Gastroprotection by dairy foods against stress-induced ulcerogenesis in rats

Development of the PC-NSAID technology: From contact angle to Vazalore®

We describe strategies in drug development to reduce the gastrointestinal (GI) toxicity of nonsteroidal anti-inflammatory drugs (NSAIDs). We then provide an overview of the experiments that led to the development of PC-NSAIDs, a novel family of NSAIDs associated with phosphatidylcholine (PC) that have reduced GI toxicity and full therapeutic activity. Furthermore, we describe the evidence showing: that the stomach possesses hydrophobic properties that are attributable to phospholipids lining the mucus gel layer; and that NSAIDs chemically associate with intrinsic PC, thereby attenuating the tissue's hydrophobic properties. Further, pre-associating NSAIDs with PC reduces the GI toxicity of these drugs, both in rodent ulcer models and in human subjects, without affecting the drugs' therapeutic activity. Finally, we discuss the commercialization and launch of Aspirin-PC, an over-the-counter (OTC) drug with the brand name Vazalore®.

Novel milk-based oral formulations: proof of concept

The aim of this study is to develop milk-based formulations for ionized and unionized lipophilic drugs. Solubility studies of the following non-steroidal anti-inflammatory drugs (NSAIDs): mefenamic acid, tolfenamic acid, ketoprofen, meloxicam, tenoxicam and nimesulide in phosphate- and glycine-NaOH buffers at nominal pH 8-12, were performed. The solubilities of cyclosporine and danazol in water-ethanol solutions were studied. NSAIDs-, cyclosporine-, danazol-, aspirin-milk oral liquid formulations were prepared by adding the appropriate volume of (i) NSAIDs-alkaline buffer solutions, (ii) water-ethanol solutions of cyclosporine and danazol and (iii) aspirin aqueous solution to 150-200ml of milk. All the non-steroidal anti-inflammatory drugs exhibited increased solubility in the alkaline buffers. The actual pH values (range 6.7-7.7) of the final NSAIDs-milk formulations were very close to milk pH. The higher ethanol content in ethanol-water mixtures increased the solubility of danazol and cyclosporine. A 15mg meloxicam-, a 100mg cyclosporine- and a 500mg aspirin-milk formulation was administered orally to healthy volunteers. All these formulations showed a satisfactory in vivo performance. The strong buffering capacity of milk that was observed and the high solubility of unionized drugs in ethanol allow the preparation of drug-milk formulations with enhanced pharmacokinetic properties.

Beneficial preventive effects of gastric mucosal lesion for soy-skim milk fermented by lactic acid bacteria

In this study, Lactobacillus paracasei subsp. paracasei NTU101 and Lactobacillus plantarum NTU 102 were used as starter to ferment soy-skim milk, and the optimal mixing ratio was evaluated. The influence of lactic acid bacteria (LAB)-fermented soy-skim milk on mucosal integrity in a gastric mucosal lesion rat model was also investigated. After 24 h, cell densities of L. paracasei subsp. paracasei NTU 101 and L. plantarum NTU 102 fermented in 75% soy milk and 25% milk (optimal condition) were 1.2 × 10(9) and 2.5 × 10(9) CFU/mL. After 180 days at 4 °C, the cell densities of the freeze-dried powders of the fermented soy-skim milks were 1 × 10(9) CFU/g; slight variations in pH and acidity were observed. Pylorus ligation with acidified ethanol treatment was used as the gastric lesion animal model. LAB-fermented soy-skim milk reduced the gastric lesion index and the lipid peroxides (LPO) of gastric mucosa and serum. Administration of the fermented soy-skim milk enhanced superoxide dismutase (SOD) activity and prostaglandin E(2) (PGE(2)) synthesis. Therefore, LAB-fermented soy-skim milk at 10(9) CFU/day protects against gastric injury.

Protective effect of polyunsaturated phosphatidylcholine pretreatment on stress ulcer formation in rats

PURPOSE

The aim of this study was to investigate whether polyunsaturated phosphatidylcholine. (PPC) pretreatment has any protective effect on gastric mucosal damage induced by cold-restraint stress (CRS) in rats.

METHODS

Forty swiss albino rats were divided into 3 groups. Group 1 (n = 10) was control, group 2 (n = 15) was stress ulcer, and group 3 (n = 15) was PPC-treated rats with stress ulcer. Stress ulcer was induced by the cold-restraint method for 4 hours at 4 degrees C after a starvation period of 72 hours. In the group 3 rats, PPC treatment was started 10 days before stress at a dose of 100 mg/d by oral route. Rats were terminated, stomachs were excised. Macroscopic ulcer index (UI), gastric tissue malondialdehyde (MDA) and superoxide dismutase (SOD) activities, plasma total nitrite, and erythrocyte catalase (CAT) concentrations were assayed.

RESULTS

Histopathologic examination showed a stress ulcer index of 0.12 +/- 0.19 mm in the treatment group and 23.6 +/- 8.97 mm in the stress ulcer group (P <.001). Tissue MDA and SOD concentrations were higher in the stress ulcer group than in the treatment group, the differences were statistically significant (P <.001). Plasma NO3-+ NO2- levels were higher (P<.005) and CAT levels were lower (P <.001) in the nontreatment group. There were no significant differences with respect to Ul, MDA, and SOD levels among the control and treatment groups (P >.05).

CONCLUSIONS

These results suggest that pretreating rats with PPC inhibits cold-restraint stress-induced gastric mucosal injury and might be useful in preventing stress-induced stomach ulcers.

The effects of food deprivation, nutritive and non-nutritive feeding and wheel running on gastric stress ulcers in rats

Feeding and housing conditions that induce gastric lesions were investigated. Rats were housed in activity wheels or in hanging cages and exposed to food deprivation, ad lib cellulose or 6 g of cellulose per day for 5 days. Food-deprived rats in both housing conditions had ulcers in the rumen but many rats also had mucosal ulcers. Cellulose prevented rumenal ulcers but produced a tendency toward more severe mucosal ulcers. Ulcers in wheel-housed rats were somewhat larger but the difference was not significant. In a second experiment, rats were fed 6 g/day laboratory chow or 6 g/day chow + ad lib cellulose until b.wt. reached a preset criterion. On the average, about 10 days on the feeding regimen were required to induce ulcers in these groups. None of the rats had rumenal ulcers. Mucosal ulcers were reliably larger in rats that received cellulose in addition to 6 g of chow. There was no difference in ulcer area between wheel-housed and cage-housed rats. The results indicate that solid bulk, regardless of its caloric value or amount, protects the nonglandular stomach whereas noncaloric bulk tends to aggravate ulcers in the glandular stomach. A small amount of chow delays the rate of b.wt. loss and consequently ulcer formation. Furthermore, wheel running is not necessary to produce mucosal ulcers when food intake is insufficient to maintain b.wt. and b.wt. at sacrifice seems to be a good predictor of ulcer formation.