The triterpene, maslinic acid (MA) lowers the blood glucose of adrenaline-induced diabetic mice and partial diabetic mice1. However, the anti-diabetic effects of MA in type 1 diabetes are unclear. Accordingly, we investigated the effects of MA on blood glucose levels streptozotocin (STZ)-induced diabetic rats, an experimental model for type 1 diabetes mellitus along with its influence on renal function and blood pressure; the major complications of diabetes. Oral glucose tolerance tests were conducted in separate groups of non-diabetic and STZ-treated diabetic rats given glucose load (0.86 g.kg-1, p. o.) after 18-h fast, followed by various MA doses (20, 40 and 80 mg kg-1, p.o.). Sub-chronic effects of MA on mean arterial blood pressure (MAP) and renal function were evaluated in conscious diabetic rats administered with MA twice every third day for five weeks. Sub-chronic effects of MA on blood glucose, mean arterial blood pressure (MAP) and renal function were evaluated in rats treated twice every third day for five weeks. Rats treated with deionized water (3 ml/kg, p.o.) and the standard hypoglycaemic drug metformin, 500 mg/ kg, p. o.) acted as untreated and treated positive controls, respectively.The effects of MA on proximal tubular Na+ handling were monitored in non-diabetic rats fed standard rodent chow supplemented with lithium chloride (12 mmol kg-1 dry weight) for 48 h prior to experimentation in order to raise plasma lithium to measurable concentrations without affecting renal Na+ or water excretion2. The animals were anaesthetized and the right jugular vein was cannulated to allow intravenous infusion of 0.077M NaCl. The urinary bladder was also cannulated via an incision in the lower abdomen. After a 3½ h equilibration period, urine samples were taken every 30 min over the 4h post-equilibration period of 1h control, 1h 30 min treatment and 1h 30 min recovery periods; blood samples were taken once per hour for the measurement of electrolyte and clearance marker concentrations. Li+ clearance is widely to assess proximal tubular function of the mammalian kidney3. Glomerular filtration rate (GFR) was assessed by creatinine clearance. Statistical comparison of the differences between the control means and experimental groups was performed with GraphPad InStat Software (version 4.00, GraphPad Software, San Diego, California, USA), using one-way analysis of variance (ANOVA), followed by Tukey-Kramer multiple comparison test. MA induced dose-independent hypoglycaemic responses in STZ-induced diabetic rats. Hepatic glycogen concentrations in STZ-induced diabetic rats were depleted at the end of the 5-week experimental period by comparison with non-diabetic rats. Sub-chronic MA treatment of STZ-induced diabetic rats with MA or metformin restored the hepatic glycogen concentrations to near normalcy. Acute MA infusion increased the fractional excretion of sodium (FENa) and lithium (FELi) in the absence of significant changes in GFR. STZ-induced rats exhibited marked weekly decreases in urinary Na+ excretion and elevated plasma creatinine concentration at the end of 5 weeks with concomitant reduction in GFR. MA treatment attenuated these changes and additionally reduced MAP indicating that maslinic acid might constitute a novel therapeutic strategy which can complement existing modern anti-diabetic medications.