Scope: Urolithin A is an anti-inflammatory and neuroprotective gut-derived metabolite from ellagitannins and ellagic acid in pomegranate, berries, and nuts. The roles of SIRT-1 and autophagy in the neuroprotective activity of urolithin A are investigated. Methods and results: Analyses of culture supernatants from lipopolysaccharide-stimulated BV2 microglia show that urolithin A (2.5-10 µm) produced significant reduction in the production of nitrite, tumor necrosis factor (TNF)-α and IL-6. The anti-inflammatory effect of the compound is reversed in the presence of sirtuin (SIRT)-1 and the autophagy inhibitors EX527 and chloroquine, respectively. Protein analyses reveal reduction in p65 and acetyl-p65 protein. Treatment of BV2 microglia with urolithin A results in increased SIRT-1 activity and nuclear protein, while induction of autophagy by the compound is demonstrated using autophagy fluorescent and autophagy LC3 HiBiT reporter assays. Viability assays reveal that urolithin A produces a neuroprotective effect in APPSwe-transfectedReNcell VM human neural cells, which is reversed in the presence of EX527 and chloroquine. Increase in both SIRT-1 and autophagic activities are also detected in these cells following treatment with urolithin A. Conclusions: It has been proposed that SIRT-1 activation and induction of autophagy are involved in the neuroprotective activity of urolithin A in brain cells.

Neuroinflammation is now widely accepted as an important pathophysiological mechanism in neurodegenerative disorders, thus providing a critical target for novel compounds. In this study, 3-O-[(E)-(2-oxo-4-(p-tolyl) but 3 en 1 yl] kaempferol (OTBK) prevented the production of pro-inflammatory mediators TNFα, IL-6, PGE2 and nitrite from BV-2 microglia activated with LPS and IFN. These effects were accompanied by a reduction in the levels of pro-inflammatory proteins COX-2 and iNOS. Involvement of NF-B in the anti-inflammatory activity of OTBK was evaluated in experiments showing that the compound prevented phosphorylation, nuclear accumulation and DNA binding of p65 sub-unit induced by stimulation of BV-2 microglia with LPS and IFN. Exposure of mouse hippocampal HT22 neurons to conditioned media from LPS + IFN-stimulated BV-2 cells resulted in reduced cell viability and generation of cellular reactive oxygen species. Interestingly, conditioned media from LPS/IFN-stimulated BV-2 cells which were treated with OTBK did not induce neuronal damage or oxidative stress. OTBK was shown to increase protein levels of phospho-AMPKα, Nrf2 and HO-1 in BV-2 microglia. It was further revealed that OTBK treatment increased Nrf2 DNA binding in BV-2 microglia. The actions of the compound on AMPKα and Nrf2 were shown to contribute to its anti-inflammatory activity as demonstrated by diminished activity in the presence of the AMPK antagonist dorsomorphin and Nrf2 inhibitor trigonelline. These results suggest that OTBK inhibits neuroinflammation through mechanisms that may involve activation of AMPKα and Nrf2 in BV-2 microglia.

Objectives The effects of a root extract of Zanthoxylum zanthoxyloides on neuroinflammation in BV-2 microglia stimulated with LPS and hemozoin were investigated. Methods ELISA, enzyme immunoassay and Griess assay were used to evaluate levels of cytokines, PGE2 and NO in culture supernatants, respectively. Microglia-mediated neurotoxicity was evaluated using a BV-2 microglia-HT-22 neuron transwell co-culture. Key findings Treatment with Z. zanthoxyloides caused reduced elevated levels of TNFα, IL-6, IL-1β, NO and PGE2, while increasing the levels of IL-10. In addition, there were reduced levels of iNOS and COX-2 proteins. This was accompanied by a prevention of microglia-mediated damage to HT-22 mouse hippocampal neurons. Z. zanthoxyloides reduced elevated levels of phospho-IκB and phospho-p65, while preventing degradation of IκB protein and DNA binding of p65. Further mechanistic studies revealed that Z. zanthoxyloides reduced the levels of pro-IL-1β and IL-1β in hemozoin-activated BV-2 microglia. This was accompanied by a reduction in caspase-1 activity and NLRP3 protein expression. Bioassay-guided fractionation resulted in the isolation of skimmianine as an anti-inflammatory compound in Z. zanthoxyloides. Conclusion This is the first report showing the inhibition of neuroinflammation in LPS- and hemozoin-activated BV-2 microglia by the root extract of Z. zanthoxyloides by targeting the activation of both NF-κB and NLRP3 inflammasome.

ObjectivesConcurrent use of herbs with drugs have become a major healthcare problem. Herb-drug interactions could lead to therapeutic failure or toxicity. Hence, this study seeks to evaluate the impact of combining Curcuma longa rhizome (CL) with selected anxiolytic and hypnotic drugs.MethodsCL (100, 200 or 400 mg/kg, p.o.) was administered to mice 1 h before subjecting the animals to elevated plus maze (EPM), hole board test (HBT), open field test (OFT) and rotarod test for anxiolytic-like effect as well as hexobarbitone-induced sleeping time (HIST) for hypnotic activity. The involvement of GABAergic and nitrergic systems in CL-induced anxiolytic and hypnotic actions were also evaluated. The effect of concurrent use of CL with midazolam, imipramine, nifedipine, propranolol and carbamazepine were evaluated in anxiolytic-hypnosis models.ResultsThe peak anxiolytic-like effect of CL was obtained at 400 mg/kg in the EPM and hole-board test without affecting muscle coordination in the rotarod test while the peak hypnosis-potentiation was observed at 100 mg/kg. CL-induced anxiolytic-hypnotic-like effects were reversed by the pretreatment of mice with flumazenil or NG-nitro-l-arginine.ConclusionsCurcuma longa possesses anxiolytic and hypnotic effects through its interaction with GABAergic and nitrergic systems. Conversely, co-administration of C. longa with midazolam potentiate barbiturate-induced hypnosis.