Nimbolide induces cell death in T lymphoma cells: Implication of altered apoptosis and glucose metabolism

Nimbolide: A Potential Phytochemical Agent in Multimodal Pancreatic Cancer Therapies

A significant contributor to cancer-related death, pancreatic cancer (PC) has a terrible prognosis in general that has not altered over many years. Currently, it is extremely difficult to prevent disease or discover it early enough to initiate treatment. PC is a challenging malignancy to treat, and several major impediments significantly impact the effectiveness of its treatment. These obstacles primarily include chemoresistance, drug toxicity, and limited drug bioavailability. Phytochemicals can be used as an alternative to chemotherapeutic drugs, or they can augment the anticancer properties of the chemotherapeutic agents. Nimbolide (NL) is a prominent limonoid compound found in Azadirachta indica, and has garnered substantial attention as a phytochemical with anticancer potential. It has powerful antiproliferative effects on a variety of cancer cell lines and is effective as a chemotherapeutic in preclinical studies. The primary modes of action of NL include suppression of metastasis and angiogenesis, activation of apoptosis, anti-proliferation, and control of enzymes that metabolize carcinogens. Despite numerous pharmacodynamic (PD) investigations, NL is still in the early stages of the drug development process because no comprehensive pharmacokinetic studies or long-term toxicity studies. Preclinical and toxicological assessments should be conducted to establish an appropriate dosage range, ensuring the safety of NL for its application in initial human clinical trials. This review endeavors to provide a comprehensive summary of the current developmental stage of NL along with nanoparticles as a principal candidate for therapeutic purposes in PC.

Insights into Nimbolide molecular crosstalk and its anticancer properties

Nimbolide, one of the main ingredients constituent of Azadirachta indica (neem) leaf extract, has garnered attention for its potential as an anticancer agent. Its efficacy against various cancers and chemopreventive action has been demonstrated through numerous in vivo and in vitro studies. This updated review aims to comprehensively explore the chemopreventive and anticancer properties of nimbolide, emphasizing its molecular mechanisms of action and potential therapeutic applications in oncology. The review synthesizes evidence from various studies that examine nimbolide's roles in apoptosis induction, anti-proliferation, cell death, metastasis inhibition, angiogenesis suppression, and modulation of carcinogen-metabolizing enzymes. Nimbolide exhibits multifaceted anticancer activities, including the modulation of multiple cell signaling pathways related to inflammation, invasion, survival, growth, metastasis, and angiogenesis. However, its pharmacological development is still in the early stages, mainly due to limited pharmacokinetic and comprehensive long-term toxicological studies. Nimbolide shows promising anticancer and chemopreventive properties, but there is need for systematic preclinical pharmacokinetic and toxicological research. Such studies are essential for establishing safe dosage ranges for first-in-human clinical trials and further advancing nimbolide's development as a therapeutic agent against various cancers. The review highlights the potential of nimbolide in cancer treatment and underscores the importance of rigorous preclinical evaluation to realize its full therapeutic potential.

Blockade of phosphodiesterase 5 by sildenafil reduces tumor growth and potentiates tumor-killing ability of cisplatin in vivo against T cell lymphoma: Implication of modulated apoptosis, reactive oxygen species homeostasis, glucose metabolism, and pH regulation

In the past years, PDE5 has emerged as a promising therapeutic target for many cancers due to its highly upregulated expression. Interestingly, a recent in vitro study by our group has shown the antitumor and chemopotentiating action of sildenafil against T cell lymphoma. Our study showed that lower doses of sildenafil (50 μM) and cisplatin (0.5 μg/mL) exhibited 4% and 23% cytotoxicity against HuT78 cells, respectively, which was dramatically increased up to 50% when treated with both. Hence, the present study was designed to evaluate the antitumor and chemo-potentiating action of sildenafil in a murine model of T cell lymphoma (popularly called as Dalton's lymphoma [DL]). In the present study, DL-bearing mice were administered with vehicle (PBS), sildenafil (5 mg/kg bw), cisplatin (5 mg/kg bw), and sildenafil and cisplatin followed by evaluation of their impact on tumor growth by analyzing various parameters. The apoptosis was assessed by Wright-Giemsa, annexin-V, and DAPI staining. Reactive oxygen species (ROS) level was examined through DCFDA staining. The expression of genes and proteins were estimated by RT-PCR and Western blotting, respectively. The experimental findings of the study demonstrate for the first time that sildenafil inhibits tumor growth and potentiates tumor inhibitory ability of cisplatin by altering apoptosis, glycolysis, ROS homeostasis, and pH regulation in T cell lymphoma-carrying host. In addition, our investigation also showed amelioration of tumor-induced liver and kidney damage by sildenafil. Overall, the experimental data of our study strongly advocate the use and repurposing of SDF in designing promising chemotherapeutic regimens against malignancies of T cells.

Enhanced anti-cancer potency of sustainably synthesized anisotropic silver nanoparticles as compared with L-asparaginase

Acute lymphoblastic leukemia (ALL), a hematologic cancer that involves the production of abnormal lymphoid precursor cells, primarily affects children aged 2 to 10 years. The bacterial enzyme L-asparaginase produced from Escherichia coli is utilised as first-line therapy, despite the fact that 30 % of patients have a treatment-limiting hypersensitivity reaction. The current study elucidates the biosynthesis of extremely stable, water-dispersible, anisotropic silver nanoparticles (ANI Ag NPs) at room temperature and investigation of its anti-tumor potency in comparison to L-asparaginase. The optical, morphological, compositional, and structural properties of synthesized nanoparticles were evaluated using UV-Vis-NIR spectroscopy, Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy, and X-ray Diffractometer. The UV-Vis-NIR spectra revealed the typical Surface Plasmon Resonance (SPR) at 423 nm along with additional NIR absorption at 962 nm and 1153 nm, while TEM images show different shapes and sizes of Ag nanoparticles ranging from 6.81 nm to 46 nm, together confirming their anisotropic nature. Further, the MTT assay demonstrated promising anticancer effects of ANI Ag NPs with an IC50 value of ∼7 μg/mL against HuT-78 cells. These sustainable anisotropic silver nanoparticles exhibited approximately four times better cytotoxic ability (at and above 10 μg/mL concentrations) than L-asparaginase against HuT-78 cells (a human T lymphoma cell line). Apoptosis analysis by Wright-Geimsa, Annexin-V, and DAPI staining indicated the role of apoptosis in ANI Ag NPs-mediated cell death. The measurement of NO, and Bcl2 and cleaved caspase-3 levels by colorimetric method and immunoblotting, respectively suggested their involvement in ANI Ag NPs-elicited apoptosis. The findings indicate that the biogenic approach proposed herein holds tremendous promise for the rapid and straightforward design of novel multifunctional nanoparticles for the treatment of T cell malignancies.

The antagonist of β-adrenergic receptor propranolol inhibits T cell lymphoma growth and enhances antitumor efficacy of cisplatin in vivo: A role of modulated apoptosis, glucose metabolism, pH regulation, and antitumor immune response

Accumulating evidence has shown a vital role of stress-regulatory hormones, including epinephrine, in the progression of numerous cancers, including T cell lymphoma. Further, the antitumor and chemosensitizing potential of propranolol, an inexpensive β-adrenergic receptor antagonist has also been reported against breast, colon, ovarian, and pancreatic cancers. However, in vivo antitumor and chemopotentiating activity of propranolol have not yet been examined against malignancies of hematological origin, including T cell lymphoma. Therefore, the present study is designed to evaluate the antitumor and chemopotentiating action of propranolol in a T cell lymphoma murine model. In this study, T cell lymphoma-bearing mice were treated with vehicle alone (PBS) or containing propranolol followed by administration of with or without cisplatin. The progression of the tumor was assessed along with analysis of tumor cell apoptosis, glucose metabolism, pH regulation, and antitumor immune response. The apoptosis was estimated by cellular and nuclear morphology analysis through Wright-Giemsa, annexin-V, and DAPI staining. ELISA was used to detect the epinephrine level in serum. The glucose, lactate, and NO levels were measured in the tumor ascitic fluid by calorimetric methods. RT-PCR and Western blot were used to assess the levels of various crucial regulators at gene and protein levels, respectively. Our results showed that propranolol exerts antitumor as well as chemopotentiating ability in DL-bearing mice by altering apoptosis, glycolysis, acidification of TME, and immunosuppression.

Chemotherapy-Mediated Neuronal Aberration

Chemotherapy is a life-sustaining therapeutic option for cancer patients. Despite the advancement of several modern therapies, such as immunotherapy, gene therapy, etc., chemotherapy remains the first-line therapy for most cancer patients. Along with its anti-cancerous effect, chemotherapy exhibits several detrimental consequences that restrict its efficacy and long-term utilization. Moreover, it effectively hampers the quality of life of cancer patients. Cancer patients receiving chemotherapeutic drugs suffer from neurological dysfunction, referred to as chemobrain, that includes cognitive and memory dysfunction and deficits in learning, reasoning, and concentration ability. Chemotherapy exhibits neurotoxicity by damaging the DNA in neurons by interfering with the DNA repair system and antioxidant machinery. In addition, chemotherapy also provokes inflammation by inducing the release of various pro-inflammatory cytokines, including NF-kB, IL-1β, IL-6, and TNF-α. The chemotherapy-mediated inflammation contributes to chemobrain in cancer patients. These inflammatory cytokines modulate several growth signaling pathways and reactive oxygen species homeostasis leading to systemic inflammation in the body. This review is an effort to summarize the available information which discusses the role of chemotherapy-induced inflammation in chemobrain and how it impacts different aspects of therapeutic outcome and the overall quality of life of the patient. Further, this article also discusses the potential of herbal-based remedies to overcome chemotherapy-mediated neuronal toxicity as well as to improve the quality of life of cancer patients.

Ethyl Acetate Extract of Colletotrichum gloeosporioides Promotes Cytotoxicity and Apoptosis in Human Breast Cancer Cells

Fungal endophytes are known to be a paragon for producing bioactive compounds with a variety of pharmacological importance. The current study aims to elucidate the molecular alterations induced by the bioactive compounds produced by the fungal endophyte Colletotrichum gloeosporioides in the tumor microenvironment of human breast cancer cells. GC/MS analysis of the ethyl acetate (EA) extract of C. gloeosporioides revealed the presence of bioactive compounds with anticancer activity. The EA extract of C. gloeosporioides exerted potential plasmid DNA protective activity against hydroxyl radicals of Fenton's reagent. The cytotoxic activity further revealed that MDA-MB-231 cells exhibit more sensitivity toward the EA extract of C. gloeosporioides as compared to MCF-7 cells, whereas non-toxic to non-cancerous HEK293T cells. Furthermore, the anticancer activity demonstrated by the EA extract of C. gloeosporioides was studied by assessing nuclear morphometric analysis and induction of apoptosis in MDA-MB-231 and MCF-7 cells. The EA extract of C. gloeosporioides causes the alteration in cellular and nuclear morphologies, chromatin condensation, long-term colony inhibition, and inhibition of cell migration and proliferation ability of MDA-MB-231 and MCF-7 cells. The study also revealed that the EA extract of C. gloeosporioides treated cells undergoes apoptosis by increased production of reactive oxygen species and significant deficit in mitochondrial membrane potential. Our study also showed that the EA extract of C. gloeosporioides causes upregulation of pro-apoptotic (BAX, PARP, CASPASE-8, and FADD), cell cycle arrest (P21), and tumor suppressor (P53) related genes. Additionally, the downregulation of antiapoptotic genes (BCL-2 and SURVIVIN) and increased Caspase-3 activity suggest the induction of apoptosis in the EA extract of C. gloeosporioides treated MDA-MB-231 and MCF-7 cells. Overall, our findings suggest that the bioactive compounds present in the EA extract of C. gloeosporioides promotes apoptosis by altering the genes related to the extrinsic as well as the intrinsic pathway. Further in vivo study in breast cancer models is required to validate the in vitro observations.

Epinephrine facilitates the growth of T cell lymphoma by altering cell proliferation, apoptosis, and glucose metabolism

In recent years, studies have reported the role of stress-regulatory hormones, including epinephrine, in regulating the progression of a few cancers. However, the tumor-promoting action of epinephrine is not yet investigated in T cell malignancy, a rare and complicated neoplastic disorder. More so, very little is known regarding the implication of epinephrine in the glucose metabolic rewiring in tumor cells. The present investigation showed that epinephrine enhanced the proliferation of T lymphoma cells through up- and down-regulating the expression of PCNA, cyclin D, and p53, respectively. In addition, epinephrine inhibited apoptosis in T lymphoma cells possibly by increasing the level of BCL2 (an anti-apoptotic protein) and decreasing PARP level (a pro-apoptotic protein). Intriguingly, epinephrine is reported to stimulate glycolysis in T lymphoma cells by increasing the expression of crucial glycolysis regulatory molecules, namely HKII and PKM2, in a HIF-1α-dependent manner. Moreover, augmented production of ROS has been observed in T lymphoma cells, which might be a central player in epinephrine-mediated T cell lymphoma growth. Taken together, our study demonstrates that epinephrine might have a significant role in the progression of T cell lymphoma.

Phosphodiesterase 5 inhibitor sildenafil potentiates the antitumor activity of cisplatin by ROS-mediated apoptosis: a role of deregulated glucose metabolism

Cyclic nucleotide phosphodiesterase 5 (PDE5) has been recently identified to play a crucial role in the progression of many cancers. PDE5 promotes tumorigenesis by dysregulating various cellular processes such as proliferation, apoptosis, angiogenesis, and invasion and migration. Interestingly, multiple studies have reported the promising chemosensitizing potential of PDE5 inhibitor sildenafil in breast, colon, prostate, glioma, and lung cancers. However, to date, the chemosensitizing action of sildenafil is not evaluated in T cell lymphoma, a rare and challenging neoplastic disorder. Hence, the present investigation was undertaken to examine the chemosensitizing potential of sildenafil against T cell lymphoma along with elucidation of possible involvement of altered apoptosis and glucose metabolism. The experimental findings of this study showed that sildenafil enhances the cytotoxic ability of cisplatin by apoptosis induction through altering the levels of apoptosis regulatory molecules: Bcl-2, Bax, cytochrome c (Cyt c), cleaved caspase-3, and poly (ADP-ribose) polymerase (PARP). These molecular alterations were possibly driven by sildenafil through reactive oxygen species (ROS). Sildenafil deregulates glucose metabolism by markedly lowering the expression of glycolysis regulatory molecules, namely glucose transporter 1 (GLUT1), lactate dehydrogenase A (LDHA), hexokinase II (HKII), pyruvate kinase M2 (PKM2), and pyruvate dehydrogenase kinase 1 (PDK1) via suppressing hypoxia-inducible factor 1-alpha (HIF-1α) expression. Hence, sildenafil potentiates the tumor cell killing ability of cisplatin by augmenting ROS production through switching the glucose metabolism from glycolysis to oxidative phosphorylation (OXPHOS). Overall, our study demonstrates that sildenafil might be a promising adjunct therapeutic candidate in designing novel combinatorial chemotherapeutic regimens against T cell lymphoma.

Nimbolide retards T cell lymphoma progression by altering apoptosis, glucose metabolism, pH regulation, and ROS homeostasis

Nimbolide is reported as one of the potential anticancer candidates of the neem tree (Azadirachta indica A. Juss). The cytotoxic action of nimbolide has been well reported against a wide number of malignancies, including breast, prostate, lung, liver, and cervix cancers. Interestingly, only a few in vivo studies conducted on B cell lymphoma, glioblastoma, pancreatic cancer, and buccal pouch carcinoma have shown the in vivo antitumor efficacy of nimbolide. Therefore, it is highly needed to examine the in vivo antineoplastic activity of nimbolide on a wide variety of cancers to establish nimbolide as a promising anticancer drug. In the present study, we investigated the tumor retarding action of nimbolide in a murine model of T cell lymphoma. We noticed significantly augmented apoptosis in nimbolide- administered tumor-bearing mice, possibly due to down-regulated expression of Bcl2 and up-regulated expression of p53, cleaved caspase-3, Cyt c, and ROS. The nimbolide treatment-induced ROS production by suppressing the expression of antioxidant regulatory enzymes, namely superoxide dismutase and catalase. In addition, nimbolide administration impaired glycolysis and pH homeostasis with concomitant inhibition of crucial glycolysis and pH regulatory molecules such as GLUT3, LDHA, MCT1, and V-ATPase, CAIX and NHE1, respectively. Taken together, the present investigation provides novel insights into molecular mechanisms of nimbolide inhibited T cell lymphoma progression and directs the utility of nimbolide as a potential anticancer therapeutic drug for the treatment of T cell lymphoma.

Targeting lysophosphatidic acid receptor with Ki16425 impedes T cell lymphoma progression through apoptosis induction, glycolysis inhibition, and activation of antitumor immune response

Lysophosphatidic acid (LPA) is a small phospholipid that acts as an extracellular lipid mediator. It promotes cancer progression by altering a wide array of cellular processes, including apoptosis, survival, angiogenesis, invasion, and migration through binding with its cognate receptors. Intriguingly, our previous study showed that in vitro treatment of LPA induced survival of T lymphoma cells. Hence, the present investigation was designed to investigate the antitumor potential of Ki16425, an antagonist of LPA receptors, against T cell lymphoma. Our in vitro results showed inhibition of LPA-mediated survival and metabolic activity of T lymphoma cells by Ki16425. Further, in vivo experimental findings indicated the tumor retarding potential of Ki16425 against T cell lymphoma through apoptosis induction, glycolysis inhibition, and immunoactivation. The administration of Ki16425 triggered apoptosis by down-regulating the expression of Bcl2 and up-regulating p53, Bax, cleaved caspase-3, and Cyt c expression. Further, Ki16425 suppressed glycolytic activity with concomitantly decreased expression of GLUT3 and MCT1. Moreover, we also noticed an elevated level of NO and iNOS in tumor cells after Ki16425 administration which might also be responsible for apoptosis induction and suppressed glycolysis. Additionally, we observed an increased population of total leukocytes, lymphocytes, and monocytes along with increased thymocytes count and IL-2 and IFN-γ levels. Besides, we observed amelioration of tumor-induced kidney and liver damages by Ki16425. Taken together, this is the first study that demonstrates that LPA receptors could be potential future therapeutic targets for designing promising therapeutic strategies against T cell lymphoma.

Nimbolide inhibits 2D and 3D prostate cancer cells migration, affects microtubules and angiogenesis and suppresses B-RAF/p.ERK-mediated in vivo tumor growth

BACKGROUND

Prostate cancer (PCa) is the most prominent malignancy among men worldwide. PCa cells have a high tendency to metastasize to various distant organs, and this activity is the main cause of PCa mortality. Nimbolide is a promising phytochemical constituent of neem Azadirachta indica (Meliaceae). Previous studies showed that nimbolide exhibited potent anticancer activity however, its role against PCa tumorigenesis has not been fully elucidated.

PURPOSE

Our work aims to explore the role of nimbolide in regulating the essential tumor-associated processes involved in the metastatic cascade in PCa cells.

STUDY DESIGN

Cytotoxicity assay, wound healing and spheroid invasion assays, western blotting, immunofluorescence, tube-formation assay, in vivo and immunohistochemistry.

METHODS

The cytotoxicity of nimbolide towards PCa cell lines was assessed by resazurin assays. The cell mobility and migration of nimbolide-treated DU145 cells were determined by wound healing and spheroid invasion assays. Tubulin network was visualized using U2OS cells and DU145 cells. The effect of nimbolide on E-cadherin, β-catenin, acetylated α-tubulin and HDAC6 protein expressions levels were measured by Western blot. The potentiality of nimbolide to inhibit angiogenesis was revealed by HUVEC tube-formation assay. Nimbolide antitumor effect was studied in a syngeneic model of murine prostate cancer.

RESULTS

The current study indicated that nimbolide negatively affected the migratory and invasive capacity of DU145 prostate cancer cells in 2D and three-dimensional (3D) spheroid cultures. Interestingly, nimbolide induced downregulation of E-cadherin without any influence on the expression level of β-catenin. Additionally, we demonstrated that nimbolide influenced the microtubule network which was supported by the upregulation of acetylated α-tubulin and the reduction in HDAC6 protein. Moreover, the inhibitory effect of nimbolide on angiogenesis was clearly observed in HUVEC tube formation assay. In vivo experiments revealed the significant suppression of PCa growth and targeting of the B-RAF/p.ERK signaling pathway by nimbolide.

CONCLUSION

Our results showed that nimbolide inhibited 2D and 3D prostate cancer cells migration and downregulated E-cadherin protein expression, a marker for metastatic chemoresistance and tumor recurrence. Nimbolide stabilized the microtubules, combated angiogenesis and suppressed B.RAF/ERK-mediated in vivo tumor growth. Nimbolide may be considered as potential therapeutic agent for metastatic and advanced PCa patients and merits further investigations.

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.