Rosmarinic Acid Accumulation and Antioxidant Potential of Dracocephalum moldavica L. Cell Suspension Culture

Dracocephalum moldavica L. (Lamiaceae) is known for its medicinal properties; however greater yields can potentially be achieved by in vitro cultivation. A cell suspension culture of D. moldavica L. (Lamiaceae) derived from root-derived callus was established in liquid MS medium supplemented with 2,4-D 0.5 mg/l and BAP 0.2 mg/l. The biomass and rosmarinic acid (RA) content were analyzed during the 15-day growth cycle of the culture. The highest fresh and dry weight (14.29 g/flask and 1.14 g/flask, respectively) and RA level (27.2 mg/g DW) were reached at day 12 of culture. Methanolic extracts of the culture were assayed for total phenolic content using the Folin-Ciocalteau method, and antioxidant activities using three in vitro tests: ABTS radical scavenging, ferric ion reduction (FRAP) and lipid peroxidation (LPO). RA content and antioxidant potential were found to be higher in cell suspension culture than in root-derived callus. The cell suspension culture also exhibited higher concentrations of RA and ABTS radical scavenging activity than those of the aerial parts of six-month-old field-grown plants of D. moldavica. The overall results show a significant correlation between antioxidant activity, total phenolic content and RA content of the examined extracts. The study presents for the first time the use of cell cultures of D. moldavica for production of therapeutically-valuable metabolites. Our results suggest that the obtained culture could be considered as a potential source of rosmarinic acid, a compound known for its strong antioxidant activity.