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

Abstract

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.