Propitious catalytic response of immobilized α-amylase from G. thermoleovorans in modified APTES-Fe3O4 NPs for industrial bio-processing.

Challenges in enzyme and product recovery are currently intriguing in modern biotechnology. Coping enzyme stability, shelf life and efficiency, nanomaterials-based immobilization were epitomized of industrial practice. Herein, a α-amylase from Geobacillus thermoleovorans was purified and bound effectively on to a modified 3-Aminopropyltriethoxysilane (APTES)-Fe3O4 nanoparticle. It was revealed that the carrier-bound enzyme catalysis (pH 8 and 60 °C) was significant in contrast to the free enzyme (pH 7.5 and 55 °C). Furthermore, Zn2+ and Cu2+ were shown to cause inhibitory effects in both enzyme states. Unlike chloroform, toluene, benzene, and butanol, minimal effects were observed with ethanol, acetone, and hexane. The bound enzyme retained 27.4 % of its initial activity after being stored for 36 days. In addition, the reusability of the bound enzyme showed a gradual decline in activity after the first cycle; however, after 13 cycles, its residual activity at 53 % was observed. These data proved significant enough to use this enzyme for industrial starch and analogous substrate bio-processing.

Fabrication of a sensing platform for identification of tumor necrosis factor-alpha: a biomarker for neonatal sepsis.

Neonatal sepsis is a prime cause of neonatal deaths across the globe. Presently, various medical tests and biodevices are available in neonatal care. These diagnosis platforms possess several limitations such as being highly expensive, time-consuming, or requiring skilled professionals for operation. These limitations can be overcome through biosensor development. This work discusses the assembling of an electrochemical sensing platform that is designed to detect the level of tumor necrosis factor-alpha (TNF-α). The sensing platform was moderated with nanomaterials molybdenum disulfide nanosheets (MoS2NSs) and silicon dioxide-modified iron oxide nanoparticles (Fe3O4@SiO2NPs). The integration of nanomaterials helps in accomplishing the improved characteristics of the biosensor in terms of conductivity, selectivity, and sensitivity. Further, the molecularly imprinted polymer (MIP) approach was incorporated for sensing the presence of TNF-α on the surface of the working electrode. The electrochemical response of the electrode was recorded at different conditions. A broad concentration range was selected to optimize the biosensor from 0.01 pM to 100 nM. The sensitivity of the biosensor was higher and it exhibits a lower detection limit (0.01 pM).

Role of C/N ratio on microalgae growth in mixotrophy and incorporation of titanium nanoparticles for cell flocculation and lipid enhancement in economical biodiesel application.

Present study aimed to evaluate the influence of carbon/nitrogen ratio (C/N) on mixotrophic growth of microalgae and role of nanomaterial in cell recovery and lipid improvement. In this study, three microalgae species were isolated, screened from local freshwater body for lipid assimilation. The microalgae were identified as Chlorococcum sp., Scenedesmus sp., and Euglena sp. Mixotrophic cultivation of each microalgae strain using various organic carbon sources was preferred in contrast with photoautotrophic mode. Sucrose represented as the preeminent source for enhancing the microalgae biomass of 3.5 g/L and lipid content of 58.35%, which was a significant improvement as compared to control. Later, response surface methodology-central composite design (RSM-CCD), tool was employed to optimize the C/N ratio and demonstrated the maximum biomass production of 5.02 g/L along with the increased lipid content of 60.34%. Ti nanoparticles (Ti nps) were added to the culture for lipid enhancement in the stationary phase and biomass removal was performed by nanoparticle (np)-mediated flocculation technique. Optimized concentration of 15 ppm Ti nps determined the cell harvesting efficacy of 82.46% during 45 min of sedimentation time and 1.23-fold lipid enhancement was reported. Extracted lipid was converted to fatty acid methyl esters (FAME) by the process of transesterification and analyzed by gas chromatography-mass spectrometry (GC-MS). Characterization of FAME revealed the presence of 56.31% of saturated fatty acid (SFA) and 29.06% unsaturated fatty acids (UFA) that could be processed towards sustainable biodiesel production. Hence, our results suggested that integration of mixotrophic cultivation and Ti nps emerged as a new cost-effective approach for biomass and lipid enhancement in microalgae Chlorococcum sp.

Juglans regia and Ribes nigrum as potential nutraceuticals: Source of thermostable superoxide dismutase enzyme.

In the present study, superoxide dismutase (SOD) extracted from dry fruits; Juglans regia (Walnut; W) and Ribes nigrum (Munakka; M) was partially purified into 0%-40% and 40%-80% fractions based on ammonium sulfate saturation levels. The partially purified fractions (0%-40%) exhibited purification level of 3.09- (W) and 3.22- (M) fold with specific activity 79.32 Umg-1 (W) and 125.23 Umg-1 (M). SOD from both the sources was found to be thermally stable, that is, 80°C (W) and 70°C (M). Kinetic studies showed Km values to be 3.33 mM (W) and 2.86 mM (M), whereas the activation energy (Ea ) calculated as 24.52 KJ mol-1 (W) and 26.25 KJ mol-1 (M). Na+ , Mn2+ , and Ba2+ ions acted as potential inhibitors, whereas Fe2+ stimulated SOD from both the sources. Among these metal ions, Na+ exhibited uncompetitive inhibition in both cases; with Ki values of 0.7 mM (W) and 0.9 mM (M), suggesting the more prominent binding affinity and effectiveness. PRACTICAL APPLICATIONS: Awareness need to be created among people for multifactorial health benefits of nutraceuticals in day-to-day life. Nutritional consumption from fruits, nuts, and vegetables safeguard against various maladies like cardiovascular diseases, diabetes, and cancers. Superoxide dismutase (EC 1.15.1.1) is a standout among the most critical metal-containing enzymes that act as a main line of defense against oxidative stress. Antioxidant-based drugs and formulations have been developed in the recent years and research is emphasized on its impact on oxidative stress levels. In this study, Juglans regia (W) and Ribes nigrum (M) were found to have thermostable SOD enzyme with excellent antioxidant properties. Thermal stability of an enzyme improves its significance making it industry friendly with therapeutically vital products, alongside their utilization as supplement in numerous therapeutic formulations.

Spectroscopic determination of intracellular quercetin uptake using erythrocyte model and its implications in human aging.

The present study was carried out to detect intracellular quercetin uptake by RBCs during human aging. The study was carried out on 95 normal healthy subjects of both the sexes. Intracellular quercetin uptake was estimated by performing ethyl acetate extraction. A significant (p < 0.001) decline in intracellular quercetin uptake by human RBCs was observed in elderly as compared to young population, while plasma membrane redox system (PMRS) activity was significantly decreasing as a function of human age. To the best of our knowledge, we are the first to present quercetin uptake by erythrocytes during aging in humans with this study. It is hypothesized that intracellular uptake of quercetin may serve as an intracellular electron donor for plasma membrane redox system in red blood cells during cellular aging which plays an important role in extracellular dehydroascorbate reduction and ascorbate recycling.

Prospects of electrochemical immunosensors for early diagnosis of preeclampsia.

Preeclampsia is a vascular multisystem disorder that accounts for varying degree of morbidity and mortality of mother and the fetus. This can be significantly averted if diagnosed at an early (18-20 weeks) stage of gestation, as there is no known way to prevent preeclampsia. In spite of extensive work on biomarker discovery, the existing method for its detection is mostly based on colorimetric immunoassays whose sensitivity is ranging in nanomolar range. Further, it has also been observed that change in the expression of a single biomarker is not sufficient to diagnose this condition. So, for early diagnosis (by 18-20 weeks), an immuno-diagnostic platform with detection limits in picomolar range and beyond along with the ability to do simultaneous detection of multiple analyte would be of great importance. A nano-immunosensors with an electrochemical readout system can be a potential alternative that promises for the ultrasensitive detection of analyte with high specificity as well as suitability for on-site analysis. Coupling the lateral flow technology with immunosensors would make it feasible to detect more than one biomarker simultaneously on a microchip. This review intends to summarize the potential preeclampsia biomarkers, limitations of existing diagnostic methods along with the recent advancements, and prospects to develop electrochemical immunosensors for early clinical diagnosis.

Quercetin-modulated erythrocyte membrane sodium-hydrogen exchanger during human aging: correlation with ATPase's.

CONTENT: Quercetin uptake by erythrocytes is rapid. The sodium-hydrogen exchanger (NHE) is a secondary active transporter, regulating intracellular pH, Na(+) concentration and cell volume. OBJECTIVE: The aim of present study was to investigate NHE as a function of human age and effect of quercetin on its activity. The NHE activity was correlated with erythrocytes ATPases. MATERIALS AND METHODS: We analyzed normal, healthy subjects of both sexes (20-82 years). NHE activity was estimated in terms of amiloride-sensitive H+-efflux from acid-loaded cells. RESULTS: A significant age-dependent increase in NHE activity was observed during aging in humans. Concentration (10(-3 )M to 10(-8 )M)-dependent in vitro treatment with quercetin causes inhibition of NHE activity. The Na(+)/K(+) -ATPase (r = 0.8882) and Ca(2+)-ATPase (r = 0.9540) activities positively correlated with it. DISCUSSION AND CONCLUSION: The present data show an additional mechanism where dietary flavonoids may exerts beneficial effect during aging.

Age-dependent detection of erythrocytes glucose-6-phosphate dehydrogenase and its correlation with oxidative stress.

CONTEXT: Glucose-6-phosphate dehydrogenase (G6PD) is an important enzyme of hexose monophosphate shunt, involved in the biosynthesis of reduced nicotinamide adenine dinucleotide phosphate hydrogen (NADPH). OBJECTIVE: This study was designed to investigate age-dependent changes in human erythrocyte G6PD activity. The G6PD activity pattern was correlated with reduced glutathione (GSH) and total antioxidant potential in terms of FRAP (ferric reducing ability of plasma) value. MATERIALS AND METHODS: We analyzed normal, healthy subjects of both sexes between the ages of 20 and 80 years. G6PD activity was determined by Burties method. RESULTS: We observe a significant age-dependent decrease in G6PD activity (p < 0.0001). It was positively correlated with GSH (r = 0.5706) and total antioxidant potential (r = 0.7723) as a function of human age. DISCUSSION AND CONCLUSION: Our findings on erythrocyte G6PD and their correlation with GSH and FRAP provide evidence of a higher oxidative stress in old age population.

Biomarkers of oxidative stress in erythrocytes as a function of human age.

Despite more than 300 theories to explain the aging process, oxidative stress theory offers the best mechanism to explain aging and age related disorders. Several studies has shown the importance of oxidative stress during aging. PubMed, Science Direct and Springer online data bases are taken into consideration to write this mini-review. Human erythrocytes are most abundant and specialized cells in the body. Erythrocytes were extensively studied due to their metabolism and gas transport functions. Recent studies on erythrocytes have provided us detailed information of cell membrane and its structural organization that may help in studying the aging and age associated changes. The susceptibility of an organism is associated with the antioxidant potential of the body. Erythrocytes have potent antioxidant protection consisting of enzymatic and non-enzymatic pathways that counteract with reactive oxygen species, thus maintaining the redox regulation in the body. The non-enzymatic and enzymatic antioxidants and other biomarkers associated with erythrocyte membrane transport functions are the main content of this review. Biomarkers of oxidative stress in erythrocytes and its membrane were taken into the consideration during human aging that will be the main subject of this mini- review.

Influence of Dietary Capsaicin on Redox Status in Red Blood Cells During Human Aging.

PURPOSE: Capsaicin (8-methyl-N-vanillyl-6-nonenamide) is a major pungent compound found in hot peppers of the plant genus Capsicum. In vitro effects of dietary capsaicin on redox status in red blood cells during human aging have been explored. METHODS: Total antioxidant potential of capsaicin was evaluated using Ferric reducing ability of plasma (FRAP) assay. GSH was measured as per standard protocol. The in vitro effect of capsaicin was evaluated by incubation of the cells in the assay medium with 10(-5)M capsaicin (final concentration) for 60 min at 37°C. RESULTS: Treatment with capsaicin (10(-5)M) caused a significant (p < 0.01) increase in GSH level in all age groups. Reduced glutathione (GSH) / Oxidized glutathione (GSSG) ratio measures the redox status of the red blood cell. Significant increase in GSH level due to capsaicin, shift the GSH/GSSG ratio, thus alters the redox status of the cell. CONCLUSION: The results conclusively prove the efficacy of the antioxidant property of capsaicin and its role in modulating the redox status of red blood cells. This evidence suggests that dietary factors that act as antioxidants to increase GSH level may contribute to a protective effect against age related diseases. This antioxidant effect may, in part, explain the high consumption of capsicum in certain regions of the world.

Epigallocatechin-3-Gallate Protects Erythrocyte Ca(2+)-ATPase and Na(+)/K(+)-ATPase Against Oxidative Induced Damage During Aging in Humans.

PURPOSE: The main purpose of this study was to investigate the protective role of epigallocatechin-3-gallate on tertiary butyl hydroperoxide induced oxidative damage in erythrocyte during aging in humans. METHODS: Human erythrocyte membrane bound Ca(2+)-ATPase and Na(+)/K(+)-ATPase activities were determined as a function of human age. Protective role of epigallocatechin-3-gallate was evaluated by in vitro experiments by adding epigallocatechin-3-gallate in concentration dependent manner (final concentration range 10(-7)M to 10(-4)M) to the enzyme assay medium. Oxidative stress was induced in vitro by incubating washed erythrocyte ghosts with tertiary butyl hydroperoxide (10(-5) M final concentration). RESULTS: We have reported concentration dependent effect of epigallocatechin-3-gallate on tertiary butyl hydroperoxide induced damage on activities of Ca(2+)-ATPase and Na(+)/K(+)-ATPase during aging in humans. We have detected a significant (p < 0.001) decreased activity of Ca(2+)-ATPase and Na(+)/K(+) -ATPase as a function of human age. Epigallocatechin-3-gallate protected ATPases against tertiary butyl hydroperoxide induced damage in concentration dependent manner during aging in humans. CONCLUSION: Epigallocatechin-3-gallate is a powerful antioxidant that is capable of protecting erythrocyte Ca(2+)-ATPase and Na(+)/K(+) -ATPase against oxidative stress during aging in humans. We may propose hypothesis that a high intake of catechin rich diet may provide some protection against development of aging and age related diseases.

Prospects and advancements in C-reactive protein detection.

C-reactive protein (CRP) is one of the earliest proteins that appear in the blood circulation in most systemic inflammatory conditions and this is the reason for its significance, even after identification of many organ specific inflammatory markers which appear relatively late during the course of disease. Earlier methods of CRP detection were based on the classical methods of antigen-antibody interaction through precipitation and agglutination reactions. Later on, CRP based enzymatic assays came into the picture which were further modified by integration of an antigen-antibody detection system with surface plasma spectroscopy. Then came the time for the development of electrochemical biosensors where nanomaterials were used to make a highly sensitive and portable detection system based on silicon nanowire, metal-oxide-semiconductor field-effect transistor/bipolar junction transistor, ZnS nanoparticle, aptamer, field emission transmitter, vertical flow immunoassay etc. This editorial attempts to summarize developments in the field of CRP detection, with a special emphasis on biosensor technology. This would help in translating the latest development in CRP detection in the clinical diagnosis of inflammatory conditions at an early onset of the diseases.

L-cysteine efflux in erythrocytes as a function of human age: correlation with reduced glutathione and total anti-oxidant potential.

Thiol compounds such as cysteine (Cys) and reduced glutathione (GSH) play an important role in human aging and age-related diseases. In erythrocytes, GSH is synthesized by glutamic acid, cysteine, and glycine, but the rate of GSH synthesis is determined only by the availability of L-cysteine. Cysteine supplementation has been shown to ameliorate several parameters that are known to degenerate during human aging. We have studied L-cysteine efflux in vitro in human erythrocytes as a function of age by suspending cells in solution containing 10 mM L-cysteine for uptake; later cells were re-suspended in phosphate-buffered saline (PBS)-glucose to allow efflux. Change in the free sulfhydryl (-SH) concentration was then measured to calculate the rate of efflux. The GSH/oxidized glutathione (GSSG) ratio was taken as a control to study the oxidation/reduction state of the erythrocyte. The total anti-oxidant potential of plasma was measured in terms of ferric reducing ability of plasma (FRAP) values. We have shown a significant (p<0.0001) decline in the efflux of L-cysteine in erythrocytes during human aging, and the GSH/GSSG ratio decreases as a function of human age. The decline in L-cysteine efflux during aging correlates with the decrease in GSH and the FRAP value. This finding may help to explain the shift in the redox status and low GSH concentration that might determine the rate of L-cysteine efflux observed in erythrocytes and an important factor in the development of oxidative stress in erythrocytes during aging.

Age-associated changes in erythrocyte glutathione peroxidase activity: correlation with total antioxidant potential.

Oxidative stress is believed to play a central role in aging and age-associated diseases. It leads to oxidative changes in human red blood cells (RBCs) in vivo and in vitro. In this study, we evaluated the oxidative damage to the erythrocytes during aging in the humans using RBC as a model, by measuring the cytosolic antioxidant enzyme glutathione peroxidase (GPx) activity. GPx activity was found to be significantly decreased as a function of human age and positively correlated with total antioxidant capacity, while negatively correlated with SOD activity. Thus, results of the present study showed involvement of oxidative stress as one of the risk factors, which can initiate and/or promote human aging.