scholarly journals Modulation of Calcium Oxalate Crystal Growth and Protection from Oxidatively Damaged Renal Epithelial Cells of Corn Silk Polysaccharides with Different Molecular Weights

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Jia-Yun Chen ◽  
Xin-Yuan Sun ◽  
Jian-Ming Ouyang

Corn silk polysaccharide (CSP0; molecular weight=124 kDa) was degraded by ultrasonication to obtain five degraded polysaccharides, namely, CSP1, CSP2, CSP3, CSP4, and CSP5, with molecular weights of 26.1, 12.2, 6.0, 3.5, and 2.0 kDa, respectively. The structures of these polysaccharides were characterized by FT-IR, 1H NMR, and 13C NMR analyses. The antioxidant activities, including scavenging ability for hydroxyl radicals and DPPH free radicals, chelation ability for Fe2+ ions, and reducing ability of CSP increased with decreased molecular weight of CSPs within 6.0 to 124 kDa. However, antioxidant activity weakened when the molecular weight of CSPs reached 3.5 and 2 kDa. CSP3 with a molecular weight of 6.0 kDa exhibited the strongest antioxidant activity. After protection with 60 μg/mL CSPs, the viability of human renal proximal tubular epithelial cells (HK-2) damaged by nano-COM crystals increased, the level of reactive oxygen species decreased, and the amount of COM crystal adhered onto the cell surface decreased. The ability of CSPs to protect cells from CaOx crystal damage was consistent with their antioxidant activity. CSPs can specifically combine with CaOx crystal to inhibit the conversion of calcium oxalate dihydrate crystal to calcium oxalate monohydrate crystal. All these results showed that the activity of CSPs was closely correlated with molecular weight. A very high or low molecular weight of CSPs was not conducive to their activity. CSPs, especially CSP3 with a molecular weight of 6.0 kDa, can be used as a potential antistone drug.

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Jian-Min Wang ◽  
Xin-Yuan Sun ◽  
Jian-Ming Ouyang

To study the antioxidant capacity of Astragalus polysaccharides (APS) with different molecular weights, we used hydrogen peroxide to degrade original Astragalus polysaccharide (APS0) with an initial molecular weight of 11.03 kDa and obtained three degraded polysaccharides with molecular weights of 8.38 (APS1), 4.72 (APS2), and 2.60 kDa (APS3). The structures of these polysaccharides were characterized by 1H NMR, 13C NMR, FT-IR, and GC/MS. The degradation process did not cause significant changes in the main chain structure of APS. The monosaccharide component of APS before and after degradation was slightly changed. The antioxidant ability in vitro (removing hydroxyl and ABTS radicals and reducing ability) and in cells (superoxide dismutase and malondialdehyde generation) of these polysaccharides is closely related to their molecular weight. If the molecular weight of APS is very high or low, it is not conducive to their activity. Only APS2 with moderate molecular weight showed the greatest antioxidant activity and ability to repair human kidney epithelial (HK-2) cells. Therefore, APS2 can be used as a potential antistone polysaccharide drug.


2015 ◽  
Vol 3 (9) ◽  
pp. 1864-1878 ◽  
Author(s):  
Xin-Yuan Sun ◽  
Jian-Ming Ouyang ◽  
Wen-Yu Zhu ◽  
Yu-Bao Li ◽  
Qiong-Zhi Gan

Size-dependent toxicity and interactions of calcium oxalate dihydrate crystals on Vero renal epithelial cells were demonstrated.


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Qian-Long Peng ◽  
Chuang-Ye Li ◽  
Yao-Wang Zhao ◽  
Xin-Yuan Sun ◽  
Hong Liu ◽  
...  

The protective effects of Porphyra yezoensis polysaccharides (PYPs) with molecular weights of 576.2 (PYP1), 105.4 (PYP2), 22.47 (PYP3), and 3.89 kDa (PYP4) on the oxidative damage of human kidney proximal tubular epithelial (HK-2) cells and the differences in adherence and endocytosis of HK-2 cells to calcium oxalate monohydrate crystals before and after protection were investigated. Results showed that PYPs can effectively reduce the oxidative damage of oxalic acid to HK-2 cells. Under the preprotection of PYPs, cell viability increased, cell morphology improved, reactive oxygen species levels decreased, mitochondrial membrane potential increased, S phase cell arrest was inhibited, the cell apoptosis rate decreased, phosphatidylserine exposure reduced, the number of crystals adhered to the cell surface reduced, but the ability of cells to endocytose crystals enhanced. The lower the molecular weight, the better the protective effect of PYP. The results in this article indicated that PYPs can reduce the risk of kidney stone formation by protecting renal epithelial cells from oxidative damage and reducing calcium oxalate crystal adhesion, and PYP4 with the lowest molecular weight may be a potential drug for preventing kidney stone formation.


2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Xin-Yuan Sun ◽  
Jian-Min Wang ◽  
Jian-Ming Ouyang ◽  
Li Kuang

This study aims at investigating the antioxidant activity and repair effect of green tea polysaccharide (TPS) with different molecular weights (Mw) on damaged human kidney proximal tubular epithelial cells (HK-2). Scavenging activities on hydroxyl radical (⋅OH) and ABTS radical and reducing power of four kinds of TPS with Mw of 10.88 (TPS0), 8.16 (TPS1), 4.82 (TPS2), and 2.31 kDa (TPS3) were detected. A damaged cell model was established using 2.6 mmol/L oxalate to injure HK-2 cells. Then, different concentrations of TPSs were used to repair the damaged cells. Index changes of subcellular organelles of HK-2 cells were detected before and after repair. The four kinds of TPSs possessed radical scavenging activity and reducing power, wherein TPS2 with moderate Mw presented the strongest antioxidant activity. After repair by TPSs, cell morphology of damaged HK-2 cells was gradually restored to normal conditions. Reactive oxygen species production decreased, and mitochondrial membrane potential (Δψm) of repaired cells increased. Cells of G1 phase arrest were inhibited, and cell proportion in the S phase increased. Lysosome integrity improved, and cell apoptotic rates significantly reduced in the repaired group. The four kinds of TPSs with varying Mw displayed antioxidant activity and repair effect on the mitochondria, lysosomes, and intracellular DNA. TPS2, with moderate Mw, showed the strongest antioxidant activity and repair effect; it may become a potential drug for prevention and treatment of kidney stones.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Seung Yun Lee ◽  
Sun Jin Hur

The purpose of this study was to determine the angiotensin converting enzyme (ACE) inhibitory and antioxidant activities of myofibrillar protein hydrolysates (HMPHs) of different molecular weights (<3 and <10 kDa) derived from Korean native cattle (Hanwoo breed) using a commercially available and inexpensive enzyme (Alkaline-AK). HMPH of both tested molecular weights had ACE inhibitory activity. Among the antioxidant activities, iron chelation and nitrite scavenging activities were higher in low-molecular-weight peptide of HMPH (<3 kDa), whereas 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was higher in high-molecular-weight peptide of HMPH (<10 kDa). HMPH did not induce cytotoxicity in RAW 264.7 cells at concentrations of 5–20 mg/mL. These results indicate that HMPH can be cheaply produced using Alkaline-AK and applied as a potential ACE inhibitor and antioxidant.


2018 ◽  
Author(s):  
Chanikan Sonklin ◽  
Natta Laohakunjit ◽  
Orapin Kerdchoechuen

Background Bioactive peptides can prevent damage associated with oxidative stress in the human body when consumed regularly. Recently year, peptides have attracted immense interest because of their beneficial functional properties, safety and little or no side effects when used at high concentration. Most antioxidant peptide has small size less than 1 kDa and contains high proportion of hydrophobic amino acid. Particularly Tyr, Leu, Ala, Ile, Val, Lys, Phe, Cys, Met and His exhibited high antioxidant activity. Mungbean protein contain high abundance of protein and hydrophobic amino acid contents, investigating its bioactivity is an important aspect of adding value to this by-product obtained from a growing industry. Therefore, the objectives of this study were to optimize the conditions used to generate MMPH with antioxidant activity form bromelain and to investigate the antioxidant activities of each molecular weight peptide fraction. Methods Response Surface Methodology (RSM) was used for screening the optimal conditions to produce Mungbean meal protein hydrolysate (MMPH). After that optimal MMPH was fractionated using ultrafiltration membranes with different molecular weight (MW) distribution. Crude-MMPH and four peptide fractions were investigated for five antioxidant activities: DPPH scavenging activity, Hydroxyl scavenging activity, Superoxide scavenging activity, Ferric reducing antioxidant power and metal ion chelation activity. Results The optimal condition of crude-MMPH production was 12 % (w/w) of bromelain and hydrolysis time for 12 h. The EC50 of DPPH was the highest for the F4 peptide fraction (MW<1 kDa) at 0.5320 mg/mL. Metal ion chelating activity was generally weak, except for the F4 that had a value of 43.94% at a protein concentration of 5 mg/mL. The F4 also exhibited high hydroxyl and superoxide radical scavenging activities (54 and 65.1%), but poor activity for ferric reducing antioxidant power (0.102 mM Fe2+/mg protein) compared to other peptide fractions and crude-MMPH. Molecular weight and amino acid were the main factors that determined the antioxidant activities of these peptide fractions. Results show that F4 have high antioxidant potentials. Discussion The lowest MW Fraction (less than 1 kDa) showed the highest DPPH activity, superoxide-, hydroxyl-scavenging activity and metal chelation activity. On the other hand, this fraction had poor ferric reducing power. This showed that low molecular weight has an important effect on antioxidant activities. According to the mechanism of the reaction, the potential of antioxidant activity was divided into two main groups: hydrogen atom transfer (HAT) and single electron transfer (SET). Therefore, this finding suggests that the antioxidant mechanism of peptides obtained mungbean could react with many species of free radicals by multiple mechanisms. Mungbean meal peptide can be developed into multiple functional foods which possess both antioxidant properties and aroma/taste.


2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Da Guo ◽  
Kai Yu ◽  
Xin-Yuan Sun ◽  
Jian-Ming Ouyang

Natural Gracilaria lemaneiformis sulfated polysaccharide (GLP0, molecular weight=622 kDa) was degraded by H2O2 to obtain seven degraded fragments, namely, GLP1, GLP2, GLP3, GLP4, GLP5, GLP6, and GLP7, with molecular weights of 106, 49.6, 10.5, 6.14, 5.06, 3.71, and 2.42 kDa, respectively. FT-IR and NMR results indicated that H2O2 degradation does not change the structure of GLP polysaccharides, whereas the content of the characteristic −OSO3H group (13.46% ± 0.10%) slightly increased than that of the natural polysaccharide (13.07%) after degradation. The repair effects of the polysaccharide fractions on oxalate-induced damaged human kidney proximal tubular epithelial cells (HK-2) were compared. When 60 μg/mL of each polysaccharide was used to repair the damaged HK-2 cells, cell viability increased and the cell morphology was restored, as determined by HE staining. The amount of lactate dehydrogenase released decreased from 16.64% in the injured group to 7.55%–13.87% in the repair groups. The SOD activity increased, and the amount of MDA released decreased. Moreover, the mitochondrial membrane potential evidently increased. All polysaccharide fractions inhibited S phase arrest through the decreased percentage of cells in the S phase and the increased percentage of cells in the G2/M phase. These results reveal that all GLP fractions exhibited repair effect on oxalate-induced damaged HK-2 cells. The repair ability is closely correlated with the molecular weight of the fractions. GLP2 with molecular weight of about 49.6 kDa exhibited the strongest repair effect, and GLP with higher or lower molecular weight than 49.6 kDa showed decreased repair ability. Our results can provide references for inhibiting the formation of kidney stones and developing original anti-stone polysaccharide drugs.


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