In vitro antioksidacijska, citotoksična i antidijabetička aktivnost hidrolizata proteina iz Reevesove barske kornjače (Chinemys reevesii)

Research background. Cardiovascular diseases and diabetes are the biggest causes of death globally. Bioactive peptides derived from many food proteins using enzymatic proteolysis and food processing have a positive impact on the prevention of these diseases. The bioactivity of Chinese pond turtle muscle proteins and their enzymatic hydrolysates has not received much attention, thus this study aims to investigate their antioxidant, antidiabetic and cytotoxic activities. Experimental approach. Chinese pond turtle muscles were hydrolysed using four proteolytic enzymes (Alcalase, Flavourzyme, trypsin and bromelain) and the degrees of hydrolysis were measured. High-performance liquid chromatography (HPLC) was conducted to explore the amino acid profiles and molecular mass distribution of the hydrolysates. The antioxidant activities were evaluated using various in vitro tests, including 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), hydroxyl radical scavenging activity, reducing capacity, chelating Fe2+ and lipid peroxide inhibition activity. Antidiabetic activity was evaluated using α-amylase inhibition and α-glucosidase inhibition assays. Besides, cytotoxic effect of hydrolysates on human colon cancer (HT-29) cells was assessed. Results and conclusions. The amino acid composition of the hydrolysates revealed higher mass fractions of glutamic, aspartic, lysine, hydroxyproline and hydrophobic amino acids. Significantly highest inhibition of lipid peroxidation was achieved when hydrolysate obtained with Alcalase was used. Protein hydrolysate produced with Flavourzyme had the highest radical scavenging activity measured by DPPH (68.32%), ABTS (74.12%) and FRAP (A700 nm=0.300) assays, α-glucosidase (61.80%) inhibition and cytotoxic effect (82.26%) on HT-29 cell line at 550 µg/mL. Hydrolysates obtained with trypsin and bromelain had significantly highest (p<0.05) hydroxyl radical scavenging (92.70%) and Fe2+ metal chelating (63.29%) activities, respectively. The highest α-amylase (76.89%) inhibition was recorded when using hydrolysates obtained with bromelain and Flavourzyme. Novelty and scientific contribution. Enzymatic hydrolysates of Chinese pond turtle muscle protein had high antioxidant, cytotoxic and antidiabetic activities. The findings of this study indicated that the bioactive hydrolysates or peptides from Chinese pond turtle muscle protein can be potential ingredients in pharmaceuticals and functional food formulations.Pozadina istraživanja. Kardiovaskularne bolesti i dijabetes najčešći su uzroci smrti na svijetu. Bioaktivni peptidi dobiveni proteolizom i preradom hrane imaju pozitivan učinak na prevenciju tih bolesti. Biološka aktivnost proteina iz mišića Reevesove barske kornjače i njihovih hidrolizata nije dovoljno istražena, stoga je svrha ovoga rada bila ispitati njihovu antioksidacijsku, antidijabetičku i citotoksičnu aktivnost. Eksperimentalni pristup. Mišići Reevesove barske kornjače hidrolizirani su pomoću proteolitičkih enzima (Alcalase, Flavourzyme, tripsin i bromelain), te su mjereni stupnjevi hidrolize proteina. Aminokiselinski sastav i distribucija molekularne mase hidrolizata ispitani su pomoću visokodjelotvorne tekućinske kromatografije. Antioksidacijska aktivnost određena je različitim testovima in vitro, uključujući sposobnost uklanjanja 1,1-difenil-2-pikrilhidrazila (DPPH), 2,2’-azino-bis(3-etilbenzotiazolin-6-sumporne kiseline) (ABTS) i hidroksil radikala, keliranja Fe2+ i inhibicije lipidne peroksidacije. Antidijabetička aktivnost ispitana je testovima inhibicije α-amilaze i α-glukozidaze. Osim toga, analiziran je citotoksični učinak hidrolizata na stanice tumora debelog crijeva (HT-29). Rezultati i zaključci. Analizom aminokiselinskog sastava hidrolizata pronađeni su veći maseni udjeli glutaminske i asparaginske kiseline, lizina, hidroksiprolina te hidrofobnih aminokiselina od onih u nehidroliziranim proteinima. Hidrolizat proteina dobiven pomoću proteolitičkog enzima Alcalase bitno je inhibirao peroksidaciju lipida. Pri koncentraciji od 550 µg/mL, hidrolizat proteina dobiven pomoću enzima Flavourzyme imao je najveću sposobnost uklanjanja slobodnih radikala mjerenu pomoću DPPH (68,32 %), ABTS (74,12 %) i FRAP (A700 nm=0,300) metoda, inhibicije α-glukozidaze (61,80 %) te najveći citotoksični učinak na stanične linije HT-29 (82.26 %). Hidrolizat proteina dobiven pomoću tripsina imao je znatnu (p<0,05) aktivnost uklanjanja hidroksilnih radikala (92,70 %), a onaj dobiven pomoću bromelaina najveću aktivnost keliranja Fe2+ (63,29 %). Najveća inhibicija α-amilaze postignuta je pomoću hidrolizata proteina dobivenih djelovanjem bromelaina i enzima Flavourzyme. Novina i znanstveni doprinos. Hidrolizati proteina mišića Reevesove barske kornjače dobiveni enzimskom hidrolizom imali su veliku antioksidacijsku, citotoksičnu i antidijabetičku aktivnost. Rezultati istraživanja pokazuju da se ti hidrolizati ili peptidi zbog svojih bioaktivnih svojstava mogu upotrijebiti kao sastojak u farmaceutskim i funkcionalnim prehrambenim proizvodima

Robust Fault-Tolerant Tracking Control for Nonlinear Networked Control System: Asynchronous Switched Polytopic Approach

This paper is concerned with the robust fault-tolerant tracking control problem for networked control system (NCS). Firstly, considering the locally overlapped switching law widely existed in engineering applications, the NCS is modeled as a locally overlapped switched polytopic system to reduce designing conservatism and solving complexity. Then, switched parameter dependent fault-tolerant tracking controllers are constructed to deal with the asynchronous switching phenomenon caused by the updating delays of the switching signals and weighted coefficients. Additionally, the global uniform asymptotic stability in the mean (GUAS-M) and desired weighted l2 performance are guaranteed by combining the switched parameter dependent Lyapunov functional method with the average dwell time (ADT) method, and the feasible conditions for the fault-tolerant tracking controllers are obtained in the form of linear matrix inequalities (LMIs). Finally, the performance of the proposed approach is verified on a highly maneuverable technology (HiMAT) vehicle’s tracking control problem. Simulation results show the effectiveness of the proposed method

Mechanistic Insights Into the Interaction Between Transcription Factors and Epigenetic Modifications and the Contribution to the Development of Obesity

Objective: The development of obesity is inseparable from genetic and epigenetic factors, and transcription factors (TFs) play an essential role in these two mechanisms. This review analyzes the interaction of TFs with epigenetic modifications and the epigenetic mechanisms underlying peroxisome proliferator-activated receptor (PPAR)γ, an important transcription factor, in the development of obesity.Methods: We describe the relationship between TFs and different epigenetic modifications and illustrate the several mechanisms described. Next, we summarize the epigenetic mechanisms of PPARs, an important class of transcription factors involved in obesity, that induce obesity with different triggering factors. Finally, we discuss the mechanisms of epigenetic modification of PPAR-related ligands in lipid metabolism and propose future avenues of research.Results: TFs participate in epigenetic modifications in different forms, causing changes in gene expression. The interactions between the different epigenetic modifications and PPARs are important biological developments that affect fat tissue differentiation, lipogenesis, and lipid metabolism, thereby inducing or inhibiting the development of obesity. We then highlight the need for more research to understand the role of epigenetic modifications and PPARs.Conclusions: Epigenetic mechanisms involved in the regulation of PPARs may be excellent therapeutic targets for obesity treatment. However, there is a need for a deeper understanding of how PPARs and other obesity-related transcription factors interact with epigenetic modifications

High-pressure x-ray diffraction study of SrMoO4 and pressure-induced structural changes

SrMoO4 was studied under compression up to 25 GPa by angle-dispersive x-ray diffraction. A phase transition was observed from the scheelite-structured ambient phase to a monoclinic fergusonite phase at 12.2(9) GPa with cell parameters a = 5.265(9) A, b = 11.191(9) A, c = 5.195 (5) A, and beta = 90.9, Z = 4 at 13.1 GPa. There is no significant volume collapse at the phase transition. No additional phase transitions were observed and on release of pressure the initial phase is recovered, implying that the observed structural modifications are reversible. The reported transition appeared to be a ferroelastic second-order transformation producing a structure that is a monoclinic distortion of the low-pressure phase and was previously observed in compounds isostructural to SrMoO4. A possible mechanism for the transition is proposed and its character is discussed in terms of the present data and the Landau theory. Finally, the EOS is reported and the anisotropic compressibility of the studied crystal is discussed in terms of the compression of the Sr-O and Mo-O bonds.Comment: 36 pages, 9 figures, 1 tabl