Salidroside attenuates LPS-induced pro-inflammatory cytokine responses and improves survival in murine endotoxemia

Elucidating the role of Rhodiola rosea L. in sepsis-induced acute lung injury via network pharmacology: emphasis on inflammatory response, oxidative stress, and the PI3K-AKT pathway

CONTEXT

Sepsis-induced acute lung injury (ALI) is associated with high morbidity and mortality. Rhodiola rosea L. (Crassulaceae) (RR) and its extracts have shown anti-inflammatory, antioxidant, immunomodulatory, and lung-protective effects.

OBJECTIVE

This study elucidates the molecular mechanisms of RR against sepsis-induced ALI.

MATERIALS AND METHODS

The pivotal targets of RR against sepsis-induced ALI and underlying mechanisms were revealed by network pharmacology and molecular docking. Human umbilical vein endothelial cells (HUVECs) were stimulated by 1 μg/mL lipopolysaccharide for 0.5 h and treated with 6.3, 12.5, 25, 50, 100, and 200 μg/mL RR for 24 h. Then, the lipopolysaccharide-stimulated HUVECs were subjected to cell counting kit-8 (CCK-8), enzyme-linked immunosorbent, apoptosis, and Western blot analyses. C57BL/6 mice were divided into sham, model, low-dose (40 mg/kg), mid-dose (80 mg/kg), and high-dose (160 mg/kg) RR groups. The mouse model was constructed through caecal ligation and puncture, and histological, apoptosis, and Western blot analyses were performed for further validation.

RESULTS

We identified six hub targets (MPO, HRAS, PPARG, FGF2, JUN, and IL6), and the PI3K-AKT pathway was the core pathway. CCK-8 assays showed that RR promoted the viability of the lipopolysaccharide-stimulated HUVECs [median effective dose (ED50) = 18.98 μg/mL]. Furthermore, RR inhibited inflammation, oxidative stress, cell apoptosis, and PI3K-AKT activation in lipopolysaccharide-stimulated HUVECs and ALI mice, which was consistent with the network pharmacology results.

DISCUSSION AND CONCLUSION

This study provides foundational knowledge of the effective components, potential targets, and molecular mechanisms of RR against ALI, which could be critical for developing targeted therapeutic strategies for sepsis-induced ALI.

Salidroside Ameliorates Ischemia/Reperfusion-Induced Human Cardiomyocyte Injury by Inhibiting the Circ_0097682/miR-671-5p/USP46 Pathway

Salidroside shows an inhibitory effect on myocardial ischemia/reperfusion (I/R) injury; however, the underlying mechanism remains to be explored. The present work analyzes the mechanism that drives salidroside to ameliorate I/R-induced human cardiomyocyte injury. Human cardiomyocytes were subjected to I/R treatment to simulate a myocardial infarction cell model. Cell viability, cell proliferation, and cell apoptosis were analyzed by CCK-8 assay, EdU assay, and flow cytometry analysis, respectively. RNA expression levels of circ_0097682, miR-671-5p, and F-box and ubiquitin-specific peptidase 46 (USP46) were detected by qRT-PCR. Protein expression was measured by Western blotting assay. The levels of IL-6, IL-1β, and TNF-α in cell supernatant were detected by enzyme-linked immunosorbent assays. Salidroside treatment relieved I/R-induced inhibitory effect on AC16 cell proliferation and promoting effects on cell apoptosis, inflammation, and oxidative stress. Salidroside inhibited circ_0097682 expression in I/R-treated AC16 cells. Salidroside-mediated inhibition of I/R-induced cell injury involved the downregulation of circ_0097682 expression. In addition, circ_0097682 bound to miR-671-5p in AC16 cells, and miR-671-5p inhibitors rescued salidroside pretreatment-mediated effects in I/R-treated AC16 cells. Moreover, miR-671-5p targeted USP46 in AC16 cells, and USP46 introduction partially relieved circ_0097682 depletion or salidroside pretreatment-induced effects in I/R-treated AC16 cells. Salidroside ameliorated I/R-induced AC16 cell injury by inhibiting the circ_0097682/miR-671-5p/USP46 pathway.

Study of Salidroside and Its Inflammation Targeting Emulsion Gel for Wound Repair

Salidroside has been widely used in anti-tumor, cardiovascular, and cerebrovascular protection. However, there are few reports of its use for wound repair. Herein, salidroside inflammation-targeted emulsion gel and non-targeted emulsion gel were developed for wound repair. The inflammation-targeted emulsion gels showed an overall trend of better transdermal penetration and lower potential than non-targeted emulsion gels (-58.7 mV and -1.6 mV, respectively). The apparent improvement of the trauma surface was significant in each administration group. There was a significant difference in the rate of wound healing of the rats between each administration group and the model group at days 7 and 14. Pathological tissue sections showed that inflammatory cells in the epidermis, dermis, and basal layer were significantly reduced, and the granulation tissue was proliferated in the inflammation-targeted emulsion gel group and the non-targeted emulsion gel group. Regarding the expressions of EGF and bFGF, the expressions of bFGF and EGF in the tissues of the inflammation-targeted group at days 7, 14, or 21 were significantly higher than that of the non-targeted emulsion gel group and the model group, both of which were statistically significant compared with the model group (p < 0.05). These results demonstrated that salidroside has the potential as an alternative drug for wound repair.

Phytochemical profile and anti-inflammatory activity of a commercially available Rhodiola rosea root extract

Rhodiola rosea roots and rhizomes hold an important place in the folk medicines of Russia, Scandinavia, Mongolia, and China as a health supplement for stimulating the nervous system, enhancing physical and mental performances, and nowadays they constitute the active ingredient in many popular commercial preparations sold worldwide as food additives, pharmaceutical remedies, and drinks. This study was aimed at providing a detailed phytochemical characterization of the Rhodiola 5%, a commercially available extract of R. rosea roots, and resulted in the characterization of 18 secondary metabolites, including 13 polyphenols and 6 terpenoids, and in the discovery of the new rhodiosidin (5), the first R. rosea metabolite to show both terpenoid and cinnamoyl moieties. The 5-lipoxygenase inhibiting activity of the main components was characterized and disclosed that rosiridin (6), kenposide A and rosavins are mainly responsible for this activity of the extract.

Mechanism and Experimental Verification of the Use of Rhodiola crenulata to Cytokine Storm Based on Network Pharmacology and Molecular Docking

Objective: To identify the potential biological mechanisms by which Rhodiola crenulata (RC) treats cytokine storm (CS) using network pharmacology, molecular docking, and experimental verification. Methods: The ingredients and targets of RC were collected from the Organchem database. CS-related genes were collected using the GeneCards and OMIM databases. Cytoscape 3.7.2 software was used to construct the RC-CS network diagram. These data were inputted into the STRING database to construct a protein–protein interaction network. we performed gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes enrichment analysis using DAVID and R software. Molecular docking of the active ingredient and pathway-related targets was carried out using AutoDock Vina and PyMOL, and then a CS model was established in rats induced by lipopolysaccharide for in vivo experimental verification. Results: The network pharmacology results showed that kaempferol was the most important active component of RC in the treatment of CS, and IL6 and STAT3 were identified as key targets. Molecular docking results showed that RC active components kaempferol had a good binding ability to IL6/STAT3. At the same time, compared with the model group, different doses of kaempferol could down-regulate the expression of inflammatory factors ( P < .05), and protect against systemic inflammatory response multiple organ damage. Conclusion: This study preliminarily revealed that RC can prevent and treat CS by regulating the expression of inflammatory factors, inhibiting the systemic inflammatory response induced by lipopolysaccharide, and providing a theoretical basis for the study of its pharmacodynamic material basis and mechanism of action.

Tibetan medicine salidroside improves host anti-mycobacterial response by boosting inflammatory cytokine production in zebrafish

The treatment for tuberculosis (TB), especially multidrug-resistant TB (MDR-TB), has a prolonged cycle which can last up to a year. This is partially due to the lack of effective therapies. The development of novel anti-TB drugs from the perspective of host immune regulation can provide an important supplement for conventional treatment strategies. Salidroside (SAL), a bioactive component from the Tibetan medicine Rhodiola rosea, has been used in the treatment of TB, although its mechanism remains unclear. Here, the bacteriostatic effect of SAL in vivo was first demonstrated using a zebrafish–M. marinum infection model. To further investigate the underlying mechanism, we then examined the impact of SAL on immune cell recruitment during wound and infection. Increased macrophage and neutrophil infiltrations were found both in the vicinity of the wound and infection sites after SAL treatment compared with control, which might be due to the elevated chemokine expression levels after SAL treatment. SAL treatment alone was also demonstrated to improve the survival of infected zebrafish larvae, an effect that was amplified when combining SAL treatment with isoniazid or rifampicin. Interestingly, the reduced bacterial burden and improved survival rate under SAL treatment were compromised in tnfα-deficient embryos which suggests a requirement of Tnfα signaling on the anti-mycobacterial effects of SAL. In summary, this study provides not only the cellular and molecular mechanisms for the host anti-mycobacterial effects of the Tibetan medicine SAL but also proof of concept that combined application of SAL with traditional first-line anti-TB drugs could be a novel strategy to improve treatment efficacy.

Salidroside ameliorates orthopedic surgery-induced cognitive dysfunction by activating adenosine 5'-monophosphate-activated protein kinase signaling in mice

Perioperative neurocognitive disorders (PND) are the most common postoperative complications with few therapeutic options. Salidroside, a plant-derived compound, has gained increased attention as a treatment for various neurological diseases and particularly as a modifier of microglia-mediated neuroinflammation. However, the effect of salidroside on orthopedic surgery-induced cognitive dysfunction and the underlying mechanisms are largely unknown. Here, we found that salidroside greatly attenuated cognitive impairment in mice after orthopedic surgery. Neuroinflammation in the mouse hippocampus was also attenuated by salidroside. Meanwhile, salidroside treatment induced a switch in microglial polarization to the anti-inflammatory phenotype. In vitro, salidroside suppressed the expression of proinflammatory cytokines and induced a switch in microglial phenotype to the anti-inflammatory phenotype. Mechanistically, molecular docking studies revealed the potential AMPK activation activity of salidroside. And salidroside did up-regulated the AMPK pathway proteins. Moreover, AMPK antagonist abolished the effects of salidroside in vivo and in vitro. Taken together, our results demonstrated that salidroside effectively suppressed PND by suppressing microglia-mediated neuroinflammation through activating AMPK pathway, and it might be a novel therapeutic approach for PND.

Dietary Supplementation of Salidroside Alleviates Liver Lipid Metabolism Disorder and Inflammatory Response to Promote Hepatocyte Regeneration via PI3K/AKT/Gsk3-β Pathway

Fatty liver hemorrhagic syndrome (FLHS) is a chronic hepatic disease which occurs when there is a disorder in lipid metabolism. FLHS is often observed in caged laying hens and characterized by a decrease in egg production and dramatic increase of mortality. Salidroside (SDS) is an herbal drug which has shown numerous pharmacological activities, such as protecting mitochondrial function, attenuating cell apoptosis and inflammation, and promoting antioxidant defense system. We aimed to determine the therapeutic effects of SDS on FLHS in laying hens and investigate the underlying mechanisms through which SDS operates these functions. We constructed oleic acid (OA)-induced fatty liver model in vitro and high-fat diet-induced FLHS of laying hens in vivo. The results indicated that SDS inhibited OA-induced lipid accumulation in chicken primary hepatocytes, increased hepatocyte activity, elevated the mRNA expression of proliferation related genes PCNA, CDK2, and cyclinD1 and increased the protein levels of PCNA and CDK2 (P < 0.05), as well as decreased the cleavage levels of Caspase-9, Caspase-8, and Caspase-3 and apoptosis in hepatocytes (P < 0.05). Moreover, SDS promoted the phosphorylation levels of PDK1, AKT, and Gsk3-β, while inhibited the PI3K inhibitor (P < 0.05). Additionally, we found that high-fat diet-induced FLHS hens had heavier body weight, liver weight, and abdominal fat weight, and severe steatosis in histology, compared with the control group (Con). However, hens fed with SDS maintained lighter body weight, liver weight, and abdominal fat weight, as well as normal liver without hepatic steatosis. In addition, high-fat diet-induced FLHS hens had high levels of serum total cholesterol (TC), triglyceride (TG), alanine transaminase (ALT), and aspartate aminotransferase (AST) compared to the Con group, however, in the Model+SDS group, the levels of TC, TG, ALT, and AST decreased significantly, whereas the level of superoxide dismutase (SOD) increased significantly (P < 0.05). We also found that SDS significantly decreased the mRNA expression abundance of PPARγ, SCD, and FAS in the liver, as well as increased levels of PPARα and MTTP, and decreased the mRNA expression of TNF-α, IL-1β, IL-6, and IL-8 in the Model+SDS group (P < 0.05). In summary, this study showed that 0.3 mg/mL SDS attenuated ROS generation, inhibited lipid accumulation and hepatocyte apoptosis, and promoted hepatocyte proliferation by targeting the PI3K/AKT/Gsk3-β pathway in OA-induced fatty liver model in vitro, and 20 mg/kg SDS alleviated high-fat-diet-induced hepatic steatosis, oxidative stress, and inflammatory response in laying hens in vivo.

Salidroside attenuates cardiac dysfunction in a rat model of diabetes

AIM

This study aimed to investigate the therapeutic effects of salidroside on diabetes-induced cardiovascular disease.

METHODS

Sprague-Dawley rats treated with 65 mg/kg of streptozotocin (STZ) on a daily basis were used to establish the diabetic rat model (blood glucose levels >13.9 mmol/L). Cardiac functions of diabetic rats were evaluated by their haemodynamic alterations. Western blot assay was performed to evaluate the protein levels of multiple signalling pathway factors. Quantitative real-time PCR assay was performed to investigate the inflammation and oxidative stress of diabetic rats.

RESULTS

Salidroside treatment improved the cardiac functions of diabetic rats. In addition, salidroside therapy attenuated the cardiac oxidative stress induced by diabetes. Salidroside inhibited the diabetes-induced inflammation in diabetic rat hearts. The apoptosis of cardiomyocytes was also alleviated by the treatment of salidroside. Salidroside also upregulated the phosphorylation levels of AMPK, ACC, TSC2 and RAPTOR.

CONCLUSION

Salidroside exerts protective effects against diabetes-induced cardiac dysfunction by modulating the mTOR and AMPK signalling pathways.

Protective Effect of Topiroxostat on Myocardial Injury Induced by Lipopolysaccharide

BACKGROUND

Myocardial injury induced by sepsis is the most common cause of death. Topiroxostat has been found to have organ protective effects, but its role in septic shock-related cardiomyocyte damage is still unclear and needs further study.

MATERIAL AND METHODS

An endotoxemic shock model in rats was constructed. After topiroxostat treatment, hemodynamic parameters, myocardial injury marker enzymes, oxidative stress, myocardial injury, and apoptosis were measured by polyphysiograph, enzyme-linked immunosorbent assay, hematoxylin and eosin staining, TUNEL staining, and western blot. During in vitro experiments, the effect of topiroxostat on cell vitality, oxidative stress, inflammatory factors, apoptosis-related markers, phosphorylated-p65 (p-p65) and p65 expressions were measured by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), flow cytometry, enzyme-linked immunosorbent assay, quantitative real-time polymerase chain reaction, and western blot.

RESULTS

Topiroxostat improved myocardial dysfunction and superoxide dismutase activity while suppressing levels of creatine kinase, lactate dehydrogenase and malondialdehyde in serum of endotoxemic shock rats. Additionally, topiroxostat augmented dry-wet weight ratios of the hearts in rats. Meanwhile, topiroxostat was proved to alleviate interstitial edema and apoptosis in myocardial tissues of endotoxemic shock rats. During in vitro experiments, topiroxostat pretreatment elevated lipopolysaccharide (LPS)-induced H9c2 cell vitality, and alleviated oxidative stress and inflammation. Moreover, topiroxostat pretreatment downregulated apoptosis-related markers, p-p65, and p-p65/p65 levels in LPS-induced H9c2 cells.

CONCLUSIONS

Topiroxostat attenuated LPS-induced myocardial injury via repressing apoptosis and oxidative stress.

Anti-Apoptotic Role of Sanhuang Xiexin Decoction and Anisodamine in Endotoxemia

Endotoxemia is characterized by initial uncontrollable inflammation, terminal immune paralysis, significant cell apoptosis and tissue injury, which can aggravate or induce multiple diseases and become one of the complications of many diseases. Therefore, anti-inflammatory and anti-apoptotic therapy is a valuable strategy for the treatment of endotoxemia-induced tissue injury. Traditional Chinese medicine exhibits great advantages in the treatment of endotoxemia. In this review, we have analyzed and summarized the active ingredients and their metabolites of Sanhuang Xiexin Decoction, a famous formula in endotoxemia therapy. We then have summarized the mechanisms of Sanhuang Xiexin Decoction against endotoxemia and its mediated tissue injury. Furthermore, silico strategy was used to evaluate the anti-apoptotic mechanism of anisodamine, a well-known natural product that widely used to improve survival in patients with septic shock. Finally, we also have summarized other anti-apoptotic natural products as well as their therapeutic effects on endotoxemia and its mediated tissue injury.

Salidroside: A review of its recent advances in synthetic pathways and pharmacological properties

Salidroside has been identified as one of the most potent compounds isolated from various Rhodiola plants, which have been used for a long time as adaptogens in traditional Chinese medicine. However, due to the severe growing environment of herbal medicine and large-scale excavation, the content of natural salidroside is extremely small. Most of the previous studies focused on herbal medicine, and there were few reviews on the synthesis of its main active ingredient salidroside. This paper presents different synthetic routes of salidroside to resolve the contradiction between supply and demand and lays the foundation for new drug research and development. Furthermore, emerging evidence indicates that salidroside, a promising environmentally-adapted drug with low toxicity and few side effects, possesses a wide spectrum of pharmacological properties, including activities on the cardiovascular system and central nervous system, anti-hypoxia, anti-fatigue and anti-aging activities, anticancer activity, anti-inflammatory activity, antioxidant activity, antivirus and immune stimulation activities, antidiabetic activity, anti-osteoporotic activity, and so on. Although the former researches have summarized the pharmacological effects of salidroside, focusing on the central nervous system, diabetes, and cancer, the overall pharmacological aspects of it have not been analyzed. This review highlights biological characteristics and mechanisms of action from 2009 to now as well as toxicological and pharmacokinetic data of the analyzed compound reported so far, with a view to providing a reference for further development and utilization of salidroside.

Salidroside regulates inflammatory pathway of alveolar macrophages by influencing the secretion of miRNA-146a exosomes by lung epithelial cells

The purpose of this study was to explore the investigative mechanism of salidroside (SAL) on LPS-induced acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). The exosomes from RLE-6TN are extracted and identified by transmission electron microscopy, particle size analysis and protein marker detection, and co-cultured with NR8383 cells. The ALI/ARDS model of SD rats was established by LPS (10 mg/kg) intratracheal instillation. Following a four-hour intratracheal instillation of LPS, 50 μl of RLE-6TN exosomes were injected through the tail vein. After that, SAL and miR-146a antagomir were injected into the tail vein for 72 h, respectively. As the changes of HE stain, body weight and ALI score are observed. The expression of miR-146a, TLR4, NF-kB, IRAK1, TRAF6 and their related proteins were detected by RT-PCR and Western blot, respectively. TNF-α, IL-6, IL-8 and IL-1 β inflammatory factors were detected by ELISA. The expression of miR-146a, NF-kB, IRAK, TRAF6 and related inflammatory factors in LPS-induced NR8383 was significantly higher than that in the control group, while SAL has greatly reduced the expression of TLR4 mediated NF-kB inflammatory pathway and related inflammatory factors. SAL can significantly improve the LPS-induced lung morphological abnormalities, slowed down the rate of weight loss in rats, and reducing the ALI score. The expression trend of NF-kB, IRAK, TRAF6 and related inflammatory factors in rats’ lung tissues was consistent with that in NR8383 cells. SAL has a protective effect on ALI/ARDS caused by sepsis, which is likely to be developed to a potential treatment for the disease. To sum up, this study provides a new theoretical basis for the treatment of ALI/ARDS with SAL.

Transrutinosylation of tyrosol by flower buds of Sophora japonica

Dried flower buds of Japanese sophora (Sophora japonica) comprising rutinosidase activity were tested in rutinosylation of tyrosol via transglycosylation process from rutin. Optimal conditions for transrutinosylation of tyrosol were 49 mM rutin and 290 mM tyrosol, giving maximum conversion up to 66.4% and 24% yield of isolated and purified rutinoside. The rutinosylation proceeded exclusively on the primary hydroxyl of tyrosol, thus forming rhamnosylated derivative of salidroside. This strict regioselectivity differentiates the sophora biocatalyst from microbial rutinosidases.

Medicinal Plants and Phytochemicals for the Treatment of Pulmonary Hypertension

Background

Pulmonary hypertension (PH) is a progressive disease that is associated with pulmonary arteries remodeling, right ventricle hypertrophy, right ventricular failure and finally death. The present study aims to review the medicinal plants and phytochemicals used for PH treatment in the period of 1994 – 2019.

Methods

PubMed, Cochrane and Scopus were searched based on pulmonary hypertension, plant and phytochemical keywords from August 23, 2019. All articles that matched the study based on title and abstract were collected, non-English, repetitive and review studies were excluded.

Results

Finally 41 studies remained from a total of 1290. The results show that many chemical treatments considered to this disease are ineffective in the long period because they have a controlling role, not a therapeutic one. On the other hand, plants and phytochemicals could be more effective due to their action on many mechanisms that cause the progression of PH.

Conclusion

Studies have shown that herbs and phytochemicals used to treat PH do their effects from six mechanisms. These mechanisms include antiproliferative, antioxidant, antivascular remodeling, anti-inflammatory, vasodilatory and apoptosis inducing actions. According to the present study, many of these medicinal plants and phytochemicals can have effects that are more therapeutic than chemical drugs if used appropriately.

Interfacial Nanoinjection-Based Nanoliter Single-Cell Analysis

Single-cell analysis offers unprecedented resolution for the investigation of cellular heterogeneity and the capture of rare cells from large populations. Here, described is a simple method named interfacial nanoinjection (INJ), which can miniaturize various single-cell assays to be performed in nanoliter water-in-oil droplets on standard microwell plates. The INJ droplet handler can adjust droplet volumes for multistep reactions on demand with high precision and excellent monodispersity, and consequently enables a wide range of single-cell assays. Importantly, INJ can be coupled with fluorescence-activated cell sorting (FACS), which is currently the most effective and accurate single-cell sorting and isolation method. FACS-INJ pipelines for high-throughput plate well-based single-cell analyses, including single-cell proliferation, drug-resistance testing, polymerase chain reaction (PCR), reverse-transcription PCR, and whole-genome sequencing are introduced. This FACS-INJ pipeline is compatible with a wide range of samples and can be extended to various single-cell analysis applications in microbiology, cell biology, and biomedical diagnostics.

Protective effects of Salidroside on cardiac function in mice with myocardial infarction

Salidroside (SAL) is the major ingredient of Rhodiola rosea, and has been traditionally used in Chinese medicine for decades. Numerous studies have demonstrated the protective effects of SAL for myocardial ischemia. However, it is yet to be deciphered whether SAL has cardioprotective effects after myocardial infarction (MI) in vivo. In the present study, we established a mouse MI model via coronary artery ligation. The aim was to investigate whether SAL treatment could reduce mortality, improve cardiac function and attenuate myocardial remodeling in MI mice. Post-surgery, mice were randomly administered SAL or normal saline. After 21 days, SAL was found to significantly reduce mortality, improve cardiac function, reduce fibrosis and infarct size compared to normal saline. In addition, oral administration of SAL could attenuate myocardial inflammation and apoptosis and promote angiogenesis. SAL down-regulated the expression levels of TNF-α, TGF-β1, IL-1β, Bax and up-regulate the expression of Bcl-2, VEGF, Akt and eNOS. These results indicated that SAL could alleviate the pathological processes of myocardial remodeling in MI mice, and may be a potentially effective therapeutic approach for the management of clinical ischemic cardiovascular diseases.

Anti-gastric cancer effect of Salidroside through elevating miR-99a expression

Salidroside is an active ingredient extracted from Rhodiola rosea that has anti-tumor activities. The current paper attempted to assess the impact of Salidroside on gastric cancer (GC) and explore the potential mechanism. GC cell lines (SNU-216 and MGC803) and gastric epithelial cell line GES-1 were treated with Salidroside. CCK-8 assay, colony formation assay, flow cytometry and Transwell assay were respectively performed to evaluate GC cells phenotype. qRT-PCR and western blot were conducted to reveal the downstream genes and signaling of Salidroside. We found that 800 μM Salidroside was capable of reducing GC cells viability, while has no such impacts on GES-1 cells. Salidroside inhibited GC cells proliferation, migration, invasion and promoted apoptosis, which coupled with the down-regulation of p21, Bcl-2, MMP2, RhoA, p-ROCK1, Vimentin and the up-regulations of CyclinD1, Bax, cleaved caspases. miR-99a was found to be highly expressed in response to Salidroside treatment. Besides, the inhibition of MAPK/ERK and PI3K/AKT signaling induced by Salidroside was attenuated by miR-99a silence and in this process, IGF1R worked as a target of miR-99a. The anti-GC effect of Salidroside was also confirmed in a mouse model of GC. The promoting effect of Salidroside on miR-99a expression was also verified in vivo. Furthermore, Salidroside promoted the cisplatin-sensitivity of SGC7901/DDP cells. In conclusion, this study demonstrated that Salidroside possessed anti-GC effects through regulating miR-99a/IGF1R axis and inhibiting MAPK/ERK and PI3K/AKT pathways.

Anti-inflammatory effects of Rhodiola rosea L.: A review

Rhodiola rosea L., a worldwide botanical adaptogen, has been confirmed to possess protective effects of inflammatory injury for many diseases, including cardiovascular diseases, neurodegenerative diseases, diabetes, sepsis, and cancer. This paper is to review the recent clinical and experimental researches about the anti-inflammatory effects and the related mechanisms of Rhodiola rosea L. extracts, preparations, and the active compounds. From the collected information reviewed, this paper will provide the theoretical basis for its clinical application, and provide the evidences or guidance for future studies and medicinal exploitations of Rhodiola rosea L.

Salidroside prevents tumor necrosis factor-α-induced vascular inflammation by blocking mitogen-activated protein kinase and NF-κB signaling activation

Vascular inflammation is a key factor in the pathogenesis of atherosclerosis. Salidroside is an important active ingredient extracted from the root of the Rhodiola rosea plant, which has been reported to have antioxidative, anti-cancer, neuroprotective and cardioprotective effects. However, the effects of salidroside on vascular inflammation have not been clarified. The purpose of the present study was to investigate the protective effects of salidroside against tumor necrosis factor (TNF)-α-induced vascular inflammation in cardiac microvascular endothelial cells (CMECs), a specific cell type derived from coronary micro-vessels. Over a 24-h period, salidroside did not exert any significant cytotoxicity up to a dose of 100 µM. Additionally, salidroside decreased the expression levels of the cell adhesion molecule vascular cell adhesion molecule-1 (VCAM-1) in TNF-α-stimulated CMECs, thus suppressing monocyte-to-CMEC adhesion. Salidroside also decreased the production of inflammatory cytokines such as interleukin (IL)-1β, IL-6 and monocyte chemotactic protein 1 (MCP-1) in TNF-α-induced CMECs, as well as suppressing TNF-α-activated mitogen-activated protein kinase (MAPK) and NF-κB activation. Since MAPKs and NF-κB both serve notable roles in regulating the expression of VCAM-1, IL-1β, IL-6 and MCP-1, the present study provided a preliminary understanding of the mechanism underlying the protective effects of salidroside. Overall, salidroside alleviated vascular inflammation by mediating MAPK and NF-κB activation in TNF-α-induced CMECs. These results indicated that salidroside may have potential applications as a therapeutic agent against vascular inflammation and atherosclerosis.

Comparative study of relationship between structure of phenylethanoid glycopyranosides and their activities using cell-free assays and human cells cultured in vitro

The study focused on protective potential of phytochemicals applicable in prevention and health protection is of great importance. Various structures of these compounds and a wide range of their biological activities have inspired organic chemists to sythesize their effective analogues in order to further increase their efficacy. The aims of our study were (i) to synthesize phenylethanoid glycopyranosides: salidroside (SALI - tyrosol β-d-glucopyranoside), tyrosol β-d-galactopyranoside (TYBGAL), tyrosol α-d-galactopyranoside (TYAGAL), tyrosol α-d-mannopyranoside (TYAMAN), hydroxytyrosol α-d-mannopyranoside (HOTAMA), homosyringyl β-d-glucopyranoside (HSYGLU), hydroxytyrosol β-d-xylopyranoside (HOTXYL) and hydroxysalidroside (HOSALI); (ii) to determine their antioxidant capacities (cell-free approaches); (iii) to evaluate their cytotoxicity (MTT test), protectivity against hydrogen peroxide (H₂O₂; comet assay) and effect on the intracellular glutathione level (iGSH; flow cytometry) in experimental system utilizing human hepatoma HepG2 cells. HOSALI, HOTAMA, HOTXYL and HSYGLU manifested the highest antioxidant capacity in cell-free assays and they were most active in protection of HepG2 cells against H₂O₂. On the other hand, pre-treatment of HepG2 cells with SALI had protective effects even though SALI displayed almost no activity in cell-free assays. Differences in the efficacy of the analogues revealed that structures of their molecules in terms of aglycone combined with sugar moiety affect their activities.

Salidroside Inhibits Lipopolysaccharide-ethanol-induced Activation of Proinflammatory Macrophages via Notch Signaling Pathway

Activation of macrophages is a key event for the pathogenesis of various inflammatory diseases. Notch signaling pathway recently has been found to be a critical pathway in the activation of proinflammatory macrophages. Salidroside (Sal), one of main bioactive components in Rhodiola crenulata (Hook. F. et Thoms) H. ohba, reportedly possesses anti-inflammatory activity and ameliorates inflammation in alcohol-induced hepatic injury. However, whether Sal regulates the activation of proinflammatory macrophages through Notch signaling pathway remains unknown. The present study investigated the effects of Sal on macrophage activation and its possible mechanisms by using both alcohol and lipopolysaccharide (LPS) to mimic the microenvironment of alcoholic liver. Detection of THP-1-derived macrophages exhibited that Sal could significantly decrease the expression of tumor necrosis factor-α (TNF-α), interleukin-1 beta (IL-1β) and IL-6 in the macrophages at both mRNA and protein levels. Furthermore, Sal significantly suppressed NF-κB activation via Notch-Hes signaling pathway in a dose-dependent manner. Moreover, in the microenvironment of alcoholic liver, the expression of Notch-dependent pyruvate dehydrogenase phosphatase 1 (PDP1) was elevated, and that of M1 gene expression [inducible NO synthase (NOS2)] was up-regulated. These changes could all be effectively ameliorated by Sal. The aforementioned findings demonstrated that Sal could inhibit LPS-ethanol-induced activation of proinflammatory macrophages via Notch signaling pathway.

GRP78/BIP/HSPA5 as a Therapeutic Target in Models of Parkinson's Disease: A Mini Review

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by selective loss of dopamine neurons in the substantia nigra pars compacta of the midbrain. Reports from postmortem studies in the human PD brain, and experimental PD models reveal that endoplasmic reticulum (ER) stress is implicated in the pathogenesis of PD. In times of stress, the unfolded or misfolded proteins overload the folding capacity of the ER to induce a condition generally known as ER stress. During ER stress, cells activate the unfolded protein response (UPR) to handle increasing amounts of abnormal proteins, and recent evidence has demonstrated the activation of the ER chaperone GRP78/BiP (78 kDa glucose-regulated protein/binding immunoglobulin protein), which is important for proper folding of newly synthesized and partly folded proteins to maintain protein homeostasis. Although the activation of this protein is essential for the initiation of the UPR in PD, there are inconsistent reports on its expression in various PD models. Consequently, this review article aims to summarize current knowledge on neuroprotective agents targeting the expression of GRP78/BiP in the regulation of ER stress in experimental PD models.

Effects of Modulation of Ion Channel Currents by Salidroside in H9C2 Myocardial Cells in Hypoxia and Reoxygenation

Salidroside, a phenyl-propanoid glycoside isolated from the medicinal plant Rhodiola rosea, has potent cardioprotective effects, especially against myocardial hypoxia and reoxygenation injury. However, the molecular mechanism underlying its action is still unclear. The aim of this study was to determine the effect of salidroside on sodium channel current (I_Na) and transient outward potassium channel current (I_to) in H9C2 cardiomyocytes. H9C2 cells were subcultured under anoxic conditions to mimic myocardial hypoxia and subsequently treated with salidroside. Whole cell patch clamp was performed to determine the effect of hypoxia/reoxygenation and salidroside on myocardial electrophysiological properties. In the differentiated H9C2 cells, hypoxia/reoxygenation reduced I_Na and I_to amplitude, while salidroside significantly restored both and altered the I_Na and I_to activation/inactivation kinetics in a dose-dependent manner. Our findings demonstrate that salidroside protects myocardial cells against hypoxia-reoxygenation by restoring the function of sodium and potassium channels.

Salidroside protects ATDC5 cells against lipopolysaccharide-induced injury through up-regulation of microRNA-145 in osteoarthritis

BACKGROUND

Osteoarthritis (OA) is a kind of degenerative disease characterized by the degeneration of the articular cartilage. Salidroside (SAL) is an active component of Rhodiola rosea L., which exhibits diverse pharmacological effects in different diseases. However, the effects of SAL on OA remain largely unclear. The study aimed to investigate the roles of SAL in lipopolysaccharides (LPS)-induced inflammatory injury in murine ATDC5 chondrocyte cells.

METHODS

LPS induced ATDC5 cell injury model was constructed by determining cell viability, apoptosis, apoptosis-associated factors as well as inflammatory cytokines expressions and concentrations. Then, the various concentrations of SAL were used to treat ATDC5 cells, and the effect of SAL on LPS-induce inflammatory injury was detected. After treatment with SAL, the expression level of miR-145 was measured by qRT-PCR. Subsequently, miR-145 inhibitor and corresponding control were transfected into ATDC5 cells to explore the influences of miR-145 in LPS-induce inflammatory injury. Besides, the key signaling pathways of NF-κB and p38MAPK were analyzed by using western blot.

RESULTS

LPS inhibited cell viability, induced apoptosis, activated cleaved-caspase-3/-9 expression, as well as increased IL-6, MCP-1 and TNF-α expressions and secretions in ATDC5 cells. SAL significantly alleviated LPS-induced inflammatory injury. Meanwhile, the expression of miR-145 was up-regulated by SAL. The protective effect of SAL on LPS-induced injury was obviously reversed by miR-145 inhibition. Furthermore, SAL inactivated NF-κB and p38MAPK signaling pathways by regulating miR-145.

CONCLUSIONS

These findings suggested that SAL could protect ATDC5 cells against LPS-induced injury via up-regulation of miR-145 in ATDC5 chondrocyte cells.

Salidroside protects LPS-induced injury in human thyroid follicular epithelial cells by upregulation of MiR-27a

AIMS

Hypothyroidism is a common endocrine disease without standard treatment. Salidroside (SAL) has various positive biological activities. In this study, experiments were performed to investigate whether SAL had protective effects on LPS-induced cell inflammatory injury.

MAIN METHODS

The human thyroid follicular epithelial cells (Nthy-ori 3-1) stimulated by LPS were treated with SAL and/or transfected with miR-27a inhibitor. Cell viability and cell apoptosis were detect by Cell Counting Kit-8 assay and flow cytometry, respectively. The expression of Cyclin D1 and apoptosis-related proteins, Notch proteins and NF-κB pathways related proteins were all measured by western blot. The expression of miR-27a and inflammatory chemokines MCP-1, IL-6 and TNF-α was examined by qRT-PCR. The protein weight of MCP-1, IL-6 and TNF-α was detected by ELISA.

KEY FINDINGS

LPS treatment induced cell injury by decreasing cell viability, and inducing cell apoptosis and inflammatory chemokines MCP-1, IL-6 and TNF-α. In addition, SAL alleviated LPS-induced cell injury by increasing cell viability, and decreasing cell apoptosis and inflammatory chemokines MCP-1, IL-6 and TNF-α. SAL upregulated miR-27a expression and further study showed that miR-27a downregulation impaired the protective effects of SAL. SAL downregulated the expression of Notch1/2, and phosphorylation of p65 and IκBα.

SIGNIFICANCE

SAL protects against LPS-induced injury in human thyroid follicular epithelial cells by upregulation of miR-27a. This process might be via inactivating Notch and NF-κB pathways.

Salidroside mitigates hypoxia/reoxygenation injury by alleviating endoplasmic reticulum stress‑induced apoptosis in H9c2 cardiomyocytes

Endoplasmic reticulum (ER) stress-induced apoptosis serves a crucial role in the development of myocardial ischemia/reperfusion (I/R) injury. Salidroside is a phenylpropanoid glycoside isolated from Rhodiola rosea L., which is a plant often used in traditional Chinese medicine. It possesses multiple pharmacological actions and protects against myocardial I/R injury in vitro and in vivo. However, it is not yet clear whether ER stress or ER stress-induced apoptosis contributes to the cardioprotective effects of salidroside against myocardial I/R injury. Hence, hypoxia/reoxygenation (H/R)-treated H9c2 cardiomyocytes were used in the current study to mimic myocardium I/R injury in vivo. It was hypothesized that salidroside alleviates ER stress and ER stress-induced apoptosis, thereby reducing H/R injury in H9c2 cells. The results demonstrated that salidroside attenuated H/R-induced H9c2 cardiomyocyte injury, as cell viability was increased, lactate dehydrogenase release was decreased, morphological changes in apoptotic cells were ameliorated and the apoptosis ratio was reduced compared with the H/R group. ER stress was reversed, indicated by the downregulation of glucose regulated protein 78 and C/EBP homologous protein following pretreatment with salidroside. In addition, salidroside attenuated ER stress-induced apoptosis, as the expression of cleaved caspase-12 and pro-apoptotic protein Bcl-2 associated X protein and activity of caspase-3 was decreased, while the expression of anti-apoptotic protein Bcl-2 was increased following pretreatment with salidroside. Furthermore, the results indicated that salidroside decreases the activation of the ER stress-associated signaling pathway, as the expression of phosphorylated protein kinase RNA (PKR)-like ER kinase (p-PERK) and phosphorylated inositol-requiring enzyme-1α (p-IRE1α) proteins were decreased following pretreatment with salidroside. These results demonstrate that salidroside protects against H/R injury via regulation of the PERK and IRE1α pathways, resulting in alleviation of ER stress or ER stress-induced apoptosis in H9c2 cardiomyocytes.

Bioaccessibility and Absorption Mechanism of Phenylethanoid Glycosides Using Simulated Digestion/Caco-2 Intestinal Cell Models

Acteoside and salidroside are major phenylethanoid glycosides (PhGs) in Osmanthus fragrans Lour. flowers with extensive pharmacological activities and poor oral bioavailability. The absorption mechanisms of these two compounds remain unclear. This study aimed to investigate the bioaccessibility of these compounds using an in vitro gastrointestinal digestion model and to examine the absorption and transport mechanisms of PhGs using the Caco-2 cell model. The in vitro digestion model revealed that the bioaccessibility of salidroside (98.7 ± 1.35%) was higher than that of acteoside (50.1 ± 3.04%), and the superior bioaccessibility of salidroside can be attributed to its stability. The absorption percentages of total phenylethanoid glycoside, salidroside, and acteoside were 1.42-1.54%, 2.10-2.68%, and 0.461-0.698% in the Caco-2 model, respectively. Salidroside permeated Caco-2 cell monolayers through passive diffusion. At the concentration of 200 μg/mL, the apparent permeability ( P_app) of salidroside in the basolateral (BL)-to-apical (AP) direction was 23.7 ± 1.33 × 10^-7 cm/s, which was 1.09-fold of that in the AP-to-BL direction (21.7 ± 1.38 × 10^-7 cm/s). Acteoside was poorly absorbed with low P_app (AP to BL) (4.75 ± 0.251 × 10^-7 cm/s), and its permeation mechanism was passive diffusion with active efflux mediated by P-glycoprotein (P-gp). This study clarified the bioaccessibility, absorption, and transport mechanisms of PhGs. It also demonstrated that the low bioavailability of acteoside might be attributed to its poor bioaccessibility, low absorption, and P-gp efflux transporter.

Salidroside inhibits the proliferation and migration of gastric cancer cells via suppression of Src‑associated signaling pathway activation and heat shock protein 70 expression

Salidroside, an active ingredient extracted from the Rhodiola rosea plant, has potential anti-tumor effects. However, the effects of salidroside on gastric cancer cell proliferation and migration remain unclear. In the present study, the inhibitory effects of salidroside on gastric cancer cell proliferation, migration and invasion and the molecular mechanisms underlying these effects were investigated. The human gastric cancer cell line, BGC-823, was treated with different concentrations of salidroside (200, 400 and 600 µg/ml). Cell proliferation was determined with Cell Counting Kit-8 and colony formation assays, and the migration and invasion of cells was detected by a wound healing and Transwell assay, respectively. Western blotting was performed to detect the levels of N-cadherin, E-cadherin and heat shock protein (HSP)70. In addition, the phosphorylation of proto-oncogene tyrosine-protein kinase Src (Src), protein kinase B (Akt), mitogen activated protein kinase 1 (ERK), signal transducer and activator of transcription (STAT)3 and focal adhesion kinase 1 (FAK) was examined by western blotting. The levels of matrix metalloproteinase (MMP)-2 and MMP-9 were determined by enzyme-linked immunosorbent assay kits. Levels of reactive oxygen species (ROS) in cells were measured by a fluorescence plate reader with dichloro-dihydro-fluorescein diacetate. The results indicated that salidroside significantly suppressed cell proliferation and colony formation, inhibited cell migration and invasion, increased E-cadherin expression and decreased N-cadherin, MMP-2 and MMP-9 expression. Furthermore, salidroside suppressed ROS production and subsequently reduced the phosphorylation of Src, Akt, ERK and FAK. Salidroside also inhibited HSP70 expression, and HSP70 overexpression reversed the inhibitory effects of salidroside on BGC-823 cell proliferation, migration and invasion. In conclusion, the present study revealed that salidroside inhibited the proliferation, migration and invasion of BGC-823 cells by downregulating ROS-mediated Src-associated signaling pathway activation and HSP70 expression.

Salidroside Inhibits Inflammation Through PI3K/Akt/HIF Signaling After Focal Cerebral Ischemia in Rats

Salidroside is being investigated for its therapeutic potential in stroke because it is neuroprotective over an extended therapeutic window of time. In the present study, we investigated the mechanisms underlying the anti-inflammatory effects of salidroside (50 mg/kg intraperitoneally) in rats, given 1 h after reperfusion of a middle cerebral artery that had been occluded for 2 h. After 24 h, we found that salidroside increased the neuronal nuclear protein NeuN and reduced the marker of microglia and macrophages CD11b in the peri-infarct area of the brain. Salidroside also decreased IL-6, IL-1β, TNF-α, CD14, CD44, and iNOs mRNAs. At the same time, salidroside increased the ratio of phosphorylated protein kinase B (p-Akt) to total Akt. The phosphoinositide 3-kinase (PI3K) inhibitor LY294002 prevented this increase in p-Akt and reversed the inhibitory effects of salidroside on CD11b and inflammatory mediators. Salidroside also elevated the protein levels of hypoxia-inducible factor (HIF) subunits HIF1α, HIF2α, HIF3α, and of erythropoietin (EPO). The stimulatory effects of salidroside on HIFα subunits were blocked by LY294002. Moreover, YC-1, a HIF inhibitor, abolished salidroside-mediated increase of HIF1α and prevented the inhibitory effects of salidroside on CD11b and inflammatory mediators. Taken together, our results provide evidence for the first time that all three HIFα subunits and EPO can be regulated by PI3K/Akt in cerebral tissue, and that salidroside entrains this signaling pathway to induce production of HIFα subunits and EPO, one or more of which mediate the anti-inflammatory effects of salidroside after cerebral IRI.

Hongjingtian Injection Attenuates Myocardial Oxidative Damage via Promoting Autophagy and Inhibiting Apoptosis

Natural products with antioxidative activities are widely applied to prevent and treat various oxidative stress related diseases, including ischemic heart disease. However, the cellular and molecular mechanisms of those therapies are still needed to be illustrated. In this study, we characterized the cardioprotective effects of Hongjingtian Injection (HJT), an extensively used botanical drug for treating coronary heart disease. The H/R-induced profound elevation of oxidative stress was suppressed by HJT. HJT also attenuates oxidative injury by promoting cell viability, intracellular ATP contents, and mitochondrial oxygen consumption. Validation experiments indicated that HJT inhibited H/R-induced apoptosis and regulated the expression of apoptosis-associated proteins Bcl-2 and cleaved caspase3. Interestingly, HJT significantly regulated the expression of autophagy-related proteins LC3, Beclin, and mTOR as well as ERK and AKT. We provide evidence that the mechanism involves activation of AKT/Beclin-1, AKT, and ERK/mTOR pathway in cardiomyocyte autophagy. Histological and physiological evaluation revealed that HJT significantly decreased the infarct area of the heart, improved cardiac function, and increased the expression of LC3B in a rat model of coronary occlusion. From the obtained data, we proposed that HJT diminished myocardial oxidative damage through regulating the balance of autophagy and apoptosis and reducing oxidative stress.

Altered expression of TRAIL on mouse T cells via ERK phosphorylation by Rhodiola rosea L. and its marker compounds

Rhodiola rosea L. extracts have shown neuroprotective, anti-fatigue, anti-inflammatory and anti-tumor properties. However, the studies on their effect on T cell function are rather scarce. We examined the potential of R. rosea extract and its major constituents - salidroside, rosarin, rosavin and rosin to alter cell growth of human Jurkat T cells, apoptosis of splenic mouse CD3 T cells and expression of the surface markers and phosphorylation of extracellular signal-regulated kinase (ERK). The initial screening for cell viability in Jurkat T cells and for apoptosis of mouse T cells showed the strongest activity for rosavin and rosarin. Rosarin and rosavin did not alter significantly the dynamic of CD69 expression upon stimulation, but altered TNF-related apoptosis-inducing ligand (TRAIL) expression. Rosavin inhibited TRAIL up-regulation, while rosarin showed an opposite effect. Indeed, rosarin increased the frequencies of CD3⁺TRAIL⁺ T cells and the fold inhibition of ERK phosphorylation. Our data showed that different effects of rosarin and rosavin on TRAIL expression can involve distinct action on ERK signaling and hence highlighted their potential to manipulate TRAIL as a tool to rescue the resistance to apoptosis in autoimmune diseases and cancer.

Induction of autophagy by salidroside through the AMPK-mTOR pathway protects vascular endothelial cells from oxidative stress-induced apoptosis

Vascular endothelial cells are highly sensitive to oxidative stress, and this is one of the mechanisms by which widespread endothelial dysfunction is induced in most cardiovascular diseases and disorders. However, how these cells can survive in oxidative stress environments remains unclear. Salidroside, a traditional Chinese medicine, has been shown to confer vascular protective effects. We aimed to understand the role of autophagy and its regulatory mechanisms by treating human umbilical vein endothelial cells (HUVECs) with salidroside under oxidative stress. HUVECs were treated with salidroside and exposed to hydrogen peroxide (H₂O₂). The results indicated that salidroside exerted cytoprotective effects in an H₂O₂-induced HUVEC injury model and suppressed H₂O₂-induced apoptosis of HUVECs. Pretreatment with 3-methyladenine (3-MA), an autophagy inhibitor, increased oxidative stress-induced HUVEC apoptosis, while the autophagy activator rapamycin induced anti-apoptosis effects in HUVECs. Salidroside increased autophagy and decreased apoptosis of HUVECs in a dose-dependent manner under oxidative stress. Moreover, 3-MA attenuated salidroside-induced HUVEC autophagy and promoted apoptosis, whereas rapamycin had no additional effects compared with salidroside alone. Salidroside upregulated AMPK phosphorylation but downregulated mTOR phosphorylation under oxidative stress; however, administration of compound C, an AMPK inhibitor, abrogated AMPK phosphorylation and increased mTOR phosphorylation and apoptosis compared with salidroside alone. These results suggest that autophagy is a protective mechanism in HUVECs under oxidative stress and that salidroside might promote autophagy through activation of the AMPK pathway and downregulation of mTOR pathway.

Salidroside Regulates Inflammatory Response in Raw 264.7 Macrophages via TLR4/TAK1 and Ameliorates Inflammation in Alcohol Binge Drinking-Induced Liver Injury

The current study was designed to investigate the anti-inflammatory effect of salidroside (SDS) and the underlying mechanism by using lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages in vitro and a mouse model of binge drinking-induced liver injury in vivo. SDS downregulated protein expression of toll-like receptor 4 (TLR4) and CD14. SDS inhibited LPS-triggered phosphorylation of LPS-activated kinase 1 (TAK1), p38, c-Jun terminal kinase (JNK), and extracellular signal-regulated kinase (ERK). Degradation of IκB-α and nuclear translocation of nuclear factor (NF)-κB were effectively blocked by SDS. SDS concentration-dependently suppressed LPS mediated inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein levels, as well as their downstream products, NO. SDS significantly inhibited protein secretion and mRNA expression of of interleukin (IL)-1β and tumor necrosis factor (TNF)-α. Additionally C57BL/6 mice were orally administrated SDS for continuous 5 days, followed by three gavages of ethanol every 30 min. Alcohol binge drinking caused the increasing of hepatic lipid accumulation and serum transaminases levels. SDS pretreatment significantly alleviated liver inflammatory changes and serum transaminases levels. Further investigation indicated that SDS markedly decreased protein level of IL-1β in serum. Taken together, these data implied that SDS inhibits liver inflammation both in vitro and in vivo, and may be a promising candidate for the treatment of inflammatory liver injury.

Salidroside exhibits anti-dengue virus activity by upregulating host innate immune factors

Dengue is an arboviral disease with no effective therapy available. Therefore, there is an urgent need to find a potent antiviral agent against dengue virus (DENV). In the present study, salidroside, a main bioactive compound of Rhodiola rosea, was evaluated for its antiviral potential against DENV serotype-2 infection and its effect on host innate immune factors. Antiviral effects of salidroside were examined in DENV-infected cells by western blotting, flow cytometry and real-time PCR. Its underlying mechanism involved in antiviral action was determined by evaluating expression of host innate immune factors including RIG-I, IRF-3, IRF-7, PKR, P-eIF2α and NF-κB. Salidroside potently inhibited DENV infection by decreasing DENV envelope protein expression more than tenfold. Salidroside exerts its antiviral activity by increasing expression of RNA helicases such as RIG-I, thereby initiating a downstream signaling cascade that induces upregulation of IRF-3 and IRF-7. It prevents viral protein synthesis by increasing the expression of PKR and P-eIF2α while decreasing NF-κB expression. It was also found to induce the expression of IFN-α. In addition, the number of NK cells and CD8⁺ T cells were also found to be increased by salidroside treatment in human PBMCs, which are important in limiting DENV replication during early stages of infection. The findings presented here suggest that salidroside exhibits antiviral activity against DENV by inhibiting viral protein synthesis and boosting host immunity by increasing the expression of host innate immune factors and hence could be considered for the development of an effective therapeutic agent against DENV infection.

Cucurbita moschata Duch. and its active component, β-carotene effectively promote the immune responses through the activation of splenocytes and macrophages

Cucurbita moschata Duch. has long been used for traditional health food in many countries. However, to enhance the immune system of Cucurbita moschata Duch. and its major component, β-carotene is not clear. Here, we determined the immune enhancement effect of Cucurbita moschata Duch. and β-carotene in mouse splenocytes and RAW 264.7 macrophage cell line. We prepared baked Cucurbita moschata Duch. (Sweetme Sweet Pumpkin(TM), SSP) and steamed Cucurbita moschata Duch. (SC). Splenocytes isolated from the spleen of BALB/c mice were treated with SSP, SC, and β-carotene for 24 h. RAW 264.7 cells were stimulated with recombinant interferon-γ (rIFN-γ) for 6 h before treatment with SSP, SC, or β-carotene. SSP, SC and β-carotene significantly up-regulated the proliferation of splenocyte and mRNA expression of KI-67. The levels of interleukin-2 and IFN-γ were up-regulated by SSP, SC, or β-carotene in the splenocytes. SC and β-carotene also increased the levels of tumor necrosis factor-α (TNF-α) in the splenocytes. In addition, SSP, SC, or β-carotene significantly increased the levels of TNF-α through the nuclear translocation of the nuclear factor-κB and phosphorylation of IκBα in the rIFN-γ-primed RAW 264.7 cells. These data indicate that Cucurbita moschata Duch. and β-carotene may have an immune-enhancing effect through the production of Th1 cytokines by activation of splenocytes and macrophages.

Salidroside Protects Against 6-Hydroxydopamine-Induced Cytotoxicity by Attenuating ER Stress

Parkinson's disease (PD) is a neurodegenerative disease characterized by a persistent decline of dopaminergic (DA) neurons in the substantia nigra pars compacta. Despite its frequency, effective therapeutic strategies that halt the neurodegenerative processes are lacking, reinforcing the need to better understand the molecular drivers of this disease. Importantly, increasing evidence suggests that the endoplasmic reticulum (ER) stress-induced unfolded protein response is likely involved in DA neuronal death. Salidroside, a major compound isolated from Rhodiola rosea L., possesses potent anti-oxidative stress properties and protects against DA neuronal death. However, the underlying mechanisms are not well understood. In the present study, we demonstrate that salidroside prevents 6-hydroxydopamine (6-OHDA)-induced cytotoxicity by attenuating ER stress. Furthermore, treatment of a DA neuronal cell line (SN4741) and primary cortical neurons with salidroside significantly reduced neurotoxin-induced increases in cytoplasmic reactive oxygen species and calcium, both of which cause ER stress, and cleaved caspase-12, which is responsible for ER stress-induced cell death. Together, these results suggest that salidroside protects SN4741 cells and primary cortical neurons from 6-OHDA-induced neurotoxicity by attenuating ER stress. This provides a rationale for the investigation of salidroside as a potential therapeutic agent in animal models of PD.

A novel fibrinogenase from Agkistrodon acutus venom protects against LPS-induced endotoxemia via regulating NF-κB pathway

CONTEXT

Endotoxins including lipopolysaccharide (LPS) could cause endotoxemia which often results in excessive inflammation, organ dysfunction, sepsis, disseminated intravascular coagulation (DIC) or even death. Previously, a novel fibrinogenase (FII) showed protective effects on LPS-induced DIC via activating protein C and suppressing inflammatory cytokines.

OBJECTIVE

To evaluate whether FII has protective effect on LPS-induced endotoxemia in mice and learn about the role of NF-κB pathway in TNF-α producing process.

METHODS

BALB/C mice were intraperitoneally injected (i.p.) with (a) 30 mg/kg LPS, (b) LPS + 0.3 mg/kg FII, (c) LPS + 1.0 mg/kg FII, (d) LPS + 3.0 mg/kg FII or (e) saline. Both survival rate and organ function were tested, including alanine aminotransferase (ALT), blood urine nitrogen (BUN) and tissue section, and TNF-α was examined by ELISA. RAW 264.7 macrophage was administered with (a) LPS, (b) LPS + FII, (c) FII alone or (d) saline, and TNF-α and phosphorylation (P)-NF-κB (P65) were determined by Western blot.

RESULTS

The administration of LPS led to 65% mortality rate, a rise of serum TNF-α, BUN and ALT levels, and both liver and renal tissue damage were observed. While FII treatment significantly increased the survival rate of LPS-induced endotoxemia mice model, histopathology and protein analysis results also revealed that FII remarkably protected liver and renal from LPS damage as well as decreasing TNF-α level. In vitro, FII significantly decreased LPS-induced TNF-α production and the expression of P-NF-κB (P65).

CONCLUSIONS

Our findings suggested that FII had protective effect on LPS-induced endotoxemia and organ injuries by suppressing the activation of NF-κB which decreased TNF-α level.

Rhodiola plants: Chemistry and biological activity

Rhodiola is a genus of medicinal plants that originated in Asia and Europe and are used traditionally as adaptogens, antidepressants, and anti-inflammatory remedies. Rhodiola plants are rich in polyphenols, and salidroside and tyrosol are the primary bioactive marker compounds in the standardized extracts of Rhodiola rosea. This review article summarizes the bioactivities, including adaptogenic, antifatigue, antidepressant, antioxidant, anti-inflammatory, antinoception, and anticancer activities, and the modulation of immune function of Rhodiola plants and its two constituents, as well as their potential to prevent cardiovascular, neuronal, liver, and skin disorders.

Anti-asthma effects of synthetic salidroside through regulation of Th1/Th2 balance

AIM

The aim of the study was to investigate the effect and mechanism of action of synthetic salidroside in an ovalbumin (OVA)-induced asthma model in mice.

METHOD

BALB/c mice were sensitized with an intraperitoneal injection of ovalbumin (OVA) to induce a mouse model of asthma in paracmasis. The mice were treated with dexamethasone as the positive control. At the end of the study, respiratory reactivity was detected, the numbers of various kinds of white blood cells in the bronchoalveolar lavage fluid (BALF) were counted, and the levels of IL-4 and INF-γ in BALF were determined. Quantitative PCR was used to detect the mRNA contents of IL-4 and INF-γ in lung tissue. Histologic examination was performed to observe inflammatory cellular infiltration.

RESULTS

Salidroside treatment virtually eliminated airway hyper-reactivity, markedly reduced the eosinophil percent, obviously reduced the levels of IL-4 and raised INF-γ in the bronchoalveolar lavage fluid (BALF) compared with the sham-treated group. Quantitative PCR on the mRNA content of IL-4 and INF-γ provided confirmation. Lung histologic observations showed that salidroside reduced inflammation and edema. These effects were equivalent to the effects of dexamethasone.

CONCLUSION

Synthetic salidroside exhibits an anti-asthma effect which is related to the regulation of Th1/Th2 balance. This provides a new possibility for treatment of allergic asthma.

Salidroside protects against premature senescence induced by ultraviolet B irradiation in human dermal fibroblasts

OBJECTIVES

Salidroside, the predominant component of a Chinese herbal medicine, Rhodiola rosea L., becomes an attractive bio-agent due to its multifunction. Although it is well proposed that this herbal medicine may have photoprotective effect according to the folk hearsay, the direct supportive experimental evidences linking the drug with skin ageing have rarely been reported so far. The study was conducted to investigate the photoprotective role of salidrosdie and its related mechanisms in vitro.

METHODS

First, a premature senescence model induced by UVB irradiation (250 mJ cm(-2)) in human dermal fibroblasts (HDFs) was established, and senescent phenotypes were evaluated by cell morphology, cell proliferation, senescence-associated beta-galactosidase (SA-β-gal) activity and cell cycle distribution. Then the photoprotective effect of salidroside was investigated. Cells were pre-treated with various doses of salidroside (1, 5 and 10 μM) followed by the sublethal dosage of UVB exposure and then were harvested for various detections, including senescence-associated phenotypes and molecules, alteration of oxidative stress, matrix metalloproteinase-1 (MMP-1) secretion and inflammatory response.

RESULTS

Pre-treatment of salidroside dose dependently reversed the senescent state of HDFs induced by UVB as evidenced by elevated cell viability, decreased SA-β-gal activity and relieving of G1/G0 cell cycle arrest. UVB-induced increased protein expression of cyclin-dependent kinase (CDK) inhibitors p21(WAF) (1) and p16(INK) (4) was also repressed by salidrosdie treatment in a dose-dependent manner. Meanwhile, the increment of malondialdehyde (MDA) level in UVB-irradiated HDFs was inhibited upon salidroside treatment. Additionally, salidroside significantly attenuated UVB-induced synthesis of MMP-1 as well as the production of IL-6 and TNF-α in HDFs.

CONCLUSION

Our data provided the evidences for the protective role of salidroside against UVB-induced premature senescence in HDFs probably via its anti-oxidative property and inhibition on production of MMP-1 and pro-inflammatory cytokines, which indicated its potential utilization as an active ingredient in the preparation of photoprotective formulation.

Salidroside protects Caenorhabditis elegans neurons from polyglutamine-mediated toxicity by reducing oxidative stress

Polyglutamine (polyQ) aggregation plays a pivotal role in the pathological process of Huntington's disease and other polyQ disorders. Therefore, strategies aiming at restoring dysfunction and reducing stresses mediated by polyQ toxicity are of therapeutic interest for proteotoxicity diseases. Salidroside, a glycoside from Rhodiola rosea, has been shown to have a variety of bioactivities, including antioxidant activity. Using transgenic Caenorhabditis elegans models, we show here that salidroside is able to reduce neuronal death and behavioral dysfunction mediated by polyQ expressed in ASH neurons, but the neuroprotective effect is not associated with prevention of polyQ aggregation per se. Further experiments reveal that the neuroprotective effect of salidroside in C. elegans models involves its antioxidant capabilities, including decrease of ROS levels and paraquat-induced mortality, increase of antioxidant enzyme activities and reduction of lipid peroxidation. These results demonstrate that salidroside exerts its neuroprotective function against polyQ toxicity via oxidative stress pathways.