DCMQA, a caffeoylquinic acid derivative alleviates NMDA-induced neurotoxicity via modulating GluN2A and GluN2B-containing NMDA receptors in vitro.

Compound DCMQA (4, 5-O-dicaffeoyl-1-O-[4-malic acid methyl ester]-quinic acid) is a natural caffeoylquinic acid derivative isolated from Arctium lappa L. roots. Caffeoylquinic acid derivatives have been reported to possess neuroprotective effects through inhibiting oxidative stress and apoptosis in vitro. However, whether DCMQA exerts protective effects on N-methyl-D-aspartate (NMDA)-induced neurotoxicity and the underlying mechanism has not been elucidated. In this study, the results indicated that pretreatment of DCMQA prevented the loss of cell viability and attenuated the LDH leakage in SH-SY5Y cells exposed to NMDA. Hoechst 33342 staining and Annexin V-PI double staining illustrated that DCMQA suppressed NMDA-induced morphological damage and neuronal apoptosis. Moreover, DCMQA inhibited NMDA-mediated Ca2+ influx, excessive intracellular ROS generation and loss of mitochondrial membrane potential (MMP). Western blot analysis showed that DCMQA attenuated the Bax/Bcl-2 ratio, release of cytochrome c as well as expression of caspase-9 and caspase-3. Besides, DCMQA down-regulated GluN2B-containing NMDA receptors (NMDARs) and up-regulated GluN2A-containing NMDARs, promoted the disruption of nNOS and PSD95 as well as activation of CaMK II-α. Furthermore, computational docking study indicated that DCMQA possessed a good affinity for NMDARs. These results indicated that DCMQA protects SH-SY5Y cells against NMDA-induced neuronal damage. In addition, the underlying mechanisms of DCMQA-mediated neuroprotection are associated with modulating NMDARs and disruption of nNOS-PSD95 as well as the activation of CaMK II-α.

Yang Y ，Gao H ，Liu W ，Jiang X ，Shen Z ，Li X ，Ren T ，Xu Z ，Cheng G ，Zhao Q ... -  《-》

Compound MQA, a Caffeoylquinic Acid Derivative, Protects Against NMDA-Induced Neurotoxicity and Potential Mechanisms In Vitro.

Compound MQA (1,5-O-dicaffeoyl-3-O-[4-malic acid methyl ester]-quinic acid) is a natural derivative of caffeoylquinic acid isolated from Arctium lappa L. roots. However, we know little about the effects of MQA on the central nervous system. This study aims to investigate the neuroprotective effects and underlying mechanisms of MQA against the neurotoxicity of N-methyl-d-aspartate (NMDA). Pretreatment with MQA attenuated the loss of cell viability after SH-SY5Y cells treated with 1 mM NMDA for 30 min by MTT assay. Hoechst 33342 and Annexin V-PI double staining showed that MQA inhibited NMDA-induced apoptosis. In addition to preventing Ca(2+) influx, the potential mechanisms are associated with increases in the Bcl-2/Bax ratio, attenuation of cytochrome c release, caspase-3, caspase-9 activities, and expressions. Also, MQA inhibited NMDA-induced phosphorylation of ERK1/2, p38, and JNK1/2. Furthermore, deactivation of CREB, AKT, and GSK-3β, upregulation of GluN2B-containing NMDA receptors (NMDARs), and downregulation of GluN2A-containing NMDARs were significantly reversed by MQA treatment. Computational docking simulation indicates that MQA possesses a well affinity for NMDARs. The protective effects of MQA against NMDA-induced cell injury may be mediated by blocking NMDARs. The potential mechanisms are related with mitochondrial apoptosis, ERK-CREB, AKT/GSK-3β, p38, and JNK1/2 pathway.

Tian X ，An L ，Gao LY ，Bai JP ，Wang J ，Meng WH ，Ren TS ，Zhao QC ... -  《-》

Arctium lappa L. roots ameliorates cerebral ischemia through inhibiting neuronal apoptosis and suppressing AMPK/mTOR-mediated autophagy.

Arctium lappa L. roots are very popular cultivated vegetables, which possesses various pharmacological activities. Our previous studies have demonstrated that Arctium lappa L. roots exerted protective effects against H2O2, glutamate and N-methyl-D-aspartic acid (NMDA)-induced neuronal injury in vitro. However, whether Arctium lappa L. roots could prevent against cerebral ischemia and the underlying mechanism remain unclear. The objective of the present study was to investigate the neuroprotective effects of ethyl acetate extract of Arctium lappa L. roots (EAL) and the active ingredient 4,5-O-dicaffeoyl-1-O-[4-malic acid methyl ester]-quinic acid (DCMQA) in EAL against cerebral ischemia and explore the underlying mechanism. The neuroprotective effects of EAL and DCMQA were investigated in rats with permanent middle cerebral artery occlusion (MCAO) and in oxygen glucose deprivation/reoxygenation (OGD/R)-stimulated SH-SY5Y cells, respectively. The infarct volume, brain edema and neurological deficits were measured following MCAO. TUNEL and Nissl staining were performed to detect neuronal loss and apoptosis of neurons in rat brains. Cell survival was measured by MTT and LDH assay. In addition, reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) levels were determined by DCFH-DA and JC-1 fluorescent probe, respectively. Hoechst 33342 staining and Annexin V-FITC/PI double staining were performed to evaluate neuronal apoptosis. The expression levels of proteins were evaluated by western blot. EAL reduced brain infarct volume, ameliorated brain edema and improved neurological deficits in MCAO rats. In addition, EAL inhibited oxidative stress and inflammatory responses following MCAO. Besides, active compound DCMQA alleviated cytotoxicity as well as inhibited over-production of intracellular ROS and loss of MMP induced by OGD/R in SH-SY5Y cells. Moreover, EAL and DCMQA inhibited apoptosis by decreasing the expressions of pro-apoptotic proteins including bax, cytochrome c and cleaved caspase-3 while promoting the bcl-2 expression in MCAO rats and OGD/R-stimulated neurons, respectively. In addition, DCMQA suppressed the production of autophagosomes and down-regulated expression of Beclin 1 and LC3. Furthermore, inhibiting AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) signaling pathway contributed to DCMQA-mediated suppression of autophagy induced by OGD/R. Our findings demonstrate that Arctium lappa L. roots protect against cerebral ischemia through inhibiting apoptosis and AMPK/mTOR-mediated autophagy in vitro and in vivo, providing a theoretical basis for the development of CQAs in Arctium lappa L. roots as neuroprotective drugs for the prevention and treatment of ischemic stroke.

Yang Y ，Gao H ，Liu W ，Liu X ，Jiang X ，Li X ，Wu Q ，Xu Z ，Zhao Q ... -  《-》

Pretreatment of MQA, a caffeoylquinic acid derivative compound, protects against H(2)O(2)-induced oxidative stress in SH-SY5Y cells.

Tian X ，Gao L ，An L ，Jiang X ，Bai J ，Huang J ，Meng W ，Zhao Q ... -  《-》

Lyciumamide A, a dimer of phenolic amide, protects against NMDA-induced neurotoxicity and potential mechanisms in vitro.

Gao K ，Liu M ，Li Y ，Wang L ，Zhao C ，Zhao X ，Zhao J ，Ding Y ，Tang H ，Jia Y ，Wang J ，Wen A ... -  《-》