Comparison of the Immunomodulatory Properties of Root and Leaves of Arctium Lappa (Burdock) in Vitro

Background: The roots and leaves of Arctium lappa (burdock) have been used for different therapeutic purposes, especially for diseases linked to chronic inflammation. Objectives: The present study was designed to evaluate and compare the immunomodulatory activities of root extract of burdock and leaves extract of burdock in vitro. Methods: In this experimental study, PHA- or LPS-stimulated splenocytes were treated with different concentrations of root or leaves extract of burdock and proliferation of splenocytes measured by MTT assay. The levels of IFN-γ and IL4 in the supernatants of PHA-stimulated splenocytes determined using ELISA. We also studied the effects of root and leaves extract of burdock on Nitric Oxide production by LPS-stimulated macrophages using the Griess reagent. The data were analyzed by one-way ANOVA followed by Tukey’s post-test using GraphPad Prism software, version 5.0. Results: Our findings showed that both root and leaves extract of burdock have suppressive effects on LPS-stimulated splenocytes proliferation, IL-4 secretion from PHA-stimulated splenocytes, and NO production from LPS-stimulated macrophage and stimulatory effects on PHA-stimulated splenocytes proliferation, and IFN-γ secretion from PHA-stimulated splenocytes. Although both root and leaves extract of burdock had similar immunomodulatory effects in vitro, stronger immunomodulatory effects seen in root extract of burdock. Conclusions: According to our results, we suggest that root of burdock is better option than leaves of burdock in modulation immune responses and inflammations.