Evaluation of hydroquinone target organ toxicity against liver (BRL3A) and dermal (A375p) cell lines

To assess the target organ toxicity of hydroquinone, liver (BRL3A) and dermal (A375p) derived cell lines were used. The cells viability was assessed by the use of MTT assay. There was significant reduction of cell viabilities of both the cells by hydroquinone standard concentrations. The reduction in cell viability was more pronounced in A375p (dermal) cell line with at least 50% reduction at all concentrations tested. While in BRL3A (liver) cell line, the reduction in cell viability by hydroquinone standard was slightly lower than in A375p cell line. This is a suggestive of hydroquinone specific toxicity to skin cells and to melanocytes, where it exerts its main function on tyrosinase and melanin synthesis. In addition, the possible involvement of reactive oxygen species (ROS) generation in the toxicity process was evaluated using the NBT reduction assay. This is based on the ability of treated cells to stimulate NBT reduction due to the generation of reactive oxygen species. There was significant NBT reduction on treated liver (BRL3A) cells, however the dermal (A375p) cells showed no significant levels of NBT reduction even with positive control suggesting adaptive response in those cells.