Study the impact of astaxanthin on developing of genomic instability in human peripheral blood lymphocytes irradiated in vitro on G2 phase of cell cycle.

OBJECTIVE

To identify the possibility of modification by astaxanthin the level of genome damages induced by gamma quanta in the culture of human peripheral blood lymphocytes exposed in vitro on postsynthetic (G2) phase of the first mitotic cycle.

MATERIALS AND METHODS

Peripheral blood lymphocytes from four apparently healthy volunteers 35-51 years old were cultivated using modified micromethod. To obtain genomic damages in G2 phase of the first mitotic cycle the part of cultures was irradiated by γ quanta in dose 1.0 Gy through 46 hours of cultivation. Astaxanthin in final con centration 20 μg/ml was exposed to lymphocytes' cultures before the irradiation. Cytogenetic analysis the uniform ly stained slides of metaphase chromosomes was carried out to determine the frequencies of chromosome and chro matid types of aberrations. Using the method of individual cells electrophoresis (Comet assay) the relative level of DNA damages (Tail Moment index) and the frequency of apoptotic cells with high level of DNA fragmentation were evaluated.

RESULTS

Mean group frequencies of chromosome aberrations after gamma irradiation of lymphocytes in vitro exceed ed those without radiation exposure and were 72.35 ± 1.17 and 2.46 ± 0.30 per 100 metaphases, respectively (p < 0.001), mainly due to chromatid type of aberrations (58.32 ± 1.29 per 100 metaphases). Adding of astaxanthin into culture medium before the irradiation did not result in changes as in the frequency of chromosomal damages (71.54 ± 1.34 per 100 metaphases) as in the spectrum of aberrations - also prevailed chromatid type of aberrations (58.47 ± 1.47 per 100 metaphases). The increase of Tail Moment index after radiation exposure (from 3.84 ± 0.36 to 12.06 ± 1.88, respectively, p < 0.001) and lack of significant impact of astaxanthin on this index in the irradiated lym phocytes (8.96 ± 2.39, p > 0.05) was established, ie astaxanthin didn't change the relative level of radiation induced DNA damages. Also apoptogenic effect of astaxanthin was not found: frequency of apoptotic cells were (2.25 ± 1.49) % in cultures of intact lymphocytes, (2.08 ± 1.54) % in irradiated cultures and (1.78 ± 1.25) % under joint action of gamma radiation and astaxanthin (p > 0.05).

CONCLUSIONS

Noimpactofastaxanthinongenomicinstabilityinducedbygammairradiation invitroinculturesof human peripheral blood lymphocytes on postsynthetic (G2) phase of first mitotic cycle had been established.