UPLC-MS/MS multivariate data analysis reveals phenological growth stages affect silymarin bioactive components of the different organs of two Silybum marianum genotypes

Microchemical Journal Volume 187, April 2023, 108436

A crucial subject which has been scarcely investigated is the variation in the relative amounts of the different components of the silymarin in the different organs as affected by the developmental stage. In this study, the effect of phenological growth stages on the accumulation dynamics of total and individual silymarin components in the different organs as well as anti-inflammatory activity of the two genotypes of Silybum marianum (L.) Gaertn.; purple and white flowers, was tracked. This was achieved by implementing targeted and untargeted chemical profiling of samples using Ultra Performance Liquid Chromatography hyphenated to mass spectrometry. Results revealed that silybin and silychristin accumulated mainly in the fruits, while the accumulation of silydianin was confined to the flowers of both genotypes. Isosilybin content was similar in the fruits, early drying stage leaves of white flowers genotype and leaves and fully expanded flowers of purple flowers genotype. Further, fruit extract of S. marianum purple flowers genotype possessed the most prominent anti-inflammatory activity, reducing the levels of Tumor necrosis factor alpha (TNF-α), Interleukin 1 beta (IL-1β) and Interferon gamma (INF-γ) comparable to Piroxicam. Substantial anti-inflammatory activity was also observed for the flowers and leaves collected in fruiting and the early drying stages. The coefficients plot of a constructed OPLS model revealed that silybin, silydianin and isosilybin were strongly correlated to the observed anti-inflammatory activity particularly INF-γ, reduction. Results highlight the flowers and leaves of post-fruiting early drying stage as unexploited S. marianum organs containing considerable amounts of specific silymarin components.