OBJECTIVE To explore the protective effect of the Pimpinella diversifolia stem essential oil(PDSEO) on lipopolysaccharide(LPS)/D-galactosamine(D-GalN) induced acute liver injury in mice and its possible molecular mechanism.

METHODS PDSEO was prepared through the simultaneous distillation and extraction method and its chemical composition were identified by GC/MS. The acute liver injury model was established using LPS/D-GalN as the inducer. The serum levels of ALT, AST, and ALP were determined, and the serum levels of inflammatory factors were analyzed by cytometric bead array assay(CBA). The pathological changes of liver tissues were analyzed by HE staining. The level of malondialdehyde(MDA) was detected using liver tissue homogenates. The expression levels of genes related to inflammatory factors and antioxidant enzymes in liver tissues were analyzed by fluorescence quantitative PCR. The apoptosis of hepatocytes was analyzed by the TUNEL method. The hepatoprotective activity and mechanism of PDSEO were comprehensively evaluated.

RESULTS A total of 46 components of PDSEO were identified, among which 34 were terpenoids. Both low(50 mg·kg⁻¹) and high(100 mg·kg⁻¹) doses of PDSEO could conspicuously reduce the elevation of serum ALT, AST and ALP induced by LPS/D-GalN. It could also efficaciously decrease the expression of inflammatory genes IL-6, TNF-α and MCP-1 in liver tissue as well as the level of serum inflammatory factors. After the treatment with low and high doses of PDSEO, the expression of anti-oxidation-related genes such as SOD1, SOD2, CAT and Gpx4 in liver tissue was up-regulated. Meanwhile, the activities of SOD and CAT enzymes and the GSH levels in liver tissue were significantly augmented, while the lipid peroxidation product MDA was significantly diminished. HE and TUNEL apoptotic staining of liver tissue sections further confirmed that both the low and high dose PDSEO groups could effectively alleviate hepatocyte apoptosis and liver tissue injury.

CONCLUSION The stems of Pimpinella diversifolia abound in essential oil, which is capable of suppressing excessive inflammation of liver tissue, enhancing the level of the antioxidant system, alleviating the emergency response of excessive oxidation of liver tissue, decrease liver cell apoptosis, effectively mitigating LPS/D-GalN-induced acute liver injury in mice, and demonstrating potential development and utilization value in the development of drugs for preventing liver tissue injury.