Nammi Srinivas, Boini Murthy K, Lodagala Srinivas D, Behara Ravindra Babu S
Pharmacology Division, Department of Pharmaceutical Sciences, Andhra University, Visakhapatnam-530 003, Andhra Pradesh, India.
BMC Complement Altern Med. 2003 Sep 2;3:4. doi: 10.1186/1472-6882-3-4.
The leaf juice or water decoction of Catharanthus roseus L. (Apocyanaceae) is used as a folk medicine for the treatment of diabetes all over the world. In the present investigation, the leaf juice of C. roseus has been evaluated for its hypoglycemic activity in normal and alloxan-induced diabetic rabbits.
The blood glucose lowering activity of the leaf juice was studied in normal and alloxan-induced (100 mg/kg, i.v.) diabetic rabbits, after oral administration at doses of 0.5, 0.75 and 1.0 ml/kg body weight. Blood samples were collected from the marginal ear vein before and also at 4, 6, 8, 10, 12, 16, 18, 20 & 24 h after drug administration and blood glucose was analyzed by Nelson-Somogyi's method using a visible spectrophotometer. The data was compared statistically by using Student's t-test.
The leaf juice of C. roseus produced dose-dependent reduction in blood glucose of both normal and diabetic rabbits and comparable with that of the standard drug, glibenclamide. The results indicate a prolonged action in reduction of blood glucose by C. roseus and the mode of action of the active compound(s) of C. roseus is probably mediated through enhance secretion of insulin from the beta-cells of Langerhans or through extrapancreatic mechanism.
The present study clearly indicated a significant antidiabetic activity with the leaf juice of Catharanthus roseus and supports the traditional usage of the fresh leaves by Ayurvedic physicians for the control of diabetes.
长春花（夹竹桃科）的叶汁或水煎剂在世界各地被用作治疗糖尿病的民间药物。在本研究中，已对长春花叶汁在正常和四氧嘧啶诱导的糖尿病兔中的降血糖活性进行了评估。
在正常和四氧嘧啶诱导（100mg/kg，静脉注射）的糖尿病兔中，以0.5、0.75和1.0ml/kg体重的剂量口服给药后，研究叶汁的降血糖活性。在给药前以及给药后4、6、8、10、12、16、18、20和24小时从耳缘静脉采集血样，并使用可见分光光度计通过纳尔逊-索莫吉法分析血糖。使用学生t检验对数据进行统计学比较。
长春花叶汁使正常和糖尿病兔的血糖均呈剂量依赖性降低，且与标准药物格列本脲相当。结果表明长春花降低血糖的作用具有长效性，长春花活性化合物的作用模式可能是通过增强胰岛β细胞分泌胰岛素或通过胰腺外机制介导的。
本研究清楚地表明长春花叶汁具有显著的抗糖尿病活性，并支持阿育吠陀医生使用新鲜叶子控制糖尿病的传统用法。
