Identifying the Responses from the Estrogen Receptor-Expressed MCF7 Cells Treated in Anticancer Drugs of Different Modes of Action Using Live-Cell FTIR Spectroscopy

Infrared spectroscopy and flow cytometry studies on the apoptotic effect of nano-chrysin in HeLa cells

Mapping the structural changes in membrane lipids, proteins, polysaccharides and nucleic acids has opened new channels for understanding the mode of action of anticancer natural products. Earlier, we synthesized chrysin nanoparticles (NChr) with good bioavailability, and characterized its size, surface charge, entrapment efficiency, and drug release pattern using PLGA polymer. NChr induced concentration dependent cytotoxicity in HeLa cells with an IC₅₀ of 61.54 ± 1.2 µM in comparison with free chrysin with IC₅₀ of 86.51 ± 2.9 µM. Since nanoparticles interact dynamically with cell membranes, organelles, proteins and DNA, it is necessary to understand the interplay of nanodrug induced macromolecular changes in cancer cells. In this work, we obtained signatures of NChr-induced biochemical changes in HeLa cells by Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy technique coupled with flow cytometry. NChr induced cell membrane disruption, G1 phase cell cycle arrest, and increased externalization of phosphatidylserine leading to apoptosis indicating the biochemical perturbations in membrane lipids and DNA of HeLa cells in comparison with untreated cells. The 1300-1000 cm^-1 spectral region indicated NChr interaction with the ribose sugar backbone and DNA denaturation. Spectral range 1800-1400 cm^-1 indicated a concentration dependent decrease in α helical and β sheet structures which may lead to protein degradation during apoptosis. The spectral range 3000-2800 cm^-1 indicated the lipid peroxidation in response to NChr treatment. This is the first study describing the bio-macromolecular changes induced by a nano encapsulated drug and can pave the way to investigate unconventional modes of action for bioactive formulations.

Hydroxycinnamic acid derivatives effect on hypercholesterolemia, comparison with ezetimibe: Permeability assays and FTIR spectroscopy on Caco-2 cell line

High blood cholesterol levels may increase the risk of developing atherosclerosis. Since intestinal cholesterol absorption plays a major role in maintaining total body cholesterol homeostasis, the aim of the present study was to compare the effect of ezetimibe and three hydroxycinnamic acid derivatives (rosmarinic acid, chlorogenic acid and m-coumaric acid) that are present in several medicinal plants on cholesterol absorption in the intestinal Caco-2 ​cells. In addition to the permeability assays, studies on alteration of the biochemical properties of Caco-2 ​cells under the effect of ezetimibe and hydroxycinnamic acid derivatives was evaluated using FTIR accompanied with multivariate analysis by PCA. The cholesterol permeability assays showed that these compounds could decrease cholesterol permeability with a percentage ranging from 76.98 to 96.6% with the highest inhibition for ezetimibe. whereas the FTIR studies didn't show similar changes between ezetimibe and the three hydroxycinnamic acid derivatives in protein and nucleic acids region, suggesting that these compounds have hypocholesterolemic effect. Nevertheless, each compound originated a different change on Caco-2 treated cells suggesting a different mode of action.

•

Hydroxycinnamic acid derivatives and ezetimibe permeated the intestinal barrier.

•

Hydroxycinnamic acid derivatives decreased cholesterol permeability.

•

Hydroxycinnamic acid derivatives could affect the cell components.

•

PCA of FTIR spectra showed differences on protein and nucleic acid regions.

In vitro Fourier transform infrared spectroscopic study of the effect of glycerol on the uptake of beclomethasone dipropionate in living respiratory cells

The quantification of drug in living cells is of increasing interest in pharmaceutical research because of its importance in understanding drug efficacy and toxicity. Label-free in situ measurement methods are advantageous for their ability to obtain chemical and time profiles without the need of labelling or extraction steps. We have previously shown that Fourier transform infrared (FTIR) spectroscopy has the potential to quantify drug in situ within living cells at micromolar level when a simple solution of drug was added to the medium. The purpose of this study was to demonstrate that the approach can evaluate more complex systems such as the effect of membrane modification by a formulation on drug uptakes. The inhaled corticosteroid, beclomethasone dipropionate (BDP), in Calu-3 respiratory epithelial cells in the absence and presence of glycerol, an excipient in some inhaled medicines was used as the model system. The FTIR method was first validated for limit of detection (LOD) and quantification (LOQ) according to published guidelines and the LOQ was found to be ∼ 20 μM, good enough to quantify BDP in the living cell. The uptake of BDP by living Calu-3 cells was found to be reduced in the presence of glycerol as expected due to the stiffening of the cell membrane by the presence of glycerol in the formulation. This study demonstrates the valuable analytical capability of live-cell FTIR to study the effect of formulation on drug transport in lungs and to evaluate drug availability to intracellular targets. We conclude that FTIR has potential to contribute widely at the frontier of live-cell studies.

Phytochemical profiling of Azima tetracantha Lam. leaf methanol extract and elucidation of its potential as a chain-breaking antioxidant, anti-inflammatory and anti-proliferative agent

Azima tetracantha, a traditional medicinal plant included in the order Brassicales and family Salvadoraceae, is widely used as a dietary supplement in folklore medicines. The plant is also used for the treatment of rheumatism, diarrhea and other inflammatory disorders. The present investigation focused on the phytochemical composition, radical scavenging, reducing potential and anti-proliferative activities of the A. tetracantha leaves. Quantitative estimation of the polyphenols and flavonoids revealed significantly elevated levels in the methanol extract. Corroborating with this, methanol extract exhibited higher in vitro anti-radical scavenging effect against 2,2-diphenyl-1- picrylhydrazyl (34.14 ± 2.19 μg/mL), and hydrogen peroxide (44.96 ± 1.77 μg/mL), as well as ferric reducing properties (58.24 ± 6.98 μg/mL). The methanolic extract also showed strong lipoxygenase (71.42 ± 6.36 μg/mL) and nitric oxide inhibitory activities (94.23 ± 8.11 μg/mL). Cytotoxic activity against MCF7 cells was found to be higher (IC50= 37.62 ± 2.94 μg/mL), than that of MDAMB231 cells (IC50= 69.11 ± 5.02 μg/mL). The qPCR-based analysis indicated dose-dependent increase in the expression of the pro-apoptotic genes such as executioner caspases and apoptotic protease activating factor-1. Overall, the results indicated the possible use of methanol extract of A. tetracantha leaves as a chain-breaking antioxidant molecule and are capable of inhibiting inflammatory enzymes and the proliferative potential of breast cancer cells.

Molecular-level changes induced by hydroxycinnamic acid derivatives in HepG2 cell line: Comparison with pravastatin

Hydroxycinnamic acid derivatives are an important class of polyphenols found in fruits, vegetables, and medicinal plants and widely consumed in human diet. In the present work, alterations of HepG2 cells biochemical profile under the effect of four hydroxycinnamic acid derivatives (caffeic acid, m-coumaric acid, chlorogenic acid and rosmarinic acid) relatively to the effect of pravastatin, a drug often prescribed to inhibit HMG-CoA reductase enzyme, the regulator enzyme in the cholesterol biosynthesis pathway, were reported. The application of FTIR spectroscopy in combination with multivariate analysis by PCA showed a similarity between pravastatin and the four hydroxycinnamic acid derivatives in metabolite profile modification expressed by various changes in proteins region, the phosphate region which mainly corresponds to nucleic acids as well as in lipids regions. FTIR structural analysis in the amide I region, using resolution enhancement methods, such as second derivative and amide I deconvolution method, revealed significant decrease in α-helix/random coil and intermolecular β-sheet decreased while intramolecular β-sheet in treated cells showed an increase. It was also noticed that the intracellular cholesterol as well as esterified ingredients such as cholesterol esters in the cell membrane decreased. Moreover, principal component analysis (PCA) of the spectral data showed that the compounds and pravastatin were well separated from untreated cells showing a different mode of action on HepG2 treated cells for each compound.

Live-cell ATR-FTIR spectroscopy as a novel bioanalytical tool for cell glucose metabolism research

Current novel drug developments for the treatment of diabetes require multiple bioanalytical assays to interrogate the cellular metabolism, which are costly, laborious and time-consuming. Fourier-transform infrared (FTIR) spectroscopy is a nondestructive, label-free, sensitive and low-cost technique that is recently found to be suitable for studying living cells. The aim of this study is to demonstrate that live-cell FTIR can be applied to study the differences in glucose metabolism in cells in normal culturing medium and cells treated in high glucose (a diabetes model) in order to highlight the potential of the technique in diabetes research. Live HepG2 cells were treated in normal glucose (3.8 mM; control) or high glucose (25 mM) medium and were measured directly using the FTIR approach. Principal component analysis was used to highlight any possible correlated changes 24, 48 and 72 h after treatments. FTIR spectra of live cell treated in normal and high glucose medium have shown significant differences (p < 0.05) for all treatment time. The control cells have seen an increased in the absorbance at 1088, 1240 and 1400 cm^-1, which are associated with phosphate stretching mode vibrations from phosphorylated proteins and DNA back bone; and symmetric stretching mode vibration of COO^- from fatty acids, amino acids, lipids and carbohydrate metabolites. However, the high glucose treated cells have shown a different changes in the 1000-1200 cm^-1 region, which is linked to the glycogen and ATP:ADP ratio. In conclusion, live-cell FTIR can be a low-cost method for the studies of metabolic changes in cells.

Cytotoxicity of Seaweed Compounds, Alone or Combined to Reference Drugs, against Breast Cell Lines Cultured in 2D and 3D

Seaweed bioactive compounds have shown anticancer activities in in vitro and in vivo studies. However, tests remain limited, with conflicting results, and effects in combination with anticancer drugs are even scarcer. Here, the cytotoxic effects of five seaweed compounds (astaxanthin, fucoidan, fucosterol, laminarin, and phloroglucinol) were tested alone and in combination with anticancer drugs (cisplatin-Cis; and doxorubicin-Dox), in breast cell lines (three breast cancer (BC) subtypes and one non-tumoral). The combinations revealed situations where seaweed compounds presented potentiation or inhibition of the drugs' cytotoxicity, without a specific pattern, varying according to the cell line, concentration used for the combination, and drug. Fucosterol was the most promising compound, since: (i) it alone had the highest cytotoxicity at low concentrations against the BC lines without affecting the non-tumoral line; and (ii) in combination (at non-cytotoxic concentration), it potentiated Dox cytotoxicity in the triple-negative BC cell line. Using a comparative approach, monolayer versus 3D cultures, further investigation assessed effects on cell viability and proliferation, morphology, and immunocytochemistry targets. The cytotoxic and antiproliferative effects in monolayer were not observed in 3D, corroborating that cells in 3D culture are more resistant to treatments, and reinforcing the use of more complex models for drug screening and a multi-approach that should include histological and ICC analysis.