The inhibitory extractsalso contained a relative abundance of the gallotannin components gallic acid (Fig. 4b) and chebulic acid (Fig. 4q). Gallotannins have been reported to inhibit the growth of a broad spectrum of microbial species through a variety of mechanisms including binding cell surface molecules including lipotoichoic acid and proline-rich cell surface proteins and by inhibiting glucosyltransferase enzymes. Whilst we were unable to find similar studies reporting inhibitory effects of tannins on Giardia spp. growth, a number of studies have reported high tannin contents in a variety of plants used in traditional medicine to treat giardiasis. Furthermore, tannins extracted from other plant species inhibit the growth of other protozoa including Schistosoma mansoni (the parasite responsible for schistosoma).