Intermediate steatosis exhibited an increase in glycogen amount and major changes in lipids, with a significant contribution of esterified fatty acids with elongated carbon chains and unsaturated lipids. The other factors while choosing solvent are that it should be as nonpolar as possible to minimize solute–solvent interactions; and it should not strongly absorb IR radiation. It’s based on principles of collaboration, unobstructed discovery, and, most importantly, scientific progression. It can be determined by characteristic peaks. By Khayelihle Ncama, Lembe S. Magwaza, Asanda Mditshwa and Samson Z. Tesfay, By Héctor Herrera Hernández, Adriana M. Ruiz Reynoso, Juan C. Trinidad González, Carlos O. González Morán, José G. Miranda Hernández, Araceli Mandujano Ruiz, Jorge Morales Hernández and Ricardo Orozco Cruz. How? El-Menshawe et al. General band assignment of the FTIR spectrum of an adipose tissue. PCA method was applied to spectral data. The results of this study suggested that membrane order is not responsible for the lower rate of lipolysis in animals fed coconut oil when both variables are measured at 37°C. IR spectroscopy presents the great power in the biomedical research area due to mentioned advantages above, high sensitivity and ease application, Furthermore, IR spectroscopy is concerned as a high throughput technique that is very practical to quantify the alteration of structure, function, composition and distribution, of biologically relevant components in samples. Nonalcoholic fatty liver disease (NAFLD) is a frequent lesion associated with obesity, diabetes, and the metabolic syndrome. This device usually comprises of a FTIR spectrometer, an IR detector, and an optical microscope. Each PC describes the spectral variability among samples in decreasing order. Spectroscopy is the measurement and interpretation of electromagnetic radiation absorbed or emitted when the molecules or atoms or ions of a sample moves from one energy state to another energy state. Lower symmetry of Complexes:Due to formation of ligand & polynuclear complexes.3. FTIR spectroscopy and synchrotron X-ray fluorescence (SRXRF) microprobe techniques show that brain areas implicated appetite control, upon experimental treatment by either anodal-type tDCS (atDCS) or cathodal-type tDCS (ctDCS). The mid-IR spectra were acquired from serum, and then analyzed to develop a predictive model of the steatosis level. Entire IR region is divided into group frequency region and fingerprint region. The relationship between the spectroscopy-predicted and observed levels of steatosis, expressed as percentages of the liver biopsy area, was not linear. Interest in the application of near infrared spectroscopy to microbiological research and analysis has grown in recent times. In the literature, visceral adipose tissue has been implicated as a major risk factor for insulin resistance, type 2 diabetes [48, 58], cardiovascular disease [59], stroke [60], and metabolic syndrome [61]. Publishing on IntechOpen allows authors to earn citations and find new collaborators, meaning more people see your work not only from your own field of study, but from other related fields too. In the case of nutrition overload, function of ER is impaired, protein folding is disturbed, ER stress develops and activates a signaling network called the unfolded protein response (UPR) to restore ER homeostasis [64, 65]. Among the different methods used in cluster analysis, generally Ward’s algorithm together with Euclidian distances is used to construct the dendrograms, which gives one of the best predictions [45]. Applications. The global Terahertz and Far-infrared Spectroscopy market is expected to grow at a significant pace, reports Market Research Port. On the other hand, semi-permanent cells are removable so that the windows can easily be cleaned. [72] investigated the biochemical changes caused by cold exposure using FTIR imaging technique in the brown and subcutaneous white adipose tissues (BAT and s-WAT) of 6-week-old C57BL6 mice exposed to different temperatures for 10 days. The discriminatory power of these techniques in diagnosis of obesity will be discussed. If absorbed energy is plotted as a function of wavenumber, an IR spectrum is observed. Help us write another book on this subject and reach those readers. Rsad2, which may modulate lipid droplet contents and lipid biosynthesis, and Colec11, which may play a role in apoptotic cell clearance and maintenance of adipose tissue were suggested as potential quantitative trait candidate genes. The most commonly used alkali halide is KBr, which is completely transparent in the MID-IR region [18]. A representative baseline corrected normalized FTIR spectrum of a human adipose tissue in the 4000–750 cm−1 region. The degree of unsaturation was obtained from the ratio of the integrated area of unsaturated lipids (2992–3020 cm−1) to the integrated area of saturated lipids (2830–2980 cm−1), showed stepwise decreases going from colder-exposed to warmer-exposed BAT. IR spectra of two enatiomeric compound are identical. Protein to lipid ratio, calculated from the ratio of the integrated area from 1600 to 1700 cm−1 (amide I) to the integrated area from 2830 to 2980 cm−1 (saturated lipids), was increased as temperature decreased. Finally, tissue samples are thaw-mounted on IR-transparent CaF2 or BaF2 windows for IR mapping and data processing [36]. The wavelength of absorbed light is specific to the material taken. For example, the mechanism of the protective role of fatty acids, the effect of macrophage localization and origin to induce inflammation in adipose tissue and ER stress induced response of different organs such as liver, adipose tissue, anti-obesity effect of diets, therapeutic effect of drug, structural characterization of obese human membranes, tissues and organs are still not exactly known and further researches are required. It is a well-known technique for reducing the dimensionality of multivariate data while preserving most of the variance [43]. Drying process is applied to remove the bulk water from the samples. According to Beer–Lambert law, the signal intensity or more accurately the area under the bands gives concentration information. Furthermore, PCA is capable to obtain loadings plots to identify the main contributory variables (i.e., wavenumbers) that determine the discriminating wavenumbers throughout the IR spectrum. A recent article discussed the potential of ATR-FTIR spectroscopy to monitor obesity from the triglyceride spectral band located around 1730 cm−1 [43]. Both genetic and environmental factors contribute to the development of metabolic complications, which result in a significant health and economic burden. The epididymal adipose tissue, liver, and muscle of 29 BXD recombinant inbred mouse strains fed with high fat diet were used to analyze the role of white adipose tissue as a mediator of inflammation. Before producing an IR sample in solution, a suitable solvent must be chosen. It should be performed before any scaling or other preprocessing steps, but after baseline correction. This technique can reduce a large scale of spectra to a point in a space by using linear transformation. [22]. The RS spectra showed an absorption band at 3416.50 cm−1, (O-H stretching) and 2926.85 cm−1 by C-H stretching vibration. Rao, Chemical Applications of Infrared Spectroscopy, Academic Press, New York, 1963. [80] used FTIR microspectroscopy coupled with chemometrics to monitor and discriminate biomolecular changes due to the anti-adipogenesis effect of baicalein on adipogenesis in 3 T3-L1 cells. The rats were fed with diets containing menhaden oil (MO) or coconut oil (CO) for 4 weeks. TFA were measured by FTIR-ATR spectroscopy. SCAT possesses higher concentrations of leptin and adiponectin. If the crystal size of the sample is too large, excessive scattering of radiation results, especially at high wavenumbers (this is known as the Christiansen effect) [25]. HeadquartersIntechOpen Limited5 Princes Gate Court,London, SW7 2QJ,UNITED KINGDOM. Spectral analysis. Therefore, adipose tissues draw attraction in obesity research. IR spectroscopy is a technique based on the study of absorption of IR radiation, which causes transition between vibrational energy states in the molecule. The shift in the position of the C=O stretching and the PO2− anti-symmetric double stretching bands gives information about hydration status of these functional groups [20, 24]. If any additional peaks are observed in the IR spectrum, then it is due to impurities present in the compound. White adipose tissue has been organized in different anatomical location as visceral white adipose tissue (VAT) and subcutaneous white adipose tissue (SCAT). Spectroscopy is based on the interactions between matter (sample analyzed) and energy from the portion of electromagnetic spectrum. In conclusion, the VAT and especially, the SCAT samples can be easily examined by ATR-FTIR spectroscopy coupled with chemometrics in human studies and this combined technique will shed light on the internal diagnosis of obesity in medical research [43]. An IR microscope has reflective optics that allows the microscope to cover the entire spectral range of IR light. (Click on Subscription link in your inbox), Privacy Policy | Disclaimer | Terms of Use | Advertise | Sitemap | Send Feedback, RECEIVED AWARD AS BEST PHARMA CAREER PORTAL AT ISFCP, Copyright © 2008-2020, PharmaTutor Edu Labs, Entire IR region is divided into group frequency region and fingerprint region. Transmission spectroscopy is the oldest and most straightforward method that based upon the absorption of IR radiation at specific wavelengths as it passes through a sample, which can be in liquid and solid samples [17]. The large number of wavelengths emitted by these systems makes it possible to investigate their structures in detail, including the electron configurations of ground and various excited states. Other techniques include skinfold thickness, dual energy X-ray absorptiometry, bioelectrical impedance, plethysmography, underwater weighing, computed tomography, and near-IR interactance. IR doesn't alter the evidence since very small amounts of energy are applied. The ratio of the sample to alkali halide is important; generally, sample to halide ratio is chosen as 1:100. Near-infrared (NIR) spectroscopy is a method commonly used to analyze organic molecules in the production of pharmaceutics and food. The prevalence of obesity has increased drastically in recent decades and reached global epidemic dimensions [3, 4]. Infrared spectroscopy is widely used in industry as well as in research. In membrane studies, since the OH stretching bands (3400–3200 cm−1 and 1800–1500 cm−1) due to the buffer, these bands overlap with the bands of interest. [78] evaluated nano lipo-vesicles phytosomal thermogel of Soybean [Glycine max (L.) Merrill], for its anti-obesity action on body weight gain, adipose tissue size, and lipid profile data by FTIR spectroscopy. Includes instrumental and sampling techniques Covers biological and industrial applications Includes suitable questions and problems in each chapter … Multiple methods exist to perform baseline correction. Smoothing is used to reduce noise in data. In order to achieve this, the gonadal (visceral) and inguinal (subcutaneous) adipose tissues of male BFMI lines, which are spontaneously obese were studied. In recent years, near-infrared spectroscopy (NIR) has been widely used for the analysis of characteristics with rapid analysis speed and low cost [,,, ]. Brown adipose tissue (BAT) is highly specialized in thermogenesis and maintaining body temperature [46]. Since each molecule will have its own unique vibrational characteristics, each molecule possesses a unique IR spectrum. This chapter is distributed under the terms of the Creative Commons Attribution 3.0 License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Promising new experimental tools and models will help for elucidating remaining questions related to obesity and may be critical for the development of the new therapeutic strategies. Applications of IR spectroscopic techniques allow identifying molecular changes due to obesity, to understand the molecular mechanism of the disease, to identify specific spectral biomarkers that can be used in diagnosis. As seen from Figure 3, successful discrimination of the obese, obesity-related insulin resistant and control groups was achieved with high sensitivity and specificity. Some of the major applications of IR spectroscopy are as follows: 1. Suitable questions and problems are included in each chapter to assist in the analysis and interpretation of representative infrared spectra. Spectrum as a reflection of molecular structure of sample includes series of peaks/bands with unique characteristic properties such as band position, band width, and band intensity/area. A drop of liquid is sandwiched, using suitable spacer, between two IR windows that are then mounted in a cell holder. The results also showed that SCAT was more prone to obesity-induced structural changes than VAT. The most dramatic lipid-related changes were found for γas(CH2) at 2930 cm−1, whereas the protein secondary changes occurred at the amide I band, for α–helix and β-sheet located at 1660 and 1630 cm−1, respectively. (Adapted from [34], with permission from Royal Society of Chemistry). For COS analysis, in IR spectroscopy, the absorption peak at 3416.33 cm−1 belonged to O-H and N-H stretching vibrations, 2922.80 cm−1 corresponding to a C-H stretching vibration, and 1566.70 cm−1 originated from -NH2 absorption peak were used. IR microscopy, also called as IR microspectroscopy, is a type of light microscopy. Interferometers made far-IR spectroscopy possible, and enabled observation of lattice vibrations of crystals, low-frequency skeletal motions of organics and the stretching modes of heavy atoms. In vector normalization, the sum of all intensity values squared of normalized mean-centered spectrum is equal to 1. Animals subjected to enriched diets were obese. Such materials include Diamond, zinc selenide (ZnSe), germanium (Ge), silicon (Si), and thallium/iodide. Spectroscopy, study of the absorption and emission of light and other radiation by matter, as related to the dependence of these processes on the wavelength of the radiation. This inflammatory state is associated with increased accumulation of macrophages in adipose tissues along with the production of inflammatory cytokines and their secretion into the circulation (e.g., adiponectin, leptin, resistin, IL6, IL10, TNFα, macrophage migration inhibitory factor [51], and components of the renin-angiotensin system [52]). Both, atDCS and ctDCS produced significant molecular changes involving qualitative and structural properties of lipids, whereas atDCS induced more significant effect on protein secondary structure in all the brain areas investigated [75]. In future, these novel approaches will shed light on the internal diagnosis of obesity in clinical application. If quantitative analysis of a sample is required, it is necessary to use a cell of known path length [20, 21]. PCA analysis successfully operated to groups. Hierarchical clustering of control, obese and obesity related insulin resistant groups in SCAT (A) and VAT (B) in the 1770–1720 cm−1 spectral region. essentially a graph plotted with the infrared light absorbed on the Y-axis The data suggest that mid-IR spectroscopy combined with statistical analysis allows identifying serum mid-IR signatures that reflect the liver status during NAFLD [73]. The IR spectroscopy results of the animal studies on adipose tissues can be transferred to medical research to be used in the diagnosis of obesity. Recent studies pointed out the importance of adipose tissue in diagnosis and treatment of obesity and obesity related diseases. The waist circumference (WC) is also used to monitor central obesity and measured at a level midway between the lowest rib and the iliac crest. Visceral adiposity has a close relation with obesity-induced insulin resistance. Because they are supervised methods, there is a need for cross-validation and independent validation dataset. VAT has higher amount of plasminogen activator inhibitor-1 (PAI-1), IL6 and higher expression of glucocorticoid, androgen, AT1 and beta-3 adrenergic receptor than in the subcutaneous tissue. PC1 versus PC2 scores plot of the second derivative vector normalized spectra in the same range of SCAT (C) and VAT (D). Stability of body fat is key point to maintain metabolic homeostasis. Biological samples contain biochemical substances such as lipids, proteins, carbohydrates, proteins, and nucleic acids, and these biomolecules have their unique vibrational fingerprints. The authors report no financial conflicts of interest. Identification of functional group and structure elucidation. Protein in solution and membrane studies are only performed using this method [19]. The KBr pellet technique has been extensively used to study a variety of biological systems in dry stated [31, 32]. Control group (black), obese group (BFMI 852–856) (red), obesity related insulin resistant group (BFMI 860–861) (blue). TFA content in all adipose tissues analyzed was higher than reported in other countries. Enter your mobile number or email address below and we'll send you a link to download the free Kindle App. The material must be transparent to the incident IR radiation and normally alkali halides are used in transmission methods [20, 22, 23]. Instrumentation and sampling techniques. In the study, 75 mice were subjected to a control, high-fat or high-fat-high carbohydrate diets. Some popular sampling techniques and accessories will be discussed below. UV Spectroscopy- Principle, Instrumentation, Applications. The current study clearly revealed the power of FTIR microspectroscopy in the precise determination of obesity-induced structural and functional changes in inguinal and gonadal adipose tissue of mice lines [34]. PCA can be used to define groups based on spectral similarity/variance as classification method. The wavelength range for the three spectra is 0-400, 400-700, and above.