Mehtap Erdogan; Tuncay Colak; Fatma Sureyya Ceylan; Hale Maral Kır; Sema Kurnaz; Ozgur Doga Ozsoy & Zuhal Sahin

Formaldehyde induces oxidative damage in hippocampal tissue and blood serum by suppressing antioxidant defenses and increasing lipid peroxidation. This results in damage to DNA, proteins, and lipids within cells, disrupting neuronal functions, and may even lead to cell death (apoptosis). Apoptosis occurs as a cellular response triggered by formaldehyde through various mechanisms, including mitochondrial dysfunction, oxidative stress, and DNA damage. Arbutus unedo L. (AUL), which is rich in antioxidants, represents a potential countermeasure. The aim of our study is to investigate the immunohistochemical and biochemical effects of AUL fruit extract (AUE) on apoptosis and oxidative stress induced by FA exposure in the rat hippocampus. The rats were divided into four groups: the experimental group (EG) received 20 mg/kg AUE by oral gavage and 10 ppm FA inhalation; the formaldehyde group (FG) received 10 ppm FA inhalation only; the sham group (SG) received 10 mg/kg AUE by oral gavage; and the control group (CG) underwent routine observation. Hippocampal tissue was isolated after blood sampling. A number of physical changes, such as yellowing of feathers and tail spots, were observed in FA-exposed groups. The biochemical analysis showed significant differences in brain-derived neurotrophic factor (BDNF), malondialdehyde (MDA), GSH (Glutathione) and nitric oxide (NO) levels between the groups. The AUE-treated groups had reduced MDA levels, suggesting a potential reduction in oxidative stress, along with lower apoptotic cell rates in caspase-3 assessments. The FG rats had lower BDNF levels than CG. The SG had the fewest apoptotic cells. All these findings indicate AUE's potential to mitigate neuron damage and reduce oxidative stress.

KEY WORDS: Apoptosis; Arbutus unedo L; Formaldehyde; Hippocampus; Oxidative stress.

ERDOGAN, M.; COLAK, T.; CEYLAN, F. S.; KIR, H. M.; KURNAZ, S.; OZSOY, O. D. & SAHIN, Z. Neuroprotective Activity of Strawberry Tree (Arbutus unedo L.) Against formaldehyde-induced oxidative stress in the rat hippocampus. Int. J. Morphol., 42(5):1338- 1346, 2024.