Protective Effects of Caesalpinia sappan Linn. and Its Bioactive Compounds on Cardiovascular Organs

Uncovering the naturally occurring covalent inhibitors of SARS-CoV-2 Mpro from the Chinese medicine sappanwood and deciphering their synergistic anti-Mpro effects

ETHNOPHARMACOLOGICAL RELEVANCE

The Chinese medicine sappanwood is primarily sourced from the dried heartwood of the medicinal plant Caesalpinia sappan Linn., which has been found with a variety of valuable properties including anti-inflammatory, anti-oxidant, and anti-viral effects. Preliminary investigations have demonstrated that sappanwood showed strong anti-SARS-CoV-2 Mpro effects, but the key constituents responsible for SARS-CoV-2 Mpro inhibition and their anti-Mpro mechanisms have not been uncovered.

AIM OF THE STUDY

This study aims to uncover the naturally occurring covalent inhibitors of SARS-CoV-2 Mpro from the sappanwood extract (SWE), to characterize the anti-Mpro mechanisms of the newly identified inhibitors in SWE, as well as to elucidate their synergistic anti-Mpro mechanisms.

MATERIALS AND METHODS

The proteolytic activity of SARS-CoV-2 Mpro was monitored using a fluorescence-based biochemical assay. Comprehensive phytochemical profiling of SWE was conducted by UHPLC-Q-Exactive Orbitrap HRMS. The nanoLC-MS/MS-based chemoproteomic profiling was employed to characterize the phytochemical-modified peptides of SARS-CoV-2 Mpro. Inactivation kinetics, surface plasmon resonance, and molecular dynamics (MD) simulations were utilized to investigate the binding affinity and binding modes of the newly identified SARS-CoV-2 Mpro inhibitors.

RESULTS

SWE was found with strong anti-Mpro effect in both dose- and time-dependent manners. Twenty-three constituents in SWE were subsequently identified by utilizing UHPLC-Q-Exactive Orbitrap HRMS, while chemoproteomic profiling revealed that 14 constituents in SWE could covalently modify SARS-CoV-2 Mpro. The anti-SARS-CoV-2 Mpro effects of these newly identified Mpro binders were then tested one by one. The results showed that most of the tested phytochemicals in SWE exhibited time-dependent inhibition on SARS-CoV-2 Mpro, while hematoxylin, brazilin, sappanchalcone, and protosappanin B were identified as the potent time-dependent inhibitors against SARS-CoV-2 Mpro. Furthermore, the combination of hematoxylin and protosappanin B could synergistically block the formation of catalytic active Mpro dimers and then significantly inhibit the catalytic activity of Mpro. MD simulations provided further insight into the synergistic effects between two identified natural Mpro inhibitors (hematoxylin and protosappanin B).

CONCLUSIONS

The naturally occurring covalent inhibitors of SARS-CoV-2 Mpro from the SWE were identified using an integrated approach. Among all identified covalent inhibitors of SARS-CoV-2 Mpro, hematoxylin, brazilin, sappanchalcone, and protosappanin B emerged as the efficacious Mpro inactivators, which offers powerful evidence to support the anti-coronavirus effects of the Chinese medicine sappanwood.

Caesalpinia sappan L. ethyl acetate extract regulated angiogenesis in atherosclerosis by modulating the miR-126/VEGF signalling pathway

Aims of the study

To investigate the regulatory mechanism of Caesalpinia sappan L. ethyl acetate extract (CSEAE) on angiogenesis in atherosclerosis (AS) based on the miR-126/VEGF signalling pathway.

Materials and methods

Our study first screened for differentially expressed microRNAs (miRNAs) associated with AS using the Gene Expression Omnibus (GEO) public database at the National Center for Biotechnology Information (NCBI) and R language software. Subsequently, our study verified the target-regulatory relationship between miR-126 and vascular endothelial growth factor (VEGF) in human umbilical vein endothelial cells (HUVECs) by using the "TargetScan" website and dual-luciferase reporter assay. In cellular experiments, Our study used cell proliferation assays and flow cytometry to assess the effects of CSEAE-Mediated serum on the proliferation and apoptosis of HUVECs. In animal experiments, our study used HE staining, Oil Red O staining and immunohistochemistry (IHC) staining to detect plaque area/lumen area (%), lipid area/plaque area (%) and microvessel density (MVD) in mouse aortas. In addition, our study performed RT‒PCR, ELISA and Western blot assays in ex vivo and in vivo experiments.

Results

A total of 39 differentially expressed miRNAs of AS were identified, among which the miR-126 expression level was significantly downregulated. Dual luciferase reporter gene assay results showed that miR-126 and VEGF have a targeting relationship, and the miR-126 mimic could inhibit the luciferase activity of the wild-type VEGF reporter gene vector (p value < 0.01). In cellular experiments, cell proliferation assays and flow cytometry results showed that CSEAE-Mediated serum significantly increased the proliferative activity after 24-72 h of treatment (p-value <0.01) and decreased the apoptotic level of HUVECs (p value < 0.01), and RT‒PCR results showed that CSEAE-Mediated serum significantly upregulated the expression of miR-126 (p value < 0.01) and downregulated the expression of VEGF mRNA in HUVECs (p value < 0.01). In vivo experiments, HE staining and IHC staining showed that CSEAE significantly reduced the MVD in the aorta and plaques of mice (p value < 0.01) and significantly reduced the aortic plaque area/lumen area (%) (p value < 0.01). Moreover, RT‒PCR assay and Western blot analysis results showed that CSEAE significantly upregulated the expression of miR-126 (p value < 0.01), downregulated the expression of VEGF mRNA (p value < 0.01), and decreased the protein expression levels of VEGF (p value < 0.01), phosphatidyl-inositol-3-kinase (PI3K) (p value < 0.01), and Ser/Thr-protein kinase (AKT1) (p value < 0.01) in mouse aortas, while ELISA showed that CSEAE significantly reduced the serum levels of vascular endothelial growth factor receptor (VEGFR2) (p value < 0.01) and hypoxia-inducible factor-1 (HIF-1) (p value < 0.01) in mice.

Conclusion

This study emphasises CSEAE as a natural medicinal extract for the treatment of AS that can improve the migratory viability and reduce the apoptosis of HUVECs to maintain the health of the arterial endothelial microenvironment, while CSEAE also inhibits angiogenesis and delays plaque formation in ApoE-/- mice, suggesting that the therapeutic effect of CSEAE for AS may be related to its inhibition of neovascularisation and that its molecular mechanism may be related to the miR-126/VEGF signalling pathway.

Antiplatelet Effects of a Combination of Sappan Wood (Caesalpinia sappan L.) and Red Ginger (Zingiber officinale var. Rubrum) Extracts in a High-Fat Diet-Induced Rat Model

Background: Antithrombotic medications, including antiplatelet agents, are standard treatments for patients with hyperlipidemia who have a high risk of developing cardiovascular disease (CVD). The ongoing exploration of new antiplatelet agents with minimal bleeding effects is crucial, including the investigation of potential compounds derived from natural products. This study intended to evaluate the antiplatelet effects of a combined extract of sappan wood (Caesalpinia sappan L.) and red ginger (Zingiber officinale var. Rubrum) in high-fat diet-(HFD)-induced rats. Methods: Eighteen male Wistar rats were grouped into six groups (n = 3): control, negative, positive, and three groups of various combinations of extracts. All groups, excluding the control group, were fed an HFD for 8 weeks. In the eighth week, the control and negative groups were given carboxyl methyl cellulose (CMC) 0.5%, the positive control group was administered aspirin, and the other three groups were administered the combination extract of sappan wood and red ginger at various doses for 2 weeks. Blood samples were collected to assess the levels of hyperlipidemia and platelet hyperactivity markers by enzyme-linked immunosorbent assay (ELISA). The physiological effects of platelet hyperactivity were evaluated using the tail bleeding assay. Results: HFD-induced hypertriglyceridemia and hypercholesterolemia synergistically enhanced platelet hyperactivity after 8 weeks of induction. Interestingly, administration of all doses of the combined extract for 2 weeks significantly decreased the platelet activation markers P-selectin, RANTES, and PCSK9 in a dose-dependent manner compared with the negative control. In addition, the combination of sappan wood and red ginger extract at dose 3 (sappan wood:red ginger: 200:800 mg/200 bw/day) significantly extended the bleeding time of rats (p < 0.05) compared to the negative control. Conclusion: Collectively, our results highlight the antiplatelet effect of a combination of sappan wood and red ginger extract in HFD-fed rats.

Sappanone A ameliorated imiquimod-induced psoriasis-like dermatitis in BALB/c mice via suppressing Mmp8 expression and IL-17 signaling pathway

Psoriasis is a prevalent immune-mediated inflammatory skin disease characterized by excessive abnormal proliferation of keratinocytes and infiltration of immune cells, which have significant impact on the life quality of individuals. Although biological agents and small molecule targeted drugs have brought significant clinical benefits to psoriasis patients, adverse reactions and high prices remains key issues in clinical medication of psoriasis, while natural product monomers possess high efficiency, low toxicity, anti-inflammatory and immunomodulatory properties, and bring new hope for the clinical treatment of psoriasis. Sappanone A (SA), a small molecule compound isolated from Caesalpinia sappan L, exhibits significant anti-inflammatory properties in various models, such as kidney inflammation and LPS-induced mice inflammation. Among these effects, the anti-inflammatory property of SA has received significant attention. In our study, we found that SA exhibited anti-proliferation and anti-inflammatory effects in HaCaT cells, and significantly alleviated imiquimod-induced psoriasis-like skin lesions via the inhibition of the excessive proliferation of keratinocytes and the infiltration of lymphocytes. Furthermore, the combinational analysis of network pharmacology and transcriptome sequencing revealed that SA exerted anti-psoriasis effects by inhibiting the matrix metalloproteinase 8 (Mmp8) expression and IL-17 pathway activation. In summary, we have first demonstrated that SA can be used as a novel anti-psoriasis drug, which may provide a novel strategy for the clinical treatment of psoriasis.

Role of Trimetazidine in Ameliorating Endothelial Dysfunction: A Review

Endothelial dysfunction is a hallmark of cardiovascular diseases, contributing to impaired vasodilation, altered hemodynamics, and atherosclerosis progression. Trimetazidine, traditionally used for angina pectoris, exhibits diverse therapeutic effects on endothelial dysfunction. This review aims to elucidate the mechanisms underlying trimetazidine's actions and its potential as a therapeutic agent for endothelial dysfunction and associated cardiovascular disorders. Trimetazidine enhances vasodilation and hemodynamic function by modulating endothelial nitric oxide synthase activity, nitric oxide production, and endothelin-1. It also ameliorates metabolic parameters, including reducing blood glucose, mitigating oxidative stress, and dampening inflammation. Additionally, trimetazidine exerts antiatherosclerotic effects by inhibiting plaque formation and promoting its stability. Moreover, it regulates apoptosis and angiogenesis, fostering endothelial cell survival and neovascularization. Understanding trimetazidine's multifaceted mechanisms underscores its potential as a therapeutic agent for endothelial dysfunction and associated cardiovascular disorders, warranting further investigation for clinical translation.

Cell Staining Microgels Derived from a Natural Phenolic Dye: Hematoxylin Has Intriguing Biomedical Potential

Hematoxylin (HT) as a natural phenolic dye compound is generally used together with eosin (E) dye as H&E in the histological staining of tissues. Here, we report for the first time the polymeric particle preparation from HT as poly(Hematoxylin) ((p(HT)) microgels via microemulsion method in a one-step using a benign crosslinker, glycerol diglycidyl ether (GDE). P(HT) microgels are about 10 µm and spherical in shape with a zeta potential value of -34.6 ± 2.8 mV and an isoelectric point (IEP) of pH 1.79. Interestingly, fluorescence properties of HT molecules were retained upon microgel formation, e.g., the fluorescence emission intensity of p(HT) at 343 nm was about 2.8 times less than that of the HT molecule at λex: 300 nm. P(HT) microgels are hydrolytically degradable and can be controlled by using an amount of crosslinker, GDE, e.g., about 40%, 20%, and 10% of p(HT) microgels was degraded in 15 days in aqueous environments for the microgels prepared at 100, 200, and 300% mole ratios of GDE to HT, respectively. Interestingly, HT molecules at 1000 mg/mL showed 22.7 + 0.4% cell viability whereas the p(HT) microgels exhibited a cell viability of 94.3 + 7.2% against fibroblast cells. Furthermore, even at 2000 mg/mL concentrations of HT and p(HT), the inhibition% of α-glucosidase enzyme were measured as 93.2 ± 0.3 and 81.3 ± 6.3%, respectively at a 0.03 unit/mL enzyme concentration, establishing some potential application of p(HT) microgels for neurogenerative diseases. Moreover, p(HT) microgels showed two times higher MBC values than HT molecules, e.g., 5.0 versus 2.5 mg/mL MIC values against Gram-negative E. coli and Gram-positive S. aureus, respectively.

Aromatic Plants as Potential Resources to Combat Osteoarthritis

Osteoarthritis, which affects an estimated 10% of men and 18% of women over the age of 60 and is increasing in genetic prevalence and incidence, is acknowledged as the condition that degrades the quality of life for older adults in the world. There is currently no known treatment for osteoarthritis. The majority of therapeutic methods slow the progression of arthritis or treat its symptoms, making effective treatment to end the degenerative process of arthritis elusive. When non-pharmacological therapy is ineffective, various pharmacological therapies may be used to treat osteoarthritis. Pharmacological therapy, however, can have major adverse effects and be very expensive. As a result, alternative remedies have been researched. The promise for the safe and efficient management of osteoarthritis has been demonstrated by herbal remedies. Experimental research suggests that herbal extracts and compounds can reduce inflammation, inhibit catabolic processes, and promote anabolic processes that are important for treating osteoarthritis. Due to their therapeutic and innate pharmacological qualities, aromatic herbs are frequently employed as herbal remedies. Recent research has shown that aromatic plants have the potency to treat osteoarthritis. Additionally, complex mixtures of essential oils and their bioactive ingredients, which have anti-inflammatory and antioxidant properties and are obtained from aromatic plants, are frequently utilized as complementary therapies for osteoarthritis. To establish new study avenues, the advantageous anti-osteoarthritic effects of aromatic herbal medicines, including plants, essential oils, and their bioactive components, are extensively discussed.

A Comprehensive Review on Bioactive Compounds Found in Caesalpinia sappan

Sappan wood (Caesalpinia sappan) is a tropical hardwood tree found in Southeast Asia. Sappan wood contains a water-soluble compound, which imparts a red color named brazilin. Sappan wood is utilized to produce dye for fabric and coloring agents for food and beverages, such as wine and meat. As a valuable medicinal plant, the tree is also known for its antioxidant, anti-inflammatory, and anticancer properties. It has been observed that sappan wood contains various bioactive compounds, including brazilin, brazilein, sappan chalcone, and protosappanin A. It has also been discovered that these substances have various health advantages; they lower inflammation, enhance blood circulation, and are anti-oxidative in nature. Sappan wood has been used as a medicine to address a range of illnesses, such as gastrointestinal problems, respiratory infections, and skin conditions. Studies have also suggested that sappan wood may have anticarcinogenic potential as it possesses cytotoxic activity against cancer cells. Based on this, the present review emphasized the different medicinal properties, the role of phytochemicals, their health benefits, and several food and nonfood applications of sappan wood. Overall, sappan wood has demonstrated promising medicinal properties and is an important resource in traditional medicine. The present review has explored the potential role of sappan wood as an essential source of bioactive compounds for drug development.

Cardioprotective Properties of Kaempferol: A Review

Cardiac diseases, such as myocardial infarction and heart failure, have become a major clinical problem globally. The accumulating data demonstrate that bioactive compounds with antioxidant and anti-inflammatory properties have favorable effects on clinical problems. Kaempferol is a flavonoid found in various plants; it has demonstrated cardioprotective properties in numerous cardiac injury models. This review aims to collate updated information regarding the effects of kaempferol on cardiac injury. Kaempferol improves cardiac function by alleviating myocardial apoptosis, fibrosis, oxidative stress, and inflammation while preserving mitochondrial function and calcium homeostasis. However, the mechanisms of action of its cardioprotective properties remain unclear; therefore, elucidating its action could provide insight into directions for future studies.

Key circRNAs, lncRNAs, and mRNAs of ShenQi Compound in Protecting Vascular Endothelial Cells From High Glucose Identified by Whole Transcriptome Sequencing

ABSTRACT

Vascular endothelial cells, which make up the inner wall of blood arteries, are susceptible to damage from oxidative stress and apoptosis caused by hyperglycemia. According to certain reports, noncoding RNAs are involved in controlling oxidative stress and apoptosis. ShenQi Compound (SQC), a traditional herbal remedy, has been successfully treating diabetic vascular disease in China for more than 20 years. Although it is well established that SQC protects the vascular endothelium, the molecular mechanism remains unknown. Goto-Kakizaki rats, spontaneous type II diabetes rats, that consistently consume a high-fat diet were chosen as model animals. Six groups (control group, model group, metformin group, and 7.2 g/kg/d SQC group, 14.4 g/kg/d SQC group, and 28.8 g/kg/d SQC group) were included in this work, 15 rats each group. The approach of administration was gavage, and the same volume (5.0 mL/kg/d) was given in each group, once a day, 12 weeks. The thoracic aortas were removed after the rats were sacrificed. Oxidative reduction profile in thoracic aorta, histopathological observation of thoracic aorta, endothelial cell apoptosis in thoracic aorta, whole transcriptome sequencing, bioinformatic analyses, and qRT-PCR were conducted. As a result, SQC prevented the oxidative stress and apoptosis induced by a high glucose concentration. Under hyperglycemia condition, noncoding RNAs, including 1 downregulated novel circRNA (circRNA.3121), 3 downregulated lncRNAs (Skil.cSep08, Shawso.aSep08-unspliced, and MSTRG.164.2), and 1 upregulated mRNA (Pcdh17), were clearly reverse regulated by SQC. SQC plays a role in protecting vascular endothelial cells from high glucose mainly by mediating ncRNA to inhibit cell apoptosis and oxidative stress.

Role of Trientine in Hypertrophic Cardiomyopathy: A Review of Mechanistic Aspects

Abnormality in myocardial copper homeostasis is believed to contribute to the development of cardiomyopathy. Trientine, a copper-chelating drug used in the management of patients with Wilson's disease, demonstrates beneficial effects in patients with hypertrophic cardiomyopathy. This review aims to present the updated development of the roles of trientine in hypertrophic cardiomyopathy. The drug has been demonstrated in animal studies to restore myocardial intracellular copper content. However, its mechanisms for improving the medical condition remain unclear. Thus, comprehending its mechanistic aspects in cardiomyopathy is crucial and could help to expedite future research.

Molecular mechanisms of sacubitril/valsartan in cardiac remodeling

Cardiovascular diseases have become a major clinical burden globally. Heart failure is one of the diseases that commonly emanates from progressive uncontrolled hypertension. This gives rise to the need for a new treatment for the disease. Sacubitril/valsartan is a new drug combination that has been approved for patients with heart failure. This review aims to detail the mechanism of action for sacubitril/valsartan in cardiac remodeling, a cellular and molecular process that occurs during the development of heart failure. Accumulating evidence has unveiled the cardioprotective effects of sacubitril/valsartan on cellular and molecular modulation in cardiac remodeling, with recent large-scale randomized clinical trials confirming its supremacy over other traditional heart failure treatments. However, its molecular mechanism of action in cardiac remodeling remains obscure. Therefore, comprehending the molecular mechanism of action of sacubitril/valsartan could help future research to study the drug's potential therapy to reduce the severity of heart failure.

Inhibition of Myocardial Cell Apoptosis Is Important Mechanism for Ginsenoside in the Limitation of Myocardial Ischemia/Reperfusion Injury

Ischemic heart disease has a high mortality, and the recommended therapy is reperfusion. Nevertheless, the restoration of blood flow to ischemic tissue leads to further damage, namely, myocardial ischemia/reperfusion injury (MIRI). Apoptosis is an essential pathogenic factor in MIRI, and ginsenosides are effective in inhibiting apoptosis and alleviating MIRI. Here, we reviewed published studies on the anti-apoptotic effects of ginsenosides and their mechanisms of action in improving MIRI. Each ginsenoside can regulate multiple pathways to protect the myocardium. Overall, the involved apoptotic pathways include the death receptor signaling pathway, mitochondria signaling pathway, PI3K/Akt signaling pathway, NF-κB signaling pathway, and MAPK signaling pathway. Ginsenosides, with diverse chemical structures, regulate different apoptotic pathways to relieve MIRI. Summarizing the effects and mechanisms of ginsenosides contributes to further mechanism research studies and structure-function relationship research studies, which can help the development of new drugs. Therefore, we expect that this review will highlight the importance of ginsenosides in improving MIRI via anti-apoptosis and provide references and suggestions for further research in this field.

The phytochemical brazilin suppress DNMT1 expression by recruiting p53 to its promoter resulting in the epigenetic restoration of p21 in MCF7cells

BACKGROUND

Cancer is an outcome of uncontrolled cell division eventually associated with dysregulated epigenetic mechanisms, including DNA methylation. DNA methyltransferase 1 is ubiquitously expressed in the proliferating cells and is essential for the maintenance of DNA methylation. It causes the abnormal silencing of tumor suppressor genes in human cancer which is necessary for proliferation, cell cycle progression, and survival. DNMT1 is involved in tumorigenesis of several cancers, its upregulation potentially upscale the promoter level inactivation of transcription of a tumor inhibitory gene by introducing repressive methylation marks on the CpG islands. This epigenetic perturbation caused by DNMT is targeted for cancer therapeutics.

PURPOSE

To demonstrate the proliferative inhibitory potential of brazilin in human breast cancer cell line (MCF-7) with concurrent mitigation of DNMT1 functional expression and to understand its effect on downstream targets like cell cycle inhibitor p21.

STUDY DESIGN/ METHODS

The impact of brazilin on the growth and proliferation of the MCF-7 cells was determined using the XTT assay. The global DNA 5-methyl cytosine methylation pattern was analyzed upon brazilin treatment. The gene and protein expression of DNMTs were determined with quantitative RTPCR and western blots respectively. The potential binding sites of transcription factors in the human DNMT1 promoter were predicted using the MatInspector tool on the Genomatix software. The chromatin immunoprecipitation (ChIP) assay was performed to demonstrate the transcription factors occupancy at the promoter. Methylation of promoter CpG islands was determined by the methylation-specific PCR (MSP) upon brazilin treatment. The molecular docking of the human DNMT1 with brazilin (ligand) was performed using the Schrödinger suite.

RESULTS

The heterotetracyclic compound brazilin, present in the wood of Caesalpinia sappan, inhibited the proliferation of the human breast cancer cell line (MCF-7) and reduced the DNMT1 expression with a decrease in global DNA methylation. Brazilin, by activating p38 MAPK and elevating p53 levels within the exposed cells. The elevated level of p53 enriched the occupancy at binding sites within 200 bp upstream to the transcription start site in the DNMT1 promoter, resulting in reduced DNMT1 gene expression. Furthermore, the brazilin restored the p21 levels in the exposed cells as the CpGs in the p21 promoter (-128 bp/+17 bp) were significantly demethylated as observed in the methylation-specific PCR (MSP).

CONCLUSION

Highly potential anti-proliferative molecule brazilin can modulate the DNMT1 functional expression and restore the cell cycle inhibitor p21expression. We propose that brazilin can be used in therapeutic interventions to restore the deregulated epigenetic mechanisms in cancer.