Evaluation of antidepressant effects of zoledronate in rats

Abstract

Depression is often associated with low bone mineral density. It has been reported that antidepressants, particularly in elderly people, are a cause of low bone strength and fractures. Also it has been found that the antidepressants targeting the serotonin system are harmful for bone health and induce osteoporosis. A relationship between depression and osteoporosis has become more evident over the years, as reduced bone mineral density has been noticed in both depressed women and men. Aged men are more susceptible to the effects of depression on BMD than older women. It has also been observed from different studies that depressed men have lower bone mineral density than non-depressed men. Studies on animals have also indicated that depression may predispose to osteoporosis. Recent long-term studies have also shown that women with menopausal status are at higher risk of depression and osteoporosis. The positive effects of bisphosphonates, including improvement in anxiety or depression, is an area of research in the recent years.The application of bisphosphonates, especially risedronate, ibandronate and etidronate in the treatment of depression along with osteoporosis is limited and no studies have been done using zoledronate. Objective: To evaluate the anti-depressant effect of zoledronate in albino rats. Materials and Methods: After obtaining approval from Institutional Animal Ethics Committee, 18 albino rats weighing 150-250 grams were taken and divided into 3 groups of 6 rats each. Group A (Control): Distilled water 10 ml/kg oral; Group B (Standard) Fluoxetine 20 mg/kg oral for 1 week and Group C (Test) -Zoledronate 0.45 mg/kg oral for 1 week. Anti-depressant effect was assessed after 1 week by performing forced swim test and tail suspension test. Data was analysed using one way ANOVA. p value less than 0.05 was considered significant. Results: Zoledronate (0.45 mg/kg) has shown significant reduction in duration of immobility in both forced swim test (p < 0.05) and tail suspension test (p < 0.05) when compared to control. Conclusion: Results suggest that zoledronate at dose of 0.45 mg/kg has significant anti-depressant effect.