Selenium-phycocyanin from selenium-enriched cultures of: Nostoc sp. isolated from rice field prevents human kidney cells from paraquat-induced damage

Abstract

Selenium-containing phycocyanin (Se-PC) was purified from Se-enriched cultures of a nitrogen-fixing cyanobacterium (Nostoc sp.) using fast protein liquid chromatography. Ammonium sulfate precipitation, DEAE-Sepharose ion-exchange chromatography, and Sephacry S-300 size exclusion chromatography were employed in the process of protein purification. The purity ratio and the separation factor of the purified Se-PC were found to be 5.97 and 14.73, respectively. The Se content in the Se-PC was 550 μg g-1 protein as determined by ICP-AES analysis. Interestingly, we also found that, Se-PC could effectively suppress the paraquat (PQ)-induced cell death and morphological changes, reverse PQ-induced DNA fragmentation and nuclear condensation, and block PQ-induced cell apoptosis through inhibition of superoxide overproduction in human kidney HK-2 cells. The results indicate that Se-PC is a promising selenium species for the protection of renal cells from paraquat-induced damage.