Chemical and productive properties of two Sardinian milk thistle (Silybum marianum (L.) Gaertn.) populations as sources of nutrients and antioxidants

Abstract

Silybum marianum (L.) Gaertn. (milk thistle), grown as a medicinal plant in several countries, is considered as a weed in pastures and cereal crops but also as an interesting plant for biomass production. As an additional contribution to the full exploitation of a such promising species, two Sardinian populations of S. marianum were investigated for chemical composition, bioactive compounds and antioxidant properties at vegetative and reproductive stages. Dry matter yield was affected by the phenogical stage and differed between populations, ranging from 148 to 246 g plant -1 . Chemical composition did not differ between populations. Antioxidant capacity detected by means of ABTS [(2,2 0 -azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt)] and by DPPH (1,1-diphenyl-2-picrylhydrazyl) methods ranged from 3.45 to 5.42 and 3.83 to 6.32 mmol/ 100 g dry weight of Trolox equivalent antioxidant capacity, respectively. Differences in antioxidant capacity and bioactive compound contents in the different plant organs were found and also a significant linear correlation between antioxidant capacity and total phenolics and flavonoids, at flowering compared to vegetative stage. Research highlights antioxidant capacity in different organs of milk thistle and encourages the exploitation of biomass also as functional food, source of natural antioxidants and as a complementary fodder.

Polyphenolic composition and antioxidant capacity of legume‐based swards are affected by light intensity in a Mediterranean agroforestry system

“…Significant correlations were also found between antioxidant capacity and TotP and TotF in both FS and PS. Our findings agree with many studies regarding the relationship between antioxidant activity and total phenolic compounds …”

“…Among plant secondary metabolites, phenolics are a class of commonly‐found bioactive compounds, which includes several groups of different substances. Phenolic acids, flavonoids and tannins are the most important compounds as a result of their biological activities, and especially their antioxidant properties and related implications in animal nutrition and welfare . Levels of plant antioxidants vary as a result of temperature, light intensity, harvesting season and genetic factors .…”

Phytochemical profile of Silybum marianum (L.) Gaertn. and Graminis rhizoma and its influence on the bioactivity and shelf life of industrially produced pâté

“…However, it was also noted that, in general, the extent of ABTS and DPPH inhibition for almost all samples significantly ( P < 0.001) increased from day 1 to day 21. Our data are consistent with the observations of many studies that documented the relationship between antioxidant activity and total phenolic compounds (Pereira et al ., ; Mhamdi et al ., ; Sulas et al ., ). The pâté sample fortified with S. marianum seeds contains powerful inhibitor compounds, especially silymarin, which being an efficient hydrogen donor may act as a primary antioxidant by reacting with free radicals.…”

Weed infestation in the stand of milk thistle and infestation in sustainable crop rotation

“…-milk thistle -grown as a medicinal plant in several countries, is considered as a weed in pastures and cereal crops but also as an interesting plant for biomass production. As an additional contribution to the full exploitation of such promising species, two Sardinian populations of Silybum marianum were investigated for chemical composition, bioactive compounds and antioxidant properties at vegetative and reproductive stages (Sulas et al, 2015).…”

“…-milk thistle -grown as a medicinal plant in several countries, is considered as a weed in pastures and cereal crops but also as an interesting plant for biomass production. As an additional contribution to the full exploitation of such promising species, two Sardinian populations of Silybum marianum were investigated for chemical composition, bioactive compounds and antioxidant properties at vegetative and reproductive stages (Sulas et al, 2015).According to Carpino et al (2003), milk thistle, as spontaneous weed, is scarcely consumed by large and small ruminants grazing on Mediterranean pastures but an increased animal preference has been observed in Sardinia by local farmers when milk thistle is harvested as silage or hay (Sanna S, pers. comm.).…”