Exploration and optimization of conditions for quantitative analysis of lignans in Schisandra chinensis by an online supercritical fluid extraction with supercritical fluid chromatography system

Facilitated on-line supercritical fluid extraction - supercritical fluid chromatography for nonpolar and polar compounds from milk thistle seeds

Plant seeds, as those from milk thistle (Silybum marianum), are a valuable source of nonpolar and polar compounds with potentially interesting biological activity. The main nonpolar compounds are triglycerides, which are also the main components of all vegetable oils. In addition, specific polar compounds - flavonolignans, called silymarin, have been found in large amounts in milk thistle seeds extract. These flavonoids derivatives have different biological activity, for instance hepatoprotective effects. In order to extract and analyze both nonpolar (triglycerides) and polar compounds (flavonolignans) from milk thistle seeds through a sequential methodology, an on-line supercritical fluid extraction - supercritical fluid chromatography (SFE-SFC) method was developed. Different ways of transferring the extracts from SFE to SFC (i.e. direct on-column transfer and loop transfer) were compared, and particularly for their effect on chromatographic quality. In this respect, nonpolar and polar compounds caused different issues, especially as polar compounds required a significant portion of co-solvent in the extraction step, favoring early elution in the chromatographic column. First, on-line SFE-SFC was used for triglycerides analysis and allowed the comparison of transfer modes. Then, on-line kinetics were performed to measure defatting time before polar molecules extraction. Finally, the eventual benefit of loop transfer was also investigated for the analysis of flavonolignans, polar molecules whose analysis can be difficult by on-line SFE-SFC. The aim of this paper is to discuss the versatility of on-line SFE-SFC and how challenging the coupling can be, especially when both non-polar and polar molecules must be analyzed independently in a single sample.

Applications of Molecular Imprinting Technology in the Study of Traditional Chinese Medicine

Traditional Chinese medicine (TCM) is one of the most internationally competitive industries. In the context of TCM modernization and internationalization, TCM-related research studies have entered a fast track of development. At the same time, research of TCM is also faced with challenges, such as matrix complexity, component diversity and low level of active components. As an interdisciplinary technology, molecular imprinting technology (MIT) has gained popularity in TCM study, owing to the produced molecularly imprinted polymers (MIPs) possessing the unique features of structure predictability, recognition specificity and application universality, as well as physical robustness, thermal stability, low cost and easy preparation. Herein, we comprehensively review the recent advances of MIT for TCM studies since 2017, focusing on two main aspects including extraction/separation and purification and detection of active components, and identification analysis of hazardous components. The fundamentals of MIT are briefly outlined and emerging preparation techniques for MIPs applied in TCM are highlighted, such as surface imprinting, nanoimprinting and multitemplate and multifunctional monomer imprinting. Then, applications of MIPs in common active components research including flavonoids, alkaloids, terpenoids, glycosides and polyphenols, etc. are respectively summarized, followed by screening and enantioseparation. Related identification detection of hazardous components from TCM itself, illegal addition, or pollution residues (e.g., heavy metals, pesticides) are discussed. Moreover, the applications of MIT in new formulation of TCM, chiral drug resolution and detection of growing environment are summarized. Finally, we propose some issues still to be solved and future research directions to be expected of MIT for TCM studies.

A review of flaxseed lignan and the extraction and refinement of secoisolariciresinol diglucoside

Lignan is a class of diphenolic compounds that arise from the condensation of two phenylpropanoid moieties. Oilseed and cereal crops (e.g., flaxseed, sesame seed, wheat, barley, oats, rye, etc.) are major sources of plant lignan. Methods for commercial isolation of the lignan secoisolariciresinol diglucoside (SDG) are not well reported, as most publications describing the detection, extraction, and enrichment of SDG use methods that have not been optimized for commercial scale lignan recovery. Simply scaling up laboratory methods would require expensive infrastructure to achieve a marketable yield and reproducible product quality. Therefore, establishing standard protocols to produce SDG and its derivatives on an industrial scale is critical to decrease lignan cost and increase market opportunities. This review summarizes the human health benefits of flaxseed lignan consumption, lignan physicochemical properties, and mammalian lignan metabolism, and describes methods for detecting, extracting, and enriching flaxseed lignan. Refining and optimization of these methods could lead to the development of inexpensive lignan sources for application as an ingredient in medicines, dietary supplements, and other healthy ingredients.

Extraction Techniques and Analytical Methods for Isolation and Characterization of Lignans

Lignans are a group of natural polyphenols present in medicinal plants and in plants which are a part of the human diet for which more and more pharmacological activities, such as antimicrobial, anti-inflammatory, hypoglycemic, and cytoprotective, are being reported. However, it is their cytotoxic activities that are best understood and which have shed light on this group. Two anticancer drugs, etoposide, and teniposide, were derived from a potent cytotoxic agent—podophyllotoxin from the roots of Podophyllum peltatum. The evidence from clinical and observational studies suggests that human microbiota metabolites (enterolactone, enterodiol) of dietary lignans (secoisolariciresinol, pinoresinol, lariciresinol, matairesinol, syringaresinol, medioresinol, and sesamin) are associated with a reduced risk of some hormone-dependent cancers. The biological in vitro, pharmacological in vivo investigations, and clinical studies demand significant amounts of pure compounds, as well as the use of well-defined and standardized extracts. That is why proper extract preparation, optimization of lignan extraction, and identification are crucial steps in the development of lignan use in medicine. This review focuses on lignan extraction, purification, fractionation, separation, and isolation methods, as well as on chromatographic, spectrometric, and spectroscopic techniques for their qualitative and quantitative analysis.

Advanced Development of Supercritical Fluid Chromatography in Herbal Medicine Analysis

The greatest challenge in the analysis of herbal components lies in their variety and complexity. Therefore, efficient analytical tools for the separation and qualitative and quantitative analysis of multi-components are essential. In recent years, various emerging analytical techniques have offered significant support for complicated component analysis, with breakthroughs in selectivity, sensitivity, and rapid analysis. Among these techniques, supercritical fluid chromatography (SFC) has attracted much attention because of its high column efficiency and environmental protection. SFC can be used to analyze a wide range of compounds, including non-polar and polar compounds, making it a prominent analytical platform. The applicability of SFC for the separation and determination of natural products in herbal medicines is overviewed in this article. The range of applications was expanded through the selection and optimization of stationary phases and mobile phases. We also focus on the two-dimensional SFC analysis. This paper provides new insight into SFC method development for herbal medicine analysis.

Schisandrin B Attenuates Hepatic Stellate Cell Activation and Promotes Apoptosis to Protect against Liver Fibrosis

The activation of hepatic stellate cells (HSC) plays a key role in the progression of hepatic fibrosis, it is essential to remove activated HSC through apoptosis to reverse hepatic fibrosis. Schisandrin B (Sch B) is the main chemical component of schisandrin lignan, and it has been reported to have good hepatoprotective effects. However, Schisandrin B on HSC apoptosis remains unclear. In our study, we stimulated the HSC-T6 and LX-2 cell lines with TGF-β1 to induce cell activation, and the proliferation and apoptosis of the activated HSC-T6 and LX-2 cells were detected after treatment with different doses of Schisandrin B. Flow cytometry results showed that Sch B significantly reduced the activity of activated HSC-T6 and LX-2 cells and significantly induced apoptosis. In addition, the cleaved-Caspase-3 levels were increased, the Bax activity was increased, and the Bcl-2 expression was decreased in HSC-T6 and LX-2 cells treated with Sch B. Our study showed that Sch B inhibited the TGF-β1-induced activity of hepatic stellate cells by promoting apoptosis.

Study on the effect of active components of Schisandra chinensis on liver injury and its mechanisms in mice based on network pharmacology

The aim of this study was to analyze the active components of Schisandra chinensis on liver injury and its mechanism in mice by network pharmacology. The active components of S. chinensis were found through Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) and their corresponding targets were predicted. The targets of liver injury were searched through Therapeutic Targets Database (TTD), DisGeNET and drugbank databases, and the Venn diagram was constructed to obtain the action targets. The "drug-active component-target" network and protein-protein interaction network (PPI) were constructed by using STRING database and Cytoscape software, and the key targets were further screened by the enrichment analysis of relevant KEGG pathways. Finally, a CCl4-induced mouse liver injury model was established to verify the efficacy and related targets of S. chinensis and clarify its mechanism. Eight active components and 56 related targets of S. chinensis were screened out based on their oral bioavailability (OB) and drug likeness (DL). Five targets of S. chinensis related to liver injury were found by using the Venn diagram. The key targets, namely Ptgs2 and Nos2 genes, were further screened out by constructing a PPI network, and Schisandrol B (SCB) was considered the key component most closely related to the liver injury in S. chinensis. The results indicate that SCB may play a role in the treatment of the CCl4-induced liver injury by down-regulating the expression of iNOS and COX-2, and regulating the expression of NF-κB and IL-17 signaling pathway to inhibit the expression of proinflammatory factors.

Matrix Solid-Phase Dispersion Coupled with HPLC-UV for Simultaneous Extraction, Purification and Determination of Six Lignans in Schisandra chinensis Fruits

An efficient method for simultaneous extraction, purification and determination of six lignans in Schisandra chinensis Baill was developed by employing matrix solid-phase dispersion (MSPD) extraction followed by HPLC-UV determination analysis. Several sorbent and desorption solvent that affected the extraction yield of lignans were investigated; neutral alumina and absolute ethanol were selected as the best dispersing material and desorption agent, respectively. Other extraction conditions for MSPD were optimized as follows: 1:2 of S. chinensis raw material to neutral aluminum oxide mass ratio, 1:30 (g/mL) of sample to absolute ethanol, 2.5 h of desorption time and 50°C of desorption temperature. Under the above conditions, the total extraction yield for six lignans have reached (16.99 ± 0.33) x 103 mg/kg with a higher content of 6.88 ± 0.25% in the extracts. Comparative studies were explored by conducting other six extraction approaches including Soxhlet extraction, heat reflux extraction, smashing tissue extraction, microwave-assisted extraction, ultrasonic-assisted extraction and ultrasonic-microwave synergistic extraction. Results showed MSPD technique not only improved the extraction yield, but also improved the purity of lignans, it can be generalized to more extraction of natural compounds. In addition, the validated HPLC-UV method had been successfully applied to analysis of lignans from 10 real S. chinensis samples.

Schisandrin B-mediated TH17 cell differentiation attenuates bowel inflammation

Schisandrin B (Sch B) is the major active constituent of the traditional Chinese medicine Schisandra chinensis and has anti-inflammatory activity, but the target of Sch B remains unclear. T helper 17 (TH17) cells have been involved in the pathogenesis of many autoimmune and inflammatory diseases. Here, we showed that Sch B could decrease IL-17A production of CD4+ T cells by targeting STAT3 in vitro. Importantly, Sch B has therapeutic effects on DSS-induced acute and chronic colitis, CD4+CD45RBhigh T cell-induced colitis. Furthermore, we identified TH17 cells as the direct target of Sch B for mediating its anti-inflammatory activity. Sch B could serve as a lead for developing new therapeutics against TH17 cells or IL-17A cytokine-driven diseases.

Investigation of the active components and mechanisms of Schisandra chinensis in the treatment of asthma based on a network pharmacology approach and experimental validation

The aim of this paper was to investigate the active components of Schisandra chinensis in the treatment of asthma and the related mechanisms by a network pharmacology approach. The active components of Schisandra chinensis and the corresponding targets were obtained from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP). Eight active components in Schisandra chinensis and 56 related targets were screened out according to two indicators, oral bioavailability (OB) and drug-likeness (DL). A total of 132 targets related to asthma were screened out through Therapeutic Target Database (TTD) data. The String database and Cytoscape software were used to build the "drug-active compound-target" network and protein-protein interaction (PPI) network. The key targets were further predicted by the analysis of related biological processes and the pathway-enrichment. A total of 10 intersection targets between Schisandra chinensis and asthma were obtained by building Venn diagrams, and lignans in Schisandra chinensis were found to be associated with asthma. The key targets Ptgs2 and Nos2 were further screened out, and schisandrol B (SCB) was predicted as the most related key component to asthma. A mouse asthma model was established with ovalbumin and aluminum hydroxide for verifying the effect of SCB and related mechanisms. The results showed that SCB could inhibit the gene expression of proinflammatory factors to play a therapeutic role in asthma by reducing the expression of Nos2 and Ptgs2 and regulating the NF-κB signaling pathway to intervene in the process of cell metabolism in mice. These results suggest that SCB can alleviate the severity of asthma through the mechanisms predicted by network pharmacology, and provide a basis for further understanding of the application of Schisandra chinensis in the treatment of asthma.

Schisandrin B regulates MC3T3-E1 subclone 14 cells proliferation and differentiation through BMP2-SMADs-RUNX2-SP7 signaling axis

Schisandrin B (SchB) is the highest content of biphenyl cyclooctene lignans in Schisandra chinensis. It has been reported to have a variety of pharmacological effects, including anti-inflammatory, anti-oxidant, anti-cancer, heart protection, liver protection. In this study, we found that SchB can promote the proliferation of MC3T3-E1 subclone 14 cells. Meanwhile, we found that SchB can regulate the BMP2-SMADs signaling pathway by increasing gene and protein expression of those relative biomolecules. Furthermore, SchB can raise the RUNX2 and SP7 expression in both mRNA and protein levels. Since the role of BMP2-SMADs-RUNX2-SP7 signaling axis in osteoblast proliferation and differentiation has been well documented. The present experimental findings indicate that SchB could promote the proliferation and differentiation of osteoblasts through BMP2-SMADs-RUNX2-SP7 signaling axis.