Effects of Lycium barbarum polysaccharide on the photoinduced autophagy of retinal pigment epithelium cells

AIM: To investigate the relationship between autophagy and apoptosis in photoinduced injuries in retinal pigment epithelium (RPE) cells and how Lycium barbarum polysaccharide (LBP) contributes to the increased of RPE cells to photoinduced autophagy. METHODS: In vitro cultures of human RPE strains (ARPE-19) were prepared and randomly divided into the blank control, model, low-dose LBP, middle-dose LBP, high-dose LBP, and 3-methyladenine (3MA) groups. The viability of the RPE cells and apoptosis levels in each group were tested through cell counting kit-8 (CCK8) method with a flow cytometer (Annexin V/PI double staining technique). The expression levels of LC3II, LC3I, and P62 proteins were detected with the immunofluorescence method. The expression levels of beclin1, LC3, P62, PI3K, P-mTOR, mTOR, P-Akt, and Akt proteins were tested through Western blot. RESULTS: LBP considerably strengthens cell viability and inhibits the apoptosis of RPE cells after photoinduction. The PI3K/Akt/mTOR signal pathway is activated because of the upregulation of the phosphorylation levels of Akt and mTOR proteins, and thus autophagy is inhibited. CONCLUSION: LBP can inhibit the excessive autophagy in RPE cells by activating the PI3K/Akt/mTOR signaling pathways and thereby protect RPE cells from photoinduced injuries.

Effect of nano-selenium loaded with lycium barbarum polysaccharide on the proliferation of lens epithelial cells after UVB damage in vitro

AIM: To investigate the effect of nano-selenium loaded with different concentrations of lycium barbarum polysaccharide (LBP-SeNPs) on the proliferation of human lens epithelial cells (HLECs) from UV irradiation. METHODS: LBP-SeNPs were prepared and their particle size was detected. HLECs (SRA01/04) were irradiated with UVB for different time (0, 10, 20, 30, 40, 50, 60min) to construct a damaged model, the survival rate of cells was determined by methylthiazol tetrazolium (MTT) assay. The 4',6-Diamidine-2'-phenylindole dihydrochloride (DAPI) staining was used to observe the status of cell nucleus and drug entering cytoplasm through cell membrane in SRA01/04 cells after adding LBP-SENPS loaded with coumarin fluorescence agent 24h under fluorescence microscope. SRA01/04 normal and UVB-damaged cells were treated with different amounts of LBP-SeNPs at different concentrations, cells proliferation were observed. RESULTS: The particle size of LBP-SeNPs was stable in the range of 150-200 nm. The survival rate changes with time after UVB irradiation were statistically significant. The 10min of UVB exposure as the time was chosen to construct the cell damage model. With DAPI staining, LBP-SeNPs were observed to enter the cytoplasm through the cell membrane under fluorescence inverted microscope. Cytotoxicity of SRA01/04 at different concentrations of LBP-SeNPs were measured. Cell survival rate was statistically different compared with the control group. The higher the loading concentration of LBP in nano-Se drugs was, the higher the cell proliferation rate was (P<0.05). The lower the concentration of LBP-SeNPs, the higher the cell proliferation rate, showing a negative growth trend (P<0.05). The group with the highest average cell proliferation rate was 0.5 µmol/L 2.0 mg/mL LBP-SeNPs (128.80%). When the 2.0 mg/mL LBP-SeNPs group was selected for cell photography, the cell density was higher at 0.5 μmol/L. With the increase of concentration, SRA01/04 cells appeared more cytoplasm dehydration, cell shrinkage and apoptotic bodies, and cell density decreased. CONCLUSION: LBP-SeNPs has moderate particle size and good stability. LBP-SeNPs can protect HLECs (SRA01/04) from UVB-induced damage, and the cell proliferation rate is further increased with increasing the amount of loaded LBP and decreasing nano-selenium concentration.

Resveratrol and lycium barbarum polysaccharide improve Qinling giant panda (Ailuropoda melanoleuca Qinlingensis) sperm quality during cryopreservation

Background Semen cryopreservation has become an essential tool for conservation efforts of the giant panda (Ailuropoda melanoleuca); however, it is severely detrimental to sperm quality. Evidence has shown that antioxidants have the potential to reverse cryopreservation-induced damage in sperm. The purpose of this study was to screen effective antioxidants that could retain sperm quality during cryopreservation and to determine the optimal dose. Seven antioxidant groups, including resveratrol (RSV = 50 μM, RSV = 100 μM, RSV = 150 μM), lycium barbarum polysaccharide (LBP = 2 mg/mL, LBP = 4 mg/mL), laminaria japonica polysaccharides (LJP = 1 mg/mL) or combination (LBP = 2 mg/mL, LJP = 1 mg/mL and RSV = 100 μM) were assessed. Results RSV, LBP, LJP, or a combination of RSV, LBP, and LJP added to the freezing medium significantly improved sperm progressive motility, plasma membrane integrity, acrosome integrity, and mitochondrial activity during the cryopreservation process. Furthermore, the activities of glutathione peroxidase and superoxide dismutase were also improved. The levels of reactive oxygen species and malondialdehyde in semen were notably reduced. Hyaluronidase activity and acrosin activity were significantly increased in LBP-treated sperm. However, sperm total motility and DNA integrity were not significantly different between the groups. Conclusions RSV (50 μM) or LBP (2 mg/mL) are the best candidate antioxidants for inclusion in the freezing medium to improve the quality of giant panda spermatozoa during semen cryopreservation.

Lycium Barbarum Polysaccharide-Iron (III) Chelate as Peroxidase Mimics for Total Antioxidant Capacity Assay of Fruit and Vegetable Food

Quantitative evaluation of the antioxidant capacity of foods is of great significance for estimating food’s nutritional value and preventing oxidative changes in food. Herein, we demonstrated an easy and selective colorimetric method for the total antioxidant capacity (TAC) assay based on 3,3’,5,5’-tetramethyl-benzidine (TMB), hydrogen peroxide (H2O2) and synthetic Lycium barbarum polysaccharide-iron (III) chelate (LBPIC) with high peroxidase (POD)-like activity. The results of steady-state kinetics study showed that the Km values of LBPIC toward H2O2 and TMB were 5.54 mM and 0.16 mM, respectively. The detection parameters were optimized, and the linear interval and limit of detection (LOD) were determined to be 2–100 μM and 1.51 μM, respectively. Additionally, a subsequent study of the determination of TAC in six commercial fruit and vegetable beverages using the established method was successfully carried out. The results implied an expanded application of polysaccharide-iron (III) chelates with enzymatic activity in food antioxidant analysis and other biosensing fields.