cytochrome-c-t and thymoquinone

Thymoquinone (TQ) is the main active constituent of Nigella sativa. The present study aimed to investigate the effect of TQ on apoptotic parameters and MMP-9 expression in isoproterenol (ISP)-induced myocardial infarction (MI). TQ was given once daily for 7 days at doses of 10 and 20 mg/kg orally with ISP (86 mg/kg; s.c.) administered on the sixth and seventh days. TQ pre-treatment protected against ISP-induced MI as approved by normalisation of electrocardiogram (ECG) and b (CK)-MB, minimal histopathological changes, and reduction of the infarction size. Effects of TQ could be supported by its antioxidant activity, evidenced by the increase of cardiac reduced glutathione and total serum antioxidant capacity, and the inhibition of ISO-induced lipid peroxidation. TQ anti-inflammatory activity was associated with reduced expression of NF-κB and TNF-α. TQ ameliorated cardiomyocytes

Topics: Animals; Apoptosis; Benzoquinones; Biomarkers; Cytochromes c; Gene Expression Regulation, Enzymologic; Inflammation; Isoproterenol; Matrix Metalloproteinase 9; Myocardial Infarction; Random Allocation; Rats; Rats, Wistar

Glioma is one of the most aggressive primary brain tumors and is incurable. Surgical resection, radiation, and chemotherapies have been the standard treatments for brain tumors, however, they damage healthy tissue. Therefore, there is a need for safe anticancer drug delivery systems. This is particularly true for natural prodrugs such as thymoquinone (TQ), which has a high therapeutic potential for cancers but has poor water solubility and insufficient targeting capacity. We have tailored novel core-shell nanoformulations for TQ delivery against glioma cells using mesoporous silica nanoparticles (MSNs) as a carrier.. The core-shell nanoformulations were prepared with a core of MSNs loaded with TQ (MSNTQ), and the shell consisted of whey protein and gum Arabic (MSNTQ-WA), or chitosan and stearic acid (MSNTQ-CS). Nanoformulations were characterized, studied for release kinetics and evaluated for anticancer activity on brain cancer cells (SW1088 and A172) and cortical neuronal cells-2 (HCN2) as normal cells. Furthermore, they were evaluated for caspase-3, cytochrome c, cell cycle arrest, and apoptosis to understand the possible anticancer mechanism.. TQ release was pH-dependent and different for core and core-shell nanoformulations. A high TQ release from MSNTQ was detected at neutral pH 7.4, while a high TQ release from MSNTQ-WA and MSNTQ-CS was obtained at acidic pH 5.5 and 6.8, respectively; thus, TQ release in acidic tumor environment was enhanced. The release kinetics fitted with the Korsmeyer-Peppas kinetic model corresponding to diffusion-controlled release. Comparative in vitro tests with cancer and normal cells indicated a high anticancer efficiency for MSNTQ-WA compared to free TQ, and low cytotoxicity in the case of normal cells. The core-shell nanoformulations significantly improved caspase-3 activation, cytochrome c triggers, cell cycle arrest at G2/M, and apoptosis induction compared to TQ.. Use of MSNs loaded with TQ permit improved cancer targeting and opens the door to translating TQ into clinical application. Particularly good results were obtained for MSNTQ-WA.

Topics: Antineoplastic Agents; Apoptosis; Benzoquinones; Biocompatible Materials; Brain; Calorimetry, Differential Scanning; Caspase 3; Cell Cycle Checkpoints; Cell Line, Tumor; Chitosan; Cytochromes c; Diffusion; Drug Compounding; Drug Delivery Systems; Drug Liberation; Enzyme Activation; Glioma; Humans; Hydrogen-Ion Concentration; Inhibitory Concentration 50; Kinetics; Nanoparticles; Porosity; Silicon Dioxide; Spectroscopy, Fourier Transform Infrared; Thermogravimetry

Apoptosis induction of cancer cells can be an appropriate strategy by which chemotherapeutic agents kill tumor cells. The aim of the present study was to investigate the effect of temozolomide and thymoquinone combination on apoptotic pathway of human glioblastoma multiforme cell line (U87MG). U87MG cells were cultured, treated with temozolomide and thymoquinone, and cell proliferation was measured. Apoptosis cell death and its possible mechanism were investigated by various methods. Combination of temozolomide and thymoquinone had a synergistic effect on cells viability. Thymoquinone intensified the temozolomide-induced apoptosis. Combination of temozolomide and thymoquinone can be a good strategy for treatment of glioblastoma.

Topics: Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Benzoquinones; Brain Neoplasms; Cell Line, Tumor; Comet Assay; Cytochromes c; Dacarbazine; Drug Synergism; Glioblastoma; Glutathione; Humans; In Situ Nick-End Labeling; Membrane Potential, Mitochondrial; Nitric Oxide; Reactive Oxygen Species; Staining and Labeling; Temozolomide

Renal carcinoma is a common and frequently fatal carcinoma occurring worldwide and death rates due to this carcinoma are increasing with time. In the present study, we investigated the potential of thymoquinone a natural compound to induce apoptosis in renal carcinoma Caki cells. Thymoquinone efficiently enhanced the apoptotic population of Caki cells in a dose-dependent manner. Moreover, thymoquinone-mediated apoptosis caused downregulation of c-FLIP and Bcl-2, the master regulators of the anti-apoptotic mechanism. However, we did not find any changes in mRNA expression level of c-FLIP, therefore; this regulation of c-FLIP was a result of post-translation modification by thymoquinone. In contrast, expression of the Bcl-2 protein was observed at both transcriptional and translational level. However, we also observed that thymoquinone enhanced the level of intracellular reactive oxygen species (ROS) in Caki cells, which resulted in reduction of mitochondrial membrane potential (MMP) and cytochrome c release into cytoplasm. Our results postulate that thymoquinone induces apoptosis through downregulating c-FLIP and Bcl-2 which can be utilized as a chemotherapeutic agent to treat renal carcinoma.

Topics: Apoptosis; Benzoquinones; Carcinoma, Renal Cell; CASP8 and FADD-Like Apoptosis Regulating Protein; Cell Line, Tumor; Cytochromes c; Gene Expression Regulation, Neoplastic; Humans; Membrane Potential, Mitochondrial; Proto-Oncogene Proteins c-bcl-2; Reactive Oxygen Species; RNA, Messenger

Exposure to ethanol during early development triggers severe neuronal death by activating multiple stress pathways and causes neurological disorders, such as fetal alcohol effects or fetal alcohol syndrome. This study investigated the effect of ethanol on intracellular events that predispose developing neurons for apoptosis via calcium-mediated signaling. Although the underlying molecular mechanisms of ethanol neurotoxicity are not completely determined, mitochondrial dysfunction, altered calcium homeostasis and apoptosis-related proteins have been implicated in ethanol neurotoxicity. The present study was designed to evaluate the neuroprotective mechanisms of metformin (Met) and thymoquinone (TQ) during ethanol toxicity in rat prenatal cortical neurons at gestational day (GD) 17.5.. We found that Met and TQ, separately and synergistically, increased cell viability after ethanol (100 mM) exposure for 12 hours and attenuated the elevation of cytosolic free calcium [Ca²⁺]c. Furthermore, Met and TQ maintained normal physiological mitochondrial transmembrane potential (ΔψM), which is typically lowered by ethanol exposure. Increased cytosolic free [Ca²⁺]c and lowered mitochondrial transmembrane potential after ethanol exposure significantly decreased the expression of a key anti-apoptotic protein (Bcl-2), increased expression of Bax, and stimulated the release of cytochrome-c from mitochondria. Met and TQ treatment inhibited the apoptotic cascade by increasing Bcl-2 expression. These compounds also repressed the activation of caspase-9 and caspase-3 and reduced the cleavage of PARP-1. Morphological conformation of cell death was assessed by TUNEL, Fluoro-Jade-B, and PI staining. These staining methods demonstrated more cell death after ethanol treatment, while Met, TQ or Met plus TQ prevented ethanol-induced apoptotic cell death.. These findings suggested that Met and TQ are strong protective agents against ethanol-induced neuronal apoptosis in primary rat cortical neurons. The collective data demonstrated that Met and TQ have the potential to ameliorate ethanol neurotoxicity and revealed a possible protective target mechanism for the damaging effects of ethanol during early brain development.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Benzimidazoles; Benzoquinones; Calcium; Carbocyanines; Caspases; Cell Survival; Cells, Cultured; Central Nervous System Depressants; Cerebral Cortex; Cytochromes c; Embryo, Mammalian; Ethanol; Female; Fluoresceins; In Situ Nick-End Labeling; Indoles; Membrane Potential, Mitochondrial; Metformin; Neurons; Neuroprotective Agents; Organic Chemicals; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerases; Pregnancy; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Statistics, Nonparametric

A major concern of cancer chemotherapy is the side effects caused by the non-specific targeting of both normal and cancerous cells by therapeutic drugs. Much emphasis has been placed on discovering new compounds that target tumour cells more efficiently and selectively with minimal toxic effects on normal cells.. The cytotoxic effect of thymoquinone, a component derived from the plant Nigella sativa, was tested on human glioblastoma and normal cells. Our findings demonstrated that glioblastoma cells were more sensitive to thymoquinone-induced antiproliferative effects. Thymoquinone induced DNA damage, cell cycle arrest and apoptosis in the glioblastoma cells. It was also observed that thymoquinone facilitated telomere attrition by inhibiting the activity of telomerase. In addition to these, we investigated the role of DNA-PKcs on thymoquinone mediated changes in telomere length. Telomeres in glioblastoma cells with DNA-PKcs were more sensitive to thymoquinone mediated effects as compared to those cells deficient in DNA-PKcs.. Our results indicate that thymoquinone induces DNA damage, telomere attrition by inhibiting telomerase and cell death in glioblastoma cells. Telomere shortening was found to be dependent on the status of DNA-PKcs. Collectively, these data suggest that thymoquinone could be useful as a potential chemotherapeutic agent in the management for brain tumours.

Topics: Antineoplastic Agents; Apoptosis; bcl-2-Associated X Protein; Benzoquinones; Brain; Cell Line, Tumor; Cell Survival; Cytochromes c; DNA Damage; DNA Repair; DNA-Activated Protein Kinase; Dose-Response Relationship, Drug; Gene Expression Regulation, Neoplastic; Glioblastoma; Humans; Nuclear Proteins; Telomerase; Telomere

Previous studies have shown biological activity of thymoquinone, an active compound extracted from Nigella sativa, in pancreatic cancer cells; however, preclinical animal studies are lacking. Here, we report, for the first time, the chemosensitizing effect of thymoquinone to conventional chemotherapeutic agents both in vitro and in vivo using an orthotopic model of pancreatic cancer. In vitro studies revealed that preexposure of cells with thymoquinone (25 mumol/L) for 48 h followed by gemcitabine or oxaliplatin resulted in 60% to 80% growth inhibition compared with 15% to 25% when gemcitabine or oxaliplatin was used alone. Moreover, we found that thymoquinone could potentiate the killing of pancreatic cancer cells induced by chemotherapeutic agents by down-regulation of nuclear factor-kappaB (NF-kappaB), Bcl-2 family, and NF-kappaB-dependent antiapoptotic genes (X-linked inhibitors of apoptosis, survivin, and cyclooxygenase-2). As shown previously by our laboratory, NF-kappaB gets activated on exposure of pancreatic cancer cells to conventional chemotherapeutic agents; interestingly, thymoquinone was able to down-regulate NF-kappaB in vitro, resulting in chemosensitization. In addition to in vitro results, here we show for the first time, that thymoquinone in combination with gemcitabine and/or oxaliplatin is much more effective as an antitumor agent compared with either agent alone. Most importantly, our data also showed that a specific target, such as NF-kappaB, was inactivated in animal tumors pretreated with thymoquinone followed by gemcitabine and/or oxaliplatin. These results provide strong in vivo molecular evidence in support of our hypothesis that thymoquinone could abrogate gemcitabine- or oxaliplatin-induced activation of NF-kappaB, resulting in the chemosensitization of pancreatic tumors to conventional therapeutics.

Topics: Animals; Antineoplastic Agents; Apoptosis; Benzoquinones; Caspases; Cell Cycle; Cell Division; Cell Line, Tumor; Cell Survival; Cytochromes c; Deoxycytidine; Dinoprostone; Drug Synergism; Female; Gemcitabine; Humans; Mice; Mice, Inbred ICR; Mice, SCID; NF-kappa B; Organoplatinum Compounds; Oxaliplatin; Pancreatic Neoplasms