[Screening on antiosteoporotic active parts of dipsacus radix based on zebrafish model]

Prednisolone-induced osteoporosis model using zebrafish was used to screen the antiosteoporotic active parts of Dipsacus Radix, in order to investigate the applicability and rationality of the zebrafish model of osteoporosis.

Zebrafish larvae at 5 days post fertilization (dpf) were exposed with 25 micromol/L prednisolone and 0.5% DMSO for 48 h, then except one group of 25 micromol/L prednisolone, other groups of 25 micromol/L prednisolone were treated with a range of concentration (0.025, 0.25, 2.5, 25 microg crude drug/mL) of extract of Dipsacus Radix and its different concentration ethanol elution parts of macroporous resin with 25 micromol/L prednisolone. All groups were incubated in 24-well plates (28.5 degrees C) until 10 dpf. Zebrafish skeleton at 10 dpf were anesthetized and fixed for staining with alizarin red. Quantitative analysis of the stained area was performed by microscopic inspection and digital imaging methods to reflect the amount of zebrafish head skeleton mineralization.

The results indicated that head skeleton mineral area and integrated optical density (IOD) of 25 micromol/L prednisolone model group were significantly decreased when compared with vehicle control group, and the extract of Dipsacus Radix and its 30%, 50%, 70% and 90% ethanol elution parts of macroporous resin rescued the further bone loss of zebrafish induced by prednisolone when compared with the model group. HPLC analysis indicated that components of 30%, 50%, 70% and 90% ethanol elution parts of macroporous resin containing saponins and nonsaponins components.

Both saponins and nonsaponins can prevent bone loss of zebrafish induced by prednisolone. This novel osteoporosis zebrafish model was successfully used to screen antiosteoporotic active parts of Dipsacus Radix, which had advantages of simple, high efficiency and easy to perform.