Unbiased stereological study of silymarin effects on adrenocortical structure of dexamethasone treated hamsters
Gholamreza Hamidian1, Naeem Alboghobeish1, Hossein Najafzadeh Varzi2 & Saleh Esmaeilzadeh3
Adrenal cortex is an essential portion for life and its function can be affected by many chemical agents and drugs. This study was to investigate effect of silymarin, a flavonoid, on adrenocortical structure of male dexamethasone treated hamsters.
In this study, 20 young adult male golden hamsters were randomly allocated to four groups: control group which received no drug; group two which received 7 mg/kg dexamethasone; group three which received 100 mg/kg silymarin; group four which received 7 mg/kg dexamethasone and 100 mg/kg silymarin. All animals were injected IP for seven consecutive days and conducted in accordance with humane care and ethical animal welfare. At the eighth day, the animals were euthanized and the adrenal glands were quickly removed, weighed and fixed in buffered formalin. The samples were processed by routine and standard paraffin embedding and serially sectioned in 5 μ thickness. The total volume of adrenal gland, adrenal cortex and cortical zone were estimated by Cavalieris point-counting principle using Weibels multipurpose test grid M42. Total number of adrenocortical cells in each zona was estimated by stereological methods. At least, statistical analysis was performed by ANOVA with LSD test to evaluate the means.
The results showed that the adrenal gland mass of dexamethasone treated hamsters was significantly decreased in comparison to animals that received dexamethasone with silymarin. It was also obtained that there are no significant difference in the zona glumerolosa volume and cell number among examined groups. The volume of the cortex, zona fasciculata, zona reticularis and cell number of these regions were significantly reduced in dexamethasone treated hamsters compared to controls (P<0.05), whereas in group four, this reduction was not observed. Finally it can be concluded that silymarin seem to be a suitable protective drug for side effect of glucocorticoid therapy in adrenal glands.