Water Extract of Rhei Rhizoma Prevent Production of Reactive Oxygen Species and Loss of Mitochondrial Membrane Potential in a Hypoxia Model of Cultured Neurons

Abstract

Rhei Rhizoma (RR; 大黃) consists of the underground parts (rhizome and root) of Rheum officinale Baill. and Rheum palmatum L. (Polygonaceae), and is widely used in Southeast Asian folk medicine to alleviate liver and kidney damages. In this study, we investigated into the efficacy and mechanism of RR water extract in supporting neuronal survival in a hypoxia model of cultured rat hippocampal neurons. RR exhibited no cytotoxicity up to 10 μg/ml and exhibited neurosupportive effects at 2.5 μg /ml in normoxia. When RR was added to the culture media on 10 days in vitro (DIV10) and given a hypoxic shock (2% O2/5% CO2, 3 hr, 37 o C) on DIV13, RR exhibited neuroprotective effects on 5 days post-shock. H2DCF stainings indicated that RR effectively prevents ROS production in both normoxia and hypoxia. JC-1 stainings showed that RR prevents dissipation of MMP in hypoxia. These results indicate that RR protects neurons by suppressing ROS production and MMP loss.

Microarray Analysis of Gene Expression by Rhei Rhizoma Water Extracts in a Hypoxia Model of Cultured Neurons

“…However, effects of RR on the nervous system are not studied at the cellular level. Previously, our laboratory reported that RR suppresses production of reactive oxygen species (ROS) and loss of mitochondrial membrane potential (MMP) in a hypoxia model of rat hippocampal neurons in culture [34]. Here, we report results of a microarray analysis on the expression of genes in hypoxia.…”