Response surface methodology was used for process optimization to covalently immobilize xylanase on the surface of glutaraldehyde–alginate beads. The process, optimized with respect to minimum ...‘enzyme load’, had an efficiency of >91%. An increase in Km (from 0.9 to 1.49%), Vmax (from 7092 to 8000IU/ml), optimum pH (from 5 to 5.5) and temperature (from 40 to 45°C) was recorded after immobilization. An improvement in thermostability of immobilized xylanase, judged by increased half-lives and D-values, was also observed. Thermodynamically, the better stability of immobilized xylanase could be attributed to the increase in enthalpy (ΔH°) and free energy (ΔG°) change after covalent attachment. The enzyme could be reused 5 times while retaining >85% of its original activity. The method of immobilization can overcome the problem of reduced permeability of xylan, a high molecular weight substrate, to its enzyme which is conventionally entrapped within the alginate beads.
The effects of solid substrates, initial moisture content, moistening medium, temperature and incubation time on xylanase production by
Aspergillus niger DFR-5 was studied and the highest activity ...(2596
IU/g dry substrate (gds)) was achieved in medium that contained wheat bran (WB) and soybean cake (SBC) at a ratio of 70:30, was moistened to 70% with MSS-2 mineral salt solution, and incubated for 6
days at 40
°C. Water at 37
°C was suitable for efficient recovery of enzyme from moldy WB–SBC medium. The extraction parameters for xylanase were optimized with respect to minimum volume of extractant using a central composite rotatable design (CCRD). The maximum recovery of xylanase (4465
±
52
IU/gds) with 92.5% desirability was obtained employing water (10
ml/gds) as extractant at 200
rpm for 60
min. The result shows that an overall 5.4-fold increase in xylanase production was obtained in concentrated form by optimizing medium components and extraction conditions.
In this study, chlorogenic acid (CGA), a phenolic compound widely distributed in fruits and vegetables, was encapsulated into chitosan nanoparticles by ionic gelation method. The particles exhibited ...the size and zeta potential of 210 nm and 33 mV respectively. A regular, spherical shaped distribution of nanoparticles was observed through scanning electron microscopy (SEM) and the success of entrapment was confirmed by FTIR analysis. The encapsulation efficiency of CGA was at about 59% with the loading efficiency of 5.2%. In vitro ABTS assay indicated that the radical scavenging activity of CAG was retained in the nanostructure and further, the release kinetics study revealed the burst release of 69% CGA from nanoparticles at the end of 100th hours. Pharmacokinetic analysis in rats showed a lower level of Cmax, longer Tmax, longer MRT, larger AUC0–t and AUC0–∞ for the CGA nanoparticles compared to free CGA. Collectively, these results suggest that the synthesised nanoparticle with sustained release property can therefore ease the fortification of food-matrices targeted for health benefits through effective delivery of CGA in body.
Abstract Background Stevia rebaudiana Bertoni has been used for the treatment of diabetes in, for example, Brazil, although a positive effect on antidiabetic and its complications has not been ...unequivocally demonstrated. This herb also has numerous therapeutic properties which have been proven safe and effective over hundreds of years. Streptozotocin is a potential source of oxidative stress that induces genotoxicity. Objective We studied the effects of stevia leaves and its extracted polyphenols and fiber on streptozotocin induced diabetic rats. We hypothesize that supplementation of polyphenols extract from stevia to the diet causes a reduction in diabetes and its complications. Design/Methods Eighty Wistar rats were randomly divided into 8 groups; a standard control diet was supplemented with either stevia whole leaves powder (4.0%) or polyphenols or fiber extracted from stevia separately and fed for one month. Streptozotocin (60 mg/kg body weight, i.p) was injected to the diabetic groups on the 31st day. Several indices were analyzed to assess the modulation of the streptozotocin induced oxidative stress, toxicity and blood glucose levels by stevia. Results The results showed a reduction of blood glucose, ALT and AST, and increment of insulin level in the stevia whole leaves powder and extracted polyphenols fed rats compared to control diabetic group. Its feeding also reduced the MDA concentration in liver and improved its antioxidant status through antioxidant enzymes. Glucose tolerance and insulin sensitivity were improved by their feeding. Streptozotocin was also found to induce kidney damage as evidenced by decreased glomerular filtration rate; this change was however alleviated in the stevia leaves and extracted polyphenol fed groups. Conclusion The results suggested that stevia leaves do have a significant role in alleviating liver and kidney damage in the STZ-diabetic rats besides its hypoglycemic effect. It might be adequate to conclude that stevia leaves could protect rats against streptozotocin induced diabetes, reduce the risk of oxidative stress and ameliorate liver and kidney damage.
Motion sickness (MS) is the visceral discomfort caused due to contradicting visual and vestibular inputs to the brain leading to nausea and vomiting. Sensory conflict theory which proves histamine ...elevations as the primary reason for MS provides a path for an effective pharmaco-therapy. We aimed to evaluate the anti-MS effect of hesperidin (HSP) by modulating histamine and histamine receptor H1 (HRH1) expression. The inhibitory effect of HSP on histamine release was studied in KU812 cells treated with 10 µM calcium ionophore. The in vivo anti-MS effect of HSP was evaluated in Balb/c mice. Thirty six mice were divided into six groups namely, normal control (NC, no rotation), hesperidin at 80 mg/kg body weight control (HSP80, no rotation), motion sickness (MS, rotation induced), dimenhydrinate (Standard drug) at 20 mg/kg body weight + rotation (STD + MS), hesperidin at 40 mg/kg body weight + rotation (HSP40 + MS) and hesperidin at 80 mg/kg body weight + rotation (HSP80 + MS). Hypothalamus and brainstem samples were analysed for histamine levels and HRH1 expression by RT-PCR, Western blot and immunohistochemistry analysis. Calcium ionophore treated KU812 cells significantly increased histamine release when compared to control cells. Pre-treatment with HSP inhibited histamine, HRH1 mRNA and protein expression. Histamine, HRH1 mRNA and protein expression in hypothalamus and brainstem samples of MS group increased significantly when compared to the NC group. Pre-treatment with HSP significantly reduced histamine, HRH1 mRNA and protein expression. Thus, indicating that HSP has a potent anti- MS effect by decreasing the elevated levels of histamine, HRH1 mRNA and protein expression in hypothalamus and brainstem regions.
•Fumonisin b1 induce hepatotoxicity in mice and reduced the cell viability in HepG2 cells.•Fumonisin b1 disturb sphingolipid metabolism and elevates sphingosine and sphinganine.•Apocynin is NADPH ...oxidase inhibitor significantly protects the liver damage and showed maximum cell viability.•Apocynin strong antioxidant protects the fumonisin b1 induce oxidative stress and apoptosis via inhibiting NADPH oxidase enzyme.
Previous studies have shown that hepatotoxicity and NADPH oxidase mediated oxidative stress was activated by fumonisin 1 (Fb1) exposure, which is considered to be a critical event in the Fb1-induced toxic effect. However, the detailed mechanisms underlying Fb1-induced liver toxicity remain elusive. In this study, apocynin, a specific inhibitor for NADPH oxidase, was used to test suppression of ROS by inhibititing NADPH oxidase and it can protect against Fb1 induced hepatotoxicity in mice model and using HepG2 cell lines. In this context, the toxicity of Fb1 was examined in male albino mice. Apocynin with 25,50,100mg/kg b/wt was pretreated for 7 days oral administration. Fb1 2.25mg/kg b/wt was injected subcutaneously for 3 days. In mice model Fb1 injection induced oxidative stress by significant rise in serum marker enzymes and lipid peroxidation along with the reduction of antioxidant enzymes. Pretreatment of mice with different doses of apocynin (25,50,100mg/kg b/wt) significantly lowered AST, ALT and lipid peroxidation levels against Fb1 treated mice. Hepatic enzymes like SOD, CAT, GPx, GR, GSH were significantly increased by treatment with apocynin, against Fb1 treated mice. Fb1 perturbs sphingolipid metabolism by inhibiting ceramide synthase activity hence in the present study quantification of sphingosine and sphinganine quantified by LC MS analysis. In Fb1 injected mice samples the sphingoid bases elevated than normal pretreatment with apocynin reduced the sphingoid bases. The observed data demonstrates 50 % cell survival with 50 µM challenge for 24 h, which was restored to 90 % by pre-treatment with 100µM apocynin. It also decreased the lactate dehydrogenase leakage and preserved the cellular morphology. The DNA damage and nuclear morphology were assessed by comet assay and DAPI staining. Fb1 damaged DNA and nuclear morphology protected by apocynin pretreatment. The ultra-structural change induced by the Fb1 in cell lines, vacuolation was observed pre-treated cells with apocynin showed normal cell structure without vacuolation. On the Other hand, cell cycle distribution analysis showed cell cycle arrest at G0/G1 phase induced by Fb1 and its modulations was observed in apocynin pretreted cells. The protein expression CAT, GPx downregulated with Fb1 treatment and apoptotic markers caspase-3 and caspase-8 was upregulated. Pretretment with apocynin restored the antioxidant enzymes and overexpressed apocynin markers also altered. These findings suggest that apocynin ameliorates Fb1 induced hepatic damage via its antioxidant defence mechanism and might be used to treat oxidative stress mediated hepatic disorders.
Fumonisin b1 induced hepatoxicity and its inhibitory activity by apocynin and sphingolipid metabolism disturb by fumonisin b1 and its prevention by apocynin. Oxidative stress related enzyme NADPH oxidase induce ROS by fumonisin b1. The increased generation of ROS as well as a decrease in antioxidant status may induce lipid, protein and DNA oxidation, leading to toxicity and apoptosis via caspase 3 and caspase 8. Finally, apoptosis and oxidative stress these two events can cause hepatotoxicity which is inhibited by NADPH oxidase. Display omitted
Pelargonidin chloride (PC) is one of the major anthocyanin found in berries, radish and other natural foods. Many natural chemopreventive compounds have been shown to be potent inducers of phase II ...detoxification genes and its up-regulation is important for oxidative stress related disorders. In the present study, we investigated the effect of PC in ameliorating citrinin (CTN) induced cytotoxicity and oxidative stress. The cytotoxicity of CTN was evaluated by treating HepG2 (Human hepatocellular carcinoma) cells with CTN (0-150 μM) in a dose dependent manner for 24 h, and the IC
was determined to be 96.16 μM. CTN increased lactate dehydrogenase leakage (59%), elevated reactive oxygen species (2.5-fold), depolarized mitochondrial membrane potential as confirmed by JC-1 monomers and arrested cell cycle at G2/M phase. Further, apoptotic and necrotic analysis revealed significant changes followed by DNA damage. To overcome these toxicological effects, PC was pretreated for 2 h followed by CTN exposure for 24 h. Pretreatment with PC resulted in significant increase in cell viability (84.5%), restored membrane integrity, reactive oxygen species level were maintained and cell cycle phases were normal. PC significantly up-regulated the activity of detoxification enzymes: heme oxygenase 1 (HO-1), glutathione transferase, glutathione peroxidase, superoxide dismutase and quinone reductase. Nrf2 translocation into the nucleus was also observed by immunocytochemistry analysis. These data demonstrate the protective effect of PC against CTN-induced oxidative stress in HepG2 cells and up-regulated the activity of detoxification enzyme levels through Keap1/Nrf2 signaling pathway.
Aim
In this study polyphenols from pomegranate peel, and n‐3 fatty acids with polyphenols from flax seed were evaluated for their anti depression properties in mice exposed to chronic mild stress ...(CMS).
Methods
A total of 40 mice initially trained to consume 2% sucrose solution for 3 weeks were then divided into five groups of eight each. The first group was the normal control, the remaining four groups were exposed to CMS but were force fed with either: 10 mL water per kg bodyweight per day; imipramine (a standard antidepressant) 15 mg kg bodyweight; 30 mg per kg bodyweight polyphenol equivalent extract from pomegranate peel; or 30 mg polyphenols per kg bodyweight with omega‐3 fatty acids present, for 50 days. At the end, blood and brain were analyzed for various biomarkers of depression.
Results
The flax seed and imipramine groups had significantly increased sucrose consumption, decreased cortisol (blood), decreased epinephrine and norepinephrine concentration, decreased monoamine oxidase A and B activity, and decreased superoxide dismutase activity. Lipid peroxidation was completely inhibited. In contrast, pomegranate peel extract also completely inhibited lipid peroxidation in the brain, and reduced enzyme activity and hormone concentration but to a lesser extent than flax seed.
Conclusion
Polyphenols from flax seed with omega‐3 fatty acids were able to reduce all the CMS effects tested compared to polyphenols from pomegranate peel.
► Cyperus rotundus rhizome extract (CRE) attenuated peroxynitrite induced neurotoxicity. ► CRE inhibited NO generation by downregulating i-NOS expression. ► Peroxynitrite induced depletion of ...antioxidant enzyme status was restored. ► CRE pretreatment potentiated the peroxynitrite induced apoptotic biomarkers. ► Findings suggest that CRE might be developed as a preventive agent against apoptosis.
Nitrosylation of tyrosine (3-nitro tyrosine, 3-NT) has been implicated in the pathophysiology of various disorders particularly neurodegenerative conditions and aging. Cyperus rotundus rhizome is being used as a traditional folk medicine to alleviate a variety of disorders including neuronal stress. The herb has recently found applications in food and confectionary industries also. In current study, we have explored the protective effects of C. rotundus rhizome extract (CRE) through its oxido-nitrosative and anti apoptotic mechanism to attenuate peroxynitrite (ONOO−) induced neurotoxicity using human neuroblastoma SH-SY5Y cells. Our results elucidate that pre-treatment of neurons with CRE ameliorates the mitochondrial and plasma membrane damage induced by 500μM SIN-1 to 80% and 24% as evidenced by MTT and LDH assays. CRE inhibited NO generation by downregulating i-NOS expression. SIN-1 induced depletion of antioxidant enzyme status was also replenished by CRE which was confirmed by immunoblot analysis of SOD and CAT. The CRE pre-treatment efficiently potentiated the SIN-1 induced apoptotic biomarkers such as bcl-2 and caspase-3 which orchestrate the proteolytic damage of the cell. The ONOO− induced damage to cellular, nuclear and mitochondrial integrity was also restored by CRE. Furthermore, CRE pre-treatment also regulated the 3-NT formation which shows the potential of plant extract against tyrosine nitration. Taken together, our findings suggest that CRE might be developed as a preventive agent against ONOO− induced apoptosis.
Buffer type, pH and ionic strength, as well as the fraction of polyvinylpyrrolidone were optimized for efficient extraction of β-galactosidase from almond seeds. The enzyme was purified up to ...electrophoretic homogeneity employing (NH.sub.4).sub.2SO.sub.4(15-60%) fractionation, size exclusion and ion-exchange chromatography. Molecular mass of β-galactosidase as estimated by gel filtration and SDS-PAGE was approx. 62 kDa, confirming its monomeric nature. The optimum activity of the enzyme was at pH=5.5, and it was stable within the range of pH=5.0-6.0. Various kinetic parameters of β-galactosidase thermal inactivation were calculated: ΔH°, ΔS° and ΔG° suggested that the enzyme undergoes significant processes of unfolding during denaturation. Using β-galactosidase from almond seed powder, lactose hydrolysis in milk up to approx. 50 % was observed. The findings indicate the potential use of almond seeds for the production of low/delactosed milk for lactose-intolerant population. Key words: almond, β-galactosidase extraction, lactose intolerance, thermodynamic characterization
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