2023, Vol. 27 ›› Issue (11): 1677-1682

Proliferation and differentiation of osteoblasts promoted by the two extracts of Sambucus adnata Wall.

Zheng Meimei1, Zheng Jianbin1, Jiang Zixian1, Jia Zhaoyu1, Wang Tao2, Wang Wenjing1     

Abstract: BACKGROUND: Osteoblasts and osteoclasts play an important role in bone remodeling through the release of regulatory factors to remain the bone homeostasis. When the balance between functions and activities of the two types of cells is disturbed, bone diseases such as osteoporosis and osteoarthritis will occur. Sambucus adnata Wall. is commonly used by the ethnic Yi people to treat injuries caused by falls and fractures. Our previous studies have found that the water extract (SAW-A) and dichloromethane extract (SAW-B) of Sambucus adnata Wall. can promote fracture healing and improve osteoporosis in the active parts of fractures. However, their effects on osteoblast proliferation and differentiation in the active parts are still unclear.
OBJECTIVE: To investigate the biological effects of SAW-A and SAW-B extracts from Sambucus adnata Wall. on the proliferation and differentiation of osteoblasts.
METHODS: Osteoblasts were extracted from the skull of newborn Sprague-Dawley rats by collagenase digestion, and cell counting kit-8 was used to detect the cytotoxicity of SAW-A and SAW-B. The proliferation activity of osteoblasts was detected by cell counting kit-8 at 24, 48, and 72 hours after extract intervention, to investigate the effects of 312.5 mg/L SAW-A and 156.15 mg/L SAW-B on osteoblast proliferation. Flow cytometry was used to detect the effect of SAW-A and SAW-B on cell activity at 6 days of intervention. The proliferation and differentiation of osteoblasts after SAW-A and SAW-B intervention were detected by alkaline phosphatase staining and alizarin red staining. Real-time fluorescence quantitative PCR assay was performed to detect the relative expression of osteogenesis-related genes RUNX2, bone sialoprotein, osteocalcin and type I collagen A1.
RESULTS AND CONCLUSION: SAW-A and SAW-B could significantly improve the proliferation of osteoblasts at 48 and 72 hours after intervention, and SAW-B was stronger than SAW-A. Flow cytometry results showed that SAW-A and SAW-B inhibited apoptosis in osteoblasts after 6 days of intervention. The results of alkaline phosphatase and alizarin red staining showed that SAW-A and SAW-B could promote osteoblast mineralization. The relative expression levels of RUNX2, bone sialoprotein, osteocalcin and type I collagen A1 increased, and SAW-B showed a better effect on the expression of bone sialoprotein and type I collagen A1 than SAW-A. To conclude, SAW-A and SAW-B can both promote osteoblast differentiation.
Key words: Sambucus adnata Wall., water extract, dichloromethane extract, osteoblast, osteoblast proliferation, osteoblast differentiation, bone homeostasis, osteoporosis