|ISSN No. 1606-7754 Vol.15 No.3 December 2007|
Effect of aqueous and ethanol extracts of Cassia auriculata L. flowers on diabetes using alloxan induced diabetic rats
F Lukmanul Hakkim 1, S Girija 1, R Senthil Kumar 2, MD Jalaludeen 2
Department of Biotechnology, Bharathiar University, Coimbatore- 641 046, Tamilnadu, India,1 Department of Biochemistry, Mohammed Institute of Education and Technology, Tiruchirappalli, Tamilnadu, India. 2
In the present study the antidiabetic potential of aqueous and ethanol extract of Cassia auriculata L. flowers was assessed in alloxan-induced diabetic rats. The phytochemical screening and antioxidant activity were made in these extracts. Antidiabetic agents (Flavonoids and phenolic acids) and free radical scavenging activity in water-soluble fraction of the ethanol extract was higher compared to that of aqueous extract. Diabetic rats showed increase in blood glucose (p<0.01) and decrease in plasma insulin (p<0.01) levels after 48 hrs of alloxan administration. The oral administration of water-soluble fraction of the ethanol extract at a dose of 0.25 and 0.5g/kg of body of weight, for 30 days exhibited a significant (p<0.001) reduction in the blood glucose level and a remarkable increase in plasma insulin level compared to the aqueous extract-treated rats and diabetic control. The level of serum triglycerides and total cholesterol were significantly (p<0.01) increased in diabetic rats. The marker enzymes of liver toxicity such as serum alanine transaminase (ALT), serum aspartate transaminase (AST), serum acid phosphatase (ACP), and serum alkaline phosphatase (ALP) were elevated significantly (p<0.01) in diabetic control. The liver glycogen and glycogen synthase levels were also increased significantly (p<0.01) in alloxan-induced diabetic rats. In addition changes in the body weight and food intake were also analyzed in diabetic and the extracts-treated rats. Treatment with water soluble fraction of ethanol extract and aqueous extract of C. auriculata flowers restored the above altered parameters significantly in diabetic animals. The water soluble fraction of the ethanol extract showed a more efficient antihyperglycemic effect compared to the aqueous extract.
Keywords: Cassia auriculata, Alloxan, Antidiabetic effect, Water soluble fraction, Aqueous extract
Diabetes mellitus is a metabolic disorder featured by hyperglycemia and alterations in carbohydrate, fat and protein metabolism associated with absolute or relative deficiency of insulin secretion and /or insulin action.1 It is one of the oldest diseases affecting millions of people all over the world.2 Although numerous oral hypoglycemic drugs exist alongside insulin, still there is no promising therapy to cure diabetes.3 Over the last few decades the reputation of herbal remedies has increased globally due to its therapeutic efficacy and safety. Herbal drugs are widely prescribed today despite the fact that their biologically active compounds are unknown, due to its minimal adverse effects and low costs.4 In recent years, numerous traditional medicinal plants were tested for their antidiabetic potential in the experimental animals.5 In the present investigation, Cassia auriculata L. flowers were tested for their antidiabetic efficacy. C. auriculata (family: Cesalpinaceae) is a common plant in Asia, profoundly used in Ayurvedic medicine as a tonic, astringent and as a remedy for diabetes, conjunctivitis and opthalmia.6 It is one of the principle constituents of ‘Avaarai panchaga chooranam’- an Indian herbal formulation used in the treatment of diabetes to control the blood sugar level.7 The antidiabetic activity of aqueous extract of C. auriculata flowers has been documented previously.8 Our in vitro studies revealed that the water-soluble fraction of ethanol extract has more antioxidant potential than aqueous extract of C. auriculata flowers i.e. the potential of scavenging the free radicals by water-soluble fraction of ethanol extract has more efficient than the aqueous extract. It is known that free radicals formation is elevated in diabetes and its complications.9 In view of the above consideration, the present study was designed to investigate the comparative antidiabetic efficacy of aqueous and ethanol extracts of C. auriculata flowers in alloxan-induced diabetic rats.