Pachymic acid ameliorates bleomycin-induced pulmonary fibrosis through inhibiting endoplasmic reticulum stress in rats.

The effect of pachymic acid (PA) on pulmonary fibrosis in rats was expected to be investigated in this study. Firstly, bleomycin (BLM) was used to establish pulmonary fibrosis rat model, then PA (10, 20, or 40 mg/kg) was intragastrically administered to the rats for 14 days. Subsequently, a variety of tests was performed to observe changes in sample tissues after different treatments. Briefly, the degree of pulmonary edema in rats was assessed through dry/wet weight ratio. Hematoxylin and eosin (H&E) staining and Masson's trichrome staining were used to observe the pathological injury and fibrosis of lung tissue. Biochemical kits were applied to measure the levels of hydroxyproline (Hyp), transforming growth factor beta-1 (TGFß-1), malondialdehyde (MDA), reactive oxygen species (ROS), and adenosine triphosphate (ATP) and the activities of superoxide dismutase (SOD) and catalase (CAT) in rat lung tissues of each group. The mitochondrial DNA (mtDNA) copy number in rat lung tissue was tested using qRT-PCR. Additionally, the western blot was employed to detect the expression levels of pulmonary fibrosis-related proteins and endoplasmic reticulum (ER) stress-related proteins in each group of rat lung tissue. By virtue of experimental verification above, PA was discovered to alleviate BLM-induced pulmonary edema, pulmonary fibrosis and histopathological damage. On the one hand, PA treatment decreased Hyp and TGF-ß1 levels and down-regulated pulmonary fibrosis-related protein expression [collagen I, α-smooth muscle actin (α-SMA), and fibronectin] in the lung tissue of BLM rats. On the other hand, it significantly increased the levels of SOD, CAT and ATP while decreased the activities of MDA and ROS in BLM rat lung tissues. In addition, the expression levels of ER stress-related proteins [glucose-regulated protein 78 (GRP78), C/EBP homologous protein (CHOP), Caspase 9, and activating transcription factor 4 (ATF4)] were significantly down-regulated in the lung tissue of BLM rats after PA treatment. Collectively, PA may ameliorate BLM-induced pulmonary fibrosis and histopathological damage in rats through inhibiting ER stress and improving mitochondrial function.

Pachymic acid inhibits inflammation and cell apoptosis in lipopolysaccharide (LPS)-induced rat model with pneumonia by regulating NF-κB and MAPK pathways.

Pneumonia is a common infectious disease with high morbidity and mortality. It is caused by a variety of pathogenic microorganisms that infect the lung parenchyma. Anti-infective drugs are one of the preferred choices for the treatment of pneumonia. Pachymic acid (PA) is a lanolin triterpene compound from Poria cocos, which has antiemetic, anti-inflamma-tory, and anticancer properties. Although PA inhibits inflammatory response in a variety of diseases, its role in pneumonia is not clear. In this study, we established that PA improved histopathological changes in the lungs of rats with pneumonia. PA inhibited the expression of inflammatory cytokines in the serum of rats having pneumonia. In addition, PA inhibited the apoptosis of cells from rat lung tissues. Mechanically, PA inhibited inflammation and cell apoptosis via NF-κB and MAPK pathways. Therefore, PA could serve as a promising drug for treating pneumonia.

Pachymic Acid Enhances Pentobarbital-Induced Sleeping Behaviors via GABAA-ergic Systems in Mice.

This study was investigated to know whether pachymic acid (PA), one of the predominant triterpenoids in Poria cocos (Hoelen) has the sedative-hypnotic effects, and underlying mechanisms are mediated via γ-aminobutyric acid (GABA)-ergic systems. Oral administration of PA markedly suppressed locomotion activity in mice. This compound also prolonged sleeping time, and reduced sleep latency showing synergic effects with muscimol (0.2 mg/kg) in shortening sleep onset and enhancing sleep time induced by pentobarbital, both at the hypnotic (40 mg/kg) and sub-hypnotic (28 mg/kg) doses. Additionally, PA elevated intracellular chloride levels in hypothalamic primary cultured neuronal cells of rats. Moreover, Western blotting quantitative results showed that PA increased the amount of protein level expression of GAD65/67 over a broader range of doses. PA increased α- and ß-subunits protein levels, but decreased γ-subunit protein levels in GABAA receptors. The present experiment provides evidence for the hypnotic effects as PA enhanced pentobarbital-induced sleeping behaviors via GABAA-ergic mechanisms in rodents. Taken together, it is proposed that PA may be useful for the treatment of sleep disturbed subjects with insomnia.