Influence of Palmatine on Bone Metabolism in Ovariectomized Mice and Cytokine Secretion of Osteoblasts

Abstract

Background/aim: Receptor activator of nuclear factor-κB ligand (RANKL) and osteoprotegerin (OPG), regulate the cognate receptor RANK on osteoclast precursor cells. Herein we examined the inhibitory effects of palmatine on bone metabolism using ovariectomized (OVX) mice.

Materials and methods: The first experimentaI set was designed to histologically and biochemically examine mice randomly divided into four groups: sham-operated, OVX, and OVX-palmatine intake groups (1 mg/kg and 10 mg/kg). The second experimental set examined the influence of palmatine on osteoblast-like cells in vitro.

Results: Palmatine caused significant suppression of osteoclast numbers in tissues. In palmatine-treated mice, RANKL and OPG expression decreased. In the culture supernatant of MC3T3-E1 cells, RANKL and OPG levels were significantly reduced by palmatine addition.

Conclusion: Palmatine may attenuate osteoclast differentiation through inhibition of RANKL and OPG expression by osteoblasts. Therefore, palmatine might be a candidate anti-resorptive agent for osteoporosis therapy.

Keywords: Receptor activator of nuclear factor kappa-B ligand; osteoprotegerin; ovariectomized mice; palmatine; postmenopausal osteoporosis.