IMPACT OF ASTAXANTHIN ON MANIFESTATIONS OF THE DIRECT AND RESCUE TUMOR-INDUCED BYSTANDER EFFECT.

Objective: to investigate the reciprocal impact on the genome of malignant and normal human peripheral bloodlymphocytes under their co-culture and the possibility to modify the effects by astaxanthin.

Methods: Separate and joint/separate culturing of peripheral blood lymphocytes (PBL) of the chronic lymphocyticleukemia (CLL) patients (n = 6) and conditionally healthy individuals (n = 6), Comet assay method, fluorescencemicroscopy with automated software for the analysis of results, statistical methods.

Results: Both direct and rescue tumour-induced bystander effects were observed under the joint/separate culturing of blood lymphocytes of conditionally healthy individuals (the bystander cells) and blood cells from CLL patients(the inducer cells). The direct effect was characterized by the high level of comets corresponding to the S-phasecells and increased apoptotic activity in the bystander cell cultures. The rescue effect in the culture of inducer cellswas expressed by the increased frequency of cells retained in S-phase, decreased proportion of cells with a high levelof DNA damage and decreased amount of cells in apoptotic stage. Level of both S-phase cells and apoptotic cells inthe cultures of bystander cells significantly decreased under the impact of astaxanthin (p < 0.05). Effect of astaxanthin on the inducer cells was the opposite, namely an increased frequency of S-phase cells and increased apoptotic activity in cultures (p < 0.05) was observed.

Conclusions: Possible modification of manifestations of both direct and rescue tumor-induced bystander effects bythe astaxanthin was established.