The present scientific investigation deals with the extraction of some Indian medicinal plants include, Manilkara hexandra Roxb. stem bark (Sapotaceae), Strychnous potatorum Linn. dried seeds (Loganiaceae), Salacia reticulata Wight. stem bark (Celastraceae) and identification of chemical constituents by using preliminary phytochemical tests. The extracts were screened for their potential in-vitro anti-diabetic studies so as to ensure the biological potency of the plant. The study also includes qualitative screening of the phytonutrients, Free radical scavenging activity by DPPH assay method and assessment of total antioxidant activity by phosphor-molybdate assay method were evaluated. From the study we revealed that the all plants contain various classes of secondary metabolites and also possess a moderate anti-diabetic activity it terms of alpha amylase inhibition.