Neuroprotective effects of an herbal medicine, Yi-Gan San on MPP+/MPTP-induced cytotoxicity in vitro and in vivo.

A traditional herb, Yi-Gan San, has been widely used for the management of neurodegenerative disorders in traditional East Asian Medicine. The present study investigated the neuroprotective effects of Yi-Gan San in 1-methyl-4-phenylpyridine/1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced cytotoxicity in vitro and in vivo and sought to clarify its underlying mechanisms. The effect of Yi-Gan San on 1-methyl-4-phenylpyridine was measured in terms of 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assays, caspase-3 activity, and western blot analysis of phosphorylated Akt, one of the survival-related signaling proteins in SH-SY5Y cells. The effects of Yi-Gan San were also confirmed in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced Parkinsonian mouse model using a rotarod test and tyrosine hydroxylase-immunohistochemistry. Pretreatment of Yi-Gan San with 1-methyl-4-phenylpyridine showed a significant protective effect on SH-SY5Y cells and significantly decreased the level of caspase-3 activity compared to the values for the 1-methyl-4-phenylpyridine-treated cells. This process increased the protein expressions of phosphorylated Akt, and an inhibitor of phosphatidylinositol 3-kinase (PI3K)/Akt, LY294002, significantly decreased this protective effect of Yi-Gan San. In the mouse Parkinson's disease model, treatment with Yi-Gan San also significantly improved motor functioning and prevented dopaminergic loss related to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine challenge. Using both in vitro and in vivo methods, this study revealed that Yi-Gan San has neuroprotective effects and rescues dopaminergic neurons from 1-methyl-4-phenylpyridine/1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine toxicity, possibly via the PI3K/Akt pathway.

Doo AR ，Kim SN ，Park JY ，Cho KH ，Hong J ，Eun-Kyung K ，Moon SK ，Jung WS ，Lee H ，Jung JH ，Park HJ ... -  《-》

Neuroprotective properties of icariin in MPTP-induced mouse model of Parkinson's disease: Involvement of PI3K/Akt and MEK/ERK signaling pathways.

Epimedium sagittatum is a traditional Chinese herb normally which is used to treat the osteoporosis, cardiovascular dysfunction, and to improve neurological and sexual function in China, Korea and Japan. Icariin is the major active ingredient in Epimedium sagittatum. In the present research, we examined the neuroprotective effects of icariin on dopaminergic neurons and the possible mechanisms in a mouse model of Parkinson's disease (PD). Ovariectomized PD mice were treated with vehicle or icariin (3 days before MPTP injections) with or without the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 or mitogen-activated protein kinase kinase (MEK) inhibitor PD98059. The dopamine (DA) content in the striatum was studied by HPLC. Western blot was used to determine the protein expressions of Bcl-2, Bax and Caspase 3 in the striatum. The numbers of tyrosine hydroxylase-immunoreactive (TH-IR) neurons in the substantial nigra pars compacta (SNpc) were assessed by immunohistochemistry. The activation of Akt and ERK by icariin were detected in doparminergic MES23.5 cells. Icariin pretreatment could ameliorate the decreased striatum DA content and the loss of TH-IR neurons in the SNpc induced by MPTP. The MPTP-induced changes of Bcl-2, Bax and caspase 3 protein expressions in the striatum could be reversed by icariin pretreatment. Blockade of PI3K/Akt or MEK/ERK signaling pathway by LY294002 or PD98059 could attenuate the increase of DA content in the striatum and TH-IR in the SNpc induced by icariin in PD mice model. Additionally, icariin treatment alone significantly induced the phosphorylation of Akt and ERK in a time dependent pattern in dopaminergic MES 23.5 cells. These effects were abolished by co-treatment with LY294002 or PD98059. These data demonstrated that icariin has neuroprotective effect on dopaminergic neurons in PD mice model and the potential mechanisms might be related to PI3K/Akt and MEK/ERK pathways.

Chen WF ，Wu L ，Du ZR ，Chen L ，Xu AL ，Chen XH ，Teng JJ ，Wong MS ... -  《-》

Dangguijakyak-san protects dopamine neurons against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced neurotoxicity under postmenopausal conditions.

Dangguijakyak-san protects dopamine neurons against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced neurotoxicity under postmenopausal conditions. Dangguijakyak-san (DJS), a famous traditional herbal formula, has long been used to treat gynecological disorders, including postmenopausal symptoms. This study evaluated the effects and mechanism of DJS on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurotoxicity in a postmenopausal mouse model induced by ovariectomy. Three weeks after ovariectomy, C57bl/6 female mice were divided randomly into (1) control, (2) MPTP (30 mg/kg/day, i.p., 5 days), (3) MPTP+estrogen (50 μg/kg/day, i.p., 5 days), and (4) MPTP+DJS (50 mg/kg/day, p.o., 5 days) groups. We investigated the behavioral recovery and dopamine neuron protection of DJS using the pole test and tyrosine hydroxylase (TH) immunohistochemistry. We also explored the mechanism by assessing the protein expression of Bax, Bcl-2, cytochrome c, and cleaved caspase-3. DJS treatment restored the movement behavior impaired by MPTP, showing a similar or better effect than estrogen. DJS protected TH-immunoreactive cells and fibers in the nigrostriatal region from MPTP toxicity. In addition, DJS inhibited the Bcl-2 decrease and Bax increase in mitochondria, cytochrome c release to the cytosol, and caspase-3 activation induced by MPTP. DJS showed behavior recovery and dopamine neuron protection against MPTP-induced toxicity via anti-apoptotic activities in ovariectomized female mice. These results suggest that DJS treatment is effective for postmenopausal neurodegenerative diseases.

Lee JM ，Hwang DS ，Kim HG ，Lee CH ，Oh MS ... -  《-》

Anti-apoptotic effect of modified Chunsimyeolda-tang, a traditional Korean herbal formula, on MPTP-induced neuronal cell death in a Parkinson's disease mouse model.

The modified-Chungsimyeolda-tang (DG) is an important traditional Korean herbal formula used in traditional oriental medicine for treatment of cerebrovascular disorders, including stroke. The formula is based on the book "Dongui Sasang Shinpyun". In the previous studies, the neuroprotective effect of DG is demonstrated in an in vitro Parkinson's disease (PD) model, and in this study, the 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) animal model of PD is used to evaluate the behavioral effect of DG and possible mechanism through anti-apoptosis of DG. 6-Hydroxydopamine (6-OHDA) also is used to evaluate the anti-apoptosis effect of DG in SH-SY5Y cells. MPTP was used to evaluate the behavioral damage and neurotoxicity in mice. The bradykinesia symptom was measured by a Pole test and a Rota-rod test in mice. Also the loss of tyrosine hydroxylase (TH)-positive neurons induced by MPTP was examined by an immunohistochemical assay. The DG-mediated anti-apoptosis effect was measured using an immunoblotting assay with apoptosis-related markers such as Bax and cleaved caspase-3. DG and 1-methyl-4-phenylpyridinium (MPP(+)) were co-treated with primary dopaminergic neurons to evaluate the protective effect of DG. The expression of caspase-3 and PARP was measured to detect the protective effect of DG from the damage by 6-OHDA. The treatment with DG resulted in prophylactic effects on MPTP-induced Parkinsonian bradykinesia and the immunohistochemical analysis showed that DG provided the neuroprotection against the MPP(+)-induced dopaminergic neurons loss through the anti-apoptosis effect. The present results suggested that it might be possible to use DG for the prevention of substantia nigra pars compacta (SNpc) degeneration induced by exposure to the toxic substances, such as MPTP/MPP(+), in PD mouse model.

Li H ，Park G ，Bae N ，Kim J ，Oh MS ，Yang HO ... -  《-》

Vitexin protects dopaminergic neurons in MPTP-induced Parkinson's disease through PI3K/Akt signaling pathway.

Hu M ，Li F ，Wang W 《Drug Design Development and Therapy》