Oxidative stress plays an important role in Parkinson’s disease and other neurodegenerative disorders. Lycium barbarum polysaccharides (LBP), the main active ingredients extracted from the fruits of Lycium barbarum L., have been shown to be a potent antioxidant. In the present study, we investigated the protective effects, and the possible mechanism of action of LBP against 6-hydroxydopamine (6-OHDA)-induced apoptosis in PC12 cells. Our data demonstrated that LBP significantly reversed the 6-OHDA-induced decrease in cell viability, prevented 6-OHDA-induced changes in condensed nuclei and decreased the percentage of apoptotic cells in a dose-dependent manner. Furthermore, LBP also slowed the accumulation of reactive oxygen species (ROS) and nitric oxide (NO), decreased the level of protein-bound 3-nitrotyrosine (3-NT) and intracellular free Ca2+, and inhibiting the overexpression of nuclear factor κB (NF-κB), neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS). These results demonstrate that LBP prevents 6-OHDA-induced apoptosis in PC12 cells, at least in part through the ROS-NO pathway.
Five new alkaloids, daphnicyclidins M and N (compounds 1 and 2) and calyciphyllines Q–S (compounds 3–5), along with four known ones, paxiphylline C (6), macropodumine B (7), macropodumine C (8) and daphnicyclidin A (9) were isolated from the stem bark of Daphniphyllum macropodum. Calyciphylline Q (3) is the first calyciphylline A derivative possessing a double bond between C-18 and C-19. Their structures and relative configurations were elucidated on the basis of spectroscopic methods, especially 2D NMR techniques. Compounds 1, 2, 8 and 9 exhibited cytotoxic activity against P-388 cells with IC50 values of 5.7, 6.5, 10.3 and 13.8 µM, respectively. Compounds 1 and 2 also showed cytotoxic activity against SGC-7901 cells with IC50 values of 22.4 and 25.6 µM.
Liver fibrosis is a commonly observed pathological phenomenon that occurs during the progression of various types of chronic liver diseases. The Hippo pathway is closely associated with the pathogenesis of liver fibrosis. Previous studies have shown that wedelolactone (WED) has a significant antihepatic fibrosis effect, whereas the target and mechanism underlying WED remain elusive. In this study, we found that WED significantly alleviated liver fibrosis and injury by inhibiting the expression of Yes-associated protein (YAP) and tafazzin (TAZ). In an in vitro model, WED suppressed the activation of hepatic stellate cells (HSCs) induced by transforming growth factor (TGF-β1), as well as the mRNA and protein expression of α-smooth muscle actin (α-SMA), YAP, and TAZ. The allosteric regulation of YAP by WED was confirmed using MD and cellular thermal shift assay. Moreover, specific knockdown or inhibition of YAP did not enhance the suppressive effect of WED on HSC activation or protein expression associated with fibrosis. These findings demonstrated that the administration of WED effectively alleviated liver fibrosis by suppressing the Hippo/YAP/TAZ pathways. In addition, YAP activity may be regulated by WED via allosteric regulation.