Effects of Astragalus Polysaccharides on Chymase, Angiotensin-converting Enzyme and Angiotensin II in Diabetic Cardiomyopathy in Hamsters

This study investigated the effects of Astragalus polysaccharides (APS), the main active extract from the traditional Chinese medicinal herb Astragalus membranaceus, on myocardial chymase, angiotensin-converting enzyme (ACE) and angiotensin II (Ang II) in diabetic cardiomyopathic hamsters. Plasma levels of insulin, C-peptide and glycosylated serum protein (GSP), plasma and myocardial levels of Ang II, and myocardial gene expression and activity of chymase and ACE were measured after treatment with APS at a dose of 1 g/kg per day or 1 ml of normal saline per day (controls) for 10 weeks. GSP levels, myocardial Ang II levels, and myocardial gene expression and activity of chymase were significantly decreased in diabetic hamsters after treatment with APS compared with controls. These results suggest that APS can inhibit the local chymase-Ang II system in diabetic cardiomyopathy.