Biochanin A Protects Against Lipopolysaccharide-Induced Damage of Dopaminergic Neurons Both In Vivo and In Vitro via Inhibition of Microglial Activation.

Neuroinflammation has been reported to be involved in the pathogenesis of Parkinson's disease (PD). Inhibition of microglia-mediated neuroinflammation might be a potential strategy for PD treatment. Biochanin A, is an O-methylated isoflavone, classified as a kind of phytoestrogens due to its chemical structure that is similar to mammalian estrogens. It has been found to possess antifibrotic, antiapoptotic, and antioxidant effects. In the present study, we investigated the neuroprotective effects of biochanin A on lipopolysaccharide (LPS)-induced dopaminergic neurons damage both in vivo and in vitro and the related molecular mechanisms. The results showed that biochanin A treatment for 21 days significantly attenuated the behavioral dysfunction of PD rats, prevented dopaminergic neurons damage, and inhibited activation of microglia in the LPS-induced PD rats. Furthermore, biochanin A decreased the levels of interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) in the serum, and inhibited the phosphorylation of ERK, JNK, p38 in the substantia nigra of PD rats. In vitro test, biochanin A also inhibited primary microglial activation and protected dopaminergic neurons, decreased the content of nitric oxide, IL-1ß, and TNF-α in supernatants, and inhibited the reactive oxygen species production. Taken together, these results suggest that biochanin A exerts protective effects on LPS-induced PD rats, and the mechanisms may be associated with the inhibition of inflammatory response and the MAPK signaling pathway.

Biochanin A protects dopaminergic neurons against lipopolysaccharide-induced damage and oxidative stress in a rat model of Parkinson's disease.

Parkinson's disease (PD) is the second most common neurodegenerative disease, which is characterized by loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc). Accumulated evidences have suggested that oxidative stress is closely associated with the dopaminergic neurodegeneration of PD that can be protected by antioxidants. Biochanin A that is an O-methylated isoflavone in chickpea is investigated to explore its protective mechanism on dopaminergic neurons of the unilateral lipopolysaccharide (LPS)-injected rat. The results showed that biochanin A significantly improved the animal model's behavioral symptoms, prevented the loss of dopaminergic neurons and inhibited the deleterious microglia activation in the LPS-induced rats. Moreover, biochanin A inhibited nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase) activation and malondialdehyde (MDA) production, increased superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities in the rat brain. These results suggested that biochanin A might be a natural candidate with protective properties on dopaminergic neurons against the PD.

Biochanin A attenuates LPS-induced pro-inflammatory responses and inhibits the activation of the MAPK pathway in BV2 microglial cells.

Inflammation in the brain, characterized by the activation of microglia, is believed to participate in the pathogenesis of Parkinson's disease. Biochanin A, an O-methylated isoflavone, is a natural organic compound and is classified as a phytoestrogen. In this study, using murine BV2 microglial cells, we investigated the anti-inflammatory effects of biochanin A and the possible mechanisms involved. BV2 microglial cells were treated with lipopolysaccharide (LPS) to induce pro-inflammatory responses and the cells were then treated with biochanin A. Cell viability was examined by MTT assay. The production of nitric oxide (NO) was examined using Griess reagent and intracellular reactive oxygen species (ROS production) was measured by DCFH-DA assay. The mRNA expression of interleukin-1ß (IL-1ß), inducible nitric oxide synthase (iNOS) and tumor necrosis factor-α (TNF-α) was examined by RT-PCR. The expression of p-ERK, p-JNK, p-p38 and iNOS was measured by western blot analysis. In addition, the protein and mRNA and phosphorylation levels of pro-inflammatory cytokines were determined by western blot analysis and RT-PCR, respectively. The results revealed that biochanin A attenuated LPS-induced microglial activation and the production of TNF­α, IL-1ß, nitric oxide and reactive oxygen species in a dose-dependent manner. Biochanin A significantly decreased the LPS-induced mRNA expression of TNF-α and IL-1ß, and inhibited iNOS mRNA and protein expression. Furthermore, biochanin A significantly inhibited the LPS-induced phosphorylation of c-Jun NH2-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) and p38. These findings suggest that the inhibitory effects of biochanin A on LPS-induced proinflammatory responses may be associated with the inhibition of mitogen-activated protein kinase (MAPK) signaling pathways in BV2 microglial cells.

Anti­fibrotic effects of Acremoniumterricola milleretal mycelium on immunological hepatic fibrosis in rats.

Acremoniumterricola milleretal mycelium (AMM) exerts numerous protective effects on organs, and has been used in Chinese herb prescriptions to treat refractory diseases. The aim of this study was to investigate the effects of AMM on immunological hepatic fibrosis induced by porcine serum (PS) in rats. Male Sprague Dawley rats were administered 0.5 ml sterile PS by intraperitoneal injections twice a week for 18 weeks. AMM (175, 350 or 700 mg/kg) and colchicine (0.1 mg/kg) were administered intragastrically each day until the rats were sacrificed. PS administration resulted in marked hepatic fibrosis, as assessed by increased oxidative stress and hepatic collagen content, as well as α­smooth muscle actin (α­SMA) expression. AMM significantly reduced liver damage and fibrosis. In addition, AMM decreased the elevation in hydroxyproline, hyaluronic acid, laminin and procollagen type III; increased the activity of superoxide dismutase and glutathione peroxidase; decreased α­SMA expression; and eliminated hepatic collagen deposits. Furthermore, AMM inhibited Smad2/3 phosphorylation and Smad7 expression. These results indicate that AMM is able to reduce oxidative stress, inhibit collagen synthesis and block the transforming growth factor­ß/Smad signaling pathway in a dose­dependent manner.

Astragalosides attenuate learning and memory impairment in rats following ischemia­reperfusion injury.

Astragalosides (ASTs) have been traditionally used in the treatment of various cardiovascular and cerebrovascular diseases. The aim of the present study was to investigate the neuroprotective effects of AST on learning and memory following focal cerebral ischemia/reperfusion in a rat model. A Morris water maze was used to measure the effect of AST on learning and memory impairments. A histological examination and Hoechst 33258 staining was used to observe the neuronal changes and apoptosis in the hippocampus. The activity of phospho-extracellular signal­regulated kinases (p­ERK), p­c-Jun N-terminal kinases (JNK) and p­Akt was measured by western blotting. The data revealed that AST improved the rats learning and memory abilities, attenuated neuronal cells apoptosis, increased the expression of p­ERK and p­Akt, and decreased the expression of p­JNK. These findings indicated that AST has protective effects that may be correlated with the inhibition of neuronal cell apoptosis and the regulation of p­ERK, p­Akt and p­JNK expression.

Protective effect of bilobalide on learning and memory impairment in rats with vascular dementia.

Vascular dementia (VD) is the second most common type of dementia in the elderly. Currently, there are no effective drugs for preventing or decreasing the progression of dementia. Bilobalide (BB) is a monomer extracted from Ginkgo biloba leaves. The present study investigated the neuroprotective effects of BB in a two-vessel occlusion (2-VO)-induced VD rat model. The results showed that BB (4 and 8 mg/kg) significantly protected VD rats against cognitive deficits in the Morris water maze. Biochemical assessment showed that BB (4 and 8 mg/kg) increased superoxide dismutase (SOD) activity and glutathione (GSH) content, and decreased nitric oxide synthase (NOS) activity and malondialdehyde (MDA) content. Additionally, BB (4 and 8 mg/kg) was found to alleviate neuronal apoptosis and to reduce the expression of tumor necrosis factor-α (TNF-α) in the brain cortex and the hippocampal CA1 region in VD rats. These results suggest that BB provides protection against learning and memory impairment by reducing free radical injury and inhibiting neuronal apoptosis in the brain cortex and hippocampal CA1 region in VD rats.

Protective effects of astragalosides on dexamethasone and Aß25-35 induced learning and memory impairments due to decrease amyloid precursor protein expression in 12-month male rats.

Alzheimer's disease (AD) is a chronic neurodegenerative disorder of the elderly characterized by learning and memory impairment. Stress level glucocorticoids (GCs) and ß-amyloid (Aß) peptide deposition are found to be correlated with dementia progression in patients with AD. The astragalosides (AST) was extracted from traditional Chinese herb Astragalus membranaceous. In this study, 12 months male rats were treated with Aß(25-35) (10 µg/rat, hippocampal CA1 injection) and dexamethasone (DEX, 1.5mg/kg, ig) and AST (8, 16 and 32 mg/kg, ig) or ginsenoside Rg1 (Rg1, 5 mg/kg, ig) for 14 days. We investigated the protective effect of AST against DEX+Aß(25-35) injury in rats and its mechanisms of action. Our results indicate that DEX+Aß(25-35) can induce learning and memory impairments and increase APP and Aß(1-40) expression. AST (16, 32 mg/kg) or Rg1 (5mg/kg) treatment significantly improve learning and memory, down-regulate the mRNA levels of APP and ß-secretase, decrease expression of APP and Aß(1-40) in hippocampus. The results indicated that DEX might increase hippocampal vulnerability to Aß(25-35) and highlight the potential neuronal protection of AST.

Dexamethasone and Aß25-35 accelerate learning and memory impairments due to elevate amyloid precursor protein expression and neuronal apoptosis in 12-month male rats.

Alzheimer's disease (AD) is an irreversible, progressive brain disorder of the elderly characterized by learning and memory impairment. Stress level glucocorticoids (GCs) and ß-amyloid (Aß) peptides deposition are found to be correlated with dementia progression in patients with AD. However, little is known about the simultaneous effects of glucocorticoids and Aß on learning and memory impairment and its mechanism. In this study, 12-month-old male rats were chronically treated with Aß(25-35) (10 µg/rat, hippocampal CA1 injection) and dexamethasone (DEX, 1.5mg/kg) for 14 days to investigate the effects of DEX and Aß(25-35) treatment on learning and memory impairments, pathological changes, neuronal ultrastructure, amyloid precursor protein (APP) processing and neuronal cell apoptosis. Our results showed that DEX or Aß(25-35) treatment alone for 14 days had caused slight damage on learning and memory impairments and hippocampal neurons, but damages were significantly increased with DEX+Aß(25-35) treatment. And the mRNA levels of the APP, ß-secretase and caspase 3 were significantly increased after DEX+Aß(25-35) treatment. The immunohistochemistry demonstrated that APP, Aß(1-40), caspase 3 and cytochrome c in hippocampus CA1 were significantly increased. Furthermore, Hoechst 33258 staining and Aß(1-40) ELISA results showed that DEX+Aß(25-35) treatment induced hippocampus CA1 neuron apoptosis and increased the level of Aß(1-40). The results suggest that the simultaneous effects of GCs and Aß may have important roles in the etiopathogenesis of AD, and demonstrate that stressful life events and GC therapy may increase the toxicity of Aß and have cumulative impacts on the course of AD development and progression.