Biomedical subjects

Gunes Ozhan

Publications and source records attributed to Gunes Ozhan.

3 recordsLinked to original sources

PubMed2026

Bioactivity and developmental toxicity of Raphanus raphanistrum: integrating phytochemistry, in vitro assays, and zebrafish model.

Raphanus raphanistrum L. (wild radish), a member of the Brassicaceae family, is an edible herb widely utilized in traditional medicine for the treatment of various ailments. This study aimed to evaluate the chemical composition, antioxidant capacity, enzyme inhibitory potential, and cytotoxic activity of extracts derived from its aerial parts. Among the tested extracts, the 70% ethanol extract contained the highest total phenolic content. A total of 38 compounds, mainly phenolic acids and flavonoids, were identified by HPLC-ESI-MS/MS analysis. The aqueous extract contained the highest levels of individual phenolic compounds, particularly ferulic acid and p-coumaric acid. The 70% ethanol extract showed the strongest antioxidant activity in all assays. The ethyl acetate extract exhibited the highest acetylcholinesterase and α-amylase inhibitory activities. Cytotoxicity assays revealed that the 70% ethanol extract was active against A549 lung cancer cells with an IC50 value of 56.77 µg mL-1 and a selectivity index of 1.6. In vivo zebrafish developmental toxicity assays demonstrated dose-dependent embryotoxic effects. Early exposure (0 hpf) caused increased mortality, reduced hatching, and morphological abnormalities, such as axial curvature and pericardial edema, whereas exposure at 72 hpf showed markedly reduced sensitivity. Overall, the findings suggest that R. raphanistrum is a promising natural source of bioactive compounds that could be used in the nutraceutical, pharmaceutical and cosmeceutical industries.

Journal Article↗

PubMed2025

Toxicological Assessment of Melamine-Functionalized Graphene Oxide and Carbon Nanotubes Using Zebrafish Models.

Graphene oxide (GO) and carbon nanotube (CNT)-based nanomaterials have attracted significant interest in various industrial and biomedical applications due to their unique physicochemical properties; however, concerns about their potential toxicity, especially when modified with additives like melamine (M), remain largely unresolved. This study investigates the toxicological effects and underlying mechanisms of graphene oxide-melamine (GO-M) and carbon nanotube-melamine (CNT-M) nanoparticles in zebrafish (Danio rerio) embryos and larvae. To this end, developmental toxicity, phenotypic and behavioral changes, as well as histopathological and immunofluorescence alterations, were evaluated following acute exposure to GO-M and CNT-M nanoparticles at concentrations of 5, 10, and 20 mg/L. Results showed that both nanoparticles delayed larval hatching, particularly at higher concentrations (10 and 20 mg/L). Malformations were observed at 20 mg/L in the GO-M group and at 10 and 20 mg/L in the CNT-M group. Additionally, significant changes in larval length and eye area were observed at all concentrations for both nanoparticles. Behavioral assessments revealed that CNT-M exposure at 10 and 20 mg/L significantly impaired head sensorimotor reflexes, while all concentrations affected tail reflexes. In contrast, GO-M exposure did not significantly alter sensorimotor responses. These findings suggest differential toxic mechanisms and neurobehavioral effects of GO-M and CNT-M nanoparticles during early zebrafish development.

Animals↗

PubMed2018

Thioredoxin interacting protein promotes invasion in hepatocellular carcinoma.

BACKGROUND: Considerable evidence suggests that oxidative stress plays an essential role in the progression of hepatocellular carcinoma (HCC). While acquired resistance to oxidative stress is the main driver of aggressive cell phenotype, the underlying mechanisms remain unknown. Here, we tested the hypothesis that elevated expression of Thioredoxin-interacting protein (TXNIP) is a main regulator of the aggressive phenotype in HCC. MATERIALS AND METHODS: To test this hypothesis, we measured TXNIP expression levels in 11 HCC cell lines by qPCR and western blotting. In addition, 80 pairs of HCC tissues and matched liver tissues of 73 cases, as well as 11 normal liver tissue samples were examined by immunohistochemistry. Besides, TXNIP expression levels were analyzed by Oncomine Platform in seven independent microarray datasets. Finally, the functional role of TXNIP in HCC was investigated in vitro and in vivo by silencing and overexpression studies. RESULTS: Our results show that TXNIP expression is significantly increased in HCC compared to non-tumor counterparts (p < 0.0001) as well as to normal (p < 0.0001) and cirrhotic (p < 0.0001) liver tissues. Moreover, stable overexpression of TXNIP in HCC cells (i) significantly increases ROS levels, (ii) induces EMT phenotype, (iii) increases motility, invasion and 3D branching tubulogenesis, (iv) decreases apoptosis, and (v) elevates in vivo metastasis in zebrafish embryos. Finally, we identify sinusoidal/stromal and cytoplasmic TXNIP staining patterns as risk factors for intrahepatic vascular invasion (p:0.0400). CONCLUSION: Our results strongly suggest that overexpression of TXNIP has a pivotal role in HCC progression by inducing cell survival, invasion, and metastasis.

EMT↗