[Therapeutic effect of aqueous-extract from a traditional Chinese medical herb Drynaria fortunei on rat experimental model of alveolar bone resorption]

Abstract

Objective: To establish a rat model of experimental alveolar bone resorption and understand the therapeutic effect of a traditional Chinese medical herb Drynaria fortunei (DFS) on the rats suffering from alveolar bone resorption.

Method: A SD rat model with experimental alveolar bone resorption was established by using injection with E. coli Lipopolysaccharide (E-LPS) in local tissue of the animals. A DFS preparation (DFS aqueous-extract) was extracted with distilled water. The modeled rats were administrated by perfusion with DFS aqueous-extract at a dosage of 15 g crude drug/kg once a day for 10, 20 and 30 d, respectively. The effects of DFS aqueous extract on experimental alveolar bone resorption were estimated by detections of serum alkali phosphate (ALP) activity, Ca2+ and osteocalcin (OC) levels, and TRAP stained osteoclast count, bone mineral density (BMD) measurement and HE stained histopathological examination of the tooth-periodontal samples.

Result: In comparison with the controls, BMD values of the alveolar bones at experimental tooth sites of the tested rats with DFS aqueous-extract for 10 d administration were obviously increased (P < 0.05). In the tooth-periodontal samples from the rats for 10 d administration, disappearance of the osteoclast, decrease of Howship's lacuna numbers and formation of new non-calcified bone-like matrix attached by osteoblasts in alveolar bone at the root furcation from most of the samples occurred. Similar examining results in the tooth-periodontal samples from the rats for 20 and 30 d administrations were obtained, respectively. However, no statistically significant differences of the serum ALP activity, Ca2+ and OC levels among the tested rats for 10-30 d treatment and the controls (P > 0.05) were found.

Conclusion: The DFS aqueous extract has exact therapeutic effect on rat experimental alveolar bone resorption through suppressing bone resorption and promoting bone regeneration. Serum ALP activity, Ca2+ and osteocalcin (OC) levels can not be used as the effective index for examining alveolar bone resorption and regeneration in animal models.