Hepatoprotective effects of ethanol extracts from Folium Syringae against acetaminophen-induced hepatotoxicity in vitro and in vivo.

Background: The leaves of Folium Syringae (FS) have been long used as a traditional Chinese folk medicine for their anti-inflammatory effect, utilized as an antibacterial and antiviral treatment. The purpose of this study was to investigate the potential hepatoprotective effects of FS on acetaminophen-induced hepatic injury in primary hepatocytes and mice.

Methods: Hepatocytes obtained by the inverse perfusion method were divided randomly into five groups. Prior to acetaminophen exposure, 3 different doses of FS ethanol extracts were given to hepatocytes and mice, respectively. Thereafter, transaminases, glutathione S-transferase A1 (GSTA1) and some hepatic indices were determined.

Results: FS ethanol extracts (200 μg/mL) pretreatment prevented all of the alterations, returning their levels to nearly those levels observed in the control group in vitro. Treatment with FS ethanol extracts (200 mg/kg) significantly reduced the toxicity induced by acetaminophen in vivo, which manifested as a decrease in transaminases, and the hepatoprotective effects of FS were similar to Silymarin (positive group). GSTA1 represented the same change trend as transaminases and hepatic indices, and at a dose of 100 μg/mL FS ethanol extracts in vitro and 100 mg/kg in vivo, GSTA1 content changed significantly (p < 0.01), but transaminases were insignificant (p > 0.05).

Conclusion: The results of our investigation suggested that FS ethanol extracts possess significant protective effects against hepatotoxicity induced by acetaminophen both in vitro and in vivo. In addition, GSTA1 could be used as an indicator assessing the extents of hepatic injury, which is more sensitive than transaminases.