Ayşegül Akkoyunlu

Amaç: Usnea longissima Ach. antibiyotik özellikleri nedeniyle geleneksel olarak bitkisel tedavide kullanılmıştır. Ancak, olası antikanser etkileri halen araştırılmaktadır. Gereç ve Yöntemler: HCT116 kolon kanseri ve HUVEC hücre hatları, 25-800 µg/mL konsantrasyonlarda U. longissima Ach. etanolik özütü ile muamele edildi ve hücre canlılığı WST-1 testi ile analiz edildi. İnsan Kaspaz-3, -8 ve -9 ELISA kitleri, özütün HCT116 hücrelerindeki apoptotik etkilerini araştırmak için kullanıldı. Migrasyon etkileri, HCT116 hücrelerinde yara iyileştirme testi ile değerlendirildi. Biyofilm inhibisyonu mikroplate yöntemi ile değerlendirildi ve anti-quorum sensing (QS) etkisi kuyu difüzyon yöntemi ile belirlendi. Bulgular: U. longissima Ach. etanolik özütü, 800 µg/mL'de HCT116 kolon kanseri hücrelerinde hücre canlılığı seviyesini %14'e düşürdü. HUVEC hücrelerinde, hücre canlılığındaki anlamlı olmayan azalma, U. longissima Ach.'nın sağlıklı hücreler üzerinde minimal sitotoksik etkiye sahip olduğunu gösterdi. HCT116 hücrelerinde Kaspaz-3 ve Kaspaz-9 ekspresyon seviyeleri kontrol grubuna kıyasla yaklaşık 5 kat arttı ve bu da özütün içsel apoptotik yanıtı indüklediğini gösterdi. Ek olarak, özüt HCT116 hücre migrasyon seviyesini önemli ölçüde engelledi. U. longissima Ach. etanol özütü anti-QS etkisine (opak bölge 10-12 mm) ek olarak, mikrobiyota da yoğun olan Escherichia coli bakterisinin biyofilm oluşumunu %80-93 oranında azalttı. Sonuç: Sonuç olarak, U. longissima Ach. etanol ekstresinin kolon kanseri hücreleri üzerindeki önemli antikanser ve antibiyofilm etkilerinin, in vivo düzeyde yapılan detaylı çalışmalarla doğrulanmasının ardından konvansiyonel kemoterapötiklere tamamlayıcı olarak umut verici olabileceği düşünülmektedir.

Objective: The aim of this study was to evaluate the oxidant and antioxidant capacities, anti-quorum detection (QS) and antibiofilm activities of ethanol extracts obtained from Prunella vulgaris, Teucrium chamaedrys subsp. chamaedrys and Thymus longicaulis subsp. longicaulis. Materials and Methods: Antibiofilm activities were evaluated using the microplate method against a biofilm-forming Escherichia coli reporter strain. Anti-QS activities were evaluated qualitatively using the well diffusion method with Chromobacterium violaceum ATCC 12472 as a biosensor. Total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI) were measured using commercial kits. Results: All three plant extracts showed strong biofilm inhibition. T. chamaedrys subsp. chamaedrys showed the highest antibiofilm activity with 94.07% inhibition at 12.5 µg/mL. In the anti-QS screening, T. longicaulis subsp. longicaulis extract showed the largest violacein inhibition zone (21.67±3.51 mm) at 75 mg/mL. This extract also exhibited the most favorable oxidative profile with the highest TAS and lowest OSI values among the tested samples. Conclusion: Ethanol extracts of the tested medicinal plants, especially T. longicaulis subsp. longicaulis, have significant antibiofilm, anti-QS and antioxidant activities. The findings indicate the potential of the extracts as natural agent sources to control the virulence properties of pathogens.

In this study, the ethanolic crude extracts obtained from the macrofungus Suillus collinitus (Fr.) O. Kuntze (Suillaceae, Bolatales) were investigated for their antifungal activities against dermatophytes such as the isolates Microsporum gypseum, Trichophyton rubrum and Epidermophyton floccosum by the agar well diffusion method as well as tube dilution method. The ethanol extracts have a strong effect with mean values zone of inhibition at different concentrations and a wide zone of inhibition was determined at 1500 mg/mL (20.8 mm) for M. gypseum, (18.2 mm) for T. rubrum and (16.8 mm) for E. floccosum. MIC of M. gyspseum at 50 µg/mL, MIC of T. rubrum at 60 µg/mL and E. floccosum at 70 µg/mL were observed, respectively. Terbinafine as the comparison antifungal agent gave MIC values between 10 µg/mL for E. floccosum and T. rubrum and 20 µg/mL for M. gypseum. These findings against dermatophytes support our observations regarding the use of this macrofungus among the public. Besides, the findings of this screening study are a preliminary step to further pharmaceutical researches on the relevant macrofungus in the future.

Aim: This study aims to elucidate both the anti-virulence and antimicrobial effects of ethanol extracts from Hypericum calycinum L. and Parietaria officinalis L. Material and Methods: Antimicrobial activity was evaluated using the well diffusion method against five bacteria and two yeast isolates involved in human urinary tract infections (UTIs). The potential of the extracts to inhibit quorum sensing (QS), was assessed using the biosensor strain Chromobacterium violaceum ATCC 12472. Additionally, the antibiofilm activities were investigated using a microplate biofilm assay on Escherichia coli and Pseudomonas aeruginosa. Results: H. calycinum exhibited the highest inhibitory effect at a concentration of 100 mg/mL against Candida albicans with an inhibition zone of 24.5±0.71 mm, while P. officinalis showed its highest effect at the same concentration against E. coli with an inhibition zone of 15.5±0.71 mm. Overall, H. calycinum demonstrated stronger antimicrobial activity compared to P. officinalis. Both plant extracts inhibited QS at similar levels, with inhibition zones ranging between 10-12 mm. The antibiofilm effect varied depending on the bacterial species, but notably, P. officinalis extract exhibited over 80% antibiofilm efficacy against E. coli at all concentrations. Conclusion: This study demonstrates that H. calycinum L. and P. officinalis L. are potent antimicrobial agents against UTI pathogens. While their anti-QS efficacy is not exceptional, the significant inhibition of E. coli biofilm formation underscores their potential as formidable agents. Designed as a fundamental study, it highlights the promising antimicrobial properties of these plant extracts and marks the first investigation into their capabilities as QS and biofilm-preventive agents.

Bacteria can coordinate biofilm formation through antiquorum sensing and create a more effective defense mechanism. Therefore, strategies that inhibit biofilm formation and target the antiquorum sensing mechanism are needed to combat antibiotic resistance. This study was conducted to determine the antibiofilm and antiquorum sensing (anti-QS) effect of essential oils (EOs) obtained from Calendula officinalis L., Hypericum perforatum L. and Trachystemon orientalis (L.) G. Don. and also to calculate oxidative stress indices (OSI) by analysing oxidant and antioxidant capacity. Antibiofilm capacities of EOs against Escherichia coli were investigated by microplate method. Anti-QS activities were evaluated with the agar well diffusion test. The oxidant capacities of plant EOs, whose antioxidant value was determined with the Total Antioxidant Status kit (TAS), were also examined with the Total Oxidant Status kit (TOS), and the OSI were calculated from the ratio of the two. EOs of all three plants have strong antibiofilm and anti-QS effects. T. orientalis, which has 19 mm+ anti-QS effect, shows 93.11% biofilm inhibition effect and draws attention together with the other two plants used pharmacologically. EOs with low OSI levels are expected to have high phytotherapeutic efficacy. As expected, the EOs used are considered important components for their capacity to inhibit biofilm formation and the QS mechanism. This study constitutes the first step in using EOs as alternative agents for strategies that prevent the anti-QS mechanism and biofilm formation.

Bacteria act through a communication mechanism called quorum sensing (QS) to control pathogenicity. Biofilm formation is a process supported by the QS mechanism and is known to act a part in antibiotic resistance. In this study, antimicrobial, anti-QS and antibiofilm capacities of ethanol extracts obtained from Lamium galeobdolon (L.) L. and Lamium purpureum L. plants were determined. The antimicrobial activity of plant extracts was evaluated by well diffusion assay against various hospital isolates. The extracts have antimicrobial effects against all bacteria and yeasts. The 27.5 ± 0.71 mm inhibitory effect of L. purpureum against Candida guilliermondii yeast at a dose of 100 mg/mL is remarkable. The anti-QS potential of the extracts was evaluated by a well diffusion assay based upon violacein pigment inhibition. L. purpureum extract showed a higher level of anti-QS effect against Chromobacterium violaceum ATCC 12472 biosensor strain. Antibiofilm capacity against biofilm-forming Escherichia coli isolate was determined by the crystal violet staining method. L. purpureum extract showed an inhibitory effect of 89.66% against E.coli biofilm at the highest dose. Both plants have been shown to have anti-pathogenic properties. However, it can be said that the L.purpureum plant is a more highly anti-pathogenic plant compared to L. galeobdolon.

Bee products have been used for their therapeutic properties by different civilizations throughout the ages. The antimicrobial activity of bee products without causing the development of resistance...

The current study aimed to evaluate Lamium purpureum L. in terms of its chemical composition and the potential of its essential oil for anticancer activity. The profiling analysis of its chemical composition was carried out via GC-MS. For this purpose, the ethanol extract was subjected to GC-MS analysis to determine chemical compounds. To obtain essential oil, steam distillation of the whole plant (aerial, leaf, stem) was carried out in a Clevenger apparatus. The anticancer activitiy was determined via MTT assay. We observed that the maximum cell death was 14% at 50 μg/mL concentration. As a result of GC-MS analysis, palmitic acid, 7-tetradecenal, octadecadienoic acid, acetic acid, ethyl 9,12,15-octadecatrienoate, hexatriacontane, stearate and benzyl benzoate were identified as major components. We determined that the essential oil of L. purpureum L. had essential compounds which showed cytotoxic activities.