Ahmed Dildar, Mughal Qaria Mumtaz, Younas Saba, Ikram Muhammad
Department of Chemistry, Forman Christian College (A Chartered University), Ferozpur Road, Lahore, Pakistan.
Pak J Pharm Sci. 2013 May;26(3):553-9.
The present study aimed to establish relationship between urease and alpha-amylase inhibitory activities on the one hand and on the other between anti-enzymatic activities and total phenolic contents of the methanolic extract of roots of Rumex acetosella and its fractions in various solvents. The methanolic extract and its fractions in chloroform, ethyl acetate, n-butanol and water showed remarkable inhibitory activities against both urease and alpha-amylase, there was a close correspondence between urease and alpha-amylase inhibitory activities of the plant samples. The n-butanol fraction which had the highest total phenolic content (252.19 ± 2.32 µg of Gallic Acid Equivalents/mg of dry mass of the sample) showed prominent activity against both urease and alpha-amylase indicating a possible role of phenolics in inhibiting the activities of these enzymes. The samples displayed enzyme inhibitory activities in a dose dependent manner and their effectiveness was comparable with that of the standards, thiourea (for urease) and acarbose (for alpha-amylase). The samples were manifold more effective against urease than alpha-amylase; 2.8 mg/mL of MeOH extract produced about 81% inhibition in alpha-amylase activity, while only 10 µg/mL of the extract was required to create the same inhibition in urease activity. The IC50 values of methanolic, chloroform, ethyl acetate, n-butanolic, aqueous and standard solutions were 1.29, 1.31, 1.90, 1.38, 0.85 and 1.20 (mg/mL) respectively against alpha-amylase and 0.99, 3.89, 1.76, 0.91, 0.85 and 0.97 (μg/mL) respectively against urease. The total phenolic content in MeOH, hexane, chloroform, ethyl acetate, n-butanol and water fractions was 108.88 ± 2.65, 43.70 ± 1.90, 34.44 ± 2.30, 230.71 ± 1.78, 252.19 ± 2.32 and 94.07 ± 2.25 respectively.
本研究旨在一方面建立脲酶和α-淀粉酶抑制活性之间的关系，另一方面建立酸模根甲醇提取物及其不同溶剂级分的抗酶活性与总酚含量之间的关系。甲醇提取物及其氯仿、乙酸乙酯、正丁醇和水级分对脲酶和α-淀粉酶均表现出显著的抑制活性，植物样品的脲酶和α-淀粉酶抑制活性之间存在密切对应关系。总酚含量最高的正丁醇级分（252.19±2.32μg没食子酸当量/mg样品干质量）对脲酶和α-淀粉酶均表现出突出活性，表明酚类物质在抑制这些酶的活性中可能发挥作用。样品呈剂量依赖性地表现出酶抑制活性，其有效性与标准品硫脲（用于脲酶）和阿卡波糖（用于α-淀粉酶）相当。样品对脲酶的有效性比对α-淀粉酶高得多；2.8mg/mL的甲醇提取物对α-淀粉酶活性产生约81%的抑制，而对脲酶活性产生相同抑制仅需10μg/mL的提取物。甲醇、氯仿、乙酸乙酯、正丁醇、水和标准溶液对α-淀粉酶的IC50值分别为1.29、1.31、1.90、1.38、0.85和1.20（mg/mL），对脲酶的IC50值分别为0.99、3.89、1.76、0.91、0.85和0.97（μg/mL）。甲醇、己烷、氯仿、乙酸乙酯、正丁醇和水级分中的总酚含量分别为108.88±2.65、43.70±1.90、34.44±2.30、230.71±1.78、252.19±2.32和94.07±2.25。
