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INTRODUCTION: Kainic Acid (KA) is an ionotropic glutamate receptor agonist. KA can induce neuronal overactivity and excitotoxicity. Rosmarinic Acid (RA) is a natural polyphenolic compound with antioxidant, anti-apoptotic, anti-neurodegenerative, and anti-inflammatory properties. This study aimed to assess the effect of RA on apoptosis, nNOS-positive neurons number, as well as Mitogen-Activated Protein Kinase (MAPK) and Cyclooxygenase-2 (COX-2) immunoreactivity, following intrahippocampal Kainic acid injection in rats. METHODS: The study rats were randomly assigned to three groups of sham, KA (KA was injected into the right side of the hippocampus) and KA+RA (a dose of 10 mg/kg/day through a gavage needle for one week before KA injection). Then, histopathological changes, including apoptosis [Terminal Deoxynucleotidyl Transferase (TdT) dUTP Nick-End Labeling (TUNEL) assay], nNOS-positive neurons number, as well as COX-2 and MAPK immunoreactivity were evaluated in the hippocampus. RESULTS: In the RA pretreated group, nNOS-positive neurons and TUNEL-positive cells were significantly reduced compared to the KA group (P<0.05). COX-2and MAPK immunoreactivity demonstrated no significant changes compared to the KA group. They indicated a significant higher reactivity for COX-2 (P<0.01) and MAPK (P<0.005) versus the sham group. CONCLUSION: RA had neuroprotective effects, compared to KA, through reduced apoptosis and nNOS-positive neurons, but not MAPK and COX-2.

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Airway inflammation and oxidative stress are the two major characteristics of asthma pathogenesis. Therefore, this study evaluated the protective effects of ascorbic acid in combination with calcitriol on the oxidative damages and inflammation in asthma model. All animals, except in the control group, were sensitized and challenged with ovalbumin. One day after the last challenge, samples of bronchoalveolar lavage fluid was collected for the assessment of total white blood cell counts and differential count of white blood cell and plasma was used for the measurement of pro-oxidant/antioxidant balance level. Lung tissue samples were also stored for examining peribronchial inflammatory cell infiltration, phosphorylated nuclear factor-kappa B expression and measurement of malondialdehyde level. Induction of asthma caused significant increases in total white blood cell counts, percentage of neutrophils and eosinophils and a decrease in the percentage of lymphocytes. Moreover, asthma resulted in significant increases of peribronchial inflammatory cell infiltration, phosphorylated nuclear factor-kappa B expression and malondialdehyde level. However, no significant changes were observed in pro-oxidant/antioxidant balance level with the induction of asthma. Co-administration of low doses of ascorbic acid and calcitriol returned all to the levels measured before sensitization and challenge. Combination of low doses of ascorbic acid with calcitriol improves mouse asthma model by a possible additive effects through the decrease of oxidative stress and inflammation.

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Asthma is a chronic inflammatory disease of the lungs driven by T cell activation. Viola tricolor L. as a traditional medical herb could suppress activated T lymphocytes and has been used empirically for asthma remedy. In the present study, we investigated the anti-inflammatory effect of Viola tricolor and its underlying mechanism on asthma characteristics induced by ovalbumin (OVA) in mice. BALB/c mice were randomly divided into six groups: normal control, Ovalbumin (OVA) control, OVA mice treated with Viola tricolor (50, 100 and 200 mg/kg) and dexamethasone (3 mg/kg). All mice except normal controls were sensitized and challenged with OVA. Asthmatic mice were treated orally in the last 7 days of OVA challenge. The total and differential leukocyte counts, Interleukin (IL)-4 and interferon (IFN)-γ levels in bronchoalveolar lavage fluid (BALF) were determined. H and E staining for lung inflammation was performed. Viola tricolor treatment at 200 mg/kg significantly decreased IL-4 level but did not considerably affect the IFN-γ level. Therefore, it effectively reduced asthma characteristics including infiltration of leukocytes particularly eosinophil and peribronchial inflammation as compared to dexamethasone. However, Viola tricolor at 100 mg/kg had the most prominent inhibitory effect on the IL-4 level and also markedly increased IFN-γ level. As result, it prevented further reduction of inflammatory parameters in this group compared to the Viola tricolor-treated group at 200 mg/kg. Our study demonstrated that Viola tricolor has anti-inflammatory effects via inhibition of T-helper type 2 (Th2) cytokine production and validated its empirical usage in traditional medicine.

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