Protein undernutrition reduces the efficacy of praziquantel in a murine model ofSchistosoma mansoniinfection
Authors: Kadji Fassi Joseph Bertin , Boukeng Jatsa Hermine , Membe Femoe Ulrich , Greigert Valentin , Brunet Julie , Cannet Catherine , Kenfack Christian Mérimé , Gipwe Feussom Nestor , Tienga Nkondo Emilienne , Abou-Bacar Ahmed , Pfaff Alexander Wilhelm , Kamgang René , Kamtchouing Pierre , Tchuem Tchuenté Louis-Albert 
Published: February 2022

Background

Undernutrition and schistosomiasis are public health problems and often occur in low and middle-income countries. Protein undernutrition can alter the host-parasite environment system and aggravate the course of schistosomiasis. This study aimed to assess the impact of a protein-deficient diet on the efficacy of praziquantel.

Methodology/principal findings

Thirty-day-old mice were fed with a protein-deficient diet, and 40 days later, they were individually infected with fiftySchistosoma mansonicercariae. A 28-day-treatment with praziquantel at 100 mg/kg for five consecutive days followed by distilled water begins at the 36thday post-infection. Mice were sacrificed on the 64thday post-infection. We determined the parasitological burden, liver and intestine histomorphometry, liver injury, and immunomodulation parameters. Praziquantel treatment of infected mice fed with a standard diet (IN-PZQ) resulted in a significant reduction of worm and egg burdens and a normalization of iron and calcium levels. The therapy also improved schistosomiasis-induced hepatopathy and oxidative stress. The anti-inflammatory and immunomodulatory activities of praziquantel were also significant in these mice. When infected mice receiving the protein-deficient diet were treated with praziquantel (ILP-PZQ), the body weight loss and hepatomegaly were not alleviated, and the worm and liver egg burdens were significantly higher than those of IN-PZQ mice (P< 0.001). The treatment did not reduce the increased activities of ALT and γ-GGT, the high malondialdehyde concentration, and the liver granuloma volume. The iron and calcium levels were not ameliorated and differed from those of IN-PZQ mice (P< 0.001 andP< 0.05). Moreover, in these mice, praziquantel treatment did not reverse the high level of IL-5 and the low mRNA expression of CCL3/MIP-1α and CXCL-10/IP-10 induced byS. mansoniinfection.

Conclusion/significance

These results demonstrated that a protein-deficient diet reduced the schistosomicidal, antioxidant, anti-inflammatory, and immunomodulatory activities of praziquantel.

Authors summary

Almost 90% of people requiring schistosomiasis preventive chemotherapy in 2018 lived in sub-Saharan Africa. Besides, 205.3 million children under five years suffer and die of undernutrition in low- and middle-income countries. The physiopathology of schistosomiasis mansoni involves liver damage, oxidative stress, and perturbation of the immune response. These disturbances are intensified by undernutrition. Praziquantel is used to treat schistosomiasis, but its efficacy on the comorbidity ofS. mansoniinfection and undernutrition has not been investigated. We conducted this study to assess the effectiveness of praziquantel onS. mansoniinfection in mice fed with a protein-deficient diet. We recorded growth retardation, hepatomegaly, and high worm and egg burdens in mice fed with a protein-deficient diet and treated with PZQ. Moreover, the treatment did not reverse the liver function injury, oxidative stress, high iron level, and low calcium level. The proinflammatory cytokine IL-5 was still high, and the gene expression of some macrophage-associated chemokines was reduced. Therefore, this study demonstrated that in a murine model of a protein-deficient diet, the efficacy of praziquantel onS. mansoniinfection was reduced. It also underlines the importance of targeting protein deficiency and malnutrition in populations living in schistosomiasis endemic areas for efficient disease control.