Protective effects of hydro-alcoholic extract of Allium cepa on biochemical and morphometric parameters of mice kidneys exposed to formaldehyde

Formaldehyde is an air contaminant which has wide applications in industry and medicine and its destructive effects have been reported on the body systems.
The aim of this study was to investigate the influence of different doses of onion extract on biochemical parameters and histopathology of mice kidneys exposed to formaldehyde.
Material and 48 adult male mice were randomly divided into six groups. The control group did not receive any injection. The second group received formaldehyde 10 mg/kg for 14 days and the 3rd, 4th ,5th and 6th groups received 5,10,20 and 40 mg/kg/day of onion extract respectively in addition to intraperitoneal doses of formaldehyde. After 14 days, tissue preparation was done and using stereological technique, the sizes of the kidneys and glomeruli were measured. Also, serum urea and creatinine levels were measured. Data were analyzed by SPSS software.
We found significant decrease in the number of renal glomeruli in all of the groups that received onion and also decrease in the volume of glomeruli in the group which had received 10 mg onion/day, compared to those in the control group (P = 0.000). There were significant increase in the level of urea in the groups which had received doses of 10 and 20 mg of onion and in the creatinine levels of the groups which had received daily doses of 5, 20 and 40 mg of onion compared to those in the control group (P = 0.000). Formaldehyde caused renal damage and an increase in the levels of urea and creatinine as well as a decrease in the number and volume of the glomeruli of the kidneys.
Administration of daily doses of 40 mg hydro-alcoholic extract of onion for two weeks caused protective effect on kidney tissue exposed to the formaldehyde.