Antioxidant, Antiglycation Potentials and Total Phenolic Content of Scoparia dulcis Decoction

Long term diabetes mellitus increases the risk of many micro and macro vascular diabetic complications and oxidative stress, due to formation of excessive amounts of free radicals. Non enzymatic protein glycation is the key molecular basis of the above complications observed in diabetic individuals. The current tendency to use herbal treatments in diabetes mellitus is mainly due to the therapeutic efficacy, safety, low cost and minimal adverse effects. Among the many herbs used, the decoction prepared using the whole plant of Scoparia dulcis is a frequently used traditional medicine in the treatment of diabetes mellitus.Since no data are available on the antiglycation potential of the decoction of S. dulcis plant this study focused on determining the antiglycation potential, DPPH and ABTS antioxidant potentials and total phenolic content of the S. dulcis decoction.The commercially available dried S. dulcis and three other fresh samples collected from three different areas were used for the study. The DPPH and ABTS antioxidant potentials of the samples were in the range of 450-540 μg mL-1 and 549-615 TEAC mmol g-1 respectively. Antiglycation potentials of the four samples were in the range of 131-230 μg mL-1 and total phenolic contents were 160-186 mg/GAE/g. The results of the study prove the effectiveness of the use of S. dulcis plant in traditional medicine for diabetes.Keywords: S. dulcis, decoction, antiglycation, antioxidant, phenolic contents, traditional medicin

Free radical Scavenging Activity and Phenolic content of decoctions of some medicinal plants

Free radicals are normally generated in substantial amounts in the body; excessive amounts cause oxidative damage through chain reactions forming disorders like diabetes mellitus, cardiovascular and pulmonary diseases. In diabetic conditions, a non enzymatic reaction occurs with proteins and reducing sugars forming glycated protein named Amadori products. Further rearrangement, oxidation and reduction of Amadori products leads to form Advanced Glycated End products which causing spontaneous damage to proteins in physiological system leading various complications like Nephropathy, Neuropathy ,Retinopathy and this process accompanying the formation of free radicals. In this process oxidation plays an important role to form Advanced Glycated End Products. Therefore antioxidants are highly important in prevention or slowing the glycation reaction. Humans have evolved a complex antioxidant system, but this may not be sufficient to maintain optimal cellular functions in diabetic conditions. Medicinal plants usually contain different phenolic compounds having antioxidant properties. Therefore, a study was carried out to examine the in vitro free radical scavenging activity and total phenolic content of the decoctions of plants, Cassia auriculata (Ranawara, flower) Phyllanthus emblica (Nelli, fruit) and Scoparia dulcis (Walkottamalli, whole plant) which are used in the treatment for diabetics. Three fresh samples from each plant collected from different areas where they are grown and commercial dried sample from the traditional market was selected to prepare the decoctions and compared phenolic contents and antioxidant activity. The total phenolic content of each extract was determined using Folin-Ciocalteu reagent and evaluation of free radical scavenging activity was assessed using DPPH assay and ABTS assay. Decoctions of the commercial samples of P. emblica showed the highest total phenolic content as 625 mgGAE/g and C auriculata and S dulcis showed 459 and 131 mgGAE/g respectively. Samples dried under laboratory conditions of C.auriculata had total phenolic content from 226 – 287 mgGAE/g, P.emblica from 479 -517 mgGAE/g and S dulcis from 167 – 186 mgGAE/g. The highest DPPH antioxidant activity showed the commercial sample of P. emblica as 27 μg/ml and other samples dried under laboratory conditions were in the range of 41 – 49 μg/ml. No significant difference between the DPPH activity of C. auriculata commercial sample and other samples dried in the dehydrator and were in the range of 248 -309 μg/ml while S. dulcis all the samples showed DPPH antioxidant activity from 437 – 540 μg/ml. The reference standard, Butylated Hydroxy Toluene showed 20 μg/ml. ABTS antioxidant activity was high in all commercial samples of C.auriculata, P.emblica and S. dulcis and were as 648,625 and 615 mmol/g while other samples dried using the dehydrator showed 313 – 536 mmol/g,479 -517 mmol/g and 549-550 mmol/g respectively.Key words: Antioxidant properties, Glycation, Diabetes, DPPH assay, ABTS assa