(Z)-6-6--7-3-a-Diligustilide and Disease-Models--Animal

Alzheimer's disease (AD) is a neurodegenerative disease characterized by β-amyloid (Aβ) protein deposition, neurofibrillary tangle (NFT) formation, and neuronal loss in the brain. The current study was designed to investigate the potential mechanisms by which levistolide A affects the pathogenesis of AD in an amyloid precursor protein/presenilin 1 (APP/PS1) transgenic (Tg) mouse model of AD and N2a/APP695swe cells. Specifically, behavioral changes in levistolide A-treated APP/PS1 Tg mice were assessed by the nest-building and Morris water maze (MWM) tests. Levistolide A treatment clearly ameliorated memory deficits and cognitive decline in APP/PS1 Tg mice. Aβ generation and the inflammatory response in APP/PS1 Tg mouse brains were clearly reduced after long-term levistolide A application. Mechanistically, levistolide A concurrently stimulated the expression of α-secretase and decreased the generation of β- and γ-secretases. In addition, levistolide A inhibited the phosphorylation of tau in the brains of the Tg mice. Furthermore, in vitro and in vivo experiments suggested that peroxisome proliferator-activated receptor γ (PPARγ) is the key transcription factor that mediates the regulatory effects of levistolide A on the expression of α-, β-, and γ-secretases and phosphorylation of tau. Collectively, these findings show that levistolide A may be a candidate for the treatment of AD.

Topics: Alzheimer Disease; Amyloid beta-Protein Precursor; Animals; Benzofurans; Blotting, Western; Brain; Cognitive Dysfunction; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Female; Fluorescent Antibody Technique; Mice; Mice, Transgenic; Morris Water Maze Test; Nootropic Agents; PPAR gamma; Presenilin-1; Signal Transduction

The renin angiotensin system (RAS) serves an important role in the development of hepatic fibrosis. Therefore, the present study investigated the effect of levistilide A (Lev A) on hepatic fibrosis via regulation of RAS. The effects of Lev A on the proliferation and activation of hepatic stellate cells (HSCs) were measured using a 5‑ethynyl‑2'‑deoxyuridine assay, western blot analysis and immunofluorescence. The in vivo anti‑hepatic fibrosis effect of Lev A was examined using a CCL4‑induced rat fibrosis model. Lev A significantly prohibited angiotensin (Ang) II‑induced proliferation of HSCs, and overexpression of smooth muscle α‑actin (α‑SMA) and F‑actin in HSCs. Lev A partly reversed Ang II‑induced angiotensin type 1 receptor (AT1R) upregulation and ERK and c‑Jun phosphorylation. In CCL4‑induced hepatic fibrosis rats, Lev A treatment significantly decreased the expression of collagen, α‑SMA and hydroxyproline in rat liver, and improved liver functions. Lev A treatment also significantly inhibited the CCL4‑induced increase in plasma Ang II, and upregulation of AT1R and phosphorylated ERK in rat liver. In conclusion, Lev A is a potential agent for the treatment of hepatic fibrosis by suppressing Ang II/AT1R/ERK/c‑Jun activation in HSCs.

Topics: Actins; Angiotensin II; Animals; Carbon Tetrachloride; Cell Proliferation; Cell Survival; Cells, Cultured; Disease Models, Animal; Hepatic Stellate Cells; Heterocyclic Compounds, Bridged-Ring; Liver Cirrhosis; Male; Rats; Receptor, Angiotensin, Type 1; Signal Transduction; Up-Regulation