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Bu çalışmada, Ficus carica yapraklarına ait su ve metanol ekstrelerinin diyabet ve Alzheimer hastalığı ile ilişkili enzimlerin inhibisyonu üzerine etkisinin araştırılması amaçlanmıştır. Ayrıca, ekstrelere ait biyoaktif bileşenler, antikanser, antioksidan ve antimikrobiyal etkiler de araştırılmıştır. Gereç ve Yöntemler: Ekstrelerdeki biyoaktif bileşikler gaz kromatografisi-kütle spektrometresi metodu ile belirlenmiştir. Antioksidan aktivite, 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6 sulphonic acid) (ABTS) radikal süpürücü, toplam fenol ve flavonoid içeriği, ferrik indirgeme gücü ve demir şelasyon yöntemleriyle değerlendirilmiştir. Antikanser, antikolinesteraz ve antimikrobiyal etkinlikler ise sırasıyla XTT yöntemi, Ellman yöntemi ve mikrodilüsyon tekniği yöntemi ile belirlenmiştir. Bulgular: Elde ettiğimiz sonuçlar su ve metanol ekstreleri arasında kimyasal bileşim açısından farklılık olduğunu ve her iki ekstrenin de güçlü antioksidan aktiviteye sahip olduğunu göstermiştir. Benzer şekilde, her iki ekstrede güçlü α-glikozidaz ve α-amilaz aktivite gösterirken, su ekstresi metanole göre daha güçlü asetilkolinesteraz ve butirilkolinesteraz inhibisyon etkiye sahiptir. F. carica metanol ekstresi MDA-MB-231 hücreleri üzerinde güçlü antikanser etki, Escherichia coli ve Staphylococcus aureus'e karşı ise orta düzeyde antimikrobiyal etki göstermiştir. Sonuç: Bulgularımız, F. carica yapraklarının kanser, diyabet ve Alzheimer hastalığında umut verici bir terapötik ajan geliştirmek için değerli bir kaynak olabileceğini düşündürmektedir.

Abstract:The Stevia rebaudiana (Bert.) Bertoni is a perennial herbaceous plant and belongs to family of Asteraceae (Compositae). The contents of S. rebaudiana (Bert.) Bertoni consist mainly non-caloric stevioside and rebaudioside A sweeteners. Low seed germination is an important problem in stevia cultivation. Therefore in this study, the effects of light and temperature on germination performance of stevia seeds were studied. Stevia rebaudiana seeds were treated with two lights (light/darkness) and four different temperatures (15 ºC, 20 ºC, 25 ºC, 30 ºC). For each treatment, 50 seeds were counted and placed into petri dishes. Experiments were conducted as a randomized complete design method with three replicates. Germination was started within 6 to 10 days depending on the treatments. The highest seed germination rate (71%) was observed in darkness/25 ºC temperature and followed by darkness/20 ºC (68%) and light/25 ºC (67%). On the other hand, the lowest seed germination rate (31%) was obtained from 15 ºC in both light and dark conditions and followed by darkness/30 ºC (43%) and light/30 ºC (49%). The results showed that lower (15 ºC) and higher (30 ºC) temperatures significantly decreased the germination rates of stevia independently from the light treatments.

In this study, it was investigated the growth of stevia (Stevia rebaudiana Bertoni) under various wavelengths of LED lamp (Light Emitting Diodes), which can emit daylight (cool white; 400-700 nm), red (620-630 nm) and blue (465-485 nm) wavelengths of the light in the electromagnetic spectrum. In all applications, quantity of PAR (photosynthetically active radiation) was adjusted as 150 µmol.m -2 s -1 . Study had maintained in plant breeding cabin 16 hours light and 8 hours dark environment. Results demonstrated that while the highest plant height was determined in the "30% blue light+ 70% red light" application, the highest stem length was found in the "50% blue light + 50% red light" application. In addition, the number of the stems reached the highest value in the "70% blue light + 30% red light" application. Consequently, a correlation was observed between negative "a" value and the amount of chlorophyll. Because of the hereby obtained results, comparing to other applications, the "50% blue light + 50% red light" was found as the best light application to obtain optimum yield values of stevia.

In this study, the efficiency of the different nitrogen doses (0, 5, 10, 15 and 20 kg ha-1) on biological activity levels (antioxidant and antimicrobial activity) of Stevia rebaudiana Bert. was investigated. In addition, methanol extracts were obtained by maceration method from different doses of fertilizer applied stevia. The components in methanol extracts of plants were determined by gas chromatography-mass spectrometry (GC-MS) method. Antimicrobial activities of stevia extracts were investigated by microdilution method. The antioxidant activity evaluated by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ferric thiocyanate (FTC), thiobarbituric acid (TBA), reducing power, total phenol content (TPC), and total flavonoid content (TFC) methods. According to the results, the fertilizer doses effects on antimicrobial activity of stevia were not made much difference. But in antioxidant activity, there were some variations in the activity-dependent on fertilizer amount.

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