Fucoxanthin alleviates glucocorticoid-induced osteoblast apoptosis by activating nuclear factor erythroid-2-related factor 2

Xie Ting; Liu Tingting; Zeng Xuehui; Li Yamin; Zhou Panghu; Yi Nianhua

doi:10.12307/2024.416

Abstract：BACKGROUND:Osteoporosis has a high incidence,leading to fracture and other complications.However,existing drugs have great side effects and are difficult to meet the clinical application. OBJECTIVE:To explore the effect and potential mechanism of fucoxanthin on osteoporosis induced by glucocorticoid. METHODS:Primary rat osteoblasts were inoculated in 6-well plates.When the cell fusion reached 80%,the cells were divided into four groups:the control group was cultured alone for 24 hours,the glucocorticoid group was intervened with dexamethasone for 24 hours,the fucoxanthin group was intervened with fucoxanthin for 24 hours,and the glucocorticoid + fucoxanthin group was intervened with dexamethasone and fucoxanthin at the same time for 24 hours.After intervention,cell proliferation,apoptosis,intracellular reactive oxygen species level,and protein expression of apoptosis-related proteins,bone formation-related proteins,and nuclear factor erythroid-2-related factor 2 were detected. RESULTS AND CONCLUSION:Cell counting kit-8 results showed that the cell viability was decreased in the glucocorticoid group compared with the control group(P＜0.05)but increased in the glucocorticoid+fucoxanthin group compared with the glucocorticoid group(P＜0.05).JC-1 mitochondrial membrane potential staining and flow cytometry assay showed that the percentage of apoptosis increased in the glucocorticoid group compared with the control group(P＜0.05)but decreased in the glucocorticoid+fucoxanthin group compared with the glucocorticoid group(P＜0.05).Western blot assay showed that compared with the control group,the protein expression of BAX and cleaved poly(ADP-ribose)polymerase was elevated in the glucocorticoid group(P＜0.05),and the protein expression of BCL2,type Ⅰ collagen α1 peptide chain,alkaline phosphatase,osteocalcin,and RUNX2 was decreased in the glucocorticoid group(P＜0.05).Compared with the glucocorticoid group,the protein expression of BAX and cleaved poly(ADP-ribose)polymerase was decreased(P＜0.05),and the protein expression of BCL2,type Ⅰ collagen α1 peptide chain,alkaline phosphatase,osteocalcin,and RUNX2 was elevated(P＜0.05)in the glucocorticoid+fucoxanthin group.Fluorescent probe assay showed an increase in reactive oxygen species level in the glucocorticoid group compared with the control group(P＜0.05)and a decrease in reactive oxygen species level in the glucocorticoid+fucoxanthin group compared with the glucocorticoid group(P＜0.05).Immunofluorescence staining and western blot assay showed that the protein expression of nuclear factor erythroid-2-related factor 2 in the glucocorticoid group was decreased compared with that in the control group(P＜0.05);and the protein expression of nuclear factor erythroid-2-related factor 2 in the glucocorticoid+fucoxanthin group was elevated compared with that in the glucocorticoid group(P＜0.05).To conclude,fucoxanthin can improve glucocorticoid-induced osteoblast apoptosis and the expression of bone formation-related molecules by activating nuclear factor erythroid-2-related factor 2.