Gastroprotective effects of Caragana ambigua stocks on ethanol-induced gastric ulcer in rats supported by LC-MS/MS characterization of formononetin and biochanin A.

BACKGROUND: Caragana ambigua has been the part of the dietary routines of the regional people in south-west Pakistan and has traditionally been used for the treatment of diabetes there. There is an increased production of reactive oxygen species in diabetics, leading to gastrointestinal disorders. Natural antioxidants exhibit gastroprotective effects owing to their free-radical scavenging action. C. ambigua possesses appreciable phenolic and flavonoid content; thus, it has the potential to protect against gastrointestinal disorders (e.g. gastric ulcer). RESULTS: This study reports the anti-ulcer potential of C. ambigua. Four different fractions (chloroform, ethyl acetate, butanol, and aqueous) of plant were compared against omeprazole. Ulcer index, ulcer inhibition percentage, gastric pH and volume, total acidity, gastric protein, gastric wall mucus, and histopathology of gastric walls of rats were assessed. All fractions exhibited a reduction in ulcer index and promotion of percentage of ulcer inhibition compared with the ulcer control group. Furthermore, the fractions revealed a significant (P < 0.001) diminution in gastric volume and total acidity with an increase in pH. Among the fractions investigated, the chloroform fraction unveiled the most promising anti-ulcer activity, which is comparable to omeprazole. Liquid chromatography-tandem mass spectrometry screening of fractions revealed the presence of formononetin and biochanin A (isoflavones reported to have anti-ulcer properties) in the chloroform fraction. CONCLUSION: This study establishes that C. ambigua possesses significant potential in reducing gastric ulcer progression. Formononetin and biochanin A are chiefly responsible for the stated bioactivity due to the fact that these compounds were solely present in the chloroform fraction. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Isolation of antioxidative peptide from the protein hydrolysate of Caragana ambigua seeds and its mechanism for retarding lipid auto-oxidation.

BACKGROUND: Peptides can act as antioxidants in emulsion, although the mechanism involved is poorly understood. Caragana ambigua seed is a potential protein source for which the commercial applications have not been explored yet. In the present study, we aimed to evaluate the bio-economic potential of C. ambigua by isolating and characterizing antioxidative peptides from the protein hydrolysate of its seeds for the purpose of protecting lipids from oxidation. RESULTS: A novel decapeptide, identified as QITEGEDGGG, was purified by high-protein liquid chromotography based on the enrichment of antioxidant fractions, and its antioxidative activity for walnut oil was evaluated in terms of its effect on oil quality, primary and secondary peroxide formation, oxidation kinetics, and structure of oil droplets. A molecular simulation involving the peptide and fatty acid was carried out aiming to understand the mechanism underlying the prevention of lipid oxidation by the peptide. The peptide effectively scavenged superoxide anions (86.46%), inhibited the rate of linoleic acid oxidation (60.37%) and delayed auto-oxidation of walnut oil. Its inhibition of lipid oxidation was attributed to the protection of phenolic compounds and polyunsaturated fatty acids of walnut oil. CONCLUSION: The findings of the present study will help in the exploitation of novel antioxidant peptides of lipids from woody seed-based protein sources such the seeds of C. ambigua trees. © 2018 Society of Chemical Industry.