Protective Effects of Quercetin, a Flavonoid Antioxidant, in Absolute Ethanol-Induced Acut Gastric Ulcer

Abstract

INTRODUCTION Ethanol manifests its harmful effects either through direct generation of reactive metabolites, including free radical species that react with most of the cell components, changing their structures and functions, or by contributing to other mechanisms that finally promote enhanced oxidative damage (1,2). Ethanol-induced gastric mucosal injury is associated with extensive damage to mucosal capillaries and increased vascular permeability (3,4). Mucosal capillary necrosis, vascular congestion and thrombosis in the subepithelial microvasculature accompany disruption of the gastric mucosal barrier. In addition to the direct injurious effects of ethanol on gastric mucosa, other factors are also thought to be involved in the pathogenesis of injury (5). Flavonoids are a group of naturally occurring compounds widely distributed as secondary metabolites in the plant kingdom. They have been recognized for having interesting clinical properties, such as anti-inflammatory, antiallergic, antiviral, antibacterial, and antitumoral activities (6).

Quercetin attenuates, indomethacin-induced acute gastric ulcer in rats

“…Gastric mucosa can be repaired after mucosal injury by mucosal restitution and reepithelisation by sloughing off the damaged cells. This is achieved by rapid migration of viable stem cells to the injured site to replace the dead cells during ulcer healing [13]. However, human studies have failed to show any adverse effects associated with the oral administration of quercetin in a single dose of up to 4 g or after 1 month of 500 mg twice daily [54].…”

Anti-inflammatory Activities and Gastric Ulcer-inducing Properties of Tetraacetylquercetin and Tetrapivaloylquercetin

“…This gastric ulcer-inducing effect is correlated to inhibition of cyclooxygenase-1, which plays a role in gastrointestinal mucous biosynthesis. However, the gastric ulcer toxicity of TAQ was lower than that of diclofenac, which showed severe gastric ulcer toxicity due to the gastric ulcer protecting effect of quercetin [5].…”

“…Quercetin has also been reported to promote antioxidant enzyme activity, prevent free radical attacks as well as enhance endogenous antioxidant molecules [1]. In addition, quercetin possesses gastric protective and gastric ulcer healing-promoting action [5], so quercetin was chosen as lead compound for the development of anti-inflammatory agents with low-risk of gastrointestinal toxicity.…”

“…Quercetin (3,3'4',5, has been reported to show anti-inflammatory activity. However, its low oral bioavailability limits the application of quercetin in therapy.…”

A Review of Medicinal Uses and Pharmacological Activities of Tridax Procumbens (L.)

“…Luteolin seems to slow the migration and invasion of cancer cells , inhibits cell replication and DNA repair, which promote apoptosis (Yamashita and Kawanishi, 2000) and inhibits multidrug-resistant proteins (Rao et al, 2012) among other effects. Quercetin is an antioxidant, protecting against lipid peroxidation, with effective antiulcer activity against ethanol-induced ulcerogenesis (Coskun et al, 2004); it also increases the level of beta-carotene and decreases the level of retinol (Bando et al, 2010). All these properties indicate the potential applications of this remarkable plant.…”