Osteoporosis is characterized by reduced bone mass, abnormal bone architecture and increased fracture risk.
Ovariectomy impairs bone mass and metabolism in rats and ovariectomized rats are considered as a suitable model of
postmenopausal osteoporosis.
Mevalonate is required for producing lipoids that are important in osteoclast activity and thus drugs affecting
mevalonate production can prevent bone loss in rodents.
Policosanol is a
cholesterol-lowering drug isolated from
sugar cane wax that inhibits
cholesterol biosynthesis through an indirect regulation of hydroxymethylglutaryl
coenzyme A (
HMG-CoA) reductase activity. The purpose of this study was to determine whether
policosanol could prevent bone loss in the bones of ovariectomized rats by comparing its effects with those induced by
estradiol. Sprague Dawley female rats were randomly distributed in four groups: a
sham-operated group treated with
Tween/H2O vehicle and three groups of ovariectomized rats treated with 17beta-estradiol (30 microg/kg/day) or
policosanol (50 and 200 mg/kg/day), respectively, for 3 months. At treatment completion the rats were sacrificed, their bones removed and variables of
bone resorption and formation were investigated by histomorphometry.
Ovariectomy increased trabecular separation but diminished the number and thickness of trabecules.
Estradiol and
policosanol prevented these effects compared with ovariectomized controls. Both treatments also prevented an increase in the number of osteoclasts and their surface area induced by
ovariectomy.
Estradiol, but not
policosanol, significantly prevented an increase of osteoblast surface area compared with ovariectomized controls. In conclusion,
policosanol prevented bone loss and decreased
bone resorption in ovariectomized rats, suggesting that it should be potentially useful in preventing bone loss in postmenopausal women.