Impact of Long-Term Proton Pump Inhibitor Therapy on Gut Microbiota in F344 Rats: Pilot Study

BACKGROUND/AIMS: To evaluate changes in gut microbiota composition following long-term proton pump inhibitor (PPI) treatment. METHODS: Twenty-four-week-old F344 rats were fed diets with (n=6) or without (n=5) lansoprazole for 50 weeks. Profiles of luminal microbiota in the terminal ileum were then analyzed. Pyrosequencing of the 16S rRNA gene was performed using an FLX genome sequencer (454 Life Sciences/Roche). RESULTS: Rats treated with lansoprazole showed significantly reduced body weights compared to controls (lansoprazole-treated rats and controls, 322.3±15.3 g vs 403.2±5.2 g, respectively, p<0.001). However, stool frequencies and consistencies did not differ between the two groups. The composition of the gut microbiota in lansoprazole-treated rats was quite different from that of the controls. In the controls, the microbiota profiles obtained from the terminal ileum showed a predominance of Proteobacteria (93.9%) due to the abundance of Escherichia and Pasteurella genera. Conversely, lansoprazole-treated rats showed an elevated population of Firmicutes (66.9%), which was attributed to an increased ratio of Clostridium g4 to Lactobacillus genera. CONCLUSIONS: This preliminary study suggests that long-term administration of PPI may cause weight loss and changes to the microbiota in the terminal ileum.

Impact of Long-Term Proton Pump Inhibitor Therapy on Gut Microbiota in F344 Rats: Pilot Study

BACKGROUND/AIMS: To evaluate changes in gut microbiota composition following long-term proton pump inhibitor (PPI) treatment. METHODS: Twenty-four-week-old F344 rats were fed diets with (n=6) or without (n=5) lansoprazole for 50 weeks. Profiles of luminal microbiota in the terminal ileum were then analyzed. Pyrosequencing of the 16S rRNA gene was performed using an FLX genome sequencer (454 Life Sciences/Roche). RESULTS: Rats treated with lansoprazole showed significantly reduced body weights compared to controls (lansoprazole-treated rats and controls, 322.3±15.3 g vs 403.2±5.2 g, respectively, p<0.001). However, stool frequencies and consistencies did not differ between the two groups. The composition of the gut microbiota in lansoprazole-treated rats was quite different from that of the controls. In the controls, the microbiota profiles obtained from the terminal ileum showed a predominance of Proteobacteria (93.9%) due to the abundance of Escherichia and Pasteurella genera. Conversely, lansoprazole-treated rats showed an elevated population of Firmicutes (66.9%), which was attributed to an increased ratio of Clostridium g4 to Lactobacillus genera. CONCLUSIONS: This preliminary study suggests that long-term administration of PPI may cause weight loss and changes to the microbiota in the terminal ileum.

The Effect of Cochinchina momordica Seed Extract on Gastric Acid Secretion and Morphologic Change in Aged Rat Stomach

BACKGROUND/AIMS: Cochinchina momordica seed extract (SK-MS10) has a gastric protective effect. We aimed to assess the effect of SK-MS10 on gastric acid secretion with morphologic changes in the aged rat. METHODS: Acid secretions were evaluated in the male F344 rats of four different ages (6-, 31-, 74-week, and 2-year). The 31-week-old rats were divided to three groups and continuously administered chow containing vehicle, SK-MS10 and lansoprazole, respectively. At the age of 74 weeks and 2 years, basal and stimulated acid was measured and the expression of mRNA and protein of H(+)-K(+)-ATPase were determined. The area of connective tissue of lamina propria was measured. RESULTS: Basal and stimulated gastric acid significantly decreased and connective tissue of lamina propria increased with age. The expression of mRNA and protein of H(+)-K(+)-ATPase significantly decreased with age. However, 74-week-old rats in the SK-MS10 group had higher stimulated gastric acid secretion than those in the vehicle and lansoprazole groups. In 2-year-old rats of SK-MS10 group, there was no increase of connective tissue. CONCLUSIONS: As SK-MS10 kept the capacity of acid secretion as well as connective tissue area to comparable to young rats, it might valuable to perform further research regarding mechanism of SK-MS10 as an antiaging agent in the stomach.

Comparison of Indomethacin, Diclofenac and Aspirin-Induced Gastric Damage according to Age in Rats

BACKGROUND/AIMS: Aging gastric mucosa is known to have decreased mucosal defenses and increased susceptibility to injury by nonsteroidal anti-inflammatory drugs. Depending on the type of nonsteroidal anti-inflammatory drug (NSAID), the underlying mechanisms and the extent of damage to the stomach or intestine may differ. This study was performed to evaluate the acute gastric damage caused by different doses of indomethacin, diclofenac and aspirin in rats of various ages. METHODS: For the acute models, indomethacin (10, 20 or 40 mg/kg), diclofenac (40 or 80 mg/kg) or aspirin (100 mg/kg) was given to 7- and 25-week-old and 1-year-old Sprague-Dawley rats by intragastric gavage. The gross ulcer index, damage area as assessed by imaging, histological index, myeloperoxidase (MPO) activity, and cytosolic phospholipase A2 (cPLA2) levels were measured after 24 hours. RESULTS: The gross ulcer index and damage area increased with age in the presence of three NSAIDs (p<0.05). The increases in MPO levels induced by diclofenac and aspirin were significantly higher in 1-year-old than 7-week-old rats (p<0.05). cPLA2 expression induced by indomethacin (10 and 40 mg/kg) was greater in the 1-year-old rats, compared with 7-week-old rats (p<0.05). CONCLUSIONS: NSAID-induced acute gastric damage increased in a dose- and age-dependent manner.

Enhancement of Gastric Ulcer Healing and Angiogenesis by Cochinchina Momordica Seed Extract in Rats

Cochinchina momordica seed is the dried ripe seed of Momordica cochinchinensis, a perennial vine. The antiulcer effect of an extract from cochinchina momordica seeds (SK-MS10) was evaluated in a rat model of acetic acid-induced gastric ulcers. Gastric ulcers were produced by subserosal injection of acetic acid. SK-MS10 (200 mg/kg) or vehicle was administered orally once per day for 14 days after the acetic acid injection. The stomach was removed and the ulcer size measured at day 7 and 14 of the treatment. Expression of vascular endothelial growth factor (VEGF) was assessed by real-time RT-PCR and Western blot analysis. In addition, the microvasculature density (MVD) adjacent to the ulcer margin was examined by immunohistochemistry. The treatment with SK-MS10 for 7 and 14 days significantly accelerated ulcer healing and increased the expression of mRNA (at day 7) as well as VEGF protein (at day 14) compared to the vehicle-treated rats. The MVD for factor VIII was also higher in the SK-MS10 treatment group compared to the vehicle-treated rats; however, these differences were not statistically significant. These results suggest that SK-MS10 treatment accelerates the healing of gastric ulcers via upregulation of VEGF and angiogenesis in an acetic acid rat model.

The Neuroprotective Effect of Ginexin on Rat Retinal Ganglion Cell in Optic Nerve Crush Injury Model

PURPOSE: To investigate the neuroprotective effect of Ginexin (Ginkgo biloba extract) on rat retinal ganglion cell in the optic nerve crush injury model. METHODS: From 1 week before the optic nerve injury, Ginexin 100 mg/kg/day (100 mg group), 200 mg/kg/day (200 mg group) or carboxymethylcellulose as a control group (CMC group) was administrated orally 4 weeks in Spraque-Dawley rats. At 3 weeks after the optic nerve injury, the RGCs were counted and the concentration of intravitreal glutamate was measured. RESULTS: The RGC density of CMC group (103+/-22 cells/mm2) was significantly lower than that of 100 mg group (182+/-39 cells/mm2) and 200 mg group (201+/-63 cells/mm2). There was no difference between the 100 mg group and 200 mg group. The concentration of invtravitreal glutamate did not significantly differ among normal, CMC group, 100 mg group and 200 mg group. CONCLUSIONS: Ginexin increased the survival of the retinal ganglion cell in rat optic nerve crush injury model, but, did not influence on the concentration of intravitreal glutamate.