According to the International Union for Conservation of Nature and the World Wildlife Fund, about 50,000–80,000 of flowering plants are used because of their medicinal values [1, 2].
Medicinal plants are the major sources of numerous valuable chemicals and/or drugs. Over 1300 medicinal plants are used in European countries, and out of them, 90% are from wild sources. According to the International Union for Conservation of Nature and the World Wildlife Fund, about 50,000–80,000 of flowering plants are used because of their medicinal values [1, 2]. Also, the National Medicinal Plant Board India has estimated that India has 17,000–18,000 species of flowering plants, out of which 6000–7000 are known to have medicinal application in ancient medicinal systems such as ayurveda, siddha, unani, and homeopathy. About 960 medicinal plants are in trade industry of which only 178 are known to have annual consumption levels of more than 100 MT (metric tons) [3]. The increase in human population and the demand for natural medicines have aggravated the loss of medicinal plant species, 100–1000 times the rate of natural extinction. Although this threat has been known for decades, it has resulted to the increase in loss of species and habitat destruction worldwide [1]. This chapter reviews the advances in the application of tissue culture for the in vitro regeneration of rare endangered or threatened medicinal plants and enhancement of various pharmaceutics, drugs, flavors, colors, and medicinal compound production in medicinal plants.