scholarly journals Characterization of a New Chitosanase from a Marine Bacillus sp. and the Anti-Oxidant Activity of Its Hydrolysate

Marine Drugs ◽  
2020 ◽  
Vol 18 (2) ◽  
pp. 126
Author(s):  
Chunrui Ma ◽  
Xiao Li ◽  
Kun Yang ◽  
Shangyong Li

Chitooligosaccharide (COS) has been recognized to exhibit efficient anti-oxidant activity. Enzymatic hydrolysis using chitosanases can retain all the amino and hydroxyl groups of chitosan, which are necessary for its activity. In this study, a new chitosanase encoding gene, csnQ, was cloned from the marine Bacillus sp. Q1098 and expressed in Escherichia coli. The recombinant chitosanase, CsnQ, showed maximal activity at pH 5.31 and 60 °C. Determination of CsnQ pH-stability showed that CsnQ could retain more than 50% of its activity over a wide pH, from 3.60 to 9.80. CsnQ is an endo-type chitosanase, yielding chitodisaccharide as the main product. Additionally, in vitro and in vivo analyses indicated that chitodisaccharide possesses much more effective anti-oxidant activity than glucosamine and low molecular weight chitosan (LMW-CS) (~5 kDa). Notably, to our knowledge, this is the first evidence that chitodisaccharide is the minimal COS fragment required for free radical scavenging.

2015 ◽  
Vol 2015 ◽  
pp. 1-10
Author(s):  
Kunlun Wang ◽  
Xiuhua Zhao ◽  
Yuangang Zu ◽  
Jialei Li ◽  
Xiaonan Zhang ◽  
...  

Ultrafine resveratrol (u-Res) particles were prepared through the SAS process. The orthogonal method was used to optimize the factors of the SAS process. The size of u-Res reached 0.68 μm under the optimum conditions. The characterization of the u-Res particles was tested by many analysis methods. The chemical structure of Res was unaffected by the SAS process. The degree of crystallinity of the u-Res particles greatly reduced. The purity of the u-Res particles increased from 98.5% to 99.2% during the SAS process. The u-Res particles had greater saturation solubility and dissolution rate than the raw-Res (r-Res) particles. The radical scavenging activity and bioavailability of the u-Res in vivo were 1.9 times of the r-Res.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Mohamed Makni ◽  
Raoua Jemai ◽  
Walid Kriaa ◽  
Yassine Chtourou ◽  
Hamadi Fetoui

Natural plant extracts contain a variety of phenolic compounds which are assigned various biological activities. Our work aims to make a quantitative and qualitative characterization of the Zest (ZL) and the Flesh (FL) of lemon (Citrus limon), to valorize the pharmacological uses of lemon, by evaluating in vitro activities (DPPH, free radical scavenging and reducing power). The antibacterial, antifungal, and antiproliferative activities were sought in the ability of Citrus limon extracts to protect DNA and protein. We found that the ZL contains high amounts of phenolics responsible for the important antioxidant properties of the extract. However, the FL is richer in flavonoids than the ZL. The FL extract was also found to be more effective than the ZL in protecting plasmid DNA against the strand breakage induced by hydroxyl radicals. We also concluded that the FL extract exhibited potent antibacterial activity unlike ZL. Analysis by LC/MS-MS identified 6 compounds (Caffeoyl N-Tryptophan, Hydroxycinnamoyl-Oglucoside acid, Vicenin 2, Eriocitrin, Kaempferol-3-O- rutinoside, and Quercetin-3-rutinoside). These preliminary results showed that Citrus limon has antibacterial and antioxidant activity in vitro. It would be interesting to conduct further studies to evaluate the in vivo potential in an animal model.


2015 ◽  
Vol 2 (10) ◽  
Author(s):  
Shofiul Azam ◽  
Prawej Ansari ◽  
Mohammad Mamun Ur Rashid ◽  
Mohammad Nazmul Alam ◽  
Ismail Hussein Ahmed ◽  
...  

2021 ◽  
Vol 26 ◽  
pp. 2515690X2110366
Author(s):  
Hope Onohuean ◽  
Abdullateef I. Alagbonsi ◽  
Ibe M. Usman ◽  
Keneth Iceland Kasozi ◽  
Athanasios Alexiou ◽  
...  

Background. Annona muricata and Khaya grandifoliola are ethnomedicinally used for the treatment of malaria and have been experimentally shown to have an anti-plasmodial effect, but the mechanisms involved are not fully understood. This study investigated the effect of the ethanol extracts of their leaves on parasitemia, radical scavenging and cytokines in Plasmodium berghei ANKA-infected BALB/c mice. Methods. BALB/c mice were infected with P. berghei and treated with chloroquine, A. muricata or K. grandifoliola extract for 4 days. The percentage of parasitemia and the level of cytokine expression were determined after treatment. Trace element, phytochemical and nitric oxide (NO) scavenging activity, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging properties assays were done to study the antioxidant effects of AN and KG in vitro. Results. P. berghei consistently increased parasitemia in BALB/c mice. The tested doses (100-, 200-, and 400 mg/kg) of A. muricata and K. grandifoliola attenuated the P. berghei-induced elevation of parasitemia and cytokines (TNF-α, IL-5, and IL-6) in vivo during the experimental period, though not as much as chloroquine. Moreover, both extracts scavenged the DPPH and NO radicals, though A. muricata had more anti-oxidant effect than K. grandifoliola in-vitro. Conclusion. The ethanol extracts of A. muricata and K. grandifoliola reduce parasitemia in P. berghei-treated mice BALB/c by scavenging free radicals and reducing cytokines, though the extracts were not as effective as chloroquine.


2007 ◽  
Vol 27 (1-3) ◽  
pp. 151-163 ◽  
Author(s):  
M. C. Lara ◽  
M. L. Valentino ◽  
J. Torres-Torronteras ◽  
M. Hirano ◽  
R. Martí

Over the last 15 years, important research has expanded our knowledge of the clinical, molecular genetic, and biochemical features of mitochondrial neurogastrointestinal encephalomyopathy (MNGIE). The characterization of mitochondrial involvement in this disorder and the seminal determination of its genetic cause, have opened new possibilities for more detailed and deeper studies on the pathomechanisms in this progressive and fatal disease. It has been established that MNGIE is caused by mutations in the gene encoding thymidine phosphorylase (TP), which lead to absolute or nearly complete loss of its catalytic activity, producing systemic accumulations of its substrates, thymidine (dThd) and deoxyuridine (dUrd). Findings obtained from in vitro and in vivo studies indicate that the biochemical imbalances specifically impair mitochondrial DNA (mtDNA) replication, repair, or both leading to mitochondrial dysfunction. We have proposed that therapy for MNGIE should be aimed at reducing the concentrations of these toxic nucleosides to normal or nearly normal levels. The first treatment, allogeneic stem-cell transplantation (alloSCT) reported in 2006, produced a nearly full biochemical correction of the dThd and dUrd imbalances in blood. Clinical follow-up of this and other patients receiving alloSCT is necessary to determine whether this and other therapies based on a permanent restoration of TP will be effective treatment for MNGIE.


2016 ◽  
Vol 3 ◽  
pp. 184954351667344
Author(s):  
Chukwuebuka Umeyor ◽  
Emmanuel Anaka ◽  
Franklin Kenechukwu ◽  
Chinazom Agbo ◽  
Anthony Attama

Newbouldia laevis (P. Beauv.) is a tropical rainforest plant used in traditional folk medicine for the treatment of malaria, cough, joint pains, stomach ache, oedema and inflammation. The main thrust of this research work was to study the analgesic/anti-nociceptive properties of N. laevis-loaded solid lipid microdispersions. N. laevis leaves were extracted using ethanol, and the extract was formulated into solid lipid microdispersions using lipid matrix comprising a rational blend of Precirol® ATO 5 and Softisan® 154. Characterization of the solid lipid microdispersions include determination of morphology, particle size, pH, thermal property, encapsulation efficiency percentage and analgesic/anti-nociceptive property. The results obtained showed that the particles were spherical with sizes ranging from 40 µm to 125 µm. The solid lipid microdispersions maintained a stable pH within the acidic region of 5–6 with insignificant variations ( p > 0.05) over a period of 90 days. Thermal analysis showed that N. laevis was entrapped in the lipid matrix used for the formulations. Solid lipid microdispersions recorded a maximum encapsulation efficiency up to 88.1%. N. laevis-loaded solid lipid microdispersions also produced good analgesic/anti-nociceptive property comparable with the standard diclofenac potassium. N. laevis-loaded solid lipid microdispersions showed good analgesic/anti-nociceptive effect and could be used in the treatment and management of pain.


2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Camila Gabriela de Souza ◽  
Daniela Medeiros Lobo de Andrade ◽  
Juliana Bahia Reis Jordão ◽  
Renato Ivan de Ávila ◽  
Leonardo Luiz Borges ◽  
...  

Jabuticaba is an exotic fruit native to Brazil that has been arousing medicinal interest. Using chemical (HPLC-PDA, resonance mass spectra, and NMR), electroanalytical (differential pulse voltammetry, radical scavenging assay), and pharmacological (in vivo and in vitro) approaches, we have identified its bioactive compounds and hypotensive effects on hypertensive rats. The hydroalcoholic extract of jabuticaba (HEJ) presents a great quantity of phenolic compounds, and several molecules with hydroxyl groups present high efficiency as an antioxidant. The treatment with HEJ (100 and 300 mg/kg/day, for four weeks) presented hypotensive effects on L-NAME-induced hypertensive rats, possibly improving the nitric oxide bioavailability because of its high antioxidant potential. Furthermore, renal and cardiac hypertrophies were also attenuated after the HEJ treatment. Moreover, the vascular responses to contractile and dilating agonists were improved with the HEJ treatment, which is also able to induce nitric oxide production in endothelial cells.


Author(s):  
GURVIRENDER SINGH ◽  
SUPRIYA AGNIHOTRI ◽  
SANTOSH KUMAR VERMA

The study was aimed to trace out antihyperglycemic potentials of Nymphaea alba leaves using in vitro and in vivo approaches. In, in vitro study, determination of IC50 of Nymphaea alba extracts was done using α-amylase and α-glucosidase inhibition assay. In α-amylase, Nymphaea alba methanol extract (NAME) exhibited maximum inhibition 56.77±1.23% at 125µg/ml in comparison to 66.7±0.94 % of standard acarbose. In α-glucosidase, NAME exhibits 59.89±0.92, while standard acarbose showed 70.31±1.25 % inhibition. The in vivo study was performed on diabetic rats, made diabetic by Streptozotocin. 200mg/kg and 400mg/kg NAME was administered orally, which significantly (


1999 ◽  
Vol 342 (3) ◽  
pp. 567-580 ◽  
Author(s):  
Peter J. MULQUINEY ◽  
William A. BUBB ◽  
Philip W. KUCHEL

This is the first in a series of three papers [see also Mulquiney and Kuchel (1999) Biochem. J. 342, 579-594; Mulquiney and Kuchel (1999) Biochem. J. 342, 595-602] that present a detailed mathematical model of erythrocyte metabolism which explains the regulation and control of 2,3-bisphosphoglycerate (2,3-BPG) metabolism. 2,3-BPG is a modulator of haemoglobin oxygen affinity and hence plays an important role in blood oxygen transport and delivery. This paper presents an in vivo kinetic characterization of 2,3-BPG synthase/phosphatase (BPGS/P), the enzyme that catalyses both the synthesis and degradation of 2,3-BPG. Much previous work had indicated that the behaviour of this enzyme in vitro is markedly different from that in vivo. 13C and 31P NMR were used to monitor the time courses of selected metabolites when erythrocytes were incubated with or without [U-13C]glucose. Simulations of the experimental time courses were then made. By iteratively changing the parameters of the BPGS/P part of the model until a good match between the NMR-derived data and simulations were achieved, it was possible to characterize BPGS/P kineticallyin vivo. This work revealed that: (1) the pH-dependence of the synthase activity results largely from a strong co-operative inhibition of the synthase activity by protons; (2) 3-phosphoglycerate and 2-phosphoglycerate are much weaker inhibitors of 2,3-BPG phosphatase in vivo than in vitro; (3) the Km of BPGS/P for 2,3-BPG is significantly higher than that measured in vitro; (4) the maximal activity of the phosphatase in vivo is approximately twice that in vitro, when Pi is the sole activator (second substrate); and (5) 2-phosphoglycollate appears to play no role in the activation of the phosphatase in vivo. Using the newly determined kinetic parameters, the percentage of glycolytic carbon flux that passes through the 2,3-BPG shunt in the normal in vivo steady state was estimated to be 19%.


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