Fig. 4

The therapeutical effect of hUCMSC-EVs to S. japonicum-mediated hepatic fibrosis after praziquantel therapy. a Time schedule for parasite infection and intravenous injections of PBS, hUCMSCs, or hUCMSC-EVs. Mice were infected percutaneously with 20 S. japonicum cercariae. The infected mice were treated with praziquantel (PZQ) to kill the adult worms, and then received hUCMSCs, hUCMSC-EVs, or PBS by tail infection at day 42/49/56/63 post-infection. Liver and serum samples of the mice were collected at day 70 post-infection. MSCs, hUCMSCs; EVs, hUCMSC-EVs. b The appearance of liver from each group. c HE and Masson’s trichrome staining of liver sections. Scale bar = 200 μm. d Mean area of granuloma determined from HE staining liver sections. e Fibrosis score measured from Masson’s trichrome staining liver sections. f Collagen content of the livers was detected as hydroxyproline content. Levels of g ALT and h AST in serum. i The number of schistosome eggs in the liver was measured after the liver tissue was digested by 4% KOH. Mean values ± SD for three independent experiments are shown, *P < 0.05; **P < 0.01; ***P < 0.001, compared with the PBS group