PEA and luteolin synergistically reduce mast cell-mediated toxicity and elicit neuroprotection in cell-based models of brain ischemia

Abstract

a b s t r a c tThe combination of palmitoylethanolamide (PEA), an endogenous fatty acid amide belonging to the family of the N-acylethanolamines, and the flavonoid luteolin has been found to exert neuroprotective activities in a variety of mouse models of neurological disorders, including brain ischemia. Indirect findings suggest that the two molecules can reduce the activation of mastocytes in brain ischemia, thus modulating crucial cells that trigger the inflammatory cascade. Though, no evidence exists about a direct effect of PEA and luteolin on mast cells in experimental models of brain ischemia, either used separately or in combination. In order to fill this gap, we developed a novel cell-based model of severe brain ischemia consisting of primary mouse cortical neurons and cloned mast cells derived from mouse fetal liver (MC/9 cells) subjected to oxygen and glucose deprivation (OGD).OGD exposure promoted both mast cell degranulation and the release of lactate dehydrogenase (LDH) in a time-dependent fashion. MC/9 cells exacerbated neuronal damage in neuron-mast cells co-cultures exposed to OGD. Likewise, the conditioned medium derived from OGD-exposed MC/9 cells induced significant neurotoxicity in control primary neurons. PEA and luteolin pre-treatment synergistically prevented the OGD-induced degranulation of mast cells and reduced the neurotoxic potential of MC/9 cells conditioned medium. Finally, the association of the two drugs promoted a direct synergistic neuroprotection even in pure cortical neurons exposed to OGD.In summary, our results indicate that mast cells release neurotoxic factors upon OGD-induced activation. The association PEA-luteolin actively reduces mast cell-mediated neurotoxicity as well as pure neurons susceptibility to OGD.

A Polyphenol-Enriched Supplement Exerts Potent Epigenetic-Protective Activity in a Cell-Based Model of Brain Ischemia

“…Primary cultures of mouse cortical neurons were prepared from 15-day-old embryonic C57Bl/6 mice (Charles River, Calco, Italy) and maintained in culture as previously described [23,24]. All animal studies were approved by the Animal Research Committees of the University of Brescia and followed Directive 2010/63/EU of the European Parliament and of the Council of 22 September 2010 on the protection of animals used for scientific purposes.…”

“…OGD was carried out at DIV 11, as previously described [23,24]. Briefly, cells were incubated with deoxygenated glucose-free balanced salt solution and transferred to an air-tight chamber fluxed with 95% N 2 and 5% CO 2 for 10 min to reach an oxygen concentration lower than 0.4%.…”

The Role of Mast Cells in Stroke

“…Different preclinical studies point out a role of MCs in the pathogenesis of ischemic stroke [81,82]. In a cellular model of ischemic stroke, exposure to oxygen and glucose deprivation (OGD) induced mastocytic activation in a fashion dependent on the anoxic insult duration [83,84,85]. MCs exacerbated neuronal damage in neuron–MC cocultures exposed to OGD [83].…”

“…In a cellular model of ischemic stroke, exposure to oxygen and glucose deprivation (OGD) induced mastocytic activation in a fashion dependent on the anoxic insult duration [83,84,85]. MCs exacerbated neuronal damage in neuron–MC cocultures exposed to OGD [83]. Likewise, the conditioned medium derived from OGD-activated MCs induced neurotoxicity in primary neurons [83].…”

Topically Applied Nicotinamide Inhibits Human Hair Follicle Growth Ex Vivo

“…For this purpose, palmitoylethanolamide (PEA) (30 mmol/L), an antipruritic endocannabinoid used in clinical dermatology, was applied to our nicotinamide/PEG6000 formulation (see Supplementary Materials) and applied topically to ex vivo scalp skin ex vivo to reduce MC degranulation (Parrella et al, 2016) (see Supplementary Figure S4 online). The addition of PEA significantly reduced nicotinamide-induced dermal MC degranulation ex vivo (Figure 2i) without altering the hair growth inhibitory effect (Figure 2j).…”