Department of Chemical Sciences, Faculty of Science Olabisi Onabanjo University, Ago-Iwoye, Nigeria.
J Ethnopharmacol. 2013 Apr 19;146(3):811-4. doi: 10.1016/j.jep.2013.02.007. Epub 2013 Feb 17.
Anthocleista djalonensis (A. Chev) and Anthocleista vogelii Planch are plants being used in West Africa traditionally to treat various diseases such as malaria, hernia, hypertension, stomach aches, hemorrhoids, syphilis, and diabetes. Diabetes causes about 5% of all deaths globally each year. Chemotherapeutic agents such as biguanides, sulfonylureas, and thiozolidinediones are available for the treatment of diabetes, however, they have undesirable side effects. The need for newer, more effective and less toxic drugs is imperative and the biodiversity of Nigeria has a high potential for drug discovery based on plants used in the ethnomedicine.
To investigate the leaves, stem bark and roots of these plants for their probable alpha-amylase inhibitory activities and establish their anti-diabetic activities. The overall goal is do bioassay-guided fractionation and isolation of active anti-diabetic compounds.
Powdered samples (leaves, stem bark and roots) macerated with 80% aqueous methanol were evaluated in vitro using alpha-amylase inhibitory assay while in vivo investigations were carried out on hyperglycemic rats. Diabetes was induced in albino rats by an intraperitoneal injection of alloxan monohydrate (80mg/kg). Plant extracts (1g/kg) were given orally for 7 days, while blood glucose levels were monitored using a one touch glucometer. The crude methanol extracts found to be most active were further partitioned into hexane and ethyl acetate fractions which were also tested in vivo on the diabetic animals.
The leaves and stem bark crude methanol extracts of Anthocleista djalonensis gave comparable α-amylase inhibition of 73.66% and 72.90%, respectively which were quite higher than the 38.93% and 22.90% of the same plant parts given by Anthocleista vogelii. The crude stem bark extract of Anthocleista djalonensis exhibited significant peak blood glucose reduction on day 6 (72.59%, p<0.05) which was higher than the leaves or roots which gave 45.73% and 47.46% (p<0.05), respectively The stem bark ethyl acetate fraction of Anthocleista djalonensis gave reduction in blood glucose level of 60.86% (p<0.05).
From our results, the leaves, stem bark and whole root of both plants exhibited α-amylase inhibitory activities with Anthocleista djalonensis also showing good anti-diabetic activities in vivo indicating that they contain active principles for the management of diabetes. There is justification for the use of the plants traditionally to manage diabetes.
Anthocleista djalonensis（A. Chev）和Anthocleista vogelii Planch 是西非传统上用于治疗各种疾病的植物，如疟疾、疝气、高血压、胃痛、痔疮、梅毒和糖尿病。糖尿病每年导致全球约 5%的死亡。二甲双胍、磺酰脲类和噻唑烷二酮类等化学治疗剂可用于治疗糖尿病，但它们有不良的副作用。需要更有效、更安全的药物，而尼日利亚的生物多样性具有基于传统医学中使用的植物发现新药的巨大潜力。
研究这些植物的叶子、茎皮和根的可能的α-淀粉酶抑制活性，并确定其抗糖尿病活性。总体目标是进行基于生物活性的分离和分离活性抗糖尿病化合物。
用 80%甲醇的粉末样品（叶子、茎皮和根）进行体外α-淀粉酶抑制活性评估，而体内研究则在高血糖大鼠上进行。用一水合阿脲（80mg/kg）腹腔注射诱导白化大鼠糖尿病。植物提取物（1g/kg）口服给予 7 天，同时使用 One Touch 血糖仪监测血糖水平。发现最活跃的甲醇粗提取物进一步分为正己烷和乙酸乙酯部分，也在糖尿病动物体内进行了测试。
Anthocleista djalonensis 的叶子和茎皮甲醇粗提取物的α-淀粉酶抑制率分别为 73.66%和 72.90%，明显高于 Anthocleista vogelii 相同植物部分的 38.93%和 22.90%。Anthocleista djalonensis 的茎皮甲醇粗提取物在第 6 天显示出显著的峰值血糖降低（72.59%，p<0.05），高于叶子或根的 45.73%和 47.46%（p<0.05）。Anthocleista djalonensis 的茎皮乙酸乙酯部分可使血糖水平降低 60.86%（p<0.05）。
根据我们的结果，两种植物的叶子、茎皮和整个根都表现出α-淀粉酶抑制活性，而 Anthocleista djalonensis 在体内也表现出良好的抗糖尿病活性，表明它们含有用于管理糖尿病的活性成分。传统上使用这些植物来治疗糖尿病是有道理的。
