Cycloastragenol, a triterpene aglycone derived from Radix astragali, suppresses the accumulation of cytoplasmic lipid droplet in 3T3-L1 adipocytes

Cycloastragenol inhibits adipogenesis and fat accumulation in vitro and in vivo through activating Hedgehog signaling

In this study, we investigated the effect of cycloastragenol (CAG), a triterpenoid isolated from Astragalus membranaceus roots, on regulating the adipogenesis and fat accumulation in vitro and in vivo. During the adipogenesis of 3T3-L1 cells, CAG inhibited lipid accumulation and the expression of key adipogenic factors, proliferator-activated receptor γ (PPARγ) and CCAAT enhancer binding protein α (C/EBPα) and increased the expression of Gli1, a key mediator in Hedgehog (Hh) signaling. In HFD-induced animal experiment, CAG significantly reduced body weight gain without affecting brown fat weight. In addition, CAG regulated the expression of PPARγ, C/EBPα, and Gli1 in visceral white adipose tissue (vWAT). We also confirmed the inhibitory effect of CAG on specifically targeting white adipose tissue (WAT) formation in stromal vascular fraction (SVF) cell differentiation. Taken together, these results suggest that CAG may be a potent phytochemical preventing adipogenesis and obesity via Hh signaling.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01403-0.

Mechanism and Progress of Natural Products in the Treatment of NAFLD-Related Fibrosis

Nonalcoholic fatty liver disease (NAFLD) has emerged as the most prevalent chronic liver disorder worldwide, with liver fibrosis (LF) serving as a pivotal juncture in NAFLD progression. Natural products have demonstrated substantial antifibrotic properties, ushering in novel avenues for NAFLD treatment. This study provides a comprehensive review of the potential of natural products as antifibrotic agents, including flavonoids, polyphenol compounds, and terpenoids, with specific emphasis on the role of Baicalin in NAFLD-associated fibrosis. Mechanistically, these natural products have exhibited the capacity to target a multitude of signaling pathways, including Hedgehog, Wnt/β-catenin, TGF-β1, and NF-κB. Moreover, they can augment the activities of antioxidant enzymes, inhibit pro-fibrotic factors, and diminish fibrosis markers. In conclusion, this review underscores the considerable potential of natural products in addressing NAFLD-related liver fibrosis through multifaceted mechanisms. Nonetheless, it underscores the imperative need for further clinical investigation to authenticate their effectiveness, offering invaluable insights for future therapeutic advancements in this domain.

Atorvastatin reverses high cholesterol-induced cardiac remodelling and regulates mitochondrial quality-control in a cholesterol-independent manner: An experimental study

Mitochondria are key regulators of cell fate, maintaining self-stability by a fine-tuned quality-control network including mitophagy, biogenesis, fission and fusion processes. Myocardial mitochondria can be impaired by hypercholesterolemia. Statins, such as atorvastatin, are considered the cornerstone in the management of hypercholesterolaemia primarily due to their marked cholesterol-lowering ability. The direct effect of atorvastatin on myocardial mitochondria remains unclear. We aimed to explore whether atorvastatin could attenuate myocardial mitochondrial defects induced by high cholesterol, and whether cycloastragenol, a potent telomerase activator, could be used as a potential complementary bioactive compound for obesity and hypercholesterolaemia treatment. We found that atorvastatin at a low dose (3 mg/kg) did not reduce elevated serum cholesterol, but reversed cardiac remodelling and dysfunction in C57BL/6J mice fed with high-fat diet (HFD). Atorvastatin reversed the upregulated mitophagy, mitochondrial fission and fusion, accompanied by mitochondrial biogenesis activation in HFD-fed mice hearts. Mitochondrial structural impairments were attenuated by atorvastatin in HFD-fed mice and oxidized low-density lipoprotein (ox-LDL) exposed HL-1 cardiomyocytes. The depolarized mitochondrial membrane potential and increased mitochondrial oxygen consumption rates in ox-LDL exposed HL-1 cells were recovered by atorvastatin. Furthermore, atorvastatin co-treated with cycloastragenol had better effects on reducing body weight, improving cardiac remodelling and dysfunction, and protecting mitochondria in high cholesterol. Conclusively, low-dose atorvastatin exhibited a cholesterol-independent cardioprotective effect through improving the mitochondrial quality-control network and repairing mitochondrial ultrastructure in high cholesterol. Atorvastatin plus cycloastragenol supplement therapy has a better effect on treating obesity and hypercholesterolaemia.

Attenuation of obesity related inflammation in RAW 264.7 macrophages and 3T3-L1 adipocytes by varanadi kashayam and identification of potential bioactive molecules by UHPLC-Q-Orbitrap HRMS

Obesity is associated with chronic low-grade inflammation, characterised by the up-regulation of pro-inflammatory cytokines in obese adipose tissue. In this study, 3T3-L1 CM enhanced TNF-α and IL-1β in RAW 264.7 cells compared with LPS treated cells. However, treatment with Varanadi kashayam suppressed the inflammatory changes associated with RAW 264.7 cells. Subsequently, RAW CM used to stimulate adipocytes, resulting in decreased intracellular lipid content and reduced adipogenic markers after Varanadi kashayam treatment. The chemical profiling of Varanadi kashayam using UHPLC-Q-Orbitrap-HRMS identified 194 compounds by comparing their retention time, the experimentally measured exact mass of precursor, and fragmented ions, and fragmentation pattern with spectral library and reported literature. Collectively, Varanadi kashayam act as a potent anti-inflammatory and anti-adipogenic agent that could disrupt the crosstalk between adipocytes and macrophages. Hence it could be a better candidate for reducing inflammation associated with obese adipose tissue.

Molecular mechanism of down-regulating adipogenic transcription factors in 3T3-L1 adipocyte cells by bioactive anti-adipogenic compounds

Obesity is growing at an alarming rate, which is characterized by increased adipose tissue. It increases the probability of many health complications, such as diabetes, arthritis, cardiac disease, and cancer. In modern society, with a growing population of obese patients, several individuals have increased insulin resistance. Herbal medicines are known as the oldest method of health care treatment for obesity-related secondary health issues. Several traditional medicinal plants and their effective phytoconstituents have shown anti-diabetic and anti-adipogenic activity. Adipose tissue is a major site for lipid accumulation as well as the whole-body insulin sensitivity region. 3T3-L1 cell line model can achieve adipogenesis. Adipocyte characteristics features such as expression of adipocyte markers and aggregation of lipids are chemically induced in the 3T3-L1 fibroblast cell line. Differentiation of 3T3-L1 is an efficient and convenient way to obtain adipocyte like cells in experimental studies. Peroxisome proliferation activated receptor γ (PPARγ) and Cytosine-Cytosine-Adenosine-Adenosine-Thymidine/Enhancer-binding protein α (CCAAT/Enhancer-binding protein α or C/EBPα) are considered to be regulating adipogenesis at the early stage, while adiponectin and fatty acid synthase (FAS) is responsible for the mature adipocyte formation. Excess accumulation of these adipose tissues and lipids leads to obesity. Thus, investigating adipose tissue development and the underlying molecular mechanism is important in the therapeutical approach. This review describes the cellular mechanism of 3T3-L1 fibroblast cells on potential anti-adipogenic herbal bioactive compounds.

Terpenoids as Potential Geroprotectors

Terpenes and terpenoids are the largest groups of plant secondary metabolites. However, unlike polyphenols, they are rarely associated with geroprotective properties. Here we evaluated the conformity of the biological effects of terpenoids with the criteria of geroprotectors, including primary criteria (lifespan-extending effects in model organisms, improvement of aging biomarkers, low toxicity, minimal adverse effects, improvement of the quality of life) and secondary criteria (evolutionarily conserved mechanisms of action, reproducibility of the effects on different models, prevention of age-associated diseases, increasing of stress-resistance). The number of substances that demonstrate the greatest compliance with both primary and secondary criteria of geroprotectors were found among different classes of terpenoids. Thus, terpenoids are an underestimated source of potential geroprotectors that can effectively influence the mechanisms of aging and age-related diseases.

Cycloastragenol prevents age-related bone loss: Evidence in d-galactose-treated and aged rats

BACKGROUND AND AIMS

Aging-induced bone loss is a multifactorial, age-related, and progressive phenomenon among the general population and may further progress to osteoporosis and increase the risk of fractures. Cycloastragenol (CAG), currently the only compound reported that activates human telomerase, is thought to be able to alleviate or delay the symptoms of aging and chronic diseases. Previous research has suggested that CAG may have the potential to alleviate age-related bone loss. However, to date, no research has specifically focused on this aspect. In this study, we aimed to investigate whether CAG could prevent senile osteoporosis, and further reveal its underlying mechanism.

METHODS

CAG treatment was administrated into two bone loss rat models (D-galactose administration and aging) for 20 weeks and 33 weeks, respectively. Serum biomarkers analyses, bone biomechanical tests, micro-computed tomography assessment, and bone histomorphometry analyses were performed on the bone samples collected at the endpoint, to determine whether CAG could prevent or alleviate age-related bone loss. Proteomic analysis was performed to reveal the changes in protein profiles of the bones, and western blot was used to further verify the identity of the key proteins. The viability, osteoblastic differentiation, and mineralization of MC3T3-E1 cells were also evaluated after CAG treatment in vitro.

RESULTS

The results suggest that CAG treatment improves bone formation, reduces osteoclast number, alleviates the degradation of bone microstructure, and enhances bone biomechanical properties in both d-galactose- and aging-induced bone loss models. CAG treatment promotes viability, osteoblastic differentiation, and mineralization in MC3T3-E1 cells. Proteomic and western blot analyses revealed that CAG treatment increases osteoactivin (OA) expression to alleviate bone loss.

CONCLUSION

The results revealed that CAG alleviates age-related bone loss and improves bone microstructure and biomechanical properties. This may due to CAG-induced increase in OA expression. In addition, the results support preclinical investigations of CAG as a potential therapeutic medicine for the treatment of senile osteoporosis.

Exploring Molecular Mechanism of Huangqi in Treating Heart Failure Using Network Pharmacology

Heart failure (HF), a clinical syndrome with a high incidence due to various reasons, is the advanced stage of most cardiovascular diseases. Huangqi is an effective treatment for cardiovascular disease, which has multitarget, multipathway functions. Therefore, we used network pharmacology to explore the molecular mechanism of Huangqi in treating HF. In this study, 21 compounds of Huangqi, which involved 407 targets, were obtained and reconfirmed using TCMSP and PubChem databases. Moreover, we used Cytoscape 3.7.1 to construct compound-target network and screened the top 10 compounds. 378 targets related to HF were obtained from CTD and GeneCards databases and HF-target network was constructed by Cytoscape 3.7.1. The 46 overlapping targets of HF and Huangqi were gotten by Draw Venn Diagram. STRING database was used to set up a protein-protein interaction network, and MCODE module and the top 5 targets with the highest degree for overlapping targets were obtained. GO analysis performed by Metascape indicated that the overlapping targets were mainly enriched in blood vessel development, reactive oxygen species metabolic process, response to wounding, blood circulation, and so on. KEGG analysis analyzed by ClueGO revealed that overlapping targets were mainly enriched in AGE-RAGE signaling pathway in diabetic complications, IL-17 signaling pathway, HIF-1 signaling pathway, c-type lectin receptor signaling pathway, relaxin signaling pathway, and so on. Finally, molecular docking showed that top 10 compounds of Huangqi also had good binding activities to important targets compared with digoxin, which was carried out in CB-Dock molecular docking server. In conclusion, Huangqi has potential effect on regulating overlapping targets and GE-RAGE signaling pathway in diabetic complications, IL-17 signaling pathway, HIF-1 signaling pathway, and so on to be a latent multitarget, multipathway treatment for HF.

The protective effect of cycloastragenol on aging mouse circadian rhythmic disorder induced by d-galactose

Aging process in mammals is associated with a decline in amplitude and a long period of circadian behaviors which are regulated by a central circadian regulator in the suprachiasmatic nucleus (SCN) and local oscillators in peripheral tissues. It is unclear whether enhancing clock function can retard aging. Using fibroblasts expressing per2::lucSV and senescent cells, we revealed cycloastragenol (CAG), a natural aglycone derivative from astragaloside IV, as a clock amplitude enhancing small molecule. CAG could activate telomerase to antiaging, but no reports focused on its effects on circadian rhythm disorders in aging mice. Here we analyze the potential effects of CAG on d-galactose-induced aging mice on the circadian behavior and expression of clock genes. For this purpose, CAG (20 mg/kg orally), was administered daily to d-galactose (150 mg/kg, subcutaneous) mice model of aging for 6 weeks. An actogram analysis of free-running activity of these mice showed that CAG significantly enhances the locomotor activity. We further found that CAG increase expressions of per2 and bmal1 genes in liver and kidney of aging mouse. Furthermore, CAG enhanced clock protein BMAL1 and PER2 levels in aging mouse liver and SCN. Our results indicated that the CAG could restore the behavior of circadian rhythm in aging mice induced by d-galactose. These data of present study suggested that CAG could be used as a novel therapeutic strategy for the treatment of age-related circadian rhythm disruption.

Cycloastragenol: An exciting novel candidate for age-associated diseases

Cycloastragenol (CAG) is a triterpenoid saponin compound and a hydrolysis product of the main active ingredient in Astragalus membranaceus (Fisch.) Bunge. An increasing body of evidence has indicated that CAG has a wide spectrum of pharmacological functions, which are attracting attention in the research community. The aim of the present review paper was to review and elucidate the advanced study of CAG. The focus was on advanced studies of CAG in English and Chinese databases; the literature was collected and reviewed to summarize the latest efficacy, pharmacokinetics and adverse reactions of CAG. Extensive pharmacological effects have been attributed to CAG, including telomerase activation, telomere elongation, anti-inflammatory and anti-oxidative properties; CAG has also been reported to improve lipid metabolism. Clinical research has demonstrated that CAG activates telomerase in humans and ameliorates various biomarkers. CAG is absorbed through the intestinal epithelium via passive diffusion and undergoes first-pass hepatic metabolism. Within a certain dose range, oral CAG is relatively safe; however, underlying mechanisms associated with CAG are not clear, and thus, we should be aware of potential adverse reactions associated with CAG. According to existing studies and clinical trials, CAG is safe and has broad application prospects. However, further studies are required to fully understand its efficacy and potential adverse reactions, and to ensure the proper use of CAG is applied to treat diseases clinically.

Cycloastragenol improves hepatic steatosis by activating farnesoid X receptor signalling

Non-alcoholic fatty liver disease (NAFLD) has become a global health problem. However, there is no approved therapy for NAFLD. Farnesoid X receptor (FXR) is a potential drug target for treatment of NAFLD. In an attempt to screen FXR agonists, we found that cycloastragenol (CAG), a natural occurring compound in Astragali Radix, stimulated FXR transcription activity. In animal studies, we demonstrated that CAG treatment resulted in obvious reduction of high-fat diet induced lipid accumulation in liver accompanied by lowered blood glucose, serum triglyceride levels and hepatic bile acid pool size. The stimulation of FXR signalling by CAG treatment in DIO mice was confirmed via gene expression and western blot analysis. Molecular docking data further supported the interaction of CAG and FXR. In addition, CAG alleviated hepatic steatosis in methionine and choline deficient L-amino acid diet (MCD) induced non-alcoholic steatohepatitis (NASH) mice. Our data suggest that CAG ameliorates NAFLD via the enhancement of FXR signalling.

Calycosin attenuates triglyceride accumulation and hepatic fibrosis in murine model of non-alcoholic steatohepatitis via activating farnesoid X receptor

BACKGROUND

Non-alcoholic steatohepatitis (NASH) represents the more severe end of hepatic steatosis and is associated with progressive liver disease. Calycosin, derived from the root of Radix Astragali, has been demonstrated to have favorable efficacy on acute liver injury.

PURPOSE

The present study was to investigate the hepatoprotective effect of calycosin on attenuating triglyceride accumulation and hepatic fibrosis, as well as explore the potential mechanism in murine model of NASH.

STUDY DESIGN

The C57BL/6 male mice were fed with methionine choline deficient (MCD) diet for 4 weeks to induce NASH and treated with or without calycosin by oral gavage for 4 weeks.

METHODS

The body weight, liver weight and the liver to body weight ratios were measured. Serum ALT, AST, TG, TC, FFA, MCP-1 and mKC levels were accessed by biochemical methods. H&E staining and Oil red O staining were used to identify the amelioration of liver histopathology. Immunohistochemistry of a-SMA, Masson trichrome staining and Sirius red staining were used to identify the amelioration of hepatic fibrosis. The quantitative real-time-PCR and Western blot were applied to observe the expression changes of key factors involved in triglyceride synthesis, free fatty acid β-oxidation and hepatic fibrosis.

RESULTS

Calycosin significantly inhibited body weight loss induced by MCD diet, decreased the ALT and AST activities, MCP-1 and mKC in a dose-dependent manner. The H&E and Oil red O staining indicated calycosin effectively improved hepatic steatosis, improved the degree of triglyceride accumulation. Masson trichrome and Sirius red staining indicated that calycosin treatment remarkably attenuated the degree of hepatic fibrosis. Immunohistochemistry of a-SMA demonstrated that calycosin attenuated hepatic fibrosis by inhibiting hepatic stellate cell activation. Further, calycosin inhibited the expression of SREBP-1c, FASN, ACC and SCD1 involved in triglyceride synthesis, promoted the expression of PPARa, CPT1, Syndecan-1 and LPL involved in free fatty acid β-oxidation. The above effects of calycosin were attributed to FXR activation.

CONCLUSION

Calycosin attenuates triglyceride accumulation and hepatic fibrosis to protect against NASH via FXR activation.

Target molecules in 3T3-L1 adipocytes differentiation are regulated by maslinic acid, a natural triterpene from Olea europaea

BACKGROUND

Metabolic syndrome is a set of pathologies among which stand out the obesity, which is related to the lipid droplet accumulation and changes to cellular morphology regulated by several molecules and transcription factors. Maslinic acid (MA) is a natural product with demonstrated pharmacological functions including anti-inflammation, anti-tumor and anti-oxidation, among others.

PURPOSE

Here we report the effects of MA on the adipogenesis process in 3T3-L1 cells.

METHODS

Cell viability, glucose uptake, cytoplasmic triglyceride droplets, triglycerides quantification, gene transcription factors such as peroxisome proliferator-activated receptor γ (PPARγ) and adipocyte fatty acid-binding protein (aP2) and intracellular Ca²⁺ levels were determined in pre-adipocytes and adipocytes of 3T3-L1 cells.

RESULTS

MA increased glucose uptake. MA also decreased lipid droplets and triglyceride levels, which is in concordance with the down-regulation of PPARγ and aP2. Finally, MA increased the intracellular Ca²⁺ concentration, which could also be involved in the demonstrated antiadipogenic effect of this triterpene.

CONCLUSION

MA has been demonstrated as potential antiadipogenic compound in 3T3-L1 cells.

Agrimol B suppresses adipogenesis through modulation of SIRT1-PPAR gamma signal pathway

Studies of human genetics have implicated the role of SIRT1 in regulating obesity, insulin resistance, and longevity. These researches motivated the identification of novel SIRT1 activators. The current study aimed to investigate the potential efficacy of agrimol B, a polyphenol derived from Agrimonia pilosa Ledeb., on mediating SIRT1 activity and fat metabolism. Results showed that agrimol B significantly induced cytoplasm-to-nucleus shuttle of SIRT1. Furthermore, we confirmed that agrimol B dramatically inhibited 3T3-L1 adipocyte differentiation by reducing PPARγ, C/EBPα, FAS, UCP-1, and apoE expression. Consequently, adipogenesis was blocked by treatment of agrimol B at the early stage of differentiation in a dose-dependent manner, the IC50 value was determined as 3.35 ± 0.32 μM. Taken together, our data suggest a therapeutic potential of agrimol B on alleviating obesity, through modulation of SIRT1-PPARγ signal pathway.

Herbal Acupuncture for the Treatment of Obesity

Obesity is the state of excessive body fat accumulation and is mainly caused by consuming more calories than are burned through physical activity. Herbal acupuncture (HA), also known as pharmacopuncture, has been increasingly used in clinics of Korean medical to alleviate obesity. This review analyzed four clinical studies and 16 animal studies on the effectiveness of HA as a treatment for obesity. Clinical evidence suggests that various kinds of HA might be beneficial for treating obesity; however, further investigations with well-designed, evidence-based, randomized clinical trials are needed. Animal studies support the idea that HA might be beneficial for the treatment of obesity and provide possible mechanisms, such as anti-inflammation, antioxidation, modulating lipid metabolism and so on, to explain the effect of HA on obesity. This review, based on the evidence collected, suggests that HA could have a beneficial effect for alleviating obesity by modulating inflammation, oxidative stress, lipid metabolism, leptin, and the insulin signal.

Disposition of Astragaloside IV via Enterohepatic Circulation Is Affected by the Activity of the Intestinal Microbiome

Astragaloside IV (ASIV) is a typical bioactive constituent of Radix Astragali. The study aimed to investigate the enterohepatic circulation of ASIV and evaluate the impact of activity of intestinal microbiota on the deposition of ASIV. The amounts of ASIV and its metabolites were quantified by an LC-MS/MS method. ASIV was metabolized by intestinal bacteria to form brachyoside B (Bra B), cyclogaleginoside B (Cyc B), cycloastragenol (CA), iso-cycloastragenol (iso-CA), and dehydrogenated metabolite of CA (CA-2H). CA and iso-CA circulated in blood besides ASIV when rats received ASIV intragastrically or intravenously. After rats were intragastrically administered 10 mg/kg ASIV, the AUC0-t values of ASIV, CA, and iso-CA were 109 ± 55, 26.8 ± 17.9, and 77.9 ± 35.1 nM·h, respectively. The plasma distribution of ASIV was significantly affected by bile duct drainage when ASIV was administered through the duodenum. ASIV, Bra B, and Cyc B were secreted from bile after duodenal administration of ASIV. Antibiotics markedly inhibited the metabolism of ASIV in intestinal microbiota. After rats were pretreated with antibiotics, the AUC0-t of iso-CA was 4.8 times less than that in control rats and the concentration of CA became undetectable. Variations in intestinal microbiota may change the disposition of ASIV and subsequently influence its potential health benefits.

Calycosin orchestrates the functions of Danggui Buxue Tang, a Chinese herbal decoction composing of Astragali Radix and Angelica Sinensis Radix: An evaluation by using calycosin-knock out herbal extract

ETHNOPHARMACOLOGICAL RELEVANCE

Danggui Buxue Tang (DBT) is a classical Chinese herbal decoction containing two herbs, Astragali Radix (AR) and Angelicae Sinensis Radix (ASR), which serves as dietary supplement for treating women menopausal syndromes. Pharmacological studies indicate that DBT has estrogenic, erythropoietic and osteogenic properties; however, the action mechanism for this complex herbal decoction is not known. Calycosin, a major flavonoid in AR, shares similar structure with β-estradiol, and thus which is hypothesized to be the critical compound of DBT. Here, we aim to investigate the role of calycosin in DBT in terms of its biological functions by using a calycosin-depleted DBT decoction (DBT(Δcal)). The biological functions of DBT(Δcal) and parental DBT were systematically compared.

MATERIALS AND METHODS

In order to standardize DBT decoction, four chemical markers were determined and quantified by HPLC. A semi-preparative HPLC method was utilized to prepare DBT(Δcal). The authenticity of DBT(Δcal) was evaluated by LC-QQQ-MS/MS. To reveal the effect of calycosin on DBT functions, several cell assays related to the known properties of DBT were revealed, including estrogenic, erythropoietic and osteogenic functions.

RESULTS

As compared to parental DBT, the estrogenic, erythropoietic and osteogenic abilities were markedly reduced in DBT(Δcal). However, calycosin alone did not show significant responses.

CONCLUSIONS

Our results suggest that calycosin is a bioactive chemical in DBT decoction, and which could play a key linker in orchestrating multi-components of DBT as to achieve maximal functions. These discoveries should be invaluable in drug development and in investigating the modernization of traditional Chinese medicine from a new perspective.