# Attenuated RANKL-induced cytotoxicity by Portulaca oleracea ethanol extract enhances RANKL-mediated osteoclastogenesis

## TL;DR

This study shows that Portulaca oleracea extract reduces RANKL-induced cell death and promotes osteoclast formation, which could help treat bone disorders.

## Contribution

The study reveals a novel effect of Portulaca oleracea extract on RANKL-mediated osteoclastogenesis and cytotoxicity.

## Key findings

- POEE suppressed RANKL-induced Ca2+ oscillations and NFATc1 amplification.
- POEE reduced RANKL-mediated cytotoxicity and PARP cleavage.
- POEE enhanced the formation of TRAP+ multinucleated cells.

## Abstract

Portulaca oleracea (PO) has been widely used as traditional medicine because of its pharmacological activities. However, the effects of PO on osteoclasts that modulate bone homeostasis are still elusive.

In this study, we examined the effects of PO ethanol extract (POEE) on receptor activator of nuclear factor-κB ligand (RANKL)-mediated Ca2+ mobilization, nuclear factor of activated T-cell c1 (NFATc1) amplification, tartrate-resistant acid phosphatase-positive (TRAP+) multinucleated cell (MNC) formation, and cytotoxicity.

Our results demonstrated that POEE suppressed RANKL-induced Ca2+ oscillations by inhibition of Ca2+ release from internal Ca2+ stores, resulting in reduction of NFATc1 amplification. Notably, POEE attenuated RANKL-mediated cytotoxicity and cleavage of polyadenosine 5′-diphosphate-ribose polymerase (PARP), resulted in enhanced formation of TRAP+ MNCs.

These results present in vitro effects of POEE on RANKL-mediated osteoclastogenesis and suggest the possible use of PO in treating bone disorders, such as osteopetrosis.