Anti-inflammatory and neuroprotective effect of a phytoestrogen compound on rat microglia

Ovariectomized Wistar rats received orally 15 mg/kg of a phytoestrogen compound (genistein, daidzein, glycitein, black cohosh, angelica sin., licorice, vitex agnus) for 2 weeks to test its ability to modulate inflammatory microglia response. Microglial proliferation was tested by trypan blue and by absorbance. Serial supernatant sampling was performed for 24 h to check TNF-alpha, IL-beta, IL-6, and TGF-beta. LPS caused a time course increase of all cytokines, with IL-beta and TNF-alpha peaking at the 12th hour, whereas IL-6 and TGF-beta peaked at the 24 h observation. Rats fed with the phytoestrogen displayed a significantly lower level of proinflammatory cytokines and a higher level of TGF-beta, as shown also by Western blot analysis. This finding may offer promise in the field of nutraceutical intervention.