Inhibition of angiogenesis is currently perceived as one of the promising strategies in the treatment of cancer. In this study we analyzed the antiangiogenic activity of Andrographis paniculata extract (APE) and its major component andrographolide (ANDLE) using both in vitro and in vivo models. Intraperitoneal administration of APE and ANDLE significantly inhibited the B16F-10 melanoma cell line induced capillary formation in C57BL/6 mice. Analysis of serum cytokine profile showed a drastic elevation in the proinflammatory cytokines such as IL-1beta, IL-6, TNF-alpha and GM-CSF and the most potent angiogenic factor VEGF in angiogenesis induced animals. Treatment of APE and ANDLE significantly reduced this elevated levels. Moreover, VEGF mRNA level in B16F-10 cell line showed a reduced level of expression in the presence of APE and ANDLE. Serum NO level which was increased in B16F-10 melanoma injected control animals was also found to be significantly lowered by the administration of APE and ANDLE. Antiangiogenic factors such as TIMP-1 and IL-2 level was elevated in APE and ANDLE treated angiogenesis induced animals. In the rat aortic ring assay APE and ANDLE inhibited the microvessel outgrowth at non toxic concentrations. Taken together our results demonstrate that APE and ANDLE inhibit the tumor specific angiogenesis by regulating the production of various pro and antiangiogenic factors such as proinflammatory cytokine, nitric oxide, VEGF, IL-2 and TIMP-1.