Aurantio-obtusin, an anthraquinone from cassiae semen, ameliorates lung inflammatory responses

Aurantio-Obtusin Regulates Gut Microbiota and Serum Metabolism to Alleviate High-Fat Diet-Induced Obesity-Associated Non-Alcoholic Fatty Liver Disease in Mice

Non-alcoholic fatty liver disease (NAFLD) is a progressive condition with limited effective treatments. This study investigated the therapeutic effects of Aurantio-obtusin (AO), a bioactive compound from Cassiae Semen, on obesity-associated NAFLD. An obesity-related NAFLD model was established in ApoE -/- mice fed a high-fat diet (HFD) for 24 weeks, with AO administered during the last 16 weeks. Mouse body weight, adipose tissue weights, liver weights, serum lipid levels, hepatic steatosis, inflammatory damage, and colonic tissue barrier integrity were evaluated. Gut microbial communities and serum metabolic profiles were analyzed using 16S rRNA sequencing and untargeted metabolomics. Hepatic lipid metabolism-related gene expression was assessed using molecular biology techniques. AO treatment significantly ameliorated HFD-induced adiposity, hyperlipidemia, and NAFLD symptoms. It preserved intestinal barrier integrity, modulated gut microbial composition by enriching beneficial taxa, and improved serum metabolic profiles. AO favorably adjusted hepatic lipid metabolism by upregulating PPARα and CPT1A while downregulating SREBP1, FASN, and SCD1. Correlation analysis revealed significant associations among gut microbial composition, serum metabolites, and disease indicators. AO's therapeutic benefits in NAFLD might be attributed to its ability to modulate gut microbial community composition and serum metabolic profile, enhance intestinal barrier function, and regulate hepatic lipid metabolism gene expression. AO presents a promising therapeutic agent for obesity-associated NAFLD, warranting further investigation into its potential clinical applications.

Inhibitory effects of cassiae semen extract on the formation of 2-amino-1-methyl-6-phenylimidazo [4,5-b] pyridine (PhIP) in model system

Introduction

2-Amino-1-methyl-6-phenylimidazole [4,5-b] pyridine (PhIP), a heterocyclic amine (HAA), is found in meat products heated at high temperatures. However, PhIP is a mutagenic and potential carcinogenic compound. Cassiae semen, a type of medicine and food homology plant, is abundant in China and has been less applied for inhibiting heterocyclic amines.

Methods

To investigate the inhibitory effect of cassiae semen extract on PhIP formation within a model system and elucidate the inhibitory mechanism, an ultrasonic-assisted method with 70% ethanol was used to obtain cassiae semen extract, which was added to a model system (0.6 mmol of phenylalanine: creatinine, 1:1). PhIP was analyzed by LC-MS to determine inhibitory effect. The byproducts of the system and the mechanism of PhIP inhibition were verified by adding the extract to a model mixture of phenylacetaldehyde, phenylacetaldehyde and creatinine.

Results

The results indicated that PhIP production decreased as the concentration of cassiae semen extract increased, and the highest inhibition rate was 91.9%. Byproduct (E), with a mass-charge ratio of m/z 199.9, was detected in the phenylalanine and creatinine model system but was not detected in the other systems. The cassiae semen extract may have reacted with phenylalanine to produce byproduct (E), which prevented the degradation of phenylalanine by the Strecker reaction to produce phenylacetaldehyde.

Discussion

Cassiae semen extract consumed phenylalanine, which is the precursor for PhIP, thus inhibiting the formation of phenylacetaldehyde and ultimately inhibiting PhIP formation. The main objective of this study was to elucidate the mechanism by which cassiae semen inhibit PhIP formation and establish a theoretical and scientific foundation for practical control measures.

Aurantio-obtusin Alleviates Dry Eye Disease by Targeting NF-κB/NLRP3 Signaling in Rodent Models

Dry eye disease (DED) is a common inflammatory ocular surface disorder, seriously affecting the quality of life of patients. Aurantio-obtusin (AO) is a bioactive anthraquinone compound isolated from Semen Cassiae which has multiple pharmacological activities. Nonetheless, the specific function of AO in DED is unclarified. In this study, a rodent DED model was established by benzalkonium chloride (BAC) induction, followed by topical administration of AO. The results showed that topical application of AO increased tear production, mitigated ocular surface disruption and maintained the number of goblet cells in BAC-induced DED rats (p˂0.05). ELISA revealed that AO treatment significantly (p˂0.001) reduced the production of proinflammatory cytokines and chemokines in the conjunctiva and cornea of BAC-induced DED rats. Immunohistochemical staining and western blotting showed that AO treatment suppressed the expression levels of NLR family pyrin domain containing 3 (NLRP3) inflammasome-related proteins, and inhibited activation of nuclear factor kappa B (NF-κB) signaling pathway in rat conjunctiva and cornea (p˂0.001). In conclusion, AO treatment alleviates BAC-induced DED in rats by inhibiting NF-κB/NLRP3 inflammasome signaling pathway.

Aurantio-obtusin exerts an anti-inflammatory effect on acute kidney injury by inhibiting NF-κB pathway

Acute kidney injury (AKI) is one of the major complications of sepsis. Aurantio-obtusin (AO) is an anthraquinone compound with antioxidant and anti-inflammatory activities. This study was developed to concentrate on the role and mechanism of AO in sepsis-induced AKI. Lipopolysaccharide (LPS)-stimulated human renal proximal tubular epithelial cells (HK-2) and BALB/c mice receiving cecal ligation and puncture (CLP) surgery were used to establish in vitro cell model and in vivo mouse model. HK-2 cell viability was measured using MTT assays. Histological alterations of mouse renal tissues were analyzed via hematoxylin and eosin staining. Renal function of mice was assessed by measuring the levels of serum creatinine (SCr) and blood urea nitrogen (BUN). The concentrations of pro-inflammatory cytokines in HK-2 cells and serum samples of mice were detected using corresponding ELISA kits. Protein levels of factors associated with nuclear factor kappa-B (NF-κB) pathway were measured in HK-2 cells and renal tissues by Western blotting. AO exerted no cytotoxic effect on HK-2 cells and AO dose-dependently rescued LPS-induced decrease in HK-2 cell viability. The concentrations of pro-inflammatory cytokines were increased in response to LPS or CLP treatment, and the alterations were reversed by AO treatment. For in vivo experiments, AO markedly ameliorated renal injury and reduced high levels of SCr and BUN in mice underwent CLP operation. In addition, AO administration inhibited the activation of NF-κB signaling pathway in vitro and in vivo. In conclusion, AO alleviates septic AKI by suppressing inflammatory responses through inhibiting the NF-κB pathway.

Chemical composition and absorption characteristics of Raw and Prepared Cassiae Semen extracts based on ultra-high-performance liquid chromatography-quadrupole Orbitrap high-resolution mass spectrometry

In traditional Chinese medicine, the two commodity forms of Cassiae Semen Raw and Prepared Cassiae Semen, exert different clinical applications, in which Prepared Cassiae Semen is commonly used to treat liver and eye diseases. However, the material basis of Raw and Prepared Cassiae Semen remains unclear due to the limited studies on their overall composition and metabolism in vivo. In this study, an integrated analysis strategy based on ultra-high-performance liquid chromatography coupled with quadrupole-Orbitrap high-resolution mass spectrometry was established to systematically screen the prototype and metabolite constituents of Raw and Prepared Cassiae Semen. Automatic matching analysis of metabolites was performed on Compound Discoverer software based on the function of predicting metabolites. Using this strategy, a total of 77 compounds in Raw Cassiae Semen and 71 compounds in Prepared Cassiae Semen were identified. Furthermore, in vivo study, 46 prototype components and 104 metabolites from the Raw Cassiae Semen group and 41 prototype components and 87 metabolites from the Prepared Cassiae Semen group were unambiguously or preliminarily identified in mice (plasma, urine, feces, eye, and liver). This is the first study of chemical component analysis and in vivo metabolite profiling of Raw and Prepared Cassiae Semen.

Medicinal plants of the upper Aswa River catchment of northern Uganda - a cultural crossroads

BACKGROUND

This paper presents a comparative inventory of medicinal plant taxa and their uses by smallholder farming communities of four cultures in the Aswa River catchment of northern Uganda, situated in the eastern Sudanian savanna parkland ecotype of sub-Saharan Africa. The purpose of the study was to document the ethnobotanical use of medicinal plants by the Lango, Acholi, Teso (Atesot) and Ethur (jo Abwor), in an historical moment before civil conflict and mass displacement of the respondent communities disrupted the inter-generational transmission of traditional technical knowledge within the study area.

METHODS

Following community consultations in four districts of northern Uganda during 1999-2000, interviews were conducted with holders of specialist knowledge on plants used as medicine on basis of a plant specimen allocated a voucher number and identified by the national herbarium. Use reports reflecting specific medicinal applications were compiled in aggregate to obtain a Relative Importance Index ranking. The commonality of medicinal taxa cited between each cultural interface was assessed by the Jaccard Index of Similarity, and the similarity of specific medicinal usage by taxon using Rahman's Similarity Index.

RESULTS

The data collected from 112 respondents comprise 280 medicinal use reports describing 263 applications for 62 medical conditions, citing 108 taxa from 44 botanical families of which Fabaceae comprised 20% of all use reports. No earlier mention could be found to corroborate 72 use reports (27% of the total), representing medicinal indications as yet undocumented, and potentially worthy of investigation. The RI values ranged between 15 and 94%, with 13 taxa having RI values above 50%. The JI ratios indicate the highest degree of similarity in the plant taxa used as medicine (21%) between the Lango and Teso cultures who share a common origin; however, Rahman's Similarity Index indicates the highest similarity of specific medicinal usage by taxon between the Lango and Acholi, who share a common language group through cultural assimilation over time.

CONCLUSIONS

As a comparative study, the results imply that cultural exchange and assimilation may be a greater driver of inter-cultural similarity of ethnopharmacological use of a given taxon, as compared to shared historical origins.

Effect Assessment of Aurantio-Obtusin on Novel Human Renal Glomerular Endothelial Cells Model Using a Microfluidic Chip

Cassiae semen is widely used as a raw material of health food. Anthraquinone compounds, the main components in cassiae semen, have been reported to show nephrotoxicity. Aurantio-obtusin (AO) is a major anthraquinone compound extracted from cassiae semen. This study investigates the effects of AO on the morphology and physiological function of human renal glomerular endothelial cells (HRGECs) on a microfluidic chip device for the first time. HRGECs were cultured on a microfluidic plate and exposed to a series of AO concentrations. Compared with traditional 96-well culture, HRGECs cultured on the microfluidic chip appeared to better mimic the glomerular microenvironment in vivo. AO induced different degrees of damage to cellular morphology and physiological function. The leakage of lactate dehydrogenase (LDH), as well as the secretion of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), transforming growth factor-β1 (TGF-β1), and monocyte chemoattractant protein 1 (MCP-1), increased in the AO treated groups. At the same time, cell viability and expression of ZO-1 in the AO treated groups decreased in a dose-dependent manner. The innovative device enables direct visualization and quantification to evaluate the cytotoxic effects of AO on HRGECs, and provides a useful visual in vitro model for studying health effect of health food.

Aurantio-Obtusin Attenuates Non-Alcoholic Fatty Liver Disease Through AMPK-Mediated Autophagy and Fatty Acid Oxidation Pathways

Nonalcoholic fatty liver disease (NAFLD), manifested as the aberrant accumulation of lipids in hepatocytes and inflammation, has become an important cause of advanced liver diseases and hepatic malignancies worldwide. However, no effective therapy has been approved yet. Aurantio-obtusin (AO) is a main bioactive compound isolated from Cassia semen that has been identified with multiple pharmacological activities, including improving adiposity and insulin resistance. However, the ameliorating effects of AO on diet-induced NAFLD and underlying mechanisms remained poorly elucidated. Our results demonstrated that AO significantly alleviated high-fat diet and glucose-fructose water (HFSW)-induced hepatic steatosis in mice and oleic acid and palmitic acid (OAPA)-induced lipid accumulation in hepatocytes. Remarkably, AO was found to distinctly promote autophagy flux and influence the degradation of lipid droplets by inducing AMPK phosphorylation. Additionally, the induction of AMPK triggered TFEB activation and promoted fatty acid oxidation (FAO) by activating PPARα and ACOX1 and decreasing the expression of genes involved in lipid biosynthesis. Meanwhile, the lipid-lowing effect of AO was significantly prevented by the pretreatment with inhibitors of autophagy, PPARα or ACOX1, respectively. Collectively, our study suggests that AO ameliorates hepatic steatosis via AMPK/autophagy- and AMPK/TFEB-mediated suppression of lipid accumulation, which opens new opportunities for pharmacological treatment of NAFLD and associated complications.

Transcriptome and HPLC Analysis Reveal the Regulatory Mechanisms of Aurantio-Obtusin in Space Environment-Induced Senna obtusifolia Lines

Senna obtusifolia is a famous medicinal plant that is widely used in Asian countries. Its seed plays an important role in the treatment of many diseases because it contains various anthraquinones and flavonoids. Our previous studies have indicated that three space environment-induced S. obtusifolia lines (SP-lines) i.e., QC10, QC29, and QC46, have higher seed yield and aurantio-obtusin (AO) content. However, the underlying mechanism of higher AO content in SP-lines is still unknown. Herein, transcriptome sequencing and HPLC were employed to analyze the differences between SP-lines and ground control (GC3) and elucidate the regulatory mechanisms of AO accumulation in SP-lines. The results show that 4002 differentially expressed genes (DEGs) were identified in SP-lines versus (vs.) GC3. DEGs in the QC10 vs. GC3, QC29 vs. GC3, and QC46 vs. GC3 comparisons were classified into 28, 36, and 81 GO terms and involved in 63, 74, and 107 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. KEGG pathway and gene expression analysis revealed that DEGs involved in anthraquinone pathways were significantly elevated in QC10 and QC46. Integrating the results of GO annotation, KEGG enrichment, and gene expression analysis, we propose that the elevated genes such as DAHPS, DHQS, and MenB enhance the metabolic flux in the anthraquinone pathway and promote AO content in QC10 and QC46. Taken together, this study elucidated the mechanism of AO content in SP-lines and provides valuable genetic information for S. obtusifolia. In addition, to the best of our knowledge, this study presents the first transcriptome analysis of environment-induced medicinal plants and paves the way to select elite S. obtusifolia varieties in the future.

Aurantio-obtusin induces hepatotoxicity through activation of NLRP3 inflammasome signaling

Aurantio-obtusin (AO) is a major anthraquinone (AQ) compound derived from Cassiae semen (CS). Although pharmacological studies have shown that the CS extracts can serve as effective agents in preclinical and clinical practice, AQ-induced hepatotoxicity in humans has attracted widespread attention. To explore whether AO induces hepatotoxicity and its underlying mechanisms, we exposed larval zebrafish and mice to AO. We found that AO delayed yolk sac absorption, and increased liver area and inflammation in the larval zebrafish. This inflammation was manifested as an increase in liver neutrophils and the up-regulated mRNA expression of interleukin-6 (Il-6) and tumor necrosis factor-α (Tnf-α) in the larval zebrafish. Furthermore, a pharmacokinetics study showed that AO was quickly absorbed into the blood and rapidly metabolized in the mice. Of note, AO induced hepatotoxicity in a gender-dependent manner, characterized by liver dysfunction, increased hepatocyte necrosis with inflammatory infiltration, and up-regulated mRNAs of Il-6, Tnf-α and monocyte chemotactic protein 1(Mcp1) in the female mice after 28-day oral administration. It also highlighted that AO triggered NOD-like receptor protein (NLRP) signaling in the female mice, as evidenced by the increased NLRP3, Caspase-1, pro-IL-1β, IL-1β and IL-18. Finally, we found that AO led to a significant increase in potassium calcium-activated channel, subfamily N, member 4 (KCNN4) and reactive oxygen species (ROS) levels, along with decreased nuclear factor kappa B p65 (NF-κB p65), in the female mouse livers. In conclusion, AO induced hepatotoxicity by activating NLRP3 inflammasome signaling, at least in part, through increased KCNN4 and ROS production, and NF-κB inhibition.

Phytochemistry, Ethnopharmacological Uses, Biological Activities, and Therapeutic Applications of Cassia obtusifolia L.: A Comprehensive Review

Cassia obtusifolia L., of the Leguminosae family, is used as a diuretic, laxative, tonic, purgative, and natural remedy for treating headache, dizziness, constipation, tophobia, and lacrimation and for improving eyesight. It is commonly used in tea in Korea. Various anthraquinone derivatives make up its main chemical constituents: emodin, chrysophanol, physcion, obtusifolin, obtusin, au rantio-obtusin, chryso-obtusin, alaternin, questin, aloe-emodin, gluco-aurantio-obtusin, gluco-obtusifolin, naphthopyrone glycosides, toralactone-9-β-gentiobioside, toralactone gentiobioside, and cassiaside. C. obtusifolia L. possesses a wide range of pharmacological properties (e.g., antidiabetic, antimicrobial, anti-inflammatory, hepatoprotective, and neuroprotective properties) and may be used to treat Alzheimer's disease, Parkinson's disease, and cancer. In addition, C. obtusifolia L. contributes to histamine release and antiplatelet aggregation. This review summarizes the botanical, phytochemical, and pharmacological features of C. obtusifolia and its therapeutic uses.

How does traditional knowledge of Cassiae semen shed light on weight management? - A classical and modern literature review

ETHNOPHARMACOLOGICAL RELEVANCE

The seed of Senna obtusifolia (L.) H. S. Irwin & Barneby (Cassiae semen, CS) also known as Jue ming zi in China, has been traditionally used for weight management by purging the liver and improving the liver functions to support digestion. In the past decades, it has been used for hepatoprotection and treatment of overweight and other metabolic disorders such as hyperlipidaemia and diabetes.

AIM OF THE REVIEW

This review aimed at providing comprehensive information on the traditional usages, pharmacology, phytochemistry and toxicology of CS and critically exploring its potential usage for clinical weight management from both traditional and modern application perspectives.

MATERIALS AND METHODS

In order to fully understand the properties, actions and indications of CS, two sets of Chinese classical texts were searched, namely: Zhong Hua Yi Dian (Encyclopedia of Traditional Chinese Medicine) and Zhong Guo Ben Cao Quan Shu (Complete Collection of Traditional Texts on Chinese Materia Medica). The purpose of studying these classical texts was to determine the traditional use of CS in weight management. Comprehensive searches were also performed on seven databases for publications on original randomised clinical trials (RCT), in vivo, in vitro or in silico studies related to pharmacological effects of CS. Detailed information about the phytochemistry of CS was collected from books, encyclopedia, online databases and journal literature.

FINDINGS

In classical literature review, 89 classic texts provided information of properties, actions and indications of CS. In modern literature review, 44 studies were included for analysis, including 5 RCTs, 7 in vivo studies, 14 in vitro studies, 2 in silico studies and 16 studies of mixed types. Chinese classic literature has provided traditional evidence of the usage of CS for weight management. Contemporary studies have revealed that CS has weight loss effects and possesses some other pharmacological activities supporting weight management. Some chemical compounds of CS have been hypothesised to have a direct or indirect contribution to weight control.

CONCLUSIONS

The relationships between chemical compounds and the corresponding weight-loss target proteins are not fully understood. Therefore, CS constituents should be further explored for the development of novel therapeutic or preventive agents for the treatment of overweight and obesity.

Neuroprotective Effect of Aurantio-Obtusin, a Putative Vasopressin V1A Receptor Antagonist, on Transient Forebrain Ischemia Mice Model

Traditional Chinese medicines (TCMs) have been a rich source of novel drug discovery, and Cassia seed is one of the common TCMs with numerous biological effects. Based on the existing reports on neuroprotection by Cassia seed extract, the present study aims to search possible pharmacological targets behind the neuroprotective effects of the Cassia seeds by evaluating the functional effect of specific Cassia compounds on various G-protein-coupled receptors. Among the four test compounds (cassiaside, rubrofusarin gentiobioside, aurantio-obtusin, and 2-hydroxyemodin 1-methylether), only aurantio-obtusin demonstrated a specific V_1AR antagonist effect (71.80 ± 6.0% inhibition at 100 µM) and yielded an IC₅₀ value of 67.70 ± 2.41 μM. A molecular docking study predicted an additional interaction of the hydroxyl group at C6 and a methoxy group at C7 of aurantio-obtusin with the Ser341 residue as functional for the observed antagonist effect. In the transient brain ischemia/reperfusion injury C57BL/6 mice model, aurantio-obtusin attenuated the latency time that was reduced in the bilateral common carotid artery occlusion (BCCAO) groups. Likewise, compared to neuronal damage in the BCCAO groups, treatment with aurantio-obtusin (10 mg/kg, p.o.) significantly reduced the severity of damage in medial cornu ammonis 1 (mCA1), dorsal CA1, and cortex regions. Overall, the findings of this study highlight V_1AR as a possible target of aurantio-obtusin for neuroprotection.

Natural Antioxidants Improve the Vulnerability of Cardiomyocytes and Vascular Endothelial Cells under Stress Conditions: A Focus on Mitochondrial Quality Control

Cardiovascular disease has become one of the main causes of human death. In addition, many cardiovascular diseases are accompanied by a series of irreversible damages that lead to organ and vascular complications. In recent years, the potential therapeutic strategy of natural antioxidants in the treatment of cardiovascular diseases through mitochondrial quality control has received extensive attention. Mitochondria are the main site of energy metabolism in eukaryotic cells, including myocardial and vascular endothelial cells. Mitochondrial quality control processes ensure normal activities of mitochondria and cells by maintaining stable mitochondrial quantity and quality, thus protecting myocardial and endothelial cells against stress. Various stresses can affect mitochondrial morphology and function. Natural antioxidants extracted from plants and natural medicines are becoming increasingly common in the clinical treatment of diseases, especially in the treatment of cardiovascular diseases. Natural antioxidants can effectively protect myocardial and endothelial cells from stress-induced injury by regulating mitochondrial quality control, and their safety and effectiveness have been preliminarily verified. This review summarises the damage mechanisms of various stresses in cardiomyocytes and vascular endothelial cells and the mechanisms of natural antioxidants in improving the vulnerability of these cell types to stress by regulating mitochondrial quality control. This review is aimed at paving the way for novel treatments for cardiovascular diseases and the development of natural antioxidant drugs.

A comparative study of aurantio-obtusin metabolism in normal and liver-injured rats by ultra performance liquid chromatography quadrupole time-of-flight mass spectrometry

Aurantio-obtusin, an anthraquinone isolated from cassiae semen, possesses diverse pharmacological activities, including hypotensive, hypolipidemic and anti-inflammatory effects. However, our previous studies demonstrated that exposure to aurantio-obtusin induced hepatotoxicity, but the mechanisms of the toxic effects remain unknown. The purpose of the present study is to establish a strategy for the metabolite profiling of aurantio-obtusin in normal and liver-injured rats. This study aimed at identifying the in vivo metabolites and the metabolic profiling in rats after oral administration at a dose of aurantio-obtusin (4 and 200 mg/kg) by using an ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) and metabolynx™ software. A total of 39 metabolites were detected and 3 of them were compared with standard substances. The results indicated that the principal metabolism pathways of aurantio-obtusin in normal rats were glucuronidation and sulfation, while in rats with liver injury, demethylation, dehydroxylation and reduction were also observed and regarded as new metabolic patterns of aurantio-obtusin. These findings helped us to understand the pharmacological and toxicological mechanisms of aurantio-obtusin. Moreover, this study could help to elucidate the metabolic profiling of other anthraquinones.

Natural product derived phytochemicals in managing acute lung injury by multiple mechanisms

Acute lung injury (ALI) and its more severe form, acute respiratory distress syndrome (ARDS) as common life-threatening lung diseases with high mortality rates are mostly associated with acute and severe inflammation in lungs. With increasing in-depth studies of ALI/ARDS, significant breakthroughs have been made, however, there are still no effective pharmacological therapies for treatment of ALI/ARDS. Especially, the novel coronavirus pneumonia (COVID-19) is ravaging the globe, and causes severe respiratory distress syndrome. Therefore, developing new drugs for therapy of ALI/ARDS is in great demand, which might also be helpful for treatment of COVID-19. Natural compounds have always inspired drug development, and numerous natural products have shown potential therapeutic effects on ALI/ARDS. Therefore, this review focuses on the potential therapeutic effects of natural compounds on ALI and the underlying mechanisms. Overall, the review discusses 159 compounds and summarizes more than 400 references to present the protective effects of natural compounds against ALI and the underlying mechanism.

Kanglexin, a new anthraquinone compound, attenuates lipid accumulation by activating the AMPK/SREBP-2/PCSK9/LDLR signalling pathway

Hyperlipidaemia is one of the major risk factors for atherosclerosis, coronary heart disease, stroke and diabetes. In the present study, we synthesized a new anthraquinone compound, 1,8-dihydroxy-3-succinic acid monoethyl ester-6-methylanthraquinone, and named it Kanglexin (KLX). The aim of this study was to evaluate whether KLX has a lipid-lowering effect and to explore the potential molecular mechanism. In this study, Sprague-Dawley rats were fed a high fat diet (HFD) for 5 weeks to establish a hyperlipidaemia model; then, the rats were orally administered KLX (20, 40, and 80 mg kg-1·d-1) or atorvastatin calcium (AT, 10 mg kg-1·d-1) once a day for 2 weeks. KLX had prominent effects on reducing blood lipids, hepatic lipid accumulation, body weight and the ratio of liver weight/body weight. Furthermore, KLXdramatically reduced the total cholesterol (TC) and triglyceride (TG) levels and lipid accumulation in a HepG2 cell model of dyslipidaemia induced by 1 mmol/L oleic acid (OA). KLX may decrease lipid levels by phosphorylating adenosine monophosphate-activated protein kinase (AMPK) and the downstream sterol regulatory element binding protein 2 (SREBP-2)/proprotein convertase subtilisin/kexin type 9 (PCSK9)/low-density lipoprotein receptor (LDLR) signalling pathway in the HFD rats and OA-treated HepG2 cells. The effects of KLX on the AMPK/SREBP-2/PCSK9/LDLR signalling pathway were abolished when AMPK was inhibited by compound C (a specific AMPK inhibitor) in HepG2 cells. In summary, KLX has an efficient lipid-lowering effect mediated by activation of the AMPK/SREBP-2/PCSK9/LDLR signalling pathway. Our findings may provide new insight into and evidence for the discovery of a new lipid-lowering drug for the prevention and treatment of hyperlipidaemia, fatty liver, and cardiovascular disease in the clinic.

The Metabolism and Pharmacokinetics of Rhein and Aurantio-Obtusin

BACKGROUND

Anthraquinones, rhein and aurantio-obtusin were isolated from the herb Duhaldea nervosa for the first time by our group, which were also found in plants that belong to the plant family Compositae. Anthraquinone compounds have a range of pharmacological activities such as anti-inflammatory, anti-cancer, antioxidation, anti-diabetes, etc. and can be used as a laxative, for liver protection, treatment of chronic renal failure, etc. However, in recent years, anthraquinones have been reported to be cytotoxic to the liver and kidneys. Therefore, it is very important to study the pharmacokinetics and metabolism of rhein and aurantio-obtusin, which are common ingredients in many traditional Chinese medicines (TCM). According to our research, the pharmacokinetics and metabolism of rhein and aurantio-obtusin are comprehensively summarized in the paper for the first time.

OBJECTIVE

The study provides comprehensive information on pharmacokinetics and metabolism of rhein and aurantio- obtusin in different Species; meanwhile, the aim of this review is also to provide a reference for a reasonable application of TCM enriched with these two ingredients.

METHODS

The metabolism and pharmacokinetics of rhein and aurantio-obtusin were searched by the Web of Science, PubMed, Google scholar and some Chinese literature databases.

RESULTS

Rhein and aurantio-obtusin exist mainly in the form of metabolites in the body. Rhein and aurantio-obtusin and its metabolites might be responsible for pharmacological effects in the body. Therefore, the significance of studying the in vivo metabolites of rhein and aurantio-obtusin is not only essential to clarify their pharmacological mechanism, but also to find new active compound ingredients. The metabolism of rhein is different in different species, so the toxicity effects of rhein may also be different after oral administration in different species; however, the metabolic profiles of aurantio-obtusin in the liver microsomes of different species are similar.

CONCLUSION

This paper not only provides detail regarding the pharmacokinetics of rhein and aurantio-obtusin, but it is anticipated that it will also facilitate further study on the metabolism of rhein and aurantio-obtusin.

Mitochondrial Targeting in an Anti-Austerity Approach Involving Bioactive Metabolites Isolated from the Marine-Derived Fungus Aspergillus sp

The tumor microenvironment is a nutrient-deficient region that alters the cancer cell phenotype to aggravate cancer pathology. The ability of cancer cells to tolerate nutrient starvation is referred to as austerity. Compounds that preferentially target cancer cells growing under nutrient-deficient conditions are being employed in anti-austerity approaches in anticancer drug discovery. Therefore, in this study, we investigated physcion (1) and 2-(2',3-epoxy-1',3',5'-heptatrienyl)-6-hydroxy-5-(3-methyl-2-butenyl) benzaldehyde (2) obtained from a culture extract of the marine-derived fungus Aspergillus species (sp.), which were isolated from an unidentified marine sponge, as anti-austerity agents. The chemical structures of 1 and 2 were determined via spectroscopic analysis and comparison with authentic spectral data. Compounds 1 and 2 exhibited selective cytotoxicity against human pancreatic carcinoma PANC-1 cells cultured under glucose-deficient conditions, with IC₅₀ values of 6.0 and 1.7 µM, respectively. Compound 2 showed higher selective growth-inhibitory activity (505-fold higher) under glucose-deficient conditions than under general culture conditions. Further analysis of the mechanism underlying the anti-austerity activity of compounds 1 and 2 against glucose-starved PANC-1 cells suggested that they inhibited the mitochondrial electron transport chain.

Urine Metabolomics Study on Potential Hepatoxic Biomarkers Identification in Rats Induced by Aurantio-Obtusin

Previous studies revealed the hepatotoxic effect of aurantio-obtusin on rats. The aim of this study was to identify potential biomarkers of urine caused by aurantio-obtusin. Sprague–Dawley (SD) rats with body weight of 0, 4, 40, and 200 mg/kg were orally given aurantio-obtusin for 28 days, and urine was collected for 24 h after the last administration. The urine metabolites in the aurantio-obtusin group and the control group were analyzed by ultraperformance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS). Twenty-three metabolites were identified as potential biomarkers, and 10 of them were up-regulated, including xanthosine, hippuric acid, 5-L-glutamyl-taurine, etc. The other 13 biomarkers were down-regulated, including thymidine, 3-methyldioxyindole, cholic acid, etc. The significant changes of these biomarkers indicated that purine metabolism, taurine and hypotaurine metabolism, primary bile acid biosynthesis, pyrimidine metabolism, and tryptophan metabolism played an important role in the hepatotoxicity of aurantio-obtusin in rats. In this paper, the safety and potential risk of aurantio-obtusin were studied for the first time by combining the toxicity of aurantio-obtusin with the results of urine metabolomics, which provided information for the mechanism of liver injury induced by aurantio-obtusin.

Chrysophanic acid shifts the differentiation tendency of BMSCs to prevent alcohol-induced osteonecrosis of the femoral head

Objectives

Osteonecrosis of the femoral head (ONFH), largely caused by alcohol abuse, is a refractory bone disease characterized by the impaired capacity of osteogenic differentiation of bone mesenchymal stem cells (BMSCs), as well as the disordered adipocyte accumulation. Chrysophanic acid (CPA) is a natural anthraquinone which has lipid regulation and bone protection capacity. The aim of this study was to reveal the potential function of CPA and the underlying mechanisms for the alcohol‐induced ONFH.

Materials and Methods

The effects of alcohol and CPA on BMSCs were investigated by cell proliferation, induced differentiation assays and immunofluorescent staining. Meanwhile, the function of PI3K/AKT and AMPK pathway was investigated in the process of osteogenic and adipogenic differentiation, respectively. Furthermore, we established the rat model of alcohol‐induced ONFH to reveal the pharmacotherapeutic effect of CPA in vivo using radiographical and histopathological methods.

Results

In vitro, alcohol significantly inhibited the proliferation and osteogenic differentiation of BMSCs but stimulated the adipogenic differentiation. However, CPA could counteract the anti‐osteogenesis of alcohol partly via PI3K/AKT pathway and retard the promotion of alcohol‐induced adipogenesis via AMPK pathway. In vivo, radiographical and histopathological findings showed that CPA could alleviate alcohol‐induced ONFH and substantially restore the bone volume.

Conclusions

We demonstrated that CPA ameliorated alcohol‐induced ONFH possibly via regulating the differentiation tendency of BMSCs. Hence, CPA may become a beneficial herb extract to alleviate alcohol‐induced ONFH.

Inhibitory Mechanisms of Water Extract of Oplopanax elatus on Lipopolysaccharide-Induced Inflammatory Responses in RAW 264.7 Murine Macrophage Cells

OBJECTIVE

To study the anti-inflammatory action and cellular mechanism of Oplopanax elatus.

METHODS

A hot water extract of OE (WOE) was prepared and a major constituent, syringin, was successfully isolated. Its content in WOE was found to be 214.0 µg/g dried plant (w/w). Their anti-inflammatory activities were examined using RAW 264.7 macrophages and a mouse model of croton oil-induced ear edema.

RESULTS

In lipopolysaccharide (LPS)-treated RAW 264.7 cells, a mouse macrophage cell line, WOE was found to significantly and strongly inhibit cyclooxygenase-2 (COX-2)-induced prostaglandin E₂ (PGE₂) production [half maximal inhibitory concentration (IC₅₀)=135.2 µg/mL] and inducible nitric oxide synthase (iNOS)-induced NO production (IC₅₀=242.9 µg/mL). In the same condition, WOE was revealed to inhibit NO production by down-regulating iNOS expression, mainly by interrupting mitogen activated protein kinases (MAPKs)/activator protein-1 (AP-1) pathway. The activation of all three major MAPKs, p38 MAPK, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase, was inhibited by WOE (50-300 µg/mL). On the other hand, WOE reduced PGE₂ production by inhibiting COX-2 enzyme activity, but did not affect COX-2 expression levels. In addition, WOE inhibited the production of proinflammatory cytokines such as interleukin-6 and tumor necrosis factor-α. In croton oil-induced ear edema in mice, oral administration of WOE (50-300 mg/kg) dose-dependently inhibited edematic inflammation.

CONCLUSION

Water extract of OE exhibited multiple anti-inflammatory action mechanisms and may have potential for treating inflammatory disorders.

Hepatoprotective effects of Cassia semen ethanol extract on non-alcoholic fatty liver disease in experimental rat

CONTEXT

Cassia semen (Cs), a seed of Cassia obtusifolia L. (Leguminosae), is a popular functional beverage. Previous studies reported that Cs displayed antioxidant, antifungal and strong liver protective effects.

OBJECTIVE

This study evaluates the hepatoprotective effects of Cs on non-alcoholic fatty liver disease (NAFLD).

MATERIALS AND METHODS

Seventy-two male Wistar rats raised with high-fat diet (HFD) were randomly allotted into model, metformin (0.2 g/kg) and Cs (0.5, 1, and 2 g/kg)-treated groups. Another 12 rats were raised with normal feed as control group; all the rats were orally administrated with drugs and vehicle for 6 weeks. Alanine transferase (ALT), aspartate transaminase (AST), triglycerides (TG), total cholesterol (TC), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-8 and low density lipoprotein receptor (LDL-R) mRNA levels were measured at the end of the experiment.

RESULTS

Twelve weeks of HFD administration significantly increased the levels of AST, ALT, TG, TC, TNF-α, IL-6, IL-8 and MDA, decreased SOD (199.42 vs. 137.70 U/mg protein) and GSH (9.76 vs. 4.55 mg/g protein) contents, compared to control group. Cs administration group significantly decreased the elevated biomarkers with the ED₅₀ = 1.2 g/kg for NAFLD rats. Cs treatment also prevents the decreased expression of LDL-R mRNA, and improved the histopathological changes compared to model group.

CONCLUSIONS

The hepatoprotective effect of Cs on NAFLD may possibly be due to its antioxidant effect. Cs may become a potent hepatoprotective agent in clinical therapy in the future.

Metabolomics of Aurantio-Obtusin-Induced Hepatotoxicity in Rats for Discovery of Potential Biomarkers

Aurantio-obtusin is an anthraquinone derived from Cassia obtusifolia (cassiae semen). It is also used as a tool and a detection index for the identification of cassiae semen, as stipulated by the Chinese Pharmacopoeia. Anthraquinones, the main components in cassiae semen, have been reported to show hepatotoxicity. This study investigates the hepatotoxicity of aurantio-obtusin in male Sprague–Dawley rats. We randomly divided the animals into a blank control group and treated three test groups with different doses of aurantio-obtusin: Low dose (4 mg/kg), medium dose (40 mg/kg), and high dose (200 mg/kg). Each group was treated with aurantio-obtusin for 28 days, whereas the control group was administered an equal volume of 0.5% carboxymethyl cellulose sodium salt (CMC-Na) aqueous solution. Subsequently, we conducted biochemical, hematological, and pathological investigations and determined the weight of different organs. We used serum metabolomics to identify possible biomarkers related to hepatotoxicity. The low-dose group showed no significant liver injury, whereas the medium- and high-dose groups manifested obvious liver injury. Compared with the control group, the test groups showed an increase in alanine transaminase, aspartate transaminase, and alkaline phosphatase levels. The liver organ coefficient also significantly increased. Additionally, we found significant changes in the hematological indices. Metabolomics analysis showed that aurantio-obtusin induced 28 endogenous markers related to liver injury. Our data indicate that aurantio-obtusin induces hepatotoxicity in rat liver in a dose-dependent manner and is mediated by pathways involving bile acids, fatty acids, amino acids, and energy metabolism. In particular, changes in bile acid content during treatment with therapeutic agents containing aurantio-obtusin deserve increased attention.

Physcion and physcion 8-O-β-glucopyranoside: A review of their pharmacology, toxicities and pharmacokinetics

Anthraquinones constitute an important class of natural and synthetic compounds with a broad scope of pharmacological including anti-bacterial, antioxidant, laxative, anti-tumor and other activities. Physcion and physcion 8-O-β-glucopyranoside (PG) are common anthraquinones existed in various plants. Emerging studies suggested that physcion and PG not only exert anti-tumor, anti-microbial, anti-inflammatory, anti-oxidant, optical-related, enzyme inhibitory, lipid regulation and neuroprotective activities, but also lead to hepatotoxicity, renal toxicity and genetic damage. Besides, a growing number of pharmacokinetics researches of physcion and PG also have been conducted. However, no review of physcion or PG have been published by now, so the aim of present review is to give a comprehensive summary and analysis of the pharmacology, toxicity and pharmacokinetics of physcion and PG by consulting all the currently available literatures published in PubMed then give a future prospects about it.

Chrysophanol: a review of its pharmacology, toxicity and pharmacokinetics

OBJECTIVE

Chrysophanol is a natural anthraquinone, also known as chrysophanic acid and 1,8-dihydroxy-3-methyl-anthraquinone. It has been widely used in the food and pharmaceutical fields. This review is intended to provide a comprehensive overview of the pharmacology, toxicity and pharmacokinetic researches of chrysophanol.

KEY FINDING

Information on chrysophanol was collected from the Internet database PubMed, Elsevier, ResearchGate, Web of Science, Wiley Online Library and Europe PM using a combination of keywords including 'pharmacology', 'toxicology' and 'pharmacokinetics'. The literature we collected included from January 2010 to June 2019. Chrysophanol has a wide spectrum of pharmacological effects, including anticancer, antioxidation, neuroprotection, antibacterial and antiviral, and regulating blood lipids. However, chrysophanol has obvious hepatotoxicity and nephrotoxicity, and pharmacokinetics indicate that the use of chrysophanol in combination with other drugs can reduce toxicity and enhance efficacy.

SUMMARY

Chrysophanol can be used in many diseases. Future research directions include how the concentration of chrysophanol affects pharmacological effects and toxicity; the mechanism of synergy between chrysophanol and other drugs.

Separation of Protein-Binding Anthraquinones from Semen Cassiae Using Two-Stage Foam Fractionation

Anthraquinones are compounds of high medicinal value in many plants. Based on their good protein binding affinity, foam fractionation was attempted to separate them using proteins in the aqueous extract of Semen Cassiae as collectors. Firstly, the interaction between anthraquinones and Semen Cassiae proteins has been analyzed by the Stem–Volmer equation with physcion as a standard. The results show that physcion had good interaction with the proteins via hydrophobic forces. More importantly, the proteins effectively assisted the foam fractionation of several anthraquinones including aurantio-obtusifolin, aloe-emodin, rhein, emodin, chrysophanol, and physcion. On this basis, a two-stage foam fractionation technology was developed for process intensification using a foam fractionation with vertical sieve trays (VSTs). VSTs, initial feed concentration of total anthraquinones, temperature, volumetric air flow rate and pore diameter of gas distributor had significant effects on enrichment ratio and recovery yield of anthraquinones. Under suitable conditions, the enrichment ratio of total anthraquinones reached 47.0 ± 4.5 with a concentration of 939 ± 94 mg/L in the foamate while their total recovery percentage reached more than 47.7%. In addition, foam fractionation also increased the purity and hydroxyl radical scavenging activity of total anthraquinones. The results had significant implications for the separation of anthraquinones from Semen Cassiae.

Fushiming Capsule Attenuates Diabetic Rat Retina Damage via Antioxidation and Anti-Inflammation

AIMS

Diabetic retinopathy (DR) remains one of the leading causes of acquired blindness. Fushiming capsule (FSM), a compound traditional Chinese medicine, is clinically used for DR treatment in China. The present study was to investigate the effect of FSM on retinal alterations, inflammatory response, and oxidative stress triggered by diabetes.

MAIN METHODS

Diabetic rat model was induced by 6-week high-fat and high-sugar diet combined with 35 mg/kg streptozotocin (STZ). 30 days after successful establishment of diabetic rat model, full field electroretinography (ffERG) and optical coherence tomography (OCT) were performed to detect retinal pathological alterations. Then, FSM was administered to diabetic rats at different dosages for 42-day treatment and diabetic rats treated with Calcium dobesilate (CaD) capsule served as the positive group. Retinal function and structure were observed, and retinal vascular endothelial growth factor-α (VEGF-α), glial fibrillary acidic (GFAP), and vascular cell adhesion protein-1 (VCAM-1) expressions were measured both on mRNA and protein levels, and a series of blood metabolic indicators were also assessed.

KEY FINDINGS

In DR rats, FSM (1.0 g/kg and 0.5 g/kg) treatment significantly restored retinal function (a higher amplitude of b-wave in dark-adaptation 3.0 and OPs2 wave) and prevented the decrease of retinal thickness including inner nuclear layer (INL), outer nuclear layer (ONL), and entire retina. Additionally, FSM dramatically decreased VEGF-α, GFAP, and VCAM-1 expressions in retinal tissues. Moreover, FSM notably improved serum antioxidative enzymes glutathione peroxidase, superoxide dismutase, and catalase activities, whereas it reduced serum advanced glycation end products, methane dicarboxylic aldehyde, nitric oxide, and total cholesterol and triglycerides levels.

SIGNIFICANCE

FSM could ameliorate diabetic rat retina damage possibly via inhibiting inflammation and improving antioxidation.

Semen cassiae Extract Inhibits Contraction of Airway Smooth Muscle

β₂-adrenoceptor agonists are commonly used as bronchodilators to treat obstructive lung diseases such as asthma and chronic obstructive pulmonary disease (COPD), however, they induce severe side effects. Therefore, developing new bronchodilators is essential. Herbal plants were extracted and the extracts’ effect on airway smooth muscle (ASM) precontraction was assessed. The ethyl alcohol extract of semen cassiae (EESC) was extracted from Semen cassia. The effects of EESC on the ACh- and 80 mM K⁺-induced sustained precontraction in mouse and human ASM were evaluated. Ca²⁺ permeant ion channel currents and intracellular Ca²⁺ concentration were measured. HPLC analysis was employed to determine which compound was responsible for the EESC-induced relaxation. The EESC reversibly inhibited the ACh- and 80 mM K⁺-induced precontraction. The sustained precontraction depends on Ca²⁺ influx, and it was mediated by voltage-dependent L-type Ca²⁺ channels (LVDCCs), store-operated channels (SOCs), TRPC3/STIM/Orai channels. These channels were inhibited by aurantio-obtusin, one component of EESC. When aurantio-obtusin removed, EESC’s action disappeared. In addition, aurantio-obtusin inhibited the precontraction of mouse and human ASM and intracellular Ca²⁺ increases. These results indicate that Semen cassia-contained aurantio-obtusin inhibits sustained precontraction of ASM via inhibiting Ca²⁺-permeant ion channels, thereby, which could be used to develop new bronchodilators.