BACKGROUND The Cycas circinalis(C. circinalis) leaves are used to treat diabetes mellitus in local medicinal system without any scientifically proved information on their medicinal potential and phytochemicals. In current study the total phenolic contents, total flavonoid contents, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging and inhibitory effects on α-glucosidase and α-amylase were determined for optimized hydroethanolic leaf extracts. Secondary metabolites were identified using ultra-high performance liquid chromatography-quadrupole time of flight-mass spectrometry (UHPLC-QTOF-MS/MS). In vivo studies on diabetic albino mice were also carried out to evaluate the impact of most active extract on their blood glucose levels. RESULTS The 60% ethanolic extract showed highest extract yield, total phenolic and flavonoid contents of 209.70 ± 0.20 g kg-1 , 154.24 ± 3.28 mg gallic acid equivalent and 78.52 ± 1.65 mg rutin equivalent per gram dried extract, respectively and exhibited the maximum DPPH scavenging with IC50 value of 59.68 ± 2.82 μg/mL. The IC50 values inhibition of α-glucosidase (58.42 ± 2.22 μg/mL)and α-amylase (74.11 ± 1.70 μg/mL) were also significant for 60% ethanolic extract. The untargeted UHPLC-QTOF-MS/MS based metabolite profiling confirmed the presence of Iridoid glucoside, gibberllins A4, O-beta-D-glucosyl-4-hydroxy-cinnamate, 3-methoxy-2-phyenyl-4-H-furo (2,3-h) chromen-4-one, kaempferol, withaferin A, amentoflavone, quercitin-3-O-(6″-malonyl glucoside), ellagic acid and gallic acid. Plant extract at dose of 500 mg/kg body weight of reduced the blood glucose level to considerable extent and also improved lipid profile of diabetic mice after 28 days trial. CONCLUSION The findings revealed the medicinal potential of Cycas circinalis leaves to treat diabetes mellitus and provided the nutraceutical leads for functional food development. This article is protected by copyright. All rights reserved.

中文翻译：

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优化苏铁叶提取物的多酚指纹图谱和降血糖特性

背景 苏铁（C. circinalis）叶在当地药用系统中用于治疗糖尿病，但没有任何关于其药用潜力和植物化学物质的科学证明信息。在目前的研究中，确定了优化的水乙醇叶提取物的总酚含量、总黄酮含量、2,2-二苯基-1-苦基肼 (DPPH) 清除和对 α-葡萄糖苷酶和 α-淀粉酶的抑制作用。使用超高效液相色谱-四极杆飞行时间质谱 (UHPLC-QTOF-MS/MS) 鉴定次级代谢物。还对糖尿病白化小鼠进行了体内研究，以评估大多数活性提取物对其血糖水平的影响。结果 60%乙醇提取物的提取率最高，总酚和黄酮含量为209.70±0。每克干提取物分别为 20 g kg-1、154.24 ± 3.28 mg 没食子酸当量和 78.52 ± 1.65 mg 芦丁当量，并表现出最大的 DPPH 清除，IC50 值为 59.68 ± 2.82 μg/mL。对于 60% 乙醇提取物，抑制 α-葡萄糖苷酶 (58.42 ± 2.22 μg/mL) 和 α-淀粉酶 (74.11 ± 1.70 μg/mL) 的 IC50 值也很显着。基于非靶向 UHPLC-QTOF-MS/MS 的代谢物分析证实了环烯醚萜苷、赤霉素 A4、O-β-D-葡萄糖基-4-羟基-肉桂酸酯、3-甲氧基-2-苯基-4-H-呋喃的存在（ 2,3-h) chromen-4-one、山奈酚、睡茄素 A、amentoflavone、槲皮素-3-O-(6″-丙二酰葡萄糖苷)、鞣花酸和没食子酸。28 天试验后，500 毫克/公斤体重剂量的植物提取物可在相当程度上降低血糖水平，并改善糖尿病小鼠的血脂状况。结论 研究结果揭示了苏铁叶治疗糖尿病的药用潜力，并为功能性食品的开发提供了营养药物的先导。本文受版权保护。版权所有。