Derivatization strategy for semi-quantitative analysis of medium- and long-chain fatty acids using multiple reaction monitoring

Low level exposure to BDE-47 facilitates the development of prostate cancer through TOP2A/LDHA/lactylation positive feedback circuit

2,2',4,4'-tetra brominated diphenyl ether (BDE-47) is one of the most widely distributed congeners of polybrominated diphenyl ethers. While the relationships between BDE-47 exposure and other hormone-dependent cancers (such as breast cancer) are well established, no previous study has examined whether BDE-47 exposure is related to the development of prostate cancer (PCa). Through bulk and single-cell RNA sequencing (scRNA-seq) analyses, as well as in vitro and in vivo experiments, this study aims to investigate the effect of BDE-47 exposure on PCa progression. Herein, we found that low dose BDE-47 promoted the growth of PCa cells (PC3 and LNCaP) in a dose-dependent manner in vitro and in vivo. Based on Comparative Toxicogenomics Database (CTD) and The Cancer Genome Atlas (TCGA), we obtained 34 BDE-47-related and PCa-related genes through screening and overlapping. These genes were significantly enriched in fatty acid metabolism-related gene ontology (GO) terms, which were also enriched for genes targeting BDE-47 obtained from the UniProt. Through scRNA-seq data, certain cell type-specific expression was observed for CYP2E1, PIK3R1, FGF2, and TOP2A in PCa tissues from men. Molecular docking simulation showed that BDE-47 was tightly bound to the protein residues of AOX1, PIK3R1, FGF2, CAV2, CYP2E1 and TOP2A. Further screening in terms of patient overall survival, receiver operating characteristics curve (ROC) curve and Gleason score grading system narrowed the candidate genes down to TOP2A. Mechanistically, the growth-promoting effect of BDE-47 on PCa cells could be reversed by TOP2A inhibitor. RNA-seq followed by experimental verification demonstrated that TOP2A promoted PCa progression through upregulating LDHA and glycolysis. Furthermore, lactate upregulated TOP2A transcription through lactylation of H3K18la in PCa cells, which could be rescued by LDHA knockdown. Taken together, low dose BDE-47 triggered PCa progression through TOP2A/LDHA/lactylation positive feedback circuit, thus revealing epigenetic shifting and metabolic reprogramming underpinning BDE-47-induced carcinogenesis of the prostate.

Sample preparation for fatty acid analysis in biological samples with mass spectrometry-based strategies

Fatty acids (FAs) have attracted many interests for their pivotal roles in many biological processes. Imbalance of FAs is related to a variety of diseases, which makes the measurement of them important in biological samples. Over the past two decades, mass spectrometry (MS) has become an indispensable technique for the analysis of FAs owing to its high sensitivity and precision. Due to complex matrix effect of biological samples and inherent poor ionization efficiency of FAs in MS, sample preparation including extraction and chemical derivatization prior to analysis are often employed. Here, we describe an updated overview of FA extraction techniques, as well as representative derivatization methods utilized in different MS platforms including gas chromatography-MS, liquid chromatography-MS, and mass spectrometry imaging based on different chain lengths of FAs. Derivatization strategies for the identification of double bond location in unsaturated FAs are also summarized and highlighted. The advantages, disadvantages, and prospects of these methods are compared and discussed. This review provides the development and valuable information for sample pretreatment approaches and qualitative and quantitative analysis of interested FAs using different MS-based platforms in complex biological matrices. Finally, the challenges of FA analysis are summarized and the future perspectives are prospected.

The chemical and biological characteristics of fatty acid esters of hydroxyl fatty acids

With the continuous advancements in detection methods and the exploration of unknown substances, an increasing number of bioactive compounds are being discovered. Fatty acid esters of hydroxyl fatty acids (FAHFAs), a class of endogenous lipids found in 2014, exhibit various physiological activities, such as improving glucose tolerance and insulin sensitivity, stimulating insulin secretion, and demonstrating broad anti-inflammatory effects. Moreover, some FAHFAs are closely linked to intestinal health and can serve as potential biomarkers for gut health. Various FAHFAs have been observed in food, including palmitic acid esters of hydroxy stearic acids (PAHSA), oleic acid esters of hydroxy stearic acids (OAHSA), linoleic acid esters of hydroxy linoleic acid (LAHLA). As a type of lipid regularly consumed in the daily diet, it is highly important to ascertain the types and quantities of FAHFAs present in the diet. This article, based on existing research, provides a review of the analysis methods for FAHFAs, particularly focusing on the separation of chiral isomers. It also summarizes the sources and contents of dietary FAHFAs, emphasizing their bioavailability and impact on the gut. Understanding the beneficial effects of these lipids in the diet can serve as a valuable reference for the development of specific functional foods.

Rapid and sensitive determination of free fatty acids based on in-source microdroplet-driven derivatization coupled with high-resolution mass spectrometry

Accurate and sensitive measurements of free fatty acids (FFAs) in biological samples are valuable for diagnosing and prognosing diseases. In this study, an in-source microdroplet derivation strategy combined with high-resolution mass spectrometry was developed to analyze FFAs in lipid extracts of biological samples directly. FFAs were rapidly derivated with 2-picolylamine (PA) in the microdroplet which is derived by electrospray. With the proposed method, twelve typical FFAs were determined reliably with high sensitivity and acceptable linearities (R2 ≥ 0.94). The LODs and LOQs for the twelve FFAs were 9-76 pg mL-1 and 30-253 pg mL-1, respectively. The developed method was applied to analyze the alteration of FFAs in liver and kidney samples of rats induced by perfluorooctane sulfonate (PFOS) exposure. The good results demonstrate that the established analysis technique is dependable and has promising applications in detecting FFAs associated with complex biological samples.

Effects of lotus seedpod oligomeric procyanidins on the inhibition of AGEs formation and sensory quality of tough biscuits

The advanced glycation end products (AGEs) are formed in baked products through the Maillard reaction (MR), which are thought to be a contributing factor to chronic diseases such as heart diseases and diabetes. Lotus seedpod oligomeric procyanidins (LSOPC) are natural antioxidants that have been added to tough biscuit to create functional foods that may lower the risk of chronic diseases. The effect of LSOPC on AGEs formation and the sensory quality of tough biscuit were examined in this study. With the addition of LSOPC, the AGEs scavenging rate and antioxidant capacity of LSOPC-added tough biscuits were dramatically improved. The chromatic aberration (ΔE) value of tough biscuits containing LSOPC increased significantly. Higher addition of LSOPC, on the other hand, could effectively substantially reduced the moisture content, water activity, and pH of LSOPC toughen biscuits. These findings imply that using LSOPC as additive not only lowers the generation of AGEs, but also improves sensory quality of tough biscuit.

Lipid metabolism dysfunction and toxicity of BDE-47 exposure in white adipose tissue revealed by the integration of lipidomics and metabolomics

2,2',4,4'-Tetrabromodiphenyl ether (BDE-47) is one of the main and toxic congeners of polybrominated diphenyl ether (PBDE) family and considered to be associated with the development of obesity. However, little is known about its direct metabolic alterations on white adipose tissue (WAT). In this study, we evaluated the impacts of BDE-47 exposure on WAT dysfunctions in mice fed with low-fat diet (LFD) or high-fat diet (HFD) by the integration analysis of mass spectrometry-based metabolomics and lipidomics. The results showed that BDE-47 exposure together with HFD intervention induced adipocyte hypertrophy and accelerated the weight gain of WAT, whereas no obvious effects were observed in mice fed with LFD. The combination of BDE-47 and HFD induced intolerable levels of metabolites in purine and glutathione metabolism pathways, sufficient to increase oxidative stress in WAT. Importantly, continuous exposure of BDE-47 in HFD -fed mice caused lipid metabolism dysfunction by promoting fatty acid uptake and de novo synthesis and suppressing β-oxidation, ultimately leading to the accumulation of saturated fatty acids, triglycerides in WAT. At the same time, BDE-47 increased inflammatory infiltration into WAT, consequently promoting the productions of cytokines, TNFα and IL-6, in HFD fed mice. It is found that dysfunction of lipid metabolism and increasing inflammation led to lipotoxicity in WAT and severe obesity in HFD mice. Taken together, our findings deepen the understanding of the obesogenic effect of BDE-47 and help identify new potential strategies for clarifying the molecular and metabolic mechanisms.

Profiling of Phenolic Compounds of Fruit Peels of Different Ecotype Bananas Derived from Domestic and Imported Cultivars with Different Maturity

Banana is one of the most produced and consumed fruits in the world and its fruit peel accounts for about 40% of the total fresh quantity of ripe fruit, which is usually regarded as waste and poses serious environmental hazards. However, it is a promising source of natural bioactive compounds including phenolic compounds. Determination of the phenolic compounds in fruit peel from different cultivars and subgroups over a range of maturities provides convincing information for making full use of them. This study developed a sensitive and reliable analytical method—ultra-high performance liquid chromatography—coupled with electrospray ionization tandem mass spectrometry (UPLC-MS/MS) for measuring phenolic compounds in fruit peel from different ecotype cultivars and subgroups with different maturity. The results showed that quinic acid had the highest concentration ratio among the main phenolic compounds in the green/ripe peel of all banana cultivars; among all banana cultivars, the total phenolic compound contents of green banana peel were significantly higher than that of ripe banana peel; the total phenolic compound contents in the green/ripe fruit peel of non-dessert bananas were significantly higher than that of dessert bananas (green: non-dessert banana 1.48 ± 0.44 mg/g vs. dessert banana 0.97 ± 0.12 mg/g; ripe: non-dessert banana 0.26 ± 0.13 mg/g vs. dessert banana 0.19 ± 0.06 mg/g). These data provide a basis for the rational utilization of phenolic compound extractions from banana peel with huge biomass in the next step.

Inhibition of Advanced Glycation End Products in Yogurt by Lotus Seedpod Oligomeric Procyanidin

The basic ingredients of yogurt include lactose and protein. Yogurt undergoes the Maillard reaction easily, producing many advanced glycation end products (AGEs) that cause some chronic diseases. Lotus seedpod oligomeric procyanidin (LSOPC) have demonstrated a strong inhibitory effect on AGE formation in simulated models; however, the inhibition of procyanidin on AGE formation and the subsequent effects on yogurt quality remains unknown. Our study demonstrated that LSOPC had a good inhibitory effect on the formation of fluorescent AGEs and Nε-carboxymethyl lysine (P < 0.05). The inhibitory capacity on AGEs and antioxidant activity of yogurt were positively correlated with the concentration of LSOPC. The effect of LSOPC on the physicochemical properties of yogurt was also evaluated. Bound water content, viscosity, and flavor of yogurt were significantly increased after LSOPC addition (P < 0.05). Therefore, LSOPC may lead to significant benefits for controlling AGE formation and improving the quality of yogurt.