Curcuma Longa Administration Significantly Reduces Acute and Persistent Inflammatory Pain Measures in Male and Female Rats

Pain management is a worldwide public health concern particularly in women given its high prevalence and severity. Moreover, current pharmaceuticals induce numerous side effects including dependence and tolerance. Therefore, the search for novel therapeutic targets for the treatment of various forms of pain is of foremost importance. In this regard, Curcuma longa (C. longa) or turmeric has shown anti-inflammatory and immunomodulatory effects. Henceforth, in this work, we evaluate the potential anti-nociceptive and anti-inflammatory effects of C. longa in two models of peripheral inflammation in male and female rats. Rats were administered with the inflamogens carrageenan (acute inflammation inducer) and complete Freund’s adjuvant (CFA) (persistent inflammation inducer) in the hindpaw to elicit mechanical allodynia and paw oedema. At the peak of mechanical allodynia, C. longa was administered orally and mechanical thresholds and paw size were monitored until the mechanical thresholds were back to baseline values. C. longa reduced mechanical allodynia in rats with acute or persistent inflammation-induced allodynia in male and female rats to a similar degree. This is the first study to employ a combination of pharmacodynamic models of acute and persistent inflammation to assess efficacy of C. longa on inflammatory pain behavior, also considering sex differences. We found that C. longa reverses inflammation-induced mechanical allodynia in male and female rats therefore showing promise as an effective anti-nociceptive agent. When using the carrageenan and CFA models, both male and female rats can be used without concerns related to sex bias.