Andrographis paniculata, commonly known as Kalmegh, is one of the most popular medicinally important plants in India. The main constituents of this plant are two lactone diterpenoids namely andrographolide and deoxy-andrographolde. It is used traditionally for the treatment of several diseases such as diabetes, high blood pressure, ulcer, skin dieses, cancer and malaria since ancient times. In this review, the medicinal properties of Andrographis paniculata and its chemical constituents have been discussed.

Nanotechnology is the most promising area of research for its wide range of applications. It deals with the creation and control of particles having size 1-100 nm at least one of their dimensions. Metal nano particles are important component of nanoscience. Various methods have been developed and modified for the synthesis of metal nanoparticles. Among the several methods biogenic reduction of metal salts to corresponding metal nano particle is a green method due to low cost, absence of hazardous chemicals, without drastic condition, very mild and eco-friendly reaction condition. In this review, bio based synthesis and applications of silver, gold and palladium nanoparticles have been discussed.