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

Abstract

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.

Keywords: Aging; Cochinchina momordica seed; Connective tissue; Gastric acid; Hydrogen-potassium-activated ATPase.

Fig. 1

Gastric acid secretion and expression of H⁺-K⁺-ATPase with age. (A) Basal and stimulated acid concentration. (B) Basal and stimulated acid concentration corrected by body weight. (C) The volume of gastric acid secretion. The volume of basal gastric secretion was not different among each age group. The volume of stimulated gastric secretion peaked in the 31-week-old rat group and decreased with age. (D) pH of gastric acid. pH of stimulated gastric acid of 74-week- and 2-year-old rats was significantly higher than that of young age groups. (E) Expression of ATP4A mRNA. (F) Expression of H⁺-K⁺-ATPase protein. For the measurement of basal or stimulated acid secretion, either phosphate-buffered solution or histamine (40 mg/kg) and carbachol (10 µg/kg) was injected (s.c.), respectively. Results are expressed as mean±SEM. b.wt., body weight; OD, optical density. ^*p<0.05 compared with 6-week of age; ^†p<0.05 compared with 31-week of age; ^‡p<0.05 compared with 2-year-aged F344 rats.

Fig. 2

Gastric acid secretion and expression of H⁺-K⁺-ATPase according to drug. (A) Basal and stimulated acid concentration. (B) The volume of gastric acid secretion. The volume of basal gastric secretion of 74-week group was not different among each treatment group. The volume of stimulated gastric secretion of 74-week SK-MS10 was higher compared to other treatment groups with statistical significance. (C) pH of gastric acid. The basal pH of gastric acid of 74-week SK-MS10 group was lower than that of other two groups (p=0.027 compared to vehicle, p=0.016 compared to lansoprazole). In the 2-year-old rat groups, the basal pH of gastric acid did not show statistical significant difference among each treatment groups. pH of stimulated gastric acid show the lowest level in 74-week- and 2-year-old SK-MS10 groups. (D) Expression of ATP4A mRNA. (E) Expression of H⁺-K⁺-ATPase protein. The feeding period of SK-MS10 or lansoprazole was 43 weeks in the 74-week-old rats and 73 weeks in the 2-year-old (104-week-old) rats because the feeding was started at the age of 31 weeks. Results are expressed as mean±SEM. OD, optical density. ^*p<0.05 compared with vehicle; ^†p<0.05 compared with lansoprazole.

Fig. 3

Photomicrographs of gastric mucosa (H&E stain, ×400). (A) Vehicle of 74-week. (B) Vehicle of 2-year. (C) SK-MS10 of 74-week. (D) SK-MS10 of 2-year. (E) Lansoprazole of 74-week. (F) Lansoprazole of 2-year. Arrows indicate the layer of lamina propria.

Fig. 4

(A)Comparison of connective tissue area in the laminar propria. The proportion of connective tissue area of the 2-year-old F344 rats was significantly lower in the SK-MS10 group compared to vehicle or lansopraozole group. (B) Salt soluble collagen. (C) Sulfated GAG (sGAG). (D) Lipid hydroperoxide (LPO) according to continuous administration of SK-MS10 (100 mg/kg/day) from 31-week-old up to 74-week- or 2-year-old. ^*p<0.05 compared with vehicle; ^†p<0.05 compared with lansoprazole.