Cucurbita pepo Seed Oil Induces Microsatellite Instability and Tegumental Damage to Schistosoma mansoni Immature and Adult Worms In vitro

Treating Hymenolepiasis with Pumpkin Seeds: Effect on Ileum Histology and Dwarf Tapeworm Morphology

BACKGROUND

Hymenolepis nana is a worldwide intestinal tapeworm parasite that mainly infects children due to a lack of awareness and hygiene. Recently, Praziquantel (PZQ), the drug of choice for treating hymenolepiasis, has shown serious side effects. This study aimed to evaluate histological changes in the ileum of the small intestine caused by hymenolepiasis in an experimental animal model and to assess the efficacy of pumpkin seeds extract (PSE) in eliminating the parasite at different periods compared to medicinal treatment with PZQ drug. In addition, we investigated the morphological alterations in adult dwarf tapeworms after treatment with pumpkin seed extract.

METHODS

The histological examination of the small intestine was conducted among four experimental mice groups: normal non-infected control group, infected untreated group, infected and PZQ treated group, and the fourth group was infected and treated with PSE.The morphological investigations were performed on mice from the infected untreated group and those from the infected and treated with pumpkin seed extract group.

RESULTS

Treatment with PSE showed a noticeable preservation of the normal structure of villi and crypts with a normal thickness of the muscle layer. In addition, there was a marked decrease in the number of mononuclear leukocytes and goblet cells. This effect was observed to be duration dependent. The size of the mature segment in the untreated control group ranged from 342.85 to 415.38 μm, and 14.28-26.92 μm in length and width, respectively. The gravid segments revealed a uterus with eggs subjugating the entire area in the segment, with size ranges from 373.33 to 576.92 μm in length and 46.66-76.92 μm in width. The treated group with PSE showed mature segments with size ranged from 261.53 to 346.42 μm in length and 7.69-21.42 μm in width, while the gravid segments ranged from 30.76 to 50 μm and 414.28-492.30 μm, in width and length, respectively. The treatment with pumpkin seed extract tenanted the worm growth through an apparent reduction in the sizes of proglottids, deformity of the lateral margins and gonads, loss of internal structure, and reduction of egg production.

CONCLUSION

The results of this study clearly reveal the efficacy of pumpkin seeds on H. nana infection, a promising, safe, inexpensive natural alternative anthelmintic therapy, with more superior and significant results in improving and protecting mucosal integrity in comparison to PZQ.

Computer-Aided Discovery of Abrus precatorius Compounds With Anti-Schistosomal Potential

Schistosomiasis, which causes over 200 000 deaths annually, has since the 1970s been controlled by praziquintel. The reliance on a single drug to combat schistosomiasis, and reports of laboratory resistance to the drug, has created an urgent need in the scientific community to develop new chemotherapies to complement or supplement praziquantel. Medicinal plants are a potential reservoir of compounds with schistosomicidal activity. In the current study, we carried out computer-aided screening of Abrus precatorius compounds to discover compounds with potential to inhibit Schistosoma mansoni purine nucleoside phosphorylase (SmPNP). Thus, 99 compounds retrieved from Lotus Natural Compounds Database were docked into the active site of SmPNP. The top-ranked compounds were subjected to Lipinski's druglikeness and toxicity risk predictions. Three lead compounds, abrusogenin, cirsimaritin and hispidulin, were identified as having high binding affinities, favourable interactions with SmPNP active site residues and good toxicity risk prediction results. Molecular dynamics (MD) simulations were used to assess the stability of the interactions of these lead compounds with SmPNP. Collectively, analyses of the MD trajectories confirms that the lead compounds bound and interacted stably with active site residues of SmPNP. We conclude that abrusogenin, cirsimaritin and hispidulin could serve as hit compounds for the development of new antischistosomal drugs, based on plant-derived natural products. However, experimental studies are required to further evaluate the potentials of these compounds as possible therapeutics against schistosomiasis.

In Silico Study of Cucurbita maxima Compounds as Potential Therapeutics Against Schistosomiasis

Schistosomiasis, a disease usually related to poverty and poor sanitation, affects more than 200 million people worldwide. Since the 1970s, the medical sector has depended on a single drug, praziquantel, for the treatment of the disease. The emerging evidence of resistance of the Schistosoma parasite to praziquantel and the drug’s inefficacy against juvenile stages of the parasite makes the need to find alternative drugs an urgent matter. In this study, we explored the inhibition potential of compounds from Cucurbita maxima using molecular docking studies on Schistosoma mansoni purine nucleoside phosphorylase ( SmPNP) and Schistosoma haematobium 28-kDa glutathione S-transferase ( Sh28kDaGST). Following molecular docking studies and analysis of the active sites, the primary amino acids that were observed and shown to be involved in the SmPNP-ligand interaction are CYS 33, ARG 86, HIS 88, TYR 90, ALA 118, ALA 119, PRO 200, TYR 202, GLU 203, VAL 219, MET 221, THR 244, ASN 245, PRO 257 and HIS 259. For the Sh28dKa-ligand interaction, the primary amino acids were PHE 11, ARG 16, TRP 41, LEU 53, GLU 70 and SER 71. Momordicoside I aglycone binds to SmPNP with the lowest binding affinity of -7.9 kcal/mol by pi sigma bond interactions with HIS 88. Balsaminoside B binds to Sh28kDaGST with a binding affinity of −7.6 kcal/mol by hydrogen bond interaction with TRP 41, LEU 53 and SER 71. Pharmacokinetic studies showed favourable drug-like properties for the 10 compounds that exhibited the lowest binding energies. Therefore, we propose that bioactive compounds from C. maxima be considered as potential novel drug hits in the treatment of schistosomiasis.

Fifty years of the schistosome tegument: discoveries, controversies, and outstanding questions

The unique multilaminate appearance of the tegument surface of schistosomes was first described in 1973, in one of the earliest volumes of the International Journal for Parasitology. The present review, published almost 50 years later, traces the development of our knowledge of the tegument, starting with those earliest cytological advances, particularly the surface plasma membrane-membranocalyx complex, through an era of protein discovery to the modern age of protein characterization, aided by proteomics. More recently, analysis of single cell transcriptomes of schistosomes is providing insight into the organisation of the cell bodies that support the surface syncytium. Our understanding of the tegument, notably the nature of the proteins present within the plasma membrane and membranocalyx, has provided insights into how the schistosomes interact with their hosts but many aspects of how the tegument functions remain unanswered. Among the unresolved aspects are those concerned with maintenance and renewal of the surface membrane complex, and whether surface proteins and membrane components are recycled. Current controversies arising from investigations about whether the tegument is a source of extracellular vesicles during parasitism, and if it is covered with glycolytic enzymes, are evaluated in the light of cytological and proteomic knowledge of the layer.