Context Sumac [Rhus coriaria L. (RC) (Anacardiaceae)] is used as a folk medicine in the treatment of diabetes in Turkey.

Objective This study investigates the in vivo healing and protective effects of lyophilized extract sumac against streptozotocin (STZ)-induced diabetic complications.

Materials and methods Toxicity test was conducted in three different dosages (250, 500 and 1000 mg/kg of plant extracts, respectively). Six groups of seven rats each were used in experiments. Groups were designed as Normal control, Diabetic (DM), DM + AC-20 mg/kg, DM + Extract-100 mg/kg, DM + Extract 250 mg/kg and DM + Extract 500 mg/kg group. Experimental diabetes [50 mg/kg, intraperitoneal (i.p.)] was induced by STZ. The effects of oral administration of the extract for 21 d on the level of serum glucose, insulin, C-peptide, lipid profile (LP), hepatic and renal damage biomarkers (HRDB), diabetic serum biomarkers (DSB), glycosylated haemoglobin (HbA1c), antioxidant defence system constituents (ADSCs), malondialdehyde (MDA) and α-glucosidase activity in small intestine tissue were evaluated.

Results The extract decreased the levels of blood glucose in diabetic groups (an average of 31%). Triglyceride, total cholesterol, high-density lipoprotein and low-density lipoprotein levels were balanced by plant extract (500 mg/kg) supplementation in the diabetic group. Decreased levels of aspartate aminotransferase (89%), alanine aminotransferase (91%), lactate dehydrogenase (35%), alkaline phosphatase (47%), creatinine (25%) and urea (29%) were detected in plant extract (500 mg/kg) supplemented diabetic group. Additionally, a considerable increase in the HRDB, DSB, LP, MDA and fluctuated ADSC levels were restored in RC-extract supplemented groups.

Conclusion RC lyophilized extract has a healing effect on diabetes and diabetes-related complications.