Effects of fluorescent carbon dots from the baked lamb on energy and lipid metabolism

Synthesis of carbon dots from spent coffee grounds: transforming waste into potential biomedical tools

Carbon dots (CDs) are small-sized, spherical nanoparticles presenting amorphous carbon cores with nanocrystalline regions of a graphitic structure. They show unique properties such as high aqueous solubility, robust chemical inertness, and non-toxicity and can be manufactured at a relatively low cost. They are also well known for outstanding fluorescence tunability and resistance to photobleaching. Together, these properties boost their potential to act as drug delivery systems (DDSs). This work presents a low-cost synthesis of CDs by upcycling spent coffee grounds (SCGs) and transforming them into value-added products. This synthetic route eliminates the use of highly toxic heavy metals, high energy-consuming reactions and long reaction times, which can improve biocompatibility while benefiting the environment. A series of physico-chemical characterisation techniques demonstrated that these SCG-derived CDs are small-sized nanoparticles with tunable fluorescence. In vitro studies with 120 h of incubation of SCG-derived CDs demonstrated their specific antiproliferative effect on the breast cancer CAL-51 cell line, accompanied by increased reactive oxygen species (ROS) production. Importantly, no impact was observed on healthy breast, kidney, and liver cells. Confocal laser scanning microscopy confirmed the intracellular accumulation of SCG-derived CDs. Furthermore, the drug efflux pumps P-glycoprotein (P-gp) and the breast cancer resistance protein (BCRP) did not impact CD accumulation in the cancer cells.

Toxicological mechanisms of carbon polymers in accelerating cognitive decline in Alzheimer's disease

INTRODUCTION

Alzheimer's disease (AD) is the primary cause of dementia and is emerging as a global threat to human health. Increased availability of processed food is identified as a crucial environmental risk factor underlying the prevalence of Alzheimer's disease. Carbon polymers (CPs), as neo-formed substances and ubiquitous in thermally processed foods, the relationship between them and AD onset is remains unclear.

OBJECTIVES

The effect of CPs on AD onset was examined and the toxicological mechanisms of prolonged exposure to CPs derived from thermal processed foods on AD progression were comprehensively investigated using a scopolamine-induced neuroinflammatory cell models and the transgenic APPswe/PSEN1dE9 (APP/PS1) AD mouse.

METHODS

The CPs were extracted from thermally processed foods and the effects of CPs exposure on oxidative stress in neuroinflammatory cells were evaluated using scopolamine-induced PC12 cells as a neuroinflammation model. Furthermore, APP/PS1 AD mice were used to validate the potential adverse impacts of prolonged exposure to CPs on AD progression through the Morris water maze and open field test. In addition, histopathological examination, including immunofluorescence, immunohistochemistry, Nissl staining, and H&E, of the brain tissue in AD mice after chronic CPs treatment was performed to elucidate the underlying risk of dietary exposure to CPs on AD progression.

RESULTS

Exposure to CPs enhanced oxidative damage in neuroinflammatory cells, as demonstrated by impaired mitochondrial function and activated NF-κB/MAPK signaling pathways. Further results from electron spin resonance substantiated the catalytic properties of CPs, which accelerated oxidative damage through promoting free radical generation. Using transgenic AD mice model, our findings also demonstrated that prolonged CPs exposure aggravated AD-associated pathology, as evidenced by increased amyloid-beta deposition and glial cell activation, ultimately accelerating cognitive decline.

CONCLUSION

These findings provide compelling evidence of the potential health risks associated with long-term dietary exposure to CPs and provide insight into the relationship between foodborne risk factors and neurodegenerative diseases.

Engineering of Green Carbon Dots for Biomedical and Biotechnological Applications

Carbon dots (CDs) are attracting increasing research attention due to their exceptional attributes, including their biocompatibility, water solubility, minimal toxicity, high photoluminescence, and easy functionalization. Green CDs, derived from natural sources such as fruits and vegetables, present advantages over conventionally produced CDs, such as cost-effectiveness, stability, simplicity, safety, and environmental friendliness. Various methods, including hydrothermal and microwave treatments, are used to synthesize green CDs, which demonstrate strong biocompatibility, stability, and luminescence. These properties give green CDs versatility in their biological applications, such as bioimaging, biosensing, and drug delivery. This review summarizes the prevalent synthesis methods and renewable sources regarding green CDs; examines their optical features; and explores their extensive biological applications, including in bioimaging, biosensing, drug/gene delivery, antimicrobial and antiviral effects, formatting of mathematical components, cancer diagnosis, and pharmaceutical formulations.

Maillard Reaction-Derived S-Doped Carbon Dots Promotes Downregulation of PPARγ, C/EBPα, and SREBP-1 Genes In-Vitro

Carbon nanodots (CDs) are commonly found in food products and have attracted significant attention from food scientists. There is a high probability of CD exposure in humans, but its impacts on health are unclear. Therefore, health effects associated with CD consumption should be investigated. In this study, we attempted to create a model system of the Maillard reaction between cystine and glucose using a simple cooking approach. The CDs (CG-CDs) were isolated from cystine-glucose-based Maillard reaction products and characterized using fluorescence spectroscopy, X-ray diffractometer (XRD), and transmission electron microscope (TEM). Furthermore, human mesenchymal stem cells (hMCs) were used as a model to unravel the CDs' cytotoxic properties. The physiochemical assessment revealed that CG-CDs emit excitation-dependent fluorescence and possess a circular shape with sizes ranging from 2 to 13 nm. CG-CDs are predominantly composed of carbon, oxygen, and sulfur. The results of the cytotoxicity evaluation indicate good biocompatibility, where no severe toxicity was observed in hMCs up to 400 μg/mL. The DPPH assay demonstrated that CDs exert potent antioxidant abilities. The qPCR analysis revealed that CDs promote the downregulation of the key regulatory genes, PPARγ, C/EBPα, SREBP-1, and HMGCR, coupled with the upregulation of anti-inflammatory genes. Our findings suggested that, along with their excellent biocompatibility, CG-CDs may offer positive health outcomes by modulating critical genes involved in lipogenesis, homeostasis, and obesity pathogenesis.

Effects of different roasting temperatures on rabbit meat protein oxidation and fluorescent carbon nanoparticle formation

This study explores the oxidation of rabbit meat proteins and the physicochemical properties of the resulting fluorescent carbon nanoparticles (CNPs) under various roasting temperatures (180, 210, 240, 270, and 300 °C). The determination of sulfhydryl content, along with the results from UV and fluorescence spectroscopy, indicates that the protein structure undergoes changes during the roasting process, and the degree of oxidation shows an increasing trend with rising roasting temperatures. The CNP solution obtained exhibits a typical blue fluorescence. Moreover, as the roasting temperature increases from 180 °C to 300 °C, the relative content of the three elements in CNPs, namely C, N, and O, increases by 12 %, -3%, and -9 %, respectively. The surface of the obtained rabbit meat CNPs contains hydrophilic and polycyclic groups, such as carbonyl, hydroxyl, and amide bonds. Correlation analysis reveals a significant positive correlation between the degree of protein oxidation and the fluorescence intensities of CNPs.

An overview on animal/human biomass-derived carbon dots for optical sensing and bioimaging applications

Over the past decade, carbon dots (CDs) have emerged as some of the extremely popular carbon nanostructures for diverse applications. The advantages of sustainable CDs, characterized by their exceptional photoluminescence (PL), high water solubility/dispersibility, non-toxicity, and biocompatibility, substantiate their potential for a wide range of applications in sensing and biology. Moreover, nature offers plant- and animal-derived precursors for the sustainable synthesis of CDs and their doped variants. These sources are not only readily accessible, inexpensive, and renewable but are also environmentally benign green biomass. This review article presents in detail the production of sustainable CDs from various animal and human biomass through bottom-up synthetic methods, including hydrothermal, microwave, microwave-hydrothermal, and pyrolysis methods. The resulting CDs exhibit a uniform size distribution, possibility of heteroatom doping, surface passivation, and remarkable excitation wavelength-dependent/independent emission and up-conversion PL characteristics. Consequently, these CDs have been successfully utilized in multiple applications, such as bioimaging and the detection of various analytes, including heavy metal ions. Finally, a comprehensive assessment is presented, highlighting the prospects and challenges associated with animal/human biomass-derived CDs for multifaceted applications.

An Overview of the Potential of Food-Based Carbon Dots for Biomedical Applications

Food-based carbon dots (CDs) hold significant importance across various fields, ranging from biomedical applications to environmental and food industries. These CDs offer unique advantages over traditional carbon nanomaterials, including affordability, biodegradability, ease of operation, and multiple bioactivities. This work aims to provide a comprehensive overview of recent developments in food-based CDs, focusing on their characteristics, properties, therapeutic applications in biomedicine, and safety assessment methods. The review highlights the potential of food-based CDs in biomedical applications, including antibacterial, antifungal, antivirus, anticancer, and anti-immune hyperactivity. Furthermore, current strategies employed for evaluating the safety of food-based CDs have also been reported. In conclusion, this review offers valuable insights into their potential across diverse sectors and underscores the significance of safety assessment measures to facilitate their continued advancement and application.

Carbon dots induce pathological damage to the intestine via causing intestinal flora dysbiosis and intestinal inflammation

BACKGROUND

Carbon dots (CDs), as excellent antibacterial nanomaterials, have gained great attention in treating infection-induced diseases such as periodontitis and stomatitis. Given the eventual exposure of CDs to the intestine, elucidating the effect of CDs on intestinal health is required for the safety evaluation of CDs.

RESULTS

Herein, CDs extracted from ε-poly-L-lysine (PL) were chosen to explore the modulation effect of CDs on probiotic behavior in vitro and intestinal remodeling in vivo. Results verify that PL-CDs negatively regulate Lactobacillus rhamnosus (L. rhamnosus) growth via increasing reactive oxygen species (ROS) production and reducing the antioxidant activity, which subsequently destroys membrane permeability and integrity. PL-CDs are also inclined to inhibit cell viability and accelerate cell apoptosis. In vivo, the gavage of PL-CDs is verified to induce inflammatory infiltration and barrier damage in mice. Moreover, PL-CDs are found to increase the Firmicutes to Bacteroidota (F/B) ratio and the relative abundance of Lachnospiraceae while decreasing that of Muribaculaceae.

CONCLUSION

Overall, these evidences indicate that PL-CDs may inevitably result in intestinal flora dysbiosis via inhibiting probiotic growth and simultaneously activating intestinal inflammation, thus causing pathological damage to the intestine, which provides an effective and insightful reference for the potential risk of CDs from the perspective of intestinal remodeling.

Nanoencapsulation Motivates the High Inhibitive Ability of Fucoxanthin on H2O2-Induced Human Hepatocyte Cell Line (L02) Apoptosis via Regulating Lipid Metabolism Homeostasis

This study reports an encapsulation system for fucoxanthin (FX) through simple affinity binding with gelatin (GE) and then coating with chitosan oligosaccharides (COS). The effects of FX before and after encapsulation on the human hepatocyte cell line (L02) were investigated. FX-GE and FX-GE-COS nanocomplexes exhibited a spherical shape with diameters of 209 ± 6 to 210 ± 8 nm. FX-GE-COS nanocomplexes were found to perform the best with the highest encapsulation efficiency (EE, 83.88 ± 4.39%), improved FX stability, and enhanced cellular uptake on the nanoscale. The cytotoxicity and cell mitochondrial damage of H₂O₂ exposure to L02 cells decreased with the increase of free-FX and FX-GE-COS nanocomplexes. FX-GE-COS nanocomplexes' intervention decreased the intracellular ROS and inhibited the apoptosis of L02 cells that was induced by H₂O₂ exposure in a concentration-dependent manner. Lipidomic analysis revealed that FX-GE-COS nanocomplexes could regulate the lipid metabolism disturbed by H₂O₂ and protected the mitochondrial function of L02 cells. These results suggested that nanoencapsulation enhanced the antioxidant activity of FX to L02 cells, and the constructed FX-GE-COS nanocomplexes have the potential to be an antioxidant nutritional dietary supplement.

Changes in the lipid profiles of hairtail (Trichiurus lepturus) muscle during air-drying via liquid chromatography-mass spectrometry analysis

Chemical and liquid chromatography-mass spectrometry (LC/MS)-based lipidomics analyses were performed to explore the alterations in lipid profiles in the hairtail muscle during air-drying. The peroxide value (POV) and carbonyl group value (CGV) in the air-dried hairtail (ADH) significantly increased with air-drying time. Lipidomics results revealed 1,326 lipids, which were grouped into 33 lipid categories, including 422 triglycerides (TGs), 170 phosphatidylcholines (PCs), 110 phosphatidylethanolamines (PEs), among others. In addition, ADH contained 131 and 201 differentially abundant lipids (DALs) at high and low levels, respectively. Among them, DALs, TGs, PCs, LPCs, and LPEs could be used to distinguish between ADH and FH samples. The apparent alterations in ADH and FH samples were attributed to lipid decomposition, side-chain modifications during oxidation, or oxygen- and salt-promoted lipid oxidation. Thus, this study provides a more comprehensive understanding of hairtail lipid profiles before and after air-drying which can be used as a guide for hairtail products.

Applications of lipidomics in goat meat products: Biomarkers, structure, nutrition interface and future perspectives

Goat meat, as a superior product including low lipids, low cholesterol contents and high-quality proteins, becomes the superior food for the national market. With the increasing demand for goat meat, the production, sensory quality and physicochemical properties of goat meat are also widely observed. Following significant discoveries on the mechanism determining goat meat quality, further research on complex and interactive factors leading to changes of goat meat quality is increasingly based on data-driven "omics" methods, such as lipidomics, which can rapidly identify and quantify >1000 lipid species at same time facilitating comprehensive analyses of lipids in tissues. Molecular mechanism and biomarkers indicating the changes of goat meat quality, authentication, meat analogue, nutrition and health by lipidomics are feasible. According to the analysis results of the classes and of different biomarkers lipids of goat meat quality, the main processes involved the biosynthesis of unsaturated fatty acids, associations with lipids and proteins, lipid oxidation, lipid hydrolysis, lipid degradation, lipid deposition and lipid denaturation, which have been translated into advanced technologies for identifying the goat meat adulteration and faux meat rapidly and accurately. SIGNIFICANCE: In this review, the research of lipidomics technology, past applications, recent findings and common on the recent advances of lipidomics in the quality assessment of mutton products by lipidomics with MS approaches have been summarized. The information reported in review can serve as a reference to characterize the lipids found in mutton, clarify the application of lipidomics to the field of mutton products and provide new perspectives in producing superior quality mutton products.

Effect of Lipids in Yak Muscle under Different Feeding Systems on Meat Quality Based on Untargeted Lipidomics

Simple Summary

With the development of living standards, consumers are paying more and more attention to meat quality and flavor. When consumers choose meat, they directly pay attention to meat quality and flavor, so the meat quality and flavor directly decide meat price and sales volume. Better meat quality and flavor are the crucial factors that increase the additional value of meat. Because of its special nutritional value and taste, yak meat is popular with consumers. The intramuscular lipids can greatly affect the meat quality and flavor, but there is no report on the effect of lipids in yak muscle on the meat quality and flavor. In this study, we studied the characterization of lipids in yak muscle under different feeding systems and further explored the key lipids affecting yak meat quality and flavor. This study can provide new insight into the improvement of yak meat quality and flavor.

Abstract

The effect of lipids on yak meat quality and volatile flavor compounds in yak meat under graze feeding (GF) and stall feeding (SF) was explored using untargeted lipidomics based on liquid chromatography–mass spectrometry (LC-MS) in this study. First, the volatile flavor compounds in longissimus dorsi (LD) of SF and GF yaks were detected by gas chromatography–mass spectrometry (GC-MS). In total 49 and 39 volatile flavor substances were detected in the LD of GF and SF yaks, respectively. The contents of pelargonic aldehyde, 3-hydroxy-2-butanone and 1-octen-3-ol in the LD of both GF and SF yaks were the highest among all detected volatile flavor compounds, and the leading volatile flavor substances in yak LD were aldehydes, alcohols and ketones. In total, 596 lipids were simultaneously identified in the LD of SF and GF yaks, and the leading lipids in the LD of both GF and SF yaks were sphingolipids (SPs), glycerolipids (GLs) and glycerophospholipids (GPs). Seventy-five significantly different lipids (SDLs) between GF and SF yaks were identified in the LD. The high content of TG(16:1/18:1/18:1), TG(16:0/17:1/18:1) and TG(16:0/16:1/18:1), PE(18:0/22:4) and PC(18:2/18:0) can improve the a* (redness) and tenderness of yak muscle. The changes in volatile flavor compounds in yak muscle were mainly caused by TG(18:1/18:1/18:2), TG(18:0/18:1/18:1), TG(16:0/17:1/18:1), TG(16:0/16:1/18:1), PC(18:2/18:0), TG(16:1/18:1/18:1), PI(18:0/20:4), TG(16:1/16:1-/18:1) and TG(17:0/18:1/18:1). The above results provide a theoretical basis for improving yak meat quality from the perspective of intramuscular lipids.

UPLC-MS-MS-based lipidomics for the evaluation of changes in lipids during dry-cured mutton ham processing

Six key stages in the processing of dry-cured muton ham were selected, and changes in the main lipid metabolites as well as the major pathways involved were identified using a lipidic metabolomics approach based on UPLC-MS-MS. In total, 581 lipid metabolites from 22 subclasses were identified, including 521 significantly differential lipids (p < 0.05, VIP > 1). Glycerolipids (GL) were the most abundant lipids, followed by glycerophospholipids (GP), fatty acyls (FA), and sphingolipids (SL). PCA and OPLS-DA of metabolites showed that the quality of mutton ham changed the most during the P3 fermenting stage, including TG(18:1/18:2/18:3), PE(20:5/18:1), and TG(16:1/18:1/18:4) that were significantly downregulated, and CE(20:3), FFA(24:6), LPC(20:3/0:0), and FFA(18:4) that were significantly upregulated. Moreover, glycerophospholipid metabolism and sphingolipid metabolism were the key metabolic pathways involved in the processing of dry-cured mutton ham. Our results provide a basis for quality control and product improvement of dry-cured mutton ham.

Carbon dots synthesized from microorganisms and food by-products: active and smart food packaging applications

Nanotechnology is rapidly becoming a commercial reality for application in food packaging. In particular, the incorporation of nanoparticles into packaging materials is being used to increase the shelf life and safety of foods. Carbon dots (C-dots) have a diverse range of potential applications in food packaging. They can be synthesized from environmentally friendly sources such as microorganisms, food by-products, and waste streams, or they may be generated in foods during normal processing operations, such as cooking. These processes often produce nitrogen- and sulfur-rich heteroatom-doped C-dots, which are beneficial for certain applications. The incorporation of C-dots into food packaging materials can improve their mechanical, barrier, and preservative properties. Indeed, C-dots have been used as antioxidant, antimicrobial, photoluminescent, and UV-light blocker additives in food packaging materials to reduce the chemical deterioration and inhibit the growth of pathogenic and spoilage microorganisms in foods. This article reviews recent progress on the synthesis of C-dots from microorganisms and food by-products of animal origin. It then highlights their potential application for the development of active and intelligent food packaging materials. Finally, a discussion of current challenges and future trends is given.