Cytotoxic evaluation of certain insect growth regulators and insect sex pheromones in cho-k1 cells

The cytotoxic effects of Diflubeizuron, pyriproxifen as insect growth regulators, ZZ/ZE-7,11-hexadecadienyl acetate, Z-9- hexadecenal and Z-11-hexadecenal as insect sex pheromones were evaluated in vitro using Chinese hamster ovary [CHO-K1] cells. Total cellular protein [TCP] content and methyl tetrazolium [MTT] assays were carried out using serum free medium and medium supplemented with fetal calf serum [FCS, 10%], bovine serum albumin [BSA, 1%] and/or metabolic activation system [S9-mix]. All the tested compounds displayed cytotoxic effects that rise with time exposure. TCP assay exhibited higher sensitivity than MTT assay with all the tested compounds. In presence of the added extracellular proteins and/or metabolic activation system [S9-mix], the cytotoxic effects significantly decreased which indicate that the tested agents may be binding non-specifically with protein and extensive metabolized to less toxic metabolites

Lack of initiation activity of 4-oxo-2-hexenal, a peroxidation product generated from omega-3 polyunsaturated fatty acids, in an in vivo five-week liver assay.

Peroxidation products formed from polyunsaturated lipids have DNA damaging potential. 4-oxo-2-hexenal (4-OHE), generated by the oxidation of omega-3 fatty acids, has been demonstrated to be mutagenic in vitro as assessed in the Ames test. To examine the carcinogenic risk of 4-OHE in vivo, initiation activity was investigated in a five-week liver assay, established to be effective for screening of carcinogenic potential of mutagens. Seven-week-old male F344 rats underwent two-thirds partial hepatectomy (PH) and were administered 4-OHE intragastrically at doses of 128, 80, 64, 40, 32, 20, or 0 mg/kg body weight (b.w.) at 18 hours thereafter, then being fed on diet containing 0.015% 2-acetylaminofluorene from weeks 2 to 4. All rats were given with 0.8 ml/kg b.w. CCl4 at week 3. At week 5, all survivors were sacrificed and initiation activity was assessed with reference to induction of glutathione S-transferase placental form (GST-P) positive foci in the liver. Mortality was significantly increased to 72.7% in the 128 mg/kg b.w. dose group compared with 0.9% in the control group. However, the average number of GST-P positive foci in the "128" dose group was 3.26-/+1.66 foci/cm2, not significantly different from the control value (2.78?1.33). Areas of GST-P positive foci were also similar (1.11-/+0.5 and 1.53-/+1.33 mm2/cm2 in "128" and the control groups, respectively). These results showed 4-OHE to have no significant initiation activity in.