Nazari Mahmood, Hajizadeh Mohammad Reza, Mahmoodi Mehdi, Mirzaei Mohammad Reza, Hassanshahi Gholamhossein
Department of Biochemistry Biophysics & Genetics, Faculty of Medicine, Rafsanjan University of Medical Sciences, Rafsanjan, Iran.
Clin Lab. 2013;59(5-6):497-504. doi: 10.7754/clin.lab.2012.120611.
Many traditional therapies have been proposed as alternative regimens for treatment of diabetes mellitus. The Morus Alba (MA) leaf is a natural therapeutic compound which is shown to have antidiabetic properties. The aim of the present study was to determine whether MA leaf extract is capable of regulating liver enzymes that are involved in glucose metabolism pathways in normal and Streptozotocin (STZ)-induced diabetic rats.
Forty healthy adult male Wistar rats (eight weeks old) weighing about 250 +/- 10 g were taken for this experiment. The rats were divided into 4 groups with 10 rats in each group and treated through a gavage tube for a period of two months as follows: group I: non diabetic control rats with distilled water; group II: non diabetic rats with 1.0 g/kg per day; group III: diabetic control rats with distilled water and group IV: diabetic rats with MA 1.0 g/kg per day. At the end of the 8th week, serum glucose, insulin and hepatic glucokinase activity were measured using standard methods and compared between diabetic and healthy rats. We also assessed the expression of phosphofructokinase-1 enzyme at the level of mRNA, using a Real Time-PCR method.
Findings of the present study demonstrated that MA leaf extract can significantly increase liver glucokinase activity and serum insulin levels in diabetic rats (p < 0.05). It also significantly attenuated the serum glucose level in rats compared to the control groups (p < 0.05). Also, the body weight of diabetic rats was significantly (p < 0.05) decreased as compared to their initial weight. However, the body weights of diabetic rats treated with MA increased in the same way as normal control rats.
The present findings suggest that the antihyperglycemic action of MA is mediated by increasing liver glucokinase activity and serum insulin level. These results are additional, definite evidence supporting MA as traditional medicine for diabetic patients.
许多传统疗法已被提出作为治疗糖尿病的替代方案。桑叶是一种天然治疗化合物，已显示具有抗糖尿病特性。本研究的目的是确定桑叶提取物是否能够调节正常和链脲佐菌素（STZ）诱导的糖尿病大鼠中参与葡萄糖代谢途径的肝酶。
选取40只健康成年雄性Wistar大鼠（8周龄），体重约250±10g用于本实验。将大鼠分为4组，每组10只，通过灌胃管治疗两个月，具体如下：第一组：用蒸馏水的非糖尿病对照大鼠；第二组：每天1.0g/kg的非糖尿病大鼠；第三组：用蒸馏水的糖尿病对照大鼠；第四组：每天1.0g/kg桑叶的糖尿病大鼠。在第8周结束时，使用标准方法测量血清葡萄糖、胰岛素和肝葡萄糖激酶活性，并在糖尿病大鼠和健康大鼠之间进行比较。我们还使用实时PCR方法评估了磷酸果糖激酶-1酶在mRNA水平的表达。
本研究结果表明，桑叶提取物可显著提高糖尿病大鼠的肝葡萄糖激酶活性和血清胰岛素水平（p<0.05）。与对照组相比，它还显著降低了大鼠的血清葡萄糖水平（p<0.05）。此外，糖尿病大鼠的体重与初始体重相比显著下降（p<0.05）。然而，用桑叶治疗的糖尿病大鼠的体重与正常对照大鼠一样增加。
目前的研究结果表明，桑叶的降血糖作用是通过增加肝葡萄糖激酶活性和血清胰岛素水平来介导的。这些结果是支持桑叶作为糖尿病患者传统药物的额外的确凿证据。
