Zehra Öksüz

1. One of the most critical public health problems of the 21st century is the rapid global spread of antibiotic-resistant bacteria [1]. The World Health Organization’s 2024 Bacterial Priority Patho...

This study provides the first detailed evaluation of C. erecta latex, an uncharacterised exudate of the Apocynaceae family, focusing on its phytochemical composition and bioactivity. HPLC analysis revealed nine phenolic compounds, mainly sinapic acid (4876.2 µg/g), ferulic acid (902.6 µg/g), and epicatechin (386.5 µg/g). Although the total phenolic content was relatively low (2.27 ± 4.2 mg GAE/g), DPPH assay indicated moderate antioxidant activity (IC₅₀ = 114 µg/mL), suggesting contributions from other bioactive constituents. Volatile profiling via HS-SPME-GC-MS and solvent-assisted GC-MS identified compounds such as p-cymene (14.05%), 2-hexanol (12.52%), and kaur-16-ene (72.06%). The latex exhibited antimicrobial activity against bacteria and yeasts, with MIC values ranging from 62.5 to 250 µg/mL, showing higher effectiveness against Acinetobacter baumannii, Candida parapsilosis, and Candida glabrata. Overall, the findings highlight C. erecta latex as a phenol- and terpenoid-rich natural product with promising antioxidant and antimicrobial potential, supporting its traditional dermatological use and future pharmaceutical relevance.

Background Chemokines and their receptors, which regulate lymphoid organ development and immune cell trafficking, are integral to the mechanisms underlying viral control, hepatic inflammation, and liver damage in chronic hepatitis C (CHC) infection. This study explores the potential relationship between serum chemokine levels/polymorphisms and hepatitis C infection in affected individuals, with a particular focus on their utility as biomarkers across different stages of fibrosis. Methods and results Serum levels of the chemokines CXCL11, CXCL12, and CXCL16 were measured in patients with mild/moderate and advanced fibrosis due to CHC, as well as in healthy controls, using the ELISA method. The CXCL12 rs1801157 and CXCL16 rs2277680 polymorphisms were analyzed in blood samples from patients and healthy controls through RT-qPCR. Serum levels of CXCL11, CXCL12, and CXCL16 were significantly elevated in patients with advanced fibrosis compared to healthy controls. Furthermore, CXCL11 levels were markedly higher in patients with advanced fibrosis than in those with mild/moderate fibrosis. The frequency of the CXCL12 rs1801157 AA genotype was significantly higher in the advanced fibrosis group compared to the healthy control group. Similarly, the CXCL16 rs2277680 GA genotype was significantly more prevalent in the advanced fibrosis group than in the mild/moderate fibrosis group. Conclusions The current study highlights that, in addition to the potential association between chemokine levels/polymorphisms and an increased risk of disease complications and pathological progression in CHC infection, serum CXCL11 levels and the CXCL16 rs2277680 allel polymorphism may be important factors in determining the fibrosis stage of hepatitis C infection.

The expression of miR-223-3p, miR-17-5p, and miR-24-3p was evaluated in hepatitis C virus (HCV) patient serum samples, collected before DAA treatment and after a sustained virological response (SVR). Fifty HCV patients were stratified based on their liver damage stages into three different subgroups (21 with chronic hepatitis—CH, 15 with cirrhosis, and 14 with hepatocellular carcinoma—HCC). Considering the entire HCV population, the miRNA expression levels were significantly downregulated after the SVR compared to pre-treatment ones (p < 0.05). Stratifying the patients based on liver damage, the post-SVR values of the three miRNAs were significantly downregulated compared to the pre-treatment levels for both cirrhosis and HCC patients. No significant differences emerged from the analysis of the CH group. To our knowledge, this is the first study to detail the behavior of miR-223-3p, miR-17-5p, and miR-24-3p levels in patients with HCV-related CH, cirrhosis, and HCC after DAA therapy. Our findings show that HCV-infected patients have different miRNA profiles before and after treatment with DAAs, strongly suggesting that miRNAs may be involved in the pathogenesis of HCV-related damage. In this respect, the correlation observed among the three studied miRNAs could imply that they share common pathways by which they contribute the progression of HCV-induced chronic liver damage.

Bu araştırmada, Trigonella mesopotamica Hub.-Mor. tohum, toprak üstü ve tohum kabuğu kısımlarından elde edilen etanol ekstrelerinin antimikrobiyal ve antibiyofilm aktivitelerinin değerlendirilmesi amaçlanmıştır. Antimikrobiyal aktivite, in vitro mikrodilüsyon yöntemi kullanılarak referans bakteri ve mantar suşları üzerinde gerçekleştirilmiştir. Bunlara ek olarak, ekstrelerin P. aeruginosa'nın biyofilm oluşumunu engelleme ve önceden oluşturulmuş biyofilmi yok etme potansiyeli kristal viyole yöntemi kullanılarak belirlenmiştir. Ekstreler, referans antimikrobiyallerle karşılaştırıldığında test edilen bakteri ve mayalara karşı orta ila düşük antimikrobiyal aktivite göstermiştir. Ekstreler ayrıca biyofilm oluşumunu inhibe etme ve farklı minimum inhibitör konsantrasyonlarında (MIC) önceden oluşturulmuş biyofilmleri önleme potansiyeli göstermiştir. Tohum ve toprak üstü ekstrelerinin, tohum kabuğu ekstresine kıyasla daha iyi antibiyofilm aktivitesi gösterdiği belirlenmiştir. Özellikle veriler göz önüne alındığında, toprak üstü ekstresinin sub-MIC'de biyofilm oluşumunu %50 oranında azaltması ilgi çekicidir. Bulgular, T. mesopotamica'nın farklı kısımlarının özellikle antibiyofilm aktivitesi gösterdiğini kanıtlamaktadır. Literatürde ilk kez bu çalışma ile T. mesopotamica'nın antimikrobiyal ve antibiyofilm aktivitesine ilişkin veriler sunulmuştur. Bu nedenle çalışmamız bu türle ilgili literatüre önemli ön veriler sağlamaktadır.

Amaç: Bu çalışmanın amacı bazı türleri geleneksel olarak nevroz, sıtma, skrofula, uyuz, ateş, eksternal kanserler, incinme ve yara tedavisinde kullanılan Vincetoxicum cinsine ait iki taksonun (Vincetoxicum canescens subsp. pedunculata (VC) ve Vincetoxicum fuscatum subsp. fuscatum (VF)) tohumlarının antimikrobiyal, antibiyofilm aktiviteleri ve sinerjik etkilerini incelemektir.Yöntem: Öğütülmüş tohumlardan elde edilmiş etanollü ekstrelerin antimikrobiyal etkinlikleri mikrodilüsyon yöntemiyle 5 referans bakteri suşu (Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, Klebsiella pneumoniae) ve 2 referans maya suşuna (Candida albicans and Candida parapsilosis) karşı test edilmiştir. Ayrıca ekstrelerin P. aeruginosa’nın biyofilm oluşumunu inhibe etme ve oluşmuş biyofilm üzerine etkisi kristal viyole yöntemi ile değerlendirilmiştir. Biyofilm testleri ile minimum biyofilm inhibisyon konsantrasyonu (MBIC50) ve minimum biyofilm azaltma konsantrasyonu (MBRC50) belirlenmiştir. E.coli'ye karşı iki ekstre arasındaki sinerjik etkiyi değerlendirmek için ise mikrodilüsyon dama tahtası yöntemi kullanılmıştır.Bulgu: Ekstreler, test edilen bakteri ve mayaları 62,5–250 µg/mL minimum inhibisyon konsantrasyonları (MİK) aralığında inhibe etmiştir. VF ve VC ekstrelerinin 0,5X ve 0,25X MİK'de biyofilm oluşumunu sırasıyla %47, %39 ve %50, %34 oranında inhibe ettiği ve iki ekstrenin MBIC50 değerinin 62,5 µg/mL olduğu belirlenmiştir. Ayrıca ekstrelerin önceden oluşmuş biyofilmi 1X ve 2X MİK'de sırasıyla %54, %62 ve %56, %61 oranında inhibe ettiği ve MBRC50 değerinin 125 µg/mL olduğu belirlenmiştir. Dahası ekstrelerin E.coli'ye karşı aditif etki (FİK=0,62) gösterdikleri de tespit edilmiştir.Sonuç: Test edilen ekstreler orta ve düşük antimikrobiyal etki göstermekle birlikte hem biyofilm oluşumunu engelleme hem de oluşmuş biyofilmi ortadan kaldırmada iyi etkinliğe sahiptir.

Biofilm-associated infections cause important health problems all over the world. Because of the resistance to antimicrobials and their possible side effects, researchers' attention has been focused on plant extracts and their components. The aim of this study is to evaluate the antimicrobial and antibiofilm potentials of Salvia microstegia Boiss. et Bal. mericarps. The antimicrobial activity of ethanolic extract obtained from the mericarps was evaluated using the microdilution method against seven standard bacteria and three standard yeast strains. In addition, the effect of the extract on inhibiting biofilm formation and preformed biofilm of Pseudomonas aeruginosa was determined using the crystal violet method. The used extract showed moderate to low antimicrobial activity against tested bacteria and yeasts with minimum inhibitory concentration (MIC) values ranging from 62.5 to 250 µg/mL. Moreover, the extract's potential to inhibit preformed biofilms was found to be greater compared to its potential to inhibit biofilm formation. In conclusion, the tested extract obtained from Salvia microstegia mericarps showed antibiofilm potential, however, additional studies involving different strains are needed to reveal its antimicrobial potential in a more holistic perspective.

In this study, it was aimed to determine the antimicrobial, antibiofilm activities and synergistic effects of ethanol extracts obtained from above-ground, root, seed and seed coat of Vincetoxicum hirundinaria Medic. Antimicrobial activity was performed against 7 bacterial and 3 fungal standard strains by microdilution method and minimum inhibition concentrations (MIC) were determined. The crystal violet method was applied to determine the prevention of biofilm formation and inhibition of preformed biofilm activities on P. aeruginosa biofilm. In addition, the synergistic effects of aerial part and seed extracts against both E. coli and E. faecalis were examined by the microdilution checkerboard method. According to the antimicrobial test results tested extracts had moderate to low efficacy against studied bacterial and yeast strains. The synergy test showed that the aerial and seed extracts had additive effect against both E. coli and E. faecalis. The extracts also showed the potential to inhibit biofilm formation and inhibit preformed biofilms. Root and seed pod extracts showed the strongest antibiofilm activity, while the aerial part extract was the weakest. In conclusion, our results prove that the tested extracts, especially obtained from root and seed pods and used in the treatment of many diseases, have potential in terms of antibiofilm activity. The literature search indicated that the antimicrobial and antibiofilm activities of V. hirundinaria was evaluated for the first time in the current study, therefore; our findings provide important preliminary data to the literature in terms of antibiofilm activity of V. hirundinaria

Although persistent sustained viral response rates are increased in hepatitis C infection following administration of direct-acting antiviral (DAA) agents, the pre-use predictive parameters of these antivirals and the clinical progression in patients post-treatment remain unknown. To obtain data pertaining to the predictive parameters prior to the use of ombitavir/paritaprevir/ritonavir + dasabuvir and the clinical progression in patients following antiviral treatment. The expression profiles of miR-223-3p, miR-17-5p, miR-24-3p, and TLR2 − 196 to − 174 del/ins polymorphisms from the blood/serum of 34 hepatitis C virus (HCV)-infected patients pre- and post-ombitavir/paritaprevir/ritonavir + dasabuvir treatment were determined by RT-qPCR. The expression levels of miR-17-5p (P < 0.001) and miR-24-3p (P = 0.011) were significantly downregulated post-treatment as compared with those pre-treatment; however, there was no significant difference between these two groups in terms of miR-223-3p expression. In addition, there was no significant difference in TLR2 genotype or allele distribution between pre-and post-treatment (P > 0.05); nevertheless, the TLR2 del allele was decreased post-treatment (16.2%) as compared with that pre-treatment (19.1%), although the difference was not statistically significant. Moreover, a significant difference was found between the mRNA levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and HCV RNA pre-and post-treatment (P < 0.05). Further, miR-17-5p expression correlated with both ALT and AST mRNA levels post-treatment (P