Astragalus Polysaccharides Promote Wound Healing in Diabetic Rats by Upregulating PETN and Inhibiting the mTOR Pathway

The potential of astragalus polysaccharide for treating diabetes and its action mechanism

Type 2 diabetes presents a significant global health burden and is frequently linked to serious clinical complications, including diabetic cardiomyopathy, nephropathy, and retinopathy. Astragalus polysaccharide (APS), extracted from Astragalus membranaceus, exhibits various biochemical and physiological effects. In recent years, a growing number of researchers have investigated the role of APS in glucose control and the treatment of diabetes and its complications in various diabetes models, positioning APS as a promising candidate for diabetes therapy. This review surveys the literature on APS from several databases over the past 20 years, detailing its mechanisms of action in preventing and treating diabetes mellitus. The findings indicate that APS can address diabetes by enhancing insulin resistance, modulating the immune system, protecting islet cells, and improving the intestinal microbiota. APS demonstrates positive pharmacological value and clinical potential in managing diabetic complications, including diabetic retinopathy, nephropathy, cardiomyopathy, cognitive dysfunction, wound healing, and more. However, further research is necessary to explore APS's bioavailability, optimal dosage, and additional clinical evidence.

Astragalus polysaccharide improves diabetic ulcers by promoting M2-polarization of macrophages to reduce excessive inflammation via the β-catenin/ NF-κB axis at the late phase of wound-healing

Ethnopharmacological relevance

Astragalus polysaccharide (APS), the most biologically active ingredient of Astragali Radix, is used to treat diabetes mellitus (DM)-related chronic wounds in traditional Chinese medicine for several decades. This herb possesses an anti-inflammatory effect. Our study proved that APS can reduce excessive inflammation at the late phase of wound-healing in diabetic ulcers.

Aim of the study

To clarify the molecular mechanism of APS in promoting wound-healing via reducing excessive inflammation in diabetic ulcers during the late stages of wound-healing.

Methods and materials

The rat model of the diabetic ulcers was established via intraperitoneal injection of streptozocin (60 mg/kg). We detected the regulation of APS on diabetic ulcers by measuring wound-healing rates. Bioinformatics was used to predict the target genes of APS, and autodocking was used to predict the combination of APS and target genes. Immunohistochemistry, Enzyme-linked immunosorbent assay, Western blot, immunofluorescence staining, flow cytometry, and flow cytometric sorting were investigated.

Results

The results demonstrated that APS promoted wound-healing and inhibited excessive inflammation at the late phase of wound-healing in diabetic rats. Mechanistic findings showed that APS promoted the expression of β-catenin and Rspo3 while inhibiting the expression of NF-KB and GSK-3β, which leads to the transformation of M1-type macrophages into M2-type macrophages and thus reducing excessive inflammation at the late phase of wound-healing in diabetic ulcers.

Conclusion

We found an interesting finding that APS promoted the polarization of macrophages towards M2-type through the β-catenin/NF-κB axis to reduce excessive inflammation at the late phase of wound-healing. Therefore, APS may be a promising drug for treating diabetic ulcers in clinic.