Protective effects of acetaminophen on ibuprofen-induced gastric mucosal damage in rats with associated suppression of matrix metalloproteinase.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are known to cause gastric mucosal damage as a side effect. Acetaminophen, widely used as an analgesic and antipyretic drug, has gastroprotective effects against gastric lesions induced by absolute ethanol and certain NSAIDs. However, the mechanisms that underlie the gastroprotective effects of acetaminophen have not yet been clarified. In the present study, we examined the role and protective mechanism of acetaminophen on ibuprofen-induced gastric damage in rats. Ibuprofen and acetaminophen were administered orally, and the gastric mucosa was macroscopically examined 4 hours later. Acetaminophen decreased ibuprofen-induced gastric damage in a dose-dependent manner. To investigate the mechanisms involved, transcriptome analyses of the ibuprofen-damaged gastric mucosa were performed in the presence and absence of acetaminophen. Ingenuity pathway analysis (IPA) software revealed that acetaminophen suppressed the pathways related to cellular assembly and inflammation, whereas they were highly activated by ibuprofen. On the basis of gene classifications from the IPA Knowledge Base, we identified the following five genes that were related to gastric damage and showed significant changes in gene expression: interleukin-1ß (IL-1ß), chemokine (C-C motif) ligand 2 (CCL2), matrix metalloproteinase-10 (MMP-10), MMP-13, and FBJ osteosarcoma oncogene (FOS). Expression of these salient genes was confirmed using real-time polymerase chain reaction. The expression of MMP-13 was the most reactive to the treatments, showing strong induction by ibuprofen and suppression by acetaminophen. Moreover, MMP-13 inhibitors decreased ibuprofen-induced gastric damage. In conclusion, these results suggest that acetaminophen decreases ibuprofen-induced gastric mucosal damage and that the suppression of MMP-13 may play an important role in the gastroprotective effects of acetaminophen.

Effects of Enteric-coated Lactoferrin Tablets Containing Lactobacillus brevis subsp. coagulans on Fecal Properties, Defecation Frequency and Intestinal Microbiota of Japanese Women with a Tendency for Constipation: a Randomized Placebo-controlled Crossover Study.

The effects of oral administration of enteric-coated tablets containing lactoferrin (LF; 100 mg/tablet) and heat-killed Lactobacillus brevis subsp. coagulans FREM BP-4693 (LB; 6×10(9) bacteria/tablet) on fecal properties were examined in 32 Japanese women (20-60 years of age) with a tendency for constipation (defecation frequency at equal to or less than 10 times/2 weeks) by a double-blind placebo-controlled crossover design. A significant increase in defecation days per week was obserbed in the subjects who ingested the tablets containing LF and LB compared with the placebo group. The number of bifidobacteria in feces also significantly increased compared with the placebo group. In an in vitro study, LF and tryptic hydrolysate of LF, but not peptic hydrolysate of LF, upregulated the growth of Bifidobacterium longum ATCC15707 when added to the culture. These results demonstrate the capability of the enteric-coated tablets containing LF and LB in improving intestinal function and suggest that they have a growth promoting function for bifidobacteria.

The effects of vitamin A compounds on hyaluronic acid released from cultured rabbit corneal epithelial cells and keratocytes.

A role of vitamin A in the synthesis of hyaluronic acid by skin cells is well known. Hyaluronic acid is produced by corneal epithelial cells and keratocytes in the eye. We investigated whether rabbit corneal epithelial cells and keratocytes release hyaluronic acid after exposure to vitamin A compounds. Rabbit corneal epithelial cells and keratocytes were inoculated with RCGM2 medium and incubated at 37ºC under 5% CO(2) in air for 24 h. The medium was then replaced with medium containing 0.1, 1, 10, or 100 µM retinoic acid or retinol palmitate (VApal) and incubated for another 48 h. Hyaluronic acid release from both corneal epithelial cells and keratocytes during culture was increased by retinoic acid at the lower concentration of 0.1 µM and 1 µM determined with a sandwich binding protein assay kit. However, it was significantly decreased at the higher concentrations of 10 µM and 100 µM, and the cell count determined with a Neutral Red assay kit was also decreased at these concentrations. On the other hand, hyaluronic acid release from corneal epithelial cells during culture was increased by VApal at the lower concentration of 0.1 µM and 1 µM, but there was no significant difference in the cell count for either corneal epithelial cells or keratocytes in the presence of VApal at any concentration. In conclusion, it is suggested that vitamin A stimulates the release of hyaluronic acid from cultured rabbit corneal epithelial cells and keratocytes.