Low-Molecular-Weight Oligonol, a Polyphenol Derived from Lychee Fruit, Attenuates Experimental Reflux Esophagitis and HCl/Ethanol-Induced Gastric Ulcer

Abstract

Oligonol, a polyphenol derived from lychee fruit, is produced by an oligomerization process that converts high-molecular-weight polyphenol polymers into low-molecular-weight oligomers. Evidence suggests that oligonol exerts its beneficial effects based on antioxidant and anti-inflammatory properties. This study was the first to investigate the antioxidative and anti-inflammatory effects of oligonol on gastroesophageal inflammatory models: surgically induced acute reflux esophagitis (RE) and gastric ulcer (GU) induced by HCl/ethanol. In the in vitro study, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazolin-6-sulfonic acid) (ABTS) radical scavenging assays were performed to determine the antioxidant activity of oligonol. The experimental groups were each composed of normal, vehicle, and oligonol groups. RE rats and GU mice were treated orally with oligonol (100 mg/kg bw) or distilled water as a vehicle (n = 8 for each group). Oligonol exhibited potent free radical-scavenging capacities for DPPH and ABTS radicals, activities that were similar to those of ascorbic acid. The in vivo study revealed that oligonol consumption significantly prevented RE and GU formation and decreased the gross mucosal injury from oxidative stress. Oligonol decreased the reactive oxygen species levels and elevated levels of both inflammatory mediators and cytokines (p-IκB, NF-κBp65, COX-2, iNOS, TNF-α, and IL-1β) in the RE and GU models. Oligonol had a protective effect against oxidative stress by regulating antioxidant enzyme (superoxide dismutase, catalase, and GPx-1/2) activities in GU mice. Oligonol has potential as a preventive and therapeutic agent for gastroesophageal inflammatory diseases, including RE and GU.

Effectiveness of Vitamin C Solution in Reducing Adverse Reactions Caused by Painless Lugol Chromoendoscopy

“…1, Supplemental Digital Content 1, http:// links.lww.com/JCG/A758). [18][19][20][21][22][23][24][25][26] The results showed that the stimulation of esophageal mucosa by LIS led to an increase in IL-8 levels, but the levels of IL-8 decreased after deiodination with VCS for 3 minutes. We speculated that the mechanism of VCS in reducing the acute adverse reactions caused by LIS involved reduced irritation of the mucosa by rapidly neutralizing iodine, thereby reducing the production of IL-8.…”

Hydroxytyrosol and Its Potential Uses on Intestinal and Gastrointestinal Disease

“…Studies have shown that damage to the mucosa of the esophagus leads to a chronic inflammatory condition, with the release of proinflammatory cytokines and often also the formation of fibrotic tissue in both conditions [ 143 , 144 ]. To date, it has been shown that a balanced diet with a high intake of polyphenols can prevent the development of these disorders [ 145 , 146 , 147 ]. Last year, a double-blinded randomized-controlled trial assessed the efficacy of extracts from O. europaea leaves (rich in bioactive compounds such as HT and tyrosol) in gastrointestinal discomfort, showing a decrease in frequency and intensity of the main symptoms of this disorder, such as abdominal swelling, heartburn, and belching [ 148 ].…”

The Role of Increased Gastric Acid Secretion and Reactive Oxygen Species in the Pathophysiology of Reflux Esophagitis

“…Oxidative stress is defined as an excessive intracellular oxidation due to an imbalance between the production of oxidizing species or reactive oxygen species (ROS) and that of antioxidant systems [16,19]. The equilibrium or redox homeostasis is then disrupted, and the cells become vulnerable to free radical attacks, resulting in oxidative damage to cellular components [20,21].…”