osteoclasts

Scutellarin (Scutellarein-7-glucuronide), an active flavone isolated from Scutellaria baicalensis, can inhibit RANKL-mediated MAPK and NF-κB signaling pathway in osteoclasts, and down-regulate the STAT3 Girdin Akt signaling in HCC cells.

Amakusamine is an indole alkaloid from the sponge of Psammocinia sp. It inhibits RANKL-induced isolation of multinucleated osteoclasts and inhibits RANKL-induced multinucleated osteoclasts.

Icariside I (Lcariside I) is isolated from Epimedium herb. It can stimulate osteogenic differentiation of BMSCs and inhibit bone resorption activity of osteoclasts.

Reveromycin A is the major component of a complex of spiroketal antibiotics isolated from Streptomyces sp. It inhibits the mitogenic activity of epidermal growth factor in Balb MK cells (IC50 = 0.7 μg ml), displays antiproliferative activity against human KB and K562 tumor cell lines (IC50s = 1.9 and 1.6 μg ml, respectively), and demonstrates antifungal activity against C. albicans (MIC = 2 μg ml at pH 3). Reveromycin A also has been shown to inhibit bone resorption by inducing apoptosis in osteoclasts with an IC50 value of 0.7 μM.

Alisol B may be a potential novel therapeutic molecule for bone disorders through targeting the differentiation of osteoclasts as well as their functions. Alisol B also inhibited RANKL-induced expression of NFATc1 and c-Fos, which are key transcription factors for osteoclastogenesis.

Cheilanthifoline has anti-osteoclastogenic property, it gives significant inhibitions on receptor activator of nuclear factor-κB ligand-induced differentiation of mouse bone marrow-derived macrophages into multinucleated osteoclasts.

Gossypetin, a hexahydroxylated flavonoid extractable from Rhodiola rosea Linn. is a potent MKK3 and MKK6 inhibitor that strongly attenuates the MKK3 6-p38 signaling pathway.Gossypetin exhibits antimutagenic, antiatherosclerotic, antioxidant, as well as cytoprotective and antimicrobial effects.It inhibits bone resorption by downregulating lysosomal caspase K activity and inducing autophagy-associated proteins in actin ring osteoclasts. Gossypetin has anti-mutagenic, anti-atherosclerotic, anti-oxidant, cytoprotective and antibacterial effects, and it inhibits bone resorption by down-regulating lysosomal caspase K activity and by inducing autophagy-associated protein in actin ring osteoblasts.

Toddaculine may be beneficial for the prevention and treatment of osteoporosis, it can not only inhibit the differentiation of osteoclasts via activation of the NF-κB, ERK 1 2, and p38 MAPK signaling pathways, but can induce differentiation and mineralization of osteoblasts by regulating differentiation factors. Toddaculine also may serve as a pharmacological prototype for the development of novel anti-leukemic agents, it displays a dual effect as a cell differentiating agent and apoptosis inducer in U-937 cells.