166-171Triclosan, a broad spectrum antibiotic is
currently being evaluated for its anti-cancer property. Though several solvents
are available to dissolve lipophilic (hydrophobic) drugs, solubility and
toxicity aspects pose a challenge, when combined with the cell culture medium.
In this paper, we present a simple approach based on physico-chemical and
biologic criteria to choose a suitable solubilizing agent to study the
anti-proliferative property of triclosan in breast cancer cell line MCF-7.
Triclosan was dissolved in five different solvents viz. DMSO, absolute ethanol,
1 N NaOH, 55% polyethylene glycol + 45% ethanol mixture
(PEM) and acetone and diluted with the culture medium
(1 mg/ml). Although triclosan dissolved completely in all five solvents, on
dilution with culture medium, turbidity was observed in DMSO, 1 N NaOH and
ethanol. Cell viability was 95.23% in 10 ml of acetone, when compared with 49.45% at the same volume of PEM.
This non-toxic nature of acetone was supported by DNA fragmentation analysis
and phase contrast microscopy. A significant decrease in cancer cell
proliferation at 100 mg/ml of
acetone-solubilized triclosan, compared with 100 mg/ml of PEM-solubilized triclosan (p<0.05) indicated stronger
anti-proliferative effect and greater drug-sensitivity of triclosan when solubilized
in acetone. Results showed that acetone-solubilized triclosan was suitable for anti-cancer
investigations in cultured MCF-7 cells