The present work was aimed to appraise the biological activities and toxic potential of medicinal plant extracts of Ricinus communis, Datura innoxia and Croton tiglium. Different parts of selected plants were extracted separately through different extraction techniques using methanol which were further fractionated using polarity base solvents. The methanolic extracts as well as fractions were assayed for antioxidant, antimicrobial, cytotoxic (hemolytic, brine shrimp) and mutagenic (Ames) studies. The identified compounds from different plant parts were analyzed through advanced techniques such as GC-MS, LC-MS and NMR. The proximate composition of whole plant was also studied and variations in parameter were recorded among selected plants. The qualitative and quantitative phytochemicals screening, were also performed that these medicinal plants were rich source of different phytoconstituent. The biological assays showed that selected medicinal plants exhibited considerable antioxidant potential and selected plants extracts were also showing promising antimicrobial potential. It was also depicted from current study that the plant extracts also have potential of DNA protective conducted on the pBR322 DNA induced by UV and H2O2. The plant extracts found to be cytotoxic as evident from hemolytic, brine shrimp lethality and mutagenic activity by Ames test at variable levels. From in vivo study it was proved that Datura innoxia and Croton tiglium showed significant toxicity and developed micronucleus and also proved cellular damage against vital organs like liver and kidney. Amino acids of selected plant seeds were also profiled in which isoleucine and tryptophan remains undetectable among essential amino acids. Chemical compounds of selected plants oils were identified by GC-MS which showed significant antimicrobial activity against the selected microbial species. In LC-MS of methanolic extracts analysis wide ranges of phenolic compounds were documented. Moreover, compounds were also purified from methanolic extracts through column chromatography and characterized by advanced spectroscopic techniques like 1H-NMR, 13C-NMR, IR and ESI-MS, following compounds like apigenin, ursolic acid, rutin, chlorogenic acid and ferulic acid were first time reported from these plants. The current research study explored the selected medicinal plants in a very comprehensive fashion and presented their different biological aspects. In future these results may be used as foundation for large scale extraction and isolation of different bioactive compounds and their applications. Furthermore, detailed trials are recommended including animal model and cell lines.