The juice of fresh leaves of Catharanthus roseus Linn. reduces blood glucose in normal and alloxan diabetic rabbits.
BACKGROUND
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Nammi
Srinivas
S
Pharmacology Division, Department of Pharmaceutical Sciences, Andhra University, Visakhapatnam-530 003, Andhra Pradesh, India. nammi@rediffmail.com
Boini
Murthy K
MK
Lodagala
Srinivas D
SD
Behara
Ravindra Babu S
RB
D000496:Alloxan; D000818:Animals; D001786:Blood Glucose / Q000187:drug effects; D030008:Catharanthus; D003921:Diabetes Mellitus, Experimental / Q000139:chemically induced / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D005905:Glyburide / Q000494:pharmacology; D007004:Hypoglycemic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use; D018515:Plant Leaves; D011817:Rabbits
D001786:Blood Glucose; C046419:Catharanthus roseus extract; D007004:Hypoglycemic Agents; D010936:Plant Extracts; D000496:Alloxan; D005905:Glyburide