57 research outputs found

    Simultaneous analysis of major ingredients of Gardenia fruit by HPLC-MS/TQMS method

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    An efficient, accurate HPLC-MS/TQMS method was introduced for the quantitative/qualitative simultaneous analysis of main ingredients, namely geniposide and genipingentiobioside, in the Gardenia fruit. The separation was successfully obtained using a C8 (100mm×2.1mm, 5μm, 30°C) column by gradient elution with ultrapure water as mobile phase, where flow rate was set to 0.2 ml/min and detection wavelength at 240 nm. The analytical method was validated and the quantification of active compounds, namely genipingentiobioside and gardenoside, was performed. Linearity, precision, repeatability, stability and recovery were also reported. The quantitative analysis revealed that both main ingredients as geniposide and genipingentiobioside have performed a good linear relationship in 0.1-100 mg/ml concentration range (r=1.00000 and r =0.99998). The average content was measured to be 4.842% with RSD 0.96% for geniposide and 1.1976% with RSD 0.47% for genipingentiobioside in the Gardenia fruit. Accordingly, this method would be feasible for the quantity and quality control of crude drugs

    Carrageenan-based hydrogels for the controlled delivery of PDGF-BB in bone tissue engineering applications

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    One of the major drawbacks found in most bone tissue engineering approaches developed so far consists in the lack of strategies to promote vascularisation. Some studies have addressed different issues that may enhance vascularisation in tissue engineered constructs, most of them involving the use of growth factors (GFs) that are involved in the restitution of the vascularity in a damaged zone. The use of sustained delivery systems might also play an important role in the re-establishment of angiogenesis. In this study, !-carrageenan, a naturally occurring polymer, was used to develop hydrogel beads with the ability to incorporate GFs with the purpose of establishing an effective angiogenesis mechanism. Some processing parameters were studied and their influence on the final bead properties was evaluated. Platelet derived growth factor (PDGF-BB) was selected as the angiogenic factor to incorporate in the developed beads, and the results demonstrate the achievement of an efficient encapsulation and controlled release profile matching those usually required for the development of a fully functional vascular network. In general, the obtained results demonstrate the potential of these systems for bone tissue engineering applications.This work was supported by the European NoE EXPERTISSUES (NMP3-CT-2004-500283), the European STREP HIPPOCRATES (NMP3-CT-2003-505758), and by the Portuguese Foundation for Science and Technology (FCT) through the project PTDC/FIS/68517/2006 and through the V. Espirito Santo's Ph.D. grant (SFRH/BD/39486/2007)

    The anticancer activity of lytic peptides is inhibited by heparan sulfate on the surface of the tumor cells

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    <p>Abstract</p> <p>Background</p> <p>Cationic antimicrobial peptides (CAPs) with antitumor activity constitute a promising group of novel anticancer agents. These peptides induce lysis of cancer cells through interactions with the plasma membrane. It is not known which cancer cell membrane components influence their susceptibility to CAPs. We have previously shown that CAPs interact with the two glycosaminoglycans (GAGs), heparan sulfate (HS) and chondroitin sulfate (CS), which are present on the surface of most cells. The purpose of this study was to investigate the role of the two GAGs in the cytotoxic activity of CAPs.</p> <p>Methods</p> <p>Various cell lines, expressing different levels of cell surface GAGs, were exposed to bovine lactoferricin (LfcinB) and the designer peptide, KW5. The cytotoxic effect of the peptides was investigated by use of the colorimetric MTT viability assay. The cytotoxic effect on wild type CHO cells, expressing normal amounts of GAGs on the cell surface, and the mutant pgsA-745, that has no expression of GAGs on the cell surface, was also investigated.</p> <p>Results</p> <p>We show that cells not expressing HS were more susceptible to CAPs than cells expressing HS at the cell surface. Further, exogenously added heparin inhibited the cytotoxic effect of the peptides. Chondroitin sulfate had no effect on the cytotoxic activity of KW5 and only minor effects on LfcinB cytotoxicity.</p> <p>Conclusion</p> <p>Our results show for the first time that negatively charged molecules at the surface of cancer cells inhibit the cytotoxic activity of CAPs. Our results indicate that HS at the surface of cancer cells sequesters CAPs away from the phospholipid bilayer and thereby impede their ability to induce cytolysis.</p

    Anterior capsular contraction after cataract surgery in eyes of diabetic patients

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    AIM—To investigate change in the area of anterior capsular opening (ACO) after cataract surgery and its relation to the degree of postoperative anterior inflammation in patients with diabetes mellitus (DM).
METHODS—31 eyes of 31 patients with DM and 30 eyes of 30 normal controls scheduled to undergo cataract surgery were examined prospectively. The area of ACO was measured with an anterior eye segment analysis system (EAS-1000) on the day following surgery and 3, 6, and 12( )months after surgery. Comparative analyses were made on the area of ACO relative to the presence of DM and diabetic retinopathy (DR). The percentage reduction of area of ACO was calculated from values 1 day and 12 months after surgery, and multiple regression analysis was performed on the presence of DM, patient age, ACO area on the first postoperative day, and aqueous flare intensity 1 day and 12 months after surgery.
RESULTS—The area was significantly smaller in the DM group at 3 (p=0.015, Student's t test), 6 (p=0.011), and 12 (p=0.010) months postoperatively. Patients having DR showed significantly smaller ACO area than the non-DR group 3 (p=0.039), 6 (p=0.033), and 12( )(p=0.028) months after surgery. Multiple regression analysis revealed that presence of DM (p=0.003) and aqueous flare intensity 12 months after surgery (p=0.039) significantly correlated with the percentage reduction of area of ACO. Age, ACO area at 1 day postoperatively, and aqueous flare intensity immediately after surgery were not relevant to ACO contraction.
CONCLUSIONS—Anterior capsular contraction after cataract surgery was greater in eyes of DM patients, especially in those with DR and increased permeability of the blood-aqueous barrier.

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