Altered Micro-RNA Regulation and Neuroprotection Activity of Eremostachys labiosiformis in Alzheimer's Disease Model.

Amyloid-β peptide (Aβ) is involved in the formation of senile plaques in Alzheimer's disease (AD), and causes neuronal cell death by inducing oxidative stress.

We investigated the protective effect of Eremostachys labiosiformis extract against the Aβ-induced toxicity in SH-SY5Y cells.

Methanolic extract from the aerial parts of E. labiosiformis was prepared by percolation method at room temperature. SH-SY5Y cells were treated and incubated with different concentrations of the extract for 1 h, before addition of Aβ. Cytotoxicity was measured 24 h after the addition of Aβ to the medium using MTT and reactive oxygen species (ROS) assays. Effective doses were evaluated using real-time polymerase chain reaction to evaluate expression of miR-212 and miR-132. The results were analyzed using SPSS software (16).

Exposure of -SH-SY5Y cells to Aβ significantly affected the viability of cells and increased ROS levels. The results revealed that 1.2 and 2.5 μg/mL of the E. labiosiformis extract reduced Aβ-induced deterioration. Only 2.5 μg/mL of the extract could reduce ROS levels. In addition, 5 μg/mL of the extract increased the expression of the miRNAs, which was reduced after exposure to Aβ.

Based on the antioxidant and protective effects of the E. labiosiformis extract on expression of miR-132 and miR-212 and ROS level, this herb could be used as a suitable candidate for future studies on neurodegenerative diseases including AD.