Research in Medicinal plants

A wide variety of diseases are associated with increase in oxidative stress. Increased oxidative stress is also associated in progression of a wide variety of complications especially degenerative diseases. Intake of natural antioxidants has been suggested to reduce the risk of these diseases. Free radicals are considered as molecules with unpaired electron which are involved in a lot of biochemical activities of cells including gene transcription, regulation of soluble guanylate cyclase activity and signal transduction. Humans and animals are generally exposed to free radicals from cellular metabolisms as well as the manmade free radicals in environment such as cigarette smoke and pollutants or natural resources such as ultraviolet, radon, and cosmic radiation. Reactive oxygen species (ROS) and Reactive Nitrogen Species (RNS) are the most important free radicals which induce oxidative stress. They are suspected to be involved in inflammation, tissue damage, proteins and DNA injury, and subsequent cellular apoptosis. They may cause neurodegenerative diseases including cardiovascular complications, diabetes, Parkinson’s disease, Alzheimer’s disease and Multiple sclerosis. Antioxidants are being looked upon as persuasive therapeutic agents against free radical induced diseases. They have capability to combat them by neutralizing free radicals. The most important cellular free radicals are superoxide (O2–·), hydroxyl (OH·) and nitric monoxide (NO·). Nitric oxide (NO) is a signaling molecule which regulates leukocytes adhesion, platelets aggregation, relaxation and proliferation of vascular smooth muscle cells, hemodynamics angiogenesis, thrombosis, and vascular tone. Therefore, in cases that free radicals are substantially involved in a disease, antioxidants should be beneficial to be used alone or in combination with other drugs. Moreover, most of drugs cause toxicities in high or regular doses and increase free radicals inducing oxidative stress. Hence, the use of antioxidant plants with these drugs should be useful in reducing the toxic effects of these drugs. This matter is also a good field for researchers to investigate the possible beneficial effects of antioxidant plants on toxicity induced by drugs.