Paeoniflorin Alleviates H2O2-Induced Oxidative Injury Through Down-Regulation of MicroRNA-135a in HT-22 Cells.

Paeoniflorin (PF) has been reported to possess neuroprotective influences on cognitive dysfunction illness. In current research, we attempted to probe into the protective influences of PF against H2O2-induced damage and the underlying regulating mechanisms on hippocampal HT-22 cells. HT-22 cells were pretreated with PF, and then induced by H2O2. Afterwards, the influences of PF pretreatment were examined using CCK-8 assay, apoptosis assay, western blot and ROS assay, respectively. In addition, the expression of microRNA-135a (miR-135a) was analyzed and altered by qRT-PCR and cell transfection, respectively. After overexpression of miR-135a, the effects of miR-135a mimic on cell functions were detected again. Moreover, influences of H2O2, PF and miR-135a overexpression on JAK2/STAT3 and ERK1/2 signal pathways were further investigated. Further experiments verified that PF pretreatment alleviated H2O2-induced oxidative stress through increasing cell viability, inhibiting cell apoptosis, reducing ROS generation and activating JAK2/STAT3 and ERK1/2 pathways. Besides, expression of miR-135a was declined by PF pretreatment. Whereas, miR-135a mimic abrogated the protective effects triggered by PF pretreatment. These results indicated that PF can alleviate H2O2-induced oxidative stress by down-regulation of miR-135a via activation of JAK2/STAT3 and ERK1/2 pathways.