Evacuation the Effect of Single- and Multi-dose Administration of Ethanolic Extract of Pinus eldarica Pollen Against Acetaminophen-induced Rat Liver Injury

Introduction: Acetaminophen (APAP)-induced liver injury is one of the main causes of acute liver failure in the world. Pinus eldarica is specially distributed in the north of Iran and has been used for decades to treat wounds, pain, infection, fever, bronchitis and inflammation in many countries. This study was undertaken to evaluate the role of pine pollen extract (PE) on APAP-induced hepatotoxicity. Methods: This study was conducted in two separate parts: single- and multi- dose administration of PE. In a multiple dosing regimen, different doses of extract (10, 20, 30, 40 and 50 mg/kg) were orally administrated for 2 weeks and then on the 15th day, the animals received a single dose of APAP (600 mg/kg). In the second part, the highest dose of PE (50 mg/kg) was orally administrated half an hour after receiving the APAP at dose of 600 mg/kg. The negative and positive control groups were treated with normal saline and N-acetylcysteine (NAC), respectively. At the end of procedure, the biochemical parameters including alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP) as well as pathological findings were evaluated. Results: A single and multiple oral dose of APAP increased the serum level of ALT, AST and ALP that were significantly attenuated by PE administration in both model. Indeed, exposure to APAP caused extensive necrosis and lymphocytic inflammation that were completely prevented by single- and multi-dose administration of PE, specially at a high dose. Conclusion: Finally, the present results indicate that PE could reverse the reduction of aminotransferases and improve histological changes of APAP-induced liver toxicity. Further research is needed to confirm this finding and reveal the exact mechanisms.