In vitro genotoxicity of carcinogenic asarone isomers

Abstract

The present study focused on genotoxic properties of the carcinogenic phenylpropanoids α-asarone and β-asarone, which are found in several herbs and spices, such as Acorus calamus or Acorus gramineus. Cytotoxic and genotoxic effects were determined in human liver carinoma HepG2 cells, in hamster lung fibroblast V79 cells and in human cytochrome P450 1A2 and human sulfotransferase 1C2 transfected V79 cells (tV79). The Alamar blue assay was used to measure cytotoxicity of both isomers prior to the identification of DNA damaging properties by single cell gel electrophoresis (comet assay). Furthermore, the phosphorylation status of the histone H2AX, as a response of DNA double strand breaks, was investigated in HepG2 cells by Western blot analysis and visualized by immunofluorescence microscopy. After 24 h of incubation a significant reduction of cell viability was found. Moreover, both asarone isomers induced DNA strand breaks in V79 cells after 1 h of incubation. In tV79 cells even more pronounced DNA damaging properties were exhibited, whereas in HepG2 cells the compounds were found to be less effective. Furthermore, in tV79 cells a significant increase of formamidopyrimidine-DNA-glycosylase-sensitive sites was observed. DNA strand breaks, induced by aA, were to some extent characterized as DNA double strand breaks. In summary, asarone-induced cytotoxicity and genotoxicity is strongly influenced by the cellular metabolic enzyme status and therefore, a contribution of their respective metabolites to in vitro toxicity can be suggested.

Combined application of tenuigenin and β-asarone improved the efficacy of memantine in treating moderate-to-severe Alzheimer’s disease

“…6) Although no hepatomas, mutagenesis, genotoxicity, and teratogenicity were identified in patients receiving β-asarone, future studies should consider the risk of these adverse events. 41 – 43 7) This was a preliminary study, so the long-term effects of this novel method were not evaluated. Future large-scale, multicenter, randomized studies are needed to solve these limitations.…”

α‐Asarone, β‐asarone, and γ‐asarone: Current status of toxicological evaluation

“…In comparison with mutagenicity testing in bacteria, genotoxicity testing is reported to a lesser extent (Devi, Babu, & Premkumar, 2014; Hasheminejad & Caldwell, 1994; Haupenthal et al, 2017; Kevekordes et al, 2001; Marczewska et al, 2013; Morales‐Ramírez et al, 1992; Ramos‐Ocampo & Hsia, 1988; Unger & Melzig, 2012). Results for unscheduled DNA synthesis (UDS), sister chromatid exchange (no longer part of the testing strategy of the OECD guidelines), micronucleus test, and comet assay are available and were summarized in Tables 5 and 6.…”

“…Positive results for SCE were not considered in a weight of evidence approach because this test was withdrawn from OECD test guidelines. DNA strand breaking properties occurred as an early event in Chinese Hamster fibroblasts V79, in V79 cells transfected with human enzymes for metabolic competency (V79‐hCYP1A2‐hSULT1C2), and in human liver hepatoblastoma cell line HepG2 after 1‐hour incubation with non‐cytotoxic concentrations ≤100 μM (Haupenthal et al, 2017). A contribution of redox‐sensitive mechanisms to DNA‐damaging properties can be proposed from observed formamidopyrimidine‐DNA‐glycosylase‐sensitive sites after metabolic activation.…”

Phase II Metabolism of Asarone Isomers In Vitro and in Humans Using HPLC-MS/MS and HPLC-qToF/MS

“…Besides all positive effects, these substances are also of toxicological concern. Among acute and chronic toxicity, hepatotoxic properties in rodents as well as cytotoxic, genotoxic and mutagenic effects in vitro are reported for parent compounds and several oxidative phase I metabolites [ 7 , 8 , 9 , 10 , 11 ]. Furthermore, DNA repair mechanisms are also activated in response to asarone-mediated genotoxic effects in cells [ 10 ].…”