Astragalus polysaccharides inhibit oxidation in high glucose-challenged or SOD2-silenced H9C2 cells

Extraction, structure, and activity of polysaccharide from Radix astragali

Radix astragali polysaccharide (RAP) is a water-soluble heteropolysaccharide. It is an immune promoter and regulator, and has antivirus, antitumor, anti-aging, anti-radiation, anti-stress, anti-oxidation and other activitys. The extraction, separation, purification, structure, activity and modification of RAP were summarized. Some extraction methods of RAP had been introduced, and the separation and purification methods of RAP were reviewed, and the structure and activity of RAP were highly discussed. Current derivatization of RAP was outlined. Through the above discussion that the yield of crude polysaccharides from Radix astragali by enzyme-assisted extraction was significantly higher than that by other extraction methods, but each extraction method had different extraction effects under certain conditions, and the activity efficiency of RAP was also different. Therefore, it is particularly important to optimize the extraction method with known better yield for the study of RAP. In addition, the purification and separation of RAP are the key factors affecting the yield and activity of RAP. At the same time, there are still few studies on the derivatiration of Radix astragali polysaccharide, but the researches in this area are very important. RAP also has many important pharmacological effects on human body, but its practical application needs further study. Finally, studies on the structure-activity relationship of RAP still need to be carried out by many scholars. This review would provide some help for further researches on various important applications of RAP.

Efficacy and safety of Shenqi Jiangtang Granules plus oral hypoglycemic agent in patients with type 2 diabetes mellitus: A protocol for systematic review and meta-analysis of 15 RCTs

OBJECTIVE

Shenqi Jiangtang Granules (SQJTG) has been widely used to treat patients with type 2 diabetes mellitus (T2DM). But whether there exists sufficient evidence on the efficacy of SQJTG in the treatment of T2DM is unclear. In order to assess the effects of SQJTG for T2DM, a systematic review and meta-analysis of randomized controlled trials (RCTs) were carried out.

METHODS

Eight databases, namely, PubMed, The Cochrane Library, EMBASE, Web of Science, Chinese National Knowledge Infrastructure, Chinese Scientific Journals Full-Text Database, CBM, and Wanfang database were searched up to May 2020. According to the Cochrane standards, the selection of study, the extraction of data, the assessment of study quality, and the analyses of data were carried out strictly. Then a fixed or random effects model was applied to analyze the outcomes.

RESULTS

Fifteen studies (N = 1392) in total conformed the inclusion criteria to this meta-analysis. Two subgroups were identified, based on different dose of SQJTG: oral hypoglycemic agent (OHA) vs OHA plus SQJTG (1 g); OHA vs. OHA plus SQJTG (1.5-3 g). The pooled results showed that, in comparison with OHA, OHA plus SQJTG significantly reduced fasting plasma glucose in both 1 g subgroup and 1.5-3 g subgroup; 2-hour post-meal blood glucose was also greatly reduced in the SQJTG 1 g subgroup and the SQJTG 1.5-3 g subgroup. Compared with OHA, SQJTG 1 g subgroup significantly reduced levels of glycated hemoglobin A1c, as well as the SQJTG 1.5-3 g subgroup. Homeostasis model-insulin resistance index was also reduced in both SQJTG 1 g subgroup and SQJTG 1.5-3 g subgroup; SQJTG group can also significantly reduce the total adverse events especially in reducing the incidence of hypoglycemia.

CONCLUSIONS

SQJTG is an effective and safe complementary treatment for T2DM patients. This meta-analysis provides an evidence for the treatment in patients with T2DM. While owing to the high heterogeneity and the trials' small sample size, it's crucial to perform large-scale and strict designed studies.

Protective Effects Of Astragalus Polysaccharides On Oxidative Stress In High Glucose-Induced Or SOD2-Silenced H9C2 Cells Based On PCR Array Analysis

BACKGROUND

Oxidative stress in cardiac myocytes is an important pathogenesis of diabetic cardiomyopathy (DCM). Previously, we reported that astragalus polysaccharide (APS) has protective effects against the oxidative stress of DCM. This study aimed to determine the effect of APS on the oxidative stress induced by hyperglycemia in H9C2 cells.

METHODS

Rat H9C2 cells were cultured in vitro and randomly divided into the control group, HG group, APS-HG group, siRNASOD2 group, and APS-siRNASOD2 group. The cellular ultrastructure was measured by transmission electron microscopy. Cell apoptosis was examined by TUNEL staining. Levels of reactive oxygen species (ROS) were detected by a quantitative fluorescence assay (DHE). 8-OH-dG and nitrotyrosine, the indicators of oxidative stress injury, were detected by immunohistochemistry. A PCR array was used to evaluate the expression levels of 84 oxidative stress genes in cultured cells, and the PCR array results were partially verified by Western blot.

RESULTS

APS treatment protected the H9C2 cell ultrastructure, reduced the level of cell apoptosis, inhibited cellular ROS production, and reduced the levels of oxidative stress injury indicators 8-OH-dG and nitrotyrosine in high glucose-induced or SOD2-silenced H9C2 cells. It also altered oxidative stress-related genes at the mRNA and protein levels.

CONCLUSION

APS may improve antioxidant capacity and inhibit oxidative stress injury in high glucose induced H9C2 cells.