The Potential Neuroprotective Effect of Thymoquinone on Scopolamine-Induced In Vivo Alzheimer's Disease-like Condition: Mechanistic Insights.

BACKGROUND: Alzheimer's disease (AD) is a common neurodegenerative disorder without effective treatment. Thymoquinone (TQ) has demonstrated potential in exhibiting anti-inflammatory, anti-cancer, and antioxidant characteristics. Despite TQ's neuroprotection effect, there is a scarcity of information regarding its application in AD research, and its molecular trajectories remain ambiguous. Thus, the objective of the current investigation was to examine the potential beneficial effects and underlying mechanisms of TQ in scopolamine (SCOP)-induced neuronal injury to mimic AD in vivo model. METHODS: Thirty mice were divided into normal, SCOP, and TQ groups. The Y-maze and pole climbing tests were performed to measure memory and motor performance. Afterwards, histopathological and immunohistochemical examinations were carried out. Furthermore, peroxisome proliferator-activated receptor gamma (PPAR-γ) signaling pathway-related proteins and genes were detected with an emphasis on the role of miR-9. RESULTS: TQ has the potential to ameliorate cognitive deficits observed in SCOP-induced AD-like model, as evidenced by the improvement in behavioral outcomes, histopathological changes, modulation of the expression pattern of PPAR-γ downstream targets with a significant decrease in the deposition of amyloid beta (Aß). CONCLUSIONS: TQ provided meaningful multilevel neuroprotection through its anti-inflammatory and its PPAR-γ agonist activity. Consequently, TQ may possess a potential beneficial role against AD development.

Gastrointestinal and hepatic diseases during the COVID-19 pandemic: Manifestations, mechanism and management.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is considered the causative pathogen of coronavirus disease 2019 (COVID-19) and has become an international danger to human health. Although respiratory transmission and symptoms are still the essential manifestations of COVID-19, the digestive system could be an unconventional or supplementary route for COVID-19 to be transmitted and manifested, most likely due to the presence of angiotensin-converting enzyme 2 (ACE2) in the gastrointestinal tract. In addition, SARS-CoV-2 can trigger hepatic injury via direct binding to the ACE2 receptor in cholangiocytes, antibody-dependent enhancement of infection, systemic inflammatory response syndrome, inflammatory cytokine storms, ischemia/reperfusion injury, and adverse events of treatment drugs. Gastrointestinal symptoms, including anorexia, nausea, vomiting, and diarrhea, which are unusual in patients with COVID-19, and some digestive signs may occur without other respiratory symptoms. Furthermore, SARS-CoV-2 can be found in infected patients' stool, demonstrating the likelihood of transmission through the fecal-oral route. In addition, liver function should be monitored during COVID-19, particularly in more severe cases. This review summarizes the evidence for extra-pulmonary manifestations, mechanisms, and management of COVID-19, particularly those related to the gastrointestinal tract and liver.

The interrupted cross-talk of inflammatory and oxidative stress trajectories signifies the effect of artesunate against hepatic ischemia/reperfusion-induced inflammasomopathy.

The antimalarial drug artesunate (Art) has proven its beneficial effects against ischemia/reperfusion (I/R) injury in diverse organs, but its potential role against hepatic I/R is still obscure. This study, hence, examined whether treatment with Art alone or in combination with rapamycin (Rapa), an mTOR inhibitor, can ameliorate hepatic I/R injury via targeting the NLRP3 inflammasome signaling pathway. Rats were divided into hepatic sham- and I/R-operated rats. The latter were either left untreated (I/R group) or treated with Art, Rapa, or their combination. On the molecular level, all treatment regimens succeeded to hinder inflammasome assembly and activation, assessed as NLRP3, ASC, cleaved caspase-1, caspase-11, N-terminal cleaved gasdermin-D (GSDMD-N), IL-1ß, and IL-18. This effect was associated by the inhibition in the harmful signaling pathways HMGB1/RAGE and TLR4/MyD88/TRAF6 to inactivate the transcription factor NF-κB and the production of its pro-inflammatory cytokines IL-1ß, IL-18, IL-6, and TNF-α. Additionally, this effect entailed the inhibition of ICAM-1/MPO/ROS cascade, which in turn hampered cell demise induced by apoptosis, manifested as correction of the imbalanced Bcl2/Bax, as well as pyroptosis (LDH, cleaved caspase-1, caspase-11, GSDMD-N, IL-1ß, and IL-18), and necrosis. The corrected pathways were reflected on the improved liver function (serum ALT, AST, and LDH) and microscopical hepatic architecture. Noteworthy, the effect of Art on all parameters exceeded significantly that of Rapa and even improved the effect of the latter in the combination group. In conclusion, our results suggest novel roles for Art in abating functional and structural I/R-induced hepatic abnormalities via several traversing cross-talking pathways that succeeded to abate NLRP3 inflammasome and cell death.

Combination of Sitagliptin and Silymarin ameliorates liver fibrosis induced by carbon tetrachloride in rats.

Liver fibrosis is a common pathological condition that occurs in most conditions associated with chronic liver injury. Silymarin is a herbal product widely used for its hepatoprotective effect. Sitagliptin, a dipeptidyl peptidase-4 inhibitor (DPP4-I), is clinically used as an oral antidiabetic agent. This study was designed to investigate the effects of Sitagliptin, Silymarin, and their combination on established liver fibrosis in carbon tetrachloride (CCl4) rat model. Male albino rats received intraperitoneal injections of CCl4 three times a week for 7 weeks, as well as daily oral treatments of Sitagliptin (100mg/kg) or Silymarin (100mg/kg) or their combination during the 7 weeks of intoxication. Hepatic fibrotic changes were evaluated by measuring hepatic enzymes (ALT, AST, ALP, and GGT) and markers of fibrosis (transforming growth factor ß1 (TGF-ß1), tissue 4-hydroxyproline level, histopathological score), oxidative stress (MDA, GSH, and NOx levels), inflammation (interleukin-6) as well as markers of HSCs activation (α-smooth muscle actin (α-SMA) expression). The injected rats with CCl4 for 7 weeks resulted in a marked elevation of hepatic fibrotic changes and reduction of GSH level, while the combination therapy showed a significant decrease in the former one and a significant increase in the later. In conclusion, this study shows that the combination therapy is more beneficial than monotherapy in ameliorating liver fibrosis in rats. Our findings suggest that Sitagliptin alone or in combination with Silymarin may introduce a new strategy for treating liver fibrosis in humans.