Evaluation of Antioxidant Activity of Spilanthes calva, Solanum virginianum, Stevia rebaudiana, Ruellia tuberosa and Phytochemical Investigation of Mikania cordata

This thesis submitted in partial fulfillment of the requirements for the degree of Bachelor of Pharmacy (B.Pharm) in East West University, Dhaka, Bangladesh.Antioxidant assay is widely used by the pharmaceutical industries to screen for antioxidant activity in compound libraries. In present study five plant samples were selected to conduct the antioxidant activity; these are Spilanthes calva, Solanum virginianum, Stevia rebaudiana, Ruellia tuberosa and Mikania cordata. In total phenolic content assay Stevia rebaudiana has the highest amount of phenolic content than other extracts. Spilanthes calva has the least amount of phenolic content among all extracts. DPPH radical activity of methanolic extract of Stevia rebaudiana is good after which is methanolic fraction of Mikania cordata. In Nitric oxide scavenging assay Solanum virginianum is good after which is methanolic extract of Stevia rebaudiana. In reducing power assay Solanum virginianum showed highest level of reducing power where as Stevia rebaudiana and Ruellia tuberosa showed moderate reducing power activity. Among all different fractions of Mikania cordata methanolic fraction showed the highest antioxidant activity. In Column chromatography, I used an open column to purify individual chemical compounds from mixtures of compounds. The methanolic extract of Mikania cordata was subjected to open column and different fractions were collected using four different solvents. Lastly I experimented these fractions to identify their antioxidant property