Hepatoprotective standardized EtOH-water extract from the seeds of Fraxinus rhynchophylla Hance

Abstract

Fraxinus rhynchophylla Hance (Oleaceae), its stem barks are known as Cortex fraxini ( qín pí) listed in Chinese Pharmacopoeia. Phytochemical study has indicated that methanol extracts from Qinpi has protective effect on acute liver injury. The present study investigates the hepatoprotective activity of EtOH-water extract from the seeds of F. rhynchophylla Hance against carbon tetrachloride-induced liver injury in mice. The EtOH-water extract significantly alleviated liver damage as indicated by the decreased levels of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), the malondialdehyde (MDA) content, and increased the levels of superoxide dismutase (SOD), glutathione (GSH) and glutathione peroxidase (GSH-Px), and reduced the pathological tissue injury induced by CCl₄. Quantitative analysis of seven major constituents (1-7) in EtOH-water extract (EWE) was developed by high performance liquid chromatography-diode-array detector (HPLC-DAD). The current research indicates that the EWE from the seeds of F. rhynchophylla Hance decreased liver index, inhibited the increase of serum aminotransferase induced by CCl₄, and decreased hepatic MDA content, SOD and GSH-Px activities. These results suggested that the pretreatment with EWE protected mice against CCl₄-induced liver injuries. Based on the results, the EtOH-water extract from the seeds of F. rhynchophylla Hance is efficacious for prevention and treatment of CCl₄-induced hepatic injury in mice. Secoiridoid and tyrosol glucosides might be the active ingredients responsible for the biological and pharmacological activities of hepatoprotection.

Keywords: ALT and AST; CCl4-induced hepatic injury mice; Fraxinus rhynchophylla Hance; Hepatoprotective; Secoiridoid glucosides.

Graphical abstract

Fig. 1

Structures of compounds 1–7.

Fig. 2

The HPLC chromatogram of EtOH–Water extract.

Fig. 3

Effects of EWE on liver index. Different lower case letters correspond to significant differences at P < 0.05. Group I was the control group. Group II was CCl₄-treated group. Group III was given CCl₄ + silymarin. Group IV and V were given CCl₄ + 2.0 and 4.0 g/kg BW of EWE respectively.

Fig. 4

Effects of EWE on serum ALT and AST. Different lower case letters correspond to significant differences at P < 0.05. Group I was the control group. Group II was CCl₄-treated group. Group III was given CCl₄ + silymarin. Group IV and V were given CCl₄ + 2.0 and 4.0 g/kg BW of EWE respectively.

Fig. 5

Effects of EWE on hepatic MDA. Different lower case letters correspond to significant differences at P < 0.05. Group I was the control group. Group II was CCl₄-treated group. Group III was given CCl₄ + silymarin. Group IV and V were given CCl₄ + 2.0 and 4.0 g/kg BW of EWE respectively.

Fig. 6

Effects of EWE on hepatic SOD activity. Different lower case letters correspond to significant differences at P < 0.05. Group I was the control group. Group II was CCl₄-treated group. Group III was given CCl₄ + silymarin. Group IV and V were given CCl₄ + 2.0 and 4.0 g/kg BW of EWE respectively.

Fig. 7

Effects of EWE on hepatic GSH-Px activity. Different lower case letters correspond to significant differences at P < 0.05. Group I was the control group. Group II was CCl₄-treated group. Group III was given CCl₄ + silymarin. Group IV and V were given CCl₄ + 2.0 and 4.0 g/kg BW of EWE respectively.

Fig. 8

Effects of EWE on hepatic morphological analysis (×200 H&E): control mice (A), CCl₄-treated mice (B), mice pretreated with silymarin prior to CCl₄ (C), mice pretreated with 2.0 (D) and 4.0 g/kg (E) BW of EWE respectively prior to CCl₄. (➝ dilated sinusoidal spaces, ⇨ inflammatory cell infiltration).