An adjuvant effect of Metformin as an anti-fibrotic agent when administered with the anti-schistosomal Praziquantel in Schistosoma mansoni infected mice

@#Schistosomiasis is the second most common parasitic disease post Malaria around the world. Praziquantel (PZQ) is known as the most efficient anti- schistosomal drug but has no anti-fibrotic effect. Metformin (Met) is a well-known drug for type 2 diabetes. This study aimed to evaluate the role of Met as anti-schistosomal and anti-fibrotic agents alone or in combination with PZQ treatment. Forty male CD1 mice were divided into four groups (n=10 mice) as following; the first group (Gp1) was served as a negative control. Gp2, Gp3, Gp4, and Gp5 were infected with (60-80) S. mansoni cercariae. After a month of infection, Gp3 was administered orally with PZQ (500 mg/Kg) for 2 consecutive days. Gp4 was administered orally with Met (150 mg/Kg) for 15 consecutive days, and Gp5 was orally administered with PZQ followed by Met for 15 consecutive days at the same doses as in Gp 3 and 4. The results showed that PZQ had potent worms and egg reduction in liver and intestine tissues with no anti-fibrotic effect of the granuloma formation. However, Met or PZQ/Met treatment postinfection led to a reduction in egg count in both liver and intestine tissues with a significant reduction in granuloma site. Treatment of S. mansoni-infected mice with Met or PZQ/Met ameliorated the hematological and biochemical alterations induced by S. mansoni infection. Collectively, Met has no anti-schistosomal activity but led to a reduction in egg deposition and showed an anti-fibrotic effect on granulomatous development either when used alone or in combination with PZQ treatment. This study shed light on the possible role of Met as an anti-fibrotic agent when administered with PZQ for S. mansoni infected humans.

Ortho-nitrobenzyl derivatives as potential anti-schistosomal agents

ABSTRACT In the search for new anti-schistosomal agents, a series of fifteen ortho-nitrobenzyl derivatives was assayed in vitro against both the schistosomulum (somule) and adult forms of Schistosoma mansoni. Compounds 8 and 12 showed significant activity against somules at low micromolar concentrations, but none was active against adults. The SAR demonstrated that the compounds most active against the parasite were mutagenic to the human cell line RKO-AS45-1 only at concentrations 10- to 40-fold higher than the worm-killing dose. Given their electrophilicity, compounds were also screened as inhibitors of the S. mansoni cysteine protease (cathepsin B1) in vitro. Amides 5 and 15 exhibited a modest inhibition activity with values of 55.7 and 50.6 % at 100 µM, respectively. The nitrobenzyl compounds evaluated in this work can be regarded as hits in the search for more active and safe anti-schistosomal agents.