Anti-Inflammatory Effects of Ivermectin in Carrageenan-Induced Paw Edema in Rats

Introduction: Ivermectin has shown potential anti-inflammatory properties in some studies, although the results are conflicting. Therefore, this study investigated the anti-inflammatory effects of ivermectin in rats using the carrageenan-induced paw edema model. Methods: Thirty male Wistar rats were randomly assigned to carrageenan, dimethyl sulfoxide, and indomethacin groups and two ivermectin-treated (at ۰.۲ mg/kg and ۱۰ mg/kg doses) groups (n=۶ each). Paw edema was induced by the subcutaneous injection of carrageenan, and ivermectin was intraperitoneally injected at doses of ۰.۲ mg/kg and ۱۰ mg/kg. Then, paw thickness was hourly measured for ۵ hours. Finally, myeloperoxidase (MPO) activity, malondialdehyde (MDA) levels, and histopathological changes in paw tissues underwent assessment. Results: At the second hour post-carrageenan injection, ivermectin at ۰.۲ mg/kg (P<۰.۰۱) reduced inflamed paw thickness. At the third hour, ivermectin at ۰.۲ mg/kg (P<۰.۰۰۱) and ۱۰ mg/kg (P<۰.۰۱) also decreased inflamed paw thickness. Likewise, both doses of ivermectin (P<۰.۰۱) contributed to a similar extent to diminishing inflammation at the fourth hour. Moreover, ivermectin at doses of ۰.۲ mg/kg and ۱۰ mg/kg could reduce MPO activity (P<۰.۰۱) and MDA levels (P<۰.۰۱), respectively. Ultimately, histopathological evaluation revealed a dose-dependent decline in leukocyte infiltration and inflammation in ivermectin-treated rats. Conclusion: Ivermectin demonstrated anti-inflammatory activity by decreasing paw edema, oxidative stress, neutrophil activity, and leukocyte infiltration, suggesting its potential as an anti-inflammatory agent.