Figure 6. Ergotamine resolves infections and mitigates pathology of schistosomiasis in vivo.

(A) Survival of mice infected with S. mansoni and treated for one week (days 42–49 post infection) with either vehicle control (DMSO. n = 26 mice), ergotamine (ERG, 60 mg/kg twice daily. n = 22 mice) or praziquantel (PZQ, 50 mg/kg daily. n = 10 mice). (B) Worm burden of mice treated as in A and sacrificed 49 days post-infection. (C) Intestinal egg counts of mice sacrificed in B. (D) Representative livers and spleens from uninfected mice and infected mice exposed to vehicle (DMSO), ergotamine (ERG) or praziquantel (PZQ). Quantification of hepatomegaly (E) and splenomegaly (F) in uninfected mice (open columns) and infected mice following drug treatment (solid columns). (G) Histology of liver sections control uninfected and infected (DMSO) mice, as well as drug treated (ERG and PZQ) infected animals (scale = 1 mm). Liver histology using (I) H and E staining, (II) Movat’s stain (collagen, yellow), (III) Masson’s trichrome stain (collagen, blue), (IV) aldehyde fuchsin stain (elastin, purple), (V) Oil red O stain (lipid, red), and (VI) caspase-3 activation (brown puncta, arrows). Higher magnification images of egg granulomas for each staining condition are shown in Figure 6—figure supplement 2.

Figure 6—figure supplement 1. Ergotamine inhibition of S. mansoni egg laying during ex vivo culture.

(A) Eggs laid by adult S. mansoni cultured ex vivo as male and female pairs. (B) Average number of eggs laid per worm pair over the course of five days for worms treated with DMSO (0.1% v/v), ergotamine (ERG, 1 µM), forskolin (FSK, 100 µM), serotonin (5-HT, 100 µM) or praziquantel (PZQ, 1 µM). (C) Dose response for ergotamine inhibition of egg laying. (D) Morphological changes in eggs laid by ergotamine (1 µM, blue circles) treated worms relative to control (open circles). Data reflects mean ± standard error of at least 3 biological replicates.

Figure 6—figure supplement 2. Liver egg granulomas in control and drug treated mice.

Histology of sections of liver from uninfected mice and infected mice treated with DMSO, ergotamine (ERG, 60 mg/kg), praziquantel (PZQ, 50 mg/kg). (I) H and E staining, (II) Movat’s stain (collagen, yellow), (III) Masson’s trichrome stain (collagen, blue), (IV) aldehyde fuchsin stain (elastin, purple), (V) Oil red O stain (lipid, red), and (VI) caspase-3 activation (brown puncta). Scale = 500 µm.

Figure 6—figure supplement 3. Effects of ergotamine on immature S. mansoni.

Schistosomes were harvested from mice 4 weeks post infection and the movement of male worms was assayed in response to (A) serotonin (5-HT) and (B) ergotamine (ERG). (C) Effect of ergotamine (ERG, 60 mg/kg) and the anthelmintics praziquantel (PZQ, 50 mg/kg) and artemether (ART, 100 mg/kg) on schistosome infection in vivo. Drugs were administered to mice between weeks 3–4 post-infection, and animals were euthanized at 7 weeks post-infection to assess worm burden. Open circles = worm burdens of individual mice, bars = mean values. N.S. = not significant. **p<0.001.

Figure 6—figure supplement 4. Lack of hepatic microvesicular steatosis in drug treated livers.

Histological H and E staining of formalin fixed, paraffin embedded liver sections from uninfected mice and infected mice treated with DMSO, ergotamine (ERG, 60 mg/kg), praziquantel (PZQ, 50 mg/kg). Scale = 50 µm.