Effects of Different Extraction Methods and Solvents on the Phenolic Composition and Antioxidant Activity of Silybum Marianum Leaves Extracts

Abstract

Objective: The objectives of this study were essentially to evaluate the best technique for extracting phenolic compounds from Silybum marianum leaves.
 Subjects and Methods: Two extraction methods (maceration and decoction), using four extraction solvents. The efficiency of the extraction methods was estimated by quantifying the total polyphenol contents by the Folin -Ciocalteu method and by determining the antioxidant power of the various extracts by the ability to trap the free radical DPPH °, and the influence of these parameters on the antioxidant activity.
 Results: The results showed that the extracts of the leaves by maceration have contained the highest percentage yield (24.68%); the highest content in the aqueous -methanol polyphenols extract (18.75 ± 0.55 mg GAE / g DW ) against the decoction is more effective for the extraction of flavonoids and condensed tannins. The highest content of flavonoids had been recorded for the aqueous- ethanolic extract (5.08 ± 0.57 CE mg / g DW). The water had the highest content of condensed tannin (03.86 ± 0.22 TAE / g DW). On the other hand, the aqueous -ethanolic and aqueous -methanol extract of the leaves obtained by maceration have the best antioxidant capacity (73.84 ± 5.90 EAG / g DW and 73.64 ± 5.93 mg EAG / g DW respectively) and the aqueous extract of the leaves by decoction had a better antiradical power (48.64 μg / ml).
 Conclusion: The extraction of phenolic compounds from Silybum marianum leaves was strongly influenced by the type of solvent and the extraction method. In addition, it is very difficult to choose an appropriate extraction solvent for all plant samples.

Bioactive Compounds from Leaves and Twigs of Guayule Grown in a Mediterranean Environment

“…populations were studied for chemical and productive properties by Sulas et al [19] reporting, in acetone/water leaves extract, a content of antioxidant capacity (7.6 mmol TEAC 100 g −1 DW) and total flavonoids (11.5 g CE kg −1 DW) lower than our results. A content of phenolic compounds lower (18.7 mg GAE g −1 DW) than our results was also reported by Benchaachoua et al [25] in a aqueous-methanol extract of leaves of S. marianum collected in Algeria. Ben Salem et al [26] found phenolic contents of artichoke (Cynara scolymus L.) leaves extracts from 39.9 to 54.5 mg GAE g −1 DW lower than our results.…”

Antifungal Activity against Botryosphaeriaceae Fungi of the Hydro-Methanolic Extract of Silybum marianum Capitula Conjugated with Stevioside

“…The concentration of silymarin is organ-dependent, and it is only localized in the outer portion of the fruit, which includes all the cell layers from the pericarp epidermis to the albumen, and embryos [6], accounting for 1.5-4.3% of the fruit weight [7]. Silymarin is not present in flowers, stems, or leaves, and it is not found in steps before the development of fruit [8,9], which explains why other milk thistle plant organs have been scarcely investigated for bioactive compounds: total polyphenol and flavonoid contents in leaves' extracts were studied by Saidi, et al [10]; a phytochemical screening and gas chromatography-mass spectrometry (GC-MS) analysis of bioactive compounds present in ethanolic leaves extract was conducted by Mani, et al [11]; and Sulas, et al [12] studied the concentrations of crude protein, fat, total phenolics, and total flavonoids in leaves, heads, and stems.…”

Tannins: Extraction from Plants

“…The mixture is then cooled to room temperature and the filtrate collection. Aqueous is a good solvent for the extraction of condensed tannins by decoction and maceration [32]. The decoction is very suitable for non-destroyed substances by the heat [31].…”