ABSTRACT
Objective To study the mechanisms of anti-oxidation and anti-aging of Sargassum fusiforme polysaccharides (SFPS). Methods qRT-PCR and Western blotting were utilized to detect the expression of c-Jun-N-terminal kinase 1/2 (JNK1/2) in male mice with different ages and in the old male mice fed with SFPS. The JNK isoforms were specifically distinguished by RT-PCR and the expression levels of each isoform in the liver of mice by ig administration of SFPS or normal saline were measured. Finally, the mechanism of JNK activating Nrf2/ARE signaling pathway was determined by co-immunoprecipitation and ARE-luciferase reporter gene assay. Results The expression levels of JNK1/2 were negatively correlated with aging process. JNK1-β2, JNK2-α1, and JNK2-β2 played important roles in aging process. The mRNA expression level of JNK1-β2, JNK2-α1, and JNK2-β2 were significantly decreased in mice aging process, and the protein expression levels of JNK1-β2 (5.4×104) were significantly upregulated by long-term diet with SFPS. The JNK1-β2 (5.4×104) protein interacted with anti-oxidant factor Nrf2, and significantly activated Nrf2/ARE signaling pathway. Conclusion JNK1-β2, JNK2-α1 and JNK2-β2 had negative correlation with aging process, and the expression level of JNK1-β2 (5.4×104) in aged mice were obviously promoted by long-term diet with SFPS. As JNK1-β2 containing C-terminal tail can interact with Nrf2 and activate the NRF2/ARE signaling pathway, therefore, it was suggested that SFPS can improve the overall anti-oxidant capacity and retard aging process by activating of the JNK1-β2/Nrf2/ARE signaling pathway.
ABSTRACT
Objective To study the anti-tumor effects of SFPS against human colon cancer cells.Methods Inhibition of the cell proliferation was measured by MTT assay.SFPS induced apoptosis of lovo and RKO cells was observed by electron microscopy and flow cytometry.The potential of SFPS in inhibiting lovo and RKO cells viability was assessed by MTT assay.Results SFPS significantly exhibited antiproliferative activity which depended on dosage.Morphological examination showed chromosomal condensation, karyotheca margination,cell shrinkage and the presence of apoptosis bodies.The overall effect of SFPS on the cell cycle distribution was examined by flow cytometry.However,it was also found that SFPS arrested the human colon cancer cell line RKO at G0/G1 phase,and the RKO cells at S phase decreased significantly,while no change in cell cycle distribution from SFPS treated lovo cells was observed.Conclusion SFPS may induce the apoptosis of lovo and RKO cells in vitro through anti-tumor proliferation.