Protective Effect of Pyrus ussuriensis Maxim. Extract against Ethanol-Induced Gastritis in Rats

Pyrus ussuriensis Maxim (Korean pear) has been used for hundreds of years as a traditional herbal medicine for asthma, cough, and atopic dermatitis in Korea and China. Although it was originally shown to possess anti-inflammatory, antioxidant, and antiatopic properties, its gastroprotective effects have not been investigated. In the present study, we evaluated the protective effects of Pyrus ussuriensis Maxim extract (PUE) against ethanol-induced gastritis in rats. The bioactive compound profile of PUE was determined by gas chromatography mass spectroscopy (GC-MS) and high-performance liquid chromatography (HPLC). The gastroprotection of PUE at different doses (250 and 500 mg/kg body weight) prior to ethanol ingestion was evaluated using an in vivo gastritis rat model. Several endpoints were evaluated, including gastric mucosal lesions, cellular degeneration, intracellular damage, and immunohistochemical localization of leucocyte common antigen. The gastric mucosal injury and ulcer score were determined by evaluating the inflamed gastric mucosa and by histological examination. To identify the mechanisms of gastroprotection by PUE, antisecretory action and plasma prostaglandin E2 (PGE2), gastric mucosal cyclic adenosine monophosphate (cAMP), and histamine levels were measured. PUE exhibited significant antioxidant effects with IC50 values of 56.18 and 22.49 µg/mL for 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′- azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) inhibition (%), respectively. In addition, GC/MS and HPLC analyses revealed several bioactive compounds of PUE. Pretreatment with PUE significantly (P < 0.05) decreased the ulcer index by preventing gastric mucosal lesions, erosion, and cellular degeneration. An immunohistochemical analysis revealed that PUE markedly attenuated leucocyte infiltration in a dose-dependent manner. The enhancement of PGE2 levels and attenuation of cAMP levels along with the inhibition of histamine release following PUE pretreatment was associated with the cytoprotective and healing effects of PUE. In contrast, the downregulation of the H+/K+ ATPase pathway as well as muscarinic receptor (M3R) and histamine receptor (H2R) inhibition was also involved in the gastroprotective effects of PUE; however, the expression of cholecystokinin-2 receptors (CCK2R) was unchanged. Finally, no signs of toxicity were observed following PUE treatment. Based on our results, we conclude that PUE represents an effective therapeutic option to reduce the risk of gastritis and warrants further study.

Morphological and biological characteristics of a pear ( L.) and their importance for the examination of varieties on differences, similarity and stability (DSS)

Целью работы явился анализ результатов исследований морфолого-биологических признаков 5 генотипов груши и их значение при экспертизе сортов на отличимость, однородность и стабильность, как основных критериев признания сорта как такового . В исследованиях использовали «Методику проведения испытаний на отличимость, однородность и стабильность, груша ( Pyrus communis L. и Pyrus ussuriensis Maxim.х Pyrus communis L.)» и документ RTG/01/3 "Общее введение по испытанию на отличимость, однородность и стабильность и составлению описаний" и общепринятая методика сортоизучения плодовых, ягодных и орехоплодных культур. Многолетние исследования морфолого-биологических признаков груши позволили отобрать, среди созданных в Никитском ботаническом саду 5 генотипов груши для введения их в Государственный Реестр охраняемых селекционных достижений. Анализ результатов многолетних исследований морфолого-биологических признаков позволил сделать вывод, что каждый из 5 сортов груши явно отличается от других общеизвестных сортов и соответствует требованиям однородности и стабильности. The aim of the research was to analyze the results of studies of morphological and biological characteristics for 5 pear genotypes and their significance in the variety testing on differences, similarity and stability, as the main criteria of recognition the variety. The “Methodology for testing on differences, similarity and stability, a pear ( Pyrus communis L. and Pyrus ussuriensis Maxim. X Pyrus communis L.)", the document RTG/01/3 "General introduction to the test for differences, similarity and stability and compilation of descriptions" and generally accepted research method of fruit, berry and nut crops were used in this study. Long-term studies of the morphological and biological characteristics of a pear made it possible to select, among the genotypes bred in the Nikitsky Botanical Garden, 5 genotypes of a pear for introduction into the State Register of Protected Breeding Achievements. The analysis of results of long-term studies of morphological and biological characteristics allowed to conclude that each of 5 pear cultivars is clearly different from other well-known varieties and meets the requirements of similarity and stability.

Anti-Inflammatory Effect of Chloroform Fraction of Pyrus Ussuriensis Maxim. Leaf Extract on 2, 4-Dinitrochlorobenzene-Induced Atopic Dermatitis in nc/nga Mice

Pyrus ussuriensis Maxim, a pear commonly known as “Sandolbae” in Korea, is used as a traditional herbal medicine for asthma, cough, and fever in Korea, China, and Japan. P. ussuriensis Maxim leaves (PUL) have therapeutic effects on atopic dermatitis (AD). However, there are no reports on the efficacy of specific components of PUL. In the present study, activity-guided isolation of PUL was used to determine the compounds with potent activity. Astragalin was identified as the major component of the chloroform-soluble fraction of PUL (PULC) using High-performance liquid chromatography (HPLC) analysis. Astragalin and PULC were tested in vitro and in vivo for their effects against AD. PULC and astragalin dose-dependently inhibited the production of nitric oxide (NO) in mouse macrophage (RAW 264.7) cells, and interleukin (IL)-6 and IL-1β in tumor necrosis factor (TNF-α)/interferon γ (IFNγ) induced HaCaT cells. In the AD mice model, PULC and astragalin application significantly reduced dermatitis severity, scratching behavior, and trans-epidermal water loss (TEWL) when compared to that of 2, 4-dinitrochlorobenzene-treated NC/Nga mice. Additionally, they normalized skin barrier function by decreasing immunoglobulin E (IgE) levels in the serum. Filaggrin and involucrin protein levels were normalized by PULC treatment in HaCaT cells and skin lesions. These results indicate that PULC and astragalin ameliorate AD-like symptoms by alleviating both pro-inflammatory cytokines and immune stimuli in vitro and in vivo in animal models. Therefore, PULC and astragalin might be effective therapeutic agents for the treatment of AD.