Vitamin C-Protective Role in Oxidative Stress Conditions Induced in Human Normal Colon Cells by Label-Free Raman Spectroscopy and Imaging

Raman-AFM-fluorescence-guided impact of linoleic and eicosapentaenoic acids on subcellular structure and chemical composition of normal and cancer human colon cells

The regular overconsumption of high-energy food (rich in lipids and sugars) results in elevated nutrient absorption in intestine and consequently excessive accumulation of lipids in many organs e.g.: liver, adipose tissue, muscles. In the long term this can lead to obesity and obesity-associated diseases e.g. type 2 diabetes, non-alcoholic fatty liver disease, cardiovascular disease, inflammatory bowel disease (IBD). In the presented paper based on RI data we have proved that Raman maps can be used successfully for subcellular structures visualization and analysis of fatty acids impact on morphology and chemical composition of human colon single cells - normal and cancer. Based on Raman data we have investigated the changes related to endoplasmic reticulum, mitochondria, lipid droplets and nucleus. Analysis of ratios calculated based on Raman bands typical for proteins (1256, 1656 cm-1), lipids (1304, 1444 cm-1) and nucleic acids (750 cm-1) has confirmed for endoplasmic reticulum the increased activity of this organelle in lipoproteins synthesis upon FAs supplementation; for LDs the changes of desaturation of accumulated lipids with the highest unsaturation level for CaCo-2 cells upon EPA supplementation; for mitochondria the stronger effect of FAs supplementation was observed for CaCo-2 cells confirming the increased activity of this organelle responsible for energy production necessary for tumor development; the weakest impact of FAs supplementation was observed for nucleus for both types of cells and both types of acids. Fluorescence imaging was used for the investigations of changes in LDs/ER morphology. Our measurements have shown the increased area of LDs/ER for CaCo-2 cancer cells, and the strongest effect was noticed for CaCo-2 cells upon EPA supplementation. The increased participation of lipid structures for all types of cells upon FAs supplementation has been confirmed also by AFM studies. The lowest YM values have been observed for CaCo-2 cells including samples treated with FAs.

Combined exposure of polystyrene microplastics and benzo[a]pyrene in rat: Study of the oxidative stress effects in the liver

Microplastics (MPs) and benzo[a]pyrene (B[a]P) are prevalent environmental pollutants. Numerous studies have extensively reported their individual adverse effects on organisms. However, the combined effects and mechanisms of exposure in mammals remain unknown. Thus, this study aims to investigate the potential effects of oral administration of 0.5μm polystyrene (PS) MPs (1 mg/mL or 5 mg/mL), B[a]P (1 mg/mL or 5 mg/mL) and combined (1 mg/mL or 5 mg/mL) on 64 male SD rats by gavage method over 6-weeks. The results demonstrate that the liver histopathological examination showed that the liver lobules in the combined (5 mg/kg) group had blurred and loose boundaries, liver cord morphological disorders, and significant steatosis. The levels of AST, ALT, TC, and TG in the combined dose groups were significantly higher than those in the other groups, the combined (5 mg/kg) group had the lowest levels of antioxidant enzymes and the highest levels of oxidants. The expression of Nrf2 was lowest and the expression of P38, NF-κB, and TNF-α was highest in the combined (5 mg/kg) group. In conclusion, these findings indicate that the combination of PSMPs and B[a]P can cause the highest levels of oxidative stress and elicit markedly enhanced toxic effects, which cause severe liver damage.

The Effect of β-Carotene, Tocopherols and Ascorbic Acid as Anti-Oxidant Molecules on Human and Animal In Vitro/In Vivo Studies: A Review of Research Design and Analytical Techniques Used

Prolonged elevated oxidative stress (OS) possesses negative effect on cell structure and functioning, and is associated with the development of numerous disorders. Naturally occurred anti-oxidant compounds reduce the oxidative stress in living organisms. In this review, antioxidant properties of β-carotene, tocopherols and ascorbic acid are presented based on in vitro, in vivo and populational studies. Firstly, environmental factors contributing to the OS occurrence and intracellular sources of Reactive Oxygen Species (ROS) generation, as well as ROS-mediated cellular structure degradation, are introduced. Secondly, enzymatic and non-enzymatic mechanism of anti-oxidant defence against OS development, is presented. Furthermore, ROS-preventing mechanisms and effectiveness of β-carotene, tocopherols and ascorbic acid as anti-oxidants are summarized, based on studies where different ROS-generating (oxidizing) agents are used. Oxidative stress biomarkers, as indicators on OS level and prevention by anti-oxidant supplementation, are presented with a focus on the methods (spectrophotometric, fluorometric, chromatographic, immuno-enzymatic) of their detection. Finally, the application of Raman spectroscopy and imaging as a tool for monitoring the effect of anti-oxidant (β-carotene, ascorbic acid) on cell structure and metabolism, is proposed. Literature data gathered suggest that β-carotene, tocopherols and ascorbic acid possess potential to mitigate oxidative stress in various biological systems. Moreover, Raman spectroscopy and imaging can be a valuable technique to study the effect of oxidative stress and anti-oxidant molecules in cell studies.

Mevastatin in colon cancer by spectroscopic and microscopic methods - Raman imaging and AFM studies

One of the most important areas of medical science is oncology, which is responsible for both the diagnostics and treatment of cancer diseases. Simultaneously one of the main challenges of oncology is the development of modern drugs effective in the fight against cancer. Statins are a group of biologically active compounds with the activity of 3-hydroxy-3-methyl glutaryl-CoA reductase inhibitors, an enzyme catalyzing the reduction of 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) to mevalonic acid. By acting on this enzyme, statins inhibit the endogenous cholesterol synthesis which in turn causes the reduction of its systemic concentrations. However, in vitro and in vivo studies confirm also the cytostatic and cytotoxic effects of statins against various types of cancer cells including colon cancer. In the presented studies the influence of mevastatin on cancerous colon cells CaCo-2 by Raman spectroscopy and imaging is discussed and compared with biochemistry characteristic for normal colon cells CCD-18Co. Based on vibrational features of colon cells: normal cells CCD-18Co, cancerous cells CaCo-2 and cancerous cells CaCo-2 treated by mevastatin in different concentrations and incubation times we have confirmed the influence of this statin on biochemistry composition of cancerous human colon cells. Moreover, the spectroscopic results for colon normal cells and cancerous cells based on data typical for nucleic acids, proteins, lipids have been compared. The cytotoxisity of mevastatin was determined by using XTT tests.