Ginsenoside Rh3-induced neurotoxicity involving the IP3R-Ca2+/NOX2/NF-κB signaling pathways

Abstract

Ginsenoside Rh3, a bioactive component of ginsenosides, has gained attention for its potential therapeutic effects, especially in cancer treatment. However, its neurotoxic effects remain poorly characterized, raising concerns about its safety for clinical use. This study investigates the neurotoxic effects of ginsenoside Rh3 and explores the underlying mechanisms. We demonstrate that ginsenoside Rh3 induces significant cytotoxicity in Neuro-2a and C8-D1A cells, as confirmed by methyl thiazolyl tetrazolium (MTT) assays, live-dead staining, and lactate dehydrogenase (LDH) release assays. Neurotoxicity polymerase chain reaction (PCR) array analyses show that the cytotoxicity of ginsenoside Rh3 in Neuro-2a cells involves calcium ion transport, oxidative stress, inflammation, and programmed cell death (PCD). Specifically, ginsenoside Rh3 elevates intracellular Ca²⁺ levels by activating the inositol 1,4,5-triphosphate receptor (IP3R), which in turn increases oxidative stress via nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) 2. This cascade activates the phosphorylated nuclear factor-kappa B (NF-κB) signaling pathway, exacerbating apoptosis and leading to neuronal cell death. Molecular docking and dynamics simulations suggest direct interactions between ginsenoside Rh3 and both IP3R and NOX2. Notably, the neurotoxic effects of ginsenoside Rh3 were significantly attenuated by IP3R inhibitor 2-aminoethyl diphenylborinate (2-APB) and NOX2 inhibitor GSK2795039. These findings demonstrate that ginsenoside Rh3 induces neurotoxicity through IP3R-Ca²⁺/NOX2/NF-κB signaling pathways. This study provides critical insights into the safety concerns of ginsenoside Rh3, highlighting the need for caution in its clinical applications.

Keywords: Apoptosis; Ginsenoside Rh3; IP3R-Ca2+; NOX2; Neurotoxicity; Oxidative stress.