Andrographis paniculata, commonly known as ‘king of Bitters’is an herbaceous plant from Acanthaceae family predominant in south Asia. The leaves of this plant have been traditionally used as a folklore remedy for a wide spectrum of ailments and in India it is used in Ayurveda medicine. The beneficial components of this plant can function as reducing and capping agent to synthesis nanoparticles with biomedical applications. Hence for the first time we have used the leaf extract of this plant and optimized the synthesis of silver nanoparticles. Characterization studies reveal that the particles exhibited Surface Plasmon peak at 430 nm. TEM image showed spherical morphology and size range of 20–50 nm. XRD and Raman spectral peaks also confirmed the presence of silver nanoparticles. FTIR and Raman spectra revealed the functional groups present on the silver nanoparticles. The antioxidant activity of the particles was evaluated in erythrocyte model and the particles prevented oxidative stress in vitro. We speculate that the particles have biomedical attributes as most of diseases are associated with antioxidant imbalance and oxidative stress.