Comparison of near-infrared (NIR) and mid-infrared (MIR) spectroscopy based on chemometrics for saffron authentication and adulteration detection.

In this work, the potential of near-infrared (NIR) and mid-infrared (MIR) spectroscopy along with chemometrics was investigated for authentication and adulteration detection of Iranian saffron samples. First, authentication of one-hundred saffron samples was examined by principal component analysis (PCA). The results showed the NIR spectroscopy can better predict the origin of samples than the MIR. Next, partial least squares-discriminant analysis (PLS-DA) was developed to detect four common plant-derived adulterants (i.e., saffron style, calendula, safflower, and rubia). In all cases, PLS-DA classification figures of merit in terms of sensitivity, specificity, error rate and accuracy were satisfactory for both NIR and MIR datasets. The built models were then successfully validated using test set and also commercial samples. Finally, partial least squares regression (PLSR) was used to estimate the amount of adulteration. In this case, only NIR showed a good performance with regression coefficients (R2) in range of 0.95-0.99.

FTIR bio-spectroscopy scattering correction using natural biological characteristics of different cell lines.

Fourier transform infrared (FTIR) spectroscopy is a well-known method of analysis, with various applications, including promising potential for analyzing biological samples. In the bio-spectroscopy of cells, Mie scattering may increase, which then causes spectral distortion, due to the similarity of cell size with the IR medium-wavelength. These changes make the spectrum unreliable. In previous scattering elimination studies, questionable estimations were considered. For instance, all cells were considered as spherical objects or cell size was estimated randomly. In an attempt to provide the best equation based on the natural existence of cells for the FTIR Mie scattering correction, we examined the actual biological data of cells - as opposed to those yielded from mathematical manipulations. So five biological factors: cell size, shape, granularity, circularity, and edge irregularities, for each cell line were considered as factors which cause scattering. For measuring cell size, roundness and edge irregularity, microscopy images were obtained and processed. For evaluating cell line granularity, flow cytometry was used. Finally, by including these factors, an algorithm was designed. To assess the accuracy of the proposed algorithm, the trypsinized cell spectrum was considered as the high scattering spectrum. Cells were also cultured on a MirrIR slide, and their ATR-FTIR spectrum was considered as the minimum scattering spectrum. The algorithm using the abovementioned five characteristics was used for 13 different cell lines, and in some cases the corrected spectrum demonstrated more than 97% resemblance with the ATR spectra of the same cells. A comparison between the results of this algorithm with the Bassan et al. (2017) algorithm for scattering correction that is freely available on the Internet was then conducted on two different cell lines, clearly showing the advantages of our algorithm, in terms of accuracy and precision. Therefore, this method can be viewed as a more suitable solution for scattering correction in cell investigations.

Cellular glutathione level does not predict ovarian cancer cells' resistance after initial or repeated exposure to cisplatin.

OBJECTIVE: Cisplatin resistance development is a major obstacle in ovarian cancer treatment. One of the most important mechanisms underlying cisplatin resistance is drug detoxification by glutathione. In the present study, the importance of initial or repeated exposure to cisplatin in glutathione dependent resistance was investigated. To this purpose, some cisplatin sensitive and resistant variants of human ovarian cancer cell lines providing an appropriate range of cisplatin sensitivity were selected. Clonogenic survival assay was performed to evaluate cisplatin resistance and intracellular contents of reduced (GSH) and oxidized (GSSG) glutathione were analyzed using an HPLC method. Our results indicated that the intracellular GSH and GSSG concentrations were nearly equal in A2780 and A2780CP cells, while the A2780CP cells showed 14 times more resistance than the A2780 cells after initial exposure to cisplatin. A2780-R1 and A2780-R3 cells which have been repeatedly exposed to cisplatin also showed no significant difference in glutathione content, even though A2780-R3 was about two times more resistant than A2780-R1. Moreover, intracellular GSH/GSSG ratio decreased in the resistant cells, reflecting a shift towards a more oxidizing intracellular environment indicative of oxidative stress. CONCLUSION: As a conclusion, it seems that although the intracellular glutathione concentration increases after repeated exposure to cisplatin, there is no clear correlation between the intracellular GSH content in ovarian cancer cells and their resistance to cisplatin neither after initial nor after repeated exposure to this drug.

Human Lung Carcinoma Reaction against Metabolic Serum Deficiency Stress.

Cancer treatment is still of the greatest challenges that health care providers and patients are facing. One of the unsolved problems in cancer treatment is cells' reaction to metabolic stress caused by harsh nutritional conditions around tumor. In order to be able to treat this disease properly, it is important to understand the true nature of the disease. In fact, the cells inside the central part of the tumor lack sufficient access to blood vessels, nutrients, and growth signals. After tumor shrinkage, the cells are exposed to favorable environmental conditions and might regrow and cause tumor recurrence. The main purpose of this study was to investigate the effect of serum starvation, as a type of metabolic stress, on human lung cancer cell line, A549. These cells were treated with 10% (control), 0.5% and 0.25% serum for 1 to 5 days. At 24 h intervals, the cells were released with 10% serum supplemented media. Starved or released cells were studied for their cycle and morphology. The results showed that the cells were actually arrested at G1 phase and following exposure to optimal conditions, the cells could be back to their cycle again. Furthermore, sub-G1 apoptotic cells population was not increased within the starvation period, while control cells had significant increase in sub-G1 cells. Morphological studies also showed that starved cells could make denser colonies while control cells were entering death phase. These observations provide some evidence for the generation of some effective resistance phenomena in cancer cells against harsh metabolic conditions.

Intracellular GSH Alterations and Its Relationship to Level of Resistance following Exposure to Cisplatin in Cancer Cells.

One of the major complications in cancer chemotherapy with cisplatin as one of the important medicines in treatment regimens of different cancers is the development of resistance. One of the most described cellular defense mechanisms involved in resistance is glutathione (GSH), thus in this study, the effects of cisplatin on the total intracellular GSH level (GSHi) in some sensitive and resistant variants of human cell lines (hepatocarcinoma HepG2, skin A375, cisplatin sensitive glioblastoma U373MG and cisplatin resistant glioblastoma U373MGCP, cisplatin sensitive ovary A2780S and cisplatin resistant A2780CP cells) were studied. MTT assay was performed to measure cytotoxicity of cisplatin (33.3 µM for 1 hour). Following cisplatin exposure, GSHi (per million cells) was evaluated using a photometrical assay up to 90 minutes. Our results indicate that there are significant differences between GSHi content of A2780CP and U373MGCP cells compared to other cell lines. Moreover, IC50 of cisplatin in different cells seems to have a relation with mean of GSH level in 90 minutes (GSH (mean)90). As a conclusion, it seems that resistance to cisplatin in different cell lines is more related with the diverse patterns of GSHi variations following cisplatin exposure than its original level, and/or its cellular increase or decrease. It is also suggested that GSH (mean)90 may be used as a factor for the prediction of cellular resistance to cisplatin.