Fresh fruit and vegetables exert multiple biological effects on the gastrointestinal mucosa.
With the aim to assess whether apple extracts counteract oxidative or indomethacin induced damage to gastric epithelial cells in vitro and to rat gastric mucosa in vivo.
Apple extracts were obtained from freeze dried apple flesh of the "Annurca" variety.
Cell damage was induced by incubating MKN 28 cells with xanthine-xanthine oxidase or indomethacin and quantitated by MTT.
In vivo gastric damage was induced by indomethacin 35 mg/kg.
Intracellular antioxidant activity was determined using the (2,2'-azinobis (3-ethylbenzothiazolin-6-sulfonate) method.
Malondialdehyde intracellular concentration, an index of lipid peroxidation, was determined by high pressure liquid chromatography with fluorometric detection.
The results of the study showed that apple extracts:
- decreased xanthine-xanthine oxidase or indomethacin induced injury to gastric epithelial cells by 50%;
- caused a fourfold increase in intracellular antioxidant activity;
- prevented its decrease induced by xanthine-xanthine oxidase;
- counteracted xanthine-xanthine oxidase induced lipid peroxidation;
- decreased indomethacin injury to the rat gastric mucosa by 40%.
Also the results showed that catechin or chlorogenic acid (the main phenolic components of apple extracts) were equally effective as apple extracts in preventing oxidative injury to gastric cells;
Apple extracts prevent exogenous damage to human gastric epithelial cells in vitro and to the rat gastric mucosa in vivo.
This effect seems to be associated with the antioxidant activity of apple phenolic compounds.
A diet rich in apple antioxidants might exert a beneficial effect in the prevention of gastric diseases related to generation of reactive oxygen species.
In this regard, consumption of diets rich in antioxidants and anti-inflammatory polyphenolics, such as those found in fruits and vegetables, may lower the risk of developing age-related neurodegenerative diseases.
Research suggests that the polyphenolic compounds found in apples, berry fruits, such as blueberries and strawberries, may exert their beneficial effects either through their ability to lower oxidative stress and inflammation or directly by altering the signaling involved in neuronal communication, calcium buffering ability, neuroprotective stress shock proteins, plasticity, and stress signaling pathways.