Biosynthesis and pharmacological evaluation of shikonin – A highly valuable metabolite of Nor th-Western Himalayas: Mini Review

Abstract

Shikonin is one of most important secondary metabolite having vast medicinal properties. The source for shikonin and its derviatives are mainly the roots and rhizomes of Boraginaceae family which include Lithospermum erythrorhizon, Arnebia euchroma, Arnebia benthamii, A. guttata, A. hispidissima, A. nobilis, A. decumbens, A. nandadeiensi, Arnebia griffithi and Onosma paniculatum. Shikonin and its derivatives have high value in the international market attributed to its pharmacological applications. Most of the plant species used for extraction of shikonin have been listed endangered because of their over exploitation and hence there is a need to identify alternative sources to meet the escalating demand of this valuable metabolite. The biosynthetic pathway of shikonin has remained elusive or fragmentary. Poor understanding of biosynthetic pathway limits the large scale shikonin production. A genetic intervention coupled with biosynthetic pathway understanding will be helpful for enhanced production that eventually fulf ill the industrial requirements. We therefore, give a brief review on our current understanding and limitations of shikonin biosynthesis along with their pharmacological properties