Effect of Ginkgo Biloba Leaves Extract on Some Formaldehyde Induced Toxicity in hippocampus of Adult Male Albino Rats

 Formaldehyde (FA) heavily impacts the everyday consumer products. It is widely used in the
construction, textile, furniture, medical, chemical, and pharmaceutical industries. Exposure to FA poses
a significant threat to public health. It can cause severe central nervous system impairment. Extract from
the leaves of Ginkgo biloba exerts a novel spectrum of biological, pharmacological and therapeutic
properties against oxidative stress, so it was of special concern to investigate the role of Ginkgo biloba
leaves extract (GBE) on the neurotoxic effects of FA on hippocampus of adult male albino rats. Thirty
adult male albino rats were used in the present study. They were divided into 5 equal groups: Group I
negative control, Group II received distilled water by intraperitoneal (i.p.) injection. Group III received
GBE (300 mg/kg/day) orally. Group IV received FA (0.2 mg/kg/day i.p. and Group V received 0.2
mg/kg FA + 300 mg/kg GBE. After the end of the study ( 4weeks), all rats were sacrificed and brain
were dissected out and hippocampus subjected to estimation of superoxide dismutase (SOD),
glutathione peroxidase (GSH-Px) catalase (CAT) and malondialdehyde (MDA) levels. Histological
examination of the hippocampus and immunohistochemical staining for Glial fibrillary acidic protein
(GFAP) were also done. The results of this study revealed that, the levels of SOD, CAT and GSH-Px
were significantly decreased, while MDA level in hippocampus tissue were significantly increased in
rats treated with FA compared to those of the controls. Microscopic examination of neurons of the
hippocampus in this group revealed picnotic nuclei, vacuolar degeneration and neuronal loss.
Immunostaining showed areas with significantly increased GFAP immunopositivity. Concomitant
administration of GBE with FA resulted in a significant increase in antioxidant enzymes activity (SOD,
GSH-Px and CAT), decreased MDA, and improvement of histopathological changes induced by FA.
Also a significant reduction in expression of GFAP was observed. It was concluded that short term
administration of FA induced neurotoxicity on the hippocampus of adult male albino rats, with oxidant
stress and lipid peroxidation which may be a molecular mechanism involved in FA induced
neurotoxicity. Furthermore, these effects were decreased by the concomitant use of GBE. It is
recommended to use GBE for amelioration of toxic manifestations of formaldehyde in exposed
population.