Next Article in Journal
Expression of 15-PGDH Regulates Body Weight and Body Size by Targeting JH in Honeybees (Apis mellifera)
Previous Article in Journal
Bacteremia Caused by a Putative Novel Species in the Genus Erwinia: A Case Report and Genomic Analysis
Previous Article in Special Issue
A Prospective Clinical Study of Ferric Citrate Hydrate for Chronic Heart Failure with Iron Deficiency Anemia
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Life
Volume 15
Issue 8
10.3390/life15081229
life-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Hibiscus syriacus L. Exhibits Cardioprotective Activity via Anti-Inflammatory and Antioxidant Mechanisms in an In Vitro Model of Heart Failure

by
Hung-Hsin Chao
1,2,†,
Tzu-Hurng Cheng
3,†,
Chun-Chao Chen
4,5,
Ju-Chi Liu
4,5,
Jin-Jer Chen
6,7 and
Li-Chin Sung
4,5,*
1
Division of Cardiovascular Surgery, Department of Surgery, Shin Kong Wu Ho-Su Memorial Hospital, Taipei City 111045, Taiwan
2
School of Medicine, College of Medicine, Catholic Fu-Jen University, New Taipei City 24352, Taiwan
3
Department of Biochemistry, School of Medicine, College of Medicine, China Medical University, Taichung City 404328, Taiwan
4
Division of Cardiology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City 23561, Taiwan
5
Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei City 11002, Taiwan
6
Division of Cardiology, Department of Internal Medicine and Graduate Institute of Clinical Medical Science, China Medical University Hospital, Taichung City 404327, Taiwan
7
Institute of Biomedical Sciences, Academia Sinica, Taipei City 11529, Taiwan
*
Author to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Life 2025, 15(8), 1229; https://doi.org/10.3390/life15081229 (registering DOI)
Submission received: 3 July 2025 / Revised: 27 July 2025 / Accepted: 31 July 2025 / Published: 3 August 2025
(This article belongs to the Special Issue Advancements in Heart Failure Research: 2nd Edition)
Browse Figures
Versions Notes

Abstract

Hibiscus syriacus L. (HS), native to Eastern and Southern Asia, has been traditionally used in Asian herbal medicine for its anticancer, antimicrobial, and anti-inflammatory properties. Despite these recognized bioactivities, its potential cardioprotective effects, particularly in the setting of heart failure (HF), remain largely unexplored. This study aimed to investigate the effects of HS extracts and its bioactive constituents on angiotensin II (Ang II)-induced cardiac injury using an in vitro model with H9c2 rat cardiomyocytes. Cells exposed to Ang II were pretreated with HS extracts, and assays were performed to assess cell viability, reactive oxygen species (ROS) generation, protein synthesis, and secretion of inflammatory mediators, including tumor necrosis factor-alpha, interleukin 1β (IL-1β), and interleukin 6 (IL-6), as well as chemokine (CCL20) and HF-related biomarkers, such as brain natriuretic peptide (BNP) and endothelin-1. The results demonstrated that HS extracts significantly and dose-dependently attenuated Ang II-induced ROS accumulation and suppressed the secretion of pro-inflammatory cytokines, chemokines, BNP, and endothelin-1. Additionally, HS and its purified components inhibited Ang II-induced protein synthesis, indicating anti-hypertrophic effects. Collectively, these findings highlight the antioxidative, anti-inflammatory, and antihypertrophic properties of HS in the context of Ang II-induced cardiac injury, suggesting that HS may represent a promising adjunctive therapeutic candidate for HF management. Further in vivo studies and mechanistic investigations are warranted to validate its clinical potential.

1. Introduction

1.1. Heart Failure: Global Burden and Therapeutic Challenges

Heart failure (HF) is a major global health concern, characterized by impaired myocardial function that contributes to elevated morbidity and mortality [1,2]. Its prevalence is rising due to aging populations and increases in cardiovascular risk factors [2,3,4,5,6]. Beyond clinical impact, HF imposes significant economic burdens, highlighting the urgent need for novel, effective, and well-tolerated therapeutic strategies [7]. Although current first-line therapies such as renin–angiotensin–aldosterone system (RAAS) inhibitors and β-blockers offer symptomatic relief, their benefits are often constrained by adverse effects, including hyperkalemia and hypotension [8]. Moreover, conventional therapeutic approaches often lack efficacy in modulating the core pathophysiological processes that drive the progression of HF [8,9,10]. This underscores a critical need for alternative or adjunctive approaches that address both the symptomatic and mechanistic aspects of the disease.

1.2. Natural Products in Cardiovascular Therapy: A Focus on Hibiscus syriacus L.

Natural compounds derived from medicinal plants have garnered increasing attention as complementary therapeutic agents, offering multitarget efficacy with favorable safety profiles [11,12,13,14,15]. In particular, Hibiscus spp. have been associated with antihypertensive, antioxidant, and anti-inflammatory effects [13]. Among them, Hibiscus syriacus L. (HS), commonly known as the Rose of Sharon (Figure 1), has a long history of use in traditional Asian medicine for a wide range of indications, including cardiovascular disorders, abdominal pain, skin diseases, and microbial infections [14,15,16]. Pharmacological studies have revealed that HS exerts antioxidative, anti-inflammatory, and vasodilatory effects (Table 1). Its bioactive constituents, such as flavonoids, phenolic acids, and anthocyanins, are known to modulate key pathological processes implicated in HF, including reactive oxygen species (ROS) production, inflammatory signaling, endothelial dysfunction, and myocardial remodeling [3,4,5,14,15,16,17]. In vitro evidence further supports its broader therapeutic applications, demonstrating anticancer, anti-osteoporotic, and sleep-improving properties via mechanisms involving Notch, GSK-3β, and autophagy signaling [3,4,15,18,19]. These findings position HS as a promising botanical candidate for cardiovascular protection, particularly in HF.

1.3. Rationale, Research Gaps, and Study Objectives

Despite encouraging preclinical data, the therapeutic potential of HS in the context of HF remains underexplored, with limited understanding of its molecular mechanisms and clinical applicability [29,30]. There is a need to delineate how HS modulates key HF-related pathways and biomarkers, including oxidative stress and proinflammatory mediators such as tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and C-C motif chemokine ligand 20 (CCL20), as well as brain natriuretic peptide (BNP) and endothelin-1 (ET-1) [18,21,31,32,33]. This study aims to evaluate the cardioprotective effects of HS extracts using an in vitro model, focusing on its antioxidant and anti-inflammatory activities. By constructing a conceptual framework around HS as a novel plant-based intervention for HF, this research provides a foundational step toward future translational and clinical development.

2. Materials and Methods

2.1. Selection and Preparation of HS Extracts

The flowers and stems of HS were collected from Beitun District, Taichung City, Taiwan. Botanical identification was performed by a qualified taxonomist based on morphological characteristics and regional floristic references. Although a voucher specimen was not deposited, the botanical identity and consistency of the plant material were verified through visual inspection and taxonomic assessment, in accordance with established practices [5,15]. To prepare the extracts, both maceration and Soxhlet methods were employed to optimize yield and preserve bioactivity. Air-dried and pulverized HS flowers and stems were first macerated in 95% ethanol at ambient temperature (22–25 °C) for 72 h with intermittent agitation. The resulting ethanol filtrate was concentrated under reduced pressure at 40 °C to produce the crude ethanol extract (HS-EtOH). This extract was subsequently partitioned using solvents of increasing polarity—hexane (HS-Hex), ethyl acetate (HS-EA), n-butanol (HS-BuOH), and distilled water (HS-H2O)—to fractionate compounds based on solubility and polarity, in accordance with established phytochemical fractionation protocols [18,21]. In parallel, Soxhlet extraction was conducted using 10 g of dried HS stem powder for each solvent. Extraction was performed over 6 h at controlled temperatures specific to each solvent: 60 °C for ethanol, 50 °C for hexane, 55 °C for ethyl acetate, and 65 °C for n-butanol. Aqueous extraction was achieved through refluxing in distilled water at 90 °C for 2 h. All extracts were subsequently filtered, concentrated using rotary evaporation, and stored at −20 °C until further use. Extraction yields were calculated relative to the initial dry weight of the plant material. Preliminary phytochemical analysis confirmed the presence of key secondary metabolites, including flavonoids, anthocyanins, and polyphenols, consistent with previously reported profiles of HS extracts [23,28]. This integrative and stepwise extraction strategy was designed to maintain the stability of thermolabile compounds and to enrich fractions with potential antioxidant and anti-inflammatory activities, as supported by earlier investigations into the pharmacological properties of HS-derived constituents [19,22].

2.2. Cell Viability Test

Cell viability was evaluated using the Cell Counting Kit-8 assay to determine the cytotoxic threshold and optimal concentration range of HS extract for subsequent mechanistic studies. H9c2 cells were seeded into 96-well plates at a density of 8 × 103 cells per well and incubated for 24 h to allow cell attachment. Thereafter, cells were treated with varying concentrations of HS extracts (10, 30, 50, 100, 150, and 200 μg/mL) for an additional 24 h. Following treatment, 10 μL of WST-8 reagent [2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt] was added to each well, and plates were incubated at 37 °C for 4 h. The absorbance was measured at 450 nm using a microplate reader (Bio-Rad, Hercules, CA, USA), and cell viability was calculated relative to untreated control wells.

2.3. Experimental Design for Assessing ROS Production

To explore the role of oxidative stress in HS-mediated cardioprotection, ROS levels were quantified in H9c2 cells following Ang II stimulation and HS pretreatment.

2.3.1. Materials

Tissue culture reagents, including fetal bovine serum and Dulbecco’s modified Eagle’s medium (DMEM), were obtained from Invitrogen (Carlsbad, CA, USA). The ROS-sensitive fluorescent dye, 2′,7′-dichlorofluorescin diacetate (DCFH-DA), was procured from Serva Co. (Heidelberg, Germany). Enzyme-linked immunosorbent assay (ELISA) kits were purchased from Abcam (Cambridge, UK).

2.3.2. H9c2 Cell Culture

The H9c2 cell line, an immortalized rat embryonic cardiac myoblast line, was sourced from the American Type Culture Collection (ATCC CRL-1446; Rockville, MD, USA). The characteristics of this cell line have been previously described [34]. The cells were cultured in DMEM supplemented with 10% fetal bovine serum, all purchased from Sigma-Aldrich. The cell cultures were maintained in a humidified incubator at 37 °C with 5% CO2.

2.3.3. Flow Cytometric Assay of 2′,7′-Dichlorodihydrofluorescein Oxidation

To assess intracellular ROS levels, cells were incubated in culture medium containing 30 µM DCFH-DA for 1 h prior to treatment with HS or Ang II (100 nM), following established protocols [35,36]. The same concentration of DCFH-DA was maintained during treatment. After incubation, cells were washed with phosphate-buffered saline (PBS), detached via brief trypsinization, and analyzed for DCF fluorescence. DCFH-DA is hydrolyzed by cellular esterases to DCFH, which is oxidized to fluorescent DCF in the presence of ROS. The fluorescence intensity of DCF, indicative of intracellular ROS levels, was measured using a fluorescence spectrophotometer, with excitation and emission wavelengths set at 475 and 525 nm, respectively. Following fluorescence measurements, cell counts were determined using an automated cell counter (S.ST.II/ZM, Coulter Electronics Ltd., Miami, FL, USA), and ROS levels were normalized to cell number. This assay provided mechanistic insight into whether HS exerts antioxidant effects in Ang II-stimulated cardiomyocytes, a known contributor to HF pathogenesis.

2.4. Experimental Design for Assessing Ang II-Stimulated Protein Synthesis

To further delineate whether the antioxidant effect of HS translates into functional protection, we next assessed cardiomyocyte hypertrophy by measuring protein synthesis. Protein synthesis was evaluated by measuring the incorporation of [3H]leucine into acid-insoluble protein, a validated marker of hypertrophic response [37]. Cardiomyocytes were incubated in serum-free medium containing 1.0 μCi/mL [3H]leucine. Following incubation, the cells were harvested by treatment with 5% trichloroacetic acid at 4 °C and then solubilized in 0.1 N NaOH. The rate of [3H]leucine incorporation was quantified using liquid scintillation spectrometry. This experiment aimed to investigate whether the modulation of ROS by HS is associated with downstream changes in hypertrophic signaling.

2.5. Experimental Design for Assessing the Secretion of the Selected Inflammatory Cytokines, Chemokines, and HF Risk Biomarkers

Given the key role of inflammation in HF, we subsequently examined the effects of HS on the secretion of inflammatory cytokines and HF-associated biomarkers. H9c2 cells were pretreated with or without HS extracts or its bioactive components for 12 h, followed by stimulation with Ang II (100 nM) for 24 h. After centrifugation at 1000 rpm for 10 min, supernatants were collected to measure levels of TNF-α, IL-1β, IL-6, CCL20, BNP, and ET-1. These biomarkers were quantified using commercially available ELISA kits (Abcam, Cambridge, UK), following the manufacturer’s instructions [38]. These measurements were intended to confirm whether HS attenuates inflammatory and neurohormonal responses associated with HF pathophysiology.

3. Results

3.1. HS Extractions

3.1.1. Bioactive Compounds and Their Therapeutic Potential

To explore the pharmacological potential of HS extraction, we first characterized its chemical composition. To maximize the recovery of bioactive constituents from HS, an ethanol-first extraction strategy was employed. Ethanol was selected as the initial solvent due to its broad-spectrum solubility, which enables efficient extraction of both polar and non-polar phytochemicals, including flavonoids, anthocyanins, sterols, and polyphenols [5,26]. This approach is consistent with previous studies demonstrating the pharmacological relevance of ethanol-based extracts in antioxidant, anti-inflammatory, and cytotoxic applications [15,21]. Following ethanol maceration, the crude extract (HS-EtOH) was subjected to sequential solvent partitioning using hexane (HS-Hex), ethyl acetate (HS-EA), n-butanol (HS-BuOH), and distilled water (HS-H2O), allowing for polarity-based fractionation (Figure 2). This stepwise method was designed to isolate distinct classes of compounds, as previously described in studies investigating HS-derived anthocyanins, sterols, and triterpenoids with diverse bioactivities [22,27]. The extraction yields, calculated based on dry weight, were as follows: HS-Hex (2.3%), HS-EA (4.7%), HS-BuOH (6.1%), and HS-H2O (8.4%). These values reflect solvent-specific recovery efficiencies and align with prior reports on HS phytochemical distribution [17,28]. Fourier-transform infrared spectroscopy confirmed the presence of functional groups characteristic of phenolic acids, sterols, and flavonoids. Specific compounds, including β-sitosterol, 2-linoleodistearin, linoleic acid, syriacusin B, and tricetin 3′,5′-dimethyl ester, were identified using high-performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR) spectroscopy (Figure 3). HPLC analysis was performed using a reverse-phase C18 column (250 mm × 4.6 mm, 5 µm particle size), with a gradient mobile phase consisting of methanol and water (0.1% formic acid), at a flow rate of 1.0 mL/min and detection wavelength of 254 nm. Elution profiles were monitored over a 30 min run time. Structural elucidation of isolated compounds was confirmed by 1H and 13C NMR spectroscopy using a Bruker 500 MHz instrument in CDCl3 or DMSO-d6 as solvents, with chemical shifts referenced to internal TMS. These spectral data supported the identification of key bioactive constituents previously associated with antioxidant, anti-inflammatory, and cytotoxic activities in HS [15,22,27]. Collectively, these findings supported the therapeutic relevance of HS as a natural source of multifunctional bioactive compounds, with potential applications in cardiovascular, dermatological, and metabolic health.

3.1.2. Effects of HS Extracts on H9c2 Cardiomyocyte Viability

To determine the non-toxic range for downstream functional assays, the treatment of cultured H9c2 cardiomyocytes with HS extracts at concentrations of 10–50 µg/mL for 24 h did not significantly affect cell viability (HS-Hex, HS-EA, and HS-H2O; Figure 4).

3.2. Effects of HS Extracts on ROS Production, Protein Synthesis, and Secretion of Inflammatory Cytokines, Chemokines, and HF Risk Biomarkers

3.2.1. Inhibition of Ang II-Induced Redox Signaling and Hypertrophy In Vitro

We next examined the antioxidant capacity of HS extracts in an in vitro model of Ang II-induced oxidative stress. Treatment of cardiomyocytes with HS extracts resulted in a concentration-dependent reduction in Ang II-increased ROS levels compared with Ang II-treated controls (Figure 5). Notably, higher concentrations of HS extracts significantly attenuated ROS production, indicating their antioxidant activity. Statistical analysis confirmed a clear dose-dependent relationship between HS extract concentration and ROS inhibition. These findings suggested that HS extracts may possess antioxidant properties that contribute to their cardioprotective effects in HF. Given the established role of ROS in promoting hypertrophy, cardiomyocyte hypertrophy, a hallmark of HF, is characterized by increased protein synthesis. In this study, cardiomyocytes treated with Ang II (100 nM, 24 h) exhibited increased protein synthesis compared with control cells (Figure 6A). To investigate the antihypertrophic effects of HS extracts, cardiomyocytes were treated with various HS extracts, including HS-Hex, HS-EA, and HS-H2O. This treatment significantly reduced Ang II-induced protein synthesis compared with cells treated with Ang II alone (Figure 6A). Moreover, cardiomyocytes pretreated with pure compounds isolated from HS extracts (HS-324, HS-3253, HS-363, and HS-3271 at 6.25 and 10 μM) for 12 h did not exhibit an increase in Ang II-induced protein synthesis, in contrast to the Ang II-stimulated control groups (Figure 6B). These results indicated that pretreatment with HS extracts or their isolated components may effectively prevent Ang II-induced cardiomyocyte hypertrophy.

3.2.2. Inhibition of Ang II-Induced Inflammatory Cytokine and Chemokine Secretion In Vitro

As inflammation is a major contributor to HF progression, we next assessed the anti-inflammatory potential of HS extracts. As demonstrated in Figure 7, pretreatment with HS extracts effectively inhibited the secretion of inflammatory cytokines and chemokines, including TNF-α, IL-1β, IL-6, and CCL20, in response to 2 h Ang II (100 nM) stimulation. This finding indicated that HS extracts exert anti-inflammatory effects by suppressing the Ang II-induced production of inflammatory mediators. Such effects may contribute to the potential cardioprotective benefits of HS in HF.

3.2.3. Inhibition of Ang II-Induced HF Risk Biomarker Secretion In Vitro

To evaluate whether HS extracts influence key markers of HF pathophysiology, we quantified the release of BNP and ET-1 following Ang II exposure. As illustrated in Figure 8, pretreatment with HS extracts significantly reduced the secretion of biomarkers for HF risk, including ET-1 and BNP, in response to a 2 h Ang II (100 nM) stimulation. This finding suggested that HS extracts can effectively suppress Ang II-induced production of HF risk biomarkers, further supporting their potential role as cardioprotective agents and underscoring their therapeutic relevance in HF management.

4. Discussion

4.1. Interpretation of Experimental Results and Mechanistic Interpretations

Inflammation and oxidative stress are pivotal contributors to the pathogenesis of HF [32,33]. The present findings highlight the therapeutic potential of HS extracts in HF management. The observed reduction in ROS production reflects the potent antioxidant capacity of HS, which may help to alleviate oxidative stress—a hallmark of HF [20,21]. HS extracts also significantly suppressed the secretion of inflammatory cytokines in a dose-dependent manner, further reinforcing their cardioprotective potential [22]. Excessive ROS generation can lead to DNA damage, lipid peroxidation, and cell death, thereby promoting myocardial remodeling and HF progression [35,40]. Inflammation is also widely recognized as a central pathophysiological factor in both acute and chronic HF and serves as an independent predictor of poor prognosis, regardless of left ventricular systolic function [41,42]. Elevated levels of inflammatory cytokines are strongly associated with increased HF severity [42,43], with TNF-α, IL-1, IL-6, IL-8, IL-10, IL-18, and IL-33 identified as key mediators in HF pathogenesis [32,42,43]. Notably, TNF-α has been strongly implicated in cardiac inflammation and correlates with both HF severity and mortality when serum levels are elevated [44]. Chemokines, which mediate immunoregulatory and inflammatory responses, also contribute to HF progression [45]. Serum CCL20 levels have been associated with ischemic heart disease [46] and are considered potential predictors of HF severity and prognosis [44]. Furthermore, TNF-α-induced upregulation of CCL20 expression in human cardiac fibroblasts suggests a potential pathogenic link between these molecules in cardiac inflammation [44]. Biomarkers such as BNP, ET-1, hsTn1, and ST2 are widely used to assess HF risk and prognosis [31]. Elevated discharge levels of these biomarkers in HF patients are associated with increased risks of readmission and mortality compared with baseline values.
Our findings are consistent with those of studies identifying oxidative stress and inflammation as critical therapeutic targets in HF [18]. The dose-dependent effects observed in our study suggest that HS modulates key cellular pathways involved in HF pathophysiology. Future investigations are warranted to further elucidate the precise molecular mechanisms underlying these cardioprotective effects.

4.2. Comparison with Previous Studies

Our results align with previous findings that underscore the therapeutic potential of HS extracts [18,21]. In BV2 microglia cells, anthocyanins isolated from HS petals exhibited strong anti-inflammatory and antioxidant effects by attenuating endoplasmic reticulum stress and NF-κB signaling, reducing mitochondrial ROS production, and suppressing NLRP3 inflammasome-mediated IL-1β and IL-18 secretion [23]. Similarly, in H2O2-stimulated HaCaT keratinocytes, these anthocyanins activated the nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 pathways, conferring cytoprotective effects [21]. In lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages, HS-derived anthocyanins have also been shown to downregulate inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), reduce pro-inflammatory cytokine levels (e.g., TNF-α, IL-6, and IL-12), and inhibit NF-κB activation [22]. Studies on Ang II signaling pathways in cardiomyocytes have identified key pathways contributing to HF progression, including redox-sensitive ERK1/2, p38, and NF-κB pathways driving Ang II-induced ROS production [47], ER stress triggered by excessive ROS [48], and activation of the NLRP3 inflammasome leading to elevated IL-1β and IL-18 levels [49]. Our findings extend this growing body of evidence by providing mechanistic insights into HS-mediated cardioprotection. Specifically, the data support the antioxidant and anti-inflammatory actions of HS, contributing to the attenuation of HF-related pathologies. This study broadens the current understanding of the molecular targets of HS and supports its development as a natural therapeutic candidate for HF management.

4.3. Implications of Findings in the Context of HF Management

The present findings suggest that HS extracts may attenuate HF progression through the reduction of oxidative stress, suppression of inflammatory responses, and limitation of myocardial remodeling [21]. Several key inflammatory mediators and HF biomarkers, including TNF-α, IL-1β, IL-6, and BNP, are known to be produced directly by cardiomyocytes [42,50]. The chemokine CCL20, initially identified in the liver, lung, and appendix, is now recognized as being expressed in various tissues and has been linked to ventricular dysfunction and the severity of ischemic heart disease [45,46,51]. ET-1, discovered over 30 years ago as the first endothelium-derived contracting factor, plays a key role in inflammatory signaling, particularly through interactions with TNF-α, IL-1, and IL-6 [52,53]. Cardiomyocytes both express endothelin receptors and synthesize ET-1 [53]. The autocrine and paracrine activity of ET-1 plays a crucial role in the development of cardiomyocyte hypertrophy [54]. TNF-α mediates several adverse effects on cardiac function and structure, including negative inotropic effects due to disrupted calcium homeostasis, the upregulation of other inflammatory molecules, and enhanced endothelial–leukocyte interactions [42]. IL-1β, a key driver of cardiac inflammation, promotes cardiomyocyte apoptosis and the recruitment of inflammatory cells to the myocardium [50]. IL-6 similarly impairs cardiac function by inducing negative inotropic effects and promoting cardiac hypertrophy and fibrosis [50]. Elevated IL-6 levels have been associated with diuretic resistance and poor clinical outcomes, including mortality in patients with HF [42,55]. In acute HF, IL-6 levels measured 48–72 h after admission were independently predictive of 30-day mortality [56], and patients with cardiogenic shock exhibited an early surge in IL-6 levels [57]. These findings suggest that HF progression is driven, in part, by sustained chronic inflammation in addition to neurohormonal activation [58]. Long-term pharmacological modulation of chronic inflammation remains challenging due to the associated adverse effects. Therefore, the present study emphasizes the therapeutic promise of natural compounds, such as HS, as adjunctive agents in HF management. Given the limitations of conventional therapies, HS represents a potentially safer and more cost-effective alternative, particularly for use in resource-limited settings. As mentioned, several bioactive compounds have been isolated from HS extracts—β-sitosterol (HS-324), linoleic acid (HS-3253), syriacusin B (HS-3271), and tricetin 3′,5′-dimethyl ester (HS-363)—each warranting further investigation for their therapeutic relevance in HF (Figure 9). β-Sitosterol, a phytosterol, has demonstrated multiple biological effects, including stabilization of the phospholipid bilayers of cell membranes, improved glycemic control in adipose tissue in high-fat diet-fed type-2 diabetic rats, and protection against hypoxia/reoxygenation-induced H9c2 cardiomyocyte injury through oxidative stress reduction and mitochondrial function enhancement [59,60,61]. Linoleic acid, a dietary omega-6 polyunsaturated fatty acid, has been inversely associated with cardiovascular risk and systemic inflammation in both dietary and circulating biomarker studies [62]. Tricetin 3′,5′-dimethyl ester, also known as tricin, has been demonstrated to attenuate oxidative stress and suppress inflammatory mediator expression in vivo, particularly in murine models of myocardial injury induced by coronary artery ligation [63]. Tricin’s molecular mechanisms include inhibition of iNOS, COX-2, and NF-κB signaling, further supporting the relevance of plant-derived polyphenols in cardiovascular oxidative stress modulation [64]. Syriacusin B, a naphthalene compound isolated from the methanol extract of HS, has demonstrated inhibitory effects on lipid peroxidation, highlighting its potential antioxidant properties [65,66]. In addition, the antioxidant activities exhibited by various parts of HS highlight the plant’s phytochemical diversity and functional potential. In radical scavenging assays, the 70% ethanol extract showed that petals had the highest antioxidant activity (56.4% at 25 μg/mL), followed by leaves (45.3%), sprouts (31.4%), and roots (25.4%)—a trend that correlated with the respective polyphenol content in each tissue [5]. Further studies are warranted to evaluate the clinical efficacy, safety profile, and optimal dosing strategies for HS-based interventions in HF. Such efforts will lay the groundwork for integrating HS-derived compounds into evidence-based clinical practice.

4.4. Limitations of the Study and Future Directions

This study presents several limitations that should be considered. The in vitro design, while informative for mechanistic insight, limits direct clinical applicability. The absence of in vivo validation precludes assessment of pharmacokinetics, tissue distribution, and systemic effects. Thus, animal models and clinical trials are necessary to confirm the translational relevance of HS in HF treatment. The investigation primarily focused on antioxidant and anti-inflammatory effects in cardiomyocytes, without addressing other critical HF mechanisms, such as fibrosis, apoptosis, or neurohormonal activation or mitochondrial dysfunction. Furthermore, although we proposed involvement of NF-κB, Nrf2/HO-1, and ERK1/2 signaling, these pathways were not directly verified. The lack of in silico modeling or pathway-specific assays limits mechanistic conclusiveness, highlighting a key direction for future research. Moreover, inter-assay and inter-laboratory variability in extraction protocols, solvent composition, and assay conditions may influence the reproducibility of results. Standardization of extraction and quantification procedures will be necessary to ensure consistency and comparability across future investigations. Additionally, prior studies have shown that higher concentrations of HS extracts may reduce immune cell viability, raising concerns about dose-dependent cytotoxicity across different cell types [22]. Future dose–response and cell-type specificity studies are necessary to address this concern. Lastly, the long-term safety and efficacy of HS supplementation remain unknown. Robust clinical investigations are essential to establish its pharmacological profile and determine its potential as an adjunctive therapy in HF.

5. Conclusions

This study demonstrated the therapeutic potential of HS extracts in HF management, with significant reductions in ROS production and inflammatory mediators, indicative of cardioprotective properties. By elucidating the antioxidant and anti-inflammatory mechanisms of HS, our findings deepen the understanding of HF pathophysiology and suggest novel avenues for treatment. Given the limitations of current therapies in managing chronic inflammation and oxidative stress, HS offers promise as an adjunctive or alternative strategy. Future research should prioritize rigorous clinical trials to validate the efficacy and safety of HS, optimize its dosing and formulations, and explore its potential synergistic effects with established HF therapies, thereby advancing the field of cardiovascular therapeutics.

Author Contributions

Conceptualization, H.-H.C., T.-H.C. and L.-C.S.; Data curation, T.-H.C.; Formal analysis, T.-H.C., C.-C.C. and J.-C.L.; Funding acquisition, H.-H.C. and J.-C.L.; Investigation, T.-H.C. and J.-J.C.; Methodology, H.-H.C., T.-H.C. and J.-J.C.; Project administration, H.-H.C. and J.-C.L.; Resources, H.-H.C., T.-H.C., J.-C.L. and J.-J.C.; Supervision, T.-H.C., J.-C.L., J.-J.C. and L.-C.S.; Validation, T.-H.C., C.-C.C. and J.-J.C.; Visualization, T.-H.C. and L.-C.S.; Writing—original draft, H.-H.C., T.-H.C. and L.-C.S.; Writing—review & editing, H.-H.C., T.-H.C., C.-C.C., J.-C.L. and L.-C.S. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by Shin Kong Wu Ho-Su Memorial Hospital (grant number SKH-8302-101-DR-05). The funding source had no role in the design, conduct, or analyses of the study or the decision to submit the manuscript for publication.

Informed Consent Statement

Not applicable.

Data Availability Statement

The authors confirm that the data supporting the findings of this study are available within the article.

Acknowledgments

The author gratefully acknowledges Wei-Ping Chiang for kindly providing images from her graduate thesis, which contributed to the preparation of three figures in this study.

Conflicts of Interest

The authors declare no conflicts of interest.

Abbreviations

Ang II: angiotensin II; BNP: brain natriuretic peptide; CCL20: C-C chemokine ligand 20; DCFH-DA: 2′,7′-dichlorofluorescin diacetate; ELISA: enzyme-linked immunosorbent assay; ET-1: endothelin-1; HF: heart failure; HPLC: high-performance liquid chromatography; HS: Hibiscus syriacus L.; HS(-Bu): butanol; HS(-EA): ethyl acetate; HS(-EtOH): ethanol; HS(-Hex): hexane; HS(-H2O): water; IL-1β: interleukin-1β; IL-6: interleukin-6; LPS: lipopolysaccharide; RAAS: renin–angiotensin–aldosterone system; ROS: reactive oxygen species; TNF-α: tumor necrosis factor-alpha.

References

  1. Shah, K.S.; Xu, H.; Matsouaka, R.A.; Bhatt, D.L.; Heidenreich, P.A.; Hernandez, A.F.; Devore, A.D.; Yancy, C.W.; Fonarow, G.C. Heart Failure With Preserved, Borderline, and Reduced Ejection Fraction: 5-Year Outcomes. J. Am. Coll. Cardiol. 2017, 70, 2476–2486. [Google Scholar] [CrossRef]
  2. Savarese, G.; Becher, P.M.; Lund, L.H.; Seferovic, P.; Rosano, G.M.C.; Coats, A.J.S. Global burden of heart failure: A comprehensive and updated review of epidemiology. Cardiovasc. Res. 2023, 118, 3272–3287. [Google Scholar] [CrossRef] [PubMed]
  3. Choi, Y.; Park, Y.H.; Yang, C.; Kim, D.H.; Lee, K.W.; Lee, M.Y. Protocol for a randomized controlled trial evaluating the effect of Hibiscus syriacus L. flower extract on sleep quality. Front. Nutr. 2023, 10, 1169193. [Google Scholar] [CrossRef]
  4. Kim, Y.R.; Lee, S.Y.; Lee, S.M.; Shim, I.; Lee, M.Y. Effect of Hibiscus syriacus Linnaeus extract and its active constituent, saponarin, in animal models of stress-induced sleep disturbances and pentobarbital-induced sleep. Biomed. Pharmacother. 2022, 146, 112301. [Google Scholar] [CrossRef] [PubMed]
  5. Park, Y.; Kwon, S.H.; Jang, Y.L.; Lee, D.H.; Yang, S.O.; Eo, H.J.; Park, G.H.; Kwon, H.Y. Nutritional composition and phytochemical screening in different parts of Hibiscus syriacus L. Food Sci. Nutr. 2022, 10, 3034–3042. [Google Scholar] [CrossRef]
  6. Karunarathne, W.; Molagoda, I.M.N.; Lee, K.T.; Choi, Y.H.; Yu, S.M.; Kang, C.H.; Kim, G.Y. Protective Effect of Anthocyanin-Enriched Polyphenols from Hibiscus syriacus L. (Malvaceae) against Ultraviolet B-Induced Damage. Antioxidants 2021, 10, 584. [Google Scholar] [CrossRef]
  7. Cook, C.; Cole, G.; Asaria, P.; Jabbour, R.; Francis, D.P. The annual global economic burden of heart failure. Int. J. Cardiol. 2014, 171, 368–376. [Google Scholar] [CrossRef]
  8. Ferrario, C.M. Cardiac remodelling and RAS inhibition. Ther. Adv. Cardiovasc. Dis. 2016, 10, 162–171. [Google Scholar] [CrossRef]
  9. Clark, A.M.; Wiens, K.S.; Banner, D.; Kryworuchko, J.; Thirsk, L.; McLean, L.; Currie, K. A systematic review of the main mechanisms of heart failure disease management interventions. Heart 2016, 102, 707–711. [Google Scholar] [CrossRef]
  10. Mann, D.L.; Felker, G.M. Mechanisms and Models in Heart Failure: A Translational Approach. Circ. Res. 2021, 128, 1435–1450. [Google Scholar] [CrossRef] [PubMed]
  11. Chen, X.J.; Liu, S.Y.; Li, S.M.; Feng, J.K.; Hu, Y.; Cheng, X.Z.; Hou, C.Z.; Xu, Y.; Hu, M.; Feng, L.; et al. The recent advance and prospect of natural source compounds for the treatment of heart failure. Heliyon 2024, 10, e27110. [Google Scholar] [CrossRef] [PubMed]
  12. Chen, J.; Wei, X.; Zhang, Q.; Wu, Y.; Xia, G.; Xia, H.; Wang, L.; Shang, H.; Lin, S. The traditional Chinese medicines treat chronic heart failure and their main bioactive constituents and mechanisms. Acta Pharm. Sin. B 2023, 13, 1919–1955. [Google Scholar] [CrossRef]
  13. Ellis, L.R.; Zulfiqar, S.; Holmes, M.; Marshall, L.; Dye, L.; Boesch, C. A systematic review and meta-analysis of the effects of Hibiscus sabdariffa on blood pressure and cardiometabolic markers. Nutr. Rev. 2022, 80, 1723–1737. [Google Scholar] [CrossRef]
  14. Kaushik, N.; Oh, H.; Lim, Y.; Kumar Kaushik, N.; Nguyen, L.N.; Choi, E.H.; Kim, J.H. Screening of Hibiscus and Cinnamomum Plants and Identification of Major Phytometabolites in Potential Plant Extracts Responsible for Apoptosis Induction in Skin Melanoma and Lung Adenocarcinoma Cells. Front. Bioeng. Biotechnol. 2021, 9, 779393. [Google Scholar] [CrossRef] [PubMed]
  15. Xu, X.Y.; Choi, H.S.; Park, S.Y.; Kim, J.K.; Seo, K.H.; Kim, H.; Kim, Y.J. Hibiscus syriacus L. cultivated in callus culture exerts cytotoxicity in colorectal cancer via Notch signaling-mediated cholesterol biosynthesis suppression. Phytomedicine 2022, 95, 153870. [Google Scholar] [CrossRef]
  16. Balkrishna, A.; Mishra, S.; Singh, A.; Srivastava, D.; Singh, S.; Arya, V. Hibiscus syriacus L.: A Critical Review of Medicinal Utility & Phytopharmacology with Mechanistic Approach. J. Phytopharm. 2022, 11, 204–210. [Google Scholar] [CrossRef]
  17. Ziyanok-Demirtas, S. A Holistic In Silico and In Vivo Approach to Exploring the Antidiabetic, Antioxidant, and Hepatoprotective Properties of Rose of Sharon. Life 2024, 14, 686. [Google Scholar] [CrossRef]
  18. Karunarathne, W.; Molagoda, I.M.N.; Lee, K.T.; Choi, Y.H.; Jin, C.Y.; Kim, G.Y. Anthocyanin-enriched polyphenols from Hibiscus syriacus L. (Malvaceae) exert anti-osteoporosis effects by inhibiting GSK-3beta and subsequently activating beta-catenin. Phytomedicine 2021, 91, 153721. [Google Scholar] [CrossRef]
  19. Xu, X.Y.; Tran, T.H.M.; Perumalsamy, H.; Sanjeevram, D.; Kim, Y.J. Biosynthetic gold nanoparticles of Hibiscus syriacus L. callus potentiates anti-inflammation efficacy via an autophagy-dependent mechanism. Mater. Sci. Eng. C Mater. Biol. Appl. 2021, 124, 112035. [Google Scholar] [CrossRef]
  20. Karunarathne, W.; Molagoda, I.M.N.; Park, S.R.; Kim, J.W.; Lee, O.K.; Kwon, H.Y.; Oren, M.; Choi, Y.H.; Ryu, H.W.; Oh, S.R.; et al. Anthocyanins from Hibiscus syriacus L. Inhibit Melanogenesis by Activating the ERK Signaling Pathway. Biomolecules 2019, 9, 645. [Google Scholar] [CrossRef] [PubMed]
  21. Molagoda, I.M.N.; Lee, K.T.; Choi, Y.H.; Kim, G.Y. Anthocyanins from Hibiscus syriacus L. Inhibit Oxidative Stress-Mediated Apoptosis by Activating the Nrf2/HO-1 Signaling Pathway. Antioxidants 2020, 9, 42. [Google Scholar] [CrossRef]
  22. Karunarathne, W.; Lee, K.T.; Choi, Y.H.; Jin, C.Y.; Kim, G.Y. Anthocyanins isolated from Hibiscus syriacus L. attenuate lipopolysaccharide-induced inflammation and endotoxic shock by inhibiting the TLR4/MD2-mediated NF-kappaB signaling pathway. Phytomedicine 2020, 76, 153237. [Google Scholar] [CrossRef]
  23. Molagoda, I.M.N.; Lee, K.T.; Choi, Y.H.; Jayasingha, J.; Kim, G.Y. Anthocyanins from Hibiscus syriacus L. Inhibit NLRP3 Inflammasome in BV2 Microglia Cells by Alleviating NF-kappaB- and ER Stress-Induced Ca2+ Accumulation and Mitochondrial ROS Production. Oxidative Med. Cell. Longev. 2021, 2021, 1246491. [Google Scholar] [CrossRef]
  24. Yoon, S.W.; Lee, K.P.; Kim, D.Y.; Hwang, D.I.; Won, K.J.; Lee, D.W.; Lee, H.M. Effect of Absolute From Hibiscus syriacus L. Flower on Wound Healing in Keratinocytes. Pharmacogn. Mag. 2017, 13, 85–89. Available online: https://pubmed.ncbi.nlm.nih.gov/28216888/ (accessed on 27 June 2025).
  25. Sanchez-Hernandez, E.; Buzon-Duran, L.; Lorenzo-Vidal, B.; Martin-Gil, J.; Martin-Ramos, P. Physicochemical Characterization and Antimicrobial Activity against Erwinia amylovora, Erwinia vitivora, and Diplodia seriata of a Light Purple Hibiscus syriacus L. Cultivar. Plants 2021, 10, 1876. [Google Scholar] [CrossRef] [PubMed]
  26. Kim, Y.H.; Im, A.R.; Park, B.K.; Paek, S.H.; Choi, G.; Kim, Y.R.; Whang, W.K.; Lee, K.H.; Oh, S.E.; Lee, M.Y. Antidepressant-Like and Neuroprotective Effects of Ethanol Extract from the Root Bark of Hibiscus syriacus L. BioMed Res. Int. 2018, 2018, 7383869. [Google Scholar] [CrossRef]
  27. Shi, L.S.; Wu, C.H.; Yang, T.C.; Yao, C.W.; Lin, H.C.; Chang, W.L. Cytotoxic effect of triterpenoids from the root bark of Hibiscus syriacus. Fitoterapia 2014, 97, 184–191. [Google Scholar] [CrossRef]
  28. Yang, J.E.; Ngo, H.T.T.; Hwang, E.; Seo, S.A.; Park, S.W.; Yi, T.H. Dietary enzyme-treated Hibiscus syriacus L. protects skin against chronic UVB-induced photoaging via enhancement of skin hydration and collagen synthesis. Arch. Biochem. Biophys. 2019, 662, 190–200. [Google Scholar] [CrossRef] [PubMed]
  29. Ali, S.S.; Mohamed, S.F.A.; Rozalei, N.H.; Boon, Y.W.; Zainalabidin, S. Anti-fibrotic Actions of Roselle Extract in Rat Model of Myocardial Infarction. Cardiovasc. Toxicol. 2019, 19, 72–81. [Google Scholar] [CrossRef]
  30. Hosseini, A.; Bakhtiari, E.; Mousavi, S.H. Protective Effect of Hibiscus Sabdariffa on Doxorubicin-induced Cytotoxicity in H9c2 Cardiomyoblast Cells. Iran. J. Pharm. Res. 2017, 16, 708–713. [Google Scholar] [PubMed]
  31. Nadar, S.K.; Shaikh, M.M. Biomarkers in Routine Heart Failure Clinical Care. Card. Fail. Rev. 2019, 5, 50–56. [Google Scholar] [CrossRef]
  32. Szabo, T.M.; Frigy, A.; Nagy, E.E. Targeting Mediators of Inflammation in Heart Failure: A Short Synthesis of Experimental and Clinical Results. Int. J. Mol. Sci. 2021, 22, 13053. [Google Scholar] [CrossRef]
  33. Mongirdiene, A.; Skrodenis, L.; Varoneckaite, L.; Mierkyte, G.; Gerulis, J. Reactive Oxygen Species Induced Pathways in Heart Failure Pathogenesis and Potential Therapeutic Strategies. Biomedicines 2022, 10, 602. [Google Scholar] [CrossRef] [PubMed]
  34. Kimes, B.W.; Brandt, B.L. Properties of a clonal muscle cell line from rat heart. Exp. Cell Res. 1976, 98, 367–381. [Google Scholar] [CrossRef]
  35. Shih, N.-L.; Cheng, T.-H.; Loh, S.-H.; Cheng, P.-Y.; Wang, D.L.; Chen, Y.-S.; Liu, S.-H.; Liew, C.-C.; Chen, J.-J. Reactive Oxygen Species Modulate Angiotensin II-Induced β-Myosin Heavy Chain Gene Expression via Ras/Raf/Extracellular Signal-Regulated Kinase Pathway in Neonatal Rat Cardiomyocytes. Biochem. Biophys. Res. Commun. 2001, 283, 143–148. [Google Scholar] [CrossRef]
  36. Cheng, T.H.; Liu, J.C.; Lin, H.; Shih, N.L.; Chen, Y.L.; Huang, M.T.; Chan, P.; Cheng, C.F.; Chen, J.J. Inhibitory effect of resveratrol on angiotensin II-induced cardiomyocyte hypertrophy. Naunyn Schmiedebergs Arch. Pharmacol. 2004, 369, 239–244. [Google Scholar] [CrossRef]
  37. Liu, J.C.; Chen, C.H.; Chen, J.J.; Cheng, T.H. Urotensin II induces rat cardiomyocyte hypertrophy via the transient oxidization of Src homology 2-containing tyrosine phosphatase and transactivation of epidermal growth factor receptor. Mol. Pharmacol. 2009, 76, 1186–1195. [Google Scholar] [CrossRef]
  38. Tsai, Y.T.; Sung, L.C.; Haw, W.R.; Chen, C.C.; Huang, S.F.; Liu, J.C.; Cheng, T.H.; Chen, P.Y.; Loh, S.H.; Tsai, C.S. Cafestol, a coffee diterpene, inhibits urotensin II-induced interleukin-8 expression in human umbilical vein endothelial cells. Eur. J. Pharmacol. 2018, 820, 106–112. [Google Scholar] [CrossRef] [PubMed]
  39. Chiang, W.-P. A Chinese Herbal Medicine, Hibiscus syriacus Extracts, Exhibits Anti-Oxidative, Anti-Inflammatory and Anti-Atherosclerotic Activities. Master’s Thesis, China Medical University, Taichung, Taiwan, 2013. Available online: https://hdl.handle.net/11296/4t9mfj (accessed on 25 July 2025).
  40. Weissman, D.; Maack, C. Redox signaling in heart failure and therapeutic implications. Free Radic. Biol. Med. 2021, 171, 345–364. [Google Scholar] [CrossRef] [PubMed]
  41. Murphy, S.P.; Kakkar, R.; McCarthy, C.P.; Januzzi, J.L., Jr. Inflammation in Heart Failure: JACC State-of-the-Art Review. J. Am. Coll. Cardiol. 2020, 75, 1324–1340. [Google Scholar] [CrossRef]
  42. Reina-Couto, M.; Pereira-Terra, P.; Quelhas-Santos, J.; Silva-Pereira, C.; Albino-Teixeira, A.; Sousa, T. Inflammation in Human Heart Failure: Major Mediators and Therapeutic Targets. Front. Physiol. 2021, 12, 746494. [Google Scholar] [CrossRef]
  43. Boulet, J.; Sridhar, V.S.; Bouabdallaoui, N.; Tardif, J.C.; White, M. Inflammation in heart failure: Pathophysiology and therapeutic strategies. Inflamm. Res. 2024, 73, 709–723. [Google Scholar] [CrossRef]
  44. Yang, C.M.; Yang, C.C.; Hsu, W.H.; Hsiao, L.D.; Tseng, H.C.; Shih, Y.F. Tumor Necrosis Factor-alpha-Induced C-C Motif Chemokine Ligand 20 Expression through TNF Receptor 1-Dependent Activation of EGFR/p38 MAPK and JNK1/2/FoxO1 or the NF-kappaB Pathway in Human Cardiac Fibroblasts. Int. J. Mol. Sci. 2022, 23, 9086. [Google Scholar] [CrossRef]
  45. Schutyser, E.; Struyf, S.; Van Damme, J. The CC chemokine CCL20 and its receptor CCR6. Cytokine Growth Factor. Rev. 2003, 14, 409–426. [Google Scholar] [CrossRef] [PubMed]
  46. Safa, A.; Rashidinejad, H.R.; Khalili, M.; Dabiri, S.; Nemati, M.; Mohammadi, M.M.; Jafarzadeh, A. Higher circulating levels of chemokines CXCL10, CCL20 and CCL22 in patients with ischemic heart disease. Cytokine 2016, 83, 147–157. [Google Scholar] [CrossRef] [PubMed]
  47. Chen, G.; Pan, S.Q.; Shen, C.; Pan, S.F.; Zhang, X.M.; He, Q.Y. Puerarin inhibits angiotensin II-induced cardiac hypertrophy via the redox-sensitive ERK1/2, p38 and NF-kappaB pathways. Acta Pharmacol. Sin. 2014, 35, 463–475. [Google Scholar] [CrossRef]
  48. Sepúlveda-Fragoso, V.; Alexandre-Santos, B.; Salles, A.C.P.; Proença, A.B.; de Paula Alves, A.P.; Vázquez-Carrera, M.; Nóbrega, A.C.L.; Frantz, E.D.C.; Magliano, D.C. Crosstalk between the renin-angiotensin system and the endoplasmic reticulum stress in the cardiovascular system: Lessons learned so far. Life Sci. 2021, 284, 119919. [Google Scholar] [CrossRef]
  49. Chen, Y.; Zeng, M.; Zhang, Y.; Guo, H.; Ding, W.; Sun, T. Nlrp3 Deficiency Alleviates Angiotensin II-Induced Cardiomyopathy by Inhibiting Mitochondrial Dysfunction. Oxidative Med. Cell. Longev. 2021, 2021, 6679100. [Google Scholar] [CrossRef]
  50. Hanna, A.; Frangogiannis, N.G. Inflammatory Cytokines and Chemokines as Therapeutic Targets in Heart Failure. Cardiovasc. Drugs Ther. 2020, 34, 849–863. [Google Scholar] [CrossRef]
  51. Lin, C.F.; Su, C.J.; Liu, J.H.; Chen, S.T.; Huang, H.L.; Pan, S.L. Potential Effects of CXCL9 and CCL20 on Cardiac Fibrosis in Patients with Myocardial Infarction and Isoproterenol-Treated Rats. J. Clin. Med. 2019, 8, 659. [Google Scholar] [CrossRef]
  52. Yeager, M.E.; Belchenko, D.D.; Nguyen, C.M.; Colvin, K.L.; Ivy, D.D.; Stenmark, K.R. Endothelin-1, the unfolded protein response, and persistent inflammation: Role of pulmonary artery smooth muscle cells. Am. J. Respir. Cell Mol. Biol. 2012, 46, 14–22. [Google Scholar] [CrossRef]
  53. Kowalczyk, A.; Kleniewska, P.; Kolodziejczyk, M.; Skibska, B.; Goraca, A. The role of endothelin-1 and endothelin receptor antagonists in inflammatory response and sepsis. Arch. Immunol. Ther. Exp. (Warsz.) 2015, 63, 41–52. [Google Scholar] [CrossRef] [PubMed]
  54. Drawnel, F.M.; Archer, C.R.; Roderick, H.L. The role of the paracrine/autocrine mediator endothelin-1 in regulation of cardiac contractility and growth. Br. J. Pharmacol. 2013, 168, 296–317. [Google Scholar] [CrossRef] [PubMed]
  55. Maeda, K.; Tsutamoto, T.; Wada, A.; Mabuchi, N.; Hayashi, M.; Tsutsui, T.; Ohnishi, M.; Sawaki, M.; Fujii, M.; Matsumoto, T.; et al. High levels of plasma brain natriuretic peptide and interleukin-6 after optimized treatment for heart failure are independent risk factors for morbidity and mortality in patients with congestive heart failure. J. Am. Coll. Cardiol. 2000, 36, 1587–1593. [Google Scholar] [CrossRef] [PubMed]
  56. Perez, A.L.; Grodin, J.L.; Chaikijurajai, T.; Wu, Y.; Hernandez, A.F.; Butler, J.; Metra, M.; Felker, G.M.; Voors, A.A.; McMurray, J.J.; et al. Interleukin-6 and Outcomes in Acute Heart Failure: An ASCEND-HF Substudy. J. Card. Fail. 2021, 27, 670–676. [Google Scholar] [CrossRef]
  57. Cuinet, J.; Garbagnati, A.; Rusca, M.; Yerly, P.; Schneider, A.G.; Kirsch, M.; Liaudet, L. Cardiogenic shock elicits acute inflammation, delayed eosinophilia, and depletion of immune cells in most severe cases. Sci. Rep. 2020, 10, 7639. [Google Scholar] [CrossRef]
  58. Seta, Y.; Shan, K.; Bozkurt, B.; Oral, H.; Mann, D.L. Basic mechanisms in heart failure: The cytokine hypothesis. J. Card. Fail. 1996, 2, 243–249. [Google Scholar] [CrossRef]
  59. Lin, F.; Xu, L.; Huang, M.; Deng, B.; Zhang, W.; Zeng, Z.; Yinzhi, S. beta-Sitosterol Protects against Myocardial Ischemia/Reperfusion Injury via Targeting PPARgamma/NF-kappaB Signalling. Evid. Based Complement. Altern. Med. 2020, 2020, 2679409. [Google Scholar] [CrossRef]
  60. Khan, Z.; Nath, N.; Rauf, A.; Emran, T.B.; Mitra, S.; Islam, F.; Chandran, D.; Barua, J.; Khandaker, M.U.; Idris, A.M.; et al. Multifunctional roles and pharmacological potential of beta-sitosterol: Emerging evidence toward clinical applications. Chem. Biol. Interact. 2022, 365, 110117. [Google Scholar] [CrossRef]
  61. Babu, S.; Krishnan, M.; Rajagopal, P.; Periyasamy, V.; Veeraraghavan, V.; Govindan, R.; Jayaraman, S. Beta-sitosterol attenuates insulin resistance in adipose tissue via IRS-1/Akt mediated insulin signaling in high fat diet and sucrose induced type-2 diabetic rats. Eur. J. Pharmacol. 2020, 873, 173004. [Google Scholar] [CrossRef]
  62. Harris, W.S.; Mozaffarian, D.; Rimm, E.; Kris-Etherton, P.; Rudel, L.L.; Appel, L.J.; Engler, M.M.; Engler, M.B.; Sacks, F. Omega-6 fatty acids and risk for cardiovascular disease: A science advisory from the American Heart Association Nutrition Subcommittee of the Council on Nutrition, Physical Activity, and Metabolism; Council on Cardiovascular Nursing; and Council on Epidemiology and Prevention. Circulation 2009, 119, 902–907. [Google Scholar] [CrossRef]
  63. Feilong, S.; Xue, M.; Yu, W.; Fang, L. Investigating the role and mechanisms of tricin in ischemia-reperfusion-induced myocardial injury in LDLr -/- MICE. Pak. J. Pharm. Sci. 2023, 36, 1045–1051. [Google Scholar]
  64. Shalini, V.; Bhaskar, S.; Kumar, K.S.; Mohanlal, S.; Jayalekshmy, A.; Helen, A. Molecular mechanisms of anti-inflammatory action of the flavonoid, tricin from Njavara rice (Oryza sativa L.) in human peripheral blood mononuclear cells: Possible role in the inflammatory signaling. Int. Immunopharmacol. 2012, 14, 32–38. [Google Scholar] [CrossRef] [PubMed]
  65. Yoo, I.D.; Yun, B.S.; Lee, I.K.; Ryoo, I.J.; Choung, D.H.; Han, K.H. Three naphthalenes from root bark of Hibiscus syriacus. Phytochemistry 1998, 47, 799–802. [Google Scholar] [CrossRef] [PubMed]
  66. Ryoo, I.-J.; Moon, E.-Y.; Kim, Y.-H.; Lee, I.-S.; Choo, S.-J.; Bae, K.-H.; Yoo, I.-D. Anti-Skin Aging Effect of Syriacusins from Hibiscus syriacus on Ultraviolet-Irradiated Human Dermal Fibroblast Cells. Biomol. Ther. 2010, 18, 300–307. [Google Scholar] [CrossRef]
Life 15 01229 g001
Figure 1. Photographs of Hibiscus syriacus L. This figure displays the distinctive features of Hibiscus syriacus L. (A) Complete morphology of the plant, including the stem, flowers, and leaves. (B) Close-up view of the plant’s characteristic flowers.
Figure 1. Photographs of Hibiscus syriacus L. This figure displays the distinctive features of Hibiscus syriacus L. (A) Complete morphology of the plant, including the stem, flowers, and leaves. (B) Close-up view of the plant’s characteristic flowers.
Life 15 01229 g001
Life 15 01229 g002
Figure 2. Preparation and Sequential Fractionation of Crude Hibiscus syriacus L. Extracts. This figure illustrates the stepwise extraction and fractionation protocol used to isolate bioactive constituents from Hibiscus syriacus L. (HS) extracts. Initially, the plant material was extracted three times with 95% ethanol, chosen for its broad-spectrum solubility and ability to recover both polar and non-polar compounds, including flavonoids, sterols, and anthocyanins [5,26]. The combined ethanol extracts were concentrated under reduced pressure to yield the crude ethanol extract (HS-EtOH). To enrich specific phytochemical classes, HS-EtOH was sequentially partitioned using solvents of increasing polarity—hexane (HS-Hex), ethyl acetate (HS-EA), n-butanol (HS-BuOH), and water (HS-H2O)—based on solubility gradients [18,21]. This polarity-guided fractionation enabled the separation of structurally diverse compounds, facilitating targeted analysis of antioxidant, anti-inflammatory, and cytotoxic activities reported in previous studies [15,24,27]. Adapted from the master’s thesis of Wei-Ping Chiang [39]. The resulting fractions were used for phytochemical profiling and bioactivity assays.
Figure 2. Preparation and Sequential Fractionation of Crude Hibiscus syriacus L. Extracts. This figure illustrates the stepwise extraction and fractionation protocol used to isolate bioactive constituents from Hibiscus syriacus L. (HS) extracts. Initially, the plant material was extracted three times with 95% ethanol, chosen for its broad-spectrum solubility and ability to recover both polar and non-polar compounds, including flavonoids, sterols, and anthocyanins [5,26]. The combined ethanol extracts were concentrated under reduced pressure to yield the crude ethanol extract (HS-EtOH). To enrich specific phytochemical classes, HS-EtOH was sequentially partitioned using solvents of increasing polarity—hexane (HS-Hex), ethyl acetate (HS-EA), n-butanol (HS-BuOH), and water (HS-H2O)—based on solubility gradients [18,21]. This polarity-guided fractionation enabled the separation of structurally diverse compounds, facilitating targeted analysis of antioxidant, anti-inflammatory, and cytotoxic activities reported in previous studies [15,24,27]. Adapted from the master’s thesis of Wei-Ping Chiang [39]. The resulting fractions were used for phytochemical profiling and bioactivity assays.
Life 15 01229 g002
Life 15 01229 g003
Figure 3. High-Performance Liquid Chromatography (HPLC) and Nuclear Magnetic Resonance (NMR) Analysis. This figure presents the analytical methods used to identify and characterize bioactive compounds extracted from HS. HPLC was used to separate and quantify phytochemical constituents, enabling the identification of specific compounds such as Syriacusin B (HS-3271), linoleic acid (HS-3253) and 2-linoleodistearin (HS-3295). NMR spectroscopy was subsequently used to determine the molecular structures and functional groups of these isolates, confirming the presence of key bioactive compounds, including syriacusin B and tricetin 3′,5′-dimethyl ester. Adapted from the master’s thesis of Wei-Ping Chiang [39]. These analyses verified compound purity and chemical identity, providing molecular validation for downstream biological testing.
Figure 3. High-Performance Liquid Chromatography (HPLC) and Nuclear Magnetic Resonance (NMR) Analysis. This figure presents the analytical methods used to identify and characterize bioactive compounds extracted from HS. HPLC was used to separate and quantify phytochemical constituents, enabling the identification of specific compounds such as Syriacusin B (HS-3271), linoleic acid (HS-3253) and 2-linoleodistearin (HS-3295). NMR spectroscopy was subsequently used to determine the molecular structures and functional groups of these isolates, confirming the presence of key bioactive compounds, including syriacusin B and tricetin 3′,5′-dimethyl ester. Adapted from the master’s thesis of Wei-Ping Chiang [39]. These analyses verified compound purity and chemical identity, providing molecular validation for downstream biological testing.
Life 15 01229 g003
Life 15 01229 g004
Figure 4. Cytotoxicity of HS Extracts Against H9c2 Cells. Cell viability was evaluated using the Cell Counting Kit-8 following exposure to varying concentrations of HS extracts: HS-Hex (panel A), HS-EA (panel B), HS-BuOH (panel C), and HS-H2O (panel D). Untreated H9c2 cells served as the control, with viability normalized to 100%. The results are presented as mean ± standard error of the mean (SEM; n = 6). Statistically significant differences were observed for comparisons with untreated controls (* p < 0.05). This experiment was conducted to determine non-toxic concentration ranges for use in subsequent mechanistic assays.
Figure 4. Cytotoxicity of HS Extracts Against H9c2 Cells. Cell viability was evaluated using the Cell Counting Kit-8 following exposure to varying concentrations of HS extracts: HS-Hex (panel A), HS-EA (panel B), HS-BuOH (panel C), and HS-H2O (panel D). Untreated H9c2 cells served as the control, with viability normalized to 100%. The results are presented as mean ± standard error of the mean (SEM; n = 6). Statistically significant differences were observed for comparisons with untreated controls (* p < 0.05). This experiment was conducted to determine non-toxic concentration ranges for use in subsequent mechanistic assays.
Life 15 01229 g004
Life 15 01229 g005
Figure 5. Effects of HS Extracts on Ang II-Stimulated ROS Production in H9c2 Rat Cardiomyocytes. H9c2 cells were pretreated with vehicle control or varying concentrations of HS extracts (HS-Hex, HS-EA, and HS-H2O; 10, 30, and 50 μg/mL) for 24 h, followed by cotreatment with Ang II (100 nM) for 2 h. ROS production was measured using DCF-based fluorescence assays, with fluorescence intensities in vehicle-treated control cells normalized to 100%. The results are expressed as mean ± SEM (n = 5). Statistical analysis revealed significant differences: * p < 0.05 compared with untreated controls; # p < 0.05 compared with cells treated with Ang II alone. This assay assessed the antioxidant potential of HS extracts in an oxidative stress model relevant to HF.
Figure 5. Effects of HS Extracts on Ang II-Stimulated ROS Production in H9c2 Rat Cardiomyocytes. H9c2 cells were pretreated with vehicle control or varying concentrations of HS extracts (HS-Hex, HS-EA, and HS-H2O; 10, 30, and 50 μg/mL) for 24 h, followed by cotreatment with Ang II (100 nM) for 2 h. ROS production was measured using DCF-based fluorescence assays, with fluorescence intensities in vehicle-treated control cells normalized to 100%. The results are expressed as mean ± SEM (n = 5). Statistical analysis revealed significant differences: * p < 0.05 compared with untreated controls; # p < 0.05 compared with cells treated with Ang II alone. This assay assessed the antioxidant potential of HS extracts in an oxidative stress model relevant to HF.
Life 15 01229 g005
Life 15 01229 g006aLife 15 01229 g006b
Figure 6. (A). Effects of HS Extracts on Ang II-Stimulated Protein Synthesis in H9c2 Rat Cardiomyocytes. H9c2 rat cardiomyocytes were pretreated with either a vehicle control or various concentrations of HS extracts (HS-Hex, HS-EA, and HS-H2O; 10, 30, and 50 μg/mL) for 24 h, followed by cotreatment with Ang II (100 nM) for an additional 24 h. The results are presented as mean ± SEM, based on triplicate determinations across each experiment (n = 5). Significant differences were observed: * p < 0.05 compared with vehicle control; # p < 0.05 compared with Ang II treatment alone. This experiment evaluated the potential of HS extracts to prevent cardiomyocyte hypertrophy, a hallmark of HF. (B). Effects of Pure Compounds on Ang II-Stimulated Protein Synthesis in H9c2 Rat Cardiomyocytes. H9c2 rat cardiomyocytes were pretreated with either a vehicle control or varying concentrations of pure compounds extracted from HS—HS-324 (a), HS-3253 (b), HS-363 (c), and HS-3271 (d)—for 24 h, followed by cotreatment with Ang II (100 nM) for an additional 24 h. The results are presented as the mean ± SEM for each experiment (n = 5), with triplicate determinations. Significant differences were noted: * p < 0.05 compared with vehicle control; # p < 0.05 compared with Ang II treatment alone. This figure confirms that isolated bioactive compounds from HS also attenuate Ang II-induced hypertrophic signaling.
Figure 6. (A). Effects of HS Extracts on Ang II-Stimulated Protein Synthesis in H9c2 Rat Cardiomyocytes. H9c2 rat cardiomyocytes were pretreated with either a vehicle control or various concentrations of HS extracts (HS-Hex, HS-EA, and HS-H2O; 10, 30, and 50 μg/mL) for 24 h, followed by cotreatment with Ang II (100 nM) for an additional 24 h. The results are presented as mean ± SEM, based on triplicate determinations across each experiment (n = 5). Significant differences were observed: * p < 0.05 compared with vehicle control; # p < 0.05 compared with Ang II treatment alone. This experiment evaluated the potential of HS extracts to prevent cardiomyocyte hypertrophy, a hallmark of HF. (B). Effects of Pure Compounds on Ang II-Stimulated Protein Synthesis in H9c2 Rat Cardiomyocytes. H9c2 rat cardiomyocytes were pretreated with either a vehicle control or varying concentrations of pure compounds extracted from HS—HS-324 (a), HS-3253 (b), HS-363 (c), and HS-3271 (d)—for 24 h, followed by cotreatment with Ang II (100 nM) for an additional 24 h. The results are presented as the mean ± SEM for each experiment (n = 5), with triplicate determinations. Significant differences were noted: * p < 0.05 compared with vehicle control; # p < 0.05 compared with Ang II treatment alone. This figure confirms that isolated bioactive compounds from HS also attenuate Ang II-induced hypertrophic signaling.
Life 15 01229 g006aLife 15 01229 g006b
Life 15 01229 g007
Figure 7. Effects of HS Extracts on Ang II-Stimulated Inflammatory Cytokines and Chemokines in H9c2 Rat Cardiomyocytes. The expression levels of inflammatory biomarkers, including interleukin IL-1β (IL-1β; panel A), interleukin 6 (IL-6; panel B), tumor necrosis factor-α (TNF-α; panel C), and CC chemokine ligand 20 (CCL20; panel D), were assessed. H9c2 cells were pretreated with a vehicle control or various HS extracts (HS-Hex, HS-EA, and HS-H2O; 50 μg/mL) for 24 h, followed by cotreatment with Ang II (100 nM) for an additional 24 h. The results are presented as mean ± SEM (n = 5). Statistical analysis revealed significant differences: * p < 0.05 compared with untreated controls; # p < 0.05 compared with cells treated with Ang II alone. This experiment demonstrated the anti-inflammatory activity of HS extracts in an in vitro HF model.
Figure 7. Effects of HS Extracts on Ang II-Stimulated Inflammatory Cytokines and Chemokines in H9c2 Rat Cardiomyocytes. The expression levels of inflammatory biomarkers, including interleukin IL-1β (IL-1β; panel A), interleukin 6 (IL-6; panel B), tumor necrosis factor-α (TNF-α; panel C), and CC chemokine ligand 20 (CCL20; panel D), were assessed. H9c2 cells were pretreated with a vehicle control or various HS extracts (HS-Hex, HS-EA, and HS-H2O; 50 μg/mL) for 24 h, followed by cotreatment with Ang II (100 nM) for an additional 24 h. The results are presented as mean ± SEM (n = 5). Statistical analysis revealed significant differences: * p < 0.05 compared with untreated controls; # p < 0.05 compared with cells treated with Ang II alone. This experiment demonstrated the anti-inflammatory activity of HS extracts in an in vitro HF model.
Life 15 01229 g007
Life 15 01229 g008
Figure 8. Effects of HS Extracts on Ang II-Stimulated Heart Failure Biomarkers in H9c2 Rat Cardiomyocytes. The levels of heart failure risk biomarkers, including brain natriuretic peptide (BNP; panel A) and endothelin-1 (ET-1; panel B), were analyzed. H9c2 cells were pretreated with vehicle or various HS extracts (HS-Hex, HS-EA, and HS-H2O; 50 μg/mL) for 24 h, followed by cotreatment with Ang II (100 nM) for an additional 24 h. The results are presented as mean ± SEM (n = 6). Statistical analysis revealed significant differences: * p < 0.05 compared with untreated controls; # p < 0.05 compared with cells treated with Ang II alone. These data support the potential of HS extracts in modulating neurohormonal markers associated with HF progression.
Figure 8. Effects of HS Extracts on Ang II-Stimulated Heart Failure Biomarkers in H9c2 Rat Cardiomyocytes. The levels of heart failure risk biomarkers, including brain natriuretic peptide (BNP; panel A) and endothelin-1 (ET-1; panel B), were analyzed. H9c2 cells were pretreated with vehicle or various HS extracts (HS-Hex, HS-EA, and HS-H2O; 50 μg/mL) for 24 h, followed by cotreatment with Ang II (100 nM) for an additional 24 h. The results are presented as mean ± SEM (n = 6). Statistical analysis revealed significant differences: * p < 0.05 compared with untreated controls; # p < 0.05 compared with cells treated with Ang II alone. These data support the potential of HS extracts in modulating neurohormonal markers associated with HF progression.
Life 15 01229 g008
Life 15 01229 g009
Figure 9. Molecular Structures of Pure Compounds Isolated from HS Extracts. The figure displays the molecular structures of several pure compounds isolated from HS extracts, including β-sitosterol (HS-324), linoleic acid (HS-3253), 2-linoleodistearin (HS-3295), and syriacusin B (HS-3271). Adapted from the master’s thesis of Wei-Ping Chiang [39]. These structures confirm the chemical identities of isolated compounds used in functional assays.
Figure 9. Molecular Structures of Pure Compounds Isolated from HS Extracts. The figure displays the molecular structures of several pure compounds isolated from HS extracts, including β-sitosterol (HS-324), linoleic acid (HS-3253), 2-linoleodistearin (HS-3295), and syriacusin B (HS-3271). Adapted from the master’s thesis of Wei-Ping Chiang [39]. These structures confirm the chemical identities of isolated compounds used in functional assays.
Life 15 01229 g009
Table 1. Summary of reported biological activities of Hibiscus syriacus L.
Table 1. Summary of reported biological activities of Hibiscus syriacus L.
Plant Part UsedPreparation TypeReported Biological ActivityReference
Callus cultureExtractCytotoxicity in colorectal cancer via Notch-mediated cholesterol biosynthesis suppressionXu et al., 2022 [15]
Gold nanoparticle biosynthesisAnti-inflammatory effects via autophagy-dependent mechanismsXu et al., 2021 [19]
PetalsAnthocyanin-rich fractionInhibition of melanogenesis via ERK activationKarunarathne et al., 2019 [20]
AnthocyaninsProtection against oxidative stress via Nrf2/HO-1 activationMolagoda et al., 2020 [21]
Suppression of LPS-induced inflammation via TLR4/MD2-NFκB inhibitionKarunarathne et al., 2020 [22]
Inhibition of NLRP3 inflammasome via NFκB and ER stress modulationMolagoda et al., 2021 [23]
Anthocyanin-enriched polyphenolsAnti-osteoporotic effects via GSK-3β inhibition and β-catenin activationKarunarathne et al., 2021 [18]
Protection against UVB-induced skin damageKarunarathne et al., 2021 [6]
FlowerAbsolute extractEnhanced wound healing in keratinocytesYoon et al., 2017 [24]
Extract (clinical trial)Improved sleep quality in randomized controlled trialChoi et al., 2023 [3]
Flower, leaf, rootCrude extractsNutritional profiling and phytochemical screeningPark et al., 2022 [5]
Flower (light purple cultivar)ExtractAntimicrobial activity against plant pathogensSánchez-Hernández et al., 2021 [25]
Root barkEthanol extractAntidepressant-like and neuroprotective effectsKim et al., 2018 [26]
Isolated triterpenoidsCytotoxicity against cancer cell linesShi et al., 2014 [27]
Root and stem barkEnzyme-treated extractAnti-photoaging effects via increased hydration and collagen synthesisYang et al., 2019 [28]
Whole plant (in silico/in vivo)ExtractAntidiabetic, antioxidant, and hepatoprotective propertiesZiyanok-Demirtas, 2024 [17]
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Chao, H.-H.; Cheng, T.-H.; Chen, C.-C.; Liu, J.-C.; Chen, J.-J.; Sung, L.-C. Hibiscus syriacus L. Exhibits Cardioprotective Activity via Anti-Inflammatory and Antioxidant Mechanisms in an In Vitro Model of Heart Failure. Life 2025, 15, 1229. https://doi.org/10.3390/life15081229

AMA Style

Chao H-H, Cheng T-H, Chen C-C, Liu J-C, Chen J-J, Sung L-C. Hibiscus syriacus L. Exhibits Cardioprotective Activity via Anti-Inflammatory and Antioxidant Mechanisms in an In Vitro Model of Heart Failure. Life. 2025; 15(8):1229. https://doi.org/10.3390/life15081229

Chicago/Turabian Style

Chao, Hung-Hsin, Tzu-Hurng Cheng, Chun-Chao Chen, Ju-Chi Liu, Jin-Jer Chen, and Li-Chin Sung. 2025. "Hibiscus syriacus L. Exhibits Cardioprotective Activity via Anti-Inflammatory and Antioxidant Mechanisms in an In Vitro Model of Heart Failure" Life 15, no. 8: 1229. https://doi.org/10.3390/life15081229

APA Style

Chao, H.-H., Cheng, T.-H., Chen, C.-C., Liu, J.-C., Chen, J.-J., & Sung, L.-C. (2025). Hibiscus syriacus L. Exhibits Cardioprotective Activity via Anti-Inflammatory and Antioxidant Mechanisms in an In Vitro Model of Heart Failure. Life, 15(8), 1229. https://doi.org/10.3390/life15081229

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop