An improved method for the isolation of amarogentin, the bitter principle of yellow gentian roots

Integrated serum metabolomics, 16S rRNA sequencing and bile acid profiling to reveal the potential mechanism of gentiopicroside against nonalcoholic steatohepatitis in lean mice

ETHNOPHARMACOLOGICAL RELEVANCE

Lean nonalcoholic steatohepatitis (NASH) poses a serious threat to public health worldwide. Herbs of the genus Gentiana have been used for centuries to treat hepatic disease or have been consumed for hepatic protection efficiency. Gentiopicroside (GPS), the main bioactive component of Gentiana herbs, has been shown to be beneficial for protecting the liver, improving intestinal disorders, modulating bile acid profiles, ameliorating alcoholic hepatosteatosis, and so on. It is plausible to speculate that GPS may hold potential as a therapeutic strategy for lean NASH. However, no related studies have been conducted thus far.

AIM OF THE STUDY

The present work aimed to investigate the benefit of GPS on NASH in a lean mouse model.

MATERIALS AND METHODS

NASH in a lean mouse model was successfully established via a published method. GPS of 50 and 100 mg/kg were orally administered to verify the effect. Untargeted metabolomics, 16S rDNA sequencing and bile acid (BA) profiling, as well as qPCR and Western blotting analysis were employed to investigate the mechanism underlying the alleviating effect.

RESULTS

GPS significantly reduced the increase in serum biochemicals and liver index, and attenuated the accumulation of fat in the livers of lean mice with NASH. Forty-two potential biomarkers were identified by metabolomics analysis, leading to abnormal metabolic pathways of primary bile acid biosynthesis and fatty acid biosynthesis, which were subsequently rebalanced by GPS. A decreased Firmicutes/Bacteroidetes (F/B) ratio and disturbed BA related GM profiles were revealed in lean mice with NASH but were partially recovered by GPS. Furthermore, serum profiling of 23 BAs confirmed that serum BA levels were elevated in the lean model but downregulated by GPS treatment. Pearson correlation analysis validated associations between BA profiles, serum biochemical indices and related GM. qPCR and Western blotting analysis further elucidated the regulation of genes associated with liver lipid synthesis and bile acid metabolism.

CONCLUSIONS

GPS may ameliorate steatosis in lean mice with NASH, regulating the metabolomic profile, BA metabolism, fatty acid biosynthesis, and BA-related GM. All these factors may contribute to its beneficial effect.

Bitter Phytochemicals as Novel Candidates for Skin Disease Treatment

Skin diseases represent a global healthcare challenge due to their rising incidence and substantial socio-economic burden. While biological, immunological, and targeted therapies have brought a revolution in improving quality of life and survival rates for certain dermatological conditions, there remains a stringent demand for new remedies. Nature has long served as an inspiration for drug development. Recent studies have identified bitter taste receptors (TAS2Rs) in both skin cell lines and human skin. Additionally, bitter natural compounds have shown promising benefits in addressing skin aging, wound healing, inflammatory skin conditions, and even skin cancer. Thus, TAS2Rs may represent a promising target in all these processes. In this review, we summarize evidence supporting the presence of TAS2Rs in the skin and emphasize their potential as drug targets for addressing skin aging, wound healing, inflammatory skin conditions, and skin carcinogenesis. To our knowledge, this is a pioneering work in connecting information on TAS2Rs expression in skin and skin cells with the impact of bitter phytochemicals on various beneficial effects related to skin disorders.

Separation and quantification of Tartrazine (E102) and Brilliant Blue FCF (E133) in green colored foods and beverages

In the present study we investigated the capacities of a panel of 25 solid sorbents represented by layered structures, inorganic oxides and hydroxides, and phyllosilicates, to effectively remove in high yield Tartrazine (E102) and Brilliant Blue FCF (E133) from aqueous solutions, and more notable, green colored food matrices. Quantification of the title compounds have been achieved by HPLC-DAD analyses. Contents of E102 and E133 in real samples were in the range 1.3-36.5 μg/mL and 1.0-20.1 μg/mL, respectively. After a treatment of 1 min., in most cases a complete bleaching of solutions and deep coloring of the solid phase was recorded. The most effective solids to this aim were seen to be aluminium based ayered double hydroxides. In the case of magnesium oxide for E102, and magnesium aluminium D. benzensulfonate SDS 01 H8L and Florisil for E133, a selective adsorption (>99.9 %) of only one dye was observed. The adsorption recorded was strictly dependent on the loading of the sorbent. Related values were 300 mg for the separation of E102 by magnesium oxide from all the five food matrices under investigation, and in the range 200 mg-300 mg for magnesium aluminium D. benzensulfonate SDS 01 H8L and Florisil in the case of E133. The application of Langmuir and Freundlich models suggested that the adsorption may take place in the inner layers of the solids with a favourable thermodynamique outcome. Findings described herein offer the concrete possibility of quantifications of individual dyes in matrices containing more than one food colorant.

Solid-phase adsorption methodologies of naturally occurring anthraquinones: A review

INTRODUCTION

Solid-phase extraction applied to plant matrices is nowadays a well-validated technique allowing to concentrate and purify different secondary metabolites. Several classes of phytochemicals have been selectively extracted by this methodology. During the last decade attention has been focused on biologically active anthraquinones from numerous sources like edible, healthy, and medicinal plants.

OBJECTIVES

The aim of this review is to provide a detailed literature survey of the solid-phase adsorption methodologies for the extraction of natural anthraquinones reported so far and to discuss and propose future directions in this field of research.

MATERIALS AND METHODS

Substructure search was performed in the SciFinder Scholar, PubMed, Medline, and Scopus databases.

RESULTS

The first report about application of solid-phase adsorption for the purification of anthraquinones appeared in the literature in 2002. From this date, and in particular during recent years, the most notable examples included the use of chitin- and chitosan-based polymers, of molecularly imprinted polymers, of coated magnetic nanoparticles, of miniaturized matrix solid-phase dispersion, of functionalized resins, of differently structured lamellar solids, and finally of vortex-synchronized matrix solid-phase dispersion.

CONCLUSIONS

The herein detailed solid-phase adsorption methodologies are powerful tools to selectively extract natural anthraquinones and/or provide anthraquinone-enriched phytopreparations. Nevertheless, many other important methods have been applied to synthetic anthraquinones (e.g., azo dyes). These could be conveniently employed also for natural anthranoids. Studies in this field are discussed in this review article.

Leaves of Yellow Gentian (Gentiana lutea) as an Alternative Source of Bitter Secoiridoid Glycosides

In a search for methods of manufacturing bitter principles from Gentiana lutea, mainly represented by gentiopicroside (1) and amarogentin (2), as an alternative to extraction from the roots of this plant, in this short communication it is shown that the leaves of this plant can be regarded as an additional source of such phytochemicals. Extraction of G. lutea leaves was coupled to solid-phase adsorption by differently structured solids as a separation technology step, providing a selective isolation of both these secondary metabolites in good to excellent yields. Thus, the extraction of bitter secoiridoids can be achieved in an equivalent or improved way rather than processing the roots of G. lutea while preserving the biodiversity of the species.

An easy way for the hydrolysis, pre-concentration, and chemical stabilization of crocetin from saffron powder

To date there are no methods in the literature leading to crocetin selective concentration from saffron powder aqueous solutions. To this aim, we decided to test the performance of its heterogeneous extraction by means of a panel of 21 synthetic clays, 4 of which demonstrated to selectively retain crocetin in the solid phase after hydrolysis of its digentiobyosil ester (crocin) (and its isomers) and to its chemical stabilization (e.g., oxidation) over time. The best adsorption yield was obtained with zinc hydroxy chloride (66.18 ± 0.06 μg/g dry powder). This phenomenon was assessed by HPLC-DAD analyses after desorption of crocetin from the respective support and assessing its degradation along a period of 30 days. The method we established could represent a good mean to provide pure crocetin from saffron powder, preserving in the meantime its chemical properties for a concrete future exploitation for food pharmaceutical, and cosmetic purposes.