Anti-oxidative effect of Salvia miltiorrhiza Bunge fermented with Shiraia bambusicola Henn. against H2O2-induced injury in PC12 cells.

Abstract

Purpose: The objective of this investigation was to produce fermented solid-state products of Salvia miltiorrhiza Bunge (SMB) utilizing Shiraia bambusicola Henn. (FSSMB). Additionally, it was intended to further explore toxicity-reducing potential and antioxidant effects of FSSMB ethanol extract against H₂O₂-induced oxidative stress in rat pheochromocytoma cell line 12 (PC12).

Methods: PC12 cells were pre-treated with SMB or FSSMB ethanol extract for 24 h, followed by exposure to 1 mmol/L H₂O₂ for 3 h to induce oxidative stress. Subsequently, the cell viability, reactive oxygen species (ROS) level, malondialdehyde (MDA) content, superoxide dismutase (SOD) activity, p-p38/p38 and p-JNK/JNK proteins were assessed. Additionally, the content of antioxidant, including tanshinones (tanshinone I, tanshinone IIA, dihydrotanshinone, and cryptotanshinone) and salvianolic acids (danshensu, rosmarinic acid, lithospermic acid, and salvianolic acid B) were quantified by HPLC in SMB and FSSMB.

Results: Here, we found that FSSMB exhibited lower cytotoxicity compared to SMB in PC12 cells, and FSSMB instead of SMB significantly increased cell viability in H₂O₂-induced PC12 cells. Notably, FSSMB exhibited superior antioxidant properties in H₂O₂-induced PC12 cells, as evidenced by reduced levels of ROS, MDA, and enhanced SOD activity compared to SMB. Mechanistically, FSSMB reversed H₂O₂-induced increase of phosphorylation of p38 and JNK protein in mitogen-activated protein kinase (MAPK) signaling pathway, thereby protecting PC12 cells from oxidative stress-induced injury. Furthermore, we found a significant increase of tanshinone IIA and cryptotanshinone content, accompanied by decreased levels of tanshinone I, dihydrotanshinone and salvianolic acids in FSSMB compared to SMB.

Conclusions: Our study explores a new biological transformation approach through solid-state fermentation (SSF) with Shiraia bambusicola Henn. on SMB. This study demonstrated that the SSF may reduce the cytotoxicity and enhance the antioxidant capacity of SMB in PC12 cells, thus paving the way for safer and more efficacious applications in the future. FSSMB may be an effective substitute for traditional Chinese medicine SMB for resistance to oxidative stress.