The team investigated the effect of physiological concentrations of vitamin C on gastric cancer cells and Helicobacter pylori.
They reported their findings in the February issue of Gut.
Gastric juice vitamin C may be protective against gastric carcinogenesis but concentrations are significantly reduced by H. pylori infection.
Gastric cancer cell lines and various H. pylori strains were treated with L-ascorbic acid for up to 72 hours. The researchers determined cell viability, and protein and DNA synthesis.
| Vitamin C can alter H. pylori-induced cell cycle events.
Flow cytometry was used for assessment of H. pylori adherence, cell cycle distribution, and apoptosis.
H. pylori growth and its hemagglutination activity were determined using viability count and microtitration assay.
It was found that vitamin C induced a significant dose-dependent growth inhibition of gastric AGS and MKN45 cells. However, this effect was significantly reduced at levels similar to those in gastric juice of H. pylori infected patients (< 50 µM).
Vitamin C had no obvious effect on H. pylori growth, hemagglutination activity, or adherence ability to gastric AGS cells compared with untreated controls. However, it did significantly enhanced H. pylori-associated apoptosis and induced cell cycle arrest in these cells.
Dr Z. W. Zhang, of the Digestive Diseases Research Centre at St Bartholomew's and the Royal London School of Medicine, concluded on behalf of fellow authors, "Vitamin C may inhibit gastric cancer cell growth and alter H. pylori-induced cell cycle events, at concentrations comparable with those in gastric juice, but has no effect on H. pylori growth or pathogenicity.
"However, the inhibitory effect on gastric cancer cells was lost at vitamin C concentrations found in patients with H. pylori infection."