Biomass production and withaferin a synthesis by Withania somnifera grown in aeroponics and hydroponics

The medicinal herb Withania somnifera (L.) Dunal (Solanaceae) was grown in two soilless systems to determine optimal conditions for production of biomass and withaferin A, the major secondary metabolite responsible for its claimed medicinal properties. Withaferin A content was analyzed using high-performance liquid chromatography (HPLC). The results show that there was no statistically significant difference (P > 0.05; t test) in biomass production between the plants grown aeroponically and hydroponically. Aeroponically grown plants produced an average of 49.8 g dried aerial plant material (DW) (SD 20.7) per plant, whereas hydroponically grown plants produced an average of 57.6 g DW (SD 16.0). In contrast, withaferin A content was statistically higher in plants grown hydroponically. These plants contained an average of 7.8 mg·g^-1 DW (SD 0.3), whereas the aeroponically grown plants contained an average of 5.9 mg·g^-1 DW (SD 0.6). These results demonstrate that hydroponic techniques are optimal in reproducibly and efficiently generating withaferin A. These findings may be of importance to the natural products industry in seeking to maximize production of biologically active compounds from medicinal plants.