Ethanol extract of the mushroom Coprinus comatus exhibits antidiabetic and antioxidant activities in streptozotocin-induced diabetic rats

CONTEXT: Edible mushrooms have a long history of use in traditional Chinese or Japanese medicine. Coprinus comatus (O.F. Müll.) Pers. (Agaricaceae) contains antioxidant and antidiabetic agents. OBJECTIVE: To identify the benefits of ethanol extracts of the C. comatus fruit body in streptozotocin-induced hyperglycaemic rats by evaluating their blood glucose, glycosylated haemoglobin (HbA1c), insulin, glucagon-like peptide-1 (GLP-1), dipeptidyl peptidase-4 (DPP-4), and glutathione (GSH) levels, with and without extract administration. MATERIALS AND METHODS: Wistar rats were either left untreated or were administered 45 mg/kg body weight (BW) streptozotocin; 45 mg/kg BW metformin; or 250, 500, or 750 mg/kg BW extract for 14 days. The blood glucose, GLP-1, DPP-4, GSH, insulin, and HbA1c levels were determined. Data were analysed using analysis of variance and Duncan’s multiple range tests. RESULTS: Preliminary data showed that administration of C. comatus ethanol extract dose of 250, 500, and 750 mg orally has no toxicity effects after 24 h administration. The ethanolic extract of fruiting body of C. comatus considerably reduced the rat’s fasting blood glucose levels 26.69%, and DPP-4 6.97% at dose of 750 mg. The extract reduced HbA1c 4–4.30%, increased GLP-1 71.09%, GSH 11.19% at dose of 500 mg, and increased insulin levels 13.83%. Extracts contain bioactive compounds such as flavonoid, alkaloid, terpenoids, vitamins C and E, rutin, and saponin. CONCLUSIONS: The C. comatus extract can be used as herbal medicine that reduces diabetic symptoms. Further investigation on C. comatus extracts should be conducted with gas chromatography-mass spectrometry to characterise the bioactive compounds.