β-Elemene alleviates bone cancer-related pain in rats by modulating N-methyl-D-aspartate receptor 2B subunit

Purpose: To investigate the effect of beta-eiemene on bone cancer-related pain (BCRP) and its underlying mechanism in a rat model. Methods: A rat model of BCRP was established by injection of Walker 256 cells into the medullary cavity in adult male Sprague-Dawley rats. The effects of beta-elemene on pain-related behaviours were assessed by paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL). Quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting were used to analyse the transcription and translation levels of N-methyl-D-aspartate receptor 2B subunit (NR2B), respectively. Results: This study found that PWMT and PWTL were significantly decreased in rats as evidence of successful establishment of a rat model of BCRP. Behavioral test showed that beta-elemene treatment could attenuate pain-related behaviours. This analgesic effect began 1 h after drug injection, reached the highest value at 2 h, declined at 4 h, and disappeared by 24 h. qRT-PCR and western blotting indicated that intrathecal administration of beta-elemene down-regulated mRNA and protein levels of NR2B. Conclusion: The results show that /3-elemene alleviates behaviours related to pain in a rat model of BCRP probably by modulating NR2B, thus indicating a new potential treatment method for cancer-related pain.