Safety evaluation of a potential anti-rheumatoid arthritis candidate, levamisole

Backgrounds: Levamisole (LVM) is a non-specific immunomodulator with potential for treating skin conditions, tumors, and autoimmune disorders. However, the widespread reports of neurotoxicity caused by LVM as a cutting agent for cocaine have led to public panic and restricted its clinical use. Methods : To investigate the potential toxicity of LVM and evaluate its effects in treating rheumatoid arthritis (RA), we conducted a 28-day oral administration study in SD rats, and assessed general toxicity and neurotoxicity via serum biochemical indicators, the Morris water maze test, transmission electron microscopy, and H&E staining. Subsequently, we evaluated the therapeutic effects of LVM on RA. Results : In the LVM toxicity study, there were no significant differences in the histopathological slices, serum biochemical tests, and behavioral experiments of the treatment group compared to the control group; in the study of treating RA, LVM not only significantly improved the bone and joint erosion in rats induced by adjuvant, but also significantly reduced synovial hyperplasia and infiltration of inflammatory cells Conclusions : This study showed that LVM has promising therapeutic effects in treating RA with negligible toxicity, and offer valuable insights for the clinical use of LVM in treating RA.