Study of in vitro cytotoxicity of arsenocholine, a trimethyl arsenic compound in seafood

Abstract

Study ofWe examined the in vitro cytotoxic effects of an organic arsenic compound contained in seafood, viz. the trimethyl (2-hydroxyethyl)-arsonium cation, or arsenocholine (AsCho), on some murine immune effector cells, such as splenocytes, thymocytes, Peyer's patch lymphocytes, peritoneal macrophages and bone marrow (BM) cells using synthesized pure material. We found that AsCho had no cytotoxicity on most immune effector cells, even at concentrations over 10 mmol dm À3 , and it slightly but significantly enhanced the viability of BM cells at doses over 100 mmol dm À3. This biological effect of AsCho on BM cells might be direct rather than due to autocrine mechanisms mediating some factors secreted by AsCho-stimulated BM cells, because the culture supernatants of BM cells pre-stimulated with AsCho did not influence the viability of other fresh BM cells. It is interesting that this unique biological effect was found in AsCho, an organic arsenic compound contained in some marine animals that are ingested daily as seafood in many countries.

Review: Biological effects of organic arsenic compounds in seafood

“…Interestingly, it slightly augmented the viability of bone marrow cells (about a 1.3-fold increase in the viability of cells compared with that of control cells during a 72 h incubation) at high concentrations over 100 mmol dm À3 . 33 As described below, this unique biological action was also found to be more effective with AsBe, but was not observed for any other arsenic compounds. 28 Marafante et al 34 and Kaise et al 31 examined the metabolism of AsCho and reported that it was converted to AsBe and rapidly excreted into the urine after oral administration; however, we found that AsCho was not converted into any other arsenicals, including AsBe, in murine bone marrow cells in vitro.…”

“…As described above, the AsBe-induced weak modulating effect on the survival of bone marrow cells was observed with AsCho, which has a chemical structure similar to that of AsBe. 33 Additionally, this biological effect was not observed with any other methyl arsenic compounds, such as monomethylarsonic acid, dimethylarsinic acid 38 and tetramethylarsonium hydroxide. 27 It is very interesting that this unique biological effect was found with AsBe, a major arsenic compound contained in large quantities in the various marine animals ingested daily as seafood in many countries.…”

“…28 Marafante et al 34 and Kaise et al 31 examined the metabolism of AsCho and reported that it was converted to AsBe and rapidly excreted into the urine after oral administration; however, we found that AsCho was not converted into any other arsenicals, including AsBe, in murine bone marrow cells in vitro. 33 It is likely that the increasing effect of AsCho on the viability of bone marrow cells is due to the chemical structure of AsCho.…”

Evaluation ofin vivo acute immunotoxicity of arsenocholine, a trimethyl arsenic compound in seafood

“…5,6 It was reported that AsCho had a weak, but significant, in vivo acute toxicity in mice, 7 but we recently demonstrated that AsCho had no in vitro cytolethality on cultured mouse splenocytes, thymocytes, Peyer's patch lymphocytes, macrophages and bone marrow cells. 1,8,9 In this study, we examined whether AsCho has any in vivo immunotoxicity, and found that it was slightly, but significantly, immunotoxic in vivo.…”

“…7 In contrast, we recently observed that AsCho did not show any cytolethality in cultured mouse immune effector cells, such as macrophages, splenocytes, thymocytes, Peyer's patch lymphocytes and bone marrow cells, in vitro. 1,8,9 In this study, we examined whether AsCho has any in vivo immunological effects using mouse models, and found that AsCho had weak immunotoxicity when administered orally.…”