The effect of temperature and pH on biomass and bioactive compound production in Silybum marianum hairy root cultures

Background and objectives: The seed extract of Silybum marianum contains seven flavonolignans known collectively as silymarin. These metabolites can be produced in hairy root cultures of S. marianum. The effect of different physical factors can change root biomass and silymarin production which has been investigated in the present study. Methods: The effect of different physical factors of temperature (30 ºC/25 ºC, 25 ºC/25 ºC and 15 ºC/20 ºC in 16 h/8 h cycle) and pH (5, 5.7, 6 and 7) were evaluated with respect to the root biomass and silymarin production in hairy root cultures of the plant. Results: Incubation temperature, 25 ºC /25 ºC promoted the silymarin production in 4-week old hairy roots (0.18 mg/g DW) as compared with the cultures treated with 15 ºC/20 ºC and 30 ºC/25 ºC (0.13 and 0.12 mg/g DW, respectively). Maximal increases in biomass and silymarin accumulation occurred in the root cultures grown in pH 5 and 25 ºC/25 ºC (0.45 g and 0.26 mg/g DW). The content of silybin, isosilybin, silychristin, silydianin were 0.025, 0.024, 0.061 and 0.095 mg/g DW, respectively which were higher than those grown in higher pH. Conclusion: The results of the present study suggest that 25 ºC/25 ºC and acidic environment of medium are beneficial for silymarin production using hairy root cultures. Furthermore, lipoxygenase (LOX) activity was strongly affected by pH which suggested that acidic environment may act as inducing signal for LOX activity and subsequently greater silymarin production

Assessment of chemical composition of essential oil of Ferula assa-foetida oleo-gum-resin from two different sites of Yazd province in center of Iran

In this experiment, the chemical composition of the essential oils obtained from Ferula assa-foetida oleo-gum resin collected from two different sites of Yazd province (Tabas and Yazd) in the center of Iran, were identified. The gas chromatography mass-spectroscopy (GC/MS) data showed that the qualitative composition of the components appeared to be constant in two different regions. Moreover, no remarkable variations were found in the amounts of the essential oil major constituents. A total thirty-nine components, comprising 91.52% and 95.61% of the total oil, were characterized in Tabas and Yazd samples, respectively. The hydrodistilled oils contained E-1-propenyl sec-butyl disulfide (40.15 and 44.36% in Tabas and Yazd samples, respectively), Z-1-propenyl sec-butyl disulfide (23.93 and 27.98%), Guaiol (5.50 and 3.14%) and Carotol (5.14 and 1.63%) as major constituents

Trichoderma strains- Silybum marianum hairy root cultures interactions

Background and objectives: Silymarin is a unique flavonoid complex with documented hepatoprotective properties. Silybum  marianum hairy root culture as a source for producing silymarin has been an important strategy for study the cell signaling pathway. In the present investigation Trichoderma strains- Silybum marianum hairy root cultures interactions have been studied. Methods: The effects of two Trichoderma Strains (KHB and G46-7) (0, 0.5, 1, 2 and 4 mg/ 50 mL culture) in 6 different exposure times (0, 24, 48, 72, 96 and 120 h) have been investigated on flavonolignans production. The flavonolignans were analyzed by High Performance Liquid Chromatography method. Cell signaling pathway was evaluated by determination of H2O2 content, peroxidase and ascorbate peroxidase activities. Results:The elicitation effects of two Trichoderma Strains (KHB and G46-7) were examined on flavonolignans accumulation and the activation of cell defense system in S. marianum hairy root cultures. The results indicated that the highest silymarin accumulation (0.45 and 0.33 mg/g DW) was obtained in media elicited with 0.5 mg/50 mL cultures of T. harzianum Strains (KHB and G46-3, respectively) after 120 h. Feeding time experiments indicated that a significant higher content of silymarin production was achieved after 120 and 72 h in media treated with 0.5 mg/50 mL cultures of KHB and G46-3, respectively. Our results showed that S. marianum treated by KHB strain, increased taxifolin, silychristin, isosilybin and silydianin productions significantly. The H2O2 content in the control hairy root cultures remained lower than the treated cultures. There was significant enhancement in both peroxidase and ascorbate peroxidase activities in treated hairy roots reaching a peak after 72 h. Conclusion: These findings suggested that some Trichoderma strains are positive elicitors for promoting silymarin accumulation in S. marianum hairy root cultures. The results also suggested the presence of H2O2 and oxidative burst induced by T. harzianum as a signaling pathway

Chitosan (middle-viscous) as an effective elicitor for silymarin production in Silybum marianum hairy root cultures

Elicitation with middle-viscous chitosan (30 mg/50 mL) significantly stimulated silymarin synthesis in Silybum marianum hairy root cultures. The root cultures established by infection with Agrobacterium rhizogenes AR15834 showed a potential for production of silymarin. Elicitation with medium molecular weight of chitosan (0, 5, 10, 20, and 30 mg/50 mL) was used in order to improve silymarin production. Total silymarin increased about 5.26-fold after 96 h of treatment with 30 mg/50 mL chitosan. Dry weight of the hairy roots reached the highest point (0.530 and 0.535 g) after 96 h in presence of 20 and 30 mg/50 mL chitosan, respectively. Five different flavonolignans were isolated; taxifolin, silychristin, silydianin, silybin and isosilybin) 0.133, 0.200, 0.120, 0.041 and 0.056 mg/g dry weight, respectively). 30 days old hairy roots were treated by 30 mg/50 mL chitosan in different times (12, 24, 48, 72, 96 and 120 h). The amount of silymarin accumulation significantly increased (0.705 mg/gDW) in hairy roots after 96 h treatment. These observations suggested that the medium molecular weight of chitosan could be elicited by S. marianum hairy root cultures that lead to the higher production of silymarin. These results correlated with the culture time, and the biosynthesis which reached to a maximum of 0.705 mg/gDW by 96 h after culture. (2.9-fold higher than the control)