Study on alleviate effect of Wuzhi capsule (Schisandra sphenanthera Rehder & E.H. Wilson extract) against mycophenolate mofetil-induced intestinal injury.

ETHNOPHARMACOLOGICAL RELEVANCE: Schisandra sphenanthera Rehder & E.H. Wilson (S. sphenanthera) is a botanical medicine included in the 2020 edition of the ChP that has a variety of medicinal activities, including hepatoprotective, anticancer, antioxidant and anti-inflammatory properties. Wuzhi capsule (WZ) is a proprietary Chinese medicine made from an ethanolic extract of S. sphenanthera that is commonly used to treat drug-induced liver injury. However, there are no research reports exploring the effects of WZ on the prevention of mycophenolate mofetil (MMF)-induced intestinal injury and its underlying mechanisms. AIM OF THE STUDY: This experiment aimed to evaluate the ameliorative effect of WZ on MMF-induced intestinal injury in mice and its underlying mechanisms. MATERIALS AND METHODS: A mouse model of MMF-induced intestinal injury was established and treated with WZ during the 21-day experimental period. The pathological characteristics of the mouse ileum were observed. Tight junction (TJ) protein changes were observed after immunofluorescence staining and transmission electron microscopy, and ROS levels were measured by using DHE fluorescent dye and the TUNEL assay for apoptosis. The expression of p65, p-p65, IκBα, p-IκBα, the TJ proteins occludin and ZO-1 and the apoptosis-related proteins Bax, Bcl-2, cleaved caspase-3 and caspase-3 were analysed by Western blot. Levels of DAO, ET, TNF-α, IL-1ß, IL-6, IFN-γ, MDA and SOD were analysed by using kits. RESULTS: MMF activated the NF-κB signaling pathway to cause intestinal inflammation, increased intestinal permeability, changed the expression of TJ protein in the intestinal epithelium, and increased oxidative stress and apoptosis levels. WZ significantly downregulated the expression of p-p65 and p-IκBα to relieve the inflammatory response, reduced intestinal permeability, maintained intestinal TJ protein expression, and reduced intestinal oxidative stress and apoptosis. CONCLUSION: Our research suggested that MMF can cause intestinal injury; by contrast, WZ may exert anti-inflammatory, antioxidant and apoptosis-reducing effects to alleviate MMF-induced intestinal injury.

Drug screening of food and drug administration-approved compounds against Babesia bovis in vitro.

Babesia (B.) bovis is one of the main etiological agents of bovine babesiosis, causes serious economic losses to the cattle industry. Control of bovine babesiosis has been hindered by the limited treatment selection for B. bovis, thus, new options are urgently needed. We explored the drug library and unbiasedly screened 640 food and drug administration (FDA) approved drug compounds for their inhibitory activities against B. bovis in vitro. The initial screening identified 13 potentially effective compounds. Four potent compounds, namely mycophenolic acid (MPA), pentamidine (PTD), doxorubicin hydrochloride (DBH) and vorinostat (SAHA) exhibited the lowest IC50 and then selected for further evaluation of their in vitro efficacies using viability, combination inhibitory and cytotoxicity assays. The half-maximal inhibitory concentration (IC50) values of MPA, PTD, DBH, SAHA were 11.38 ± 1.66, 13.12 ± 4.29, 1.79 ± 0.15 and 45.18 ± 7.37 µM, respectively. Of note, DBH exhibited IC50 lower than that calculated for the commonly used antibabesial drug, diminazene aceturate (DA). The viability result revealed the ability of MPA, PTD, DBH, SAHA to prevent the regrowth of treated parasite at 4 × and 2 × of IC50. Antagonistic interactions against B. bovis were observed after treatment with either MPA, PTD, DBH or SAHA in combination with DA. Our findings indicate the richness of FDA approved compounds by novel potent antibabesial candidates and the identified potent compounds especially DBH might be used for the treatment of animal babesiosis caused by B. bovis.

Accuracy, discriminative properties and reliability of a human ESC-based in vitro toxicity assay to distinguish teratogens responsible for neural tube defects.

The poor correlation of developmental toxicity studies in animals with human outcome data has emphasized the need for complementary assays based on human cells and tissues. As neural tube defects represent an important proportion of congenital malformations, we evaluated here the accuracy of a human embryonic stem cell (hESC)-based assay to predict chemically induced disruption of neural tube formation. As teratogenic compounds, we used cyclopamine (CPA), valproic acid (VPA), ochratoxin A (OTA) and mycophenolic acid (MMF), all suspected or known inducers of human neural tube defects, as well as theophylline and saccharin as negative control compounds. We analyzed their effects on the ability of hES cells to give rise to neural precursors (expressing specific marker Nestin), to form neural tube-like structures (rosettes), and to express specific markers (Sox1, Otx2, Lix1, EvI1, Rspo3) during rosette formation. The results showed that various effects of the selected compounds on early neural development could be specifically revealed in vitro through related alterations of neurogenic differentiation of hESC. Furthermore, it was possible to discriminate toxicants acting at different time points during embryonic development and, therefore, responsible for distinct adverse effects on neural tube formation. By comparing four different hESC lines, we observed a significant (up to fivefold) variability of the line-dependent response to toxicants. We highlight at least two sources of variability: one related to the heterogeneity of hESC lines in culture (stemness/commitment profiles); the second to possible genetically determined differences in individual sensitivity to teratogens.

Hirschsprung-like disease is exacerbated by reduced de novo GMP synthesis.

Hirschsprung disease (HSCR) is a partially penetrant oligogenic birth defect that occurs when enteric nervous system (ENS) precursors fail to colonize the distal bowel during early pregnancy. Genetic defects underlie HSCR, but much of the variability in the occurrence and severity of the birth defect remain unexplained. We hypothesized that nongenetic factors might contribute to disease development. Here we found that mycophenolate, an inhibitor of de novo guanine nucleotide biosynthesis, and 8 other drugs identified in a zebrafish screen impaired ENS development. In mice, mycophenolate treatment selectively impaired ENS precursor proliferation, delayed precursor migration, and induced bowel aganglionosis. In 2 different mouse models of HSCR, addition of mycophenolate increased the penetrance and severity of Hirschsprung-like pathology. Mycophenolate treatment also reduced ENS precursor migration as well as lamellipodia formation, proliferation, and survival in cultured enteric neural crest­derived cells. Using X-inactivation mosaicism for the purine salvage gene Hprt, we found that reduced ENS precursor proliferation most likely causes mycophenolate-induced migration defects and aganglionosis. To the best of our knowledge, mycophenolate is the first medicine identified that causes major ENS malformations and Hirschsprung-like pathology in a mammalian model. These studies demonstrate a critical role for de novo guanine nucleotide biosynthesis in ENS development and suggest that some cases of HSCR may be preventable.

The new malononitrilamide immunosuppressant FK778 prolongs corneal allograft survival in the rat keratoplasty model.

PURPOSE: Aim of this study was to prove the efficacy and safety of the new malononitrilamide immunosuppressive FK778 in prolonging clear graft survival following allogeneic orthotopic keratoplasty in rats. METHODS: Sixty-seven penetrating keratoplasties were performed using Fisher and Lewis rats as donors and recipients, respectively: group 1 (n=11), allogeneic control without therapy; group 2 (n=12), syngeneic control; group 3 (n=11), mycophenolate mofetil (MMF) 40 mg/kg bodyweight; group 4 (n=12), FK778 5 mg/kg bodyweight; group 5 (n=12), FK778 10 mg/kg bodyweight; and group 6 (n=9), FK778 20 mg/kg bodyweight. Four animals in each group were killed for immunohistological evaluation on day 14. Therapy was administered orally for 18 days. The grafts were evaluated every three days by means of a scoring system including opacity, oedema, and vascularization. Time to rejection was analysed with the Kaplan-Meier survival analysis and compared with the log-rank test. The densities of infiltrating immune cells were compared statistically using the non-parametric Mann-Whitney test. RESULTS: Mean rejection-free graft survival was 11.4 days in group 1 (allogeneic control), 100 days (total follow-up time) in group 2 (syngeneic control), 24.0 days in group 3 (MMF 40 mg/kg), 15.7 days in group 4 (FK778 5 mg/kg), 19.1 days in group 5 (FK778 10 mg/kg), and 25.4 days in group 6 (FK778 20 mg/kg) (P<0.005). CONCLUSIONS: Systemic immunosuppression with FK778 prolongs graft survival in the rat keratoplasty model. FK778's efficacy is comparable with that of MMF in preventing immunologic graft rejection.