Anti-neuroinflammatory effects of DPTP, a novel synthetic clovamide derivative in in vitro and in vivo model of neuroinflammation.

Neuroinflammation is one of the critical pathological mechanisms influencing various neurodegenerative disorders. Most of the neurodegenerative diseases involve over-activation of microglial cells contributing to the demise of neurons. The objective of the current study is to evaluate the anti-inflammatory effect of novel synthetic clovamide derivative on the suppression of microglial activation in an in vitro and in vivo model of neuroinflammation. We have used lipopolysaccharide (LPS) to induce an inflammatory response in murine BV-2 microglial cells. Molecular tools like immunocytochemistry and immunoblotting were used to study the activity of novel synthetic clovamide derivative to inhibit inflammation induced by LPS in microglial cells. In in vivo experiments, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) intoxicated mouse model of neuroinflammation was developed to investigate the anti-neuroinflammatory effects of DPTP [3-(3,4-Dihydroxy-phenyl)-2-[4-(3-trifluoromethylphenyl)-but-2-enoylamino]-propionic acid methyl ester]. DPTP was observed to reduce the proinflammatory response in BV-2 cells induced by LPS. Further investigation revealed that DPTP attenuated phosphorylation of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK), which was accompanied by a decrease in nuclear translocation of nuclear factor-κB (NF-κB) in LPS-treated BV2 microglia. Moreover, prophylactic treatment with DPTP (20mg/kg) for 7 days suppressed MPTP induced glial activation and behavioral impairment. Overall, our findings suggested that, DPTP exerts anti-neuroinflammatory effects against activated microglia in an in vitro and in vivo model and hence might be a promising therapeutic agent for alleviating the evolvement of neurodegenerative diseases associated with microglial activation.

Lim HW ，Park JI ，More SV ，Park JY ，Kim BW ，Jeon SB ，Yun YS ，Park EJ ，Yoon SH ，Choi DK ... -  《-》

Attenuation of neuroinflammatory responses and behavioral deficits by Ligusticum officinale (Makino) Kitag in stimulated microglia and MPTP-induced mouse model of Parkinson's disease.

Ligusticum officinale (Makino) Kitag (L. officinale) is one of the important traditional herbs used in traditional Oriental medicine for the treatment of various disorders including pain and inflammation. However, there is limited scientific basis for its activity and mechanism in brain inflammation. This study aimed to evaluate the effects of L. officinale on microglia-mediated neuroinflammation and behavioral impairments using in vitro cellular and in vivo mouse model of PD, as well as investigate the molecular mechanisms involved including the finger printing analysis of its ethanol extract. Lipopolysaccharide (LPS) was used to stimulate BV-2 microglial cells. The changes in neuroinflammatory expressional levels were measured by Western blotting and immunofluorescence techniques. 1-methyl-4 phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-intoxicated mice model of PD was developed to evaluate the behavioral impairments and the brain tissues were used for immunohistochemical studies. High performance liquid chromatography (HPLC) technique was performed for finger printing analysis of L. officinale extract used in the study. L. officinale significantly attenuated the LPS-stimulated increase in inflammatory mediators in BV-2 cells. L. officinale also inhibited the LPS-induced activation of nuclear factor-kappa beta by blocking the degradation of IκB-α and suppressing the increase in p38-mitogen-activated protein kinase phosphorylation in BV-2 cells. Furthermore, L. officinale exhibited significant antioxidant properties by inhibiting the 1-diphenyl-2-picrylhydrazyl radicals. An in vivo evaluation in MPTP (20mg/kg, four times, 1 day, i.p.) intoxicated mice resulted in brain microglial activation and significant behavioral deficits. Prophylactic treatment with L. officinale prevented microglial activation and attenuated PD-like behavioral changes as assessed by the pole test. HPLC finger printing analysis revealed that L. officinale extract contained ferulic acid (FA) as one of the major constituents compared with reference standard. FA also inhibited the LPS-stimulated excessive release of NO and suppressed the increased the expressional levels of proinflammatory mediators in BV-2 microglia. The findings observed in this study indicated that L. officinale extract significantly attenuated the neuroinflammatory processes in stimulated microglia and restored the behavioral impairments in a mouse model of PD providing a scientific basis for its traditional claims.

Kim BW ，Koppula S ，Park SY ，Kim YS ，Park PJ ，Lim JH ，Kim IS ，Choi DK ... -  《-》

α-Asarone attenuates microglia-mediated neuroinflammation by inhibiting NF kappa B activation and mitigates MPTP-induced behavioral deficits in a mouse model of Parkinson's disease.

The selective loss of dopaminergic neurons in Parkinson's disease (PD) is associated with microglial activation. Therefore, the importance of early therapeutic intervention to inhibit microglial activation would be an effective strategy to alleviate the progression of PD. α-Asarone, an active compound found in Araceae and Annonaceae plant species has been used to improve various disease conditions including central nervous system disorders. In the present study the in vitro and in vivo therapeutic effects of α-asarone isolated from the rhizome of Acorus gramineus Solander was evaluated on microglia-mediated neuroinflammation and neuroprotection. Lipopolysaccharide (LPS)-stimulated BV-2 microglial cells were used to evaluate in vitro effects. 1-methyl-4 phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-induced mouse model of PD was developed to study the neuroprotective effects of α-asarone in vivo. The results indicated that α-asarone significantly attenuated the LPS-stimulated increase in neuroinflammatory responses and suppressed pro-inflammatory cytokine production in BV-2 cells. Mechanistic study revealed that α-asarone inhibited the LPS-stimulated activation via regulation of nuclear factor kappa-B by blocking degradation of inhibitor kappa B-alpha signaling in BV-2 microglial cells. In in vivo studies, MPTP intoxication to mice resulted in brain microglial activation and significant behavioral deficits. Prophylactic treatment with α-asarone suppressed microglial activation and attenuated PD-like behavioral impairments as assessed by the Y-maze and pole tests. Taken together, these data demonstrate that α-asarone is a promising neuroprotective agent that should be further evaluated and developed for future prevention and treatment of microglia-mediated neuroinflammatory conditions including PD.

Kim BW ，Koppula S ，Kumar H ，Park JY ，Kim IW ，More SV ，Kim IS ，Han SD ，Kim SK ，Yoon SH ，Choi DK ... -  《-》

Tanshinone I selectively suppresses pro-inflammatory genes expression in activated microglia and prevents nigrostriatal dopaminergic neurodegeneration in a mouse model of Parkinson's disease.

Radix Salviae Miltiorrhizae, known as Danshen, is a well-known traditional Chinese herb which has been used extensively for the treatment of various diseases, including cardiovascular and cerebrovascular disease and neurodegenerative diseases for thousands of years. Tanshinone I is one of major bioactive flavonoids of Radix Salviae Miltiorrhizae. Modulation of microglial over-reaction may represent a therapeutic target to alleviate the progression of neurodegenerative diseases. Here, we tested the effect of Tanshinone I on neuro-inflammation and whether it can provide neuroprotection through inhibition of neuro-inflammation. The effects of Tanshinone I on the production and/or mRNA expression of pro-inflammatory and anti-inflammatory factors in lipopolysaccharide(LPS)-induced BV-2 microglia cells were tested by Griess reaction, enzyme-linked immunosorbent assay (Elisa) or real time polymerase chain reaction. Activation of nuclear factor κ B (NF-κB) was measured by the nuclear translocation p65 and DNA binding activity. A model of Parkinson׳s disease was established by treatment of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in C57BL/6 mice. The effect of Tanshinone I on the behavioral changes, dopamine and its metabolites levels, expression of tyrosine hydroxylase (TH) and IBA-1, production of cytokines in the midbrain were investigated by the rotarod test, high-performance liquid chromatography (HPLC)-ECD, immunohistochemistry and Elisa. 1-methyl-4-phenylpyridinium (MPP+) concentration was tested by HPLC. Liver toxicity was determined by biochemical assay and histochemistry. We found that the productions and/or expressions of several pro-inflammatory M1 factors such as nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-6 were highly suppressed by Tanshinone I in LPS-induced microglia. Interestingly, it did not affect the enhancement of expression of some anti-inflammatory M2 microglia markers, including IL-10, IL-1 receptor antagonist (IL-1Ra) and Cox-2. But it could significantly inhibit LPS-induced granulocyte colony-stimulating factor (G-CSF) expression. Tanshinone I could also inhibit LPS-induced NF-κB activation in microglia. Furthermore, it improved motor functions, normalized striatal neurotransmitters, and provided dopaminergic neuronal protection in MPTP-intoxicated mice. In vivo results also indicated that Tanshinone I could modulate MPTP-induced microglial activation, attenuated the increase of TNF-α, reserved the increase of IL-10 concentrain of MPTP-intoxicated mice. Tanshinone I does not alter MPTP toxic metabolite (MPP+) concentration. Oral administration of Tanshinone I at 10mg/kg daily for 2 weeks did not show liver toxicity. Tanshinone I selectively suppressed pro-inflammatory M1 genes expression in activated microglia, interestingly, partially reserved anti-inflammatory M2 genes expression. It also could provide neuroprotection in a mouse model of Parkinson׳s disease. These data indicated that Tanshinone I could make the most of the beneficial side and minimize the detrimental side of activated microglia simultaneously, and provide neuroprotection by modulating the immune response of microglia.

Wang S ，Jing H ，Yang H ，Liu Z ，Guo H ，Chai L ，Hu L ... -  《-》

Pseudoginsenoside-F11 (PF11) exerts anti-neuroinflammatory effects on LPS-activated microglial cells by inhibiting TLR4-mediated TAK1/IKK/NF-κB, MAPKs and Akt signaling pathways.

Pseudoginsenoside-F11 (PF11), an ocotillol-type ginsenoside, has been shown to possess significant neuroprotective activity. Since microglia-mediated inflammation is critical for induction of neurodegeneration, this study was designed to investigate the effect of PF11 on activated microglia. PF11 significantly suppressed the release of ROS and proinflammatory mediators induced by LPS in a microglial cell line N9 including NO, PGE2, IL-1β, IL-6 and TNF-α. Moreover, PF11 inhibited interaction and expression of TLR4 and MyD88 in LPS-activated N9 cells, resulting in an inhibition of the TAK1/IKK/NF-κB signaling pathway. PF11 also inhibited the phosphorylation of Akt and MAPKs induced by LPS in N9 cells. Importantly, PF11 significantly alleviated the death of SH-SY5Y neuroblastoma cells and primary cortical neurons induced by the conditioned-medium from activated microglia. At last, the effect of PF11 on neuroinflammation was confirmed in vivo: PF11 mitigated the microglial activation and proinflammatory factors expression obviously in both cortex and hippocampus in mice injected intrahippocampally with LPS. These findings indicate that PF11 exerts anti-neuroinflammatory effects on LPS-activated microglial cells by inhibiting TLR4-mediated TAK1/IKK/NF-κB, MAPKs and Akt signaling pathways, suggesting its therapeutic implication for neurodegenerative disease associated with neuroinflammation.

Wang X ，Wang C ，Wang J ，Zhao S ，Zhang K ，Wang J ，Zhang W ，Wu C ，Yang J ... -  《-》