Activation of epidermal growth factor receptors in triple-negative breast cancer cells by morphine; analysis through Raman spectroscopy and machine learning.

Triple negative breast cancer (TNBC) is a very aggressive form of breast cancer, and the analgesic drug morphine has been shown to promote the proliferation of TNBC cells. This article investigates whether morphine causes activation of epidermal growth factor receptors (EGFR), the roles of µ-opioid and EGFR receptors on TNBC cell proliferation and migration. While examining the changes with molecular techniques, we also aimed to investigate the analysis ability of Raman spectroscopy and machine learning-based approach. Effects of morphine on the proliferation and migration of MDA.MB.231 cells were evaluated by MTT and scratch wound-healing tests, respectively. Morphine-induced phosphorylation of the EGFR was analyzed by western blotting in the presence and absence of µ-receptor antagonist naltrexone and the EGFR-tyrosine kinase inhibitor gefitinib. Morphine-induced EGFR phosphorylation and cell migration were significantly inhibited by pretreatments with both naltrexone and gefitinib; however, morphine-increased cell proliferation was inhibited only by naltrexone. While morphine-induced changes were observed in the Raman scatterings of the cells, the inhibitory effect of naltrexone was analyzed with similarity to the control group. Principal component analysis (PCA) of the Raman confirmed the epidermal growth factor (EGF)-like effect of morphine and was inhibited by naltrexone and partly by gefitinib pretreatments. Our in vitro results suggest that combining morphine with an EGFR inhibitor or a peripherally acting opioidergic receptor antagonist may be a good strategy for pain relief without triggering cancer proliferation and migration in TNBC patients. In addition, our results demonstrated the feasibility of the Raman spectroscopy and machine learning-based approach as an effective method to investigate the effects of agents in cancer cells without the need for complex and time-consuming sample preparation. The support vector machine (SVM) with linear kernel automatically classified the effects of drugs on cancer cells with ∼95% accuracy.

An evaluation of the effects on the ovaries of hyperbaric oxygen therapy in a rat model of premature ovarian failure created with cyclophosphamide.

Objective: To evaluate hyperbaric oxygen therapy (HBO) based on ovarian histology, total antioxidant status (TAS), total oxidant status (TOS), and anti-müllerian hormone (AMH), in the ovarian insufiency (POI) model created with cyclophosphamide (CYP). Materials and Methods: The rats were separated into 3 groups of the control group (n=6), the CYP group (n=6), and the CYP+HBO group (n=6). The rats in the CYP group and the CYP+HBO group were injected intraperitoneally with 200 mg/kg CYP on day 1, followed by 8 mg/kg/day for 14 days to create POI. From the 15th day onwards, the rats in the CYP+HBO group were placed in a hyperbaric cabin and exposed to 100% oxygen at 2.4 atm pressure for one h, and were then returned to their cages at the end of the hour. Results: A statistically significant decrease was determined in the primordial and primary follicle counts in the CYP group compared with the control group (p<0.05). In the CYP+HBO group, a statistically significant increase was determined in the primordial and primary follicle counts (p<0.05). The serum AMH levels were seen to be significantly decreased in the CYP group compared with both the control group and the CYP+HBO groups. The HBO was seen to decrease TOS and increase TAS. Conclusion: HBO could be an alternative treatment to minimize the effect of ovarian follicle loss caused by CYP, which is used for treating tumors that commonly occur in young females of reproductive age.

Morphine counteracts the effects of paclitaxel in triple-negative breast cancer cells.

Background & objectives: Several studies have provided evidence that opioids may play a role in cancer recurrence and metastasis. Multiple research data indicate that morphine can act as a proliferative or suppressive agent on tumour cells depending on the applied concentration. Therefore, this study was aimed to investigate whether the presence of clinically relevant concentrations of morphine has any effect on the efficacy of paclitaxel, a widely used chemotherapeutic drug, on the viability and apoptosis of human triple-negative breast cancer cell line. Methods: MDA.MB.231 cells were treated with paclitaxel in the presence or absence of morphine and examined for cell proliferation by the MTT assay. In addition, the effect of morphine on paclitaxel-induced apoptosis was investigated by flow cytometric assay and by the ratio of Bax/Bcl-2 mRNA expression levels with quantitative real-time (qRT)-PCR. Results: Morphine significantly increased the proliferation of breast cancer cells at low concentrations (0.1-2.5 µM) but higher concentrations showed cytotoxic effect. Pre-treatment with 0.1 or 1 µM of morphine decreased the paclitaxel-induced cytotoxicity, the proportion of apoptotic cell, and the ratio of Bax/Bcl-2 mRNA expressions. Interpretation & conclusions: Our data suggest that morphine promotes breast cancer cell viability at clinically relevant plasma concentrations and reduces the apoptotic effect of paclitaxel. This interaction may be very important in clinical settings; however, more studies are needed to explore the plausible mechanisms of interaction and to correlate such findings through in vivo animal studies as well as clinically.

Doxazosin and erlotinib have anticancer effects in the endometrial cancer cell and important roles in ERα and Wnt/ß-catenin signaling pathways.

ERα and Wnt/ß-catenin pathways are critical for the progression of most endometrial cancers. We aimed to investigate the cytotoxic and apoptotic effects of tamoxifen and quinazoline derivative drugs of doxazosin and erlotinib, and their roles in ERα and Wnt/ß-catenin signaling pathways in human endometrial cancer RL 95-2 cell. 3-(4,5-Dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide assay and xCELLigence systems were performed to evaluate cytotoxicity. Furthermore, apoptotic induction was tested by Annexin V analysis. Caspase-3 and -9 activity and changes in the mitochondrial membrane potential were evaluated. The level of reactive oxygen species was measured by incubating with dichlorofluorescein diacetate. Protein ratios of p-ERα/ERα, GSK3ß/p-GSK3ß, and p-ß-catenin/ß-catenin and expression levels of ESR1, EGFR, c-Myc genes were evaluated to elucidate mechanisms in signaling pathways. We found that the tested drugs showed cytotoxic and apoptotic effects in the cells. Doxazosin significantly reduced ESR1 expression, slightly reduced the p-ß-catenin/ß-catenin ratio and c-Myc expression. Erlotinib significantly increased c-Myc expression while significantly decreasing the p-ß-catenin/ß-catenin and p-ERα/ERα ratio, and ESR1 expression. However, we observed that the cells develop resistance to erlotinib over a certain concentration, suggesting that ERα, ESR1, EGFR, and c-Myc may be a new target for overcoming drug resistance in the treatment of endometrial cancer. We also observed that erlotinib and doxazosin play an important role in the ERα signaling pathway and can act as potent inhibitors of PKA and/or tyrosine kinase in the Wnt/ß-catenin signaling pathway in RL 95-2 cell. In conclusion, doxazosin and erlotinib may have a possible therapeutic potential in human endometrial cancer.

Synthesis, molecular modeling, in vivo study and anticancer activity against prostate cancer of (+) (S)-naproxen derivatives.

In this study, (S)-naproxen thiosemicarbazides (3a-d), 1,2,4-triazoles (4a-c), triazole-thioether hybride compounds (5a-p) were synthesized and their structures (3a, 3d, 4a and 5a-p) were confirmed by FT-IR, 1H NMR,13C NMR, HR-Mass spectra and elemental analysis. These compounds are designed to inhibit methionine amino peptidase-2 (MetAP2) enzyme in prostate cancer. These compounds (3d, 5a-p) evaluated against androgen-independent prostate adenocarcinoma (PC-3, DU-145) and androgen-dependent prostate adenocarcinoma (LNCaP) cell lines by using MTS method. Compounds 5a, 5b, 5d and 5e showed 14.2, 5.8, 10.8 and 8.4 µM anticancer activity against PC-3 cell lines, compounds 5e, 5g and 5n presented anticancer activity against DU-145 cell lines 18.8, 12.25 and 10.2 µM, and compounds 5g, 5m and 5n exhibited anticancer activity against LNCaP cell lines 12.25, 22.76 and 2.21 µM, respectively. Consequently, of these results, compounds 5e and 5n showed the highest activities against androgen dependent and independent prostate cancer cell lines, so these compounds could be potent small molecules against prostate cancer. Furthermore, mitogen-activated protein kinase (MAPK) pathway activation, AKT (protein kinase B) phosphorylation and androgen receptor activation of compound 5n (SGK636) were investigated in LNCaP cells by using Western blot method. Compound 5n (SGK636) was also tested against mRNA expression analysis of the Bax, Bcl-2, Caspase 3, Caspase 9 by using real-time PCR analysis. Compound 5n was given to nude male mice with cancer in comparison to the control group. Compound 5n was found to reverse the malignant phenotype in the nude male mice, whereas the prostate cancer progressed in the control group. Analysis of some blood parameters in the study showed that they were within the normal values with respect to the control. The blood values of the animals treated according to the control group also exhibited compliance with the blood limit values. Molecular docking and dynamics simulation of compound 5n binding to Methionine Aminopeptidase 2 (MetAP2) enzyme rationalized its potential activity. In addition, inhibition assay MetAP2 enzyme of compound 5n was evaluated. Taken together, we suggest compound 5n to be a potential candidate for prostate cancer therapy.

Synthesis, Anticancer Activity on Prostate Cancer Cell Lines and Molecular Modeling Studies of Flurbiprofen-Thioether Derivatives as Potential Target of MetAP (Type II).

BACKGROUND: Prostate cancer is still one of the serious causes of mortality and morbidity in men. Despite recent advances in anticancer therapy, there is a still need of novel agents with more efficacy and specificity in the treatment of prostate cancer. Because of its function on angiogenesis and overexpression in the prostate cancer, methionine aminopeptidase-2 (MetAP-2) has been a potential target for novel drug design recently. OBJECTIVE: A novel series of Flurbiprofen derivatives N-(substituted)-2-(2-(2-fluoro-[1,1'- biphenyl]-4-il)propanoyl)hydrazinocarbothioamide (3a-c), 4-substituted-3-(1-(2-fluoro-[1,1'-biphenyl]- 4-yl)ethyl)-1H-1,2,4-triazole-5(4H)-thione (4a-d), 3-(substitutedthio)-4-(substituted-phenyl)- 5-(1-(2-fluoro-[1,1'-biphenyl]-4-yl)ethyl)-4H-1,2,4-triazole (5a-y) were synthesized. The purpose of the research was to evaluate these derivatives against MetAP-2 in vitro and in silico to obtain novel specific and effective anticancer agents against prostate cancer. METHODS: The chemical structures and purities of the compounds were defined by spectral methods (1H-NMR, 13C-NMR, HR-MS and FT-IR) and elemental analysis. Anticancer activities of the compounds were evaluated in vitro by using MTS method against PC-3 and DU-143 (androgenindependent human prostate cancer cell lines) and LNCaP (androgen-sensitive human prostate adenocarcinoma) prostate cancer cell lines. Cisplatin was used as a positive sensitivity reference standard. RESULTS: Compounds 5b and 5u; 3c, 5b and 5y; 4d and 5o showed the most potent biological activity against PC3 cancer cell line (IC50= 27.1 µM, and 5.12 µM, respectively), DU-145 cancer cell line (IC50= 11.55 µM, 6.9 µM and 9.54 µM, respectively) and LNCaP cancer cell line (IC50= 11.45 µM and 26.91 µM, respectively). Some compounds were evaluated for their apoptotic caspases protein expression (EGFR/PI3K/AKT pathway) by Western blot analysis in androgen independent- PC3 cells. BAX, caspase 9, caspsase 3 and anti-apoptotic BcL-2 mRNA levels of some compounds were also investigated. In addition, molecular modeling studies of the compounds on MetAP-2 enzyme active site were evaluated in order to get insight into binding mode and energy. CONCLUSION: A series of Flurbiprofen-thioether derivatives were synthesized. This study presented that some of the synthesized compounds have remarkable anticancer and apoptotic activities against prostate cancer cells. Also, molecular modeling studies exhibited that there is a correlation between molecular modeling and anticancer activity results.

Synthesis of gold and silver nanoparticles using flavonoid quercetin and their effects on lipopolysaccharide induced inflammatory response in microglial cells.

Quercetin is a plant origin phytochemical with several pharmaceutical activities such as antioxidant, immunomodulatory, and anti-inflammatory effects. However, consumption of quercetin is limited due to its low aqueous solubility and poor bioavailability. The aim of the present study was to synthesize silver and gold nanoparticles of quercetin with a view to improve its aqueous phase solubility and investigate the effects on LPS-induced neuroinflammation in BV-2 microglial cells. The average size of silver and gold-quercetin nanoparticles was 53 and 27 nm, respectively. Absorption peaks in the UV-Vis spectra were observed at 555 and 405 nm for gold and silver-quercetin nanoparticles, respectively. The particle size and mapping of silver and gold-quercetin nanoparticles were also determined using a STEM detector. The inflammatory stimulation of the BV-2 cells with LPS caused an elevated release of proinflammatory prostaglandin, E2, nitric oxide (NO), upregulated cyclooxygenase-2, inducible NO synthase mRNA, and protein levels, which were markedly inhibited by the pretreatment with gold-quercetin nanoparticles (highly soluble in water) without causing any cytotoxic effects. The findings of the present study suggest that the potential of gold-quercetin nanoparticles are much better than quercetin and that gold-quercetin nanoparticles might provide protection against inflammatory neurodegenerative disease via suppression of acute microglial activation.

Synthesis, molecular modeling, in vivo study, and anticancer activity of 1,2,4-triazole containing hydrazide-hydrazones derived from (S)-naproxen.

A new series of 1,2,4-triazole containing hydrazide-hydrazones derived from (S)-naproxen ( 7a-m) was synthesized in this study. The structures of these compounds were characterized by spectral (Fourier-transform infrared spectroscopy, 1 H-nuclear magnetic resonance (NMR), 13 C-NMR, and high-resolution electron ionization mass spectrometry) methods. Furthermore, molecular modeling of these compounds was studied on human methionine aminopeptidase-2. All synthesized compounds were screened for anticancer activity against three prostate cancer cell lines (PC3, DU-145, and LNCaP) using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium colorimetric method. Compound 7a showed the best activity against the PC3, DU-145 and LNCaP cancer cell lines with IC50 values of 26.0, 34.5, and 48.8 µM, respectively. Compounds 7b, 7k, and 7m showed anticancer activity against cancer cell lines PC3 and DU-145 with IC50 values of 43.0, 36.5, 29.3 µM and 49.8, 49.1, 31.6 µM, respectively. Compounds 7f and 7g showed anticancer activity against PC3 cells with IC50 values of 43.4 and 34.5 µM, respectively. To assess the biodistribution in mice of IRDye800, dye-labeled compound 7a or 100 µM of free dye was injected intravenously into the mice's tail. In vivo images were taken with in vivo imaging system spectrum device at 60, 120, 180, 240, 300, and 360 min after injection. At the end of 360 min, ex vivo studies were carried out to determine in which organs the dye was accumulated in the urogenital system. Ex vivo studies showed that the accumulation of compound 7a in the prostate is greater than that of the free dye, and it is concluded that compound 7a may be promising for the treatment of prostate cancer.

Effect of the Lipid Peroxidation Product 4-Hydroxynonenal on Neuroinflammation in Microglial Cells: Protective Role of Quercetin and Monochloropivaloylquercetin.

OBJECTIVES: The lipid peroxidation-derived aldehyde 4-hydroxynonenal (HNE) has been implicated in a number of oxidative stress-induced inflammatory pathologies such as neurodegenerative diseases and aging. In this regard, we investigated the effects of HNE on neuroinflammatory responses by measuring cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) induction with cytokine production. In addition, we measured nuclear factor erythroid 2-related factor 2 (Nrf-2)/Kelch-like ECH-associated protein 1 (Keap1) signaling proteins, and antioxidant enzymes heme oxygenase-1 (HO-1) and nicotinamide adenine dinucleotide phosphate dehydrogenase, quinone 1 (NQO1), and compared the results with quercetin and monochloropivaloylquercetin (MPQ) pretreated microglial cells. MATERIALS AND METHODS: Cytotoxicity was determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and production of cytokines was determined by cytokine array. Furthermore, intracellular Nfr2/Keap1 signaling proteins, HO-1, NQO1, and COX-2 expression were analyzed by western blot in 2.5 µM HNE treated BV-2 cells. RESULTS: Inducible nitric oxide synthase (iNOS) and COX-2 mRNA levels were measured with reverse transcription-quantitative polymerase chain reaction. HNE induced both COX-2 mRNA and protein levels, iNOS mRNA expression, and cytokine production. In addition, HNE markedly increased Keap1 levels and decreased cytoplasmic Nrf-2 expression with antioxidant enzyme HO-1 levels. Quercetin and monochloropivaloylquercetin treatment alleviated neuroinflammatory responses in microglial cells, by decreasing COX-2 mRNA expression. Monochloropivaloylquercetin decreased cytoplasmic Keap1 levels and increased nuclear translocation of Nrf-2 resulted in induction of HO-1 and NQO1 expression. CONCLUSION: These results suggest that HNE could be a link between oxidative stress and inflammation in BV-2 microglia cells. In particular, monochloropivaloylquercetin alleviated inflammation, probably by decreasing the expression of proinflammatory genes and strengthening the antioxidant defense system.

Anti-inflammatory Effects of Pelargonium endlicherianum Fenzl. Extracts in Lipopolysaccharide-stimulated Macrophages.

OBJECTIVES: This study was designed to investigate the anti-inflammatory effects of Pelargonium endlicherianum Fenzl. and Pelargonium quercetorum Agnew. root extracts compared with the effects of commercial Pelargonium sidoides root extract by production of pro-inflammatory substances and inflammatory signal transduction on LPS-stimulated macrophages. MATERIALS AND METHODS: To measure the effects of root extracts on pro-inflammatory mediators, we used the following methods: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (cell viability or cytotoxcicity), enzyme-linked immunosorbent assay (cytokine production, prostoglandin E2 production), reverse transcriptase-polymerase chain reaction (COX-2, iNOS mRNA), Western blotting analysis [MAPK activation and NF-κB (p65) traslocation] and the Griess reaction (NO production). RESULTS: Stimulation of the RAW 264.7 cells with LPS (0.5 µg/mL, 6 hrs treatment) caused an elevated production of pro-inflammatory cytokines (TNF-α and IL-6), increased mRNA expression of COX-2 and inducible NO synthase with release of PGE2 and NO, activated MAPK (phosphorylation of c-Jun N-terminal kinase, extracellular signal-regulated kinase, P38) signalling pathway, and nuclear translocation of NF-κB (p65), which were markedly inhibited by the pre-treatment with 11% ethanol and 70% methanol root extracts of P. endlicherianum without causing any cytotoxic effects. P. quercetorum root extract only decreased TNF-α production and P. sidoides root extract alleviated P38/MAPK activation and COX-2 mRNA expression with PGE2 production. CONCLUSION: Our data indicate that especially 11% ethanol root extract of P. endlicherianum targets the inflammatory response of macrophages via inhibition of COX-2, IL-6, and TNF-α through inactivation of the NF-κB signalling pathway, supporting the pharmacologic basis of P. endlicherianum as a traditional herbal medicine for the treatment of inflammation and its associated disorders.

Synthesis and pro-apoptotic effects of new sulfonamide derivatives via activating p38/ERK phosphorylation in cancer cells.

Herein, the compounds bearing sulfonamide fragment such as N-(2-amino-5-benzoylphenyl)-4-nitrobenzene sulfonamide hydrochloride (1), N-(quinolin-8-yl)-4-nitro-benzenesulfonamide hydrochloride (2), N-(pyridine-2-ylmethyl)-4-nitro-benzenesulfonamide hydrochloride (3) were synthesized by the reaction of 3,4-diaminobenzophenone, 8-aminoquinoline or 2-picoylamine and 4-nitrobenzensulfonyl chloride, respectively. The structures of the newly synthesized compounds were elucidated on the basis of elemental and spectral analyses. All the prepared compounds were evaluated for their in vitro anti-cancer activity against various cancer cell lines and to explore the underlying molecular mechanisms involved in this process. In vitro cytotoxic activities of the compounds were screened against human hepatocellular (HepG2), breast (MCF-7) and colon (Colo-205) cancer cell lines by MTT assay, mRNA expression of genes with qPCR and phosphorylation of p38 and ERK1/2 with Western blot. Tested compounds could significantly reduce cell proliferation and induced mRNA expression of pro-apoptotic genes; caspase 3, caspase 8 and caspase 9. Activation of these apoptotic genes probably is mediated by activation of p38.

Redox status related activation of endoplasmic reticulum stress and apoptosis caused by 4-hydroxynonenal exposure in INS-1 cells.

4-Hydroxynonenal (HNE), a diffusible aldehyde product of membrane lipid peroxidation, can be produced by oxidative stress and has been detected in several diseases such as diabetes. In this study, we investigated the effects of HNE exposure on cytotoxicity, intracellular redox status, endoplasmic reticulum (ER) stress and apoptosis in insulinoma cell line (INS-1). Short-term (1 h) incubation of INS-1 cells with 0-50 µM HNE decreased cell viability and caused depletion in reduced glutathione (GSH) levels and increased intracellular HNE-histidine adducts in a concentration-dependent manner. HNE activated the ER stress, leading to an increase in inositol-requiring enzyme-1a IRE1-α, phosphorylation of protein kinase-like ER kinase, phosphorylation of c-Jun N-terminal kinase (JNK) and increased the expression of CCAAT/enhancer binding protein (CHOP). Western blot analysis showed that HNE exposure induced dose-dependent activation of caspase 9 and caspase 3. These data indicate a potential role for HNE promoting deleterious effects toward pancreatic beta cell redox status and beta cell mass which may be important for the pathogenesis in diabetes.

Effects of ketamine, propofol, and ketofol on proinflammatory cytokines and markers of oxidative stress in a rat model of endotoxemia-induced acute lung injury.

Intravenous lipopolysaccharide (LPS) leads to acute lung injury (ALI) in rats. The purpose of this study was to examine the anti-inflammatory and antioxidant efficacy of ketamine, propofol, and ketofol in a rat model of ALI. We induced ALI in rats via intravenous injection of LPS (15 mg kg(-1)). The animals were randomly separated into five groups: control, LPS only, LPS + ketamine (10 mg·kg(-1)·h(-1)), LPS + propofol (10 mg·kg(-1)·h(-1)), LPS + ketofol (5 mg·kg(-1)·h(-1) ketamine + 5 mg·kg(-1)·h(-1) propofol). LPS resulted in an increase in the release of pro-inflammatory cytokines, mRNA expression related with inflammation, production of nitric oxide, and lipid peroxidation. Ketamine prevented the increase in markers of oxidative stress and inflammation mediators, both in plasma and lung tissue. Propofol decreased the levels of cytokines in plasma and lung tissue, whereas it had no effect on the IL-1-beta level in lung tissue. Ketamine downregulated mediators of lung tissue inflammation and reduced the level of circulating cytokines and protected lung tissue against lipid peroxidation. Ketofol decreased the level of TNF-α and IL-1ß in plasma, as well as expression of cyclooxygenase-2 mRNA and the nitrate/nitrite level in lung tissue. The results of this investigation support the hypothesis that ketamine may be effective in preventing ALI.

Age- and diabetes-induced regulation of oxidative protein modification in rat brain and peripheral tissues: consequences of treatment with antioxidant pyridoindole.

The increased glyco- and lipo-oxidation events are considered one of the major factors in the accumulation of non-functional damaged proteins, and the antioxidants may inhibit extensive protein modification and nitrosylated protein levels, enhancing the oxidative damage at the cellular levels in aging and diabetes. Because of its central role in the pathogenesis of age-dependent and diabetes-mediated functional decline, we compared the levels of oxidatively modified protein markers, namely AGEs (Advanced Glycation End-protein adducts), 4-HNE (4-hydroxy-nonenal-histidine) and 3-NT (3-nitrotyrosine), in different tissues of young and old rats. Separately, these three oxidative stress parameters were explored in old rats subjected to experimentally induced diabetes and following a long-term treatment with a novel synthetic pyridoindole antioxidant derived from stobadine-SMe1EC2 (2-ethoxycarbonyl-8-methoxy-2,3,4,4a,5,9b-hexahydro-1H-pyrido[4,3-b]indolinium dichloride). Diabetes induced by streptozotocin injection in rats aged 13-15 months, and SMe1EC2 treatment was applied during 4months to aged diabetic rats. AGEs and 4-HNE levels were significantly elevated in brain, ventricle and kidney, but not in lens and liver of aged rats when compared with young rats. Diabetes propagated ageing-induced increase in AGEs and 4-HNE in brain, ventricle and kidney, and raised significantly lens and liver AGEs and 4-HNE levels in aged rats. In aged diabetic rats, SMe1EC2 protected only the kidney against increase in AGEs, and inhibited significantly 4-HNE levels in brain, kidney, liver and lens that were observed more pronounced in lens. 3-NT was significantly increased in brain of aged rats and in kidney, lens and ventricle of aged diabetic rats, while SMe1EC2 has no protective effect on 3-NT increase. Results demonstrate that (1) the responsiveness of different tissue proteins to glyco-lipo-oxidative and nitrosative stress in the course of normal aging was miscellaneous. (2) Diabetes is a major factor contributing to accelerated aging. (3) SMe1EC2 selectively inhibited the generation of oxidatively modified proteins, only in a limited number of tissues.

Aldose reductase inhibitory activity and antioxidant capacity of pomegranate extracts.

The pomegranate, Punica granatum L., has been the subject of current interest as a medicinal agent with wide-ranging therapeutic indications. In the present study, pomegranate ethanolic seed and hull extracts were tested, in comparison with a commercial sample, for the inhibition of aldose reductase, an enzyme involved in the etiology of diabetic complications. In vitro inhibition of rat lens aldose reductase was determined by a conventional method. Pomegranate ethanolic hull extract and commercial pomegranate hull extract exhibited similar aldose reductase inhibitory activity characterized by IC(50) values ranging from 3 to 33.3 µg/ml. They were more effective than pomegranate ethanolic seed extract with IC(50) ranging from 33.3 to 333 µg/ml. Antioxidant action of the novel compounds was documented in a DPPH test and in a liposomal membrane model, oxidatively stressed by peroxyl radicals. All the plant extracts showed considerable antioxidant potential in the DPPH assay. Pomegranate ethanolic hull extract and commercial pomegranate hull extract executed similar protective effects on peroxidatively damaged liposomal membranes characterized by 10

Investigation of ocular neovascularization-related genes and oxidative stress in diabetic rat eye tissues after resveratrol treatment.

Changes in vascular endothelial growth factor (VEGF), angiotensin-converting enzyme (ACE), matrix metalloproteinase (MMP)-9, and endothelial nitric oxide synthase (eNOS) mRNA expression profiles and oxidative stress in the eye tissue microenviroment may have important roles in ocular neovascularization and permeability in proliferative diabetic retinopathy. The present study investigated the effects of resveratrol (RSV) treatment on the mRNA expression profile of VEGF, ACE, MMP-9, and eNOS, which are associated with vascular neovascularization, and glutathione, protein carbonyl, and nitrite-nitrate levels, which are markers of oxidative stress in eyes of diabetic rats. Twenty-four Wistar albino male rats were divided into four groups. After diabetes induction with streptozotocin (10 mg/kg/day) RSV was administered to the RSV and diabetes mellitus (DM) + RSV groups for 4 weeks. The mRNA levels were measured by quantitative real-time polymerase chain reaction assay, and biochemical estimations were determined with spectrophotometric assays in eye homogenates. The mRNA expression levels of VEGF, ACE, and MMP-9 were increased in the DM group compared with the control group, and RSV treatment decreased their mRNA levels. Expression of eNOS mRNA was increased in the RSV and DM groups and decreased in the DM + RSV group. Nitrite-nitrate levels and protein carbonyl content were increased and glutathione levels were decreased in the DM group compared with controls. Consequently, these data suggest that RSV suppressed the expression of eNOS, which is actively involved in the inflammation and healing process in chronic diabetes. Although oxidative stress was increased in eye tissue from diabetic rats, mRNA levels of VEGF, MMP-9, and ACE genes associated with vascular remodeling did not change in diabetic eyes.

Polyphenolic extracts from Olea europea L. protect against cytokine-induced ß-cell damage through maintenance of redox homeostasis.

Various pancreatic ß-cell stressors, including cytokines, are known to induce oxidative stress, resulting in apoptotic/necrotic cell death and inhibition of insulin secretion. Traditionally, olive leaves or fruits are used for treating diabetes, but the cellular mechanism(s) of their effects are not known. We examined the effects of Olea europea L. (olive) leaf and fruit extracts and their component oleuropein on cytokine-induced ß-cell toxicity. INS-1, an insulin-producing ß-cell line, was preincubated with or without increasing concentrations of olive leaf or fruit extract or oleuropein for 24 hr followed by exposure to a cytokine cocktail containing 0.15 ng/mL interleukin-1ß (IL-1ß), 1 ng/mL interferon-γ (IFN-γ), and 1 ng/mL tumor necrosis factor-α (TNF-α) for 6 hr. The cytotoxicity was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) testing. Apoptosis was quantified by detecting acridine orange/ethidium bromide-stained condensed nuclei under a fluorescent microscope. The cells exposed to cytokines had a higher apoptotic rate, a decreased viability (MTT), and an increased caspase 3/7 activity. Both extracts and oleuropein partially increased the proportion of living cells and improved the viability of cells after cytokines. The protective effects of extracts on live cell viability were mediated through the suppression of caspase 3/7 activity. Oleuropein did not decrease the amount of both apoptotic and necrotic cells, whereas extracts significantly protected cells against cytokine-induced death. Cytokines led to an increase in reactive oxygen species (ROS) generation and inhibited glutathione level, superoxide dismutase activity, and insulin secretion in INS-1. Insulin secretion was almost completely protected by leaf extract, but was partially affected by fruit extract or oleuropein. Neither cytokines nor olive derivatives had a significant effect on cellular cytochrome c release and catalase activity. Moreover, the cells incubated with each extract or oleuropein showed a significant reduction in cytokine-induced ROS production and ameliorated abnormal antioxidant defense. The molecular mechanism by which olive polyphenols inhibit cytokine-mediated ß-cell toxicity appears to be involving the maintenance of redox homeostasis.

Effects of olive leaf polyphenols against H2O2 toxicity in insulin secreting ß-cells.

In pancreatic ß-cells, although H2O2 is a metabolic signal for glucose stimulated insulin secretion, it may induce injury in the presence of increased oxidative stress (OS) as in the case of diabetic chronic hyperglycemia. Olea europea L. (olive) leaves contain polyphenolic compounds that may protect insulin-secreting cells against OS. The major polyphenolic compound in ethanolic olive leaf extract (OLE) is oleuropein (about 20%), thus we compared the effects of OLE with the effects of standard oleuropein on INS-1 cells. The cells were incubated with increasing concentrations of OLE or oleuropein for 24 h followed by exposure to H2O2 (0.035 mM) for 45 min. H2O2 alone resulted in a significantly decreased viability (MTT assay), depressed glucose-stimulated insulin secretion, increased apoptotic and necrotic cell death (AO/EB staining), inhibited glutathione peroxidase activity (GPx) and stimulated catalase activity that were associated with increased intracellular generation of reactive oxygen species (ROS) (fluorescence DCF). OLE and oleuropein partly improved the viability, attenuated necrotic and apoptotic death, inhibited the ROS generation and improved insulin secretion in H2O2-exposed cells. The effects of oleuropein on insulin secretion were more pronounced than those of OLE, while OLE exerted a stronger anti-cytotoxic effect than oleuropein. Unlike OLE, oleuropein had no significant preserving effect on GPx; however, both compounds stimulated the activity of catalase in H2O2-exposed cells. These findings indicate different modulatory roles of polyphenolic constituents of olive leaves on redox homeostasis that may have a role in the maintenance of ß-cell physiology against OS.

Novel hexahydropyridoindole derivative as prospective agent against oxidative damage in pancreatic ß cells.

The potential protective effect of (±)-8-methoxy-1,3,4,4a,5,9b-hexahydro-pyrido[4,3-b]indole-2-carboxylic acid ethyl ester (II) was assessed against hydrogen peroxide (H2O2)-cytotoxicity in rat pancreatic INS-1E ß cells and compared with the effect of the related pyridoindole, stobadine (I), a promising indole-type reference antioxidant. Only pre-treatment with the compound (II) led to a significant preservation of the metabolic and secretory functions of the cells exposed to H2O2. The caspase-9 and -3 activities, as well as the early apoptotic changes of plasma membrane, were suppressed in the cells pre-incubated with both of compounds tested. However, only pyridoindole (II) inhibited profoundly the time-delayed apoptotic changes, These results suggest that pyridoindole (II) characterized by enhanced intrinsic antioxidant efficiency, may protect ß cells against cytotoxic effects of H2O2, involved in the development of both type 1 and type 2 diabetes.

Effect of long term, non cholesterol lowering dose of fluvastatin treatment on oxidative stress in brain and peripheral tissues of streptozotocin-diabetic rats.

One of the main goals of treatment of diabetes mellitus is to prevent its complications. Oxidative stress is universal in diabetes, being ultimately involved with the development complications. As a result of hyperglycemia, reactive oxygen/nitrogen species are produced in various tissues that leads to tissue damage with lipid peroxidation and protein oxidation, along with disruption in cellular homeostasis and accumulation of damaged molecules. Hence, supplementation with antioxidant compounds may offer some protection against diabetic complications. The pleiotropic effects of statins, including antioxidant and anti-inflammatory properties, represent an area of great interest in prevention and therapy of cardiovascular and neurological disorders. Using biomarkers of oxidative stress, in this study we examined the effect of non cholesterol lowering dose, long term fluvastatin treatment on oxidative stress in streptozotocin-diabetic rats. Experiments were conducted in 24 Wistar adult male rats. Diabetic and non-diabetic rats were treated orally for 6 months with fluvastatin (2mg/kg/day, p.o) starting one week after streptozotocin injection (55 mg/kg, i.p.), (preventive study). In brain, heart, liver, pancreas and kidney homogenates malondialdehyde, lipid hydroperoxide, protein carbonyl content, advanced oxidation protein products, 3-nitrotyrosine levels and superoxide dismutase, catalase activities were measured. Hyperglycemia and dyslipidemia in diabetic groups remained unchanged after fluvastatin treatment. The drug act as antioxidant in the tissues. Hence, antioxidant property of fluvastatin, independent of cholesterol lowering effect, may play a role in prevention of diabetic complications. Clinical relevance of this effect of fluvastatin seems worthy of further studies.