THE ANTI-OSTEOPOROTIC ACTIVITY OF AMINE-CARBOXYBORANES IN RODENTS

Amine-carboxyboranes have been shown to prevent osteoporosis and loss of bone mass in rodents. In vitro studies using CF1 mouse pup calvaria and rat UMR-I06 osteosarcoma cells showed that amine-carboxyborane de rivatives reduced significantly the loss of intracellular calcium into the growth medium from 10(-4) to 10(-8) M over 48 hours. Amine-carbox yborane derivatives were more effective than calcitonin or simple boro n salts. Calcium incorporation into these cells and proline incorporat ion into collagen was accelerated in the presence of amine carboxybora nes. The amine-carboxyborane derivatives effectively inhibited lysosom al and proteolytic enzymes as well as activities of serine elastase, p rostaglandin cyclooxygenase, and 5'-lipoxygenase in mouse macrophages, human PMNs, leukocytes and Be Sal cells. IC50, values were in the ran ge of 10(-6) M. In lactating ovariectomized female rats after administ ered amine-carboxyboranes for 14 days at 8 mg/kg/day orally, the femur and humerus showed increased volume, weight, density and ash weight. Serum calcium levels were elevated significantly with minimum reductio ns on serum inorganic phosphate levels. Femur calcium levels were elev ated after treatment with amine-carboxyborane derivatives, but not wit h etidronate. Humerus total lipids after 14 days were slightly elevate d probably due to increased levels of triglycerides and phospholipids.