Safety assessment of the Quercus brantii gall hydroalcoholic extract: Single and repeated oral dose toxicity studies

Objective(s): Quercus brantii galls (QBGs) are well-known in Iranian traditional medicine for treating various diseases. The aim of study was to assess the acute and repeated oral toxicity of the hydroalcoholic extract of QBG in female rats.Materials and Methods: The ethanolic extract of QBG was administered in rats by gavage in both acute and repeated dose models. In the acute section of the study, a single oral dose of ۲۰۰۰ mg/kg was administered to female rat which were observed for physical symptoms and behavioral changes for ۱۴ days. In the repeated dose toxicity study, the QBG extract (۵۰, ۵۰۰, and ۱۰۰۰ mg/kg/day) was administered for a period of ۲۸ days to rats. On ۲۸th day of experiment, blood sampling of animals was done for hematological and biochemical analysis and then sacrificed for histopathological examination of the harvested tissues (liver, heart, kidney, lung, spleen, stomach, ovary and uterus).Results: A single oral administration of the QBG extract (۲۰۰۰ mg/kg) did not produce mortality or significant behavioral changes during ۱۴ days of observation. In repeated oral toxicity models, the extract significantly increased (P<۰.۰۵) the levels of mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), thyroid-stimulating hormone (TSH) and significantly decreased the levels of triiodothyronine (T۳) and thyroxin (T۴) in ۵۰۰ and ۱۰۰۰ mg/kg dosage. The histopathological studies showed the absence of toxic effects of QBG (۵۰ mg/kg dosage) and revealed evidence of microscopic lesions in the liver, kidney, stomach, heart, spleen, lung, uterus, and ovary in the ۵۰۰- and ۱۰۰۰-mg/kg groups. Conclusion: The results indicate that the oral acute toxicity of QBG extract was of a low order with LD۵۰ being more than ۲۰۰۰ mg/kg in rats. In addition, slight tissue damage was observed in some tissues in the ۵۰۰ and ۱۰۰۰ mg/kg groups. It was found that prolonged use at higher doses i.e. ۵۰۰ mg/kg/day of QBG extract should be avoided.

Keywords:

acute toxicity , Quercus , Quercus brantii gall , Rat , Repeated dose toxicity , Toxicity studies