Reverse charge transfer and decomposition in Ca-Te compounds under high pressure.

Pressure alters the nature of chemical bonds and triggers novel reactions. Here, we employed first-principles calculations combined with the CALYPSO structural search technique to reveal the charge transfer reversal between Ca and Te under high pressure in the calcium-tellurium compound (CaxTe1-x, x = 1/4, 1/3, 1/2, 2/3). We predict several new phases with conventional and unconventional compounds and found an unfamiliar phenomenon: the Ca-Te compounds will reverse charge transfer between Ca and Te atoms and decompose into elemental solids under pressure. The Bader charge analyses indicate that the Ca2+ ion gains electrons and becomes an anion under high pressure. This leads to a weakened electrostatic interaction between Ca and Te and ultimately results in decomposition. The calculated band occupation number suggests that the occupation of Ca 3d orbitals under high pressure corresponds to this atypical phenomenon. Our results demonstrated the reverse charge transfer between Ca and Te and, in addition, clarified the mechanism of CaxTe1-x decomposition into solid Ca and Te elements under high pressure, providing important insights into the evolution of the properties of alkaline-earth chalcogenide compounds under high pressure.

Astragalus polysaccharide alleviates alcoholic-induced hepatic fibrosis by inhibiting polymerase I and transcript release factor and the TLR4/JNK/NF-κB/MyD88 pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Astragali Radix (AR), the root of Astragalus membranaceus (Fisch.) Bge. or Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao, known as Huangqi in traditional Chinese medicine, has been widely used in traditional Chinese medicine prescriptions for acute and chronic liver injury. AR was the most important medicine in a Chinese traditional prescription called Huangqi Decoction (HQD), has been used to treat chronic liver diseases since the 11th century. In particular, its major active ingredient, Astragalus polysaccharide (APS), has demonstrated promising effects on inhibiting hepatic fibrosis. However, to date, the effect of APS against alcohol-induced hepatic fibrosis and its underlying molecular mechanisms remains unknown. AIMS OF THE STUDY: This study aimed to explore the effect and potential molecular mechanisms of APS against alcohol-induced hepatic fibrosis by using network pharmacology and experimental validation. MATERIALS AND METHODS: The potential targets and underling mechanism of AR in alcoholic liver fibrosis were first predicted using network pharmacology, followed by experimental validation using SD rat model with alcohol-induced hepatic fibrosis. Further, the predicted candidate signaling pathways and potential target polymerase I and transcript release factor (PTRF) were combined to explore the multifaceted mechanism of APS against alcohol-induced hepatic fibrosis. Finally, overexpression of PTRF was explored to reveal the role of PTRF in the mechanism of APS against alcohol-induced hepatic fibrosis. RESULT: APS exerted potent anti-hepatic fibrosis effects by downregulating genes involved in the Toll-like receptor 4 (TLR4)/JNK/NF-κB/MyD88 pathway. Notably, APS treatment ameliorated the hepatic damage by inhibiting the overexpression of PTRF and decreasing the co-localisation of TLR4/PTRF. Overexpression of PTRF induced reversal of the protective effects of APS on alcohol-induced hepatic fibrosis. CONCLUSION: This study indicated that APS may alleviate alcohol-induced hepatic fibrosis by inhibiting the activation of PTRF and TLR4/JNK/NF-κB/MyD88 pathway, which provides a scientific elucidation for the mechanisms of APS on the anti-hepatic fibrosis activity and presents a promising therapeutic approach for treating hepatic fibrosis.