phenanthrenes and Osteoporosis

Triptolide (TPL), the active component of Tripterygium wilfordii Hook F (Twhf) has been used to treat cancer and bone loss conditions for over two hundred years in traditional Chinese medicine (TCM). In this paper, we reviewed the specific molecular mechanisms in the treatment of cancer, bone loss and cardiovascular disease. In addition, we analyze the toxicity of TPL and collect some optimized derivatives extracted from TPL. Although positive results were obtained in most cell culture and animal studies, further studies are needed to substantiate the beneficial effects of TPL.

Topics: Animals; Anti-Inflammatory Agents; Apoptosis; Arthritis, Rheumatoid; Autophagy; Cardiovascular Diseases; Diterpenes; Epoxy Compounds; Humans; Medicine, Chinese Traditional; Neoplasms; Osteoporosis; Phenanthrenes; Plant Extracts; Signal Transduction; Tripterygium

Previous studies have showed that triptolide have a critical role in inhibiting osteoclast formation, bone resorption and attenuating regional osteoporosis. However, the protective role of triptolide on age-related bone loss has not been investigated. In the study, we assessed the effect of triptolide supplementation on bone microstructure and bone remolding in old male rat lumbars.. Fifty-two 22-month-old male Sprague-Dawley rats were randomly assigned to either triptolide treatment group or control group. Triptolide (15 μg/kg/d) or normal saline was administered to the rats of assigned group for 8 weeks. Lumbar bone mineral density (BMD) and bone microstructure were analyzed by micro-CT. Fluorochrome labeling of the bones was performed to measure the mineral apposition rate (MAR) and bone formation rate (BFR). Osteoclast number was also measured by TRAP staining. Plasma level of osteocalcin and tartrate-resistant acid phosphatase 5b (Tracp 5b) was also analyzed.. Micro-CT results revealed that triptolide-treated rats had significant higher BMD, bone volume over total volume (BV/TV), trabecular thickness (Tb.Th), bone trabecular number (Tb.N), and lower trabecular separation (Tb.Sp) compared to the control group. Although fluorochrome labeling result showed no significant difference in MAR and BFR between the groups, triptolide decreased osteoclast number in vivo. In addition, a significant higher level of plasma Tracp 5b was observed in the triptolide-treated rats. Furthermore, triptolide also reduced the expression of receptor for activation of NF-κB ligand (RANKL) and increased osteoprotegerin (OPG) expression in the lumbars.. These results suggested that triptolide had a protective effect on age-related bone loss at least in part by reducing osteoclast number in elder rats. Therefore, triptolide might be a feasible therapeutic approach for senile osteoporosis.

Topics: Animals; Bone Resorption; Diterpenes; Epoxy Compounds; Male; Osteoclasts; Osteoporosis; Phenanthrenes; Rats; Rats, Sprague-Dawley

Most bone-related diseases are characterized by excessive bone resorption by osteoclasts. Receptor activator of nuclear factor-kappa B (NF-κB) ligand (RANKL) has emerged as a major mediator of bone resorption, commonly associated with cancer and chronic inflammatory diseases. Thus inhibitors of RANKL signaling have a potential in preventing bone loss. In the present study, we investigated the ability of triptolide, a diterpenoid isolated from Thunder of God Vine, to inhibit signaling by receptor activator of NF-κB (RANK) and its ligand (RANKL) and to modulate osteoclastogenesis induced by RANKL and human cancer cells. We found that triptolide suppressed RANKL-induced differentiation of precursor cells to osteoclasts, and also inhibited osteoclast formation induced by human breast tumor cells (MDA-MB-231), multiple myeloma cells (U266) and prostate tumor cells (PC-3). Triptolide inhibited RANKL-induced NF-κB activation in osteoclast precursor cells by inhibiting IκBα kinase activation, IκBα phosphorylation, and IκBα degradation. Our results suggest that triptolide effectively inhibits RANKL-induced NF-κB activation and RANKL- and tumor cell-induced osteoclastogenesis. This warrants further study of triptolide as a potential therapy for osteoporosis and cancer-associated bone loss.

Topics: Animals; Bone Resorption; Cell Differentiation; Cell Line, Tumor; Diterpenes; Epoxy Compounds; Humans; Mice; Neoplasms; Osteoclasts; Osteoporosis; Phenanthrenes; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Signal Transduction

To observe the prevention and therapeutic effects of tanshitone (TAN) on retinoic acid induced osteoporosis in mice.. The mice osteoporosis was induced by given retinoic acid intragastrically for two weeks. The histomorphological features of bone were observed and biochemical indexes in serum (Ca, P, ALP, TRAP, E2, BGP) were determined after the mice were given TAN at the dose of 40, 80, 160 mg x kg(-1) respectly.. Tanshinone can induce high conversion of osteoporosis. The levels of P, ALP, TRAP and BGP in the TAN groups were lower than the model group, while the E2 level was higher than the model group.. Tanshitone can prevent the loss bone in the experimental mice. The mechanism may be that it improves the level of estrogenic hormone and inhibits the high bone turnover.

Topics: Abietanes; Alkaline Phosphatase; Animals; Bone Density; Disease Models, Animal; Drugs, Chinese Herbal; Female; Humans; Male; Mice; Osteoporosis; Phenanthrenes; Tretinoin