Shih-Yu Lee

Rhodiola crenulata Extract Alleviates Hypoxic Pulmonary Edema in Rats.

Sudden exposure of nonacclimatized individuals to high altitude can easily lead to high altitude illnesses. High altitude pulmonary edema (HAPE) is the most lethal form of high altitude illness. The present study was designed to investigate the ability of Rhodiola crenulata extract (RCE), an herbal medicine traditionally used as an antiacute mountain sickness remedy, to attenuate hypoxia-induced pulmonary injury. Exposure of animals to hypobaric hypoxia led to a significant increase in pathological indicators for pulmonary edema, including the lung water content, disruption of the alveolar-capillary barrier, and protein-rich fluid in the lungs. In addition, hypobaric hypoxia also increased oxidative stress markers, including (ROS) production, (MDA) level, and (MPO) activity. Furthermore, overexpression of plasma (ET-1), (VEGF) in (BALF), and (HIF-1α) in lung tissue was also found. However, pretreatment with RCE relieved the HAPE findings by curtailing all of the hypoxia-induced lung injury parameters. These findings suggest that RCE confers effective protection for maintaining the integrity of the alveolar-capillary barrier by alleviating the elevated ET-1 and VEGF levels; it does so by reducing hypoxia-induced oxidative stress. Our results offer substantial evidence to support arguments in favor of traditional applications of Rhodiola crenulata for antihigh altitude illness.

Rhodiola crenulata extract suppresses hepatic gluconeogenesis via activation of the AMPK pathway.

BACKGROUND Rhodiola, a popular herb, has been used for treating high altitude sicknesses, depression, fatigue, and diabetes. However, the detailed mechanisms by which Rhodiola crenulata functions in the liver need further clarification. PURPOSE The current study was designed to examine the effects of Rhodiola crenulata root extract (RCE) on hepatic glucose production. METHODS Human hepatoma HepG2 cells were treated with RCE for 6 h. Glucose production, the expression level of p-AMPK, and the expression of key gluconeogenic genes were measured. The effects of RCE were also studied in Sprague-Dawley (SD) rats. The efficacy and underlying mechanism of RCE in the liver were examined. RESULTS RCE significantly suppressed glucose production and gluconeogenic gene expression in HepG2 cells while activating the AMPK signaling pathway. Interestingly, RCE-suppressed hepatic gluconeogenesis was eliminated by an AMPK-specific inhibitor, but not by the PI3K/AKT-specific inhibitor. In addition, oral administration of RCE significantly increased phosphorylated AMPK levels and inhibited gluconeogenic gene expression in the rat liver. Furthermore, RCE treatment also decreased plasma glucose concentration in rats. CONCLUSION We present in vitro and in vivo evidence that RCE might exert the glucose-lowering effect partly by inhibiting hepatic gluconeogenesis through activating the AMPK signaling pathway. These findings provide evidence that Rhodiola crenulata may be helpful for the management of type II diabetes.

Rhodiola crenulata Attenuates High Glucose Induced Endothelial Dysfunction in Human Umbilical Vein Endothelial Cells

Rhodiola crenulata root extract (RCE), a traditional Chinese medicine, has been shown to regulate glucose and lipid metabolism via the AMPK pathway in high glucose (HG) conditions. However, the effect of RCE on HG-induced endothelial dysfunction remains unclear. The present study was designed to examine the effects and mechanisms of RCE against hyperglycemic insult in endothelial cells. Human umbilical vein endothelial cells (HUVECs) were pretreated with or without RCE and then exposed to 33[Formula: see text]mM HG medium. The cell viability, nitrite production, oxidative stress markers, and vasoactive factors, as well as the mechanisms underlying RCE action, were then investigated. We found that RCE significantly improved cell death, nitric oxide (NO) defects, and oxidative stress in HG conditions. In addition, RCE significantly decreased the HG-induced vasoactive markers, including endothelin-1 (ET-1), fibronectin, and vascular endothelial growth factor (VEGF). However, the RCE-restored AMPK-Akt-eNOS-NO axis and cell viability were abolished by the presence of an AMPK inhibitor. These findings suggested that the protective effects of RCE were associated with the AMPK-Akt-eNOS-NO signaling pathway. In conclusion, we showed that RCE protected endothelial cells from hyperglycemic insult and demonstrated its potential for use as a treatment for endothelial dysfunction in diabetes mellitus.

Melaleuca alternifolia Induces Heme Oxygenase-1 Expression in Murine RAW264.7 Cells through Activation of the Nrf2-ARE Pathway

Melaleuca alternifolia concentrate (MAC) is the refined essential oil of the Australian native plant Melaleuca alternifolia. MAC has been reported to suppress the production of pro-inflammatory cytokines in both murine RAW264.7 macrophages and human monocytes stimulated with lipopolysaccharide (LPS). However, the mechanisms involved in this effect remain unclear. This study aims to delineate the molecular mechanisms that drive the anti-inflammatory activity of MAC and its active component, terpinen-4-ol, in macrophages. The effects of MAC on RAW264.7 cells were studied using western blotting, real-time PCR, an electrophoretic mobility shift assay (EMSA), and NF-[Formula: see text]B luciferase reporter assays. Our results showed that MAC significantly increased both the mRNA and protein levels of heme oxygenase-1 (HO-1) via p38 and JNK MAPK activation. In addition, we showed that MAC significantly increased the activation and nuclear translocation of NF-E2-related factor 2 (Nrf2), a key transcription factor regulating HO-1 induction. MAC was also associated with significant inhibition of iNOS expression, NO production, and NF-[Formula: see text]B activation. HO-1 was required for these anti-inflammatory effects as tin protoporphyrin IX (SnPPIX), an HO-1 inhibitor, abolished the effects of MAC on LPS-induced iNOS, NO, and NF-[Formula: see text]B activation. Our results indicate that MAC induces HO-1 expression in murine macrophages via the p38 MAPK and JNK pathways and that this induction is required for its anti-inflammatory activity.

Rhodiola crenulata Attenuates γ-Ray Induced Cellular Injury via Modulation of Oxidative Stress in Human Skin Cells

Skin injury is a major complication during radiation therapy and is associated with oxidative damage to skin cells. An effective and safe radioprotectant to prevent this skin damage is still unavailable. The Rhodiola crenulata root extract (RCE) has been reported to be a free radical scavenger and a potent anti-oxidant in both in vitro and in vivo models. In the current study, we investigated the effects of RCE on ionizing radiation-induced skin injury and its underlying mechanisms. HaCaT cells - a non-cancerous skin cell line together with HepG2, Caco2, A549, and OECM cancer cell lines - were pre-treated with RCE for 24[Formula: see text]h followed by exposure to 15 Gy using Caesium-137 as a γ-ray source. The cell viability was measured. In HaCaT cells, oxidative stress markers, cellular apoptosis pathways, matrix metalloproteinases (MMPs), and pro-inflammatory cytokine gene expression were studied. We found that RCE significantly protected HaCaT cells, but not cancer cells from the loss of viability induced by exposure to ionizing radiation. RCE attenuated radiation-induced oxidative stress markers, cell apoptosis, MMP levels, and expression of cytokine genes. RCE also limited the induction of p53 and p21 by radiation exposure. These findings indicate that RCE may selectively protect the skin cells from ionizing radiation without altering its ability to kill cancer cells. Therefore, we suggest that RCE or its derivatives could serve as a novel radioprotective therapy.

In Vitro Anticancer Activity and Structural Characterization of Ubiquinones from Antrodia cinnamomea Mycelium

Two new ubiquinones, named antrocinnamone and 4-acetylantrocamol LT3, were isolated along with six known ubiquinones from Antrodia cinnamomea (Polyporaceae) mycelium. The developed HPLC analysis methods successfully identified eight different ubiquinones, two benzenoids, and one maleic acid derivative from A. cinnamomea. The ubiquinones 1–8 exhibited potential and selective cytotoxic activity against three human cancer cell lines, with IC50 values ranging from 0.001 to 35.883 μM. We suggest that the different cytotoxicity levels were related to their chemical structures, especially the 4-hydroxycyclohex-2-enone ring and the presence of a free hydroxyl group in the side chain. The suppression by 4-acetylantrocamol LT3 stopped the cell cycle at the beginning of the G2-M phase thus making the cell cycle arrest at the sub-G1 phase as compared with control cells.

Astragaloside VI and cycloastragenol-6-O-beta-D-glucoside promote wound healing in vitro and in vivo

BACKGROUND Astragalus genus includes most of the common, historical herbal medicines that have various applications in Asian countries. However, clinical data and mechanistic insights into their actions are still lacking. PURPOSE In this study, we aimed to examine the effects of astragalosides on wound healing in vitro and in vivo, as well as the underlying mechanisms of these actions. METHODS The wound healing activity of astragalosides was investigated in human HaCaT keratinocytes, human dermal fibroblast (HDF) cells, and murine models of wound healing. RESULTS All eight astragalosides studied enhanced epidermal growth factor receptor (EGFR) activity in HaCaT cells. Among them, astragaloside VI (AS-VI) showed the strongest EGFR activation. Consistently, AS-VI and cycloastragenol-6-O-beta-D-glucoside (CMG), which is the major metabolite of astragalosides, enhanced extracellular signal-regulated kinase (ERK) activity in a concentration-dependent manner. In agreement, both compounds induced EGFR-dependent cell proliferation and migration in HaCaT and HDF cells. In addition, we showed that AS-VI and CMG accelerated the healing of both sterile and infected wounds in vivo. These effects were associated with increased angiogenesis in the scar tissue. CONCLUSION AS-VI and CMG increased the proliferation and migration of skin cells via activation of the EGFR/ERK signalling pathway, resulting in the improvement of wound healing in vitro and in vivo. These findings indicate the therapeutic potential of AS-VI and CMG to accelerate wound healing; additionally, they suggest the mechanistic basis of this activity.

Protective Effects of Rhodiola Crenulata Extract on Hypoxia-Induced Endothelial Damage via Regulation of AMPK and ERK Pathways

Rhodiola crenulata root extract (RCE) has been shown to possess protective activities against hypoxia both in vitro and in vivo. However, the effects of RCE on response to hypoxia in the endothelium remain unclear. In this study, we aimed to examine the effects of RCE in endothelial cells challenged with hypoxic exposure and to elucidate the underlying mechanisms. Human umbilical vein endothelial cells were pretreated with or without RCE and then exposed to hypoxia (1% O2) for 24 h. Cell viability, nitric oxide (NO) production, oxidative stress markers, as well as mechanistic readouts were studied. We found that hypoxia-induced cell death, impaired NO production, and oxidative stress. These responses were significantly attenuated by RCE treatment and were associated with the activation of AMP-activated kinase and extracellular signal-regulated kinase 1/2 signaling pathways. In summary, we showed that RCE protected endothelial cells from hypoxic insult and suggested that R. crenulata might be useful for the prevention of hypoxia-associated vascular dysfunction.

TAZ is Associated with Poor Osteoblast Differentiation of Mesenchymal Stem Cells Under Simulated Microgravity

Background: Exposure to microgravity (MG) leads to many varieties of physiological alterations, including bone loss. Most studies concur that the impaired osteoblast differentiation of mesenchymal stem cells (MSCs) plays an important role in this bone loss. However, the detailed signaling mechanisms underlying the MG-induced bone loss remain to be further clarified. Materials and Methods: We utilized a rotary cell culture system (RCCS) to study the role of transcriptional coactivator with PDZ-binding motif (TAZ) in simulated MG. Cells were obtained from the calvarial bone of 5-d old Balb/c mice littermates. The phenotype of the MSCs was confirmed by positive expression of Sca-1 and CD29, and negative for CD45. MSCs were cultured in osteo-induction medium in order to promote differentiation towards osteoblasts (OSTs). Results: Upon exposure to MG for 7 days, the abundance of Runx2 was significantly reduced to 0.33 and 0.2-fold in MSCs and OSTs, respectively. In contrast, PPARγ2 was significantly enhanced to 3.8 and 3.0-fold in response to MG in MSCs and OSTs, respectively. TAZ mRNA is decreased to 0.22- and 0.08-fold as compared to normal gravity (NG) in both MSCs and OSTs, respectively. Similarly, the TAZ protein level was also significantly decreased to 0.4-fold in MSCs and to 0.2-fold in OSTs. Moreover, we showed that MG indeed disrupted the interaction of TAZ and Runx2, which disturbed osteoblast-related gene expression. Conclusions: We show for the first time that the TAZ is associated with MG-induced impairment of osteoblast differentiation. Our results also suggest that TAZ plays an important role in MG-induced bone loss.