The study was designed to determine the phytochemical constituents and to evaluate several biological activities of crude methanol extracts of a native plant, Murdannia nudiflora, an exotic plant, Tradescantia pallida, and a common spice, Piper nigrum, as well as their organic soluble fractions. Preliminary phytochemical screening confirmed the presence of several secondary metabolites.The petroleum ether extract of P. nigrum exhibited the highest degree of cytotoxicity (LC50=3.524 μg/ml) whereas that of M. nudiflora and T. pallida were quite low. Antioxidant studies of the plant extracts yielded prominent results where the free radical scavenging potential of M. Nudiflora and T. Pallida were found to be 95.76 ± 1.34 mg/100g and 97.15 ± 0.96mg/100g of AAE, respectively, whereas, IC50 values of M. nudiflora and T. pallida were 1.51x10-10μg/ml and 4.209x10-13μg/ml, respectively, justifying the presence of high concentration of flavonoids. In addition, the analgesic studies of M. nudiflora and T. Pallida revealed significant inhibition of writhing upon induction of pain by acetic acid (p<0.001, p<0.05, respectively). The chloroform extract of P.nigrum showed 61.27% inhibition of hypotonic solution induced and 96.61% inhibition of heat induced haemolysis, while the methanolic extract of the plant produced 30.74% of clot lysis confirming a moderate thrombolytic activity. Thus, the present study strives to provide a scientific basis of the traditional uses of the medicinal plants.