Potential and Prospects of Shikonin Production Enhancement in Medicinal Plants

Abstract

Plants are a rich source of valuable chemicals that are used as herbal and modern medicines. Shikonin, a naphthoquinone red pigment, produced from roots of Arnebia hispidissima, A. euchroma, Lithospermum erythrorhizon and other Boraginaceous species was the first phytochemical to be produced on commercial scale using biotechnological approach. Plant cell culture technologies were the only tools employed for secondary metabolites production in other cases in past. Shikonin production and localization is tissue specific with stringent metabolic regulation. Hence, the differentiated cultures such as those of hairy root cultures offer a great promise for secondary metabolite production. A. rhizogenes-mediated transformed roots are characterized by high growth rate, genetic stability and growth in hormone free media. These genetically transformed root cultures can produce larger amounts of secondary metabolites. The present review deliberates upon potential and prospects of diverse physico-chemical factors that affect shikonin production in tissue culture, as well as, the genetic modification for enhancement of shikonin production.