Accumulation of silymarin in milk thistle seeds under drought stress

Abstract

According to the results obtained in this study, drought stress can enhance the accumulation of silymarin in milk thistle seeds. Moreover, under drought stress, the share of silybin increased which possess the greatest degree of biological activity among the silymarin components. Silymarin, an isomeric mixture of flavonolignans found in milk thistle (Silybum marianum (L.) Gaertn) seeds, has been used for its hepatoprotective effects for more than 2,000 years. Biosynthesis and accumulation of active substances like silymarin in plant tissues highly interacts with the environmental conditions. Effects of moderate and severe drought stress (based on soil moisture depletion) on silymarin content and composition in milk thistle seeds were evaluated in a field study. Averaged across treatments, milk thistle seeds contained 19.3 g kg(-1) silymarin. Drought stress enhanced silymarin accumulation in milk thistle seeds. Plants grown under moderate and severe drought stress treatments contained 4 and 17 % greater silymarin than those grown in well-watered condition, respectively. Greater content of sylimarin in stressed plants was attributed to more contents of silybin, isosilybin and silychristin, while silydianin content was lower under drought condition. According to the results obtained in this study, drought stress enhanced accumulation of silymarin in milk thistle seeds and improved its quality by increasing the share of silybin, which possess the greatest degree of biological activity among the silymarin components.

Simple and Rapid HPLC Separation and Quantification of Flavonoid, Flavonolignans, and 2,3-Dehydroflavonolignans in Silymarin

“…Coniferyl alcohol (R t 1.6 min) was found in none of the silymarin preparations analyzed. In an agreement with the literature [27,30,31], reviewed in [7] and [18,19], the content of individual substances in silymarin preparations was found to vary considerably (Table 2, Figure 5).…”

Phenotypic Evaluation of a Milk Thistle Germplasm Collection: Fruit Morphology and Chemical Composition

“…The main difference is that in the chemotype A silydianin is almost absent. Significant differences in the silydianin content may derive from genotypic and environmental factors (Vömel et al, 1977;Adzet et al, 1987;Afshar et al, 2015b). Milk thistle genotypes with almost no silydianin were also described by Martin et al (2006) for accessions collected in New Zealand and by Cappelletti and Caniato (1984) for accessions collected in Italy.…”

“…A silydianin maximum content higher than 60 to 70% was previously reported by Vömel et al (1977) and by Adzet et al (1987). Significant differences in the silydianin content may derive from genotypic and environmental factors (Vömel et al, 1977;Adzet et al, 1987;Afshar et al, 2015b). been reported, this suggests that the biosynthetic pathway of these groups of molecules might not be completely independent as proposed by the sole extracellular peroxidase model.…”

Impact of Plant Density and Mepiquat Chloride on Growth, Yield, and Silymarin Content of Silybum marianum Grown under Mediterranean Semi-Arid Conditions

“…It is noteworthy to mention that the aboveground dry biomass in 2018 was 18.90% and 15.45% lower than that in 2016 for plant densities A and B, respectively. In a recent study Afshar et al [16] observed that the concentration of silymarin increased by 4% and 17% with water stress conditions. The results of our study showed that the silymarin yield declined in the second growing season of 2018 due to the lower productivity associated with drought conditions.…”