Ginsenoside Rg1 Reduces Cardiotoxicity While Increases Cardiotonic Effect of Aconitine in vitro

Abstract

Objective: To explore the synergic mechanism of ginsenoside Rg₁ (Rg₁) and aconitine (AC) by acting on normal neonatal rat cardiomyocytes (NRCMs) and pentobarbital sodium (PS)-induced damaged NRCMs.

Methods: The toxic, non-toxic, and effective doses of AC and the most suitable compatibility concentration of Rg₁ for both normal and damaged NRCMs exposed for 1 h were filtered out by 3- (4,5)-dimethylthiahiazo (-z-y1)-3,5-diphenytetrazoliumromide, respectively. Then, normal NRCMs or impaired NRCMs were treated with chosen concentrations of AC alone or in combination with Rg₁ for 1 h, and the cellular activity, cellular ultrastructure, apoptosis, leakage of acid phosphatase (ACP) and lactate dehydrogenase (LDH), intracellular sodium ions [Na⁺], potassium ions [K⁺] and calcium ions [Ca²⁺] levels, and Nav1.5, Kv4.2, and RyR₂ genes expressions in each group were examined.

Results: For normal NRCMs, 3000 µ mol/L AC significantly inhibited cell viability (P<0.01), promoted cell apoptosis, and damaged cell structures (P<0.05), while other doses of AC lower than 3000 µ mol/L and the combinations of AC and Rg₁ had little toxicity on NRCMs. Compared with AC acting on NRCMs alone, the co-treatment of 3000 and 10 µ mol/L AC with 1 µ mol/L Rg₁ significantly decreased the level of intracellular Ca²⁺ (P<0.01 or P<0.05), and the co-treatment of 3000 µ mol/L AC with 1 µ mol/L Rg₁ significantly decreased the level of intracellular Ca²⁺ via regulating Nav1.5, RyR₂ expression (P<0.01). For damaged NRCMs, 1500 µ mol/L AC aggravated cell damage (P<0.01), and 0.1 and 0.001 µ mol/L AC showed moderate protective effect. Compared with AC used alone, the co-treatment of Rg₁ with AC reduced the cell damage, 0.1 µ mol/L AC with 1 µ mol/L Rg₁ significantly inhibited the level of intracellular Na⁺ (P<0.05), 1500 µ mol/L AC with 1 µ mol/L Rg₁ significantly inhibited the level of intracellular K⁺ (P<0.01) via regulating Nav1.5, Kv4.2, RyR₂ expressions in impaired NRCMs.

Conclusion: Rg₁ inhibited the cardiotoxicity and enhanced the cardiotonic effect of AC via regulating the ion channels pathway of [Na⁺], [K⁺], and [Ca²⁺].

Keywords: aconitine; cardiomyocytes; compatibility; ginsenoside Rg1; ion channel pathway.