Beneficial effects of β-Ecdysone on the joint, epiphyseal cartilage tissue and trabecular bone in ovariectomized rats

Abstract 

Ecdysteroids are steroids found in invertebrates and plants. In mammals they have protein anabolic effects. We have recently published antiosteoporotic effects of Tinospora cordifolia (TC) extract and the search for the possible active ingredients yielded the presence of β-Ecdysone (Ecd). Therefore, we investigated the effects of pure Ecd in ovariectomized rats on morphological changes in joint, epiphyseal cartilage and trabecular tissue. Following ovariectomy rats were fed for 1 month with Ecd containing food at a dose of 52.8mg/day/animal. Positive and negative control animals received 17-β Estradiol (E₂, 132μg/day/animal) and soy free (sf) food respectively. At sacrifice, specimens consisting of upper tibiae-lower femurs and knee joint were harvested and processed for histomorphometry. The parameters measured included thickness of the joint cartilage, thickness of the whole epiphyseal growth plate and its three zones. Furthermore, the percentage of trabecular bone in the metaphysis region of tibiae was quantified. Ecd and E₂ induced a significant increase in the thickness of joint cartilage. The whole epiphyseal growth plate and its proliferative and hypertrophic zones were also increased by Ecd whereas E₂ reduced their size. The percentage of trabecular area in the metaphysis of tibia was significantly increased in Ecd and E₂ treated animals. Results provide a plausible explanation for the antiosteoporotic effects of TC. Hence, TC as well as other Ecd producing plants or pure Ecd may be of value in the prevention and treatment of osteoporosis and osteoarthritis which is of increasing importance due to aging and obesity among individuals.

Keywords: β-Ecdysone, Ovariectomy, Rat, Joint, Epiphysis, Trabeculae