Although the pathogenesis of diabetic retinopathy (DR) is still insufficiently understood, new evidences indicate ‘retinal inflammation’ as an important player in the pathogenesis of the complication. Accordingly, common sets of upregulated inflammatory cytokines are found in serum, vitreous and aqueous samples obtained from subjects with DR, and these cytokines can have multiple interactions to impact the pathogenesis of the disease. Thus, based on previously published data, we investigated the effects of Palmitoylethanolamide (PEA), an endogenous lipid amide that belongs to the N-acylethanolamines family, on DR in streptozotocin (STZ)-induced diabetic rats. PEA (10mg/kg) was administered orally daily starting 3 days after the iv administration of STZ. The rats were killed 15 and 60day later and eyes were enucleated to evaluate, through immunohistochemical analysis, the key inflammatory events involved in the breakdown of blood retinal barrier (BRB). Immunohistochemical analysis confirmed the presence of VEGF, ICAM-1, nitrotyrosine (a marker of peroxynitrite), and tight junctions in the retina of STZ-treated rats. Of interest, the extent of injury was significantly reduced after treatment with PEA. Altogether, this study provides the first evidence that PEA attenuates the degree of inflammation while preserving the blood-retinal barrier in rats with experimental DR.
Palmitoylethanolamide is especially in Italy and the USA at the moment hot for the treatment of glaucoma. We prefer treatment either with the Italian PEA tablets, based on PEA-um or PEA-m, or by administrating the Dutch PEA capsules containing PEA-opt. Dutch capsules do not contain any chemical excipients and are 100% pure in vegetarian capsules.
Advise for use of PEA
Only for these the Dutch and the Italian formulations long term safety and efficacy data gathered under the supervision of MDs are available. And only for these formulations (PEA-um, PEA-m and PEA-opt) there are currently data available proving that after intake PEA levels in the body significantly rise. Such data do not exist for me-too PEA formulations.
Palmitoylethanolamide treatment reduces retinal inflammation in streptozotocin-induced diabetic rats.
Paterniti I, Di Paola R, Campolo M, Siracusa R, Cordaro M, Bruschetta G, Tremolada G, Maestroni A, Bandello F, Esposito E, Zerbini G, Cuzzocrea S.
Eur J Pharmacol. 2015 Dec 15;769:313-23.