ABSTRACT
Objective@# To explore whether Lycium barbarum polysaccharide (LBP) can reduce the apoptosis of retinal photoreceptor cells in retinitis pigmentosa (RP) mice by inhibiting nuclear factor-kappa B (NF-κB)/NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) signaling pathway. @*Methods@# (i) In vitro experiments, mouse retinal ganglion cells (661W cells) were divided into normal, model, LBP low-dose (LBP-L, 40 mg/L), LBP middle-dose (LBP-M, 80 mg/L), LBP high-dose (LBP-H, 160 mg/L), and positive drug control (NLRP3 inhibitor, 160 mg/L) groups. And the 661W cells were exposed to varying concentrations of H2O2 ranging from 50 to 400 μmol/L to determine the optimal concentration for inducing apoptosis (200 μmol/L). Then the cell viability was assessed using Cell Counting Kit-8 (CCK-8), while the apoptosis rate was detected by flow cytometry; the expression of NLRP3 was detected by immunofluorescence; and the expression of apoptosis markers was detected by enzyme-linked immunosorbent assay (ELISA) and Western blot (WB). (ii) In vivo assays were carried out with the use of C57/BL6 and Rd10 mice. The animal experimental groups were divided into normal, model, LBP-L, LBP-M, LBP-H, and NLRP3 inhibitor groups, in which the normal group was C57/BL6 mice and the other groups were Rd10 mice. Ten mice were included in each group, and the corresponding drugs were administered intragastrically for a duration of four weeks. NF-κB/NLRP3 pathway and the expression of apoptosis markers were observed by electroretinogram, histopathological examination, and WB to assess the effects of LBP on retinal photoreceptor cell apoptosis.@*Results@#(i) In vitro experiments, compared with the normal group, the apoptosis rate of 661W cells in model group was significantly increased (P < 0.01), and the expression levels of key proteins of NF-κB/NLRP pathway, such as NLRP3, NF-κB, p-NF-κB, and pro-apoptotic protein caspase-3, were up-regulated (P < 0.01). The rate of Bax/Bcl-2 was increased (P < 0.01), and the concentrations of interleukin (IL)-1β and tumor necrosis factor (TNF)-α were significantly increased (P < 0.01). Compared with the model group, high dose of LBP decreased the apoptosis rate of 661W cells (P < 0.01), and down-regulated the expression levelsof the key proteins of NF-κB/NLRP3 pathway, including NF-κB, NLRP3, p-NF-κB, and caspase-3 (P < 0.01). The rate of Bax/Bcl-2 was decreased (P < 0.01), and the concentrations of IL-1β and TNF-α were decreased (P < 0.01). (ii) In vivo experiments, high dose of LBP significantly increased morphological changes in the outer nuclear layer (ONL) thickness of Rd10 mice, as well as functional changes in the amplitudes of the a-wave and b-wave (P < 0.01), which also down-regulated the expression levels of NF-κB (P < 0.05), NLRP3, p-NF-κB, and caspase-3 (P < 0.01), reduced the Bax/Bcl-2 rate (P < 0.01), and decreased the concentrations of IL-1β (P < 0.01) and TNF-α (P < 0.05). @*Conclusion@#LBP could improve both retinal morphology and function, providing protection to photoreceptors from apoptosis through the inhibition of the NF-κB/NLRP3 pathway.
ABSTRACT
Objective: To investigate the effect of Lycium barbarum polysaccharides on inflammatory cytokines in type 2 diabetes mellitus (T2DM) mice without myeloid differentiation factor 88 gene (MyD88-/-). Methods: Levels of interleukin 1β (IL-1β), IL-6, IL-8, transforming growth factor β1 (TGF-β1), and IL-10 in serum were assessed by ELISA in the MyD88-/- T2DM mice which had been administered with different doses of LBP (20, 40, and 80 mg/kg). Mouse macrophages Raw264.7 were stimulated by lipopolysaccharide (LPS) after treatment with different concentrations of LBP (25, 50, and 100 μg/mL). Then Western blotting was used to detect nuclear translocation level of nuclear factor κB (NF-κB) and protein expressions of inhibitor of NF-κB (IκB) and p-IκB. Results: Serum levels of IL-1β and TGF-β1 in MyD88-/- T2DM mice were down-regulated by LBP (P<0.05). Cell experiment proved that nuclear migration of NF-κB was dose-dependently inhibited by LBP, and the level of p-IκB was reduced by high dose of LBP. Conclusion: LBP can reduce some proinflammatory cytokines in the MyD88-/- T2DM mice, which may be related with its inhibitive effect on the phosphorylation of IκB and nuclear migration of NF-κB in the macrophages.
ABSTRACT
OBJECTIVE: To investigate the protective effects of Lycium barbarum polysaccharide(LBP) against injury from oxygen-glucose deprivation/reperfusion (OGD/RP) in primary cultured rat hippocampal neurons. METHODS: Cultured hippocampal neurons were exposed to oxygen-glucose deprivation (OGD) for 2 h followed by a 24 h reperfusion. The MTT assay and the lactate dehydrogenase (LDH)release were used to evaluate the protective effects of LBP. Superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA)were determined by spectrophotometry using commercial kits. Mitochondrial membrane potential (MMP) and the intracellular free calcium concentration ([Ca2+]i) in hippocampal neurons were measured using confocal laser scanning microscope (CLSM). RESULTS: Treatment with LBP (10-40 mg · L-1) significantly attenuated neuronal damage and inhibited LDH release in a dose-dependent manner. Furthermore, LBP enhanced activities of SOD and GSH-Px but it decreased their MDA content, inhibited [Ca2+]i elevation and decrease of MMP in ischemia-reperfusion treated hippocampal neurons. CONCLUSION: These findings suggested that LBP may be a potential neuroprotective agent for cerebral ischemia-reperfusion injury.
ABSTRACT
Objective:To study the effects of polysaccharide from Lycium barbarum (LBP) on cell apoptosis and bc1-2 gene expression in irradiated mice. Methods:Forty eight Kunming mice were divided into three groups (LBP group, radiation group and normal group). LBP chow was prepared through adding 0.8%LBP to normal chow and was supplied to LBP group. Normal chow was supplied to normal group and radiation group. LBP group and radiation group were exposed to whole-body 60Co ?-rays at the dose of 0.084 Gy/day for 6 w, five times a week and the total dose was 2.52Gy. Then the micronucleus frequency of polychromatic erythrocytes(MF),chromosome and sperm aberration frequency, caspase-3 mRNA expression, cell apoptosis and bcl-2 gene expression were detected. Results:LBP could significantly lower MF, chromosome and sperm aberration frequency, and cell apoptosis , and it could increase the proliferation activity of bone marrow cells and bc1-2 gene expression in irradiated mice and decrease caspase-3 mRNA expression.Conclusion:The radioprotective effect of LBP is related to regulation of cell apoptosis and bc1-2 gene expression.