Rebamipide Mitigates Impairments in Mitochondrial Function and Bioenergetics with α-Synuclein Pathology in 6-OHDA-Induced Hemiparkinson's Model in Rats.

Parkinson's disease (PD) is one of the widely reported neurodegenerative disorders affecting more than ten million people worldwide. Due to therapeutic limitations and several adverse effects associated with currently used drugs, it is crucial to search for safe and effective options for treatment of PD. Oxidative stress, mitochondrial dysfunction, α-synuclein oligomeric aggregates, and glucocerebrosidase (GCase) deficiency are involved in PD pathogenesis. Rebamipide, an anti-ulcer drug, is a proven free-radical scavenger and antioxidant. The drug has shown neuroprotective effects in cultured SH-SY5Y cells. Therefore, we investigated the pharmacological effect of rebamipide in 6-hydroxydopamine (6-OHDA)-induced experimental PD model. Rebamipide was given to adult male albino rats of Charles-Foster strain in 20, 40, and 80 mg/kg (R-20, R-40, and R-80) oral dose twice daily for 24 days (day 4 to day 27) after 6-OHDA intrastriatal injection. The drug inhibited 6-OHDA-induced motor deficits and nigral α-synuclein aggregates in dose-dependent manner. R-40 and R-80 dose dependently increased striatal mitochondrial complex I, II, IV, and V activities; mitochondrial bioenergetics; and nigral GCase activity. 6-OHDA-induced lipid peroxidation was decreased. Highest dose (R-80) also decreased apoptotic proteins and upregulated striatal dopamine concentration in 6-OHDA-induced hemiparkinson's rat model. Therefore, the anti-PD effect of rebamipide may involve stabilization of mitochondrial bioenergetics, enhancement of GCase enzymatic activity as well as decreased oxidative stress with α-synuclein pathology, and apoptosis in 6-OHDA-induced hemiparkinson's rat model. Hence, preclinical evidence indicates rebamipide to be a potential drug for management of PD.

Significance of para-esophageal lymph nodes in food or aeroallergen-induced iNKT cell-mediated experimental eosinophilic esophagitis.

Eosinophilic esophagitis (EoE) is a recently recognized inflammatory disorder driven by food hypersensitivity; however, the specific foods and mechanisms involved are unclear. In patients with EoE, we have found that hypersensitivities to corn and peanuts are the most common. Accordingly, we sensitized and exposed mice either intranasally or intragastrically with corn or peanut extract or saline. Esophageal eosinophilia, the genes of eosinophil-directed cytokines, and allergen-induced antibodies were examined in mice challenged with corn or peanut extract or saline. A high number of esophageal lamina propria eosinophils as well as eosinophilic microabscesses, intraepithelial eosinophils, extracellular eosinophilic granules, thickened and disrupted epithelial mucosa, and mast cell hyperplasia were observed in the esophagus of peanut or corn allergen-challenged mice. Mechanistic analysis indicated that para-esophageal lymph nodes might be critical in the trafficking of eosinophils to the esophagus and in EoE association to airway eosinophilia. Furthermore, experimentation with gene-targeted mice revealed that peanut allergen-induced EoE was dependent on eotaxin and invariant natural killer T (iNKT) cells, as CD1d and eotaxin-1/2 gene-deficient mice were protected from disease induction. Thus we provide evidence that para-esophageal lymph nodes are involved in food- or aeroallergen-induced eosinophilia and patchy EoE pathogenesis, likely a mechanism dependent on eotaxins and iNKT cells.