Protective Effect Of Lycium Barbarum Polysaccharides Research Articles

Lycium barbarum polysaccharides ameliorate LPS-induced inflammation of RAW264.7 cells and modify the behavioral score of peritonitis mice.

In the present study, the anti-inflammatory effect of Lycium barbarum polysaccharide (LBP) and the possible molecular mechanism thereof were examined, so as to perceive the pharmacological action of LBP. With acute peritonitis in mice as the inflammatory model, the protective effect of LBP on peritonitis mice was evaluated by recording the effect of behavioral scores, studying the pathological damage of intestine and liver, and detecting the levels of inflammatory cytokines. Additionally, by establishing an lipopolysaccharide (LPS)-induced RAW264.7 macrophage model, the effect of LBP on RAW264.7 cell phenotype and culture supernatant inflammatory markers was observed. Finally, the activation of inflammation-related target genes, such as iNOS, Toll-like receptor 4 (TLR4), nuclear factor-κB (NF-κB) p65, and IκBα, were further detected. The results reveal that pretreatment with LBP could decrease the behavioral score of inflammatory mice, inhibit the secretion of pro-inflammatory factors, and reduce liver and intestine injury. LBP can regulate the effect of lipopolysaccharide on the polarization of RAW264.7 cells, and reduce the production of NO and cytokines (TNF-α, IL-1β, IL-6). Further, LBP pretreatment was found to be able to significantly reduce the expression of iNOS, TLR4, NF-κB p65, and IκBα in macrophages. The present research provides evidence that LBP exerts potential anti-inflammatory activity in LPS-induced RAW264.7 macrophages via inhibiting TLR4 and NF-κB inflammatory sites and improving the behavior score of peritonitis mice. PRACTICAL APPLICATIONS: In recent years, the number of deaths worldwide has continued to rise as a result of inflammation. Despite said rise in deaths, many synthetic drugs with anti-inflammatory properties are significantly expensive and also have a host of side effects. Thus, the development of new anti-inflammatory drugs derived from medicinal plants has broad application potential. As such, in the present study, lipopolysaccharide (LPS)-induced macrophages were used to establish inflammatory cell models to verify the anti-inflammatory effect of Lycium barbarum polysaccharides (LBP). Findings were made that LBP could reduce the expression levels of inflammatory cytokines and NO by regulating macrophage polarization and NF-κB translocation, and thus, could exert anti-inflammatory activity. In addition, by intraperitoneal injection of LPS to establish peritonitis mice models, LBP pretreatment was found to have significantly modified the behavioral score of mice, while decreasing the secretion of inflammatory factors and the damage to several organs. The present study provides a basis for further understanding the effects of LBP in acute inflammation.

RETRACTED: Lycium barbarum polysaccharides alleviate hydrogen peroxide-induced injury by up-regulation of miR-4295 in human trabecular meshwork cells

Glaucoma is a chronic neurodegenerative disease which produces damage to the optic nerve and causes sightlessness. Current remains lack of effective method for glaucoma. Lycium barbarum polysaccharides (LBPs) have pleiotropic effects on various diseases. However, the effect of LBPs on glaucoma remains unclear. The study aimed to clarify the protective effect of LBPs against hydrogen peroxide (H2O2)-induced oxidative damage in human trabecular meshwork (HTM) cells. HTM cells were exposed to H2O2 (0-400 μM) for 24 h to construct an oxidative damage model. Then, the different concentrations of LBPs (0-500 μg mL-1) were used to pre-treated HTM cells, and cell viability, apoptosis, protein levels of pro-/cleaved-caspase-3 and pro-/cleaved-caspase-9, and reactive oxygen species (ROS) generations were detected. MicroRNA (miR)-4295 inhibitor and its control were transfected into HTM cells, and the biological functions of miR-4295 were assessed in H2O2 and LBPs treated cells. Phosphatidylinositol 3-kinase (PI3K)/protein Kinase B (AKT) and extracellular regulated protein kinases (ERK) pathways were determined by western blot assay. LBPs significantly promoted cell viability, reduced apoptosis, declined cleaved-caspase-3/-9 and ROS level in HTM cells after H2O2 administration. MiR-4295 expression was up-regulated in H2O2 and LBPs treated cells. The protective effect of LBPs on H2O2-injured HTM cells was obviously reversed by miR-4295 inhibition. LBPs activated PI3K/AKT and ERK signaling pathways through up-regulation of miR-4295 in H2O2-injured HTM cells. These data demonstrated that LBPs alleviated H2O2-induced injury by up-regulation of miR-4295 in HTM cells, indicating the protective effect of LBPs on HTM cells against oxidative damage.

Antioxidant effects of Lycium barbarum polysaccharides on photoreceptor degeneration in the light-exposed mouse retina

We assessed the neuroprotective effects of Lycium barbarum Polysaccharides (LBP) on photoreceptor degeneration and the mechanisms involved in oxidative stress in light-exposed mouse retinas. Mice were given a gavage of LBP (150 mg/kg or 300 mg/kg) or phosphate buffered saline (PBS) for 7 days before exposure to light (5000 lx for 24 h). We found that LBP significantly improved the electroretinography (ERG) amplitudes of the a- and b-waves that had been attenuated by light exposure. In addition, changes caused by light exposure including photoreceptor cell loss, nuclear condensation, an increased number of mitochondria vacuoles, outer membrane disc swelling and cristae fractures were distinctly ameliorated by LBP. LBP treatment also significantly prevented the generation of reactive oxygen species (ROS) compared with PBS treatment. The levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and thioredoxin reductase (TrxR1) mRNA were decreased in PBS-treated mice compared with controls but increased remarkably in LBP-treated mice. The mRNA levels of the DNA repair gene Poly (ADP-ribose) polymerase (PARP14) was increased in PBS-treated mice but decreased significantly in the LBP-treated mice. Our findings indicate that pretreatment with LBP effectively protected photoreceptor cells against light-induced retinal damage probably through the up-regulation of the antioxidative genes Nrf2 and TrxR1, the elimination of oxygen free radicals, and the subsequent reduction in the mitochondrial reaction to oxidative stress and enhancement in antioxidant capacity. In addition, the decreased level of PARP14 mRNA in LBP-treated mice also indicated a protective effect of LBP on delaying photoreceptor in the light-damaged retina.

Lycium barbarum polysaccharide protects human keratinocytes against UVB-induced photo-damage

Ultraviolet B (UVB) irradiation plays a key role in skin damage, which induces oxidative and inflammatory damages, thereby causing photoaging or photocarcinogenesis. Lycium barbarum polysaccharide (LBP), the most biologically active fraction of wolfberry, possesses significant antioxidative and anti-inflammatory effects on multiple tissues. In the present study, the photoprotective effects and potential underlying molecular mechanisms of LBP against UVB-induced photo-damage were investigated in immortalized human keratinocytes (HaCaT cells). The data indicated that pretreatment with LBP significantly attenuated UVB-induced decrease in cell viability, increase in ROS production and DNA damage. LBP also significantly suppressed UVB-induced p38 MAPK activation, and subsequently reversed caspase-3 activation and MMP-9 expression. Notably, LBP was found to induce Nrf2 nuclear translocation and increase the expression of Nrf2-dependent ARE target genes. Furthermore, the protective effects of LBP were abolished by siRNA-mediated Nrf2 silencing. These results showed that the antioxidant LBP could partially protect against UVB irradiation-induced photo-damage through activation of Nrf2/ARE pathway, thereby scavenging ROS and reducing DNA damage, and subsequently suppressing UVB-induced p38 MAP pathway. Thus, LBP can be potentially used for skincare against oxidative damage from environmental insults.

Protective effects of LBP on cerebral ischemia reperfusion injury in mice and mechanism of inhibiting NF-κB, TNF-α, IL-6 and IL-1β

To observe the protective effects of Lycium barbarum polysaccharides (LBP) on cerebral ischemia reperfusion injury in mice and explore its mechanism. Common carotid artery thread was used to cause middle cerebral artery ischemia, and the thread was taken out after 2 h ischemia to achieve cerebral ischemia reperfusion injury in mice. Therefore, the transient middle cerebral artery occlusion (tMCAO) models were established to observe the effects of LBP (25,50, 100 mg•kg⁻¹) on neurological outcome, infarct size and water contents. HE staining was used to observe its effects on neurocytes of cerebral tissues in mice. Western blotting was used to evaluate the protein expression levels of NF-κB p65. ELISA was used to evaluate the levels of TNF-α, IL-6 and IL-1β in the serum. According to the results, LBP markedly improved neurologic deficits, and decreased infarct size and water contents at 24 h after reperfusion in mice. Pathological section of brain tissues also proved its protective effects on neurocytes. Western blot analysis indicated that LBP markedly down-regulated the protein level of NF-κB p65. ELISA indicated that LBP decreased the levels of TNF-α, IL-6 and IL-1β in the serum 24 h after reperfusion.In conclusion, LBP has protective effects on cerebral ischemia reperfusion injury in mice, and this effect may be associated with inhibiting NF-κB and inflammatory reactions.

Lycium barbarum polysaccharides protected human retinal pigment epithelial cells against oxidative stress-induced apoptosis.

To investigate the protective effect and its mechanism of lycium barbarum polysaccharides (LBP) against oxidative stress-induced apoptosis in human retinal pigment epithelial cells. ARPE-19 cells, a human retinal pigment epithelial cell lines, were exposed to different concentrations of H2O2 for 24h, then cell viability was measured by Cell Counting Kit-8 (CCK-8) assay to get the properly concentration of H2O2 which can induce half apoptosis of APRE-19. With different concentrations of LBP pretreatment, the ARPE-19 cells were then exposed to appropriate concentration of H2O2, cell apoptosis was detected by flow cytometric analysis. Expression levels of Bcl-2 and Bax were measured by real time quantitative polymerase chain reaction (RT-PCR) technique. LBP significantly reduced the H2O2-induced ARPE-19 cells' apoptosis. LBP inhibited the H2O2-induced down-regulation of Bcl-2 and up-regulation of Bax. LBP could protect ARPE-19 cells from H2O2-induced apoptosis. The Bcl-2 family had relationship with the protective effects of LBP.

Activation of the Nrf2/HO-1 Antioxidant Pathway Contributes to the Protective Effects of Lycium Barbarum Polysaccharides in the Rodent Retina after Ischemia-Reperfusion-Induced Damage

Lycium barbarum polysaccharides (LBP), extracts from the wolfberries, are protective to retina after ischemia-reperfusion (I/R). The antioxidant response element (ARE)–mediated antioxidant pathway plays an important role in maintaining the redox status of the retina. Heme oxygenase-1 (HO-1), combined with potent AREs in its promoter, is a highly effective therapeutic target for the protection against neurodegenerative diseases, including I/R-induced retinal damage. The aim of our present study was to investigate whether the protective effect of LBP after I/R damage was mediated via activation of the Nrf2/HO-1-antioxidant pathway in the retina. Retinal I/R was induced by an increase in intraocular pressure to 130 mm Hg for 60 minutes. Prior to the induction of ischemia, rats were orally treated with either vehicle (PBS) or LBP (1 mg/kg) once a day for 1 week. For specific experiments, zinc protoporphyrin (ZnPP, 20 mg/kg), an HO-1 inhibitor, was intraperitoneally administered at 24 h prior to ischemia. The protective effects of LBP were evaluated by quantifying ganglion cell and amacrine cell survival, and by measuring cell apoptosis in the retinal layers. In addition, HO-1 expression was examined using Western blotting and immunofluorescence analyses. Cytosolic and nuclear Nrf2 was measured using immunofluorescent staining. LBP treatment significantly increased Nrf2 nuclear accumulation and HO-1 expression in the retina after I/R injury. Increased apoptosis and a decrease in the number of viable cells were observed in the ganglion cell layer (GCL) and inner nuclear layer (INL) in the I/R retina, which were reversed by LBP treatment. The HO-1 inhibitor, ZnPP, diminished the LBP treatment-induced protective effects in the retina after I/R. Taken together, these results suggested that LBP partially exerted its beneficial neuroprotective effects via the activation of Nrf2 and an increase in HO-1 protein expression.

Lycium barbarum Polysaccharides Attenuate Cisplatin-Induced Hair Cell Loss in Rat Cochlear Organotypic Cultures

The aim of the present study was to investigate the effects of Lycium barbarum polysaccharides (LBP) on cisplatin-induced hair cell damage in the organ of Corti explant. The neonatal (P2–3) rat organ of Corti explant was exposed to cisplatin (20 μM; 48 h) with or without LBP pretreatment (150 and 600 μg/mL; 24 h). Hair cell loss was indicated by FITC-labeled phalloidin staining. The level of reactive oxygen species (ROS) and alteration of mitochondrial membrane potential (ΔΨm) in hair cells were analyzed using fluorescent probes 2′,7′-dichlorofluorescein diacetate and JC-1, respectively. The results showed that LBP significantly attenuated hair cell loss (p < 0.01). Hair cells pretreated with LBP showed significant reduction in ROS production and the decline of ΔΨm compared with cisplatin alone group (p < 0.01), indicating the protective effect of LBP on cisplatin-induced hair cell loss. Taken together, these results indicate that LBP was effective in attenuating cisplatin-induced hair cell loss by reducing the production of ROS and maintaining mitochondrial ΔΨm.

Lycium barbarum polysaccharides protect mice liver from carbon tetrachloride-induced oxidative stress and necroinflammation

Ethnopharmacological relevanceLycium barbarum has been used as a traditional Chinese medicine to nourish liver, kidneys and the eyes. Aim of the studyWe investigated the protective mechanisms of Wolfberry, Lycium barbarum polysaccharides (LBP) in carbon tetrachloride (CCl4)-induced acute liver injury. Materials and methodsMice were intraperitoneally injected with a 50μl/kg CCl4 to induce acute hepatotoxicity (8h) and were orally fed with LBP 2h before the CCl4 injection. There were six experimental groups of mice (n=7–8 per group), namely: control mice (vehicle only; 1mg/kg LBP or 10mg/kg LBP), CCl4-treated mice and CCl4+LBP treated mice (1mg/kg LBP or 10mg/kg LBP). ResultsPre-treatment with LBP effectively reduced the hepatic necrosis and the serum ALT level induced by CCl4 intoxication. LBP remarkably inhibited cytochrome P450 2E1 expression and restored the expression levels of antioxidant enzymes. It also decreased the level of nitric oxide metabolism and lipid peroxidation induced by CCl4. LBP attenuated hepatic inflammation via down-regulation of proinflammatory mediators and chemokines. Furthermore, LBP promoted liver regeneration after CCl4 treatment. The protective effects of LBP against hepatotoxicity were partly through the down-regulation of nuclear factor kappa-B activity. ConclusionLBP is effective in reducing necroinflammation and oxidative stress induced by a chemical toxin, thus it has a great potential use as a food supplement in the prevention of hepatic diseases.