MTHFD2 Blockade Enhances the Efficacy of β-Lapachone Chemotherapy With Ionizing Radiation in Head and Neck Squamous Cell Cancer

Head and Neck Squamous Cell Cancer (HNSCC) presents with multiple treatment challenges limiting overall survival rates and affecting patients' quality of life. Amongst these, resistance to radiation therapy constitutes a major clinical problem in HNSCC patients compounded by origin, location, and tumor grade that limit tumor control. While cisplatin is considered the standard radiosensitizing agent for definitive or adjuvant radiotherapy, in recurrent tumors or for palliative care other chemotherapeutics such as the antifolates methotrexate or pemetrexed are also being utilized as radiosensitizers. These drugs inhibit the enzyme dihydrofolate reductase, which is essential for DNA synthesis and connects the 1-C/folate metabolism to NAD(P)H and NAD(P)+ balance in cells. In previous studies, we identified MTHFD2, a mitochondrial enzyme involved in folate metabolism, as a key contributor to NAD(P)H levels in the radiation-resistant cells and HNSCC tumors. In the study presented here, we investigated the role of MTHFD2 in the response to radiation alone and in combination with β-lapachone, a NQO1 bioactivatable drug, which generates reactive oxygen species concomitant with NAD(P)H oxidation to NAD(P)+. These studies are performed in a matched HNSCC cell model of response to radiation: the radiation resistant rSCC-61 and radiation sensitive SCC-61 cells reported earlier by our group. Radiation resistant rSCC-61 cells had increased sensitivity to β-lapachone compared to SCC-61 and knockdown of MTHFD2 in rSCC-61 cells further potentiated the cytotoxicity of β-lapachone with radiation in a dose and time-dependent manner. rSCC-61 MTHFD2 knockdown cells irradiated and treated with β-lapachone showed increased PARP1 activation, inhibition of mitochondrial respiration, decreased respiration-linked ATP production, and increased mitochondrial superoxide and protein oxidation as compared to control rSCC-61 scrambled shRNA. Thus, these studies point to MTHFD2 as a potential target for development of radiosensitizing chemotherapeutics and potentiator of β-lapachone cytotoxicity

Hypolipidemic and antioxidant activity of aqueous extract of fruit of <i>Withania coagulans </i><span style="mso-bidi-font-style: italic">(Stocks) Dunal<i> </i>in cholesterol-fed hyperlipidemic rabbit model </span>

870-875Withania coagulans (family: <i style="mso-bidi-font-style: normal">Solanaceae, English: Indian Cheese Maker, Hindi: Doda Paneer) fruit is known for its ethanopharmacological significance in health care system of India. Diet rich in high-fat is an important risk factor for diabetes, atherosclerosis and macro and microvascular complications. Treatment with aqueous extract of fruit of W. coagulans (aqWC; 250 mg/kg body weight) in cholesterol-fed animals resulted in significant decrease in the levels of total cholesterol, triacylglycerol, low density lipoprotein, tissue lipid content and acetyl CoA carboxylase activity whereas, the level of high density lipoprotein and activity of HMGCoA reductase also recovered partially. Treatment with aqWC also significantly decreased plasma lipid peroxide levels and increased reduced glutathione and superoxide dismutase activities. These results suggest that the aqueous extract of W. coagulans has potent lipid lowering and antioxidant activities

Aspalatone Prevents VEGF-Induced Lipid Peroxidation, Migration, Tube Formation, and Dysfunction of Human Aortic Endothelial Cells

Although aspalatone (acetylsalicylic acid maltol ester) is recognized as an antithrombotic agent with antioxidative and antiplatelet potential; its efficacy in preventing endothelial dysfunction is not known. In this study, we examined the antiangiogenic, antioxidative, and anti-inflammatory effect of aspalatone in human aortic endothelial cells (HAECs). Specifically, the effect of aspalatone on VEGF-induced HAECs growth, migration, tube formation, and levels of lipid peroxidation-derived malondialdehyde (MDA) was examined. Our results indicate that the treatment of HAECs with aspalatone decreased VEGF-induced cell migration, tube formation, and levels of MDA. Aspalatone also inhibited VEGF-induced decrease in the expression of eNOS and increase in the expression of iNOS, ICAM-1, and VCAM-1. Aspalatone also prevented the VEGF-induced adhesion of monocytes to endothelial cells. Furthermore, aspalatone also prevented VEGF-induced release of inflammatory markers such as Angiopoietin-2, Leptin, EGF, G-CSF, HB-EGF, and HGF in HAECs. Thus, our results suggest that aspalatone could be used to prevent endothelial dysfunction, an important process in the pathophysiology of cardiovascular diseases

Hepatoprotective effect of stem of Musa sapientum Linn in rats intoxicated with carbon tetrachloride

Methods. The study was designed to evaluate the hepatoprotective activity of aqueous extract of central stem of Musa sapientum (AqMS) against carbon tetrachloride induced hepatotoxicity in rats. Animals were divided into six groups. Group I served as normal control. Group II, III, IV, V &amp; VI were administered CCl4 mixed with olive oil 1:1 (1.5 mL/kg) I.P., twice a week for 5 weeks. Group II was maintained as CCl4 intoxicated control. Group III, IV and V received AqMS at a dose of 25, 50 and 100 mg/kg. Group VI received silymarin 100 mg/kg for 5 weeks orally once daily. Marker enzymes of hepatic functions estimated in serum were AST, ALT and ALP. Antioxidant parameters estimated were MDA and GSH in blood and liver and SOD in blood, after fifth week, animals were sacrificed, livers dissected out and evaluated for histomorphological changes.Results. There was significant rise in AST, ALT and ALP in CCl4 intoxicated control group II. Treatment with AqMS prevented rise in levels of these enzymes. There was significant rise in MDA and fall in GSH in blood and liver in group II, indicating increased lipid peroxidation and oxidative stress upon CCl4 ad-ministration. Treatment with AqMS prevented rise in MDA &amp; increased GSH in treated group. SOD levels were decreased in group II while groups treated with AqMS showed significant rise (p < 0.05). Maximum hepatoprotective effect was observed with 50 mg/kg dose. Hepatoprotective effect observed with this dose was comparable to standard hepatoprotective drug silymarin. The results of pathological study also support the results of biochemical findings.Conclusion. the results of the present study indicate that stem of Musa sapientum possess hepatoprotective effect and probably it is due to it’s antioxidant property

Vialinin A, an Edible Mushroom-Derived p-Terphenyl Antioxidant, Prevents VEGF-Induced Neovascularization In Vitro and In Vivo

Increased side toxicities and development of drug resistance are the major concern for the cancer chemotherapy using synthetic drugs. Therefore, identification of novel natural antioxidants with potential therapeutic efficacies is important. In the present study, we have examined how the antioxidant and anti-inflammatory activities of vialinin A, a p-terphenyl compound derived from Chinese edible mushroom T. terrestris and T. vialis, prevents human umbilical vascular endothelial cell (HUVEC) neovascularization in vitro and in vivo models. Pretreatment of HUVECs with vialinin A prevents vascular endothelial growth factor- (VEGF) induced HUVEC cell growth in a dose-dependent manner. Further, vialinin A also inhibits VEGF-induced migration as well as tube formation of HUVECs. Treatment of HUVECs prevents VEGF-induced generation of reactive oxygen species (ROS) and malondialdehyde (MDA) and also inhibits VEGF-induced NF-κB nuclear translocation as well as DNA-binding activity. The VEGF-induced release of various angiogenic cytokines and chemokines in HUVECs was also significantly blunted by vialinin A. Most importantly, in a mouse model of Matrigel plug assay, vialinin A prevents the formation of new blood vessels and the expression of CD31 and vWF. Thus, our results indicate a novel role of vialinin A in the prevention of neovascularization and suggest that anticancer effects of vialinin A could be mediated through its potent antioxidant and antiangiogenic properties

Aldose Reductase Inhibitor Protects against Hyperglycemic Stress by Activating Nrf2-Dependent Antioxidant Proteins

We have shown earlier that pretreatment of cultured cells with aldose reductase (AR) inhibitors prevents hyperglycemia-induced mitogenic and proinflammatory responses. However, the effects of AR inhibitors on Nrf2-mediated anti-inflammatory responses have not been elucidated yet. We have investigated how AR inhibitor fidarestat protects high glucose- (HG-) induced cell viability changes by increasing the expression of Nrf2 and its dependent phase II antioxidant enzymes. Fidarestat pretreatment prevents HG (25 mM)-induced Thp1 monocyte viability. Further, treatment of Thp1 monocytes with fidarestat caused a time-dependent increase in the expression as well as the DNA-binding activity of Nrf2. In addition, fidarestat augmented the HG-induced Nrf2 expression and activity and also upregulated the expression of Nrf2-dependent proteins such as hemeoxygenase-1 (HO1) and NQO1 in Thp1 cells. Similarly, treatment with AR inhibitor also induced the expression of Nrf2 and HO1 in STZ-induced diabetic mice heart and kidney tissues. Further, AR inhibition increased the HG-induced expression of antioxidant enzymes such as SOD and catalase and activation of AMPK-α1 in Thp1 cells. Our results thus suggest that pretreatment with AR inhibitor prepares the monocytes against hyperglycemic stress by overexpressing the Nrf2-dependent antioxidative proteins