Revista de patología clínica y experimental

Abstracto

Histopathological and Biochemical Assessment of Chronic Oral Administration of Aqueous Leaf Extract of Thymus Serrulatus in Mice

Nigatu Debelo, Mekbib Afework, Asfaw Debella, Eyasu Makonnen, Wondwossen Ergete and Bekesho Geleta

Background: Medicinal plants are the source of treatment for many diseases throughout the developing world. The provision of safe herbal therapies could, thus, become a critical tool to increase access to health care in minimizing the undesirable effects. Thymus serrulatus is among commonly used herbal remedy in Ethiopia in addition to its use for spicing a food and as infusion in tea. This study was designed to investigate toxic effects of the aqueous leaf extract of Thymus serrulatus in mice.

Methods: In this study, the mice were randomly divided into control and treatment groups that received distilled water and oral administration of single dose of 300, 2000, 5000 and 10,000 mg/kg (n=5) extract for acute toxicity, respectively and followed for 14 days. The chronic toxicity was evaluated through daily oral administration of extracts at doses of 200 and 600 mg/kg for 90 days in mice (n=6). On the 91st day, blood samples were collected for hematological and biochemical analysis. Liver and kidney were harvested for histopathological examination by tissue section preparation and microscopic examination.

Results: The acute toxicity study found no signs of toxicity; hence LD50 was greater than 10,000 mg/kg. After 90 days of extract administration, there was no significant change in body weight, and most of the evaluated hematological and biochemical parameters. There was a significant decrease in count of basophils in male mice treated at dose 600 mg/kg. In addition, creatinine level of female mice at both doses was also significantly reduced. No death was recorded, and body weight change remained normal compared to the control. In gross observations, the kidneys and liver appear normal compared to the control. Histopathological examination of liver and kidney were essentially normal.

Conclusions: Thymus serrulatus is relatively safe. However, mild mononuclear leukocytic infiltration was observed in mice treated at higher doses.