Myelopotentiating effect of curcumin in tumor-bearing host: Role of bone marrow resident macrophages

Orchestral role of lipid metabolic reprogramming in T-cell malignancy

The immune function of normal T cells partially depends on the maneuvering of lipid metabolism through various stages and subsets. Interestingly, T-cell malignancies also reprogram their lipid metabolism to fulfill bioenergetic demand for rapid division. The rewiring of lipid metabolism in T-cell malignancies not only provides survival benefits but also contributes to their stemness, invasion, metastasis, and angiogenesis. Owing to distinctive lipid metabolic programming in T-cell cancer, quantitative, qualitative, and spatial enrichment of specific lipid molecules occur. The formation of lipid rafts rich in cholesterol confers physical strength and sustains survival signals. The accumulation of lipids through de novo synthesis and uptake of free lipids contribute to the bioenergetic reserve required for robust demand during migration and metastasis. Lipid storage in cells leads to the formation of specialized structures known as lipid droplets. The inimitable changes in fatty acid synthesis (FAS) and fatty acid oxidation (FAO) are in dynamic balance in T-cell malignancies. FAO fuels the molecular pumps causing chemoresistance, while FAS offers structural and signaling lipids for rapid division. Lipid metabolism in T-cell cancer provides molecules having immunosuppressive abilities. Moreover, the distinctive composition of membrane lipids has implications for immune evasion by malignant cells of T-cell origin. Lipid droplets and lipid rafts are contributors to maintaining hallmarks of cancer in malignancies of T cells. In preclinical settings, molecular targeting of lipid metabolism in T-cell cancer potentiates the antitumor immunity and chemotherapeutic response. Thus, the direct and adjunct benefit of lipid metabolic targeting is expected to improve the clinical management of T-cell malignancies.

Counteracting Action of Curcumin on High Glucose-Induced Chemoresistance in Hepatic Carcinoma Cells

Along with direct anticancer activity, curcumin hinders the onset of chemoresistance. Among many, high glucose condition is a key driving factor for chemoresistance. However, the ability of curcumin remains unexplored against high glucose-induced chemoresistance. Moreover, chemoresistance is major hindrance in effective clinical management of liver cancer. Using hepatic carcinoma HepG2 cells, the present investigation demonstrates that high glucose induces chemoresistance, which is averted by the simultaneous presence of curcumin. Curcumin obviated the hyperglycemia-induced modulations like elevated glucose consumption, lactate production, and extracellular acidification, and diminished nitric oxide and reactive oxygen species (ROS) production. Modulated molecular regulators are suggested to play a crucial role as curcumin pretreatment also prevented the onset of chemoresistance by high glucose. High glucose instigated suppression in the intracellular accumulation of anticancer drug doxorubicin and drug-induced chromatin compactness along with declined expression of drug efflux pump MDR-1 and transcription factors and signal transducers governing the survival, aggressiveness, and apoptotic cell death (p53, HIF-1α, mTOR, MYC, STAT3). Curcumin alleviated the suppression of drug retention and nuclear condensation along with hindering the high glucose-induced alterations in transcription factors and signal transducers. High glucose-driven resistance in cancer cells was associated with elevated expression of metabolic enzymes HKII, PFK1, GAPDH, PKM2, LDH-A, IDH3A, and FASN. Metabolite transporters and receptors (GLUT-1, MCT-1, MCT-4, and HCAR-1) were also found upregulated in high glucose exposed HepG2 cells. Curcumin inhibited the elevated expression of these enzymes, transporters, and receptors in cancer cells. Curcumin also uplifted the SDH expression, which was inhibited in high glucose condition. Taken together, the findings of the present investigation first time demonstrate the ability of curcumin against high glucose-induced chemoresistance, along with its molecular mechanism. This will have implication in therapeutic management of malignancies in diabetic conditions.

Antiviral and immunomodulatory activity of curcumin: A case for prophylactic therapy for COVID-19

Coronavirus disease-19 (COVID-19), a devastating respiratory illness caused by SARS-associated coronavirus-2 (SARS-CoV-2), has already affected over 64 million people and caused 1.48 million deaths, just 12 months from the first diagnosis. COVID-19 patients develop serious complications, including severe pneumonia, acute respiratory distress syndrome (ARDS), and or multiorgan failure due to exaggerated host immune response following infection. Currently, drugs that were effective against SARS-CoV are being repurposed for SARS-CoV-2. During this public health emergency, food nutraceuticals could be promising prophylactic therapeutics for COVID-19. Curcumin, a bioactive compound in turmeric, exerts diverse pharmacological activities and is widely used in foods and traditional medicines. This review presents several lines of evidence, which suggest curcumin as a promising prophylactic, therapeutic candidate for COVID-19. First, curcumin exerts antiviral activity against many types of enveloped viruses, including SARS-CoV-2, by multiple mechanisms: direct interaction with viral membrane proteins; disruption of the viral envelope; inhibition of viral proteases; induce host antiviral responses. Second, curcumin protects from lethal pneumonia and ARDS via targeting NF-κB, inflammasome, IL-6 trans signal, and HMGB1 pathways. Third, curcumin is safe and well-tolerated in both healthy and diseased human subjects. In conclusion, accumulated evidence indicates that curcumin may be a potential prophylactic therapeutic for COVID-19 in the clinic and public health settings.

Curcumin, a traditional spice component, can hold the promise against COVID-19?

The severity of the recent pandemic and the absence of any specific medication impelled the identification of existing drugs with potential in the treatment of Coronavirus disease-2019 (COVID-19), caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). Curcumin, known for its pharmacological abilities especially as an anti-inflammatory agent, can be hypothesized as a potential candidate in the therapeutic regimen. COVID-19 has an assorted range of pathophysiological consequences, including pulmonary damage, elevated inflammatory response, coagulopathy, and multi-organ damage. This review summarizes the several evidences for the pharmacological benefits of curcumin in COVID-19-associated clinical manifestations. Curcumin can be appraised to hinder cellular entry, replication of SARS-CoV-2, and to prevent and repair COVID-19-associated damage of pneumocytes, renal cells, cardiomyocytes, hematopoietic stem cells, etc. The modulation and protective effect of curcumin on cytokine storm-related disorders are also discussed. Collectively, this review provides grounds for its clinical evaluation in the therapeutic management of SARS-CoV-2 infection.

Curcumin circumvent lactate-induced chemoresistance in hepatic cancer cells through modulation of hydroxycarboxylic acid receptor-1

Curcumin has been demonstrated to affect the chemoresistance in cancer cells of various origins. However, its ability to modulate lactate-induced chemoresistance remains unclear. The Present investigation demonstrates that curcumin inhibits the survival of HepG2 and HuT78 cells and can modulate chemo-susceptibility of HepG2 cells. Experimental simulation of simultaneous and pre-treatment suggest cooperatively between curcumin and anticancer drugs as well as the modulation of molecular regulators. Inhibition of glucose consumption, lactate production, extracellular acidity and augmented level of Nitric oxide were observed. DAPI staining revealed hyper condensation of chromatin in curcumin-treated HepG2 cells. Curcumin also diminished the lactate-induced chemoresistance against doxorubicin in hepatic cancer cells along with down regulation of lactate receptor (hydroxycarboxylic acid receptor-1; HCAR-1/GPR81). Alteration of the extracellular milieu along with inhibited expression of genes (hif-1α, ldh-a, mct-1, mdr-1 and stat-3) and proteins (HIF-1α and HCAR-1) are indicated to be involved in curcumin-induced reversal of chemoresistance in HepG2 cells. Findings of present investigation contribute to knowledge of curcumin mediated chemosensitization and its mechanism.

Antimetabolic Agent 3-Bromopyruvate Exerts Myelopotentiating Action in a Murine Host Bearing a Progressively Growing Ascitic Thymoma

Tumor growth and its chemotherapeutic regimens manifest myelosuppression, which is one of the possible causes underlying the limited success of immunotherapeutic anticancer strategies. Hence, approaches are being designed to develop safer therapeutic regimens that may have minimal damaging action on the process of myelopoiesis. 3-Bromopyruvate (3-BP) is a highly potent antimetabolic agent displaying a broad spectrum antineoplastic activity. However, 3-BP has not been investigated for its effect on the process of myelopoiesis in a tumor-bearing host. Hence, in this investigation, we studied the myelopoietic effect of in vivo administration of 3-BP to a murine host bearing a progressively growing ascitic thymoma designated as Dalton's lymphoma (DL). 3-BP administration to the DL-bearing mice resulted in a myelopotentiating action, reflected by an elevated count of bone marrow cells (BMC) accompanied by augmented proliferative ability and a declined induction of apoptosis. The BMC of 3-BP-administered mice displayed enhanced responsiveness to macrophage colony-stimulating factor for colony-forming ability of myeloid lineage along with an enhanced differentiation of F4/80⁺ bone marrow-derived macrophages (BMDM). BMDM differentiated from the BMC of 3-BP-administered DL-bearing mice showed an augmented response to lipopolysaccharide and interferon-γ for activation, displaying an augmented tumor cytotoxicity, expression of cytokines, reactive oxygen species, nitric oxide, CD11c, TLR-4, and HSP70. These features are indicative of the differentiation of M1 subtype of macrophages. Thus, this study demonstrates the myelopotentiating action of 3-BP, indicating its hematopoietic safety and potential for reinforcing the differentiation of macrophages in a tumor-bearing host.

Protective and recuperative effects of 3-bromopyruvate on immunological, hepatic and renal homeostasis in a murine host bearing ascitic lymphoma: Implication of niche dependent differential roles of macrophages

3-bromopyruvate (3-BP) possesses promising antineoplastic potential, however, its effects on immunological homeostasis vis a vis hepatic and renal functions in a tumor bearing host remain unclear. Therefore, the effect of 3-BP administration to a murine host bearing a progressively growing tumor of thymoma origin, designated as Dalton's lymphoma (DL), on immunological, renal and hepatic homeostasis was investigated. Administration of 3-BP (4 mg/kg) to the tumor bearing host reversed tumor growth associated thymic atrophy and splenomegaly, accompanied by altered cell survival and repertoire of splenic, bone marrow and tumor associated macrophages (TAM). TAM displayed augmented phagocytic, tumoricidal activities and production of IL-1 and TNF-α. 3-BP-induced activation of TAM was of indirect nature, mediated by IFN-γ. Blood count of T lymphocytes (CD4⁺ & CD8⁺) and NK cells showed a rise in 3-BP administered tumor bearing mice. Moreover, 3-BP administration triggered modulation of immunomodulatory cytokines in serum along with refurbished hepatic and renal functions. The study indicates the role of altered cytokines balance, site specific differential macrophage functions and myelopoiesis in restoration of lymphoid organ homeostasis in 3-BP administered tumor bearing host. These observations will have long lasting impact in understanding of alternate mechanisms underlying the antitumor action of 3-BP accompanying appraisal of safety issues for optimizing its antineoplastic actions.

Cucurmin, anticancer, & antitumor perspectives: A comprehensive review

Cucurmin, a naturally yellow component isolated from turmeric, ability to prevent various life-style related disorders. The current review article mainly emphasizes on different anticancer perspectives of cucurmin, i.e., colon, cervical, uterine, ovarian, prostate head and neck, breast, pulmonary, stomach and gastric, pancreatic, bladder oral, oesophageal, and bone cancer. It holds a mixture of strong bioactive molecule known as cucurminoids that has ability to reduce cancer/tumor at initial, promotion and progression stages of tumor development. In particular, these compounds block several enzymes required for the growth of tumors and may therefore involve in tumor treatments. Moreover, it modulates an array of cellular progressions, i.e., nitric oxide synthetase activity, protein kinase C activity, epidermal growth factor (EGF) receptor intrinsic kinase activity, nuclear factor kappa (NF-kB) activity, inhibiting lipid peroxidation and production of reactive oxygen species. However, current manuscript summarizes most of the recent investigations of cucurmin but still further research should be conducted to explore the role of curcumin to mitigate various cancers.

Evaluation of intracavitary administration of curcumin for the treatment of sarcomatoid mesothelioma

A rat model of sarcomatoid mesothelioma, mimicking some of the worst clinical conditions encountered, was established to evaluate the therapeutic potential of intracavitary curcumin administration.

The M5-T1 cell line, selected from a collection established from F344 rats induced with asbestos, produces tumors within three weeks, with extended metastasis in normal tissues, after intraperitoneal inoculation in syngeneic rats. The optimal concentration/time conditions for killing M5-T1 cells with curcumin were first determined in vitro. Secondly, the potential of intraperitoneal curcumin administration to kill tumor cells in vivo was evaluated in tumor-bearing rats, in comparison with a reference epigenetic drug, SAHA.

Both agents administered at days 21 and 26 after tumor challenge produced necrosis within the solid tumors at day 28. However, tumor tissue necrosis induced with curcumin was much more extensive than with SAHA, and was characterized by infiltration with mononuclear phagocytic cells. In contrast, tumor tissue treated with SAHA contained foci of resistant cells and was infiltrated by many isolated CD8+ cells. The treatment of tumor-bearing rats with 1.5 mg/kg curcumin on days 7, 9, 11 and 14 after tumor challenge dramatically reduced the mean total tumor mass at day 16. Clusters of CD8+ T lymphocytes were observed at the periphery of small residual tumor masses in the peritoneal cavity, which presented a significant reduction in mitotic index, IL6 and vimentin expression compared with tumors in untreated rats.

These data open up interesting new prospects for the therapy of sarcomatoid mesothelioma with curcumin and its derivatives.

Targeting monocarboxylate transporter by α-cyano-4-hydroxycinnamate modulates apoptosis and cisplatin resistance of Colo205 cells: implication of altered cell survival regulation

The present investigation was undertaken to study the effect of in vitro exposure of Colo205, colonadenocarcinoma cells, to monocarboxylate transporter inhibitor α-cyano-4-hydroxycinnamate (αCHC) on cell survival and evolution of resistance to chemotherapeutic drug cisplatin. αCHC-treated Colo205 cells showed inhibition of survival accompanied by an augmented induction of apoptosis. Changes in cell survival properties were associated with alterations in lactate efflux, pH homeostasis, expression of glucose transporters, glucose uptake, HIF-1α, generation of nitric oxide, expression pattern of some key cell survival regulatory molecules: Bcl2, Bax, active caspase-3 and p53. Pretreatment of Colo205 cells with αCHC also altered their susceptibility to the cytotoxicity of cisplatin accompanied by altered expression of multidrug resistance regulating MDR1 and MRP1 genes. This study for the first time deciphers some of the key molecular events underlying modulation of cell survival of cancer cells of colorectal origin by αCHC and its contribution to chemosensitization against cisplatin. Thus these findings will be of immense help in further research for optimizing the use of αCHC for improving the chemotherapeutic efficacy of anticancer drugs like cisplatin.

Myelopoietic efficacy of orlistat in murine hosts bearing T cell lymphoma: implication in macrophage differentiation and activation

Orlistat, an inhibitor of fatty acid synthase (FASN), acts as an antitumor agent by blocking de novo fatty acid synthesis of tumor cells. Although, myelopoiesis also depends on de novo fatty acid synthesis, the effect of orlistat on differentiation of macrophages, which play a central role in host’s antitumor defence, remains unexplored in a tumor-bearing host. Therefore, the present investigation was undertaken to examine the effect of orlistat administration on macrophage differentiation in a T cell lymphoma bearing host. Administration of orlistat (240 mg/kg/day/mice) to tumor-bearing mice resulted in a decline of tumor load accompanied by an augmentation of bone marrow cellularity and survival of bone marrow cells (BMC). The expression of apoptosis regulatory caspase-3, Bax and Bcl2 was modulated in the BMC of orlistat-administered tumor-bearing mice. Orlistat administration also resulted in an increase in serum level of IFN-γ along with decreased TGF-β and IL-10. BMC of orlistat-administered tumor-bearing mice showed augmented differentiation into macrophages accompanied by enhanced expression of macrophage colony stimulating factor (M-CSF) and its receptor (M-CSFR). The macrophages differentiated from BMC of orlistat-administered mice showed characteristic features of M₁ macrophage phenotype confirmed by expression of CD11c, TLR-2, generation of reactive oxygen species, phagocytosis, tumor cell cytotoxicity, production of IL-1,TNF-α and nitric oxide. These novel findings indicate that orlistat could be useful to support myelopoesis in a tumor-bearing host.

Antitumor and chemosensitizing action of dichloroacetate implicates modulation of tumor microenvironment: a role of reorganized glucose metabolism, cell survival regulation and macrophage differentiation

Targeting of tumor metabolism is emerging as a novel therapeutic strategy against cancer. Dichloroacetate (DCA), an inhibitor of pyruvate dehydrogenase kinase (PDK), has been shown to exert a potent tumoricidal action against a variety of tumor cells. The main mode of its antineoplastic action implicates a shift of glycolysis to oxidative metabolism of glucose, leading to generation of cytotoxic reactive oxygen intermediates. However, the effect of DCA on tumor microenvironment, which in turn regulates tumor cell survival; remains speculative to a large extent. It is also unclear if DCA can exert any modulatory effect on the process of hematopoiesis, which is in a compromised state in tumor-bearing hosts undergoing chemotherapy. In view of these lacunas, the present study was undertaken to investigate the so far unexplored aspects with respect to the molecular mechanisms of DCA-dependent tumor growth retardation and chemosensitization. BALB/c mice were transplanted with Dalton's lymphoma (DL) cells, a T cell lymphoma of spontaneous origin, followed by administration of DCA with or without cisplatin. DCA-dependent tumor regression and chemosensitization to cisplatin was found to be associated with altered repertoire of key cell survival regulatory molecules, modulated glucose metabolism, accompanying reconstituted tumor microenvironment with respect to pH homeostasis, cytokine balance and alternatively activated TAM. Moreover, DCA administration also led to an alteration in the MDR phenotype of tumor cells and myelopoietic differentiation of macrophages. The findings of this study shed a new light with respect to some of the novel mechanisms underlying the antitumor action of DCA and thus may have immense clinical applications.