Inhibiting thrombosis without generating bleeding risks is a major challenge in medicine. A promising solution may be the inhibition of coagulation factor XII (FXII), because its knockout or inhibition in animals reduced thrombosis without causing abnormal bleeding. Herein, we have engineered a macrocyclic peptide inhibitor of activated FXII (FXIIa) with subnanomolar activity (K i = 370 ± 40 pM) and a high stability (t 1/2 > 5 days in plasma), allowing for the preclinical evaluation of a first synthetic FXIIa inhibitor. This 1899 Da molecule, termed FXII900, efficiently blocks FXIIa in mice, rabbits, and pigs. We found that it reduces ferricchloride-induced experimental thrombosis in mice and suppresses blood coagulation in an extracorporeal membrane oxygenation (ECMO) setting in rabbits, all without increasing the bleeding risk. This shows that FXIIa activity is controllable in vivo with a synthetic inhibitor, and that the inhibitor FXII900 is a promising candidate for safe thromboprotection in acute medical conditions.
White, green, and oolong teas are produced from the tea plant (Camellia sinensis (L.) Kuntze) and are reported to have anti-obesity and hypolipidemic effects. The current study aims to investigate the anti-obesity effects of a tea mixture nano-formulation by targeting the AMPK/Sirt-1/GLUT-4 axis in rats. In vitro lipase and α-amylase inhibition assays were used to determine the active sample, which was then incorporated into a nanoparticle formulation subjected to in vivo anti-obesity testing in rats by measuring the expression level of different genes implicated in adipogenesis and inflammation using qRT-PCR. Moreover, metabolomic analysis was performed for each tea extract using LC/ESI MS/MS coupled to chemometrics in an attempt to find a correlation between the constituents of the extracts and their biological activity. The in vitro pancreatic lipase and α-amylase inhibition assays demonstrated more effective activity in the tea mixture than the standards, orlistat and acarbose, respectively, and each tea alone. Thus, the herbal tea mixture and its nanoparticle formulation were evaluated for their in vivo anti-obesity activity. Intriguingly, the tea mixture significantly decreased the serum levels of glucose and triglycerides and increased the mRNA expression of GLUT-4, P-AMPK, Sirt-1, and PPAR-γ, which induce lipolysis while also decreasing the mRNA expression of TNF-α and ADD1/SREBP-1c, thereby inhibiting the inflammation associated with obesity. Our study suggests that the tea mixture nano-formulation is a promising therapeutic agent in the treatment of obesity and may also be beneficial in other metabolic disorders by targeting the AMPK/Sirt-1/Glut-4 pathway.
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