Production of the anticancer compound withaferin a from genetically transformed hairy root cultures of withania somnifera

Abstract

Withanolides (WTDs), well-known medicinally important compounds of Withania somnifera, including the anticancer compound withaferin A (WFA), are biosynthesized from their dedicated precursor squalene. Condensation of farnesyl pyrophosphate (FPP) molecules to produce squalene is catalyzed by squalene synthase (SQS). In the present study, the Arabidopsis thaliana squalene synthase gene (AtSQS1) was transformed in W. somnifera by Agrobacterium tumefaciens C58C1 (pRiA4). The AtSQS1 gene was detected in 87.88 % of induced transformed hairy roots (THRs). The results showed that the growth index (GI) of THRs after five weeks of culture was 2-fold higher than that of adventitious hairy roots (AHRs). The biomass doubling time of THRs and AHRs was 18 and 30 days, respectively. Quantitative evaluation of WFA in the studied roots showed that THRs contain 1.51-fold more WFA (330±0.87µg g-1 dry weight (DW)) than AHRs (218±0.17µg g-1 DW). These findings can be used for the production of WFA as a valuable anticancer compound through controlled and scaled up cultures of W. somnifera THRs.