Cardioprotective effect of Aralia elata polysaccharide on myocardial ischemic reperfusion (IR) injury in rats

A mini-review of isolation, purification, structural characteristics and bioactivities of polysaccharides from Aralia elata (Miq.) Seem

In recent years, the isolation, purification, structural characterization of plant polysaccharides from natural resources have arrested widespread attention. Aralia elata (Miq.) Seem (A. elata) belongs to the Aralia genus of the Araliaceae family, which is one of the most popular edible mountain vegetables in East Asia. A. elata has been widely distributed in China, particularly in Liaoning, Jilin, and Heilongjiang provinces in northeast China, in which it has been used as a traditional herbal medicine for thousands of years to treat various diseases, such as hepatitis and rheumatoid arthritis. A. elata polysaccharides (AEPs) are one of the major active ingredients of A. elata, the monosaccharide composition of which consist primarily of Gal, Glc, Man, Ara, and Rha, with molecular weights ranging from 1.56 × 104 Da to 1.12 × 105 Da. AEPs have attracted worldwide attention owing to their various biological activities, including antioxidant activity, antitumor activity and hepatoprotection. The present review aims to comprehensively summarize the research advances on the polysaccharides isolated from A. elata, including the extraction, separation, physical-chemical properties, structural characteristics, and bioactivities over the past few decades. This review would establish a solid foundation for further development and application in the field of AEPs.

Structural and in vivo-in vitro myocardial injury protection features of two novel polysaccharides from Allium macrostemon Bunge and Allium chinense G. Don

This study aimed to investigate the structural characteristics, in vivo antiatherosclerosis activity, and in vitro myocardial injury protection effects of polysaccharides from Allium macrostemon Bunge and Allium chinense G. Don. Thus, crude polysaccharides of Allium macrostemon Bunge and Allium chinense G. Don significantly reduced serum lipid levels, improved cardiac myocyte morphology and arrangement, and relieved the development of myocardial fibrosis. Meanwhile, the lesion areas of the aorta and aortic valve had evident visual improvements. Furthermore, two main novel purified polysaccharides, namely, AMB-1 and ACGD-1, were isolated and characterized from crude Allium macrostemon Bunge and Allium chinense G. Don fractions, respectively. The purified polysaccharides mainly consisted of fructose and glucose and had molecular weights of 25.22 and 19.53 kDa, respectively. In addition, Fourier transform infrared spectroscopy, methylation, and nuclear magnetic resonance data revealed the primary structures of the AMB1 (or ACGD1) backbone with branched side chains. Scanning electron microscope analysis showed that the purified polysaccharides were both piled together in a lamellar or clastic form with a smooth surface along with linear or irregular bulges. Moreover, the purified polysaccharides both showed nontoxicity on H9c2 cells and effectively dropped hypoxia/reoxygenation-induced apoptosis by the BCL-2/BAX pathway. Overall, the characterization of the structural properties and in vivo and in vitro myocardial injury protection effects of Allium macrostemon Bunge and Allium chinense G. Don polysaccharides enriched our understanding of their nutritional and medicinal values. To the best of our knowledge, this is the first study on the structural characteristics and bioactivities of Allium chinense G. Don polysaccharides.

Medicinal Plants in the Treatment of Myocardial Infarction Disease: A Systematic Review

BACKGROUND

Myocardial infarction (MI), also referred to as a "heart attack," is brought on by a partial or total interruption of blood supply to the myocardium. Myocardial infarction can be "silent," go undiagnosed, or it can be a catastrophic occurrence that results in hemodynamic decline and untimely death. In recent years, herbal remedies for MI have become effective, secure, and readily accessible.

OBJECTIVE

The purpose of this review was to examine the medicinal plants and phytochemicals that have been used to treat MI in order to assess the potential contribution of natural substances to the development of herbal MI treatments.

METHODOLOGY

A literature search was employed to find information utilizing electronic databases, such as Web of Science, Google Scholar, PubMed, Sci Finder, Reaxys, and Cochrane.

RESULTS

The identification of 140 plants from 12 families led to the abstraction of data on the plant families, parts of the plant employed, chemical contents, extracts, model used, and dose.

CONCLUSION

The majority of the MI plants, according to the data, belonged to the Fabaceae (11%) and Asteraceae (9%) families, and the most prevalent natural components in plants with MI were flavonoids (43%), glucosides (25%), alkaloids (23%), phenolic acid (19%), saponins (15%), and tannins (12%).

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 Potential of Introduction of Asian Vegetables in Europe

Increasing longevity, along with an aging population in Europe, has caused serious concerns about diet-related chronic diseases such as obesity, diabetes, cardiovascular diseases, and certain cancers. As recently noted during the coronavirus pandemic, regular exercise and a robust immune system complemented by adequate consumption of fruit and vegetables are recommended due to their known health benefits. Although the volume of fresh vegetable consumption in the EU is barely growing, demand for diversified, nutritious, and exotic vegetables has been increasing. Therefore, the European market for fresh Asian vegetables is expected to expand across the EU member states, and the introduction of new vegetables has enormous potential. We conducted this review to address the high number and wide range of Asian vegetable species with a commercial potential for introduction into the current European vegetable market. Many of them have not received any attention yet. Four Asian vegetables: (1) Korean ginseng sprout, (2) Korean cabbage, (3) Coastal hog fennel and (4) Japanese (Chinese or Korean) angelica tree, are further discussed. All of these vegetables possess several health benefits, are increasingly in demand, are easy to cultivate, and align with current trends of the European vegetable market, e.g., vegetables having a unique taste, higher value, are decorative and small. Introducing Asian vegetables will enhance the diversity of nutritious horticultural products in Europe, associated with all their respective consumption benefits. Future research on the Asian vegetable market within Europe is needed. In addition, experimental studies of Asian vegetables under practical conditions for their production in different European environments are required. Economic, social, and ecological aspects also ought to be considered.

Ganoderic acid A alleviates myocardial ischemia-reperfusion injury in rats by regulating JAK2/STAT3/NF-κB pathway

This study aimed to investigate the protective effect of GanodericacidA (GA) on myocardial ischemia-reperfusion (MIR) injury. The myocardial injury model in rats was established by ligating left anterior descending coronary artery. We measured cardiac hemodynamic, antioxidant enzyme activity, and various biochemical indexes of myocardial tissue, and evaluated myocardial infarction and damage. Further, the expression of JAK2/STAT3/NF-κB signaling pathway-related proteins in myocardial tissue was measured by western blot. The results showed that the myocardial infarction extention was obviously reduced upon GA treatment. Compared with the control group, ischemia-reperfusion rats showed significant increase in lactate dehydrogenase (LDH) and creatine Kinase (CK), which were significantly decreased in GA group. Besides, GA pretreatment effectively decreased the levels of inflammatory cytokines in serum. The phosphorylation of Janus Kinase 2 (JAK2), signal transducer and activator of transcription (STAT3)and Nuclear factor-κB (NF-κB) in reperfusion group were significantly higher than that in control group, which were reversed upon GA treatment. In conclusion, GA may reduce myocardial injury by regulating JAK2/STAT3/NF-κB pathway.

Araloside C attenuates atherosclerosis by modulating macrophage polarization via Sirt1-mediated autophagy

Atherosclerosis-related cardiovascular disease is still the predominant cause of death worldwide. Araloside C (AsC), a natural saponin, exerts extensive anti-inflammatory properties. In this study, we explored the protective effects and mechanism of AsC on macrophage polarization in atherosclerosis in vivo and in vitro. Using a high-fat diet (HFD)-fed ApoE-/- mouse model and RAW264.7 macrophages exposed to ox-LDL, AsC was evaluated for its effects on polarization and autophagy. AsC significantly reduced the plaque area in atherosclerotic mice and lipid accumulation in ox-LDL-treated macrophages, promoted M2 phenotype macrophage polarization, increased the number of autophagosomes and modulated the expression of autophagy-related proteins. Moreover, the autophagy inhibitor 3-methyladenine and BECN1 siRNA obviously abolished the antiatherosclerotic and M2 macrophage polarization effects of AsC. Mechanistically, AsC targeted Sirt1and increased its expression, and this increase in expression was associated with increased autophagy and M2 phenotype polarization. In contrast, the effects of AsC were markedly blocked by EX527 and Sirt1 siRNA. Altogether, AsC attenuates foam cell formation and lessens atherosclerosis by modulating macrophage polarization via Sirt1-mediated autophagy.

Structural characteristics and hepatoprotective potential of Aralia elata root bark polysaccharides and their effects on SCFAs produced by intestinal flora metabolism

The structural characteristics of the polysaccharides from Aralia elata root barks (AERP) were systematically investigated by FT-IR, HPSEC-ELSD and colorimetric methods as well as by GCMS based monosaccharide compositions, Smith degradations, and methylation analysis. The result showed average molecular weights of AERP were between 42.7 kDa and 93.9 kDa. AERP was composed of Ara, Rha, GlcA, Man, Glc, and Gal in a molar ratio of 22.2: 10.3: 8.1: 32.7: 5.7: 21.2 along with a small number of sulfate (3.38%) and acetyl (4.87%) groups. The abundant glycosidic linkages of Man, Ara, Gal, and Rha were observed as more than 90% of all the monosaccharides detected. Studies to evaluate hepatoprotective potentials of AERP showed that they had potent hepatoprotective effects in vivo in carbon tetrachloride-induced acute liver injury (CIALI) in mice by histopathological evaluation, biochemical examinations and ELISA assays. GCMS was further used to determine the effects of AERP on the chemical profiles of nine common short-chain fatty acids (SCFAs) produced by intestinal flora metabolism in CIALI mice. These findings not only provide novel insights into the pharmacological actions of AERP on the protection from CIALI in mice, but they also demonstrate that determining SCFA profiles by targeted GC-MS metabolomics is an effective technique to investigate the molecular mechanisms of the effects of plant polysaccharides on intestinal flora metabolism.

Cardioprotective Effect of Aloe vera Biomacromolecules Conjugated with Selenium Trace Element on Myocardial Ischemia-Reperfusion Injury in Rats

The present study was undertaken to evaluate the cardioprotection potential and underlying molecular mechanism afforded by a selenium (Se) polysaccharide (Se-AVP) from Aloe vera in the ischemia-reperfusion (I/R) model of rats in vivo. Myocardial I/R injury was induced by occluding the left anterior descending coronary artery (LAD) for 30 min followed by 2-h continuous reperfusion. Pretreatment with Se-AVP (100, 200, and 400 mg/kg) attenuated myocardial damage, as evidenced by reduction of the infarct sizes, increase in serum and myocardial endogenous antioxidants (superoxide dismutase (SOD), glutathione peroxidase (GSH), and catalase (CAT)), and decrease in the malondialdehyde (MDA) level in the rats suffering I/R injury. This cardioprotective activity afforded by Se-AVP is further supported by the decreased levels of cardiac marker enzymes creatine kinase (CK) and lactate dehydrogenase (LDH), as well as the rise of myocardial Na⁺-K⁺-ATPase and Ca²⁺-Mg²⁺-ATPase activities in I/R rats. Additionally, cardiomyocytic apoptosis was measured by terminal-deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) staining and the result showed that the percent of TUNEL-positive cells in myocardium of Se-AVP-treated groups was lower than I/R rats. In conclusion, we clearly demonstrated that Se-AVP had a protective effect against myocardial I/R injury in rats by augmenting endogenous antioxidants and protecting rat hearts from oxidative stress-induced myocardial apoptosis.

Phellinus linteus Mycelium Alleviates Myocardial Ischemia-Reperfusion Injury through Autophagic Regulation

The incidence of myocardial ischemia-reperfusion (IR) injury is rapidly increasing around the world and this disease is a major contributor to global morbidity and mortality. It is known that regulation of programmed cell death including apoptosis and autophagy reduces the impact of myocardial IR injury. In this study, the cardioprotective effects and underlying mechanisms of Phellinus linteus (Berk. and Curt.) Teng, Hymenochaetaceae (PL), a type of medicinal mushroom, were examined in rats subjected to myocardial IR injury. The left main coronary artery of rats was ligated for 1 h and reperfused for 3 h. The arrhythmia levels were monitored during the entire process and the infarct size was evaluated after myocardial IR injury. Furthermore, the expression levels of proteins in apoptotic and autophagic pathways were observed. Pretreatment with PL mycelium (PLM) significantly reduced ventricular arrhythmia and mortality due to myocardial IR injury. PLM also significantly decreased myocardial infarct size and plasma lactate dehydrogenase level after myocardial IR injury. Moreover, PLM administration resulted in decreased caspase 3 and caspase 9 activation and increased Bcl-2/Bax ratio. Phosphorylation level of AMPK was elevated while mTOR level was reduced. Becline-1 and p62 levels decreased. These findings suggest that PLM is effective in protecting the myocardium against IR injury. The mechanism involves mediation through suppressed pro-apoptotic signaling and regulation of autophagic signaling, including stimulation of AMPK-dependent pathway and inhibition of beclin-1-dependent pathway, resulting in enhancement of protective autophagy and inhibition of excessive autophagy.

Synthesis and biological evaluation of the codrug of Leonurine and Aspirin as cardioprotective agents

The novel codrugs of Leonurine and Aspirin, compounds 545 and 503 have been synthesized and evaluated on their cardioprotective effects. Preliminary pharmacological studies showed that both compounds 545 and 503 were able to increase cell viability of hypoxia-induced H9c2 cells, and compound 545 exhibited at least ten fold potency than 503 and their parent drugs (Leonurine and Aspirin). Further mechanisms studies indicated that the cardioprotective effect of 545 due to its (1) anti-oxidative ability by increasing SOD and CAT enzymes activity and decreasing MDA content and LDH leakage rate, (2) anti-apoptosis activity by regulating apoptosis-associated proteins expression during hypoxia, (3) anti-inflammatory effect by suppression of pro-inflammatory mediators. All of these results demonstrate that compound 545 as a new class of Leonurine analogue could be a drug candidate in our further drug development studies.

Total saponins from Aralia taibaiensis protect against myocardial ischemia/reperfusion injury through AMPK pathway

It was previously shown that total saponins extracted from Aralia taibaiensis (sAT) have potent antioxidant activities for treating diabetes mellitus and attenuate D-galactose-induced aging. Since diabetes mellitus and aging are closely associated with cardiac dysfunction, particularly ischemic heart disease, sAT may have potential protective activity against myocardial ischemia/reperfusion injury (MI/RI). However, the anti-MI/RI effects of sAT have yet to be examined, and the possible molecular mechanisms remain to be determined. The present study was undertaken to investigate the anti-MI/RI activities of sAT and to elucidate the mechanisms underlying these effects in rats using TUNEL and Hoechst 33258 staining. The results confirmed the cardioprotective effects in vivo and elucidated the potential molecular mechanisms of sAT in vitro. Pretreatment with sAT significantly reduced infarct size, decreased the levels of lactate dehydrogenase and creatine kinase in the serum and blocked apoptosis. In addition, sAT inhibited A/R-induced apoptosis by decreasing DNA strand breaks, caspase-3 activity and cytochrome c release in H9c2 cells. Furthermore, sAT markedly increased the phosphorylation of AMP-activated protein kinase (AMPK) and acetyl CoA carboxylase and elevated the Bcl2/Bcl-2-associated X protein ratio. These effects were blocked by compound C. The results suggested that sAT pretreatment exerts protective effects on myocardial cells in vitro and in vivo against MI/RI-induced apoptosis by activating AMPK pathway.