排序方式: 共有5条查询结果,搜索用时 15 毫秒
1
1.
Dimitrios A. Diamantis Sarka Ramesova Christos M. Chatzigiannis Ilaria Degano Paraskevi S. Gerogianni Konstantina E. Karadima Sonia Perikleous Dimitrios Rekkas Ioannis P. Gerothanassis Dimitrios Galaris Thomas Mavromoustakos Georgia Valsami Romana Sokolova Andreas G. Tzakos 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(9):1913-1924
Background
Flavonoids possess a rich polypharmacological profile and their biological role is linked to their oxidation state protecting DNA from oxidative stress damage. However, their bioavailability is hampered due to their poor aqueous solubility. This can be surpassed through encapsulation to supramolecular carriers as cyclodextrin (CD). A quercetin- 2HP-β-CD complex has been formerly reported by us. However, once the flavonoid is in its 2HP-β-CD encapsulated state its oxidation potential, its decomplexation mechanism, its potential to protect DNA damage from oxidative stress remained elusive. To unveil this, an array of biophysical techniques was used.Methods
The quercetin-2HP-β-CD complex was evaluated through solubility and dissolution experiments, electrochemical and spectroelectrochemical studies (Cyclic Voltammetry), UV–Vis spectroscopy, HPLC-ESI-MS/MS and HPLC-DAD, fluorescence spectroscopy, NMR Spectroscopy, theoretical calculations (density functional theory (DFT)) and biological evaluation of the protection offered against H2O2-induced DNA damage.Results
Encapsulation of quercetin inside the supramolecule's cavity enhanced its solubility and retained its oxidation profile. Although the protective ability of the quercetin-2HP-β-CD complex against H2O2 was diminished, iron serves as a chemical stimulus to dissociate the complex and release quercetin.Conclusions
We found that in a quercetin-2HP-β-CD inclusion complex quercetin retains its oxidation profile similarly to its native state, while iron can operate as a chemical stimulus to release quercetin from its host cavity.General significance
The oxidation profile of a natural product once it is encapsulated in a supramolecular carrier was unveiled as also it was discovered that decomplexation can be triggered by a chemical stimilus. 相似文献2.
Dimitrios Dimitroulis Demetrios Moris Emmanouil Pikoulis Eleftherios Spartalis Georgios Kontadakis Bart Vrugt Serena Valsami Gregory Kouraklis 《PloS one》2015,10(10)
Background
It is observed that combined liver and colon surgery especially when this includes major liver resection with Pringle maneuver (PM) performance does not have a favorable outcome. Aim of our experimental study is to investigate the impact of portal triad occlusion on the large bowel and intra-abdominal inflammation and potent protective effects of the variants of (PM) in the combined surgical cases.Materials and Methods
Forty-four rats were divided into four groups. In group A (control group), 1cm of the left partial colon was resected and then an end-to-end anastomosis was performed. In group B, a continuous PM for 30 minutes was performed followed by resection of 1cm of the left colon and an end-to-end anastomosis. In group C, the left colonic resection and anastomosis was performed after intermittent PM (IPM), which was 10 minutes PM followed by 5 minutes reperfusion repeated for three circles. In group D, an ischemic preconditioning for 10 minutes was initially performed followed by 5 minutes reperfusion and then continuous PM for 30 minutes. Finally the rats in group D underwent a 1cm left colonic resection and an end-to-end anastomosis.Results
The percentage of colitis was higher in the B group (P = 0,19). The percentage of inflammation was not significantly higher even when we compared all “occlusion” groups (B+C+D) with the sham group. No evidence of pancreatitis was found in the sham group whereas amylase and lipase levels were higher in Groups B, C and D together (P = 0,0267). The comparison of group A to group B showed a significant difference (P = 0,0014) caused by continuous PM for 30 minutes, but there was no such result after IPM.Conclusions
Major liver resections are performed with PM in order to minimize intra-operative blood loss. In the combined cases of colon surgery and major liver resections where PM is needed our results showed that IPM presents with better outcome and could be preferred compared with the other PM variants. 相似文献3.
Nazos Theocharis T. Kokarakis Emmanuel J. Valsami Eleftheria-Angeliki Stratigakis Napoleon-Christoforos Poloniataki Eleni G. Sfendourakis Georgios P. Ghanotakis Demetrios F. 《Photosynthesis research》2020,143(3):315-334
Photosynthesis Research - A herbicide and antibiotic-resistant microalgal strain, isolated from a eutrophic site at Giofyros river (Heraklion, Crete, Greece) was extensively characterized. In the... 相似文献
4.
Valsami Eleftheria-Angeliki Pateraki Angeliki Melis Anastasios Ghanotakis Demetrios F. 《Journal of applied phycology》2021,33(4):2157-2168
Journal of Applied Phycology - The aim of the present work was the investigation of various cultivation conditions in order to provide a foundation for a sustainable, financially viable, and... 相似文献
5.
Stratos Maragos Helen Archontaki Panos Macheras Georgia Valsami 《AAPS PharmSciTech》2009,10(4):1444-1451
Praziquantel (PZQ), the primary drug of choice in the treatment of schistosomiasis, is a highly lipophilic drug that possesses
high permeability and low aqueous solubility and is, therefore, classified as a Class II drug according to the Biopharmaceutics
Classification System (BCS). In this work, β-cyclodextrin (β-CD) and hydroxypropyl-β-cyclodextrin (HP-β-CD) were used in order
to determine whether increasing the aqueous solubility of a drug by complexation with CDs, a BCS-Class II compound like PZQ
could behave as BCS-Class I (highly soluble/highly permeable) drug. Phase solubility and the kneading and lyophilization techniques
were used for inclusion complex preparation; solubility was determined by UV spectroscopy. The ability of the water soluble
polymer polyvinylpyrolidone (PVP) to increase the complexation and solubilization efficiency of β-CD and HP-β-CD for PZQ was
examined. Results showed significant improvement of PZQ solubility in the presence of both cyclodextrins but no additional
effect in the presence of PVP. The solubility/dose ratios values of PZQ-cyclodextrin complexes calculated considering the
low (150 mg) and the high dose (600 mg) of PZQ, used in practice, indicate that PZQ complexation with CDs may result in drug
dosage forms that would behave as a BCS-Class I depending on the administered dose. 相似文献
1