comparative study of the effect of Budesonide versus prednisolone on adrenal gland of the male rabbit

ABSTRACT

Although oral glucocorticoids are the treatment of choice for moderate to severe pancolitis, their systemic side effects and adrenal suppression account for considerable morbidity. Budesonide is a new intestinal topical active glucocorticoid which displays high therapeutic efficacy and high systemic tolerability. To deliver the active drug to ileal and ileocecal area, Budesonide has been formulated into enterocapsule preparation. Several studies compared the efficacy of Budesonide with that of Prednisolone. However, few determined the extent of adrenocortical suppression occurring with both drugs on histological basis. In this work, fifteen adult male New Zealand albino rabbits were used. They were classified into three equal groups. Group I served as control. Group II included animals that received intragastrically one tablet of 5 mg prednisolone daily for four weeks. Group III included animals that received orally one capsule of entocort containing 3 mg budesonide every other day for four weeks. The adrenals were processed for histological and immunohistochemical study. In the present comparative study, evidence of adrenal suppression was significantly greater in the prednisolone group than in budesonide treated animals. Light microscopic examination of H and E stained sections of prednisolone group, revealed an apparent decrease in the size of zona fasciulata cells which was proved significant by morphometric study. Moreover, Oil red stained sections of group II demonstrated a relative decrease in cytoplasmic lipid content of both zona glomerulosa and fasciculata. Using chromaffin reaction, it was noticed that there was a relative increase in the number of nor-epinephrine cells than in group III. Immunohistochemical study showed that most of the nuclei of cells in zona fasciculata in group II were negatively stained for proliferating cell nuclear antigen [PCNA] which was further proved significant morphometrically using the PCNA index. Thus it was concluded that, the budesonide preparation is associated with much less impairment of adrenal axis function. Therefore, budesonide offers a useful advance in treatment of inflammatory bowel disease