CTSB and amebiasis: Moreover, literature reports of natural products effective against N. fowleri growth have been limited [28, 72] and our study has identified relatively potent compounds from L. tridentata that have amebicidal activity against N. fowleri, which we show may be due to inhibiting cysteine protease activity present in the lysate of N. fowleri. Therefore, lignan secondary metabolites from the creosote bush represent a class of natural products pharmacophore that can be optimized through medicinal chemistry to translate more effective therapeutic options for amebiasis, giardiasis, and PAM.