Optimization of shikonin production in Onosma dichroantha callus using response surface methodology

Abstract

The roots of Onosma dichroantha, contain substantial amounts of shikonin/alkannin derivatives, which are considered as edible natural colors with distinguished anti-inflammatory, antibacterial, antiviral, as well as antitumor activities. In this study, a response surface methodology coupled with numerical optimization modeling techniques were implemented to analyze and optimize the individual as well as interactive effects of two important plant growth regulators (indole acetic acid, IAA and benzylaminopurine, BAP) on the relative growth rate (RGR) and shikonin production of O. dichroantha callus grown on three growth media. Callus growth was best on B5 medium, and shikonin production was best on M9 medium, while White medium was best for synchronized callus growth and shikonin production. Upon statistical optimization, the maximum RGR and shikonin production of callus grown on B5 medium were predicted in 0.93 mg L⁻¹ BAP and 0.16 mg L⁻¹ IAA, on M9 medium in 0.55 mg L⁻¹ BAP and 0.16 mg L⁻¹ IAA, and on White medium in 1.23 mg L⁻¹ BAP and 0.11 mg L⁻¹ IAA. These data can be employed in development of large scale production of shikonin derivatives using O. dichroantha.