ABSTRACT
Osteoporosis development is closely associated with oxidative stress and reactive oxygen species (ROS). Taurine has potential antioxidant effects, but its role in osteoblasts is not clearly understood. The aim of this study was to determine the protective effects and mechanisms of actions of taurine on hydrogen peroxide (H₂O₂)-induced oxidative stress in osteoblast cells. UMR-106 cells were treated with taurine prior to H₂O₂ exposure. After treatment, cell viability, apoptosis, intracellular ROS production, malondialdehyde content, and alkaline phosphate (ALP) activity were measured. We also investigated the protein levels of β-catenin, ERK, CHOP and NF-E2-related factor 2 (Nrf2) along with the mRNA levels of Nrf2 downstream antioxidants. The results showed that pretreatment of taurine could reverse the inhibition of cell viability and suppress the induced apoptosis in a dose-dependent manner: taurine significantly reduced H₂O₂-induced oxidative damage and expression of CHOP, while it induced protein expression of Nrf2 and β-catenin and activated ERK phosphorylation. DKK1, a Wnt/β-catenin signaling inhibitor, significantly suppressed the taurine-induced Nrf2 signaling pathway and increased CHOP. Activation of ERK signaling mediated by taurine in the presence of H₂O₂ was significantly inhibited by DKK1. These data demonstrated that taurine protects osteoblast cells against oxidative damage via Wnt/β-catenin-mediated activation of the ERK signaling pathway.
Subject(s)
Antioxidants , Apoptosis , Cell Survival , Hydrogen Peroxide , Hydrogen , Malondialdehyde , NF-E2-Related Factor 2 , Osteoblasts , Osteoporosis , Oxidative Stress , Phosphorylation , Reactive Oxygen Species , RNA, Messenger , TaurineABSTRACT
Objective To establish fingerprints of cultured Cordyceps Militaris, Cordyceps Sinensis and Fermental Cordyceps.Methods Water soluble components in Cordyceps Sinensis were extracted by ultrasonic method. The characteristic fingerprints were established by HPLC, with Agilent ZORBAX SB-Aq (4.6 mm × 250 mm, 5μm) as column and acetonitrile (A)-0.04 mol/L KH2PO4 (B) as mobile phase;gradient elution (0-16 min, 0%A;16-38 min, 0→10%A;38-58 min, 10%→15%A;58-65 min, 15→0%A);the flow rate was 1.0 mL/min;column temperature was 25℃;the detection wavelength was 260 nm;the injection volume was 20μL. The HPLC characteristic fingerprint of mycelium was developed, and the components of adenosine, uridine, guanosine, inosine, uracil, adenine and cordycepin were identified and compared.Results This method is with high degree of precision, good repeatability and stability. With adenosine as reference peak, similarity of 11 batches of Cordyceps Sinensis collected from different habitats, 10 batches of cultured Cordyceps Militarise and 12 batches of Fermental Cordyceps were 0.889-0.982, 0.781-0.980 and 0.502-0.970, respectively.Conclusion There were good similarities between the standard fingerprint and each fingerprint of the eleven samples of Cordyceps Sinensis. There were low similarities between the standard fingerprint and each fingerprint of the ten samples of cultured Cordyceps Militaris and the twelve samples of Fermental Cordyceps. This method can be reference base for the evaluation of quality of cultured Cordyceps Militaris and Cordyceps Sinensis.
ABSTRACT
Objective To develop an HPLC method for determination of content of ergosterol in cultured Cordyceps militaris and natural Cordyceps sinensis. Methods Diamonsil C18(2) column (150 mm×4.6 mm, 5 μm) was used, with methanol-water (98∶2) as mobile phase, column temperature of 25 ℃ , flow rate of 1.0 mL/min, and detection wavelength of 280 nm. Results The linear range of ergosterol was 0.197 7-3.954 9 μg (r=1.000), and avarage recovery rate was 99.51%, RSD was 0.56% (n=9). Conclusion This method is effective, sensitive and accurate with high repeatability and stability, which is helpful for the determination of ergosterol in the cultured Cordyceps and natural Cordyceps.