The effects of β-lapachone on gastric secretion were investigated. The pylorus of male Sprague-Dawley rats was ligated and intraduodenally injected with β-lapachone, and the volume, pH, free HCl, and total acidity of gastric fluid were measured 6 hours after the operation. Treatment with β-lapachone resulted in dose-dependent inhibition of gastric secretion Gastric fluid was reduced to 42.9% of control level by 100 mg/kg of β-lapachone, leading to an increase of pH to 6.70 from 1.85 in the control group. In parallel with the increase of pH, at this dosage, free HCl and total acidity decreased to 16.7% and 12.0%, respectively, of control levels. β-Lapachone exhibited ED50 values of 72, 46, and 47 mg/kg for inhibition of gastric volume, free HCl, and total acidity, respectively, implying a superior efficacy on gastric acid to volume. In comparison, pantoprazole (30 mg/kg) reduced the volume, free HCl and total acidity of gastric fluid to 53.0%, 26.0%, and 25.0%, respectively, of control levels, resulting in an increase in pH to 6.36. In the current study, it was confirmed that β-lapachone at an appropriate dose (100 mg/kg) exerted a higher inhibitory effect on gastric secretion than pantoprazole (30 mg/kg), a well-known proton-pump inhibitor. Therefore, it is suggested that β-lapachone could be a candidate compound for prevention or treatment of gastric ulcers induced by diverse psychological and physical stimuli.

Effects of carnitine on atherosclerosis and steatosis of hypercholesterolemic rabbits induced by a high-cholesterol diet (HCD) containing 0.5% cholesterol and 2.0% corn oil were investigated. Male New Zealand white rabbits with hypercholesterolemia (blood cholesterol 1,000-1,500 mg/dl) induced by two-week feeding a HCD, were fed a HCD containing 0.008 or 0.075% L-carnitine for an additional eight weeks. Feeding a HCD for 10 weeks resulted in severe atheromatous change, covering 55.7% of the aortic walls, in addition to profound hepatic steatosis. However, carnitine supplementation resulted in recovery of the increased low-density lipoproteins and triglycerides and a decrease in the levels of high-density lipoproteins following HCD feeding, although the increased cholesterol concentration was not potentially attenuated. Notably, carnitine induced a marked reduction of the atheroma area and hepatic lipid accumulation as well as lipid peroxidation. The results of this study indicated that carnitine exerted anti-atherosclerotic and fatty liver-preventing activities through blockade of lipid peroxidation and regulation of lipid metabolism.