Publication: Populus tremula L.türünden antidiyabetik aktivite yönlendirmeli aktif bileşiklerin izolasyonu
Abstract
Amaç: Diyabet, metabolik bozuklukların neden olduğu, yaşam kalitesini olumsuz yönde etkileyen kronik bir hastalıktır. Bu çalışmanın amacı, Türkiye’de doğal olarak yetişen beş Populus türünden biri olan Populus tremula L. yapraklarını antidiyabetik etkisi açısından in vitro çalışmalarla ilk kez değerlendirmek ve etkiden sorumlu temel bileşiğinin izolasyonunu sağlamaktır. Gereç ve Yöntem: Ekstrelerin/ fraksiyonların antidiyabetik aktiviteleri α-glukozidaz yöntemi ile test edilmiştir. Ayrıca, ekstrakt/ fraksiyonların antioksidan etkileri ABTS/ DPPH radikal süpürme yöntemi ile araştırılmış, toplam flavonoit, fenolik ve triterpen içerikleri sırasıyla AlCl3, Folin Ciocalteu ve vanilin-perklorik asit yöntemleri ile tahmin edilmiştir. Aktif ekstreden madde kromatografik yöntemlerle izole edilmiş, yapısı spektroskopik yöntemlerle aydınlatılmıştır. Bulgular: PTH, 167,20 µg/ mL IC50 değeri ile fraksiyonlar arasından α-glukozidaz enzimine karşı en yüksek antidiyabetik aktiviteyi göstermiştir. PTH, standart akarboz (261,70 µg/ mL) ile karşılaştırıldığında da önemli bir antidiyabetik aktivite göstermiştir. PTH’dan α-glukozidaz inhibitor aktivite yönlendirmeli izolasyonla palmitik asit bileşiği elde edilmiş ve bu bileşiğin de enzime karşı 70,29 µg/ mL IC50 değeri ile güçlü bir aktiviteye sahip olduğu bulunmuştur. Antioksidan aktivite açısından, PTEA (1,74 ve 4,38 µg/ mL) ve PTE (0,99 ve 5,93 µg/ mL) sırasıyla ABTS ve DPPH radikallerine karşı IC50 değerlerine göre önemli etki göstermiştir. En yüksek toplam fenolik içerik PTEA (104,80 mg/ g) ve PTE’de (103,20 mg/ g), en yüksek toplam flavonoit içeriği PTEA’da (93,38 mg/ g) ve en yüksek toplam triterpen içeriği ise PTEA ve PTK (her biri 210,40 mg/ g)’da bulunmuştur. Sonuç: Bu sonuçlar, iyi bir α-glukozidaz inhibitor etki sergileyen PTH’ın etkisinden taşıdığı diğer bileşenlerle birlikte özellikle palmitik asitin sorumlu olabileceğini göstermektedir. Bununla birlikte, bitkinin etkinliğini tam olarak göstermek için α-amilaz inhibitör aktivitesi gibi daha farklı in vitro yöntemlerin yanı sıra streptozotosinle diyabet modeli oluşturulmuş sıçanlarda in vivo çalışmalara ihtiyaç vardır. Ayrıca PTE ile onun fraksiyonu PTEA’nın da önemli bir antioksidan etkiye sahip olduğu ortaya çıkarılmıştır.
Objective: Diabetes is a chronic disease caused by metabolic disorders that negatively affects the quality of life. The aim of this study was to evaluate the antidiabetic effect of Populus tremula L. leaves, one of the five Populus species growing naturally in Türkiye, for the first time by in vitro studies and to isolate the main compound responsible for the effect. Materials and Methods: The antidiabetic activities of the extracts/ fractions were tested by αglucosidase method. In addition, antioxidant effects of the extract/ fractions were investigated by ABTS/ DPPH radical scavenging methods and total flavonoid, phenolic and triterpene contents were estimated by AlCl3, Folin Ciocalteu and vanillin-perchloric acid methods, respectively. The substance was isolated from the active extract by chromatographic methods and its structure was elucidated by spectroscopic methods. Results: PTH with IC50 value of 167.20 µg/ mL showed the highest antidiabetic activity against α-glucosidase enzyme among the fractions. PTH also showed significant antidiabetic activity when compared with standard acarbose (261.70 µg/ mL). Palmitic acid was obtained from PTH by isolation directed at α-glucosidase inhibitory activity and this compound was found to have strong activity against nzim with IC50 value of 70.29 µg/ mL. In terms of antioxidant activity, PTEA (1.74 and 4.38 µg/ mL) and PTE (0.99 and 5.93 µg/ mL) showed significant effect against ABTS and DPPH radicals according to their IC50 values, respectively. The highest totalphenolic content was found in PTEA (104.80 mg/ g) and PTE (103.20 mg/ g), the highest total flavonoid content was found in PTEA (93.38 mg/ g) and the highest total triterpene content was found in PTEA and PTK (210.40 mg/ g each). Conclusion: These results suggest that palmitic acid in particular may be responsible for the effect of PTH, which exhibits a good α-glucosidase inhibitory effect, along with other components it carries. However, more in vitro methods such as α-amylase inhibitory activity as well as in vivo studies in rats modeled with streptozotocin-induced diabetes are needed to fully demonstrate the efficacy of the plant. In addition, PTE and its fraction PTEA were also found to have a significant antioxidant effect.
Objective: Diabetes is a chronic disease caused by metabolic disorders that negatively affects the quality of life. The aim of this study was to evaluate the antidiabetic effect of Populus tremula L. leaves, one of the five Populus species growing naturally in Türkiye, for the first time by in vitro studies and to isolate the main compound responsible for the effect. Materials and Methods: The antidiabetic activities of the extracts/ fractions were tested by αglucosidase method. In addition, antioxidant effects of the extract/ fractions were investigated by ABTS/ DPPH radical scavenging methods and total flavonoid, phenolic and triterpene contents were estimated by AlCl3, Folin Ciocalteu and vanillin-perchloric acid methods, respectively. The substance was isolated from the active extract by chromatographic methods and its structure was elucidated by spectroscopic methods. Results: PTH with IC50 value of 167.20 µg/ mL showed the highest antidiabetic activity against α-glucosidase enzyme among the fractions. PTH also showed significant antidiabetic activity when compared with standard acarbose (261.70 µg/ mL). Palmitic acid was obtained from PTH by isolation directed at α-glucosidase inhibitory activity and this compound was found to have strong activity against nzim with IC50 value of 70.29 µg/ mL. In terms of antioxidant activity, PTEA (1.74 and 4.38 µg/ mL) and PTE (0.99 and 5.93 µg/ mL) showed significant effect against ABTS and DPPH radicals according to their IC50 values, respectively. The highest totalphenolic content was found in PTEA (104.80 mg/ g) and PTE (103.20 mg/ g), the highest total flavonoid content was found in PTEA (93.38 mg/ g) and the highest total triterpene content was found in PTEA and PTK (210.40 mg/ g each). Conclusion: These results suggest that palmitic acid in particular may be responsible for the effect of PTH, which exhibits a good α-glucosidase inhibitory effect, along with other components it carries. However, more in vitro methods such as α-amylase inhibitory activity as well as in vivo studies in rats modeled with streptozotocin-induced diabetes are needed to fully demonstrate the efficacy of the plant. In addition, PTE and its fraction PTEA were also found to have a significant antioxidant effect.