Proanthocyanidins attenuates ferroptosis against influenza-induced acute lung injury in mice by reducing IFN-γ.

BACKGROUND: Acute lung injury (ALI) is associated with high morbidity and mortality and is partly driven promoted by ferroptosis. Proanthocyanidins (PAs) is a natural bioactive flavonoid with anti-inflammatory and antioxidant activities. PAs can also significantly protect against acute lung inflammation and ferroptosis in alveolar epithelial cells. However, it is unclear whether PAs can alleviate ALI by reducing ferroptosis. This study aimed to evaluate the protective effects of PAs and the potential mechanisms against Influenza A virus (IAV)-induced ALI. METHODS: Mice were inoculated nasally with IAV to induce ALI. IAV-induced pulmonary inflammation and ferroptosis was tested by measuring the levels of malondialdehyde (MDA), glutathione (GSH), glutathione peroxidase 4 (GPX4), solute carrier family 7 member 11 (SLC7A11) and acyl-CoA synthetase long-chain family member (ACSL4) in lung tissue. The potential targets that PAs protect against IAV-induced ALI were determined via a systemic pharmacological analysis. The molecular mechanism of PAs in ALI treatment was investigated by assessing the level of inflammation and ferroptosis markers using Western Blot and quantitative real-time PCR. RESULTS: Systemic pharmacological analysis suggested that PAs protect against IAV-induced pneumonia thorough TGF-ß1 and its relative signaling pathway. PAs effectively alleviated histopathological lung injury, reduced inflammatory cytokines and chemokines secretion, which were increased in IAV-infected mice. Meanwhile, PAs further prevented mouse airway inflammation in ALI, concomitant with the decreased expression TGF-ß1, smad2/3, p-Smad2, p-Smad3 and ferroptosis mediator IFN-γ. Furthermore，IFN-γ promotes cell lipid peroxidation and ferroptosis，PAs significantly reduced MDA and ACSL4 levels and upregulated GSH, GPX4, and SLC7A11. CONCLUSION: Overall, PAs can attenuate ferroptosis against IAV-induced ALI via the TGF-ß1/Smad2/3 pathway and is a promising novel therapeutic candidate for ALI.

Carvacrol inhibits the excessive immune response induced by influenza virus A via suppressing viral replication and TLR/RLR pattern recognition.

ETHNOPHARMACOLOGICAL RELEVANCE: Carvacrol, a monoterpene phenol from Mosla chinensis Maxim, which is a commonly Chinese herbal medicine. The most important pharmacology of it is dispelling exogenous evils by increasing perspiration. And it is the gentleman medicine in the Chinese herbal compound prescription of Xin-Jia-Xiang-Ru-Yin, mainly for the treatment of summer colds with dampness including influenza virus A infection. AIM OF THE STUDY: Our preliminary study verified that the Xin-Jia-Xiang-Ru-Yin could inhibit acute lung injury of mice with influenza virus A infection. And there have been some reports implicating the high antimicrobial activity of carvacrol for a wide range of product preservation, but little research including the effects of it on viral infection. The aim of this study was to reveal the antiviral effects of carvacrol, the main constituent in Mosla chinensis Maxim. MATERIALS AND METHODS: Initially, C57BL/6 mice were grouped and intranasally administered FM1 virus to construct viral infection models. After treatment with ribavirin and carvacrol for 5 days, all mice were euthanized, and specimens were immediately obtained. Histology, flow cytometry and Meso Scale Discovery (MSD) analysis were used to analyze pathological changes in lung tissue, the expression levels of cytokines and the differentiation and proportion of CD4+ T cells subsets, while Western blot and qRT-PCR were used to detect the expression of related proteins and mRNA. RESULTS: Carvacrol attenuated lung tissue damage, the proportions of Th1, Th2, Th17 and Treg in CD4+ T cells and the relative proportions of Th1/Th2 and Th17/Treg cells. Carvacrol inhibited the expression of inflammation-associated cytokines including IFN-γ, IL-2, IL-4, IL-5, IL-12 and TNF-ɑ, IL-1, IL-10, IL-6. Decreased levels of TLR7, MyD88, IRAK4, TRAK6, NF-κB, RIG-I, IPS-I and IRF mRNA in carvacrol-treated mice were observed comparing to the mice in VC group. Further, the total expression of RIG-I, MyD88 and NF-κB proteins had increased significantly in the VC group but reduced obviously in the group treated with ribavirin or carvacrol. CONCLUSIONS: These results indicate that carvacrol is a potential alternative treatment for the excessive immune response induced by influenza virus A infection, the cold-fighting effect of Mosla chinensis Maxim may depend on the anti-virus of carvacrol.

Dihydrosanguinarine suppresses pancreatic cancer cells via regulation of mut-p53/WT-p53 and the Ras/Raf/Mek/Erk pathway.

BACKGROUND: There have been some reports implicating the pharmacologic action of Dihydrosanguinarine (DHSA), but little research including the effects of it on cancer cells. PANC-1 cells have mutations in K-Ras and TP53, which respectively express mutant K-Ras and p53 protein, and the mutations in Ras/p53 have been believed with closely relationship to the occurrence of various tumors. PURPOSE: To reveal the inhibition of Dihydrosanguinarine on pancreatic cancer cells (PANC-1 and SW1990) proliferation by inducing G0/G1 and G2/M phase arrest via the downregulation of mut-p53 protein, inducing apoptosis and inhibiting invasiveness through the Ras/Mek/Erk signaling pathway. METHODS: Human pancreatic cancer cell lines were cultured with cisplatin and DHSA. Then, cell proliferation, the cell cycle and apoptosis were measured by CCK-8 and flow cytometry. The migratory and invasive abilities of pancreatic cancer cells were evaluated by transwell assay. The expression levels of mRNA and protein were measured by RT-PCR and western blotting. RESULTS: The results showed that DHSA treatment inhibited cell proliferation, migration and invasion in a time- and dose-dependent manner and led to induction of cell cycle arrest and apoptosis. G0/G1 and G2/M phase arrest inhibited the viability of PANC-1 cells by downregulating the expression of mut-p53 protein. Decreased levels of C-Raf and Erk phosphorylation in DHSA-treated PANC-1 and SW1990 cells were observed in a time- and dose-dependent manner. However, the total expression of p53 and Ras proteins had a different change in PANC-1 and SW1990 cells. CONCLUSIONS: Our findings offer the novel perspective that DHSA inhibits pancreatic cancer cells through a bidirectional regulation between mut-p53/-Ras and WT-p53/-Ras to restore the dynamic balance by Ras and p53 proteins.

Novel hypolipidemic conjugates of fatty acid and bile acid with lysine for linkage.

Novel fatty acid-bile acid conjugates (1a-1k) were designed and synthesized by coupling of the fatty acids to the 3-OH of bile acids using lysine for linkage. In the conjugates, the 24-COOH of the bile acids was kept intact to preserve liver-specific recognition. The ability of the newly synthesized conjugates (at 100 mg/kg dosage) to reduce total cholesterol (TC) and triglyceride (TG) levels in mice fed with high-fat diet (HFD) was evaluated. Conjugates of stearic acid with cholic acid and palmitic acid with ursodeoxycholic acid (at dosages of 50, 100, and 200 mg/kg) were further evaluated to determine their ability to reduce aspartate aminotransferase (AST), alanine aminotransferase (ALT), TC, and TG levels in mice fed with HFD. All conjugates showed potent hypolipidemic activity. Further investigation revealed that compounds 1c and 1 g not only dose-dependently reduced serum levels of TC and TG, but also inhibited the elevation of serum AST and ALT levels in mice fed with HFD. Thus, compounds 1c and 1 g are promising hypolipidemic agents with hepatocyte protective effects against HFD-induced liver damage.

RLA8-A New and Highly Effective Quadruple PPAR-α/γ/δ and GPR40 Agonist to Reverse Nonalcoholic Steatohepatitis and Fibrosis.

Nonalcoholic fatty liver disease (NAFLD) is a very common chronic hepatic disease, with nonalcoholic steatohepatitis (NASH) as a major and severe subcategory that can lead to cirrhosis and hepatocellular carcinoma, and thereby to a high mortality rate. Currently, there has been no approved drug to treat NAFLD or NASH. The current study has presented RLA8, a novel and balanced quadruple agonist for hepatic lipid metabolism and inflammation-related peroxisome proliferator-activated receptors (PPARs)-α/γ/δ and G protein-coupled receptor 40 (GPR40), as a NASH drug candidate. The efficacy of RLA8 to treat NASH was evaluated in vivo using two mouse models induced by methionine/choline-deficient diet or by high-fat diet, respectively. RLA8 was shown to improve serum alanine aminotransferase and high-density lipoprotein cholesterol levels, reduce hepatic free fatty acid and triglyceride levels, and alleviate insulin resistance. Cytokine and lipoperoxide analysis revealed that RLA8 could reduce oxidative stress and inflammation. Histochemical and morphologic examination of mouse livers showed that RLA8 could improve pathologic changes such as steatosis, ballooning, collagen fiber, and inflammation. Polymerase chain reaction and Western blot analyses proved that RLA8 could result in PPARs and GPR40 activation, accompanied by upregulation of the 5'AMP-activated protein kinase-acetyl-CoA carboxylase pathway and inhibition of the expression of lipogenic genes and proteins, which provided more insights into its action mechanisms. In summary, RLA8 has significantly better efficacy to improve NASH-induced liver damage such as steatosis, inflammation, and fibrosis, and, consequently, it represents a new and highly promising NASH drug candidate that is worthy of further investigation and development.