Elicitation Effects of Fungal Extracts on Silymarin Accumulation in Silybum marianum (L.) Gaertn Hairy Root Culture

Background: Silymarin, extracted from the seeds of milk thistle (Silybum marianum (L.) Gaertn) is mostly used for liver disease treatment. Hairy root cultures derived from S. marianum are able to produce silymarin. Objective: Elicitation of hairy root cultures is an important strategy for improving the production of secondary metabolites. The elicitors could be changed metabolite biosynthesis pathway and are useful for study of cell signaling pathway. Methods: In this study after preparation of S. marianum hairy root cultures, the effects of various levels of Fusarium oxysprum and Phytophtora meloni extract (0, 10 and 20 mg 50 ml-1 culture) in 4 different exposure times (0, 24, 48 and 72 h) have been investigated on flavonolignans production. The flavonolignans were analyzed by High Performance Liquid Chromatography method. Results: Our results showed that hairy root cultures of S. marianum were consisted of a large number of flavonolignans including silychristin, silydianin, silybin, isosilybin and taxifolin. The highest production of silymarin (0.32 mg g-1 DW) was observed in F. oxysprum elicited root cultures (10 mg/50 ml culture) after 72h (2.28- fold that of the control). In Ph. meloni treated root cultures (20 mg/50 ml culture), the maximum silymarin production (0.13 mg g-1 DW) was obtained after 72 h (1.9- fold that of the control). Conclusion: In this experiment it has been concluded that hairy root cultures of S. marianum are susceptible to elicitation by fungal elicitors and is useful for efficient large-scale production of silymarin by hairy root cultures of S. marianum.