The present study was aimed to investigate a protective effect of polysaccharide rich fraction from Eulophia herbacea Lindl. tubers against methotrexate (MTX) induced liver damage in rats. The polysaccharide-rich extract fraction of E. herbacea (PEEH) was isolated from tubers by maceration and then evaluated for its hepatoprotective effect on MTX induced liver damage in rats through measurement of the liver enzymes function and the levels of proinflammatory cytokines and antioxidants. A group of 30 Wistar albino rats were randomly selected and divided into five groups, each containing six rats. Normal control group received saline, negative control group received MTX (20 mg/kg, i.p.) at a single dose, and test groups received MTX (20 mg/kg, i.p.) followed by the PEEH fraction at 100 and 200 mg/kg (p.o.) for four days. Silymarin (100 mg/kg, p.o.) was used as standard for comparison. Biochemical analysis and histological examinations of liver were performed on the fifth day. The PEEH fraction contains 26.71 mg glucomannan per gram of tubers, as estimated by HPTLC method. Results of this study confirmed that PEEH treatment led to significantly reduced (P ≤ 0.01) level of liver enzymes (ALP, ALT and AST) that improved the liver function. PEEH was also able to improve the activity of liver antioxidants (GSH, SOD and CAT), decrease lipid peroxidation, and restore it to a normal level. This was an indication of decreasing oxidative stress caused by MTX. PEEH treatment (100 and 200 mg/kg) significantly reduced the level of proinflammatory cytokines (P ≤ 0.01) in dose-dependent manner. These effects were confirmed by histological examination of the liver. In conclusion, polysaccharide rich fraction of E. herbacea tubers showed liver protection effect through reduction of the oxidative stress and produced an anti-inflammatory action.

本研究旨在研究来自Eulophia herbacea Lindl 的富含多糖组分的保护作用。抗甲氨蝶呤 (MTX) 的块茎诱导大鼠肝损伤。丰富的多糖提取物馏分E. herbacea(PEEH) 通过浸渍从块茎中分离出来，然后通过测量肝酶功能以及促炎细胞因子和抗氧化剂的水平来评估其对 MTX 诱导的大鼠肝损伤的保肝作用。随机选取 30 只 Wistar 白化大鼠，分为 5 组，每组 6 只。正常对照组接受生理盐水，阴性对照组接受单次剂量的 MTX（20 mg/kg，ip），测试组接受 MTX（20 mg/kg，ip），然后是 100 和 200 mg/kg 的 PEEH 部分（ po）四天。水飞蓟素 (100 mg/kg, po) 用作比较标准。第五天进行肝脏生化分析和组织学检查。根据 HPTLC 方法估计，PEEH 级分包含 26.71 mg 葡甘露聚糖/克块茎。P ≤ 0.01) 改善肝功能的肝酶（ALP、ALT 和 AST）水平。PEEH 还能够提高肝脏抗氧化剂（GSH、SOD 和 CAT）的活性，减少脂质过氧化，并将其恢复到正常水平。这表明由 MTX 引起的氧化应激减少。PEEH 治疗（100 和 200 mg/kg ）以剂量依赖性方式显着降低促炎细胞因子的水平（P ≤ 0.01）。这些作用通过肝脏的组织学检查得到证实。总之，草本植物块茎中富含多糖的部分通过减少氧化应激显示出肝脏保护作用，并产生抗炎作用。