Effects of Formaldehyde on Swiss Albino Mice

Formaldehyde (FA) is toxic over a range of doses. Even though at lower concentration, FA can react
with lipids, proteins, and nucleic acids which are cellular components. FA induces cellular toxic effects
in the liver, lungs, kidney and brain by damaging parenchyma and impairment of functions. This study
was carried out to evaluate the serum biochemical changes and cytotoxic effects on liver, lungs,
kidney and brain in Swiss albino mice caused by FA toxicity. For this purpose, mice were divided into
four equal groups i.e. Control, inhalation, oral and intraperitoneal. The exposure groups were further
divided into three subgroups which were subjected to exposure of FAdaily for 30 days in case of
inhalation and oral groups and 10 days in intraperitoneal group for acute toxic effects. After exposure,
blood and tissue samples were collected and analyzed for biochemical and morphological studies.
The serum biochemical parameters like Aspartate Transaminase (AST) and Alanine Transaminase
(ALT) were increased significantly (P‹0.05) in mice after FA exposure. The anatomical results
revealed gross morphological changes i.e. congestion and petechial hemorrhages on the liver. Study
showed gross abnormalities i.e. congestion on lungs. But no gross abnormal features observed on
kidney and brain. Histologically, the liver showed scattered lymphocytic infiltration, dilatation of
sinusoids, necrosis and degeneration of parenchymatous cells in orally exposed mice (10 mg/kg) and
diffuse lymphocytic infiltration, necrosis were seen in intraperitoneally FA injected mice at the rate of 7
and 10 mg/kg body weight. In 5 ppm treated inhaled group, lungs tissue revealed hemorrhages.
Kidney showed decreased Bowman’s space in 10 mg/kg treated oral group and congestion, tubular
necrosis, increased Bowman’s space in all intraperitoneally exposured groups.In the inhaled groups,
brain tissue showed degenerating neurons with either pyknotic or karyorrhectic nuclei are gradually
increased in highest concentration group. All these findings revealed that, FA has irritant toxic effects
on mice on a dose related manner.