The prime action of Holy Basil (also known as Tulsi) in cancer control comes from its ability to inhibit an enzyme called COX-2 that stimulates an inflammatory response in the body and triggers cancerous activities. Holy basil, by blocking the action of this enzyme, prevents inflammation and reduces pain. The active component of the leaves of Holy Basil, eugenol, inhibits the division and migration of the cancer cells. It also prevents the cancer cells from invading into the surrounding structures and induces apoptosis (the process of programmed cell death).
Additionally, Holy Basil contains several other cancer-fighting phytochemicals including apigenin, rosmarinic acid, luteolin, myretenal, carnosic acid and beta-sitosterol. These compounds stimulate the antioxidant activity and destroy the cancer cells. Holy basil is effective in inhibiting the growth and progression of breast cancer by blocking the cell proliferation. It also prevents angiogenesis, a process by which new blood vessels are formed within the cancer mass. As a result of this, the cancer cells do not get oxygen and nutrition needed for their survival resulting in their death.