Zakaria Zainul Amiruddin, Balan Tavamani, Mamat Siti Syariah, Mohtarrudin Norhafizah, Kek Teh Lay, Salleh Mohd Zaki
Halal Product Research Institute, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia.
Integrative Pharmacogenomics Institute (iPROMISE), Faculty of Pharmacy, Universiti Teknologi MARA, Shah Alam, Selangor, Malaysia.
BMC Complement Altern Med. 2015 Apr 28;15:135. doi: 10.1186/s12906-015-0638-z.
Melastoma malabathricum L. (Melastomaceae) is a small shrub with various medicinal uses. The present study was carried out to determine the gastroprotective mechanisms of methanol extract of M. malabathricum leaves (MEMM) in rats.
The extract's mechanisms of gastroprotection (50, 250, 500 mg/kg) were studied using the pylorus-ligation in rat model wherein volume, pH, free and total acidity of gastric juice, and gastric wall mucus content were determined. The involvement of endogenous nitric oxide (NO) and sulfhydryl (SH) compounds in the gastroprotective effect of MEMM were also measured. MEMM was subjected to the antioxidant, anti-inflammatory and phytochemical analysis and HPLC profiling.
MEMM contained various phyto-constituents with quercitrin being identified as part of them. MEMM and quercitrin: i) significantly (p < 0.05) reduced the volume and acidity of gastric juice while increasing the pH and gastric wall mucus content.; ii) significantly (p < 0.05) increased the level of SOD, GTP and GTR while significantly (p < 0.05) reduced the level of CAT, MPO and TBARS activities.; iii) exerted gastroprotective activity when assessed using the ethanol-induced gastric ulcer assay, which was reversed by N(G)-nitro-L-arginine methyl esters (L-NAME; an inhibitor of NO synthase) and N-ethylmaleimide (NEM; a sulfhydryl (SH) blocker). MEMM inhibited the lipoxygenase (LOX) and xanthine oxidase (XO) activities with the highest affinity for the former while quercitrin showed high affinity for XO activity.
MEMM exhibited a gastroprotective activity due partly to the presence of quercitrin, its antioxidant and anti-inflammatory activities, and via the modulation of NO and SH groups.
毛稔（野牡丹科）是一种具有多种药用价值的小灌木。本研究旨在确定毛稔叶甲醇提取物（MEMM）对大鼠的胃保护机制。
采用大鼠幽门结扎模型研究提取物（50、250、500mg/kg）的胃保护机制，测定胃液的体积、pH值、游离酸度和总酸度以及胃壁黏液含量。还测定了内源性一氧化氮（NO）和巯基（SH）化合物在MEMM胃保护作用中的参与情况。对MEMM进行了抗氧化、抗炎和植物化学分析以及高效液相色谱分析。
MEMM含有多种植物成分，其中槲皮苷被鉴定为其中一部分。MEMM和槲皮苷：i）显著（p<0.05）降低了胃液的体积和酸度，同时提高了pH值和胃壁黏液含量；ii）显著（p<0.05）提高了超氧化物歧化酶（SOD）、谷胱甘肽转移酶（GTP）和谷胱甘肽还原酶（GTR）的水平，同时显著（p<0.05）降低了过氧化氢酶（CAT）、髓过氧化物酶（MPO）和硫代巴比妥酸反应物（TBARS）的活性；iii）在乙醇诱导的胃溃疡试验中评估时表现出胃保护活性，该活性被N（G）-硝基-L-精氨酸甲酯（L-NAME；一氧化氮合酶抑制剂）和N-乙基马来酰胺（NEM；巯基（SH）阻断剂）逆转。MEMM抑制脂氧合酶（LOX）和黄嘌呤氧化酶（XO）的活性，对前者具有最高亲和力，而槲皮苷对XO活性表现出高亲和力。
MEMM表现出胃保护活性，部分原因是其含有槲皮苷、具有抗氧化和抗炎活性以及对NO和SH基团的调节作用。
