ALP	Alkaline phosphatase
BAH	Bovine skin gelatin hydrolysate by alcalase
BNH	Bovine skin gelatin hydrolysate by neutrase
BPH	Bovine skin gelatin hydrolysate by papain
CCK-8	Cell counting kit-8
DH	Degree of hydrolysis
DKK-1	Dickkopf-1
E2	17β-estradiol
EDTA	Ethylenediamine tetra-acetic acid
EP	Etoposide
ER-FBS	Estrogen-removed fetal bovine serum
FBS	Fetal bovine serum
hFOB 1.19 cells	Human fetal osteoblastic cells
PAH	Porcine skin gelatin hydrolysate by alcalcase
PBS	Phosphate-buffered saline
PNH	Porcine skin gelatin hydrolysate by neytrase
PPH	Provine skin gelatin hydrolysate by papain
TAH	Tilapia skin gelatin hydrolysate by alcalase
TNH	Tilapia skin gelatin hydrolysate by neutrase
TPH	Tilapia skin gelatin hydrolysate by papain