Salvianic borneol ester reduces β-amyloid oligomers and prevents cytotoxicity

Abstract

Context: The destabilization of β-amyloid (Aβ) peptide aggregates and the protection of functional cells are the attractive therapeutic strategies for Alzheimer’s disease (AD). Some active ingredients of Salvia miltiorrhiza f. alba C.Y.Wu & H.W.Li (Lamiaceae) (SM) have attracted increasing attention for the treatment of neurodegenerative diseases.

Objective: Salvianic borneol ester (SBE) is a new compound based on SM formulas. The present study was designed to examine the anti-amyloid effects and neuroprotection of SBE in vitro.

Materials and methods: The destabilizing effects of SBE and its related compounds (salvianic acid A and borneol) on preformed Aβ oligomers were measured by using fluorescence spectroscopy with thioflavin T (ThT) and the destabilizing effects of SBE were further confirmed visually by transmission electron microscopy (TEM). The neuroprotective effects of SBE against hydrogen peroxide (H₂O₂)-induced toxicity in human neuroblastoma cells (SH-SY5Y) and motor neuron hybridoma cells (VSC 4.1) were shown by MTT assay and morphological observation.

Results: SBE showed the most significant destabilizing effect, though the mixture of salvianic acid A and borneol also destabilized Aβ1–40 oligomers. The destabilizing activity of salvianic acid A or borneol alone was not significant. SBE destabilized Aβ1–40 oligomers in dose- and time-dependent manners and the destabilizing effect could also be seen in the photographs of TEM. Furthermore, SBE could protect SH-SY5Y cells and VSC 4.1 cells against H₂O₂-induced toxicity in a dose-dependent manner.

Discussion and conclusion: SBE had the bifunctional activities of anti-amyloid and neuroprotection. It may have therapeutic potential for AD and be an alternative lead compound for developing new drugs against AD.

Keywords::

• Alzheimer’s disease
• β-amyloid peptide
• neuroprotection
• salvianic borneol ester
• thioflavin T
• transmission electron microscopy

Acknowledgements

This work was supported by the National Natural Science Foundation of China (30672491) and by the Beijing New Medical Discipline Based Group (XK100270569). We are grateful to Prof. Xiaohui Zheng for generously providing SBE.

Declaration of interest

There is no conflict of interest to declare.