Usnic acid induced changes in biomolecules and their association with apoptosis in squamous carcinoma (A-431) cells: A flow cytometry, FTIR and DLS spectroscopic study

Many natural products induce apoptotic cell death in cancer cells, though studies on their interactions with macromolecules are limited. For the first time, this study demonstrated the cytotoxic potential of usnic acid (UA) against squamous carcinoma (A-431) cells and the associated changes in cell surface proteins, lipids and DNA by attenuated total reflection- fourier transform infrared spectroscopy (ATR-FTIR) and dynamic light scattering (DLS) spectroscopic studies. The IC₅₀ for UA was 98.9 µM after treatment of A-431 cells for 48 h, while the IC₅₀ reduced to 39.2 µM after 72 h of incubation time. UA induced oxidative stress in treated cells as confirmed by DCFHDA flow cytometry assay, depletion in reduced glutathione and increase in lipid peroxidation. The oxidative stress resulted in conformation change in amide I, amide II protein bands and DNA as observed by ATR-FTIR in UA treated A-431 cells. Shift in secondary structures of proteins from α helix to β sheets and structural changes in DNA was observed in UA treated A-431 cells. An increase in the band intensity of phospholipids, increased distribution of lipid and change in membrane potential was noted in UA treated cells, which was confirmed by externalization of phosphatidylserine to the outer membrane by annexin V-FITC/PI assay. Increase in mitochondrial membrane potential, cell cycle arrest at G0/G1 phase by flow cytometry and activation of caspase-3/7 dependent proteins confirmed the UA induced apoptosis in treated A-431 cells. FTIR and DLS spectroscopy confirmed the changes in biomolecules after UA treatment, which were associated with apoptosis, as observed by flow cytometry.

Spectroscopic Evaluation of the Potential Neurotoxic Effects of a New Candidate for Anti-Seizure Medication-TP-315 during Chronic Administration (In Vivo)

The aim of this study was to investigate the potential neurotoxic effect of the new anti-seizure medication candidate—5-(3-chlorophenyl)-4-hexyl-2,4-dihydro-3H-1,2,4-triazole-3-thione (TP-315), after chronic administration to mice. TP-315 was administered to mice intraperitoneally for 14 days. At 24 h post the last injection, animals were decapitated, their brains were acquired, flash-frozen in liquid nitrogen and cut into 10 µm slices. The FT-IR chemical imaging technique was used for the investigation of the potential neurotoxic effect in the cerebral cortex and hippocampus. The effect on the lipidomic and proteomic profile and on oxidative stress was investigated. The results showed no statistically significant changes in the above-mentioned parameters. TP-315 seems to pose no neurotoxic effect on the mouse brain after chronic use, therefore, its use should be safe.

Non-noble metallic Cu with three different roles in a Cu doped ZnO/Cu/g-C3N4 heterostructure for enhanced Z-scheme photocatalytic activity

Cu serves as a co-catalyst, an electron mediator, and a dopant leading to a high enhancement in the photocatalytic activity of Cu-ZnO/Cu/g-C₃N₄ Z-scheme photocatalyst.

Investigation of gene expressions in differentiated cell derived bone marrow stem cells during bone morphogenetic protein-4 treatments with Fourier transform infrared spectroscopy

A model was set up to predict the differentiation patterns based on the data extracted from FTIR spectroscopy. For this reason, bone marrow stem cells (BMSCs) were differentiated to primordial germ cells (PGCs). Changes in cellular macromolecules in the time of 0, 24, 48, 72, and 96h of differentiation, as different steps of the differentiation procedure were investigated by using FTIR spectroscopy. Also, the expression of pluripotency (Oct-4, Nanog and c-Myc) and specific genes (Mvh, Stella and Fragilis) were investigated by real-time PCR. However, the expression of genes in five steps of differentiation was predicted by FTIR spectroscopy. FTIR spectra showed changes in the template of band intensities at different differentiation steps. There are increasing changes in the stepwise differentiation procedure for the ratio area of CH2, which is symmetric to CH2 asymmetric stretching. An ensemble of expert methods, including regression tree (RT), boosting algorithm (BA), and generalized regression neural network (GRNN), was the best method to predict the gene expression by FTIR spectroscopy. In conclusion, the model was able to distinguish the pattern of different steps from cell differentiation by using some useful features extracted from FTIR spectra.

Tianeptine, olanzapine and fluoxetine show similar restoring effects on stress induced molecular changes in mice brain: An FT-IR study

Chronic stress which can cause a variety of disorders and illness ranging from metabolic and cardiovascular to mental leads to alterations in content, structure and dynamics of biomolecules in brain. The determination of stress-induced changes along with the effects of antidepressant treatment on these parameters might bring about more effective therapeutic strategies. In the present study, we investigated unpredictable chronic mild stress (UCMS)-induced changes in biomolecules in mouse brain and the restoring effects of tianeptine (TIA), olanzapine (OLZ) and fluoxetine (FLX) on these variations, by Fourier transform infrared (FT-IR) spectroscopy. The results revealed that chronic stress causes different membrane packing and an increase in lipid peroxidation, membrane fluidity. A significant increment for lipid/protein, C=O/lipid, CH3/lipid, CH2/lipid, PO(-)2/lipid, COO(-)/lipid and RNA/protein ratios but a significant decrease for lipid/protein ratios were also obtained. Additionally, altered protein secondary structure components were estimated, such as increment in random coils and beta structures. The administration of TIA, OLZ and FLX drugs restored these stress-induced variations except for alterations in protein structure and RNA/protein ratio. This may suggest that these drugs have similar restoring effects on the consequences of stress activity in brain, in spite of the differences in their action mechanisms. All findings might have importance in understanding molecular mechanisms underlying chronic stress and contribute to studies aimed for drug development.

In situ biospectroscopic investigation of rapid ischemic and postmortem induced biochemical alterations in the rat brain

Rapid advances in imaging technologies have pushed novel spectroscopic modalities such as Fourier transform infrared spectroscopy (FTIR) and X-ray absorption spectroscopy (XAS) at the sulfur K-edge to the forefront of direct in situ investigation of brain biochemistry. However, few studies have examined the extent to which sample preparation artifacts confound results. Previous investigations using traditional analyses, such as tissue dissection, homogenization, and biochemical assay, conducted extensive research to identify biochemical alterations that occur ex vivo during sample preparation. In particular, altered metabolism and oxidative stress may be caused by animal death. These processes were a concern for studies using biochemical assays, and protocols were developed to minimize their occurrence. In this investigation, a similar approach was taken to identify the biochemical alterations that are detectable by two in situ spectroscopic methods (FTIR, XAS) that occur as a consequence of ischemic conditions created during humane animal killing. FTIR and XAS are well suited to study markers of altered metabolism such as lactate and creatine (FTIR) and markers of oxidative stress such as aggregated proteins (FTIR) and altered thiol redox (XAS). The results are in accordance with previous investigations using biochemical assays and demonstrate that the time between animal death and tissue dissection results in ischemic conditions that alter brain metabolism and initiate oxidative stress. Therefore, future in situ biospectroscopic investigations utilizing FTIR and XAS must take into consideration that brain tissue dissected from a healthy animal does not truly reflect the in vivo condition, but rather reflects a state of mild ischemia. If studies require the levels of metabolites (lactate, creatine) and markers of oxidative stress (thiol redox) to be preserved as close as possible to the in vivo condition, then rapid freezing of brain tissue via decapitation into liquid nitrogen, followed by chiseling the brain out at dry ice temperatures is required.

Cardiolipin plays a role in KCN-induced necrosis

Cardiolipin (CL) is a unique anionic, dimeric phospholipid found almost exclusively in the inner mitochondrial membrane and is essential for the function of numerous enzymes that are involved in mitochondrial energy metabolism. While the role of cardiolipin in apoptosis is well established, its involvement in necrosis is enigmatic. In the present study, KCN-induced necrosis in U937 cells was used as an experimental model to assess the role of CL in necrosis. KCN addition to U937 cells induced reactive oxygen species (ROS) formation, while the antioxidants inhibited necrosis, indicating that ROS play a role in KCN-induced cell death. Further, CL oxidation was confirmed by the monomer green fluorescence of 10-N-nonyl acridine orange (NAO) and by TLC. Utilizing the red fluorescence of the dimeric NAO, redistribution of CL in mitochondrial membrane during necrosis was revealed. We also showed that the catalytic activity of purified adenosine triphosphate (ATP) synthase complex, known to be modulated by cardiolipin, decreased following KCN treatment. All these events occurred at an early phase of the necrotic process prior to rupture of the cell membrane. Furthermore, CL-deficient HeLa cells were found to be resistant to KCN-induced necrosis as compared with the wild type cells. We suggest that KCN, an effective reversible inhibitor of cytochrome oxidase and thereby of the respiratory chain leads to ROS increase, which in turn oxidizes CL (amongst other membrane phospholipids) and leads to mitochondrial membrane lipid reorganization and loss of CL symmetry. Finally, the resistance of CL-deficient cells to necrosis further supports the notion that CL, which undergoes oxidation during necrotic cell death, is an integral part of the milieu of events taking place in mitochondria leading to membrane disorganization and mitochondrial dysfunction.

Determination of simvastatin-induced changes in bone composition and structure by Fourier transform infrared spectroscopy in rat animal model

Simvastatin is a hypolipidemic drug which is used to control hypercholesterolemia and to prevent cardiovascular disease. In the current study, the effects of high and low doses of simvastatin treatment on tibia of healthy rats were investigated. Wistar rats were used for the control, 20mg and 50mg simvastatin-treated groups. Molecular investigations were performed using Fourier transform infrared spectroscopy. In the bones of the two groups of simvastatin-treated rats, the relative mineral/matrix ratio (p<0.001), relative carbonate content (p<0.001), carbonate/amide I ratio (p<0.001) and crystallinity (p<0.001) decreased significantly compared to the control group. Low dose of simvastatin treatment is more effective in reducing the relative carbonate content indicating the amount of carbonate substitution for phosphate in the mineral crystal. The olefinic band almost disappeared in the high dose of simvastatin-treated group which implies a decrease in unsaturation and an increase in lipid peroxidation. The higher frequency value and the bandwidth of CH(2) asymmetric stretching band for the 50mg treated group imply more disordered (p<0.001) and fluid (p<0.001) membrane structure. Low dose of simvastatin is more effective in strengthening the bone than high dose simvastatin treatment. High dose simvastatin treatment induces lipid peroxidation and changes the lipid composition and concentration, which are known to affect membrane physical properties.