Figure 8. The effects of carnosine on HEWL-induced membrane damage (LDH release into the medium) in SH-SY5Y cells.

The cell viability upon exposure to HEWL sample was measured by the LDH release assay. SH-SY5Y cells were incubated with 50 mM carnosine alone (the negative control) and HEWL samples without or with various concentrations of carnosine (10, 20, 30, 40, and 50 mM) for 6, 12, and 24 hr at 37°C in a humidified 5% (v/v) CO₂/air environment. The percentage of cytotoxicity was evaluated as a ratio of the quantity of LDH released in each sample divided by the total LDH released by the sample of cells treated with lysis buffer. Quantity of released LDH is estimated by the activity of lactate dehydrogenase in the suspension aliquot from the 96-well plates after 30 min incubation with the appropriate substrate solution. Measurements of the means ± S.D. of at least 8 determinations for each sample were obtained at 490 nm.