Depletion Of Glutathione Levels Research Articles

Targeting xCT with sulfasalazine suppresses triple-negative breast cancer growth via inducing autophagy and coordinating cell cycle and proliferation.

There is a substantial unmet need for effective treatment strategies in triple-negative breast cancer (TNBC). Recently, renewed attention has been directed towards targeting glutamine (Gln) metabolism to enhance the efficacy of cancer treatment. Nonetheless, a comprehensive exploration into the mechanistic implications of targeting Gln metabolism in TNBC is lacking. In this study, our objective was to probe the sensitivity of TNBC to alterations in Gln metabolism, using representative TNBC cell lines: MDA-MB-231, MDA-MB-468, and 4T1. Through an integration of bioinformatics, in-vitro, and in-vivo investigations, we demonstrated that sulfasalazine (SAS), like erastin (a known xCT inhibitor), effectively suppressed the expression and transport function of xCT, resulting in a depletion of glutathione levels in MDA-MB-231 and MDA-MB-468 cells. Furthermore, both xCT knockdown and SAS treatment demonstrated the promotion of cellular autophagy. We unveiled a positive correlation between xCT and the autophagy-related molecule p62, their co-expression indicating poor survival outcomes in breast cancer patients. In addition, our research revealed the influence of SAS and xCT on the expression of proteins regulating cell cycle and proliferation. Treatment with SAS or xCT knockdown led to the inhibition of MYC, CDK1, and CD44 expression. Significantly, the combined administration of SAS and rapamycin exhibited a synergistic inhibitory effect on the growth of transplanted breast tumor in mouse models constructed from murine-derived 4T1 cells. Taken together, our findings suggested the potential and clinical relevance of the SAS and rapamycin combination in the treatment of TNBC.

Raman spectroscopic analysis of human serum samples of convalescing COVID-19 positive patients

Rapid screening, detection and monitoring of viral infection is of critical importance, as exemplified by the rapid spread of SARS-CoV-2, leading to the worldwide pandemic of COVID-19. This is equally the case for the stages of patient convalescence as for the initial stages of infection, to understand the medium and long terms effects, as well as the efficacy of therapeutic interventions. Optical spectroscopic techniques potentially offer an alternative to currently employed techniques of screening for the presence, or the response to infection. In this study, the ability of Raman spectroscopy to distinguish between samples of the serum of convalescent COVID-19 positive patients and COVID-19 negative serum samples, and to further analyse and quantify systemic responses, was explored. The study included serum samples of patients who had been tested for SARS-CoV-2 specific IgG and IgM responses between 25 and 134 days after the infection was identified. Both COVID-19 positive and negative groups included males and females who ranged in age from 21 to 81 years old. No correlation was apparent between the specified SARS-CoV-2 specific IgG and IgM immunoglobulin levels of the positive group, their sex, or age. Raman spectroscopic measurements were performed at 785 nm, in liquid serum, thawed from frozen, and spectra were pre-processed to remove the contribution of water, normalising to the water content. Principal components analysis of the spectral dataset over the range 400–1800 cm-1 provided no clear indication of a difference between normal serum and SARS-CoV-2 positive serum. A selection of 5 of the samples, which were available in sufficient volume, were fractionated by centrifugal filtration, and the 100 kDa, 50 kDa, 30 kDa, and 10 kDa concentrates similarly analysed by Raman spectroscopy. Partial least squares regression analysis revealed a negative correlation between the spectral profile of the 30 kDa fractions and SARS-CoV-2 specific IgG antibody levels, potentially indicating an association with depleted glutathione levels. The study supports a potential role of Raman screening of blood serum for monitoring of SARS-CoV-2 infection, but also in longitudinal studies of disease progression, long term effects, and therapeutic interventions.

Luteolin photo-protects zebrafish from environmental stressor ultraviolet radiation (UVB)

ABSTRACT Ultraviolet B wavelength ray radiation (UVB) is an environmental stressor with detrimental effects to the aquatic and human systems but also enhances adverse effects when combined with several other environmental factors such as temperature and pollution. UV rays induce cellular oxidative damage and impair motility. This study aimed to examine the photo-protective activity of flavonoid luteolin against UV-B irradiation-induced oxidative stress and cellular damage using zebrafish. An in-vivo photoaging model was established using UV-B irradiation in zebrafish larvae exposed to 100 mJ/cm2. Data demonstrated that UV-B irradiation of swimming water enhanced production of ROS and superoxide anions as well as depleted total glutathione levels in zebrafish larvae. UV-B irradiation also triggered cellular damage and membrane rupture in zebra fish. Further, 100 mJ/cm2 of UV-B radiation exposure to adult-wild type zebrafish co-exposed with intraperitoneally (ip) injected luteolin upregulated the local neuroendocrine axes by activating vascular endothelial growth factor (VEGF) and elevating levels of pro-inflammatory cytokines IL-1β and TNF-α. Histologically, UV-B irradiation induced skin lesions and locomotory defects with clumping and degeneration of brain glial cells. However, luteolin effectively inhibited the excess production of reactive oxygen species (ROS) and decreased superoxide anion levels induced by UV-B irradiation. Luteolin restored the depleted glutathione levels. In addition, luteolin blocked apoptosis and lipidperoxidation. Luteolin protected adult zebrafish by downregulating the pro-inflammatory cytokine protein expression levels and diminishing VEGF activation. Luteolin also alleviated locomotory defects by inhibiting activation of microglia and inflammatory responses by preventing accumulation of glial cells and vacuolation. Data demonstrate that luteolin may protect zebrafish from UV-B-induced photodamage through DNA-protective, antioxidant and anti-inflammatory responses.

Natural Compounds and Glutathione: Beyond Mere Antioxidants.

The tripeptide glutathione plays important roles in many cell processes, including differentiation, proliferation, and apoptosis; in fact, disorders in glutathione homeostasis are involved both in the etiology and in the progression of several human diseases, including cancer. Natural compounds have been found to modulate glutathione levels and function beyond their role as mere antioxidants. For example, certain compounds can upregulate the expression of glutathione-related enzymes, increase the availability of cysteine, the limiting amino acid for glutathione synthesis, or directly interact with glutathione and modulate its function. These compounds may have therapeutic potential in a variety of disease states where glutathione dysregulation is a contributing factor. On the other hand, flavonoids' potential to deplete glutathione levels could be significant for cancer treatment. Overall, while natural compounds may have potential therapeutic and/or preventive properties and may be able to increase glutathione levels, more research is needed to fully understand their mechanisms of action and their potential benefits for the prevention and treatment of several diseases. In this review, particular emphasis will be placed on phytochemical compounds belonging to the class of polyphenols, terpenoids, and glucosinolates that have an impact on glutathione-related processes, both in physiological and pathological conditions. These classes of secondary metabolites represent the most food-derived bioactive compounds that have been intensively explored and studied in the last few decades.

UBA52 Attunes VDAC1-Mediated Mitochondrial Dysfunction and Dopaminergic Neuronal Death.

Mitochondrial homeostasis regulates energy metabolism, calcium buffering, cell function, and apoptosis. The present study has been conducted to investigate the implications of the ubiquitin-encoding gene UBA52 in mitochondrial physiology. Transient expression of Myc-UBA52 in neurons significantly inhibited the rotenone-induced increase in reactive oxygen species generation, nitrite level, and depleted glutathione level. Mass spectrometric and coimmunoprecipitation data suggested the profound interaction of UBA52 with mitochondrial outer membrane channel protein, VDAC1 in both the wild-type and Myc-α-synuclein overexpressed neuronal cells and in the Parkinson's disease (PD)-specific substantia nigra and striatal region of the rat brain. In vitro ubiquitylation assay revealed that UBA52 participates in the ubiquitylation of VDAC1 through E3 ligase CHIP. Myc-UBA52 overexpression in neurons further improved the mitochondrial functionality and cell viability by preventing the alteration in mitochondrial membrane potential, mitochondrial complex I activity, and translocation of cytochrome c and p-Nrf2 along with the effect on intracellular calcium uptake, thus collectively inhibiting the opening of mitochondrial permeability transition pore. Additionally, Myc-UBA52 expression in neuronal cells offered protection against apoptotic and autophagic cell death. Altogether, our findings delineate a functional association between UBA52 and mitochondrial homeostasis, providing new insights into the deterrence of dopaminergic cell death during acute PD pathogenesis.

Nimbin analogs N5 and N7 regulate the expression of lipid metabolic genes and inhibit lipid accumulation in high-fat diet-induced zebrafish larvae: An antihyperlipidemic study

BackgroundExcess accumulation of lipids leads to obesity. Triterpenoids are a group of plant compounds which poses various biological activities. The biological activities of Nimbin analogs N5 and N7 were addressed in this study on inhibiting lipid aggregation and underlying the derivatives molecular mechanisms for a therapeutical approach. AimThis study aims to evaluate the anti-adipogenic activity of semi-natural Nimbin analogs, N5 and N7, on zebrafish larvae induced with oxidative stress due to a high-fat diet (HFD) and adipogenesis using specific fluorescent stains. Materials and methodsZebrafish at 4 days post fertilized (dpf) larvae were divided into groups for the HFD diet along with exposure to various concentrations of N5 and N7. HFD induced accumulation of neutral lipids and triglycerides (Oil Red O and Nile red staining, respectively) with weight gain, which generated intracellular ROS (DCFH-DA staining) and superoxide anion production (DHE staining) with depleted glutathione levels (NDA staining) were assayed. HFD exposure promoted the accumulation of inflammatory macrophages (Neutral red staining) and impaired glucose metabolism (2NBDG staining). The ability of N5 and N7 to reduce total regulating lipogenic specific genes C/EBP-α, SREBP-1 and FAS were evaluated using relative gene expression. Key findingsThe Nimbin analogues N5 and N7 suppressed adipogenesis, forming intracellular ROS and superoxide anion while simultaneously restoring glutathione levels. The analogues significantly lowered total TC and TG levels, prevented inflammatory macrophage build-up and boosted glucose absorption. Also, N5 and N7 down-regulate the lipogenic-specific genes. SignificanceNimbin analogs N5 and N7 enhance lipolysis and inhibit adipogenesis in in-vivo zebrafish larvae model.

Abstract 2176: NADPH production and redox homeostasis regulate acinar to ductal metaplasia

Abstract Activating mutations in KRAS reprogram cellular metabolism to support continuous growth, proliferation, and survival in pancreatic cancer. However, there is little information on how KRAS-dependent alterations in metabolism change precancerous states and cancer initiation. Acinar cells can give rise to pancreatic tumors through acinar-to-ductal metaplasia (ADM), a reversible cell state that persists and progresses to neoplasia and cancer with oncogenic KRAS. During ADM, acinar cells transdifferentiate to duct-like cells, a process we hypothesized was mediated by metabolic rewiring. We performed transcriptomic analysis on acinar cells undergoing ADM and found metabolic programs are globally enhanced. Indeed, we and others have demonstrated how inhibiting metabolic pathways necessary for ADM can prevent transdifferentiation and tumorigenesis. A detailed analysis of our data revealed that the transcripts for NADPH-producing enzymes, Glucose-6-phosphate dehydrogenase (G6pd) and Malic enzyme 1 (Me1), were significant enriched during ADM. Following these results, we obtained G6pd-mutant mice and generated Me1flox/flox mice and bred them into the KC (KrasLSL-G12D/+;Ptf1aCre/+) line, resulting in KCG (KrasLSL-G12D/+;Ptf1aCre/+;G6pdmut/mut) and KCM (KrasLSL-G12D/+;Ptf1aCre/+;Me1flox/flox) mice. Interestingly, KCG and KCM mice develop ADM and neoplasia faster than their KC counterparts. We also observe that acinar cells and ADM in KCG cells have higher levels of lipid peroxidation and reactive oxygen species (ROS) both in vivo and using primary ex vivo acinar cell cultures. Thus, increased ROS levels may underlie ADM acceleration in this system. In primary acinar cell culture, we can rescue the accelerated ADM phenotype in KCG cells with the addition of antioxidants. Furthermore, we find that treatment of wild type acinar cells with buthionine sulphoximine (BSO) to deplete glutathione levels and increase ROS also accelerates ADM in culture. These results suggest that NADPH and glutathione pools are important for regulating redox levels during ADM, and that reducing these pools leads to accelerated tumorigenesis. Together, this work demonstrates new metabolic pathways driving pancreatic cancer initiation. Citation Format: Megan D. Radyk, Barbara S. Nelson, Christopher J. Halbrook, Mengrou Shan, Jonathan Alektiar, Howard C. Crawford, Yatrik M. Shah, Costas A. Lyssiotis. NADPH production and redox homeostasis regulate acinar to ductal metaplasia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2176.

MEDB-90. Iron Imbalance Can Potentiate Cisplatin Response in Pediatric Medulloblastoma by Regulating Ferroptosis

Medulloblastoma (MB), the most common malignant pediatric brain tumor, is a leading cause of childhood mortality. Of the four primary subgroups, patients with group 3 tumors have the poorest prognosis. Loss of chromosome 17p is a high-risk feature associated with poor outcomes in group 3 tumors. We recently elucidated the tumor suppressive properties of a novel miR, miR-1253, on the terminal end of 17p. In further exploring its anti-neoplastic effects, we discovered that miR-1253 can disrupt iron homeostasis, causing oxidative stress and inducing lipid peroxidation. These concurrent events are capable of triggering an iron-mediated form of cell death called ferroptosis. Notably, our in silico interrogation of ferroptosis regulator genes (FRGs) in group 3 tumors revealed high expression of genes associated with iron transport and glutathione metabolism. These included mitochondrial iron transporters and GPX4, a critical regulator of ferroptosis. Restoration of miR-1253 expression in group 3 cell lines resulted in specific downregulation of ABCB7, an iron-sulfur cluster exporter, and GPX4. Consequently, cytosolic and mitochondrial labile iron pools rose, glutathione levels declined, and mitochondrial oxidative stress and lipid peroxidation were induced. These events were recapitulated by ABCB7 knockdown and potentiated cell death. Treating miR-1253-expressing cancer cells with cisplatin, a group 3 MB chemotherapeutic agent with ferroptotic properties, further elevated oxidative stress, depleted glutathione levels, and augmented lipid peroxidation, with added inhibitory effects on cell viability and colony formation. Treatment with a ferroptosis inhibitor (ferrostatin-1) lead to recovery from the cytotoxic effects of this combination therapy. Our studies highlight a novel mechanism for group 3 MB pathogenesis via ferroptosis regulation and provide a proof-of-concept for exploiting group 3 MB tumor vulnerability to iron imbalance as a novel treatment strategy.

Naja nigricollis venom altered reproductive and neurological functions via modulation of pro-inflammatory cytokines and oxidative damage in male rats

Reproductive and neurological anomalies are often characterized by malfunctioning of reproductive and nervous organs sometimes attributed to systemic toxins. However, limited information is available on the impact of snake venom toxins on male reproductive and nervous system. This study investigated the toxicological effects of Naja nigricollis venom on male reproductive and neural functions in rat model. Twenty male Wistar rats weighing between 195 and 230 g were divided randomly into two groups of ten rats each. Group 1 served as normal control while rats in group 2 were envenomed with a single intraperitoneal injection of 0.25 mg/kg−1 (LD12.5) of N. nigricollis venom on first and twenty fifth day within the period of fifty days experiment. The venom significantly decreased sperm counts, motile cells and volume combined with increased sperm abnormalities. The venom induced hormonal imbalances in the envenomed group as levels of testosterone, luteinizing and follicle stimulating hormones depreciated compared to the control. Oxidative stress biomarkers: malondialdehyde significantly increased parallels with depletion of glutathione level and catalase activities in testis, epididymis and brain of envenomed rats. Furthermore, N. nigricollis venom up-regulated tumor necrosis factor-alpha (TNF-α) and interleukin1-beta (IL-1β) production in testis, epididymis and brain of envenomed rats compared to the control. Also, various histological alterations were noticed in tissues of testis, epididymis and brain of envenomed rats. Findings indicated that N. nigricollis venom is capable of inducing reproductive and neurological dysfunction in envenomed victims.

Cannabis sativa L. protects against oxidative injury in kidney (vero) cells by mitigating perturbed metabolic activities linked to chronic kidney diseases

Ethnopharmacological relevanceCannabis sativa L. is among numerous medicinal plants widely used in traditional medicine in treating various ailments including kidney diseases. AimsThe protective effect of C. sativa on oxidative stress, cholinergic and purinergic dysfunctions, and dysregulated glucogenic activities were investigated in oxidative injured kidney (Vero) cell lines. MethodsFixed Vero cells were treated with sequential extracts (hexane, dichloromethane [DCM] and ethanol) of C. sativa leaves for 48 h before subjecting to MTT assay. Vero cells were further incubated with FeSO4 for 30 min, following pretreatment with C. sativa extracts for 25 min. Normal control consisted of Vero cells not treated with the extracts and/or FeSO4, while untreated (negative) control consisted of cells treated with only FeSO4. ResultsMTT assay revealed the extracts were slightly cytotoxic at the highest concentrations (250 μg/mL). There was a significant depletion in glutathione level and catalase activity on induction of oxidative stress, with significant elevation in malondialdehyde level, acetylcholinesterase, ATPase, ENTPDase, fructose-1,6-biphosphatase, glucose 6-phosphatase and glycogen phosphorylase activities. These activities and levels were significantly reversed following pretreatment with C. sativa extracts. ConclusionThese results portray the protective potentials of C. sativa against iron-mediated oxidative renal injury as depicted by the ability of its extracts to mitigate redox imbalance and suppress acetylcholinestererase activity, while concomitantly modulating purinergic and glucogenic enzymes activities in Vero cells.

Modulation of Antioxidant Defense in Farmed Rainbow Trout (Oncorhynchus mykiss) Fed with a Diet Supplemented by the Waste Derived from the Supercritical Fluid Extraction of Basil (Ocimum basilicum).

Phytotherapy is based on the use of plants to prevent or treat human and animal diseases. Recently, the use of essential oils and polyphenol-enriched extracts is also rapidly increasing in the aquaculture sector as a means of greater industrial and environmental sustainability. Previous studies assessed the antibacterial and antiparasitic effects of these bioactive compounds on fish. However, studies on the modulation of oxidative stress biomarkers are still scant to date. Thus, in this study, the modulation of antioxidant defense against oxidative stress exerted by fish diets supplemented with a basil supercritical extract (F1-BEO) was assessed in rainbow trout Oncorhynchus mykiss. The F1-BEO extracted with supercritical fluid extraction was added to the commercial feed flour (0.5, 1, 2, 3% w/w) and mixed with fish oil to obtain a suitable compound for pellet preparation. Fish were fed for 30 days. The levels of stress biomarkers such as superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase, glutathione reductase, glyoxalase I, glyoxalase II, lactate dehydrogenase, glutathione and malondialdehyde showed a boost in the antioxidant pathway in fish fed with a 0.5% F1-BEO-supplemented diet. Higher F1-BEO supplementation led to a failure of activity of several enzymes and the depletion of glutathione levels. Malondialdehyde concentration suggests a sufficient oxidative stress defense against lipid peroxidation in all experimental groups, except for a 3% F1-BEO-supplemented diet (liver 168.87 ± 38.79 nmol/mg prot; kidney 146.86 ± 23.28 nmol/mg prot), compared to control (liver 127.76 ± 18.15 nmol/mg prot; kidney 98.68 ± 15.65 nmol/mg prot). Our results suggest supplementing F1-BEO in fish diets up to 0.5% to avoid potential oxidative pressure in farmed trout.

Beneficial effect of the methanolic leaf extract of Allium hookeri on stimulating glutathione biosynthesis and preventing impaired glucose metabolism in type 2 diabetes

Oxidative stress resulting from the depletion of glutathione (GSH) level plays a vital role in generating various degenerative diseases, including type 2 diabetes (T2D). We tested the hypothesis that depleted glutathione levels can be enhanced and the impaired glucose metabolism can be prevented by supplementing Allium hookeri, a herb rich in organosulfur compounds, in a High Fat (HF) diet-induced T2D Male Sprague Dawley rat model. The experimental rats were divided into three groups (n = 6), namely normal diet, high-fat diet, and high-fat diet treated with A.hookeri methanolic leaf extract (250 mg/kg). Consumption of HF diet along with the plant extract resulted in significant reduction of the body weight (7.08%–14.89%) and blood glucose level (6.5%–16.4%) from the 13th week onward. There was a significant decrease in reactive oxygen species, oxidized glutathione (GSSG) levels, and an increase in GSH level in skeletal muscle tissues supplemented with the plant extract. The protein expressions of the signaling molecules such as GCLC and GR involved in GSH synthesis and of GLUT4 in glucose transport were also upregulated in the skeletal muscle tissues of the plant extract-treated group. Results of in vitro studies with muscle cell line (L6) further demonstrated the beneficial effect of the plant extract in increasing glucose uptake and maintaining the GSH/GSSH equilibrium via regulation of protein expression of GCLC/GR/GLUT4 signaling molecules in sodium palmitate (0.75 mM) treated cells. Overall this study suggests that dietary supplementation with Allium hookeri, can restore the glutathione level and regulate the blood glucose level in T2D.

Biochemical Assessment of Hyperhomocysteinemia-Mediated Oxidative Stress in Coronary Artery Disease Patients: A Hospital-Based Cross-Sectional Study

This study aimed to assess the status of B-vitamins (folate, vitamin B6, and B12) and homocysteine (HCY) in the sera of Omani coronary artery disease (CAD) patients. Sixteen Omani patients (10 males and 6 females) gave consent for blood sampling and were enrolled in the study on voluntary basis. All patients were evaluated for their anthropometric and biochemical measurements of B-vitamins, glutathione (reduced and oxidized), HCY, and quantification of N-homocysteinylated albumin protein. It was observed that both male and female patients had a comparable age (57.64 ±9.86, 56.5 ±10.04 years, respectively) with no significant difference, P = 0.69 and both genders were obese based on their body mass index (31.22 ± 8.17 kg/m2 for males and 30.26 ± 4.70 kg/m2for females). Serum levels of folate, vitamins B6, and B12 were lower than the normal reference values in all the study participants. There was depletion in glutathione levels (higher level of oxidized glutathione versus lower level of reduced glutathione) in the sera of all study participants. High serum HCY levels in both males and females (75.81±9.21 and 68.66±8.1 μmol/L, respectively) suggest that both males and females had hyperhomocysteinemia. Correlation coefficient analysis revealed that the serum HCY levels were negatively correlated with serum reduced glutathione, folic acid, vitamins B6, and B12 levels in both male and female study participants. The serum HCY level was positively correlated with age, body mass index, and serum oxidized glutathione. Proteomic measurements of N-homocysteinylation in serum albumin revealed that N-homocysteinylated albumin was present in all the assayed serum samples of study participants. The results suggest that low serum status of B-vitamins might act as a metabolic trigger for the observed hyperhomocysteinemia, oxidative stress, and pathological formation of N-homocysteinylated albumin protein, which collectively aggravates the CAD risk in the studied Omani patients.

Zinc-pretreatment triggers glutathione and Nrf2-mediated protection against inorganic mercury-induced cytotoxicity and intrinsic apoptosis in PC12 cells

Mercury (Hg) is a hazardous metal, poses environmental problems with severe human health effects; whereas zinc (Zn) is an essential micronutrient with antioxidant properties. The purpose of this research was to investigate the effect of Zn on inorganic Hg-induced cytotoxicity in the PC12 cells. The cells were treated with HgCl2 (5 μM) for 48 h with/without 1 h prior ZnCl2-treatment (100 μM) and deliberated for further analysis. After 48 h of incubation with only Hg2+, the cell showed reduced cell viability, compromised cell membrane, DNA degradation, depleted glutathione level, ROS generation and drastically increased apoptosis. Subsequently, Hg2+-treated cells demonstrated a significant downregulation of akt, mTOR, ERK1, Nrf2, HO1, Bcl-2, Bcl-xL, and upregulation of p53, Bax, cytochrome c and cleaved caspase 3, indicating intrinsic apoptosis induction. However, cells pretreated with Zn2+ before Hg2+-exposure showed a significant improvement in cell viability, cell membrane, DNA damage, glutathione level, ROS amount and apoptotic cells, with a significant upregulation in mTOR, akt, ERK1, Nrf2, HO1, Bcl-2 and Bcl-xL, and downregulation in p53, Bax, cytochrome c and cleaved caspase 3, indicating inhibition of apoptosis. The findings suggested that Zn2+-pretreatment not only improves glutathione content but also induces activation of Nrf2-HO1 pathway, which would tend to suppress Hg-cytotoxicity.

Kolaviron modulates dysregulated metabolism in oxidative pancreatic injury and inhibits intestinal glucose absorption with concomitant stimulation of muscle glucose uptake

This present study investigated the antioxidative and antidiabetic properties of kolaviron by analysing its inhibitory effect on key metabolic activities linked to T2D, in vitro and ex vivo. Kolaviron significantly inhibited α-glucosidase and α-amylase activities, and intestinal glucose absorption dose-dependently, while promoting muscle glucose uptake. Induction of oxidative pancreatic injury significantly depleted glutathione level, superoxide dismutase, catalase, and ATPase activities, while elevating malondialdehyde and nitric oxide levels, acetylcholinesterase and chymotrypsin activities. These levels and activities were significantly reversed in tissues treated with kolaviron. Kolaviron depleted oxidative-induced metabolites, with concomitant restoration of oxidative-depleted metabolites. It also inactivated oxidative-induced ascorbate and aldarate metabolism, pentose and glucuronate interconversions, fructose and mannose metabolism, amino sugar and nucleotide sugar metabolism, and arginine and proline metabolism, while reactivating selenocompound metabolism. These results depict the antidiabetic properties of kolaviron as indicated by its ability to attenuate oxidative-induced enzyme activities and dysregulated metabolisms, and modulated the enzyme activities linked to hyperglycaemia.

Thymoquinone reduces ischemia and reperfusion-induced intestinal injury in rats, through anti-oxidative and anti-inflammatory effects.

The aim of the present study was to investigate the effect of thymoquinone on ischemia/reperfusion (I/R) injury at 150 min or/and 24 h of reperfusion in male Wistar Rats. The therapeutic value of thymoquinone on cellular damage caused by reactive oxygene species or inflammatory processes during intestinal ischemia/reperfusion was investigated using pharmacological function studies on smooth muscle contractile responses of acetylcholine (Ach) and KCl, along with myeloperoxidase activity, malondialdehyhde, glutathione and cytokine levels such as tumor necrosis factor (TNF)-α and interleukin (IL)-1β in serum and ileum tissue of rats. Thymoquinone was administered at a dose of 50 mg/kg orally for three times: 30 min, 24 h and 48 h prior to the surgical procedure. Soon after reperfusion timing (150 min or 24 h), the contractility traces to KCl and acetylcholine of the ileum smooth muscle were recorded through isolated organ bath. Pretreatment with thymoquinone reversed the disrupted contractility of the ileum smooth muscle at the 24 h reperfusion. Increased malondialdehyde and depleted glutathione levels and high myeloperoxidase activity determined in the ileum I/R tissue returned to reasonable amounts by pretreatment of Thymoquinone, which attenuated malondialdehyde quantity, restored glutathione level and inhibited myeloperoxidase activity. In addition, both serum and tissue TNF-α and IL-1β activities were modulated by thymoquinone at 24 h of intestinal I/R. The results indicate that thymoquinone may have therapeutic value due to its immunomodulating, radical scavenging and/or antioxidant effects in intestinal I/R injury including oxidant damage mechanisms.

Protective effects of naringin against drugs and chemical toxins induced hepatotoxicity: A review.

The liver is a vital metabolic organ for drug and xenobiotic metabolism which is influenced by chemical and natural toxins. Liver injury is associated with systemic oxidative stress, which leads to cellular necrosis, fibrosis, tissue lipid peroxidation, and depletion in glutathione levels. Considering the lack of reliable hepato-protective drugs in modern medicine, plant-derived phytoconstituents seem to be a noteworthy option. Naringin is an abundant flavonoid found in citrus fruits with various pharmacological benefits such as antioxidant, anti-inflammatory, and antiapoptotic, activities. In this review, we summarize available data from recent studies about the hepatoprotective effects of naringin against chemical toxicants and discuss the possible mechanisms of actions.

Apoptosis induced by bruceineD in human non‑small‑cell lung cancer cells involves mitochondrial ROS‑mediated death signaling.

Bruceine D is one of the active components of Brucea javanica (L.) Merr., which is widely used to treat cancer in China. The aim of the present study was to evaluate the potential effect of bruceine D against non-small-cell lung cancer (NSCLC) cells and delineate its underlying mechanisms. The results indicated that treatment with bruceine D markedly inhibited the proliferation of wild-type NSCLC cells and epidermal growth factor receptor-mutant cells in a dose- and time-dependent manner, and significantly decreased the colony-forming ability and migration of A549 cells. Hoechst 33342 staining and flow cytometric analysis demonstrated that treatment with bruceine D effectively induced apoptosis of A549 cells. In addition, the proapoptotic effect of bruceine D was found to be associated with G0-G1 cell cycle arrest, accumulation of intracellular reactive oxygen species (ROS) and malondialdehyde, depletion of glutathione levels and disruption of mitochondrial membrane potential. Additionally, pretreatment with N-acetylcysteine, a ROS scavenger, significantly attenuated the bruceine D-induced inhibition in A549 cells. Western blotting demonstrated that treatment with bruceine D significantly suppressed the expression of the anti-apoptotic proteins Bcl-2, BclxL and X-linked inhibitor of apoptosis, enhanced the expression levels of apoptotic proteins Bax and Bak, and inhibited the expression of pro-caspase-3 and pro-caspase-8. Based on these results, it may be suggested that inhibition of A549 NSCLC cell proliferation by bruceine D is associated with the modulation of ROS-mitochondrial-mediated death signaling. This novel insight may provide further evidence to verify the anticancer efficacy of B. javanica, and support a role for bruceine D in the anti-NSCLC treatment.

Abstract 5267: Unbiased metabolic profiling of atypical teratoid/rhabdoid tumors predicts sensitivity to the glutamine metabolic inhibitor 6-diazo-5-oxo-L-norleucine

Abstract Atypical teratoid rhabdoid tumors (AT/RT) are deadly tumors of infancy in need of new, targeted therapies. Molecular analyses have revealed 3 epigenetically distinct subgroups of AT/RT. High MYC-expressing tumors are a particularly aggressive subgroup, with a 5-year median survival of 18.5%. MYC is difficult to directly target given large, flat, featureless protein-protein binding sites. We performed the first unbiased metabolic profile of AT/RT cell models by high-performance liquid chromatography-mass spectrometry. This study revealed that high MYC-expressing AT/RT have a unique metabolic profile (Partial Least Squares-Discriminant Analysis). Pathway analysis highlights a dependence on glutamine metabolism in high-MYC expressing AT/RT. High MYC-expressing cell lines grow poorly in glutamine-free media compared to low-MYC cell lines (MTS assay, glutamine-free media vs normal media). Due to this dependence on glutamine metabolism, we hypothesized that high-MYC expressing AT/RT would be especially sensitive to glutamine metabolic inhibitors. We show that the glutamine analogue, 6-diazo-5-oxo-L-norleucine (DON) slows high-MYC expressing AT/RT cell growth, induces high rates of apoptosis, and improves survival in orthotopic mouse models of high-MYC expressing AT/RT (p =0.0027 by log-rank test). In contrast, low-MYC expressing models are relatively insensitive to DON. In uniformly labeled glutamine metabolic analyses of AT/RT cells, DON treatment led to depletion of glutathione levels by preventing the production of glutamate. DON treatment synergized with carboplatin to kill AT/RT cells in vitro and extend the life of mice bearing AT/RT orthotopic xenografts (p< 0.001 by log rank test). We aim to translate these findings into a new clinical trial to improve survival in this deadly disease. Citation Format: Sabrina Z. Wang, Brad Poore, Jesse Alt, Antoinette Price, Sariah Allen, Brent Orr, Rana Rais, Barbara Slusher, Charles Eberhart, Eric H. Raabe, Jeffrey H. Rubens. Unbiased metabolic profiling of atypical teratoid/rhabdoid tumors predicts sensitivity to the glutamine metabolic inhibitor 6-diazo-5-oxo-L-norleucine [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 5267.

Actinomycin-D and dimethylamino-parthenolide synergism in treating human pancreatic cancer cells.

Preclinical Research & Development Pancreatic cancer is the third leading cause of death in the US with a poor 5-year survival rate of 8.5%. A novel anti-cancer drug, dimethylamino parthenolide (DMAPT), is the water-soluble analog of the natural sesquiterpene lactone, parthenolide. The putative modes of action of DMAPT are inhibition of the Nuclear chain factor kappa-light-chain enhancer of activated B cells (NFκB) pathway and depletion of glutathione levels; the latter causing cancer cells to be more susceptible to oxidative stress-induced cell death. Actinomycin-D (ActD) is a polypeptide antibiotic that binds to DNA, and inhibits RNA and protein synthesis by inhibiting RNA polymerase II. A phase 2 clinical trial indicated that ActD could be a potent drug against pancreatic cancer; however, it was not a favored drug due to toxicity issues. New drug entities and methods of drug delivery, used alone or in combination, are needed to treat pancreatic cancer more effectively. Thus, it was postulated that combining DMAPT and ActD would result in synergistic inhibition of Panc-1 pancreatic cancer cell growth because DMAPT's inhibition of NFκB would enhance induction of apoptosis by ActD, via phosphorylation of c-Jun, by minimizing NFκB inhibition of c-Jun phosphorylation. Combining these two drugs induced a higher level of cell death than each drug alone. A fixed drug ratio of DMAPT: ActD (1,200:1) was used. Data from metabolic (MTT) and colony formation assays were analyzed for synergism with CompuSyn software, which utilizes the Chou-Talalay equation. The analyses indicated synergism and moderate synergism at combination concentrations of DMAPT/ActD of 12/0.01 and 18/0.015 μM, respectively.