Ilieva Iliyana, Ohgami Kazuhiro, Shiratori Kenji, Koyama Yoshikazu, Yoshida Kazuhiko, Kase Satoru, Kitamei Hirokuni, Takemoto Yuko, Yazawa Kazunaga, Ohno Shigeaki
Department of Ophthalmology and Visual Sciences, Hokkaido University Graduate School of Medicine, North 15, West 7, Kita-ku, Sapporo 060-8638, Japan.
Exp Eye Res. 2004 Aug;79(2):181-7. doi: 10.1016/j.exer.2004.03.009.
Ginkgo biloba extract (GBE) contains many different flavone glycosides and terpenoides. Several previous studies have demonstrated that GBE exhibits a wide variety of biological activities, including an antioxidant action, on which we focused our attention. The aim of the present study was to investigate the efficacy of GBE on endotoxin induced uveitis in rats. The anti-inflammatory potency of GBE in vivo was compared with that of prednisolone. In addition, we also investigated nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor-alpha (TNF-alpha) and the expression of iNOS in a mouse macrophage cell line (RAW 264.7) treated with GBE in vitro to clarify the anti-inflammatory effect.
EIU was induced in male Lewis rats by a footpad injection of lipopolysaccharide (LPS). Immediately after the LPS inoculation, either 1, 10 or 100 microg of GBE were injected intravenously. 24hr later, the aqueous humor was collected from both eyes, and the number of infiltrating cells, protein concentration and NO level in the aqueous humor was determined. The RAW 264.7 cells were pretreated with various concentrations of GBE for 24hr and subsequently incubated with LPS for 24hr. Levels of NO, PGE2 and TNF-alpha were determined by enzyme-linked immunosorbent assay. The expression of iNOS protein was analyzed by Western blotting method.
GBE treatment in vivo decreased the concentrations of protein and NO in the aqueous humor of EIU rats. The anti-inflammatory effect of 1 mg GBE was as strong as that of same dose prednisolone. It also significantly reduced the concentration of PGE2, TNF-alpha and NO production in the medium of RAW 264.7 cells compared to that of the LPS group in vitro. The expression of iNOS protein in the 1000 microg ml(-1) of GBE treated cells decreased significantly.
The present results indicate GBE suppresses the inflammation of EIU by blocking the iNOS protein expression and its anti-inflammatory effect on eye is comparable with the effect of prednisolone used in similar doses.
银杏叶提取物（GBE）含有多种不同的黄酮苷和萜类化合物。先前的几项研究表明，GBE具有多种生物活性，包括抗氧化作用，我们将注意力集中于此。本研究的目的是探讨GBE对大鼠内毒素诱导性葡萄膜炎的疗效。将GBE在体内的抗炎效力与泼尼松龙进行比较。此外，我们还研究了一氧化氮（NO）、前列腺素E2（PGE2）、肿瘤坏死因子-α（TNF-α）以及GBE体外处理的小鼠巨噬细胞系（RAW 264.7）中诱导型一氧化氮合酶（iNOS）的表达，以阐明其抗炎作用。
通过足垫注射脂多糖（LPS）诱导雄性Lewis大鼠发生实验性自身免疫性葡萄膜炎（EIU）。在接种LPS后立即静脉注射1、10或100微克GBE。24小时后，从双眼收集房水，测定房水中浸润细胞数量、蛋白质浓度和NO水平。将RAW 264.7细胞用不同浓度的GBE预处理24小时，随后与LPS一起孵育24小时。通过酶联免疫吸附测定法测定NO、PGE2和TNF-α水平。通过蛋白质印迹法分析iNOS蛋白的表达。
体内GBE治疗降低了EIU大鼠房水中蛋白质和NO的浓度。1毫克GBE的抗炎作用与相同剂量泼尼松龙的抗炎作用一样强。与体外LPS组相比，它还显著降低了RAW 264.7细胞培养基中PGE2、TNF-α的浓度和NO的产生。在1000微克/毫升GBE处理的细胞中，iNOS蛋白的表达显著降低。
目前的结果表明，GBE通过阻断iNOS蛋白表达抑制EIU的炎症，其对眼睛的抗炎作用与相同剂量泼尼松龙的作用相当。
