Rosmarinic acid improves cyclophosphamide-induced immunosuppression in mice by immunomodulatory and antioxidant effects

Rosmarinic acid (RA) has various pharmacological effects, such as hypolipidemic and antitumor effects; however, its role in immunomodulation is not fully understood. Therefore, in this study, we established a cyclophosphamide-induced immunosuppressive mouse model to study the effects of RA on immune function. The results showed that RA alleviated the slow increase in body weight, increased the immune organ index, and improved the histopathological status of immunosuppressed mice. Furthermore, it can restore peripheral blood levels and enhance the activity of lymphocytes, NK cells, and CTL, as well as the secretion and mRNA expression of immune-related cytokines. Moreover, it improved oxidative stress and promoted phosphorylation of the splenic PI3K/Akt signaling pathway. In summary, RA plays a positive role in the immune response, and its potential mechanism may be related to the regulation of the PI3K/Akt signaling pathway. Thus, RA could be developed as an immunomodulator for functional food and nutraceutical applications.