The medicinal properties of plants are due to the presence of active principles. These bioactive secondary metabolites are synthesized by two principal pathways: shikimic acid or aromatic amino acid, and mevalonic acid. Alkaloids, phenolics and terpenoids constitute many pharmacologically active compounds. Antioxidants are vital substances which possess the ability to protect the body from damage caused by free radical induced oxidative stress. Epidemiological studies specify that intake of fruits and vegetables have the ability to inhibit the damaging behaviour of free radicals in the human body. Free radicals which induce oxidative damage of cellular lipids, nucleic acids and proteins are thought to be one of the major risks for diseases such as cancer, atherosclerosis, diabetes mellitus and various other degenerative diseases. Numerous natural free radical scavengers and antioxidants can protect biomolecules against the attack of free radicals or may suppress injury caused by them. Two leaf extract of Elettaria cardamomumand Ferula assa-foetida leaves, were prepared in methanol and subjected to test the extent of inhibition of in vitro lipid peroxidation by using lipid membrane preparations of RBC ghosts. Both the extracts caused a substantial decline in the extent of LPO in RBS ghosts. The decrease in LPO was more pronounced in Ferula assa-foetida leaves extract.
