지실의 항산화, 항당뇨합병증 및 항균효과

Abstract

Abstract

The Poncirus Fructus (PF) is a dride immature fruit of Poncirus trifoliate (L.) Ref., which was distributed throughout Asia, including China and Korea. PF has been used for stomachache, vomiting, nausea, abdominal distension, and swelling of testis in the Oriental Medicine. The PF contains high amounts of a various flavonoids such as poncirin, naringin, hesperidin, neohesperidin, rhoifolin,poncimarin and poncitrin. And it exhibit a wide range of biological activities; they have anti-inflammatory, anti-allergic and anti-virus, antiplatelet and cancer chemopreventive properties. It is well known that the beneficial effects on health of flavonoids are due to their antioxidant and phytoestrogenic properties. Still, further study is needed to investigate bio-active components of Poncirus Fructus with a large quantity of flavonoid and its antioxidant activity in a variety of experimental conditions. In order to investigate antioxidant effects of methanol extracts of Poncirus Fructus and fractions extracted by systematic fractionation using DPPH radical scavenging activity, ABTS radical scavenging activity, inhibitory activity of generation of reactive oxygen species (ROS), peroxynitrite scavenging activity, ACE inhibitory activity, and consider their effects on diabetic complications, therefore, advanced glycation end products (AGEs) formation inhibitory activity and lens aldose reductase inhibitory activity were conducted through in-vitro methods. Then, Poncirus Fructus antibacterial effects were examined. In Poncirus Fructus DPPH radical scavenging activity, EtOAc fraction showed the largest scavenging activity at 240.78 μg/ml, of various extracts and fractions and showed weaker scavenging activity than L-ascorbic acid (IC50 value:10.30 μg/ml). In Poncirus Fructus ABTS radical scavenging activity, EtOAc fraction showed the largest scavenging activity at 29.70 μg/ml, of various extracts and fractions and showed weaker scavenging activity than L-ascorbic acid (IC50 value: 5.43 μg/ml) and Trolox (IC50 value: 3.33 μg/ml). In relation to ONOO-scavenging activityIC50 values (μg/ml) of MeOH extract and fraction of Poncirus Fructus, EtOAc fraction had the largest scavenging activity, followed by H2O fraction, n-BuOH fraction, CH2Cl2 fraction and MeOH fraction. Then, a control substance, L-penicillamine displayed 50 percent of ONOO- scavenging activity at 3.69 μg/ml. Seeing that EtOAc fraction showed relatively higher ONOO-scavenging activity at 17.20 μg/ml, although it was lower than a control substance, it is assumed that EtOAc fraction contains more ONOO- scavenging activity substances than other substances and that it is somewhat polar. It’s been reported that ACE is relevant to the occurrence of cells oxidative stress, reactive oxygen species (ROS) and reactive nitrogen species (RNS), and that it increases the incidence of thrombosis caused by platelet aggregation and adhension. Accordingly, Poncirus Fructus EtOAc fraction showed higher ROS and ONOO- scavenging activities, and ACE inhibitory activity than other fractions. When conducting in-vitro experiments to observe advanced glycation end products (AGEs) formation inhibitory activity and lens aldose reducttase inhibitory activity in Poncirus Fructus methanol extracts, and CH2Cl2, EtOAc, n-BuOH and H2O fractions, EtOAc fraction had the strongest advanced glycation end products (AGEs) formation inhibitory activity and lens aldose reducttase inhibitory activity among them. Then, active component of EtOAc fraction with high advanced glycation end products (AGEs)formation inhibitory activity and lens aldose reducttase inhibitory activity was separated using silica gel chromatography. Structure of the separated compound was measured using spectroscopic methodology of 1H-NMR and 13C-NMR and then, β-sitosterol, prunin and poncirin were identified, by comparing them with literature results. MeOH Ex. and CH2Cl2 fr. were found to have antibacterial effects. Judging from these results, it is considered that Poncirus Fructus extracts used in this research are valuable and possible enough to cure diabetic complications as well as a natural antimicrobial, antioxidant and antidiabetic, and thus is enough competitive with the existing natural functional substances.