Given a passage, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

Let me give you an example: Chronic rhinosinusitis (CRS) is a heterogeneous disease with an uncertain pathogenesis. Group 2 innate lymphoid cells (ILC2s) represent a recently discovered cell population which has been implicated in driving Th2 inflammation in CRS; however, their relationship with clinical disease characteristics has yet to be investigated. The aim of this study was to identify ILC2s in sinus mucosa in patients with CRS and controls and compare ILC2s across characteristics of disease. A cross-sectional study of patients with CRS undergoing endoscopic sinus surgery was conducted. Sinus mucosal biopsies were obtained during surgery and control tissue from patients undergoing pituitary tumour resection through transphenoidal approach. ILC2s were identified as CD45(+) Lin(-) CD127(+) CD4(-) CD8(-) CRTH2(CD294)(+) CD161(+) cells in single cell suspensions through flow cytometry. ILC2 frequencies, measured as a percentage of CD45(+) cells, were compared across CRS phenotype, endotype, inflammatory CRS subtype and other disease characteristics including blood eosinophils, serum IgE, asthma status and nasal symptom score. 35 patients (40% female, age 48 ± 17 years) including 13 with eosinophilic CRS (eCRS), 13 with non-eCRS and 9 controls were recruited. ILC2 frequencies were associated with the presence of nasal polyps (P = 0.002) as well as high tissue eosinophilia (P = 0.004) and eosinophil-dominant CRS (P = 0.001) (Mann-Whitney U). They were also associated with increased blood eosinophilia (P = 0.005). There were no significant associations found between ILC2s and serum total IgE and allergic disease. In the CRS with nasal polyps (CRSwNP) population, ILC2s were increased in patients with co-existing asthma (P = 0.03). ILC2s were also correlated with worsening nasal symptom score in CRS (P = 0.04).
The answer to this example can be: Are group 2 innate lymphoid cells ( ILC2s ) increased in chronic rhinosinusitis with nasal polyps or eosinophilia?
Here is why: The question is based on the following sentences from the passage (i) Group 2 innate lymphoid cells (ILC2s) {ii) In the CRS with nasal polyps (CRSwNP) population, ILC2s were increased in patients with co-existing asthma (iii) As ILC2s are elevated in patients with CRSwNP, they may drive nasal polyp formation in CRS. and (iv) They were also associated with increased blood eosinophilia

OK. solve this:
Ulcerative colitis (UC) is a chronic inflammatory intestinal disease. It is necessary to find out new effective drugs for UC. In our study epicatechin extracted from grape seed by our institute for the first time could treat UC effectively. Then anti-UC mechanisms of epicatechin were elucidated in vivo and in vitro.', 'Dextran sulfate sodium (DSS)-induced acute UC mice model was used to evaluate the activity of epicatechin and its properties against UC. Then its anti-inflammatory and antioxidant effects were evaluated as follows: the concentrations of TNF-α and IL-6 in the colon supernatants were determined by ELISA. NO and MPO were assayed by Griess method and commercial kit respectively. NF-κB were determined by NF-κB-Dependent Reporter Gene Expression Assay and Western Blotting respectively. Antioxidant factors such as SOD, MDA, GSH-Px and CAT were also measured in colon tissues and cell supernatant stimulated by LPS respectively.', 'In C57BL/6J mice model with DSS-induced UC, epicatechin was able to decrease the disease activity index and colon macroscopic damage index scores, reduce body weight loss, and significantly relieve colon contracture and crypt damage. TNF-α, IL-6, NO, MPO and MDA were reduced in the mice administered epicatechin, whereas antioxidant enzymes showed increased activity in epicatechin-treated mice and cell line respectively. Furthermore, inhibition effect on NF-κB activation by epicatechin were demonstrated in vivo and in vitro.
Answer:
Is the protective effect of epicatechin on experimental ulcerative colitis in mice mediated by increasing antioxidation and by the inhibition of NF-κB pathway?