Allium cepa Linn. (Liliaceae) (red onion) bulb aqueous extract increases membrane stability of red blood cells and ameliorates oxidative stress in diabetes

Abstract

The aim of this study was to assess the effects of Allium cepa aqueous extract on red blood cell membrane stability and oxidative stress in streptozotocin-induced diabetic Wistar rats. Various alterations of red blood cell (RBC) membrane appear both in diabetes mellitus and during the physiological aging processes. Diabetes mellitus decreases the life span of red blood cells therefore, it may change the membrane stability by acting through its effect on the aging process. Fresh A. cepa bulbs were mashed and macerated in distilled water for 48 h. The freeze dried filtrate (413.7 g) was used for the experiment. Male rats (120–170 g) were made diabetic by a single intraperitoneal injection of streptozotocin (60 mg/kg). Animals with fasting blood sugar (FBS) of 10 mmol/l on day 3 post challenge were selected, grouped, and treated with aqueous extract of A. cepa for 21 days at doses of 50, 150, 300 mg/kg and glibenclamide (2 mg/kg). A negative (challenged and untreated) and a normal control (unchallenged and untreated) groups were included. On day 21, blood samples were collected through the retrobulbar plexus of the medial cantus of the eye for osmotic fragility and in vivo oxidative stress markers analysis. The results showing showed an increase in percent stabilization (through increasing median corpuscular fragility, MCF) with increasing dose of the extract treatment. It also showed an increase in serum catalase (CAT), glutathione (GSH), and superoxide dismutase (SOD) which were significant (p < 0.05) at 150 and 300 mg/kg when compared with the negative control. Malondialdehyde (MDA) was also significantly reduced in these groups with increasing dose of the extract. This study suggests that increase in osmotic fragility of red blood cells attributed to the disturbance in ionic motion through their membrane could be stabilized with aqueous extract of A. cepa. Also, the extract ameliorates oxidation caused by reactive oxygen species and other free radicals produced in diabetic states.