Tetramethylpyrazine prevents liver fibrotic injury in mice by targeting hepatocyte-derived and mitochondrial DNA-enriched extracellular vesicles.

Liver fibrosis is the common consequence of almost all liver diseases and has become an urgent clinical problem without efficient therapies. Recent evidence has shown that hepatocytes-derived extracellular vesicles (EVs) play important roles in liver pathophysiology, but little is known about the role of damaged hepatocytes-derived EVs in hepatic stellate cell (HSC) activation and following fibrosis. Tetramethylpyrazine (TMP) from Ligusticum wallichii Franchat exhibits a broad spectrum of biological activities including liver protection. In this study, we investigated whether TMP exerted liver-protective action through regulating EV-dependent intercellular communication between hepatocytes and HSCs. Chronic liver injury was induced in mice by CCl4 (1.6 mg/kg, i.g.) twice a week for 8 weeks. In the last 4 weeks of CCl4 administration, mice were given TMP (40, 80, 160 mg·kg-1·d-1, i.g.). Acute liver injury was induced in mice by injection of a single dose of CCl4 (0.8 mg/kg, i.p.). After injection, mice were treated with TMP (80 mg/kg) every 24 h. We showed that TMP treatment dramatically ameliorated CCl4-induced oxidative stress and hepatic inflammation as well as acute or chronic liver fibrosis. In cultured mouse primary hepatocytes (MPHs), treatment with CCl4 or acetaminophen resulted in mitochondrial dysfunction, release of mitochondrial DNA (mtDNA) from injured hepatocytes to adjacent hepatocytes and HSCs through EVs, mediating hepatocyte damage and fibrogenic responses in activated HSCs; pretreatment of MPHs with TMP (25 µM) prevented all these pathological effects. Transplanted serum EVs from TMP-treated mice prevented both initiation and progression of liver fibrosis caused by CCl4. Taken together, this study unravels the complex mechanisms underlying the protective effects of TMP against mtDNA-containing EV-mediated hepatocyte injury and HSC activation during liver injury, and provides critical evidence inspiring the development of TMP-based innovative therapeutic agents for the treatment of liver fibrosis.

Ferulic Acid Ameliorates Hepatic Inflammation and Fibrotic Liver Injury by Inhibiting PTP1B Activity and Subsequent Promoting AMPK Phosphorylation.

Chronic inflammation in response to persistent exogenous stimuli or damage results in liver fibrosis, which subsequently progresses into malignant liver diseases with high morbidity and mortality. Ferulic acid (FA) is a phenolic acid widely isolated from abundant plants and exhibits multiple biological activities including anti-oxidant, anti-inflammation and enhancement of immune responses. Adenosine monophosphate-activated protein kinase (AMPK) functions as a critical energy sensor and is regulated through the phosphorylation of liver kinases like LKB1 or dephosphorylation by protein tyrosine phosphatases (PTPs). However, the role of FA in carbon tetrachloride (CCl4)-induced chronic inflammation and liver fibrosis and AMPK activation has not been elucidated. Here we reported that FA ameliorated CCl4-induced inflammation and fibrotic liver damage in mice as indicated by reduced levels of serum liver function enzyme activities and decreased expression of genes and proteins associated with fibrogenesis. Additionally, FA inhibited hepatic oxidative stress, macrophage activation and HSC activation via AMPK phosphorylation in different liver cells. Mechanically, without the participation of LKB1, FA-induced anti-inflammatory and anti-fibrotic effects were abrogated by a specific AMPK inhibitor, compound C. Combining with the results of molecular docking, surface plasmon resonance and co-immunoprecipitation assays, we further demonstrated that FA directly bound to and inhibited PTP1B, an enzyme responsible for dephosphorylating key protein kinases, and eventually leading to the phosphorylation of AMPK. In summary, our results indicated that FA alleviated oxidative stress, hepatic inflammation and fibrotic response in livers through PTP1B-AMPK signaling pathways. Taken together, we provide novel insights into the potential of FA as a natural product-derived therapeutic agent for the treatment of fibrotic liver injury.

Resveratrol extracted from Chinese herbal medicines: A novel therapeutic strategy for lung diseases.

Lung diseases and their related complications represent a critical source of morbidity and mortality globally and have become a research focus in recent years. There are plenty of hazards that threaten the health of lung by exposure to external environmental stimuli, such as dust, cigarette smoke, PM2.5, air pollution and pathogen infection. These risks lead to the impairment of lung function and subsequent lung diseases including pneumonia, chronic obstructive pulmonary disease (COPD), asthma and idiopathic pulmonary fibrosis (IPF). Compared with antibiotics and corticosteroids therapies, traditional Chinese medicine prescriptions are more effective with fewer side effects. A considerable variety of bioactive ingredients have been extracted and identified from Chinese herbal medicines and are used for the treatment of different lung diseases, including resveratrol. Increasing studies have reported promising therapeutic effects of resveratrol against lung diseases by inhibiting oxidative stress, inflammation, aging, fibrosis and cancer both in vitro and in vivo. In this review, the recent progress in the studies of lung-protective effects and underlying mechanisms of resveratrol and also highlight the potency of resveratrol and traditional Chinese prescriptions containing resveratrol as promising therapeutic options were summarized for the treatment of lung and respiratory diseases.