Retinoic acid

Retinoic acid was procured from Tokyo chemical industry, Japan. Plasmid DNA and hyaluronic acid were obtained from RL Chem Industries, India. HCT-15 human cell line was purchased from National Centre for Cell Sciences, Pune, India. All other reagents were of analytical grade and used without further purification.

Test compounds used in this study are listed in Table 1. These tested compounds are known to be teratogens inducing cleft palate in mammals and have been classified into various categories as a result of being tested in zebrafish experiments or chemical safety assays (Hillegass et al., 2008 (link); Selderslaghs et al., 2009 (link); Ito and Handa, 2012 (link); Lee et al., 2012 (link); Teixido et al., 2013 (link); Yamashita et al., 2014 (link); Inoue et al., 2016 (link); Martinez et al., 2018 (link); Cassar et al., 2019 (link)). The test compounds and exposure concentrations were determined based on Liu et al., 2020 (link). The exposure concentrations were as follows: hydroxyurea (1 mM, Sigma-Aldrich), valproic acid (7.5–30 μM, Wako), salicylic acid (100–400 μM, Wako), boric acid (1 mM, Wako), and caffeine (0.5–2 mM, Wako), which were diluted from stock solutions prepared with distilled water (Life Technologies), and imatinib (250 μM, Tokyo Chemical Industry), retinoic acid (10–50 nM, Tokyo Chemical Industry), thalidomide (400 μM, Tocris Bioscience), methotrexate (50–200 μM, Wako), warfarin (15–60 μM, Wako), phenytoin (1 mM, Wako), dexamethasone (1 mM, Wako), 5-fluorouracil (1 mM, Wako), and isoniazid (1 mM, LKT Laboratories), which were diluted from stock solutions prepared with dimethyl sulfoxide (DMSO, Wako).