Astragaloside IV Ameliorates Cognitive Impairment and Neuroinflammation in an Oligomeric Aß Induced Alzheimer's Disease Mouse Model via Inhibition of Microglial Activation and NADPH Oxidase Expression.

Microglial activation and neuroinflammation induced by amyloid ß (Aß) play pivotal roles in Alzheimer's disease (AD) pathogenesis. Astragaloside IV (AS-IV) is one of the major active compounds of the traditional Chinese medicine Astmgali Radix. It has been reported that AS-IV could protect against Aß-induced neuroinflammation and cognitive impairment, but the underlying mechanisms need to be further clarified. In this study, the therapeutic effects of AS-IV were investigated in an oligomeric Aß (oAß) induced AD mice model. The effects of AS-IV on microglial activation, neuronal damage and reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase expression were further studied. Different doses of AS-IV were administered intragastrically once a day after intracerebroventricularly oAß injection. Results of behavioral experiments including novel object recognition (NOR) test and Morris water maze (MWM) test revealed that AS-IV administration could significantly ameliorate oAß-induced cognitive impairment in a dose dependent manner. Enzyme linked immunosorbent assay (ELISA) results showed that increased levels of reactive oxygen species (ROS), tumor necrosis factor α (TNF-α), interleukin-1ß (IL-1ß) and IL-6 in hippocampal tissues induced by oAß injection were remarkably inhibited after AS-IV treatment. OAß induced microglial activation and neuronal damage was significantly suppressed in AS-IV-treated mice brain, observed in immunohistochemistry results. Furthermore, oAß upregulated protein expression of NADPH oxidase subunits gp91phox, p47phox, p22phox and p67phox were remarkably reduced by AS-IV in Western blotting assay. These results revealed that AS-IV could ameliorate oAß-induced cognitive impairment, neuroinflammation and neuronal damage, which were possibly mediated by inhibition of microglial activation and down-regulation of NADPH oxidase protein expression. Our findings provide new insights of AS-IV for the treatment of neuroinflammation related diseases such as AD.

Trichodimerol and sorbicillin induced apoptosis of HL-60 cells is mediated by reactive oxygen species.

In this study, two secondary metabolite compounds, trichodimerol and sorbicillin were isolated from the mycelial mass of the marine fungus Trichothecium sp.. It was found that trichodimerol and sorbicillin exhibited strong cytotoxic activity with IC50 values from 6.55 µM to 28.55 µM on three cancer cell lines, HL-60, U937 and T47D. Then HL-60 cells were employed for apoptotic assay. The two compounds could significantly increase the levels of activated caspase-3/7 in a dose-dependent manner and remarkably increase sub-G1 fraction in the cell cycle using flow cytometry, indicating that trichodimerol and sorbicillin potently induced apoptosis in HL-60 cells. Trichodimerol or sorbicillin induced ROS levels also showed dose-dependent increases in HL-60 cells as measured by 2',7'-Dichlorodihydrofluorescein diacetate (DCFH-DA), while trichodimerol or sorbicillin induced apoptosis was effectively blocked by the ROS inhibitor N-acetyl-L-cysteine (NAC). Western blot results showed that trichodimerol or sorbicillin could increase phosphorylated p38 levels and decrease ERK and phosphorylated ERK levels in a concentration-dependent manner. Our findings suggest that the pro-apoptosis effects of trichodimerol and sorbicillin were mediated by ROS, while activation of p38 and inhibition of ERK may be involved in these effects.

A new periplogenin cardenolide from the seeds of Antiaris toxicaria.

A new periplogenin cardenolide, periplogulcoside (1), together with three known cardenolides, was isolated from the seeds of Antiaris toxicaria. The structure of the new compound was characterized as periplogenin-3-O-ß-D-glucopyranosyl-(1 → 4)-ß-D-glucopyranoside (1) by spectroscopic methods including 1D and 2D NMR, HR-TOF-MS, and CD spectrometry, and the known compounds were identified by comparison of their NMR and HR-TOF-MS data with those reported in the literature. Compound 1 showed significant cytotoxicity against Hela and HepG-2 cell lines.