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.

Screening of Suitable Reference Genes for Immune Gene Expression Analysis Stimulated by Vibrio anguillarum and Copper Ions in Chinese Mitten Crab (Eriocheir sinensis).

The reference gene expression is not always stable under different experimental conditions, and screening of suitable reference genes is a prerequisite in quantitative real-time polymerase chain reaction (qRT-PCR). In this study, we investigated gene selection, and the most stable reference gene for the Chinese mitten crab (Eriocheir sinensis) was screened under the stimulation of Vibrio anguillarum and copper ions, respectively. Ten candidate reference genes were selected, including arginine kinase (AK), ubiquitin-conjugating enzyme E2b (UBE), glutathione S-transferase (GST), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), elongation factor 1α (EF-1α), α-tubulin (α-TUB), heat shock protein 90 (HSP90), ß-actin (ß-ACTIN), elongation factor 2 (EF-2) and phosphoglucomutase 2 (PGM2). Expression levels of these reference genes were detected under the stimulation of V. anguillarum at different times (0 h, 6 h, 12 h, 24 h, 48 h and 72 h) and copper ions in different concentrations (11.08 mg/L, 2.77 mg/L, 0.69 mg/L and 0.17 mg/L). Four types of analytical software, namely geNorm, BestKeeper, NormFinder and Ref-Finder, were applied to evaluate the reference gene stability. The results showed that the stability of the 10 candidate reference genes was in the following order: AK > EF-1α > α-TUB > GAPDH > UBE > ß-ACTIN > EF-2 > PGM2 > GST > HSP90 under V. anguillarum stimulation. It was GAPDH > ß-ACTIN > α-TUB > PGM2 > EF-1α > EF-2 > AK > GST > UBE > HSP90 under copper ion stimulation. The expression of E. sinensis Peroxiredoxin4 (EsPrx4) was detected when the most stable and least stable internal reference genes were selected, respectively. The results showed that reference genes with different stability had great influence on the accurate results of the target gene expression. In the Chinese mitten crab (E. sinensis), AK and EF-1α were the most suitable reference genes under the stimulation of V. anguillarum. Under the stimulation of copper ions, GAPDH and ß-ACTIN were the most suitable reference genes. This study provided important information for further research on immune genes in V. anguillarum or copper ion stimulation.

Alteration of antioxidant status, glucose metabolism, and hypoxia signal pathway in Eirocheir sinensis after acute hypoxic stress and reoxygenation.

Dissolved oxygen (DO) is crucial for the survival of Chinese mitten crab (Eirocheir sinensis); low DO levels adversely affect the health of these crabs. In this study, we evaluated the underlying response mechanism of E. sinensis to acute hypoxic stress by analyzing antioxidant parameters, glycolytic indicators, and hypoxia signaling factors. The crabs were exposed to hypoxia for 0, 3, 6, 12, and 24 h and reoxygenated for 1, 3, 6, 12, and 24 h. The hepatopancreas, muscle, gill, and hemolymph were sampled at different exposure times to detect the biochemical parameters and gene expression. The results showed that the activity of catalase, antioxidants, and malondialdehyde in tissues significantly increased under acute hypoxia and gradually decreased during the reoxygenation phase. Under acute hypoxic stress, glycolysis indices, including hexokinase (HK), phosphofructokinase, pyruvate kinase (PK), pyruvic acid (PA), lactate dehydrogenase (LDH), lactic acid (LA), succinate dehydrogenase (SDH), glucose, and glycogen in the hepatopancreas, hemolymph, and gills increased to varying degrees but recovered to the control levels after reoxygenation. Gene expression data showed that hypoxia signaling pathway-related genes, including hypoxia-inducible factor-1α/ß (HIF1α/ß), prolyl hydroxylase (PHD), factor inhibiting hypoxia-inducible factor (FIH), and glycolysis-related factors (HK and PK) were upregulated, showing that the HIF signaling pathway was activated under hypoxic conditions. In conclusion, acute hypoxic exposure activated the antioxidant defense system, glycolysis, and HIF pathway to respond to adverse conditions. These data contribute to elucidating the defense and adaptive mechanisms of crustaceans to acute hypoxic stress and reoxygenation.

High Value-Added Application of Two Renewable Sources as Healthy Food: The Nutritional Properties, Chemical Compositions, Antioxidant, and Antiinflammatory Activities of the Stalks of Rheum officinale Baill. and Rheum tanguticum Maxim. ex Regel.

Rhubarb plants (Rheum officinale and R. tanguticum) have edible stalks. In this work, we aimed to compare the nutritional properties, chemical compositions, and bioactivities of R. officinale (SRO) and R. tanguticum (SRT) stalks and to analyze the composition-function relationship. Results showed that the two stalks were good sources of fiber, as well as minerals. They contained abundant essential amino acids and essential fatty acids to regulate the immunity and prevent some chronic diseases; the contents of polyunsaturated fatty acids were 2,244.32 mg/100 g and 2,844.69 mg/100 g, respectively. The antioxidant activity were also proved. Metabolomics showed that SRO and SRT contained abundant phenolic acids. Due to the higher concentrations of flavones, SRT has better antiinflammatory activities than SRO by inhibiting NF-κB signaling pathway. Rhubarb stalks exhibited good safety in acute toxicity and cytotoxicity tests. This work indicated that the two stalks have nutritional value, safety, and bioactivities, and could be used as sources of nutritional ingredients for regulating the immunity of body in food industry.

Accelerated degradation of polyetheretherketone and its composites in the deep sea.

The performance of polymer composites in seawater, under high hydrostatic pressure (typically few tens of MPa), for simulating exposures at great depths in seas and oceans, has been little studied. In this paper, polyetheretherketone (PEEK) and its composites reinforced by carbon fibres and glass fibres were prepared. The seawater environment with different seawater hydrostatic pressure ranging from normal pressure to 40 MPa was simulated with special equipment, in which the seawater absorption and wear behaviour of PEEK and PEEK-based composites were examined in situ. The effects of seawater hydrostatic pressure on the mechanical properties, wear resistance and microstructure of PEEK and its composites were focused on. The results showed that seawater absorption of PEEK and its composites were greatly accelerated by increased hydrostatic pressure in the deep sea. Affected by seawater absorption, both for neat PEEK and composites, the degradation on mechanical properties, wear resistance and crystallinity were induced, the degree of which was increasingly serious with the increase of hydrostatic pressure of seawater environment. There existed a good correlation in an identical form of exponential function between the wear rate and the seawater hydrostatic pressure. Moreover, the corresponding mechanisms of the effects of deep-sea hydrostatic pressure were also discussed.