Journal of Ethnopharmacology 69 (2000) 247 – 252 Short communication Effects of Opuntia megacantha on blood glucose and kidney function in streptozotocin diabetic rats P. Bwititi a , C.T. Musabayane b, *, C.F.B. Nhachi c a Department of Medical Laboratory Sciences, Faculty of Medicine, Uniersity of Zimbabwe, Harare, Zimbabwe b Department of Physiology, Faculty of Medicine, Uniersity of Zimbabwe, PO Box MP 167, Mount Pleasant, Harare, Zimbabwe c Department of Clinical Pharmacology, Faculty of Medicine, Uniersity of Zimbabwe, Harare, Zimbabwe Received 3 January 1999; received in revised form 30 June 1999; accepted 6 July 1999 Abstract The purpose of the study was to investigate the effects of Opuntia megacantha leaf extracts on blood glucose concentrations and kidney function in normal and streptozotocin (STZ) – diabetic rats. STZ-diabetic and non-diabetic rats were orally administered extracts of O. megacantha leaves (20 mg/100 g body weight) daily for 5 weeks and respective control rats were administered normal saline (0.1 ml/100 mg body weight). Urine volume, urinary outputs of Na + ,K + and creatinine were monitored daily over the 5-week period. Plasma concentrations of Na + ,K + , urea and creatinine and the glomerular filtration rate (GFR) as assessed by creatinine clearance were determined after 5 weeks. Plasma glucose concentrations in STZ-diabetic and non-diabetic rats were reduced by the administration of leaf extracts of O. megacantha. However, leaf extracts increased urinary Na + output in STZ-diabetic and non-diabetic rats, concomitantly with a reduction in plasma concentration of the ion. O. megacantha leaf extracts significantly increased plasma creatinine and urea concentrations in non-diabetic and STZ-diabetic rats. Administration of the leaf extract was also associated with an increased GFR in STZ-diabetic rats (from 1.8 0.3 ml/min to 2.8 0.3 ml/min, n =8) although the rate was unaltered in non-diabetic rats. The results suggest that leaf extracts of O. megacantha not only reduce blood glucose levels, but may be toxic to the kidney as shown by the elevation in plasma urea and creatinine concentrations and the reduction of plasma Na + concentration. © 2000 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Diabetes mellitus; Streptozotocin; Renal function; Opuntia megacantha www.elsevier.com/locate/jethpharm 1. Introduction Extracts from Aloe barbadensis, Solanum er - bascifolum and Opuntia streptacantha are used in * Corresponding author. Tel.: +263-4-333678; fax: +263- 4-333678 or 333407. E-mail address: ctm@kidney.uz.zw (C.T. Musabayane) 0378-8741/00/$ - see front matter © 2000 Elsevier Science Ireland Ltd. All rights reserved. PII:S0378-8741(99)00123-3