Publications by authors named "Shunji Kato"

Liposome lipid peroxidation induced by cold atmospheric pressure plasma jet (CAPPJ) irradiation was investigated. The formation of thiobarbituric acid reactive substances (TBARS), an indicator of lipid peroxidation final products, as a function of irradiation was observed. Lipid radicals, peroxidation reaction intermediates generated by CAPPJ irradiation, were confirmed by increased NBD-pen fluorescence intensity.

View Article and Find Full Text PDF
Article Synopsis
  • The roasting process of sesame oil changes its internal composition, which affects its stability against oxidation, but this effect varies depending on the type of oxidation (thermal or photo).
  • The study compared different sesame oils (raw, refined, and roasted) and rapeseed oils by exposing them to thermal oxidation at 120℃ and photo-oxidation at 50,000 lx for 5 and 10 hours.
  • The findings indicate that roasted sesame oil is more stable during thermal oxidation due to antioxidant changes, while refined sesame oil is more stable under photo-oxidation, highlighting the significant impact of both roasting and refining processes on sesame oil’s oxidative stability.
View Article and Find Full Text PDF
Article Synopsis
  • * This study involved administering labeled forms of these acids and their hydroperoxides to mice and measuring the expired CO levels to determine catabolic rates, finding that the hydroperoxides were broken down more quickly than their corresponding fatty acids.
  • * The research suggests that during digestion, these hydroperoxides decompose into medium-chain compounds, which are then quickly absorbed by the liver and metabolized, supporting the idea that dietary lipid hydroperoxides do not enter the intestine intact but
View Article and Find Full Text PDF
Article Synopsis
  • Milk is highly nutritious, but lipid oxidation is a key factor in its spoilage, requiring effective prevention measures.
  • The study investigated oxidation mechanisms in long-life milk and analyzed specific lipid oxidation products using advanced techniques.
  • Findings indicate that long-life milk is more prone to photo-oxidation than thermal oxidation, emphasizing the role of radicals and suggesting strategies to prevent oxidation in milk and related products.
View Article and Find Full Text PDF

Ever since the proposal of ferroptosis, it has been studied as a nonapoptotic cell death caused by iron ion-dependent phospholipid (PL) peroxidation. We previously showed that treatment of human hepatoma cell line HepG2 with prepared PL hydroperoxide (PLOOH) resulted in ferroptosis. However, in human sebum, the major hydroperoxide is not PLOOH but squalene hydroperoxide (SQOOH), and to our knowledge, it is not established yet whether SQOOH induces ferroptosis in the skin.

View Article and Find Full Text PDF

As known for quite a long time now, even saturated fatty acids can be oxidized at high temperatures to produce unique aroma compounds, such as 2-alkanones and lactones. Hydroperoxide positional isomers with a hydroperoxy group at the 2-, 3-, 4-, or 5-position are hypothesized to be responsible for the formation of these aroma components, but this hypothesis has not been verified. For the first time, this study successfully prepared a series of glyceryl trioctanoate hydroperoxide (C8TG;OOH) isomers.

View Article and Find Full Text PDF

Glucosylceramide (GlcCer) belongs to sphingolipids and is found naturally in plant foods and other sources that humans consume daily. Our previous studies demonstrated that GlcCer prevents inflammatory bowel disease both in vitro and in vivo, whose patients are increasing alarmingly. Although some lipids are vulnerable to oxidation which changes their structure and activities, it is unknown whether oxidative modification of GlcCer affects its activity.

View Article and Find Full Text PDF

Background: Circulating phospholipid species have been shown to predict Alzheimer's disease (AD) prognosis but the link between phospholipid disturbances and subcortical small vessel cerebrovascular disease (CeVD) common in AD patients is not known.

Objective: Mass-spectrometry lipidomics was applied to quantify serum diacyl, alkenyl (ether), alkyl, and lyso phospholipid species in individuals with extensive CeVD (n = 29), AD with minimal CeVD (n = 16), and AD with extensive CeVD (n = 14), and compared them to age-matched controls (n = 27). Memory was assessed using the California Verbal Learning Test.

View Article and Find Full Text PDF
Article Synopsis
  • Docosahexaenoic acid (DHA) is sensitive to heat and light, making it prone to oxidation, which can affect its nutritional quality in food.
  • Researchers developed a new liquid chromatography-mass spectrometry (LC-MS/MS) method to analyze esterified DHA mono-hydroperoxide isomers directly, building on previous work with free DHA;OOH isomers.
  • The study found that even refrigerated mackerel showed signs of radical oxidation of esterified DHA, highlighting the need to better understand and prevent DHA oxidation in food products.
View Article and Find Full Text PDF

Food lipid oxidation provides various volatile compounds involved in food flavor via the decomposition of lipid hydroperoxide (LOOH). This study predicted the pathways which can coherently explain LOOH decomposition focusing on hydroperoxy octadecadienoic acid (HpODE) isomers (9-EZ-HpODE, 9-EE-HpODE, 10-HpODE, 12-HpODE, 13-ZE-HpODE, and 13-EE-HpODE) which are the major LOOH contained in edible oils. Each standard was first prepared and thermally decomposed.

View Article and Find Full Text PDF

Following a growing interest in the physiological effects of pyrroloquinoline quinone (PQQ), more cell culture experiments have begun to elucidate its mechanism of action. However, to our knowledge, no reports have used instrumental analysis, such as liquid chromatography-tandem mass spectrometry (LC-MS/MS), to study cellular uptake of PQQ. In addition, despite the propensity of PQQ to react with amino acids and other compounds, only a handful of cell culture experiments have been conducted on PQQ derivatives.

View Article and Find Full Text PDF

Ferroptosis is mainly caused by iron-mediated peroxidation of phospholipids and has recently attracted attention due to its involvement in various diseases. At the center of it is supposedly the inability of glutathione peroxidase 4 (GPX4) to reduce excess peroxidized phospholipids (e.g.

View Article and Find Full Text PDF

The in vivo presence of triacylglycerol hydroperoxide (TGOOH), a primary oxidation product of triacylglycerol (TG), has been speculated to be involved in various diseases. Thus, considerable attention has been paid to whether dietary TGOOH is absorbed from the intestine. In this study, we performed the lymph duct-cannulation study in rats and analyzed the level of TGOOH in lymph following administration of a TG emulsion containing TGOOH.

View Article and Find Full Text PDF
Article Synopsis
  • The study focuses on understanding the oxidation mechanisms of extra virgin olive oil (EVOO), specifically through radical and singlet oxygen oxidation.
  • Researchers used LC-MS/MS to quantitatively analyze triacylglycerol hydroperoxide (TGOOH) isomers in EVOO, including key standards for specific hydroperoxy triacylglycerols.
  • The findings align with existing knowledge about the oxidation of oils and highlight how factors like olive species and extraction methods affect EVOO's quality and stability.
View Article and Find Full Text PDF
Article Synopsis
  • Acid value (AV) measures oil degradation by looking at free fatty acids from the breakdown of triacylglycerols, but this study hypothesizes that carboxylic acids from triacylglycerol oxidation also contribute to AV.
  • Heating canola oil at 180 °C for 6 hours raised the AV significantly, but the increase from free fatty acids was minimal, suggesting other factors are at play.
  • The research identified specific azelaoyl-triacylglycerols contributing to AV increase, indicating that AV is also a marker for the thermal oxidation of oils.
View Article and Find Full Text PDF
Article Synopsis
  • 2-Propenal (acrolein) is a toxic compound produced when edible oils break down, and previous studies attributed its formation primarily to radical oxidation of fatty acids.
  • This study examines an alternative pathway for acrolein generation through singlet oxygen oxidation, revealing that certain fatty acid hydroperoxide isomers are key contributors to acrolein production.
  • The findings indicate that oils rich in linoleic acid become more acrolein-rich when exposed to light, suggesting that oil storage and processing conditions can be optimized to minimize acrolein exposure.
View Article and Find Full Text PDF

Background: Transient receptor potential vanilloid 2 (TRPV2) is a highly Ca-permeable ion channel that is involved in a number of cellular processes. It is expressed in various human cancers; however, the role of TRPV2 in gastric cancer (GC) remains poorly understood.

Methods: TRPV2 gene expression was knocked down in GC cell lines by small-interfering RNA (siRNA), and the biological roles of TRPV2 in the proliferation, migration, and invasion of GC cells were then investigated.

View Article and Find Full Text PDF

Skin surface lipids (SSLs) form the first barrier that protects the human organism from external stressors, disruption of the homeostasis of SSLs can result in severe skin abnormalities. One of the main causes of this disruption is oxidative stress that is primarily due to SSLs oxidation. Squalene (SQ), the most abundant lipid among SSLs, was shown to first undergo singlet molecular oxygen (O) oxidation to yield 6 SQ-monohydroperoxide (SQ-OOH) isomers as the primary oxidation products.

View Article and Find Full Text PDF

Alcoholic fatty liver disease (AFLD) is characterized by lipid accumulation and inflammation and can progress to cirrhosis and cancer in the liver. AFLD diagnosis currently relies on histological analysis of liver biopsies. Early detection permits interventions that would prevent progression to cirrhosis or later stages of the disease.

View Article and Find Full Text PDF

The continuous formation and accumulation of oxidized lipids (e.g., lipid hydroperoxides (LOOH)) which are present even in plasma lipoproteins of healthy subjects, are ultimately considered to be linked to various diseases.

View Article and Find Full Text PDF