Histological Effect of Formaldehyde as Food Preservative on Cerebellar Cortex of Albino Rat

Abstract
Background: Formaldehyde is an important chemical compound that is used widely in the industrial and medical setting. It is illegally used in excess amounts to preserve various kinds of foods that can affect the central nervous system particularly the cerebellar cortex.
Aim of Study: This work aims to evaluate the extent of histological changes of the cerebellar cortex of albino rat's offspring that may be induced by oral administration of formaldehyde to their mothers throughout pregnancy and lactation or direct administration to the offspring itself.
Material and Methods: The maximum dietary dose of formaldehyde (41.9mg/person/day) was used in this work. The used doses according to rat age were 0.74mg/adult, 0.104mg/2 weeks and 0.240mg/4 weeks. In this work, 42 pregnant albino rats and 120 of their offspring were used. They divided into 2 main groups; control and treated groups. The control group (Group C) consisted of 12 pregnant rats and 60 of their offspring. They were divided equally into C1, C2 and C3. The treated group (Group T) consisted of 30 pregnant rats and 60 of their offspring. They were divided equally into T1, T2 and T3. The pregnant rats of C1 and T1 received distilled water and formaldehyde respectively through-out pregnancy and for 2 weeks after delivery, then the 2 weeks old offspring received distilled water and formaldehyde respectively till the end of 8 weeks. The delivered rats of C2 and T2 received distilled water and formaldehyde respectively for 2 weeks. Then the 2 weeks old offspring received distilled water and formaldehyde respectively till the end of 8 weeks. The 2 weeks old offspring of C3 and T3 received distilled water and formaldehyde respectively till the end of 8 weeks. The cerebelli of all groups were extracted at two ages, at 4 and 8 weeks and immersed into suitable fixatives then prepared for light microscopic examination, in addition, the cerebelli of 8 weeks offspring were used for electron microscopic examination and morphometric studies.
Results: In the present work, oral administration of for-maldehyde induced delayed development of all layers of the cerebellar cortex in form of irregularity and change in the shape and size of cells, decreased the thickness of its layers. It also induced degenerative changes in the form of cytoplasmic vacuoles, pyknosis, ill-defined nuclei, fragmented cytoplasmic processes, dilated rough endoplasmic reticulum, dilated Golgi apparatus, mitochondria with destructed cristae, and presence of areas of ill-defined structures.
Conclusion: It could be concluded that the oral adminis-tration of formaldehyde caused delayed development and induced different histological changes in the cerebellar cortex of albino rat's offspring. These effects were directly propor-tional with the duration of its administration.