Yazar "Akar, Remzi Okan" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim
    Yayın
    Formulation and characterization of an oleuropein-enriched oral spray gel: Microbiological performance and in ovo histopathological safety
    (MDPI Publishing, 2026) Alparslan, Levent; Özdemir, Samet; Karacan, Burak; Tutar, Ömer Faruk; Doğan, Tunay; Akar, Remzi Okan; Yıldırım, Elifnur Gizem; Erdoğan, Nusret
    Background/Objectives: Oleuropein is a bioactive phenolic compound from olive leaves with antimicrobial and antioxidant activity. This study aimed to develop a sprayable oral gel containing an oleuropein-rich aqueous extract and to evaluate its pharmaceutical performance antimicrobial efficacy and in ovo biological response. Methods: Oleuropein content was quantified using a validated chromatographic method. Polymeric systems were screened to select an optimized sprayable formulation. Physicochemical stability, dose uni formity, and antimicrobial activity against major cariogenic bacteria were evaluated. In ovo biological evaluation was conducted using the chick chorioallantoic membrane angiogene sis model together with histopathological examination of embryonic heart and liver tissues. Results: Oleuropein content was determined as 288.6 µg/mL in the olive leaf extract and 255.1 µg/mL in the final formulation. The optimized oral spray showed stable physico chemical properties, with pH maintained at 6.90 ± 0.02 and no relevant changes in viscosity during storage. The mean delivered dose per actuation was 0.128 ± 0.015 g, corresponding to 32.6 µg oleuropein per spray. The formulation exhibited inhibitory activity against all tested cariogenic microorganisms, with MIC values ranging from 13.3 to 170.7 µg/mL and MBC values generally two-fold higher. In the CAM assay, significant concentration- and time-dependent antiangiogenic effects were observed after 24–48 h at moderate and higher concentrations. Histopathological evaluation revealed dose-dependent acute degenerative and congestive changes in heart and liver tissues without evidence of fibrosis or steatosis. Conclusions: The oleuropein-based sprayable oral gel is a promising localized delivery system with adequate stability dose uniformity and antimicrobial efficacy. In ovo findings provide a conservative assessment of systemic exposure and support further development for oral biofilm and caries-related applications.
  • Küçük Resim
    Yayın
    Pd(II) and Pt(II) saccharinate complexes with two phosphine derivatives: Synthesis, anticancer and antiangiogenic activities
    (Wiley Online Library, 2024) İçsel, Ceyda; Yılmaz, Veysel Turan; Aygun, Muhittin; Erkısa Genel, Merve; Ulukaya, Engin; Akar, Remzi Okan
    As clinically used anticancer Pt(II) drugs have severe side effects, there is a growing interest for new metal complexes with great potential for cancer therapy. The current work aimed to prepare and characterize new Pd(II) and Pt(II) saccharinate (sac) complexes bearing pyridyl- and benzyldiphenylphosphines (PPh2Py and PPh2Bz, respectively), cis-[Pd(sac)2(PPh2Py)2] (1), cis-[PtCl(sac)(PPh2Py)2]·0.5DMF (2), cis-[Pd(sac)2(PPh2Bz)2]·DMF (3) and trans-[PtCl(sac)(PPh2Bz)2] (4) as promising anticancer and antiangiogenic drugs. The anticancer activity of the complexes was screened against seven cancer cell lines including HCT116 (colon), HepG2 (liver), MDA-MB-231 (breast), PANC-1 (pancreatic), A549 (lung), C6 (glioma), DU145 (prostate) and normal human lung epithelial cells (BEAS-2B). 1 and 2 did not show biological activity below 20 μM at 48 h, whereas 3 and 4 displayed significant cytotoxic effect on the cancer cells. 4 was the most potent complex (IC50 = 2.2–12.1 μM) and displayed much greater cytotoxicity than cisplatin in all the cancer cell lines. 4 caused apoptosis in HCT116 cells as evidenced by annexin V positivity and caspase 3/7 activity assays. Furthermore, the inhibition of antiapoptotic Bcl-2 proteins by the complex suggested the intrinsic apoptosis. In addition, 4 greatly enhanced generation of intracellular reactive oxygen species (ROS) and consequently caused remarkable DNA double-strand breaks in HCT116 cells. Moreover, the chick chorioallantoic membrane (CAM) assay was used to evaluate antiangiogenic potential of 4. The complex effectively inhibited angiogenesis at a dose of 50 ng, suggesting it as a promising multi-targeted agent for antiangiogenic cancer treatment.