A recent survey lists over 1400 genera of herbs that have a history of use in cancer treatments. Cancer continues to represent the largest cause of mortality in the world and claims over 6 million lives each year. On a yearly basis in US, 0.5% of the population is diagnosed with cancer. Agave americana belongs to family of Agavaceae. It is traditionally used in Africa to treat high blood pressure. Concentrated agave sap has antibacterial activity, and extracts from tropical agave plants have anti-inflammatory effects.Research is focusing on the search for new types of natural chemotherapeutic agent that is plant based medicines which are proving to be excellent sources of new compounds. In present research study, an attempt was made to prove cytotoxicity activity of various parts of medicinal plants such as Agave americana, Strychnos nux-vomica and Areca catechu using MCF-7 and Vero cell line. Various parts of the medicinal plants were extracted by soxhlet apparatus using solvents likes methanol and water.