| The effects of bisphosphonates were evaluated on osteoblastic viability and expression of IL-6, TGF-beta1, and RANKL. Primary rat osteoblasts were cultured in media containing increasing concentrations of two different bisphosphonates. Alendronate was added to half of the cells at 10-6 M, 10-5M, 10-4M, and 10-3M concentrations. Zoledronate was added to the other half of the cells at 3muM, 10muM, 60muM, and 100muM concentrations. Control groups received culture media containing no medication. Supernatants were harvested after 24, 48, and 72 hours and analyzed with enzyme-linked immuno-absorbent assays (ELISAs) to measure the expression of IL-6, TGF-beta1, and RANKL. Live and necrotic cell numbers at each time point were assessed with trypan blue exclusion assays. Both alendronate and zoledronate treatment groups showed significant decreases in viability as concentration increased. ELISA analysis revealed significant increases in TGF-beta1 concentration in treatment groups, when calculated per live cell. Additionally, zoledronate control groups reflected a temporary increase in RANKL, which did not occur in treatment groups with either drug. ELISA analysis revealed no significant differences in IL-6 production between any of the groups. |
