficacy of chemotherapy by tailoring p65NFκB-p300 cross-talk in favor of p53-p300 in breast cancer

Breast cancer cells often develop multiple mechanisms of drug resistance during tumor progression, which is the major reason for the failure of breast cancer therapy. High constitutive activation of NFκB has been found in different cancers, creating an environment conducive for chemotherapeutic resistance. Here we report that doxorubicin-induced SMAR1-dependent transcriptional repression and SMAR1-independent degradation of IkBα resulted in nuclear translocation of p65NFκB and its association with p300 histone acetylase and subsequent transcription of Bcl-2 to impart protective response in drug-resistant cells. Consistently SMAR1-silenced drug-resistant cells exhibited IkBα-mediated inhibition of p65NFκB and induction of p53-dependent apoptosis. Interestingly, curcumin pretreatment of drug-resistant cells alleviated SMAR1-mediated p65NFκB activation and hence restored doxorubicin sensitivity. Under such anti-survival condition, induction of p53-p300 cross-talk enhanced the transcriptional activity of p53 and intrinsic death cascade. Importantly, promyelocyte leukemia-mediated SMAR1 sequestration that relieved the repression of apoptosis-inducing genes was indispensable for such chemo-sensitizing ability of curcumin. A simultaneous decrease in drug-induced systemic toxicity by curcumin might also have enhanced the efficacy of doxorubicin by improving the intrinsic defense machineries of the tumor-bearer. Overall, the findings of this preclinical study clearly demonstrate the effectiveness of curcumin to combat doxorubicin-resistance. We, therefore, suggest curcumin as a potent chemo-sensitizer to improve the therapeutic index of this widely used anti-cancer drug. Taken together, these results suggest that curcumin can be developed into an adjuvant chemotherapeutic drug.

A Pilot Cross-Over Study to Evaluate Human Oral Bioavailability of BCM-95CG (Biocurcumax), A Novel Bioenhanced Preparation of Curcumin

Curcumin, the bioactive component of turmeric, Curcuma longa has an exceptionally wide spectrum of activities including antioxidant, anti-inflammatory and anti-cancer properties, and is currently under different phases of clinical trials for various types of soft tissue cancers. However, although in vitro and animal studies have shown anticancer activities of curcumin for virtually all types of human cancers, its poor bioavailability in the human body has severely limited its application to these diseases. Methods to increase its oral bioavailability are a subject of intense current research. Reconstituting curcumin with the non-curcuminoid components of turmeric has been found to increase the bioavailability substantially. In the present clinical study to determine the bioavailability of curcuminoids, a patented formulation, BCM-95^®CG was tested on human volunteer group. Normal curcumin was used in the control group. Curcumin content in blood was estimated at periodical intervals. After a washout period of two weeks the control group and drug group were crossed over BCM-95^®CG and curcumin, respectively. It was also compared with a combination of curcumin-lecithin-piperine which was earlier shown to provide enhanced bioavailability. The results of the study indicate that the relative bioavailability of BCM-95^®CG (Biocurcumax™) was about 6.93-fold compared to normal curcumin and about 6.3-fold compared to curcumin-lecithin-piperine formula. BCM-95^®CG thus, has potential for widespread application for various chronic diseases.

Curcumin enhanced adriamycin-induced human liver-derived Hepatoma G2 cell death through activation of mitochondria-mediated apoptosis and autophagy

Hepatocellular carcinoma (HCC) is the fifth most common cancer and the third leading cancer killer in the world. Adriamycin (ADM) is a widely used anti-cancer drug. However, the efficacy is low since high dose of ADM causes toxicity to normal tissues. Curcumin, derived from turmeric (Curcumin longa), has shown its therapeutic potential against HCC. Here, we aim to investigate the effects of curcumin combined with ADM on human liver-derived Hepatoma G2 (HepG2) cell death. We found that combination treatment of curcumin with ADM significantly decreased the number of viable cells as compared to single agent treatment. Hoechst staining demonstrated that apoptotic cell death occurred upon curcumin and ADM treatment. The decreased Bcl-2/Bax protein ratio and the activation of caspase-3 were also detected. In addition, curcumin plus ADM led to mitochondrial fragmentation, the reduction of mitochondrial membrane potential, as well as the activation of autophagy. These findings suggest the combined treatment of curcumin with ADM might be an optional chemotherapeutic method for HCC.

Anticancer and carcinogenic properties of curcumin: considerations for its clinical development as a cancer chemopreventive and chemotherapeutic agent

A growing body of research suggests that curcumin, the major active constituent of the dietary spice turmeric, has potential for the prevention and therapy of cancer. Preclinical data have shown that curcumin can both inhibit the formation of tumors in animal models of carcinogenesis and act on a variety of molecular targets involved in cancer development. In vitro studies have demonstrated that curcumin is an efficient inducer of apoptosis and some degree of selectivity for cancer cells has been observed. Clinical trials have revealed that curcumin is well tolerated and may produce antitumor effects in people with precancerous lesions or who are at a high risk for developing cancer. This seems to indicate that curcumin is a pharmacologically safe agent that may be used in cancer chemoprevention and therapy. Both in vitro and in vivo studies have shown, however, that curcumin may produce toxic and carcinogenic effects under specific conditions. Curcumin may also alter the effectiveness of radiotherapy and chemotherapy. This review article analyzes the in vitro and in vivo cancer-related activities of curcumin and discusses that they are linked to its known antioxidant and pro-oxidant properties. Several considerations that may help develop curcumin as an anticancer agent are also discussed.

Anti cancer effects of curcumin: cycle of life and death

Increasing knowledge on the cell cycle deregulations in cancers has promoted the introduction of phytochemicals, which can either modulate signaling pathways leading to cell cycle regulation or directly alter cell cycle regulatory molecules, in cancer therapy. Most human malignancies are driven by chromosomal translocations or other genetic alterations that directly affect the function of critical cell cycle proteins such as cyclins as well as tumor suppressors, e.g., p53. In this respect, cell cycle regulation and its modulation by curcumin are gaining widespread attention in recent years. Extensive research has addressed the chemotherapeutic potential of curcumin (diferuloylmethane), a relatively non-toxic plant derived polyphenol. The mechanisms implicated are diverse and appear to involve a combination of cell signaling pathways at multiple levels. In the present review we discuss how alterations in the cell cycle control contribute to the malignant transformation and provide an overview of how curcumin targets cell cycle regulatory molecules to assert anti-proliferative and/or apoptotic effects in cancer cells. The purpose of the current article is to present an appraisal of the current level of knowledge regarding the potential of curcumin as an agent for the chemoprevention of cancer via an understanding of its mechanism of action at the level of cell cycle regulation. Taken together, this review seeks to summarize the unique properties of curcumin that may be exploited for successful clinical cancer prevention.

Immunomodulation by curcumin

Turmeric, the bright yellow spice extracted from the tuberous rhizome of the plant Curcuma longa, has been used in traditional Indian and Chinese systems of medicine for centuries to treat a variety of ailments, including jaundice and hepatic disorders, rheumatism, anorexia, diabetic wounds, and menstrual difficulties. Most of the medicinal effects of turmeric have been attributed to curcumin, the principal curcumanoid found in turmeric. Recent evidence that curcumin exhibits strong anti-inflammatory and antioxidant activities and modulates the expression of transcription factors, cell cycle proteins, and signal transducing kinases has prompted the mechanism-based studies on the potential of curcumin to primarily prevent and treat cancer and inflammatory diseases. Little work has been done to study the effect of curcumin on the development of immune responses. This review discusses current knowledge on the immunomodulatory effects of curcumin on various facets of the immune response, including its effect on lymphoid cell populations, antigen presentation, humoral and cell-mediated immunity, and cytokine production.

Tumor-Induced Oxidative Stress Perturbs Nuclear Factor-κB Activity-Augmenting Tumor Necrosis Factor-α–Mediated T-Cell Death: Protection by Curcumin

Cancer patients often exhibit loss of proper cell-mediated immunity and reduced effector T-cell population in the circulation. Thymus is a major site of T-cell maturation, and tumors induce thymic atrophy to evade cellular immune response. Here, we report severe thymic hypocellularity along with decreased thymic integrity in tumor bearer. In an effort to delineate the mechanisms behind such thymic atrophy, we observed that tumor-induced oxidative stress played a critical role, as it perturbed nuclear factor-kappaB (NF-kappaB) activity. Tumor-induced oxidative stress increased cytosolic IkappaBalpha retention and inhibited NF-kappaB nuclear translocation in thymic T cells. These NF-kappaB-perturbed cells became vulnerable to tumor-secreted tumor necrosis factor (TNF)-alpha (TNF-alpha)-mediated apoptosis through the activation of TNF receptor-associated protein death domain-associated Fas-associated protein death domain and caspase-8. Interestingly, TNF-alpha-depleted tumor supernatants, either by antibody neutralization or by TNF-alpha-small interfering RNA transfection of tumor cells, were unable to kill T cell effectively. When T cells were overexpressed with NF-kappaB, the cells became resistant to tumor-induced apoptosis. In contrast, when degradation-defective IkappaBalpha (IkappaBalpha super-repressor) was introduced into T cells, the cells became more vulnerable, indicating that inhibition of NF-kappaB is the reason behind such tumor/TNF-alpha-mediated apoptosis. Curcumin could prevent tumor-induced thymic atrophy by restoring the activity of NF-kappaB. Further investigations suggest that neutralization of tumor-induced oxidative stress and restoration of NF-kappaB activity along with the reeducation of the TNF-alpha signaling pathway can be the mechanism behind curcumin-mediated thymic protection. Thus, our results suggest that unlike many other anticancer agents, curcumin is not only devoid of immunosuppressive effects but also acts as immunorestorer in tumor-bearing host.