ISSN: 0974 – 3987 IJBST (2009), 2(9):149-157 International Journal of BioSciences and Technology (2009), Volume 2, Issue 9, Page(s):149-157 149 Molecular characterization of Gymnema sylvestre using RAPD-PCR Gayathri Gunalan, A.J.Preethi, P.Sumathi and U.S. Mahadeva Rao Department of Biochemistry, S.R.M. Arts and Science College , Kattankulathur, Kanchipuram District-603203. Tamilnadu, India ggtarun@yahoo.com. ABSTRACT Herbal medicine is playing a major role in the control of many diseases, especially in developing countries like India. The conservation and utilization of these plants has attracted global attention. Diabetes mellitus is a endocrine syndrome which is characterized by insulin insufficiency or inefficiency. Besides many oral hypoglycemic drugs, there are certain anti-diabetic plants which can be used for the treatment of diabetes mellitus. Gymnema sylvestre is one of those anti-diabetic plants. To improve the cultivar of this Gymnema sylvestre, identification of their molecular markers should be done. RAPD-PCR can generate these molecular markers. The main objective of this study is to demonstrate the polymorphism that exists between five different ecotypes of Gymnema sylvestre. The RAPD-PCR was done with four primers. All the primers gave satisfactory amplification with maximum number of bands except one. Some bands were monomorphic and some were polymorphic. Thus the result reveals the presence of genetic diversity among five ecotypes of G.sylvestre. Keywords: Gymnema sylvestre, PCR, RAPD, DNA, anti diabetic plant. INTRODUCTION A Plant, which provides health-promoting characteristics, temporary relief or symptomatic problems or has curative properties, is generally called as medicinal plants. The medicinal plants are in great demand in tradition system of medicine i.e. ayurveda, siddha, unani and rig-veda, tibb as well as folklore prescriptions. About 80% of four billion people rely on traditional medicines due to high cost and lack of availability of required medicines. Out of 250,000 higher plants, more than 80,000 are having medicinal value and India occupies a unique position among world biodiversity center. It is estimated that 13,000 medicinal plant species are being used for the production of drugs. In India, almost 45,000 plant species are growing naturally or being cultivated. Herbal medicine is playing a major role in the control and cure of many diseases and about 75%-80% of the world's population is utilizing these medicines, especially in developing countries due to lesser side effects. Medicinal and Aromatic plants (MAPS) utilization and conservation has attracted global attention [1]. Several of these MAPS contained exceptionally high amounts of polysaccharides, polyphenols, tannins, hydrocolloids (sugars and carragenans) and other secondary metabolites such as alkaloids, flavanoids, phenols, terpenes and quinines which would interfere with the DNA isolation procedures [2]. Gymnema sylvestre, a family of Asclepidaceae, is a plant native to the tropical forests of India, and it has been used to treat a number of conditions. It is best known for its apparent ability to lower blood sugar levels. [3, 4,5,6,7,8,9]. Medicinally active parts of the plant are the leaves and roots. The active principle of this plant is an organic acid called gymnemic acid [10, 11]. This gymnemic acid suppresses the sweet taste not only of sucrose, but also the sweetness effect of sodium saccharin, cyclamate, glycine, D-alanine, D- tryptophan, D-leucine, beryllium chloride and lead acetate but not that of chloroform. [12,13,14,7,8,9]. Scientists from India find that the ethanolic extract of gymnema Sylvester leaves demonstrated antimicrobial activity against Bacillus pumilis, B. subtilis, Pseudomonas aeruginosa and Staphylococcus aureus and inactive against proteus vulgaris and Escherichia coli. [15]. Besides these properties gymnema also lower the serum cholesterol and triglyceride levels. [16]. The RAPD technique provides a convenient and rapid assessment of the difference in the genetic composition of the related individuals and has been employed in a large number of plants for the determination and assessment of genetic diversity. [17]. RAPD markers have been used for generating genetic linkage maps. [18,19,20] genotype fingerprinting [21], analyzing populations and pedigree [22], predicting phylogenies [23], studying population dynamics [24] and identifying clones [25]. RAPD reveals better polymorphism patterns and their primers used are universal. Laity fall (2003) [26] used RAPD to evaluate the genetic variations among cowpea varieties for the highest nitrogen fixing capacity[27] have stated that molecular markers are