Anti-hyperglycemic Effect of Bilberry, Blackberry and Mulberry Ultrasonic Extracts on Diabetic Rats
Abstract
Small fruits like bilberry, blackberry and mulberry are rich sources of anthocyanins and other phenols, compounds with a certified antioxidant activity and spectacular effects in some chronic diseases. Romanian bilberry, blackberry and mulberry extracts were tested as anti-hyperglycemic agents on diabetic rats. Anthocyanins extraction was carried out with 80 % acidified ethanol in ultrasonically conditions at 23 ± 2 °C and 40 kHz. Monomeric anthocyanins content was determined by pH differential method and varied between 1200 and 2800 mg/L. The analyses of anthocyanins were achieved using high performance liquid chromatography and mass spectrometry. Phenolics content was determined by Folin-Ciocalteu procedure and values varied between 2320 and 4250 mg/L gallic acid. Antioxidant activities of extracts were estimated by DPPH scavenging method and the values varied between 8 and 16 miliequivalents Trolox. In order to evaluate the toxicology of the extracts, the heavy metals concentration and pesticides content were analyzed. The extracts were administrated to diabetic rats in drinking water for five weeks. The administration of bilberry extract offered no satisfactory results. Treatment with blackberry extract determined a significant decrease of glucose level from 360 to about 270 mg/dL (p < 0.05). The mulberry extract administration determined a significant decrease of glucose level from 252 mg/dL at the start day to 155 mg/dL at the final of experiment (p < 0.05).
小的果实如越橘、黑莓和桑葚是花青素和其他酚类物质的丰富来源，这些化合物具有经认证的抗氧化活性，对一些慢性疾病有惊人的效果。研究了罗马尼亚越桔、黑莓和桑椹提取物对糖尿病大鼠的降血糖作用。用80%酸化乙醇在23±2℃、40 kHz超声条件下提取花青素。采用pH差值法测定单体花青素含量，在1200 ~ 2800 mg/L之间。花青素的分析采用高效液相色谱和质谱联用技术。用Folin-Ciocalteu法测定酚类物质的含量，值在2320 ~ 4250 mg/L没食子酸之间。采用DPPH清除法测定提取物的抗氧化活性，其值在8 ~ 16个特洛克斯当量之间。为了评价提取物的毒理作用，对其进行了重金属浓度和农药含量分析。糖尿病大鼠饮水给药5周。越桔提取物的给药效果不理想。经黑莓提取物处理后，血糖水平显著降低，从360毫克/分升降至270毫克/分升(p < 0.05)。桑椹提取物显著降低了葡萄糖水平，从实验开始时的252 mg/dL降低到实验结束时的155 mg/dL (p <0.05)。
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