Protic Ionic Liquids as Efficient Solvents in Microwave-Assisted Extraction of Rhein and Emodin from Rheum palmatum L

Assembly and network of Rhei Radix et Rhizoma surface microbiome shaped by processing methods and sampling locations

Objective

Rhei Radix et Rhizoma has five types of products, namely, raw rhubarb (RR), wine rhubarb (WR), vinegar rhubarb (VR), cooked rhubarb (CR), and rhubarb charcoal (RC). However, Rhei Radix et Rhizoma is easily contaminated with fungi and mycotoxins if not harvested or processed properly. Here, we intend to analyze how microbiome assemblies and co-occurrence patterns are influenced by sampling locations and processing methods.

Methods

High-throughput sequencing and internal transcribed spacer 2 (ITS2) were carried out to study the diversities (α- and β-diversity), composition (dominant taxa and potential biomarkers), and network complexitity of surface fungi on RR, WR, VR, CR, and RC collected from Gansu and Sichuan provinces, China.

Results

The phyla Ascomycota and Basidiomycota; the genera Kazachstania, Malassezia, and Asterotremella; and the species Kazachstania exigua, Asterotremella pseudolonga, and Malassezia restricta were the dominant fungi and exhibited differences in the two provinces and the five processed products. The α-diversity and network complexity were strongly dependent on processing methods. Chao 1, the Shannon index, and network complexity and connectivity were highest in the CR group. The α-diversity and network complexity were influenced by sampling locations. Chao 1 and network complexity and connectivity were highest in the Gansu Province.

Conclusion

The assembly and network of the surface microbiome on Rhei Radix et Rhizoma were shaped by processing methods and sampling locations. This paper offers a comprehensive understanding of microorganisms, which can provide early warning for potential mycotoxins and ensure the safety of drugs and consumers.

Rhein: An Updated Review Concerning Its Biological Activity, Pharmacokinetics, Structure Optimization, and Future Pharmaceutical Applications

Rhein is a natural active ingredient in traditional Chinese medicine that has attracted much attention due to its wide range of pharmacological activities. However, its clinical application is limited by low water solubility, poor oral absorption, and potential toxicity to the liver and kidneys. Recently, advanced extraction and synthesis techniques have made it possible to develop derivatives of rhein, which have better pharmacological properties and lower toxicity. This article comprehensively summarizes the biological activity and action mechanism of rhein. Notably, we found that TGF-β1 is the target of rhein improving tissue fibrosis, while NF-κB is the main target of its anti-inflammatory effect. Additionally, we reviewed the current research status of the pharmacokinetics, toxicology, structural optimization, and potential drug applications of rhein and found that the coupling and combination therapy of rhein and other active ingredients exhibit a synergistic effect, significantly enhancing therapeutic efficacy. Finally, we emphasize the necessity of further studying rhein's pharmacological mechanisms, toxicology, and development of analogs, aiming to lay the foundation for its widespread clinical application as a natural product and elucidate its prospects in modern medicine.

The phytochemistry and pharmacology of three Rheum species: A comprehensive review with future perspectives

BACKGROUND

Rheum palmatum, R. tanguticum, and R. officinale, integral species of the genus Rheum, are widely used across global temperate and subtropical regions. These species are incorporated in functional foods, medicines, and cosmetics, recognized for their substantial bioactive components.

PURPOSE

This review aims to synthesize developments from 2014 to 2023 concerning the botanical characteristics, ethnopharmacology, nutritional values, chemical compositions, pharmacological activities, mechanisms of action, and toxicity of these species.

METHODS

Data on the three Rheum species were gathered from a comprehensive review of peer-reviewed articles, patents, and clinical trials accessed through PubMed, Google Scholar, Web of Science, and CNKI.

RESULTS

The aerial parts are nutritionally rich, providing essential amino acids, fatty acids, and minerals, suitable for use as health foods or supplements. Studies have identified 143 chemical compounds, including anthraquinones, anthrones, flavonoids, and chromones, which contribute to their broad pharmacological properties such as laxative, anti-diarrheal, neuroprotective, hepatoprotective, cardiovascular, antidiabetic, antitumor, anti-inflammatory, antiviral, and antibacterial effects. Notably, the materials science approach has enhanced understanding of their medicinal capabilities through the evaluation of bioactive compounds in different therapeutic contexts.

CONCLUSION

As medicinal and economically significant herb species, Rheum species provide both edible aerial parts and medicinal underground components that offer substantial health benefits. These characteristics present new opportunities for developing nutritional ingredients and therapeutic products, bolstering the food and pharmaceutical industries.

Antiviral, antioxidant, and anti-inflammatory activities of rhein against white spot syndrome virus infection in red swamp crayfish (Procambarus clarkii)

IMPORTANCE

Aquaculture is essential for ensuring global food security by providing a significant source of animal protein. However, the spread of the white spot syndrome virus (WSSV) has resulted in considerable economic losses in crustacean industries. In this study, we evaluated the antiviral activity of rhein, the primary bioactive component of Rheum palmatum L., against WSSV infection, and many pathological aspects of WSSV were also described for the first time. Our mechanistic studies indicated that rhein effectively arrested the replication of WSSV in crayfish by modulating innate immunity to inhibit viral gene transcription. Furthermore, we observed that rhein attenuated WSSV-induced oxidative and inflammatory stresses by regulating the expression of antioxidant and anti-inflammatory-related genes while enhancing innate immunity by reducing total protein levels and increasing phosphatase activity. Our findings suggest that rhein holds great promise as a potent antiviral agent for the prevention and treatment of WSSV in aquaculture.

Natural Products: A Dependable Source of Therapeutic Alternatives for Inflammatory Bowel Disease through Regulation of Tight Junctions

Inflammatory bowel disease (IBD), which includes Crohn's disease (CD) and ulcerative colitis (UC), can affect the entire gastrointestinal tract and mucosal layer and lead to intestinal damage and intestinal dysfunction. IBD is an inflammatory disease of the gastrointestinal tract that significantly impacts public health development. Monoclonal antibodies and other synthetic medications are currently used to treat IBD, but they are suspected of producing serious side effects and causing a number of other problems with long-term use. Numerous in vitro and in vivo studies have shown that organic macromolecules from plants and animals have an alleviating effect on IBD-related problems, and many of them are also capable of altering enzymatic function, reducing oxidative stress, and inhibiting the production of cytokines and release of proinflammatory transcriptional factors. Thus, in this paper, the natural products with potential anti-IBD activities and their mechanism of action were reviewed, with a focus on the protective effects of natural products on intestinal barrier integrity and the regulation of tight junction protein expression and remodeling. In conclusion, the insights provided in the present review will be useful for further exploration and development of natural products for the treatment of IBD.

Advances of Imidazolium Ionic Liquids for the Extraction of Phytochemicals from Plants

In this review, we present the research from 2013 to 2022 about the character of ionic liquids, the categories of phytochemicals, and the reasons for selecting imidazolium ionic liquids for phytochemical extraction. Then we introduce the structural formulae of the imidazolium ionic liquids commonly used in the extraction of phytochemicals, the methods used to prepare imidazolium ionic liquids, and a comprehensive introduction of how imidazolium ionic liquids are applied to extract phytochemicals from plants. Importantly, we discuss the strategies for studying the extraction mechanisms of imidazolium ionic liquids to extract phytochemicals, and the recovery methods regarding imidazolium ionic liquids and their recyclability are analyzed. Then the toxicity in imidazolium ionic liquids is pointed out. Finally, the challenges and prospects of extracting phytochemicals by imidazolium ionic liquids are summarized, and they are expected to provide some references for researchers.

Rhein for treating diabetes mellitus: A pharmacological and mechanistic overview

With the extension of life expectancy and changes in lifestyle, the prevalence of diabetes mellitus is increasing worldwide. Rheum palmatum L. a natural botanical medicine, has been used for thousands of years to prevent and treat diabetes mellitus in Eastern countries. Rhein, the main active component of rhubarb, is a 1, 8-dihydroxy anthraquinone derivative. Previous studies have extensively explored the clinical application of rhein. However, a comprehensive review of the antidiabetic effects of rhein has not been conducted. This review summarizes studies published over the past decade on the antidiabetic effects of rhein, covering the biological characteristics of Rheum palmatum L. and the pharmacological effects and pharmacokinetic characteristics of rhein. The review demonstrates that rhein can prevent and treat diabetes mellitus by ameliorating insulin resistance, possess anti-inflammatory and anti-oxidative stress properties, and protect islet cells, thus providing a theoretical basis for the application of rhein as an antidiabetic agent.

Emodin in cardiovascular disease: The role and therapeutic potential

Emodin is a natural anthraquinone derivative extracted from Chinese herbs, such as Rheum palmatum L, Polygonum cuspidatum, and Polygonum multiflorum. It is now also a commonly used clinical drug and is listed in the Chinese Pharmacopoeia. Emodin has a wide range of pharmacological properties, including anticancer, antiinflammatory, antioxidant, and antibacterial effects. Many in vivo and in vitro experiments have demonstrated that emodin has potent anticardiovascular activity. Emodin exerts different mechanisms of action in different types of cardiovascular diseases, including its involvement in pathological processes, such as inflammatory response, apoptosis, cardiac hypertrophy, myocardial fibrosis, oxidative damage, and smooth muscle cell proliferation. Therefore, emodin can be used as a therapeutic drug against cardiovascular disease and has broad application prospects. This paper summarized the main pharmacological effects and related mechanisms of emodin in cardiovascular diseases in recent years and discussed the limitations of emodin in terms of extraction preparation, toxicity, and bioavailability-related pharmacokinetics in clinical applications.

Recent advances in poly(ionic liquid)s for biomedical application

Poly(ionic liquid)s (PILs) are polymers containing ions in their side-chain or backbone, and the designability and outstanding physicochemical properties of PILs have attracted widespread attention from researchers. PILs have specific characteristics, including negligible vapor pressure, high thermal and chemical stability, non-flammability, and self-assembly capabilities. PILs can be well combined with advanced analytical instruments and technology and have made outstanding contributions to the development of biomedicine aiding in the continuous advancement of science and technology. Here we reviewed the advances of PILs in the biomedical field in the past five years with a focus on applications in proteomics, drug delivery, and development. This paper aims to engage pharmaceutical and biomedical scientists to full understand PILs and accelerate the progress from laboratory research to industrialization.

Ultrasound-assisted deep eutectic solvents extraction of glabridin and isoliquiritigenin from Glycyrrhiza glabra: Optimization, extraction mechanism and in vitro bioactivities

Licorice (Glycyrrhiza glabra) is extensively used owing to the superior pharmacological effects. However, its maximum application potential has not been fully exploited due to the limitation of currently available extraction solvent and methods. In this study, an eco-friendly deep eutectic solvent (NADESs) based ultrasound-assisted extraction (DES-UAE) method was applied to prepare licorice extracts. The DES-UAE using choline chloride and lactic acid as solvent was optimized and modeled by using response surface methodology to maximize the extraction yields of glabridin (GLA) and isoliquiritigenin (ISL). The optimized extracts possessed higher contents of GLA and ISL than available extraction methods, and the enriched products showed superior pharmacological activities in vitro. Furthermore, scanning electron microscopy (SEM) and molecular dynamic simulation analyses were performed to deeply investigate the interaction between solvent and targeted compounds. This study not only provides an eco-friendly method for high-efficient extraction of GLA and ISL from licorice but also illustrates the mechanism of the increased extraction efficacy, which may contribute to the application of licorice and deep insight into extraction mechanism using DES.

Therapeutic effects of Chinese herbal medicines and their extracts on diabetes

With the improvement of people's living standards and changes in the environment, the incidence of diabetes has increased rapidly. It has gradually become one of the main diseases threatening the health and life of modern people, bringing a great burden to the society. Although the existing treatment methods can effectively control the symptoms of diabetes and delay its progression, they have not brought satisfactory improvement in the quality of life and treatment of patients. Traditional Chinese herbal medicines and their extracts combine thousands of years of experience and the scientific basis provided by modern experimental research, which is expected to bring a qualitative leap in the clinical management of diabetes. Therefore, this article systematically reviews studies on the effects of Chinese herbal medicine and its extracts on diabetes and its complications, and aims to bring new ideas and options for the clinical treatment of diabetes.

Animal models of cathartic colon

The incidence of cathartic colon has been increasing, but satisfactory treatments are still lacking. In order to study the pathological mechanisms of the disorder and identify effective treatment methods, researchers have established different animal models of cathartic colon. This minireview briefly summarizes several common cathartic colon animal models, induced with anthraquinone laxatives such as rhubarb, total anthraquinone, rhein, and emodin, or induced with diphenylmethane laxatives such as phenolphthalein. The advantages and limitations of these models are evaluated and analyzed. We hope that this review will facilitate the selection of suitable models and improve relevant modeling methods. We anticipate the development of more convenient and stable models that can reflect the characteristics of cathartic colon in humans, and serve as useful tools for further studies.

Editorial for the “Green Chemistry” Section in the Journal Molecules: Focus on Solvents

It is a pleasure to write this editorial highlighting some of the recent papers discussing solvents in the Green Chemistry section of Molecules [...]

Dispersion-free extraction of In(III) from HCl solutions using a supported liquid membrane containing the HA324H+Cl- ionic liquid as the carrier

By reaction of HCl and the tertiary amine HA324, an ionic liquid denoted HA324H⁺Cl⁻ was generated and used in the transport of indium(III) from HCl solutions. Metal transport experiments were carried out with a supported liquid membrane, and several variables affecting the permeation of indium(III) across the membrane were tested: stirring speed, metal and acid concentrations in the feed solutions and the carrier concentration in the supported organic solution. The metal transport results were also compared with those obtained using different carriers in the solid support. A model that described indium(III) transport across the membrane was proposed, and the corresponding diffusional parameters were estimated.

Sustainable Micro-Scale Extraction of Bioactive Phenolic Compounds from Vitis vinifera Leaves with Ionic Liquid-Based Surfactants

This paper proposes a new sustainable and simple strategy for the micro-scale extraction of phenolic compounds from grapevine leaves with analytical purpose. The method is based on a microwave-assisted solid-liquid extraction approach (MA-SLE), using an aqueous solution of an ionic liquid (IL)-based surfactant as extraction phase. The method does not require organic solvents, nor any clean-up step, apart from filtration prior to the injection in the analytical system. Two IL-based surfactants were evaluated, and the method was optimized by using experimental designs, resulting in the use of small amounts of sample (100 mg) and extraction phase (2.25 mL), low concentrations of the selected 1-hexadecyl-3-butyl imidazolium bromide IL (0.1 mM), and 30 min of extraction time. The proposed methodology was applied for the determination of the polyphenolic pattern of six different varieties of Vitis vinifera leaves from the Canary Islands, using high-performance liquid chromatography and photodiode array detection for the quantification of the compounds. The proposed MA-SLE approach was greener, simpler, and more effective than other methods, while the results from the analysis of the leaves samples demonstrate that these by-products can be exploited as a source of natural compounds for many applications.

Facile synthesis and immobilization of boroxine polymers containing carbon chains and their application as adsorbents

Novel boroxine-linked covalent organic polymers was synthesized and immobilized by one pot reaction for extraction of anthraquinones.