Targeting Lipid Peroxidation for Cancer Treatment.

Cancer is one of the highest prevalent diseases in humans. The chances of surviving cancer and its prognosis are very dependent on the affected tissue, body location, and stage at which the disease is diagnosed. Researchers and pharmaceutical companies worldwide are pursuing many attempts to look for compounds to treat this malignancy. Most of the current strategies to fight cancer implicate the use of compounds acting on DNA damage checkpoints, non-receptor tyrosine kinases activities, regulators of the hedgehog signaling pathways, and metabolic adaptations placed in cancer. In the last decade, the finding of a lipid peroxidation increase linked to 15-lipoxygenases isoform 1 (15-LOX-1) activity stimulation has been found in specific successful treatments against cancer. This discovery contrasts with the production of other lipid oxidation signatures generated by stimulation of other lipoxygenases such as 5-LOX and 12-LOX, and cyclooxygenase (COX-2) activities, which have been suggested as cancer biomarkers and which inhibitors present anti-tumoral and antiproliferative activities. These findings support the previously proposed role of lipid hydroperoxides and their metabolites as cancer cell mediators. Depletion or promotion of lipid peroxidation is generally related to a specific production source associated with a cancer stage or tissue in which cancer originates. This review highlights the potential therapeutical use of chemical derivatives to stimulate or block specific cellular routes to generate lipid hydroperoxides to treat this disease.

Interfacial performance of gallic acid and methyl gallate accompanied by lecithin in inhibiting bulk phase oil peroxidation.

From an interfacial phenomena standpoint, gallic acid (GA), methyl gallate (MG), and their combination alone and together with lecithin (L) were evaluated for their inhibition against the formation of lipid hydroperoxides and carbonyl compounds in a stripped sunflower oil. Lecithin at a level (500 ppm) lower than its critical micelle concentration was able to protect the lipid system to some extent. GA (log P = -0.21), which was of higher capacity than MG (log P = - 0.14) in donating H/e- (IC50 = 36.4 vs. 39.9 µM and FRAP value = 598 vs. 514 µmol/L, respectively), exerted an antioxidant activity significantly better than MG in the bulk phase oil. Due to the improved interfacial performance, the inhibitory effect of the antioxidants was remarkably promoted in the presence of lecithin (L/GA/MG > L/GA > L/MG).

Deoxynivalenol-induced alterations in the redox status of HepG2 cells: identification of lipid hydroperoxides, the role of Nrf2-Keap1 signaling, and protective effects of zinc.

Deoxynivalenol (DON) is a type B trichothecenes that is widely contaminating human and animal foods, leading to several toxicological implications if ingested. Induction of oxidative stress and production of lipid peroxides were suggested to be the reasons for DON-induced cytotoxicity. However, detailed and comprehensive profiling of DON-related lipid hydroperoxides was not identified. Furthermore, the mechanisms behind DON-induced cytotoxicity and oxidative stress have received less attention. Zinc (Zn) is an essential element that has antioxidant activities; however, the protective effects of Zn against DON-induced adverse effects were not examined. Therefore, this study was undertaken to investigate DON-induced cytotoxicity and oxidative damage to human HepG2 cell lines. Furthermore, a quantitative estimation for the formed lipid hydroperoxides was conducted using LC-MS/MS. In addition, DON-induced transcriptomic changes on the inflammatory markers and antioxidant enzymes were quantitatively examined using qPCR. The protective effects of Zn against DON-induced cytotoxicity and oxidative stress, the formation of lipid hydroperoxides (LPOOH), and antioxidant status in HepG2 cells were investigated. Finally, the effects of DON and Zn on the Nrf2-Keap1 pathway were further explored. The achieved results indicated that DON caused significant cytotoxicity in HepG2 cells accompanied by significant oxidative damage and induction of the inflammatory markers. Identification of DON-related LPOOH revealed the formation of 22 LPOOH species including 14 phosphatidylcholine hydroperoxides, 5 triacylglycerol hydroperoxides, and 3 cholesteryl ester hydroperoxides. DON caused significant downregulation of Nrf2-regulated antioxidant enzymes. Zn administration led to significant protection of HepG2 cells against DON-induced adverse effects, probably via activation of the Nrf2-Keap1 pathway.

Modification of proteins by reactive lipid oxidation products and biochemical effects of lipoxidation.

Lipid oxidation results in the formation of many reactive products, such as small aldehydes, substituted alkenals, and cyclopentenone prostaglandins, which are all able to form covalent adducts with nucleophilic residues of proteins. This process is called lipoxidation, and the resulting adducts are called advanced lipoxidation end products (ALEs), by analogy with the formation of advanced glycoxidation end products from oxidized sugars. Modification of proteins by reactive oxidized lipids leads to structural changes such as increased ß-sheet conformation, which tends to result in amyloid-like structures and oligomerization, or unfolding and aggregation. Reaction with catalytic cysteines is often responsible for the loss of enzymatic activity in lipoxidized proteins, although inhibition may also occur through conformational changes at more distant sites affecting substrate binding or regulation. On the other hand, a few proteins are activated by lipoxidation-induced oligomerization or interactions, leading to increased downstream signalling. At the cellular level, it is clear that some proteins are much more susceptible to lipoxidation than others. ALEs affect cell metabolism, protein-protein interactions, protein turnover via the proteasome, and cell viability. Evidence is building that they play roles in both physiological and pathological situations, and inhibiting ALE formation can have beneficial effects.

Tumor Antigen Mediated Conformational Changes of Nanoplatform for Activated Photodynamic Therapy.

Photodynamic therapy (PDT) is a noninvasive powerful tool for tumor treatment. However, phototoxicity seriously limits the clinical application of PDT, and activated PDT specifically response to tumor cell antigen is rarely reported. Herein, a tumor cell specific "switch-on" PDT nanoplatform, which employs a well-designed hairpin structure mucl protein (MUC1) aptamer (Apt) as specific linker to conjugate gold nanorod and Chlorin e6 (Ce6) (GNR/Apt-Ce6) is prepared, and "switch on" via conformational changes of aptamer-induced fluorescence resonance energy transfer missing between GNR and Ce6 for selective tumor therapy. In the absence of tumor cells, MUC1 Apt keeps a hairpin structure, leading to Ce6 closely adhered to the surface of GNR, PDT is in an "off" state even under the irradiations. On the contrary, in the presence of tumor cells with overexpressed MUC1, Apt specifically recognizes and binds to MUC1, resulting in conformational changes of Apt from regular hairpin to extended chain structure. Thus with an enlarged distance between Ce6 and GNR, PDT is switched-on. GNR/Apt-Ce6 shows excellent PDT efficacy in tumor-bearing mice (55.1% vs 1.3%, tumor apoptosis rate of GNR/Apt-Ce6 vs GNR/random sequence-Ce6) due to its high tumor-targeting and "switch-on" properties. The strategy of tumor antigen activated PDT is expected to provide a new perspective for clinical application.

Quantitation of Lipid Peroxidation Product DNA Adducts in Human Prostate by Tandem Mass Spectrometry: A Method That Mitigates Artifacts.

Reactive oxygen species (ROS) and chronic inflammation contribute to DNA damage of many organs, including the prostate. ROS cause oxidative damage to biomolecules, such as lipids, proteins, and nucleic acids, resulting in the formation of toxic and mutagenic intermediates. Lipid peroxidation (LPO) products covalently adduct to DNA and can lead to mutations. The levels of LPO DNA adducts reported in humans range widely. However, a large proportion of the DNA adducts may be attributed to artifact formation during the steps of isolation and nuclease digestion of DNA. We established a method that mitigates artifacts for most LPO adducts during the processing of DNA. We have applied this methodology to measure LPO DNA adducts in the genome of prostate cancer patients, employing ultrahigh-performance liquid chromatography electrospray ionization ion trap multistage mass spectrometry. Our preliminary data show that DNA adducts of acrolein, 6-hydroxy-1,N2-propano-2'-deoxyguanosine (6-OH-PdG) and 8-hydroxy-1,N2-propano-2'-deoxyguanosine (8-OH-PdG) (4-20 adducts per 107 nucleotides) are more prominent than etheno (ε) adducts (<0.5 adducts per 108 nucleotides). This analytical methodology will be used to examine the correlation between oxidative stress, inflammation, and LPO adduct levels in patients with benign prostatic hyperplasia and prostate cancer.

Boosting the Ferroptotic Antitumor Efficacy via Site-Specific Amplification of Tailored Lipid Peroxidation.

Ferroptosis is an iron-dependent cell death pathway that can eradicate certain apoptosis-insensitive cancer cells. The ferroptosis-inducing molecules are tailored lipid peroxides whose efficacy is compromised in hypoxic solid tumor and lack of tumor selectivity. It has been demonstrated that ascorbate (Asc) in pharmacological concentrations can selectively kill cancer cells via accumulating hydrogen peroxide (H2O2) only in tumor extracellular fluids. It was hypothesized that Asc-induced, selective enrichment of H2O2 in tumor coupled with Fe3+ codelivery could simultaneously address the above two problems via boosting the levels of hydroxyl radicals and oxygen in the tumor site to ease peroxidation initiation and propagation, respectively. The aim of this work was to synergize the action of Asc with lipid-coated calcium phosphate (CaP) hybrid nanocarrier that can concurrently load polar Fe3+ and nonpolar RSL3, a ferroptosis inducer with the mechanism of inhibiting lipid peroxide repair enzyme (GPX4). The hybrid nanocarriers showed accelerated cargo release at acidic conditions (pH 5.0). The combinational approach (Asc plus nanocarrier) produced significantly elevated levels of hydroxyl radicals, lipid peroxides, and depleted glutathione under hypoxia, which was accompanied with the strong cytotoxicity (IC50 = 1.2 ± 0.2 µM) in the model 4 T1 cells. In the 4 T1 tumor-bearing xenograft mouse model, the intravenous nanocarrier delivery plus intraperitoneal Asc administration resulted in a superior antitumor performance in terms of tumor suppression, which did not produce supplementary adverse effects to the healthy organs. This work provides a novel approach to enhance the potency of ferroptotic nanomedicine against solid tumors without inducing additional side effects.

Self-Assembled Responsive Bilayered Vesicles with Adjustable Oxidative Stress for Enhanced Cancer Imaging and Therapy.

In the present study, we report the development of magnetic-plasmonic bilayer vesicles assembled from iron oxide-gold Janus nanoparticles (Fe3O4-Au JNPs) for reactive oxygen species (ROS) enhanced chemotherapy. The amphiphilic Fe3O4-Au JNPs were grafted with poly(ethylene glycol) (PEG) on the Au surface and ROS-generating poly(lipid hydroperoxide) (PLHP) on the Fe3O4 surface, respectively, which were then assembled into vesicles containing two closely attached Fe3O4-Au NPs layers in opposite directions. The self-assembly mechanism of the bilayered vesicles was elucidated by performing a series of numerical simulations. The enhanced optical properties of the bilayered vesicles were verified by the calculated results and experimental data. The vesicles exhibited enhanced T2 relaxivity and photoacoustic properties over single JNPs due to the interparticle magnetic dipole interaction and plasmonic coupling. In particular, the vesicles are pH responsive and disassemble into single JNPs in the acidic tumor environment, activating an intracellular biochemical reaction between the grafted PLHP and released ferrous ions (Fe2+) from Fe3O4 NPs, resulting in highly efficient local ROS generation and increased intracellular oxidative stress. In combination with the release of doxorubicin (DOX), the vesicles combine ROS-mediated cytotoxicity and DOX-induced chemotherapy, leading to greatly improved therapeutic efficacy than monotherapies. High tumor accumulation efficiency and fast vesicle clearance from the body were also confirmed by positron emission tomography (PET) imaging of radioisotope 64Cu-labeled vesicles.

New Insights into the Impact of Sodium Chloride on the Lipid Oxidation of Oil-in-Water Emulsions.

Salt, most often sodium chloride (NaCl), is commonly used in a variety of food emulsions. However, little is known about the detailed mechanism of how NaCl influences the lipid oxidation and thus the shelf life of those products. In this study, we report a new mechanism through which NaCl could help inhibit the lipid oxidation of sodium dodecyl sulfate (SDS)-stabilized oil-in-water (O/W) emulsions. Results showed that NaCl significantly lowered the critical micelle concentration (CMC) of SDS, which further led to greater amounts of lipid hydroperoxides being solubilized by SDS micelles into the aqueous phase of emulsion. NaCl also altered the distribution of δ-tocopherol between the aqueous and oil phase of emulsion. Such changes of the physical locations of lipid hydroperoxides and δ-tocopherol were responsible for the improved oxidative stability of NaCl-added O/W emulsions in the absence or presence of δ-tocopherol.

Lipidomic methodologies for biomarkers of chronic inflammation in nutritional research: ω-3 and ω-6 lipid mediators.

The evolutionary history of hominins has been characterized by significant dietary changes, which include the introduction of meat eating, cooking, and the changes associated with plant and animal domestication. The Western pattern diet has been linked with the onset of chronic inflammation, and serious health problems including obesity, metabolic syndrome, and cardiovascular diseases. Diets enriched with ω-3 marine PUFAs have revealed additional improvements in health status associated to a reduction of proinflammatory ω-3 and ω-6 lipid mediators. Lipid mediators are produced from enzymatic and non-enzymatic oxidation of PUFAs. Interest in better understanding the occurrence of these metabolites has increased exponentially as a result of the growing evidence of their role on inflammatory processes, control of the immune system, cell signaling, onset of metabolic diseases, or even cancer. The scope of this review has been to highlight the recent findings on: a) the formation of lipid mediators and their role in different inflammatory and metabolic conditions, b) the direct use of lipid mediators as antiinflammatory drugs or the potential of new drugs as a new therapeutic option for the synthesis of antiinflammatory or resolving lipid mediators and c) the impact of nutritional interventions to modulate lipid mediators synthesis towards antiinflammatory conditions. In a second part, we have summarized methodological approaches (Lipidomics) for the accurate analysis of lipid mediators. Although several techniques have been used, most authors preferred the combination of SPE with LC-MS. Advantages and disadvantages of each method are herein addressed, as well as the main LC-MS difficulties and challenges for the establishment of new biomarkers and standardization of experimental designs, and finally to deepen the study of mechanisms involved on the inflammatory response.

Synchronous Chemoradiation Nanovesicles by X-Ray Triggered Cascade of Drug Release.

The approach of concurrent-to-synchronous chemoradiation has now been advanced by well-designed nanovesicles that permit X-ray irradiation-triggered instant drug release. The nanovesicles consist of Au nanoparticles tethered with irradiation labile linoleic acid hydroperoxide (LAHP) molecules and oxidation-responsive poly(propylene sulfide)-poly(ethylene glycol) (PPS-PEG) polymers, where DOX were loaded in the inner core of the vesicles (Au-LAHP-vDOX). Upon irradiation, the in situ formation of hydroxyl radicals from LAHP molecules triggers the internal oxidation of PPS from being hydrophobic to hydrophilic, leading to degradation of the vesicles and burst release of cargo drugs. In this manner, synchronous chemoradiation showed impressive anticancer efficacy both in vitro and in a subcutaneous mouse tumor model by one-dose injection and one-time irradiation.

Distress and eustress of reactive electrophiles and relevance to light stress acclimation via stimulation of thiol/disulphide-based redox defences.

Photosynthetic organisms suffering from light stress have to cope with an increased formation of reactive short-chain aldehydes. Singlet oxygen generated from highly-charged reaction centres can peroxidise the poly-unsaturated fatty acid (PUFA)-rich thylakoid membranes they are embedded in. Lipid peroxides decay to release α,ß-unsaturated aldehydes that are reactive electrophile species (RES). Acrolein is one of the most abundant and reactive RES produced in chloroplasts. Here, in the model chlorophyte alga Chlamydomonas reinhardtii, a clear concentration-dependent "distress" induced by acrolein intoxication was observed in conjunction with depletion of the glutathione pool. The glutathione redox state (EGSSG/2GSH) strongly correlated (R2 = 0.95) with decreasing Fv/Fm values of chlorophyll fluorescence. However, treatment of C. reinhardtii with sub-toxic acrolein concentrations increased glutathione concentrations and raised the protein levels of a glutathione-S-transferase (GSTS1), mimicking the response to excess light, indicating that at lower concentrations, acrolein may contribute to high light acclimation, which could be interpreted as "eustress". Furthermore, similar patterns of chloroplastic protein carbonylation occurred under light stress and in response to exogenous acrolein. Priming cells by low doses of acrolein increased the alga's resistance to singlet oxygen. A RNA seq. analysis showed a large overlap in gene regulation under singlet oxygen and acrolein stresses. Particularly enriched were transcripts of enzymes involved in thiol/disulphide exchanges. Some of the genes are regulated by the SOR1 transcription factor, but acrolein treatment still induced an increase in glutathione contents and enhanced singlet oxygen tolerance of the sor1 mutant. The results support a role for RES in chloroplast-to-nucleus retrograde signalling during high light acclimation, with involvement of SOR1 and other pathways.

The prooxidant activity of salts on the lipid oxidation of lecithin-stabilized oil-in-water emulsions.

Salts reduction/substitution have gained a lot interest from food industry since the US Food and Drug Administration (FDA) has issued a draft guidance for salt reduction. However how changes of salts in food formulation could influence lipid oxidation is still not fully understood. Using oil-in-water emulsions stabilized by a natural emulsifier - lecithin at pH 7.0 as a model system, this study evaluated how salts affect the physical parameters of the emulsion, the chelating activity of lecithin and thus the lipid oxidation of these emulsions. Results showed that salts increased the particle size, the negative charge of the oil droplets, and the amount of iron chelated by lecithin. Lipid oxidation lag phases were shortened by addition of salts, by 1 day and 2 days for lipid hydroperoxides and thiobarbituric acid reactive substances measurements respectively. These results provide some new insights on the mechanisms of how salts could affect the lipid oxidation of food emulsions.

Use of aqueous extract of noni in extender for sheep semen freezing / Utilização do extrato aquoso de noni em diluente para congelação de sêmen ovino

The study aimed to evaluate the action of aqueous extract of noni in an extender for sheep semen freezing. Treatments differed in inclusion of aqueous extract of noni in the extender: T1 ˗ no addition; T2 ˗ 24µg/mL; T3 ˗ 72µg/mL; and T4 ˗ 120µg/mL. Ejaculates were collected, diluted in the four treatments, and frozen. After thawing, the semen was subjected to a thermoresistance test and evaluated for subjective motility, vigor, membrane integrity assessment by hypo-osmotic swelling test, live-dead assay, computer-assisted sperm analysis and the status of sperm capacitation and acrosome reaction. Data were subjected to ANOVA, and then to Student Newman Keuls's test at 5% significance level. In the thermoresistance test after two hours of incubation, motility in T4 (120µg/mL) was lower than in the other treatments, with no differences in the HoS test in either diluted semen or in the semen evaluated immediately post-thawing, while for the other times, treatments showed similar responses. Regarding the motility parameters, a difference was observed for progressive motility, curvilinear velocity, average path velocity, and amplitude of lateral head displacement. As to the sperm capacitation status, a difference was observed between treatments for the sperm capacitated with intact acrosome.(AU)

Este estudo teve como objetivo avaliar a ação do extrato aquoso de noni em diluente para congelação de sêmen de carneiro. Os tratamentos diferiram quanto à inclusão de extrato aquoso de noni ao meio diluidor em: T1˗ sem adição de extrato; T2˗ 24µg/mL ; T3- 72µg/mL e 120µg/mL. Por meio de vagina artificial, 16 ejaculados foram coletados, diluídos entre os quatro tratamentos e congelados. Após o descongelamento, o sêmen foi submetido ao teste de termorresistência e avaliado quanto à motilidade subjetiva, ao vigor espermático, à integridade de membrana pelo teste hiposmótico, bem como ao teste supravital, à análise de sêmen assistida por computador (CASA) e ao status de capacitação espermática e de reação acrossomal. Os dados foram submetidos a uma análise de variância, seguida pelo teste de Student-Newman-Keuls com 5% de significância. No teste de termorresistência, após duas horas de incubação, a motilidade do T4 (120µg/mL) apresentou-se inferior aos demais tratamentos. Não houve diferença significativa no teste HOS tanto para o sêmen diluído quanto para o sêmen avaliado imediatamente pós-descongelação; para as demais horas, os tratamentos apresentaram comportamento semelhante. Para os parâmetros de cinética, foi observada diferença estatística para motilidade progressiva, velocidade curvilinear, velocidade do percurso médio e amplitude de deslocamento lateral da cabeça. Quanto ao estado de capacitação espermática, observou-se diferença entre os tratamentos para espermatozoide capacitado com acrossomo intacto.(AU)

Activatable Singlet Oxygen Generation from Lipid Hydroperoxide Nanoparticles for Cancer Therapy.

Reactive oxygen species (ROS)-induced apoptosis is a widely practiced strategy for cancer therapy. Although photodynamic therapy (PDT) takes advantage of the spatial-temporal control of ROS generation, the meticulous participation of light, photosensitizer, and oxygen greatly hinders the broad application of PDT as a first-line cancer treatment option. An activatable system has been developed that enables tumor-specific singlet oxygen (1 O2 ) generation for cancer therapy, based on a Fenton-like reaction between linoleic acid hydroperoxide (LAHP) tethered on iron oxide nanoparticles (IO NPs) and the released iron(II) ions from IO NPs under acidic-pH condition. The IO-LAHP NPs are able to induce efficient apoptotic cancer cell death both in vitro and in vivo through tumor-specific 1 O2 generation and subsequent ROS mediated mechanism. This study demonstrates the effectiveness of modulating biochemical reactions as a ROS source to exert cancer death.

Proton pump inhibitor induced collagen expression in colonocytes is associated with collagenous colitis.

AIM: To elucidate the role of proton pump inhibitors (PPIs) in collagenous disease, direct effect of PPI on colonocytes was examined. METHODS: Collagenous colitis is a common cause of non-bloody, watery diarrhea. Recently, there has been increasing focus on the use of proton PPIs as a risk factor for developing collagenous colitis. Mouse CT26 colonic cells were treated with PPI and/or PPI-induced alkaline media. Expression of fibrosis-associated genes was examined by RT-PCR. In human materials, collagen expression was examined by immunohistochemistry. RESULTS: CT26 cells expressed a Na+-H+ exchanger gene (solute carrier family 9, member A2). Treatment with PPI and/or PPI-induced alkaline media caused growth inhibition and oxidative stress in CT26 cells. The treatment increased expression of fibrosis inducing factors, transforming growth factor ß and fibroblast growth factor 2. The treatment also decreased expression of a negative regulator of collagen production, replication factor C1, resulting in increased expression of collagen types III and IV in association with lipid peroxide. In biopsy specimens from patients with collagenous colitis, type III and IV collagen were increased. Increase of type III collagen was more pronounced in PPI-associated collagenous colitis than in non-PPI-associated disease. CONCLUSION: From these findings, the reaction of colonocytes to PPI might participate in pathogenesis of collagenous colitis.

Oxidative Stability in Oil-in-Water Emulsions with Quercetin or Rutin Under Iron Catalysis or Riboflavin Photosensitization.

The effects of quercetin and rutin on the oxidative stability of oil-in-water (O/W) emulsions were tested under riboflavin (RF) photosensitization in the presence or absence of FeCl2 . The degree of oxidation in O/W emulsions was determined by headspace oxygen content, conjugated dienes, and lipid hydroperoxides. Quercetin chelated more metal than did rutin in iron catalyzed O/W emulsions. Generally, 0.1 mM quercetin and rutin was oxidative while 0.5 and 1.0 mM quercetin and rutin was antioxidative in O/W emulsions under RF photosensitization. Depending on the analysis method, the antioxidants had different strengths. The antioxidative or oxidative properties of quercetin and rutin vary in O/W emulsions and depend the quercetin and rutin concentrations and oxidative forces like transition metals, RF photosensitization, or a combination thereof.

Pigment Epithelium Derived Factor Peptide Protects Murine Hepatocytes from Carbon Tetrachloride-Induced Injury.

Fibrogenesis is induced by repeated injury to the liver and reactive regeneration and leads eventually to liver cirrhosis. Pigment epithelium derived factor (PEDF) has been shown to prevent liver fibrosis induced by carbon tetrachloride (CCl4). A 44 amino acid domain of PEDF (44-mer) was found to have a protective effect against various insults to several cell types. In this study, we investigated the capability of synthetic 44-mer to protect against liver injury in mice and in primary cultured hepatocytes. Acute liver injury, induced by CCl4, was evident from histological changes, such as cell necrosis, inflammation and apoptosis, and a concomitant reduction of glutathione (GSH) and GSH redox enzyme activities in the liver. Intraperitoneal injection of the 44-mer into CCl4-treated mice abolished the induction of AST and ALT and markedly reduced histological signs of liver injury. The 44-mer treatment can reduce hepatic oxidative stress as evident from lower levels of lipid hydroperoxide, and higher levels of GSH. CCl4 caused a reduction of Bcl-xL, PEDF and PPARγ, which was markedly restored by the 44-mer treatment. Consequently, the 44-mer suppressed liver fibrosis induced by repeated CCl4 injury. Furthermore, our observations in primary culture of rat hepatocytes showed that PEDF and the 44-mer protected primary rat hepatocytes against apoptosis induced by serum deprivation and TGF-ß1. PEDF/44-mer induced cell protective STAT3 phosphorylation. Pharmacological STAT3 inhibition prevented the antiapoptotic action of PEDF/44-mer. Among several PEDF receptor candidates that may be responsible for hepatocyte protection, we demonstrated that PNPLA2 was essential for PEDF/44-mer-mediated STAT3 phosphorylation and antiapoptotic activity by using siRNA to selectively knockdown PNPLA2. In conclusion, the PEDF 44-mer protects hepatocytes from single and repeated CCl4 injury. This protective effect may stem from strengthening the counter oxidative stress capacity and induction of hepatoprotective factors.

Generation of cytotoxic molecules and oxidative stress in haemolymph of pebrinised tasar silkworm Antheraea mylitta Drury.

The present study was carried out to investigate the effects of microsporidial infection on redox regulation mechanism and oxidative stress in tasar silkworm Antheraea mylitta. High level of superoxide radical (p < 0.05), nitric oxide (p < 0.001) and lipid peroxidation (p < 0.001) was observed in haemolymph of pebrinised larvae, which indicated the resultant generation of cytotoxic molecules and oxidative damage. Increased phenol oxidase (PO) activity in haemolymph of pebrinised larvae indicated the activation of immune defences during pathological conditions. In addition, higher level of glutathione-S-tranferase (GST) activity and reduced glutathione (GSH) level observed in pebrinised larvae indicated adaptive behaviour of tissue against toxic oxyradicals (p < 0.05). Conversely, low level of ascorbic acid (ASA) content suggested that the larvae might have used these compounds to counteract stress in tissues or low uptake under microspridial infection (p < 0.05). Present findings provide new insights into the cellular and biochemical bases of host-pathogen interactions in tasar silkworm A. mylitta.

Prediction of oxidation parameters of purified Kilka fish oil including gallic acid and methyl gallate by adaptive neuro-fuzzy inference system (ANFIS) and artificial neural network.

BACKGROUND: As a result of concerns regarding possible health hazards of synthetic antioxidants, gallic acid and methyl gallate may be introduced as natural antioxidants to improve oxidative stability of marine oil. Since conventional modelling could not predict the oxidative parameters precisely, artificial neural network (ANN) and neuro-fuzzy inference system (ANFIS) modelling with three inputs, including type of antioxidant (gallic acid and methyl gallate), temperature (35, 45 and 55 °C) and concentration (0, 200, 400, 800 and 1600 mg L(-1) ) and four outputs containing induction period (IP), slope of initial stage of oxidation curve (k1 ) and slope of propagation stage of oxidation curve (k2 ) and peroxide value at the IP (PVIP ) were performed to predict the oxidation parameters of Kilka oil triacylglycerols and were compared to multiple linear regression (MLR). RESULTS: The results showed ANFIS was the best model with high coefficient of determination (R(2) = 0.99, 0.99, 0.92 and 0.77 for IP, k1 , k2 and PVIP , respectively). So, the RMSE and MAE values for IP were 7.49 and 4.92 in ANFIS model. However, they were to be 15.95 and 10.88 and 34.14 and 3.60 for the best MLP structure and MLR, respectively. So, MLR showed the minimum accuracy among the constructed models. CONCLUSION: Sensitivity analysis based on the ANFIS model suggested a high sensitivity of oxidation parameters, particularly the induction period on concentrations of gallic acid and methyl gallate due to their high antioxidant activity to retard oil oxidation and enhanced Kilka oil shelf life. © 2016 Society of Chemical Industry.