Adjuvant effects of salidroside fromRhodiola roseaL. on the immune responses to ovalbumin in mice

Pharmacological functions of salidroside in renal diseases: facts and perspectives

Rhodiola rosea is a valuable functional medicinal plant widely utilized in China and other Asian countries for its anti-fatigue, anti-aging, and altitude sickness prevention properties. Salidroside, a most active constituent derived from Rhodiola rosea, exhibits potent antioxidative, hypoxia-resistant, anti-inflammatory, anticancer, and anti-aging effects that have garnered significant attention. The appreciation of the pharmacological role of salidroside has burgeoned over the last decade, making it a beneficial option for the prevention and treatment of multiple diseases, including atherosclerosis, Alzheimer's disease, Parkinson's disease, cardiovascular disease, and more. With its anti-aging and renoprotective effects, in parallel with the inhibition of oxidative stress and inflammation, salidroside holds promise as a potential therapeutic agent for kidney damage. This article provides an overview of the microinflammatory state in kidney disease and discuss the current therapeutic strategies, with a particular focus on highlighting the recent advancements in utilizing salidroside for renal disease. The potential mechanisms of action of salidroside are primarily associated with the regulation of gene and protein expression in glomerular endothelial cells, podocytes, renal tubule cells, renal mesangial cells and renal cell carcinoma cell, including TNF-α, TGF-β, IL-1β, IL-17A, IL-6, MCP-1, Bcl-2, VEGF, ECM protein, caspase-3, HIF-1α, BIM, as well as the modulation of AMPK/SIRT1, Nrf2/HO-1, Sirt1/PGC-1α, ROS/Src/Cav-1, Akt/GSK-3β, TXNIP-NLRP3, ERK1/2, TGF-β1/Smad2/3, PI3K/Akt, Wnt1/Wnt3a β-catenin, TLR4/NF-κB, MAPK, JAK2/STAT3, SIRT1/Nrf2 pathways. To the best of our knowledge, this review is the first to comprehensively cover the protective effects of salidroside on diverse renal diseases, and suggests that salidroside has great potential to be developed as a drug for the prevention and treatment of metabolic syndrome, cardiovascular and cerebrovascular diseases and renal complications.

Indian Medicinal Plants and Formulations and Their Potential Against COVID-19-Preclinical and Clinical Research

The cases of COVID-19 are still increasing day-by-day worldwide, even after a year of its first occurrence in Wuhan city of China. The spreading of SARS-CoV-2 infection is very fast and different from other SARS-CoV infections possibly due to structural differences in S proteins. The patients with severe diseases may die due to acute respiratory distress syndrome (ARDS) caused by systemic inflammatory reactions due to the excessive release of pro-inflammatory cytokines and chemokines by the immune effector cells. In India too, it is spreading very rapidly, although the case fatality rate is below 1.50% (https://www.statista.com), which is markedly less than in other countries, despite the dense population and minimal health infrastructure in rural areas. This may be due to the routine use of many immunomodulator medicinal plants and traditional AYUSH formulations by the Indian people. This communication reviews the AYUSH recommended formulations and their ingredients, routinely used medicinal plants and formulations by Indian population as well as other promising Indian medicinal plants, which can be tested against COVID-19. Special emphasis is placed on Indian medicinal plants reported for antiviral, immunomodulatory and anti-allergic/anti-inflammatory activities and they are categorized for prioritization in research on the basis of earlier reports. The traditional AYUSH medicines currently under clinical trials against COVID-19 are also discussed as well as furtherance of pre-clinical and clinical testing of the potential traditional medicines against COVID-19 and SARS-CoV-2. The results of the clinical studies on AYUSH drugs will guide the policymakers from the AYUSH systems of medicines to maneuver their policies for public health, provide information to the global scientific community and could form a platform for collaborative studies at national and global levels. It is thereby suggested that promising AYUSH formulations and Indian medicinal plants must be investigated on a priority basis to solve the current crisis.

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.

Contribution of salidroside to the relieve of symptom and sign in the early acute stage of osteoarthritis in rat model

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Rhodiola has been used to treat cough, hemoptysis, fever, pain, bruise and other symptoms which are related to injury and inflammation over a thousand years in traditional Tibetan medicine. Salidroside (p-hydroxyphenethyl-β-D-glucoside) is one of the most potent bioactive ingredients of the genus Rhodiola.

AIM OF STUDY

The present study aimed to explore whether salidroside could alleviate the clinical symptom and sign in the early acute stage of osteoarthritis (OA) in monosodium iodoacetate (MIA) rat model, and its underlying mechanisms.

MATERIALS AND METHODS

Osteoarthritis (OA) was induced in rat knees by intra-articular injection of MIA; simultaneously salidroside was administered by intravenous injection. Pain behaviors were evaluated by knee-bend test, hind limb weight-bearing asymmetry and hind paw mechanical withdrawal threshold. The joint swelling was determined by the difference of knee joint diameter. Inflammatory exudates in synovial fluid were evaluated by leukocyte counting and protein content. Cytokines, chemokines, reactive oxygen species (ROS) and reactive nitrogen species (RNS) markers were determined by Enzyme-linked immunosorbent assay (ELISA) and colorimetric assay in synovial fluid. Pro-inflammatory gene expressions in synovial tissue were detected by quantitative real time RT-PCR (qRT-PCR). Nuclear factor kappa-B (NF-κB) DNA binding assay and western blot were used to determine NF-κB activation and ROS marker protein expression in synovial tissue. Glycosaminoglycan (GAG) content in the cartilage was measured by dimethylmethylene blue method. Hematoxylin and eosin (H&E), Safranin O-fast green and a modified Mankin grading system were used to evaluate the histology of articular cartilage.

RESULTS

Salidroside could alleviate pain and joint swelling in the early acute stage of OA in rat model, reduced the number of leukocytes, total protein content, proinflammatory mediators and ROS/RNS markers in synovial fluid, down regulated the expression of proinflammatory genes in synovium, inhibited the activation of NF- κ B and oxidative stress response in synovium, promoted the synthesis of cartilage GAG, prevented the loss of proteoglycan and chondrocyte degeneration.

CONCLUSIONS

Salidroside effectively alleviates acute symptom and sign of OA in rat model by its anti-inflammatory and antioxidant affects to inhibit synovial inflammation, which provides a new strategy to prevent the onset and progression of OA.

Salidroside as a potential neuroprotective agent for ischemic stroke: a review of sources, pharmacokinetics, mechanism and safety

Salidroside (Sal) is a bioactive extract principally from traditional herbal medicine such as Rhodiola rosea L., which has been commonly used for hundreds of years in Asia countries. The excellent neuroprotective capacity of Sal has been illuminated in recent studies. This work focused on the source, pharmacokinetics, safety and anti-ischemic stroke (IS) effect of Sal, especially emphasizing its mechanism of action and BBB permeability. Extensive databases, including Pubmed, Web of science (WOS), Google Scholar and China National Knowledge Infrastructure (CNKI), were applied to obtain relevant online literatures. Sal exerts powerful therapeutic effects on IS in experimental models either in vitro or in vivo due to its neuroprotection, with significantly diminishing infarct size, preventing cerebral edema and improving neurological function. Also, the findings suggest the underlying mechanisms involve anti-oxidation, anti-inflammation and anti-apoptosis by regulating multiple signaling pathways and key molecules, such as NF-κB, TNF-α and PI3K/Akt pathway. In pharmacokinetics, although showing a rapid absorption and elimination, bioavailability of Sal is elevated under some non-physiological conditions. The component and its metabolite (tyrosol) are capable of distributing to brain tissue and the later keeps a higher level of concentration. Moreover, Sal scarcely has obvious toxicity or side effects in a variety of animal experiments and clinical trials, but combination of drugs and perinatal use of medicine should be taken more attentions. Finally, as an active ingredient, not only is Sal isolated from diverse plants with limited yield, but also large batches of the products can be harvested by biological and chemical synthesis. With higher efficacy and better safety profiles, Sal could sever as a promising neuroprotectant for preventing and treating IS. Nevertheless, further investigations are still required to explore the pharmacodynamic and pharmacokinetic properties of Sal in the treatment of IS.

Advances in research on the effects of natural drugs with immune-promoting effects on immune function

Immune-enhanced natural medicines have gradually formed unique functions and usages through long-term medical practice, which contained rich immunological ideas and contents. The immune-enhancing natural medicine has a wide range of pharmacological effects in anti-inflammatory, anti-tumor, anti-viral, and immunity enhancement. In recent years, great progress has been made in the study of immune-enhanced natural drugs. In this article, the main active ingredients of some natural drugs with immune-enhancing function are reviewed, which can enhance immunity by regulating the level of some cytokines and affecting the function of non-specific immunity and specific immunity. The experimental research provides the basis and prospects for the research and development of immune-enhanced natural drugs in the future, providing new ideas for immunotherapy.

Salidroside suppresses group 2 innate lymphoid cell-mediated allergic airway inflammation by targeting IL-33/ST2 axis

Salidroside, an active component extracted from Rhodiola rosea, has been reported to inhibit allergic asthma. However, its mechanism has not been fully elucidated. Group 2 innate lymphoid cells (ILC2s) accumulate in the lung and cooperate with other cells to drive type 2 inflammation stimulated by inhaled allergens. The study aims to explore the suppressive effect of salidroside on ILC2s and IL-33/IL-33R (ST2) axis in allergic airway inflammation. The ovalbumin (OVA)-sensitized/challenged mice were established. Airway eosinophil recruitment, increased total IgE in the serum and type 2 cytokines IL-4, IL-5, and IL-13 in the bronchoalveolar lavage fluids and lung tissues were identified in the OVA-induced mice model, all of which were inhibited by pretreatment with different doses of salidroside. Moreover, salidroside suppressed lung total ILC2 and ST2-expressing ILC2 accumulation, lung IL-33 and ST2 expressions in mice. In vitro, OVA could induce IL-33 expression in BEAS-2B cells, which was also effectively inhibited by salidroside. This study firstly reveals salidroside as a potential therapeutic drug for allergic asthma by inhibiting ILC2-mediated airway inflammation via targeting IL-33/ST2 axis.

Salidroside enhances the anti-cancerous effect of imatinib on human acute monocytic leukemia via the induction of autophagy-related apoptosis through AMPK activation

As the typical tyrosine kinase inhibitor, imatinib has been the first-line antineoplastic agent for both chronic myeloid leukemia and acute lymphoblastic leukemia. However, a large number of patients are still resistant to the benefits of imatinib, and they have a dissatisfactory prognosis. Salidroside, a compound that is extracted from natural plants, has been reported to have an excellent anticancer effect and few side effects. In the present study, we have developed a new combination therapy strategy of salidroside and imatinib for combating the growth of acute lymphoblastic leukemia. As demonstrated by the anti-proliferation assay, salidroside exhibited excellent cytotoxicity against myeloid leukemia cells. Moreover, cells treated by the combination therapy of salidroside and imatinib displayed a clear lower growth rate than cells only treated by imatinib, indicating that salidroside has a positive effect on enhancing the cytotoxicity of imatinib against leukemia cells. Subsequently, the underlying mechanisms were investigated. The results revealed that autophagy marker proteins in leukemia cells, including LC3, p62, and Beclin1, displayed a significant expression change after treating them with salidroside plus imatinib, with the levels of LC3 and Beclin1 dramatically increasing while the expression of p62 was significantly decreased. Moreover, an obvious down-regulation of p-PI3K, p-AKT and p-mTOR expression levels in leukemia cells after treatment with salidroside plus imatinib suggested that the PI3K/mTOR pathway plays an important role in the process of cell apoptosis induced by salidroside or imatinib. Further studies showed that pre-incubating the cells with an autophagy inhibitor dramatically inhibited the ability of imatinib to induce autophagy, but did not inhibit the ability of salidroside. The underlying causes were subsequently explored and the results showed that silencing AMPKα1, the most important regulator of autophagy, dramatically attenuates the ability of salidroside to induce cell apoptosis. These results together indicated that salidroside enhances the cytotoxicity of imatinib on acute monocytic leukemia via the induction of autophagy-related apoptosis through AMPK activation. The unique advantages of combination therapy were further confirmed by in vivo experiments, with the tumor-bearing cells treated with salidroside plus imatinib achieving the best anti-tumor effect.

Salidroside improves brain ischemic injury by activating PI3K/Akt pathway and reduces complications induced by delayed tPA treatment

Cerebral ischemia causes blood-brain barrier (BBB) injury and thus increases the risk of complications secondary to thrombolysis, which limited its clinical application. This study aims to clarify the role and mechanism of salidroside (SALD) in alleviating brain ischemic injury and whether pretreatment of it could improve prognosis of delayed treatment of tissue plasminogen activator (t-PA). Rats were subjected to 3 h of middle cerebral artery occlusion (MCAO) and were intraperitoneally administered with 10, 20 or 40 mg/kg SALD before ischemia. 1.5% 5-triphenyl-2H-tetrazolium chloride (TTC) staining and neurological studies were performed to observe the effectiveness of SALD. The expressions and the distribution of phosphoinositide-3-kinase/protein kinase B (PI3K/Akt) signaling were analyzed. Experiments were further conducted in isolated microvessels and human brain microvascular endothelial cells (HBMECs) to explore the protective mechanism of SALD. Finally, rats were subjected to 6 h of MCAO and 24 h of reperfusion. tPA was given with or without the pretreatment of SALD. Various approaches including gelatin zymography, western blot and immunofluorescence were used to evaluate the effect of this combination therapy. SALD could reduce cerebral ischemic injury and enhance HBMECs viability subjected to OGD. In vivo and in vitro studies showed the mechanism might be related to the activation of PI3K/Akt signaling by phosphorylating Akt on Ser473. Pretreatment of SALD could alleviate BBB injury and improve the outcome of delayed treatment of tPA. These results provide evidence that SALD might be an effective adjuvant to reduce the complications induced by delayed tPA treatment for brain ischemia.

Rhodiola rosea L.: an herb with anti-stress, anti-aging, and immunostimulating properties for cancer chemoprevention

Purpose of review

Rhodiola rosea extracts have been used as a dietary supplement in healthy populations, including athletes, to non-specifically enhance the natural resistance of the body to both physical and behavior stresses for fighting fatigue and depression. We summarize the information with respect to the new pharmacological activities of Rhodiola rosea extracts and its underlying molecular mechanisms in this review article.

Recent findings

In addition to its multiplex stress-protective activity, Rhodiola rosea extracts have recently demonstrated its anti-aging, anti-inflammation, immunostimulating, DNA repair and anti-cancer effects in different model systems. Molecular mechanisms of Rhodiola rosea extracts's action have been studied mainly along with one of its bioactive compounds, salidroside. Both Rhodiola rosea extracts and salidroside have contrast molecular mechanisms on cancer and normal physiological functions. For cancer, Rhodiola rosea extracts and salidroside inhibit the mTOR pathway and reduce angiogenesis through down-regulation of the expression of HIF-1α/HIF-2α. For normal physiological functions, Rhodiola rosea extracts and salidroside activate the mTOR pathway, stimulate paracrine function and promote neovascularization by inhibiting PHD3 and stabilizing HIF-1α proteins in skeletal muscles. In contrast to many natural compounds, salidroside is water-soluble and highly bioavailable via oral administration and concentrated in urine by kidney excretion.

Summary

Rhodiola rosea extracts and salidroside can impose cellular and systemic benefits similar to the effect of positive lifestyle interventions to normal physiological functions and for anti-cancer. The unique pharmacological properties of Rhodiola rosea extracts or salidroside deserve further investigation for cancer chemoprevention, in particular for human urinary bladder cancer.

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.

Anti-Fatigue Effects of the Unique Polysaccharide Marker of Dendrobium officinale on BALB/c Mice

Dendrobium officinale extract shows potent anti-fatigue effects; however, the active substance responsible for these effects remains undetermined. A glucomannan with a huge molecular size of 730 kDa, called DOP, was identified as the unique authentication marker of this expensive herb. DOP exhibited immunomodulating effects on macrophages and lymphocytes in our previous study. Clinical reports also showed that people with fatigue syndrome have a disturbed immune system. Because DOP is the unique and dominant component of D. officinale, we hypothesize that DOP may also have anti-fatigue activity. The present study aims to evaluate the anti-fatigue activity of DOP on BALB/c mice, with Rhodiola rosea extract as a positive control. DOP and Rhodiola rosea extract were orally administered at doses of 50 mg/kg and 100 mg/kg, respectively, for four weeks, and the anti-fatigue activity of DOP on BALB/c mice was evaluated using the weight-loaded swimming test. The contents of lactic dehydrogenase (LDH), creatine phosphokinase (CK), triglyceride (TG), blood urea nitrogen (BUN), superoxide dismutase (SOD), malondialdehyde (MDA), lactic acid (LD), and glutathione peroxidase (GSH-Px) in serum, glycogen of liver and gastrocnemius muscle were also determined. Their effects on variability of T cells and B cells were determined by using tetrazolium compound (MTS) method. The weight-loaded swimming exercise caused fatigue syndrome, mainly including the decreases of serum SOD/GSH-Px and gastrocnemius glycogen, as well as the increases of LDH, BUN, MDA, CK, TG, and LD in serum. All of these indicators of fatigue were inhibited to a certain extent by both DOP and Rhodiola rosea extract; however, the effects of DOP were much stronger than those of Rhodiola rosea extract. Compared to the positive control, mice dosed with DOP showed increases in endurance, body weight, and food intake. Furthermore, DOP-feeding mice significantly increased the cell variability of T lymphocytes and B lymphocytes, compared with that of mice in control group. This study indicates that the unique and dominant polysaccharide DOP of D. officinale has stronger anti-fatigue activity than Rhodiola rosea extract. As such, DOP has promising potential for pharmaceutical development into health products to reduce fatigue.

Rhodiola rosea suppresses thymus T-lymphocyte apoptosis by downregulating tumor necrosis factor-α-induced protein 8-like-2 in septic rats

In recent years, several studies have shown that Rhodiola rosea can enhance cellular immunity and humoral immune function in mice, and thus, it has become a research hotspot. However, its underlying mechanism of action has remained elusive. The present study investigated whether Rhodiola rosea was able to downregulate the expression of tumor necrosis factor-α-inducible protein 8-like 2 (TIPE2), thereby inhibiting the expression of apoptotic genes, attenuating T-lymphocyte apoptosis and improving immunity in septic mice. A mouse model of caecal ligation and puncture (CLP)-induced sepsis was established, and animals in the treatment group were pre-treated with an intraperitoneal injection of Rhodiola rosea extract, while animals in the control group and sham-operated group were injected with an equivalent amount of normal saline. TIPE2, B-cell lymphoma 2 (Bcl-2), Fas and Fas ligand (FasL) mRNA and protein levels in thymic T cells were determined using reverse transcription quantitative polymerase chain reaction and western blot analysis, respectively. Furthermore, the thymus T-lymphocyte apoptosis rate, thymus T-lymphocyte count and thymus T-lymphocyte sub-sets were assessed using flow cytometry. Levels of T-helper cell type 1 (Th1) cytokines [Interleukin (IL)-2, IL-12 and interferon (IFN)-γ] and Th2 cytokines (IL-4 and IL-10) were determined using ELISA. The results showed that, compared to that in the CLP group, the expression of TIPE2, Fas and FasL in the treatment group was significantly decreased, while the expression of Bcl-2 was increased (P<0.05). The thymus lymphocyte count in the CLP group was significantly higher compared with that in the treatment group (P<0.05). Furthermore, the apoptotic rate of thymus T-lymphocytes in the treatment group was significantly lower than that in the CLP group (P<0.05). In addition, treatment with Rhodiola rosea rescued decreased in the counts of the CD3⁺ T and CD4⁺ T sub-sets of thymus T lymphocytes in the CLP group (P<0.05), while not affecting the increased levels of Th2 cytokines (IL-4 and IL-10) in the CLP group compared with those in the control groups. In addition, the Th1 cytokines (IL-12, IL-2 and IFN-γ) were significantly increased (P<0.05) in the CLP group, and treatment with Rhodiola rosea led to further increases. The thymus index of septic mice treated with Rhodiola rosea as well as their survival rate were improved as compared with those in the CLP group. These findings suggested that Rhodiola rosea has protective effects against sepsis by decreasing apoptosis, increasing Th1 cytokines and enhancing the host’s immunity via the regulation of TIPE2 expression.

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.

Effect of salidroside on lung injury by upregulating peroxisome proliferator-activated receptor γ expression in septic rats

Successful drug treatment for sepsis-related acute lung injury (ALI) remains a major clinical problem. Thus, the aim of the present study was to investigate the beneficial effects of salidroside on ameliorating cecal ligation and puncture (CLP)-induced lung inflammation. Rats underwent CLP surgery to induce ALI and 800 mg/kg salidroside (i.v.) was administered 24 h after the CLP challenge. Subsequently, biochemical changes in the blood and lung tissues, as well as morphological and histological alterations in the lungs, that were associated with inflammation and injury were analysed. CLP was shown to significantly increase the serum levels of plasma tumour necrosis factor-α and interleukin-6, -1β and-10. In addition, CLP increased pulmonary oedema, thickened the alveolar septa and caused inflammation in the lung cells. These changes were ameliorated by the administration of 800 mg/kg salidroside (i.v.) 24 h after the CLP challenge. This post-treatment drug administration also significantly attenuated the lipopolysaccharide-induced activation of nuclear factor-κβ and increased the release of peroxisome proliferator-activated receptor γ in the lung tissue. Therefore, salidroside administered following the induction of ALI by CLP significantly prevented and reversed lung tissue injuries. The positive post-treatment effects of salidroside administration indicated that salidroside may be a potential candidate for the management of lung inflammation in CLP-induced endotoxemia and septic shock.

Changes of cytokines during a spaceflight analog--a 45-day head-down bed rest

Spaceflight is associated with deregulation in the immune system. Head-down bed rest (HDBR) at -6° is believed to be the most practical model for examining multi-system responses to microgravity in humans during spaceflight. In the present study, a 45-day HDBR was performed to investigate the alterations in human immune cell distributions and their functions in response to various stimuli. The effect of countermeasure, Rhodiola rosea (RR) treatment, was also examined. A significant decrease of interferon-γ (IFN-γ) and interleukin-17 (IL-17) productions by activated T cells, increase of IL-1β and IL-18 by activated B and myeloid cells were observed during HDBR. The upregulation of serum cortisol was correlated with the changes of IL-1 family cytokines. In addition, a significant increase of memory T and B cell and regulatory T cells (Treg) were also detected. The uptake of RR further decreased IFN-γ level and slowed down the upregulation of IL-1 family cytokines. These data suggest that for prolonged HDBR and spaceflight, the decreased protective T cell immunity and enhanced proinflammatory cytokines should be closely monitored. The treatment with RR may play an important role in suppressing proinflammatory cytokines but not in boosting protective T cell immunity.

Salidroside improves behavioral and histological outcomes and reduces apoptosis via PI3K/Akt signaling after experimental traumatic brain injury

Background

Traumatic brain injury (TBI) induces a complex sequence of apopototic cascades that contribute to secondary tissue damage. The aim of this study was to investigate the effects of salidroside, a phenolic glycoside with potent anti-apoptotic properties, on behavioral and histological outcomes, brain edema, and apoptosis following experimental TBI and the possible involvement of the phosphoinositide 3-kinase/protein kinase B (PI3K)/Akt signaling pathway.

Methodology/Principal Findings

Mice subjected to controlled cortical impact injury received intraperitoneal salidroside (20, or 50 mg/kg) or vehicle injection 10 min after injury. Behavioral studies, histology analysis and brain water content assessment were performed. Levels of PI3K/Akt signaling-related molecules, apoptosis-related proteins, cytochrome C (CytoC), and Smac/DIABLO were also analyzed. LY294002, a PI3K inhibitor, was administered to examine the mechanism of protection. The protective effect of salidroside was also investigated in primary cultured neurons subjected to stretch injury. Treatment with 20 mg/kg salidroside_significantly improved functional recovery and reduced brain tissue damage up to post-injury day 28. Salidroside_also significantly reduced neuronal death, apoptosis, and brain edema at day 1. These changes were associated with significant decreases in cleaved caspase-3, CytoC, and Smac/DIABLO at days 1 and 3. Salidroside increased phosphorylation of Akt on Ser473 and the mitochondrial Bcl-2/Bax ratio at day 1, and enhanced phosphorylation of Akt on Thr308 at day 3. This beneficial effect was abolished by pre-injection of LY294002. Moreover, delayed administration of salidroside at 3 or 6 h post-injury reduced neuronal damage at day 1. Salidroside treatment also decreased neuronal vulnerability to stretch-induced injury in vitro.

Conclusions/Significance

Post-injury salidroside improved long-term behavioral and histological outcomes and reduced brain edema and apoptosis following TBI, at least partially via the PI3K/Akt signaling pathway.

Two new compounds from the roots of Rhodiola crenulata

Two new compounds, named (3R,5R,8R)-3-O-[α-l-arabinopyranosyl (1 → 6)-β-d-glucopyranosyl]-5-hydroxymegastigma-6,7-dien-9-one (1) and (1R)-1-O-(β-d-glucopyranosyl)-phenylethylene glycol (2), were isolated from the extract of Rhodiola crenulata. Their structures were determined on the basis of various spectroscopic methods, including IR, HR-ESI-MS, 1D and 2D NMR, and chemical evidences. The cytotoxicity of these two compounds was evaluated by using MTT method.