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Wang R.,Jiangxi University of Traditional Chinese Medicine | Zhao J.,Jinan University | Zhang L.,Jinan University | Peng L.,Jinan University | And 4 more authors.
International Journal of Molecular Sciences | Year: 2016

CHR20 and CHR21 are a pair of stable diastereoisomers derived from genipin. These stereoisomers are activators of neuronal nitric oxide synthase (nNOS) and endothelial nitric oxide synthase (eNOS). In the rat retinal ganglion (RGC-5) cell model these compounds are non-toxic. Treatment of RGC-5 with 750 μM of sodium nitroprusside (SNP) produces nitrosative stress. Both genipin derivatives, however, protect these cells against SNP-induced apoptic cell death, although CHR21 is significantly more potent than CHR20 in this regard. With Western blotting we showed that the observed neuroprotection is primarily due to the activation of protein kinase B (Akt)/eNOS and extracellular signal-regulated kinase (ERK1/2) signaling pathways. Therefore, LY294002 (a phosphatidylinositol 3-kinase (PI3K) inhibitor) or PD98059 (a MAPK-activating enzyme inhibitor) abrogated the protective effects of CHR20 and CHR21. Altogether, our results show that in our experimental setup neuroprotection by the diasteromeric pair is mediated through the PI3K/Akt/eNOS and ERK1/2 signaling pathways. Further studies are needed to establish the potential of these compounds to prevent ntric oxide (NO)-induced toxicity commonly seen in many neurodegenerative diseases. © 2016 by the authors; licensee MDPI, Basel, Switzerland.

Wang R.,Jiangxi University of Traditional Chinese Medicine | Peng L.,Jinan University | Zhao J.,Jinan University | Zhang L.,Jinan University | And 4 more authors.
International Journal of Molecular Sciences | Year: 2015

Gardenamide A (GA) protects the rat retinal ganglion (RGC-5) cells against cell apoptosis induced by H2O2. The protective effect of GA was completely abrogated by the specific phosphoinositide 3-kinase (PI3K) inhibitor LY294002, and the specific protein kinase B (Akt) inhibitor Akt VIII respectively, indicating that the protective mechanism of GA is mediated by the PI3K/Akt signaling pathway. The specific extracellular signal-regulated kinase (ERK1/2) inhibitor PD98059 could not block the neuroprotection of GA. GA attenuated the levels of reactive oxygen species (ROS) and malondialdehyde (MDA) induced by H2O2. Western blotting showed that GA promoted the phosphorylation of ERK1/2, Akt and endothelial nitric oxide synthase (eNOS), respectively, and effectively reversed the H2O2-inhibited phosphorylation of these three proteins. LY294002 completely inhibited the GA-activated phosphorylation of Akt, while only partially inhibiting eNOS. This evidence implies that eNOS may be activated directly by GA. PD98059 attenuated only partially the GA-induced phosphorylation of ERK1/2 with/without the presence of H2O2, indicating that GA may activate ERK1/2 directly. All these results put together confirm that GA protects RGC-5 cells from H2O2 insults via the activation of PI3K/Akt/eNOS signaling pathway. Whether the ERK1/2 signaling pathway is involved requires further investigations. © 2015 by the authors; licensee MDPI, Basel, Switzerland.

Zhao J.,Jinan University | Peng L.,Jinan University | Zheng W.,University of Macao | Wang R.,Jiangxi University of Traditional Chinese Medicine | And 4 more authors.
International Journal of Molecular Sciences | Year: 2015

Two amantadine (ATD)-gardenamide A (GA) ligands have been designed and synthesized. The bonding of ATD with GA through a methylene carbonyl brigde (L1) enhances the neuroprotective effect against corticosterone (CORT)-induced impairments in PC12 cells; while the bonding through a succinyl brigde (L2) does not. L1 reduces the level of reactive oxygen species (ROS) and cell apoptosis generated by CORT. It restores CORT-changed cell morphology to a state that is closed to normal PC12 cells. One mechanism of L1 to attenuate CORT-induced cell apoptosis is through the adjustment of both caspase-3 and Bcl-2 proteins. Like GA, both nNOS and eNOS might be involved in the neuroprotective mechanism of L1. All the evidences suggest that L1 may be a potential agent to treat depression. © 2015 by the authors; licensee MDPI, Basel, Switzerland.

Yang M.-X.,Jinan University | Yang M.-X.,Zhongshan Torch Polytechnic College | Liang Y.-G.,UNO Scientific Co. | Chen H.-R.,Jinan University | And 3 more authors.
Chinese Traditional and Herbal Drugs | Year: 2014

Objective: To investigate the chemical constituents from the leaves of wild Aquilaria sinensis. Methods: The powder of the dried leaves was percolated with 70% acetone. Various chromatographic methods were employed to isolate the compounds and their structures were established by spectroscopic analysis. Results: Thirteen compounds were isolated and identified as 6-E-octadecenoic acid (1), ethyl linoleate (2), apiolin-7, 4'-dimethyl ether (3), 4-cyanobenzaldehyde (4), luteolin-7, 3', 4'-trimethyl ether (5), genkwanin (6), p-phthalic acid di (4-octyl) ester (7), 6-hydroxy-7, 4'-dimethoxyflavone (8), 5-hydroxy-7, 2', 4', 5'- tetramethoxyflavone (9), 5, 4'-dihydroxy-7, 3'-dimethoxyflavone (10), quercetin (11), kaempferol (12), and 4-hydroxybenzoic acid (13). Conclusion: Thirteen compounds have been identified from wild A. sinensis leaves. Compounds 4, 8, and 9 are firstly isolated from the plants of Thymelaeaceae.

Yang Z.-Y.,Jinan University | Lu D.-Y.,Jinan University | Yao S.,University of Sichuan | Zhang R.-R.,Jinan University | And 3 more authors.
Journal of Food and Drug Analysis | Year: 2013

An HPLC-DAD-ESI-MS method was employed for the chromatographic fingerprint analysis of Cistanche deserticola (Roucongrong in Chinese). Eleven batches of samples were analyzed to establish the reference fingerprint of C. deserticola. Eight peaks in the fingerprint of all the 11 batches of samples were assigned as "characteristic peaks", and identified by comparing their retention time and mass spectra with those of the reference substances. The similarity of the 11 batches of samples was evaluated by a simulative mean chromatogram. The results indicated that the samples from different origins shared similar HPLC fingerprints. In addition, an HPLC-DAD method was developed for simultaneous determination of the contents of the eight compounds in C. deserticola. All eight compounds showed good linear regression (R2 > 0.9998) within test ranges and the recovery of the method was in the range of 93.65-109.79%, indicating that the developed method combining chromatographic fingerprint with quantification analysis could readily be applied for the quality control of C. deserticola.

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