Detecting and Profiling of Milk Thistle Metabolites in Food Supplements: A Safety-Oriented Approach by Advanced Analytics

Exploring Silybum marianum L. seeds from Pakistan for its antibacterial, antioxidant, antidiabetic activities, and phytochemical analysis

In this study, various extracts, including methanol (SMLM), hydro-ethanol (SMLE), n-hexane (SMLH), and aqueous (SMLA) were formulated from the seeds of Silybum marianum L. and subjected to phytochemical assessment, HPLC, FTIR analysis, and different in vitro bioassays. The qualitative analysis revealed the presence of all representative groups, except alkaloids, in the samples. The quantitative examination indicated that the SMLE extract exhibited the highest total flavonoid contents and highest entire phenolic concentrations. HPLC analysis of the SMLM extract identified chlorogenic acid, gallic acid, kaempferol, benzoic acid and HB acid which were reported for the first time from S. marianum. In terms of antibacterial activity, the SMLH extract demonstrated a significant zone of inhibition (34 ± 0.5 mm) against Gram-positive bacterial species, Staphylococcus aureus. In antioxidant assays, the SMLM extract displayed the highest scavenging potential against DPPH radicals and exhibited a significant IC50 of 4.8 ± 1.2 μg/mL, indicating notable efficacy. Subsequently, the SMLE extract demonstrated an IC50 of 20.17 ± 0.4 μg/mL. In the context of antidiabetic evaluation, the SMLM extract displayed the highest effectiveness, revealing an IC50 value of 5.2 ± 0.07 μg/mL. To conclude, the assessed samples, such as the SMLM and SMLE extracts, exhibit remarkable capabilities in the studied activities, potentially attributed to the existence of bioactive compounds.

Silymarin targets the FXR protein through microbial metabolite 7-keto-deoxycholic acid to treat MASLD in obese mice

BACKGROUND

Silymarin is recognized for its excellent hepato-protective properties. Recent clinical studies have examined the effects of silymarin on metabolic dysfunction-associated steatotic liver disease (MASLD), highlighting the necessity of further exploration into optimal dosages, active components, and mechanisms of action.

METHODS AND RESULTS

This study assessed the anti-inflammatory activity of the principal constituents of silymarin at the cellular level. The therapeutic effects of varying silymarin doses and components on MASLD in mouse models induced by a high-fat diet (HFD) were also examined. These findings indicate the superior efficacy of 80 mg kg-1 silymarin in mitigating liver steatosis and reducing lipid accumulation compared to 30 mg kg-1 silymarin or a combination of silybin and isosilybin A. The mechanism of silymarin involves regulating gut microbiota homeostasis and influencing the TLR4/NF-κB signalling pathway through LPS. Bile acid-targeted metabolomics analysis revealed that silymarin significantly decreases the HFD-induced increase in 7-keto-deoxycholic acid (7-KDCA). Further investigations suggested that 7-KDCA as an antagonist targeted farnesoid X receptor (FXR) and that both silybin and isosilybin A could directly interact with FXR.

CONCLUSION

These findings elucidate that 80 mg kg-1 of silymarin can exert therapeutic effects on MASLD mice and offer novel insights into the mechanism of silymarin in treating MASLD. Especially, it was found that silymarin could regulate bile acid metabolism, reduce the concentration of 7-KDCA, and thus perform negative feedback regulation on FXR.

In Search of Authenticity Biomarkers in Food Supplements Containing Sea Buckthorn: A Metabolomics Approach

Sea buckthorn (Hippophae rhamnoides L.) (SB) is increasingly consumed worldwide as a food and food supplement. The remarkable richness in biologically active phytochemicals (polyphenols, carotenoids, sterols, vitamins) is responsible for its purported nutritional and health-promoting effects. Despite the considerable interest and high market demand for SB-based supplements, a limited number of studies report on the authentication of such commercially available products. Herein, untargeted metabolomics based on ultra-high-performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry (UHPLC-QTOF-ESI+MS) were able to compare the phytochemical fingerprint of leaves, berries, and various categories of SB-berry herbal supplements (teas, capsules, tablets, liquids). By untargeted metabolomics, a multivariate discrimination analysis and a univariate approach (t-test and ANOVA) showed some putative authentication biomarkers for berries, e.g., xylitol, violaxanthin, tryptophan, quinic acid, quercetin-3-rutinoside. Significant dominant molecules were found for leaves: luteolin-5-glucoside, arginine, isorhamnetin 3-rutinoside, serotonin, and tocopherol. The univariate analysis showed discriminations between the different classes of food supplements using similar algorithms. Finally, eight molecules were selected and considered significant putative authentication biomarkers. Further studies will be focused on quantitative evaluation.

Authentication of milk thistle commercial products using UHPLC-QTOF-ESI + MS metabolomics and DNA metabarcoding

BACKGROUND

Milk thistle is one of the most popular hepatoprotectants, and is often sold in combination with other ingredients. Botanical supplements are known to be vulnerable to contamination and adulteration, and emerging technologies show promise to improve their quality control.

METHODS

Untargeted and semi-targeted metabolomics based on UHPLC-QTOF-ESI⁺MS techniques, UV spectrometry, and DNA metabarcoding using Illumina MiSeq were used to authenticate eighteen milk thistle botanical formulations (teas, capsules, tablets, emulsion).

RESULTS

Untargeted metabolomics separated 217 molecules and by multivariate analysis the discrimination between the different preparations was established. The semi-targeted metabolomics focused on 63 phytochemicals, mainly silymarin flavonolignans and flavonoids, that may be considered as putative biomarkers of authenticity. All formulations contained molecules from silymarin complexes at different levels. The quantitative evaluation of silybins was done using in parallel UV spectrometry and UHPLC-QTOF-ESI⁺MS and their correlations were compared. DNA metabarcoding detected milk thistle in eleven out of sixteen retained preparations, whereas two others had incomplete evidence of milk thistle despite metabolomics validating specific metabolites, e.g., silymarin complex, identified and quantified in all samples. Meanwhile, the DNA metabarcoding provided insights into the total species composition allowing the interpretation of the results in a broad context.

CONCLUSION

Our study emphasizes that combining spectroscopic, chromatographic, and genetic techniques bring complementary information to guarantee the quality of the botanical formulations.