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Oxidative stress is associated with the development of many diseases, such as chronic inflammation, cardiovascular disease and cancer. Antioxidants can scavenge free radicals in the body, reduce the production of reactive oxygen species (ROS) and effectively prevent oxidative stress. Polysaccharide is a antioxidants that widely found in natural resources, which is a kind of high molecular polymer with antioxidant activity. It can prevent oxidative stress and play a role in disease prevention through various mechanisms. In this paper, the different types of polysaccharides were summarized, such as plant polysaccharides, algal polysaccharides, microbial polysaccharides and animal polysaccharides, and their antioxidant mechanism and application in the treatment of disease were also discussed. we hope this review can offer some theoretical basis and inspiration for the antioxidant activity study and application of polysaccharides from natural resources.

Abstract Temozolomide (TMZ) resistance is a major clinical challenge for glioblastoma (GBM). O6-methylguanine-DNA methyltransferase (MGMT) mediated DNA damage repair is a key mechanism for TMZ resistance. However, MGMT-null GBM patients remain resistant to TMZ, and the process for resistance evolution is largely unknown. Here, we developed an acquired TMZ resistant xenograft model using serial implantation of MGMT-hypermethylated U87 cells, allowing the extraction of stable, TMZ resistant (TMZ-R) tumors and primary cells. The derived tumors and cells exhibited stable multidrug resistance both in vitro and in vivo. Functional experiments, as well as single-cell RNA sequencing (scRNA-seq), indicated that TMZ treatment induced cellular heterogeneity including quiescent cancer stem cells (CSCs) in TMZ-R tumors. A subset of these were labeled by NES + /SOX2 + /CADM1 + and demonstrated significant advantages for drug resistance. Further study revealed that Epidermal Growth Factor Receptor (EGFR) deficiency and diminished downstream signaling may confer this triple positive CSCs subgroup’s quiescent phenotypes and chemoresistance. Continuous EGF treatment improved the chemosensitivity of TMZ-R cells both in vitro and in vivo, mechanically reversing cell cycle arrest and reduced drug uptake. Further, EGF treatment of TMZ-R tumors favorably normalized the response to TMZ in combination therapy. Here, we characterize a unique subgroup of CSCs in MGMT-null experimental glioblastoma, identifying EGF + TMZ therapy as a potential strategy to overcome cellular quiescence and TMZ resistance, likely endowed by deficient EGFR signaling.

Malignant tumors have become the main cause of harm to human life and health. Development for new antitumor drugs and the exploration to drug carriers are becoming the concerned focus. In this study, we exploited our experiments to explore the effect of NCTD-NLC on liver cancer cells: the HepG2 cells cultured in vitro were given with NCTD-NLC administration; then, the estimation on cellular proliferation and apoptosis was accomplished through MTT and flow cytometry. Six hours after the administration, we performed the High Performance Liquid Chromatography (HPLC) detection to estimate the NCTD content in the heart, liver, spleen, lung, kidney and plasma of rats. Then, our outcomes showed that NCTD-NLC had a notable inhibitory effect on HepG2 cells, leading to a gradually decreased cellular viability. Cell viability was negatively correlated with NCTD-NLC concentration. Along with the concentration increasing, significantly increasing cellular apoptosis and gradually decreasing cellular viability were observed. The apoptosis rate was positively correlated with the concentration of NCTD-NLC. On the basis of the data we obtained, we found that the group with NCTD-NLC tail vein injection had an obvious advantage in drug delivery when compared with other groups. Through the tumorigenesis test to nude mice, we found that the tumor inhibition rate of the NCTD-NLC tail vein injection group had a 27.48% elevation in contrast to the NCTD gavage group, and it was also the group with the best tumor inhibition efficiency. In conclusion, the NCTD-NLC prepared in this study had a mighty inhibitory effect towards HepG2 cellular viability and an accelerating work on apoptosis. Tail vein injection of NCTD-NLC has the best drug delivery effect.

Oxidative stress is associated with the development of many diseases, such as chronic inflammation, cardiovascular disease, and cancer. Antioxidants can scavenge free radicals in the body, reduce the production of reactive oxygen species (ROS), and effectively prevent oxidative stress. Polysaccharides--a kind of high molecular polymer with antioxidant activity--are antioxidants that are widely found in natural sources. They can prevent oxidative stress and play a role in disease prevention through various mechanisms. In this paper, the different types of polysaccharides were summarized, such as plant, algal, microbial and animal polysaccharides, and their antioxidant mechanism and application in the treatment of disease were also discussed. We hope this review can offer some theoretical basis and inspiration for the antioxidant activity study and application of polysaccharides from natural sources. [ABSTRACT FROM AUTHOR]

Objective To explore the relationship between spinal cord dysplasia and congenital complex anorectal malformations (ARMs) and how they affect the defecatory function in children. Methods We retrospectively analyzed the clinical data of 148 children undergoing staged surgeries for complex ARMs between October, 2012 and February, 2017. According to the findings by lumbosacral magnetic resonance imaging (MRI), the children were divided into normal spinal cord group and abnormal spinal cord development group to analyze the distribution of spinal cord dysplasia in different types of ARMs and the impact of anomalies in spinal cord development on the development of the perianal muscles, anorectal manometry, and the defecatory function. Results Of the 148 children, 34 (23.0%) showed anomalies in spinal cord development, including steatosis of the terminal filament in 21 (61.8%) cases, intraspinal lipoma in 7 (20.6%) cases, syringomyelia in 1 (2.9%) case, intraspinal cystic lesion in 3 (8.8%) cases, and mixed spinal cord anomaly in 2 (5.9%) cases. We classified AMRs into different types according to Krickenbeck international classification, and abnormal spinal cord development was found in 20.0% (1/5) of the patients with rectal stenosis, 25.0% (5/20) of the patients with rectal atresia, 20.0% (1/5) of the patients with perineal fistula, 22.2% (8/36) of the patients with rectobulbar fistula, 18.2% (6/33) of the patients with rectoprostatic fistula, 25.0% (1/4) of the patients with rectovesical fistula, 24.2% (8/33) of the patients with vestibular fistula, 66.7%(2/3) of the patients with rectovaginal fistula, and 22.2% (2/9) of the patients with cloaca; No significant difference was found in the incidences of abnormal spinal cord development among the 9 groups (P=0.874). A total of 145 patients were evaluated for perianal muscle development during the surgery, and 26 patients had excellent, 105 had good, and 14 had poor development; the development of perianal muscles differed significantly between the children with normal and those with abnormal spinal cord development (P=0.005). Forty-four patients received anorectal manometry, which Showing no significant difference in resting anal pressure between the children with normal and abnormal spinal cord development (35.0±14.8 vs 27.9±14.3 mmHg, P=0.268); the positivity rate of rectoanal inhibitory reflex (RAIR) was lower in normal spinal cord group than in spinal cord dysplasia group (45.9% vs 71.4%), but the difference was not statistically significant (P=0.412). Follow-up of the patients for defecatory function assessment using the modified Rintal scale showed no significant difference in the constituent ratios of defecatory function between the 2 groups (P=0.416). Conclusion Spinal cord dysplasia is associated with perianal muscle development in children with complex ARMs, for whom routine lumbosacral MRI should be performed to detect the presence of spinal cord dysplasia.

Objective To assess the application of high-resolution anorectal manometry (HRAM) for evaluating postoperative defecation function in children following surgical repair of congenital anorectal malformations (ARMs). Methods A total of 77 children undergoing surgeries for ARMs in our hospital. from 2014 to 2017 were enrolled in this study. The patients' postoperative defecation function was evaluated based on Kelly scores at 6 to 12 months after the surgeries. The results of HRAM for measuring the resting and maximum pressures, effective length of the anal canal, and rectoanal inhibitory reflex recovery were compared among the patients with different positions of ARM and with different postoperative defecation functions. Of the 77 children included, 32 were found to have low ARM (with a distance < 1.5 cm between the blind rectal pouch and the anal crypt) and 45 had high ARM (≥1.5 cm); 72 of the children had good postoperative defecation function (Kelly score of 3-6) and 5 had poor defecation function (Kelly score of 0-2). Results We compared the HRAM findings between the 32 children having low ARM and the 40 children with high ARM in the 72 children with good postoperative defecation function, and the results showed significantly higher mean resting pressure (38.00±12.33 vs 32.27±11.86 mmHg) and maximum resting pressure (42.65± 14.23 vs 36.67±12.10 mmHg), a longer effective length of the anal canal (2.43±0.30 vs 2.18±0.33 cm), and a higher recovery rate of rectoanal inhibitory reflex (90.63% vs 17.50%) in the former children (all P < 0.05). In the 45 children with high ARMs, the children with poor defecation function had a significantly mean higher resting pressure than those with good defecation function (32.27±11.86 vs 26.08±2.36 mmHg, P < 0.05) and had also a higher maximum resting pressure (36.67±12.10 vs 29.96±2.55 mmHg, P < 0.05). Three-dimensional image analysis highlighted the presence of a low pressure band or a pressure loss zone in the images in the children with poor postoperative defecation function. Conclusion Children with low ARMs have significantly higher mean resting pressure and maximum resting pressure, a longer effective anal canal length, and a higher rectoanal inhibitory reflex recovery rate than those with high ARMs. The anal sphincter function can be evaluated based on the three-dimensional images, and HRAM can be used for assessing postoperative defecation function in children with ARMs.