Characterization of polysaccharides from the flowers of Nerium indicum and their neuroprotective effects

Yu, Man-Shan; Lai, Sau-Wan; Lin, Kim-Fung; Fang, Ji-nian; Yuen, Wai-Hung; Chang, Raymond Chuen‐Chung

doi:10.3892/ijmm.14.5.917

Cited by 17 publications

(20 citation statements)

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“…Preliminary studies suggested that cultured neurons pre-treated with Fructus lycii extract could attenuate Aß-induced apoptosis via the [25][26][27][28][29][30][31][32][33][34][35] peptide. Neurons were pretreated with LBP-III (10, 100 and 500 μg/ml) for 1 h, followed by a 4-h exposure to 25 μM of Aß [25][26][27][28][29][30][31][32][33][34][35] . Immunoblotting was performed to determine the level of phosphorylated PKR (Thr446/451), total PKR and ß-actin (used as the internal control).…”

Section: Discussionmentioning

confidence: 99%

“…After treatments, cellular proteins were extracted in ice-cold lysis buffer as described previously (6,19,20,(23)(24)(25)(26)(27)(28). Seventy micrograms of protein per lane were applied to SDS-PAGE (10%) and then were transferred onto a PVDF membrane (Bio-Rad).…”

Section: Preparation Of Lbp and Separation Of Lbp-iiimentioning

confidence: 99%

“…Primary neuronal cultures were prepared from day 17 embryonic Sprague-Drawley rats (Laboratory Animal Unit, The University of Hong Kong) according to our methods (6,19,20,(23)(24)(25)(26)(27)(28). Briefly, after removal of the meninges the cortices were minced and plated onto poly-L-lysine-(25 μg/ml) coated 6-well plates at 2x10 6 cells/well.…”

Section: Preparation Of Lbp and Separation Of Lbp-iiimentioning

confidence: 99%

“…Neurons were maintained in a 5% CO 2 incubator at 37˚C prior to treatments. Cultured neurons at day 7 in vitro were pre-treated with LBP at various concentrations for 1 h and followed by incubation with Aß [25][26][27][28][29][30][31][32][33][34][35] (25 μM, Sigma) for 24 h.…”

Section: Preparation Of Lbp and Separation Of Lbp-iiimentioning

confidence: 99%

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Characterization of the effects of anti-aging medicine Fructus lycii on β-amyloid peptide neurotoxicity

Lai²,

Ho³

et al. 2007

Int J Mol Med

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Abstract. Alzheimer's disease (AD) is an age-related neurodegenerative disease. There are increasing lines of evidence showing that the molecular signaling pathways in aged cells are altered so that cells are susceptible to injury. We and other laboratories have demonstrated the significant involvement of double-stranded RNA-dependent protein kinase (PKR) in ß-amyloid (Aß) peptide neurotoxicity and in AD. Fructus lycii (the fruit of Lycium barbarum) has long been used in oriental medicine as an anti-aging agent. Our previous studies demonstrated that the aqueous extract isolated from L. barbarum exhibited significant protection on cultured neurons against harmful chemical toxins such as Aß and dithiothreitol. We also showed that the polysaccharidecontaining extract (LBP) from L. barbarum exhibited neuroprotective effects in the retina against ocular hypertension in a laser-induced glaucoma animal model. In this study, we aimed to investigate whether LBP can elicit neuroprotection to neurons stressed by Aß peptides. Furthermore, we planned to isolate and identify the neuroprotective agent from LBP using chromatographic methods. Our results showed that pretreatment of LBP effectively protected neurons against Aß-induced apoptosis by reducing the activity of both caspase-3 and -2, but not caspase-8 and -9. A new arabinogalactan-protein (LBP-III) was isolated from LBP and attenuated Aß peptide-activated caspase-3-like activity.LBP-III markedly reduced the phosphorylation of PKR triggered by Aß peptide. Since the phosphorylation state of PKR increased with age, reduction of its phosphorylation triggered by Aß peptide may implicate that LBP-III from Fructus lycii is a potential neuroprotective agent in AD. As herbal medicine has received increasing attention for the treatment of AD, our study will open a window for the development of a neuroprotective agent for anti-aging from Chinese medicine.

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Section: Discussionmentioning

confidence: 99%

Section: Preparation Of Lbp and Separation Of Lbp-iiimentioning

confidence: 99%

Section: Preparation Of Lbp and Separation Of Lbp-iiimentioning

confidence: 99%

Section: Preparation Of Lbp and Separation Of Lbp-iiimentioning

confidence: 99%

See 2 more Smart Citations

Characterization of the effects of anti-aging medicine Fructus lycii on β-amyloid peptide neurotoxicity

Lai²,

Ho³

et al. 2007

Int J Mol Med

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“…3,4 Cultured neurons incubated with Aβ peptides also undergo apoptosis. [5][6][7][8] Aβ peptide-triggered neuronal cell death may involve different pathways including stress kinases activation, [8][9][10] membrane receptor-mediated response, 11,12 calcium imbalance and oxidative stress 2 resulting in activation of caspases. 13 However, the exact mechanisms of Aβ-mediated neurotoxicity are still unclear.…”

Section: Introductionmentioning

confidence: 99%

Beta-amyloid peptides induces neuronal apoptosis via a mechanism independent of unfolded protein responses

Suen

Kwok

et al. 2006

Apoptosis

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Accumulation of beta-amyloid (Abeta) peptides in senile plaques is one of the pathological hallmarks in Alzheimer's disease (AD), which can trigger apoptosis. We have previously demonstrated that Abeta triggered calcium release from the ER. Depletion of ER Ca(2+) ions has been reported leading to unfolded protein responses (UPR). While hypothesis has been made about UPR and neurodegeneration in AD, little is known about the effects of extracellular accumulation of Abeta on UPR. We have shown previously that activation of PKR in Abeta-triggered apoptosis. Since UPR can trigger PKR, our study aims to elucidate whether extracellular accumulation of Abeta peptides induce UPR in cultured neurons. Our results showed that Abeta could not trigger UPR signalings including phosphorylation of PERK, alternative cleavage of xbp-1 mRNA and induction of transcription of xbp-1 and Gadd153. Taken together, our results suggest that extracellular accumulation of Abeta peptides induce apoptosis via a mechanism independent of UPR.

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Polysaccharides from Wolfberry Antagonizes Glutamate Excitotoxicity in Rat Cortical Neurons

Yik

et al. 2009

Cell Mol Neurobiol

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Glutamate excitotoxicity is involved in many neurodegenerative diseases including Alzheimer's disease (AD). Attenuation of glutamate toxicity is one of the therapeutic strategies for AD. Wolfberry (Lycium barbarum) is a common ingredient in oriental cuisines. A number of studies suggest that wolfberry has anti-aging properties. In recent years, there is a trend of using dried Wolfberry as food supplement and health product in UK and North America. Previously, we have demonstrated that a fraction of polysaccharide from Wolfberry (LBA) provided remarkable neuroprotective effects against beta-amyloid peptide-induced cytotoxicity in primary cultures of rat cortical neurons. To investigate whether LBA can protect neurons from other pathological factors such as glutamate found in Alzheimer brain, we examined whether it can prevent neurotoxicity elicited by glutamate in primary cultured neurons. The glutamate-induced cell death as detected by lactate dehydrogenase assay and caspase-3-like activity assay was significantly reduced by LBA at concentrations ranging from 10 to 500 microg/ml. Protective effects of LBA were comparable to memantine, a non-competitive NMDA receptor antagonist. LBA provided neuroprotection even 1 h after exposure to glutamate. In addition to glutamate, LBA attenuated N-methyl-D-aspartate (NMDA)-induced neuronal damage. To further explore whether LBA might function as antioxidant, we used hydrogen peroxide (H(2)O(2)) as oxidative stress inducer in this study. LBA could not attenuate the toxicity of H(2)O(2). Furthermore, LBA did not attenuate glutamate-induced oxidation by using NBT assay. Western blot analysis indicated that glutamate-induced phosphorylation of c-jun N-terminal kinase (JNK) was reduced by treatment with LBA. Taken together, LBA exerted significant neuroprotective effects on cultured cortical neurons exposed to glutamate.

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Characterization of polysaccharides from the flowers of Nerium indicum and their neuroprotective effects

Cited by 17 publications

References 0 publications

Characterization of the effects of anti-aging medicine Fructus lycii on β-amyloid peptide neurotoxicity

Characterization of the effects of anti-aging medicine Fructus lycii on β-amyloid peptide neurotoxicity

Beta-amyloid peptides induces neuronal apoptosis via a mechanism independent of unfolded protein responses

Polysaccharides from Wolfberry Antagonizes Glutamate Excitotoxicity in Rat Cortical Neurons

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