Structural characterization and cardioprotective activity of a novel polysaccharide from Fructus aurantii

Regulation of optimized new Shengmai powder on cardiomyocyte apoptosis and ferroptosis in ischemic heart failure rats: The mediating role of phosphatidylinositol-3-kinase/protein kinase B/tumor protein 53 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Optimized New Shengmai Powder (ONSMP) is a sophisticated traditional Chinese medicinal formula renowned for bolstering vital energy, optimizing blood circulation, and mitigating fluid retention. After years of clinical application, ONSMP has shown a significant impact in improving myocardial injury and cardiac function and has a positive effect on treating heart failure. However, many unknowns exist about the molecular biological mechanisms of how ONSMP exerts its therapeutic effects, which require further research and exploration.

AIM OF THE STUDY

Exploring the potential molecular biological mechanisms by which ONSMP ameliorates cardiomyocyte apoptosis and ferroptosis in ischemic heart failure (IHF).

MATERIALS AND METHODS

First, we constructed a rat model of IHF by inducing acute myocardial infarction through surgery and using echocardiography, organ coefficients, markers of heart failure, antioxidant markers, and histopathological examination to assess the effects of ONSMP on cardiomyocyte apoptosis and ferroptosis in IHF rats. Next, we used bioinformatics analysis techniques to analyze the active components, signaling pathways, and core targets of ONSMP and calculated the interactions between core targets and corresponding elements. Finally, we detected the positive expression of apoptosis and ferroptosis markers and core indicators of signaling pathways by immunohistochemistry; detected the mean fluorescence intensity of core indicators of signaling pathways by immunofluorescence; detected the protein expression of signaling pathways and downstream effector molecules by western blotting; and detected the mRNA levels of p53 and downstream effector molecules by quantitative polymerase chain reaction.

RESULTS

ONSMP can activate the Ser83 site of ASK by promoting the phosphorylation of the PI3K/AKT axis, thereby inhibiting the MKK3/6-p38 axis and the MKK4/7-JNK axis signaling to reduce p53 expression, and can also directly target and inhibit the activity of p53, ultimately inhibiting p53-mediated mRNA and protein increases in PUMA, SAT1, PIG3, and TFR1, as well as mRNA and protein decreases in SLC7A11, thereby inhibiting cardiomyocyte apoptosis and ferroptosis, effectively improving cardiac function and ventricular remodeling in IHF rat models.

CONCLUSION

ONSMP can inhibit cardiomyocyte apoptosis and ferroptosis through the PI3K/AKT/p53 signaling pathway, delaying the development of IHF.

Menthol induces apoptosis and inhibits proliferation and migration of nonsmall cell lung carcinoma in vitro and in vivo through Akt pathway

BACKGROUND

About 40% of nonsmall cell lung cancers (NSCLCs) have already progressed in an advanced stage at the time of diagnosis. Development of effective prevention and therapy approaches against NSCLC is critical for reducing mortality. As a fundamental ingredient of peppermint oil, menthol has been demonstrated to possess an antitumor activity in several types of carcinomas. However, the potential role of menthol on NSCLC has not been reported. The present study aims to investigate the effect and underlying mechanism of menthol on proliferation, apoptosis, and mobility of human lung adenocarcinoma.

METHODS

Cell apoptosis was examined by MTT and flow cytometry. The motility of cells was determined by Transwell assay. Western blot analysis was performed to determine expression level of proteins. In vivo model of nude mice was established for evaluating the influence of menthol on tumorigenicity of A549 cells. The expression lentiviral vector of Akt was established in NSCLC cells for further verifying the inhibiting effect of menthol on survival and mobility of NSCLC cells via Akt pathway.

RESULTS

The results showed that menthol promoted A549 cell apoptosis, suppressed cell proliferation, and motility by altering the phosphorylated protein level of Akt. Menthol enhanced the expression level of Bax while decreasing expression of Bcl-2, Caspase-3, and MMPs proteins. In vivo experiments suggested that menthol exhibited an inhibitory effect in tumor growth on xenografts. These results were further validated in Akt over-expressed A549 and H1299 cells.

CONCLUSIONS

Menthol could display an inhibitory effect on NSCLC cells through Akt signaling pathway, making it a potential target for NSCLC treatment.

Comparison of structures and emulsifying properties between water-extracted pectins from Fructus aurantii

The structural characteristics of two water-extracted pectic polysaccharides from Fructus aurantii were investigated, and the impacts of their structures on the emulsifying stability were evaluated. FWP-60 (extracted by cold water and followed 60 % ethanol precipitation) and FHWP-50 (extracted by hot water and followed 50 % ethanol precipitation) were both high methyl-esterified pectins, which were composed of homogalacturonan (HG) and highly branched rhamnogalacturonan I (RG-I) regions. The weight-average molecular weight, methyl-esterification degree (DM) and HG/RG-I ratio of FWP-60 were 1200 kDa, 66.39 % and 4.45, respectively, which were 781 kDa, 79.10 % and 1.95 for FHWP-50. The methylation and NMR analysis of FWP-60 and FHWP-50 demonstrated that the main backbone consisted of different molar ratios of →4)-α-GalpA-(1 → and →4)-α-GalpA-6-O-methyl-(1→, and the side chains contained arabinan and galactan. Moreover, the emulsifying properties of FWP-60 and FHWP-50 were discussed. Compared with FHWP-50, FWP-60 had better emulsion stability. Overall, pectin had a linear HG domain and a small number of RG-I domain with short side chains to facilitate the stabilization of emulsions in Fructus aurantii. A comprehensive knowledge of the structure characteristic and emulsifying property would enable us to provide more information and theoretical guidance for the structure and emulsion preparation of Fructus aurantii pectic polysaccharides.

Structural characterization and anti-inflammatory effects of an arabinan isolated from Rehmannia glutinosa Libosch

Considering that natural polysaccharides are potential anti-inflammatory agents, in this study, an arabinan (RGP70-2) was isolated and purified from Rehmannia glutinosa Libosch. (R. glutinosa) and its structure was characterized. RGP70-2 was a homogeneous polysaccharide with a molecular weight of 6.7 kDa, with the main backbone comprising →5)-α-L-Araf-(1→, →3)-α-L-Araf-(1→, →2,3,5)-α-L-Araf-(1→, and →2,5)-α-L-Araf-(1 → linkages and the side chain comprising an α-L-Araf-(1 → linkage. In vivo experiments showed that RGP70-2 inhibited ROS production and downregulated the expression of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6). In vitro experiments showed that RGP70-2 decreased levels of pro-inflammatory cytokines, inhibited ROS production, and attenuated NF-κB-p65 translocation from the cytoplasm to the nucleus. Our results showed that RGP70-2 may delay inflammation by regulating the ROS-NF-κB pathway. Thus, RGP70-2 has potential applications as an anti-inflammatory agent in the biopharmaceutical industry.

Advances in health-promoting effects of natural polysaccharides: Regulation on Nrf2 antioxidant pathway

Natural polysaccharides (NPs) possess numerous health-promoting effects, such as liver protection, kidney protection, lung protection, neuroprotection, cardioprotection, gastrointestinal protection, anti-oxidation, anti-diabetic, and anti-aging. Nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidant pathway is an important endogenous antioxidant pathway, which plays crucial roles in maintaining human health as its protection against oxidative stress. Accumulating evidence suggested that Nrf2 antioxidant pathway might be one of key regulatory targets for the health-promoting effects of NPs. However, the information concerning regulation of NPs on Nrf2 antioxidant pathway is scattered, and NPs show different regulatory behaviors in their different health-promoting processes. Therefore, in this article, structural features of NPs having regulation on Nrf2 antioxidant pathway are overviewed. Moreover, regulatory effects of NPs on this pathway for health-promoting effects are summarized. Furthermore, structure-activity relationship of NPs for health-promoting effects by regulating the pathway is preliminarily discussed. Otherwise, the prospects on future work for regulation of NPs on this pathway are proposed. This review is beneficial to well-understanding of underlying mechanisms for health-promoting effects of NPs from the view angle of Nrf2 antioxidant pathway, and provides a theoretical basis for the development and utilization of NPs in promoting human health.

Cardiovascular Protective Effects of Plant Polysaccharides: A Review

Cardiovascular disease is a kind of heart, brain, and blood vessel injury disease by the interaction of various pathological factors. The pathogenesis of cardiovascular disease is complex with various risk factors, including abnormally elevated blood pressure, glucose, and lipid metabolism disorders, atherosclerosis, thrombosis, etc. Plant polysaccharides are a special class of natural products derived from plant resources, which have the characteristics of wide sources, diverse biological activities, and low toxicity or side effects. Many studies have shown that plant polysaccharides improve cardiovascular diseases through various mechanisms such as anti-oxidative stress, restoring the metabolism of biological macromolecules, regulating the apoptosis cascade to reduce cell apoptosis, and inhibiting inflammatory signal pathways to alleviate inflammation. This article reviews the pharmacological effects and protective mechanisms of some plant polysaccharides in modulating the cardiovascular system, which is beneficial for developing more effective drugs with low side effects for management of cardiovascular diseases.

The anti-hyperuricemic effects of green alga Enteromorpha prolifera polysaccharide via regulation of the uric acid transporters in vivo

A novel polysaccharide obtained from Enteromorpha prolifera (EPP) was purified through diethylaminoethyl cellulose-52 and Sephadex G-75 chromatography. Fourier transform infrared spectroscopy, high-performance liquid chromatography, and nuclear magnetic resonance (NMR) spectroscopy were employed to analyse the structure of EPP. It mainly comprised rhamnose, glucuronic acid, galactose, arabinose, and xylose at a molar ratio of 20.45:12.74:10.99:5.84:1.95, and its average molecular weight was 46.56 kDa. The seven major glycosidic residues identified by NMR were as follows: →2)-α-L-Araf-(1→, →2)-α-L-Rhap-(1→, →4)-α-L-Rhap-(1→, →2,6)-β-D-Galp-(1→, →4)-β-D-GlcpA-(1→, →3,4)-β-D-GlcpA-(1→, and →4)-β-Xylp-(1→. The effect of EPP on hyperuricemic mice was determined by analysing correlative general physical parameters, renal histopathology, renal gene expressions, and gut microbiome. EPP significantly reduced serum uric acid (UA), serum blood urea nitrogen, serum xanthine oxidase (XOD), and hepatic XOD as well as improved histological parameters in hyperuricemic mice. Furthermore, mRNA and protein expression analyses showed the upregulation of UA excretion genes such as ABCG2, OAT1, and NPT1 and downregulation of UA resorption gene URAT1. Moreover, EPP maintained the stability of the intestinal flora and confirmed that Parasutterella is closely related to the regulation of hyperuricemia. This study is the first to demonstrate the anti-hyperuricemic activity of EPP and highlight its therapeutic potential for hyperuricemia-related diseases.

Anti-hypertensive and cardioprotective activities of traditional Chinese medicine-derived polysaccharides: A review

Cardiovascular diseases (CVDs), a leading cause of death in modern society, have become a major public health issue globally. Although numerous approaches have been proposed to reduce morbidity and mortality, the pursuit of pharmaceuticals with more preventive and/or therapeutic value remains a focus of attention. Being a vast treasure trove of natural drug molecules, Traditional Chinese Medicine (TCM) has a long history of clinical use in the prophylaxis and remedy of CVDs. Increasing lines of preclinical evidence have demonstrated the effectiveness of TCM-derived polysaccharides on hindering the progression of CVDs, e.g. hypertension, myocardial infarction. However, to the best of our knowledge, there are few reviews on the application of TCM-derived polysaccharides in combating CVDs. Hence, we provide an overview of primary literature on the anti-hypertensive and cardioprotective activities of herbal polysaccharides. Additionally, we also discuss the current limitations and propose a new hypothesis about how polysaccharides exert cardiovascular effects based on the metabolism of polysaccharides.

The important role of polysaccharides from a traditional Chinese medicine-Lung Cleansing and Detoxifying Decoction against the COVID-19 pandemic

The new coronavirus pneumonia, named COVID-19 by the World Health Organization, has become a pandemic. It is highly pathogenic and reproduces quickly. There are currently no specific drugs to prevent the reproduction and spread of COVID-19. Some traditional Chinese medicines, especially the Lung Cleansing and Detoxifying Decoction (Qing Fei Pai Du Tang), have shown therapeutic effects on mild and ordinary COVID-19 patients. Polysaccharides are important ingredients in this decoction. This review summarizes the potential pharmacological activities of polysaccharides isolated by hot water extraction from Lung Cleansing and Detoxifying Decoction, which is consistent with its production method, to provide the theoretical basis for ongoing research on its application.