Hypoglycaemic effect of comatin, an antidiabetic substance separated from Coprinus comatus broth, on alloxan-induced-diabetic rats

Comatin, an inhibitor of the non-enzymatic glycosylation (NEG) reaction, was isolated from Coprinus comatus fermentation broth by macroporous resin separation, followed by chromatographic purification using a C18 reversed-phase column. The compound was identified as 4,5-dihydroxy-2-methoxy-benzaldehyde by high-resolution MS, IR, NMR and UV analyses. The hypoglycaemic effect of comatin, on both normal and alloxan-induced-diabetic rats, was investigated in the paper. The blood glucose concentration of normal rats treated by the comatin at 80 mg/kg body weight was reduced from 5.14 mM to 4.28 mM in 3 h. Also, the concentrations of fructosamine, triglycerides and total cholesterol in induced-diabetic rats were significantly decreased. These results indicated that comatin could maintain a low level of blood glucose and improve glucose tolerance.