IMPROVEMENT OF SILYMARIN CONTENT IN CELL CULTURES OF Silybum marianum BY COPPER SULPHATE ELICITOR

Abstract

Silybum marianum L. (Milk thistle) extracts are the main source of silymarin that is a mixture of various flavonolignan (silybin (silibinin), silydianin and silychristin). Silymarin of milk thistle has a hepatoprotective activity for liver cirrhosis and chronic inflammatory. Silybum marianum regeneration from hypocotyl explants and evaluation of their callogenesis, growth and total flavolignan (silymarin) upon copper sulphate (as abiotic elicitor) elicitation was targeted. Copper sulphate (CuSO 4) was applied in concentrations of 0, 3, 5, 7 and 9 µM to elicit the silymarin production in cultures. The elicitation periods used in this study were 2, 4, 7, 14 and 28 days. Half-strength MS medium recorded better results relative to full-strength MS one and seed incubation in the darkness at room temperature resulted in rapid germination and reached to the gar lid after 10 days. Callus fresh and dry weights as well as growth index were gradually increased with increasing the copper sulphate concentration till 5 µM while decreased thereafter at any elicitation period. With the increase of the elicitation period, the increase of the previous parameters was observed. Flavonolignan (silymarin) was positively correlated with CuSO 4 levels since all levels of copper sulphate significantly enhanced its content in relative to the control. Additionally, more silymarin was accumulated after 4 or 7 days and the accumulation significantly decreased when the elicitation period reached 14 days more. The highest silymarin (flavolignan) content (11.79 and 11.67 mg g-1 DW) was obtained when 5 or 7 µM copper sulphate levels were combined with 4 days elicitation period, being about five-fold of the control.

Effect of gamma rays and colchicine on silymarin production in cell suspension cultures of Silybum marianum: A transcriptomic study of key genes involved in the biosynthetic pathway

“…Seeds of S. marianum were cultured on half-strength MS medium supplemented with 3% (w/v) sucrose and solidified with 3 g/L phytagel. The use of half-strength MS medium for seed germination gave comparable results with those of Elsharnouby and Hassan (2018), who reported that it was better than the full-strength medium, due to the osmotic pressure of the latter. Also, the germination process was enhanced by incubating the seeds in complete darkness until seedling formation.…”

“…Also, the germination process was enhanced by incubating the seeds in complete darkness until seedling formation. These results are corroborated by Elsharnouby and Hassan (2018), who stated that light was unnecessary in the germination period of S. marianum seeds due to its inhibitory effect ( Khan et al, 2013).…”

“…Meanwhile, Eari et al (2017) found that 1 mg/L or 1.5 mg/L 2,4-D and Kin were the most effective concentrations for callus induction from root explants of S. marianum. Furthermore, the culture of different explants of S. marianum seedlings on MS medium supplemented with 1 mg/L 2,4-D, in combination with 0.5 mg/L BA, produced large undifferentiated friable calli (Elsharnouby and Hassan, 2018). Supplementing MS medium with 2,4-D + Kin caused a significant increase in the callus induction rate.…”

Optimization of silybin production fromSilybum marianumtissue cell cultures using different elicitor solutions

“…Adding CuSO 4 to the culture media of S. marianum calluses has increased silymarin content by four to five folds relative to the control (Elsharnouby & Hassan, 2018).…”

“…In fact, the presence of heavy metal ions trigger changes in metabolic activities of plants and affect the production of photosynthetic pigments, sugars, proteins, and non‐protein thiols Thakur et al, 2019). Adding CuSO 4 to the culture media of S. marianum calluses has increased silymarin content by four to five folds relative to the control (Elsharnouby & Hassan, 2018).…”