Akyüz, Sümeyye

Objective: This study aimed to investigate the antimicrobial activity of Niaouli Essential Oil (Melaleuca quinquenervia), a commercially available oil known for its antiseptic, antimicrobial, antioxidant, anti-inflammatory, and antiprotozoal properties due to its bioactive constituents, against eight different standard bacterial strains, two standard yeast strains, and one clinical Candida isolate. Methods: The antimicrobial activity of niaouli essential oil against the isolates was evaluated using the disk diffusion and broth microdilution methods in accordance with EUCAST and CLSI guidelines. Ten of the microbial strains were American Type Culture Collection (ATCC) strains, and one was a clinical Candida auris isolate. The isolates were obtained from the strain collection of our university. Results: In this study, the disk diffusion method revealed that niaouli essential oil (Melaleuca quinquenervia) was most effective against Staphylococcus aureus (20 ± 0.0 mm) and Streptococcus pneumoniae (17.3 ± 0.57 mm) among the bacterial strains, and against Candida albicans (20.6 ± 0.57 mm) among the fungal strains. The Candida auris isolate exhibited an inhibition zone of 16.0 ± 1.0 mm. The lowest MIC values determined by the broth microdilution method were 62.5 μg/mL for both S. aureus and C. albicans. Among the Gram-negative isolates, Klebsiella pneumoniae was the most susceptible (125 μg/mL), whereas Pseudomonas aeruginosa, Salmonella enteritidis, and Enterococcus faecalis were the least susceptible (>250 μg/mL). The MIC value for C. auris was determined to be 250 μg/mL, which is one dilution higher than the positive control (fluconazole: 125 μg/mL). Conclusion: Niaouli essential oil demonstrated antimicrobial activity against standard microbial strains, with varying levels of antibacterial and antifungal effects. According to both methods used, it was more effective against Gram-positive bacteria and fungi than Gram-negative bacteria. While it was particularly effective against Candida albicans among the yeasts, it also exhibited antimicrobial activity against the increasingly important Candida auris strain. Due to the increasing resistance to antibacterial and antifungal agents, further studies investigating alternative treatment options are needed.

Çİçek, Betül; Taghİzadehghalehjoughİ, Ali; Yildirim, Serkan; Eser, Gizem; Gül, Mustafa; Kantarci, Mecit; Hacimüftüoğlu, Ahmet

Objective: Oxytocin (OXT) has been reported to have promising therapeutic potential due to its antioxidant properties in vincristine (VCR) and cisplatin (CP) induced peripheral neuropathy in both in vivo and in vitro studies. The cerebral cortex is responsible for sense, perception, and memory. Damage to these parts of the brain can lead to impairment of central nervous system functions. However, the effectiveness of OXT in toxicity caused by vincristine and cisplatin in cortical neurons has not been reported. In this study,we aimed to investigate the effects of OXT in VCR and CP-induced cortical neuron cell culture toxicity via biochemically measuring TAS-TOS levels and immunohistochemically determining 8-OHDG expression. Methods: Cortical neuronal cells were exposed to different concentrations of VCR and CP, and also after the neuronal cells were exposed to OXT (1 μM) for 5 minutes, VCR and CP concentrations were applied to the cells. Cell viability was determined using the MTT method. TAC and TOS were measured for antioxidant/oxidant activity. The expression of 8-OHdG was investigated as an indicator of oxidative DNA damage. Results: Administration of OXT before CP and VCR exposure was able to protect against neuronal cytotoxicity. TAS levels increased positively correlated with in cells exposed to OXT+ VCR and OXT+ CP, while TOS levels and DNA damage (8-OHdG levels) negatively correlated. Conclusion: OXT alleviated the toxic effects of VCR and CP-induced cortical neuron toxicity by increasing the TAS levels, while decreasing TOS levels and DNA damages. According to the results of this study, OXT has the potential to be used protective agent for anticancer agents induced toxicity. However, further studies are needed to clarify mechanisms of action of OXT.

Yılmaz, Sevil Karahan; Ayaz, Aylin

Metabolik sendrom tüm dünyada giderek yaygınlaşan kardiyometabolik komplikasyonları ile yüksek morbidite ve mortaliteye sahip önemli bir halk sağlığı sorunudur. Kalıtımla gelen bazı özellikler dışında hareketsiz yaşam tarzı, yanlış beslenme alışkanlıkları gibi çevresel etmenler metabolik sendrom için risk faktörü oluşturmaktadır. Metabolik sendromun önemli komponentleri; dislipidemi (HDL düzeyi düşüklüğü, artmış trigiserid düzeyi), hiperglisemi, yüksek kan basıncı ve abdominal obezitedir. Metabolik sendromu oluşturan beş ana komponent dışında temelinde insülin direncinin rol oynadığı düşünülen birçok klinik tabloda bu sendromun klinik yansımaları olarak kabul edilmektedir. Metabolik sendromun klinik yansımaları; diyabet, esansiyel hipertansiyon, visseral obezite, kardiyovasküler rahatsızlıklar, insülin direnci, osteoporoz, polikistik over sendromu, dislipidemi, hiperkoagulabilite, hiperürisemi, kemik mineral yoğunluğu, yağlı karaciğer ve uyku apnesidir. Son yıllarda D vitamininin, şişmanlık ve insülin direncinin neden olduğu hastalıkların oluşumunu önlediği, eksikliğinin ise bu hastalıkların ortaya çıkmasını kolaylaştırdığı ileri sürülmektedir. D vitamini yetersizliği gelişmiş ve gelişmekte olan ülkelerde prevalansı giderek artan bir halk sağlığı sorunudur. D vitamini yağda eriyebilen bir vitamin olmasına karşın, vücutta sentez edilen ve sentezlendiği yerin dışında farklı bölgelerde etki göstermesi nedeniyle günümüzde bir hormon olarak ta tanımlanmaktadır. Kalsiyum dengesi üzerine bilinen olumlu etkilerinin yanı sıra, endokrin sistemle ilgili fizyolojik işlevlere de sahiptir. Vitamin D düzeyini gösteren en iyi gösterge serum 25(OH)D düzeyidir. D vitamini alımı ve 25(OH)D düzeyinin obezite, metabolik sendrom ve diyabetle ilişkili olduğu bildirilmektedir. Vitamin D ile ilişkisi en çok araştırılan hastalıklar; kardiyovasküler hastalıklar, böbrek hastalıkları, diyabet, obezite, metabolik sendromdur. Bu derlemede D vitaminin metabolik sendrom bileşenlerinden insülin direnci, diyabet, obezite, hipertansiyon, dislipidemi, kardiyovasküler hastalıklar, yağlı karaciğer hastalığı, polikistik over sendromu ve kemik mineral yoğunluğu üzerine etkilerinin değerlendirilmesi amaçlanmıştır.