Function of proprotein convertase subtilisin/kexin type 9 and its role in central nervous system diseases: An update on clinical evidence.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) has attracted lots of attention in preventing the clearance of plasma low-density lipoprotein cholesterol (LDL-C). PCSK9 inhibitors are developed to primarily reduce the cardiovascular risk by lowering LDL-C level. Recently, a number of pleiotropic extrahepatic functions of PCSK9 beyond the regulation of cholesterol metabolism, particularly its effects on central nervous system (CNS) diseases have been increasingly identified. Emerging clinical evidence have revealed that PCSK9 may play a significant role in neurocognition, depression, Alzheimer's disease, and stroke. The focus of this review is to elucidate the functions of PCSK9 and highlight the effects of PCSK9 in CNS diseases, with the aim of identifying the potential risks that may arise from low PCSK9 level (variant or inhibitor) in the clinical practice.

Protective effects of total flavonoids from Qu Zhi Qiao (fruit of Citrus paradisi cv. Changshanhuyou) on OVA-induced allergic airway inflammation and remodeling through MAPKs and Smad2/3 signaling pathway.

Allergic asthma is one of the inflammatory diseases, which has become a major public health problem. Qu zhi qiao (QZQ), a dry and immature fruit of Citrus paradisi cv. Changshanhuyou, has various flavonoids with pharmacological properties. However, there is a knowledge gap on the pharmacological properties of QZQ on allergic asthma. Therefore, here, we explored the efficacy and mechanism of total flavonoids from QZQ (TFCH) on allergic asthma. We extracted and purified TFCH and conducted animal experiments using an Ovalbumin (OVA)-induced mice model. Bronchoalveolar lavage fluid and Swiss-Giemsa staining were used to count different inflammatory cells in allergic asthma mice. We conducted histopathology and immunohistochemistry to evaluate the changes in the lungs of allergic asthma mice. Moreover, we used ELISA assays to analyze chemokines and inflammatory cytokines. Furthermore, western blot analyses were conducted to elucidate the mechanism of TFCH on allergic asthma. We established that TFCH has anti-inflammatory effects and inhibits airway remodeling, providing a potential therapeutic strategy for allergic asthma.