1. Xinjiang sambucus sibirica Nakai bark extract promotes fracture healing
Chinese Journal of Tissue Engineering Research 2020;24(20):3122-3129
BACKGROUND: Studies have found that Sambucus sibirica Nakai can promote osteoblast division, proliferation, and secretion of alkaline phosphatase to accelerate bone matrix calcification, promote new bone formation, and promote the absorption of necrotic bone. OBJECTIVE: To observe the effects of two extracts of Xinjiang Sambucus sibirica Nakai bark in promoting fracture healing in rats. METHODS: A total of 108 male Sprague-Dawley rats, 3 months old, were randomly divided into sham-operated group, model group, Zhong Hua Die Da Wan group (0.54 g/kg, negative control group), high-, middle- and low-dose ethanol extract groups (0.314, 0.157, 0.078 g/kg), high-, middle, and low-dose water extract groups (0.340, 0.170, 0.085 g/kg). Except for the sham-operated group, the middle segment of the femoral shaft was cut off to make a model of open femoral fracture. In the sham-operated group, only the femoral shaft was exposed and no osteotomy was performed. Intragastric administration began at 1 day after modeling and continued for 6 weeks (1 time/day). At 2, 4, 6 weeks after modeling, the effects of two extracts of Sambucus sibirica Nakai bark on serum-related biochemical indicators, X-ray imaging, biomechanical indicators and hematoxylin-eosin staining were observed. RESULTS AND CONCLUSION: (1) Serum biochemical indicators: The serum calcium level of the high-dose ethanol extract group in each phase was lower than that of the sham-operated group and the model group, indicating that a faster osteogenesis in the high-dose ethanol extract group, followed by middle-dose ethanol extract group, low-dose ethanol extract group, and high-dose water extract group. The serum phosphorus level of ethanol extract groups was higher than that of sham-operated group, model group, and Zhong Hua Die Da Wan group; the serum alkaline phosphatase level of high-dose ethanol extract group at each stage was significantly higher than the other groups, indicating that a stronger osteoblast activity in the high-dose ethanol extract group, followed by the high-dose water extract group. (2) X-ray film: Fracture healing was significant in the high-dose ethanol extract group, fair in the Zhong Hua Die Da Wan group, high-dose water extract, middle-dose water extract group, middle-dose ethanol extract group, and poor in the low-dose ethanol extract group and low-dose water extract group. (3) Three-point bending test: At 6 weeks, the maximum load and maximum deflection of the femurs of the two extract groups were higher than those in the model group. The maximum load and maximum deflection of the femurs increased significantly in the high-dose ethanol extract group followed by the high-dose water extract group, middle-dose water extract group and middle-dose ethanol extract group. (4) Hematoxylin-eosin staining: Fibrous epiphysis gradually formed in the fracture area, and the bone marrow cavity was communicated. Bone healing was better in the high-dose ethanol extract and high-dose water extract groups than in the other groups. To conclude, these two extracts of Xinjiang Sambucus sibirica Nakai bark are capable of improving fracture healing. Moreover, different extraction methods and dosages of Sambucus sibirica Nakai bark demonstrate various effects on fracture healing. Compared with water extracts, ethanol extracts are better to promote fracture healing, and high-dose extracts have better effects than middle- and low-dose extracts.