J Korean Med Sci.  2012 Jan;27(1):3-9. 10.3346/jkms.2012.27.1.3.

Cellular Toxicity of Surfactants Used as Herbicide Additives

• Song HY
• Kim YH
• Seok SJ
• Gil HW
• Yang JO
• Lee EY
• Hong SY

• KMID: 1792971
• DOI: http://doi.org/10.3346/jkms.2012.27.1.3

Abstract

The cellular toxicities of surfactants, a solvent, and an antifreeze that are included in herbicide formulations were assessed by measuring their effects on membrane integrity, metabolic activity, mitochondrial activity, and total protein synthesis rate in a cell culture. Polyethylene glycol, propylene glycol, and monoethylene glycol exhibited no cellular toxicity even at a high concentration of 100 mM. Sodium lauryl ether sulfate and polyoxyethylene lauryl ether significantly damaged the membrane, disturbed cellular metabolic activity, and decreased mitochondrial activity and the protein synthesis rate; however, their toxicity was far below those of the severely toxic chemicals at comparable concentrations. The severely toxic category included polyoxypropylene glycol block copolymer, polyoxyethylene tallow amine, and polyoxyethylene lauryl amine ether. These surfactants were cytotoxic between 3.125 microM and 100 microM in a dose-dependent manner. However, the toxicity graph of concentration vs toxicity had a point of inflection at 25 microM. The slope of the toxicity graph was gentle when the concentration was below 25 microM and steep when the concentration was greater than 25 microM. In conclusion, our results suggest that the toxicity of surfactants be taken care of pertinent treatment of acute herbicide intoxication.

Keyword

Acute Poisoning; Herbicide; Surfactant; Cytotoxicity

MeSH Terms

Animals
Cell Line
Cell Membrane/drug effects
Herbicides/*chemistry
Mice
Mitochondria/drug effects
Polyethylene Glycols/toxicity
Sodium Dodecyl Sulfate/toxicity
Surface-Active Agents/chemistry/*toxicity
Toxicity Tests

Figure

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  Fig. 1 Overall cell viability in the presence of each chemical between 500 µM and 500 mM. Note the non-toxicity of PEG 300 (an antifreeze), PG, and MEG (solvents); mild toxicity of SLES (an anionic surfactant) and LE-2 (a nonionic surfactant); and severe toxicity of TN-20, LN-10, and PE-61 (nonionic surfactants).

• 

  Fig. 2 Effects of the tested compounds on membrane integrity (extracellular lactate dehydrogenase [LDHe]), metabolic activity (glucose [GLU]), mitochondrial activity (tetrazolium hydroxide [XTT]), and total protein synthesis rate (sulforhodamine B [SRB]) at concentrations between 6.25 and 100 µM. Note the non-toxicity of PEG 300 (an antifreeze), PG, and MEG (solvents); mild toxicity of SLES (an anionic surfactant) and LE-2 a nonionic surfactant; and the severe toxicity of TN-20, LN-10, and PE-61 (nonionic surfactants). The data on membrane integrity (LDHe) are presented on the right side of the Y-axis, and range from -20% to 120%, which is the toxicity of 1% Triton-X 100 (control).

• 

  Fig. 3 Comparison of toxicity with respect to membrane integrity (A), metabolic activity (B), mitochondrial activity (C), and total protein synthesis rate (D). Note that PEG 300 (an antifreeze), PG, and MEG (solvents) exhibited no toxicity even at a high concentration of 100 mM. Three out of 4 nonionic surfactants (PE-61, TN-20, and LN-10) exhibited severe toxicity in a similar dose-dependent manner between 3.125 µM and 100 mM. The toxicity graph derived from the concentrations of PE-61, TN-20, and LN-10 has a point of inflection at 25 µM. The slope increases slowly up to 25 µM and decreases rapidly thereafter.

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