Effect of tetracycline on the cell viability and the expression of MMPs in human keratinocytes treated with L. laeta venom.

HaCaT cell cultures were incubated with 100 μg/mL of L. laeta venom (V) or control medium (C) in the presence or absence of tetracycline (T). After 72 hours of treatment, cell viability was analyzed by MTT assay (A) and cell supernatants were analyzed by zymography (B), western blotting (C) and Luminex assay (tetracycline: 150 μg/mL) (D). Results are representative of three independent experiments and are expressed as the mean of triplicates ± standard deviation. Significant differences (*) P<0.05; (**) P<0.01 and (***) P<0.001 from control or (#) P<0.05; (##) P<0.01 and (###) P<0.001 from venom treated cells.