Gastric Acid-reducing Effect and Bioactive Compound Content of Leaves of Capparis sepiaria L. and Maerua angolensis DC (Capparidaceae)

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Résumé

In traditional medicine, the leaves of Capparis sepiaria and Maerua angolensis, known as kal-yanga and Zilogo respectively in the local Moore language, are used to treat gastric and duodenal ulcers and other gastrointestinal disorders. This study aimed firstly to evaluate in vivo the ability of the extracts to reduce gastric acidity and secondly to determine the contents of bioactive compounds potentially responsible for this effect. The pylorus ligation model in rats was used to assess the plant extracts effect on gastric acidity. Total phenolics were determined using the Folin–Ciocalteu reagent, while the flavonoid, condensed tannin, and hydrolysable tannin contents were determined by the aluminum trichloride, vanillin and sodium iodate method respectively. The best gastric acid-reducing activity equal to 32.88 milliequivalent of hydrogen ions per liter (mEq H+/L) was obtained with the Maerua angolensis leaves extract at a dose of 500 mg/kg.w.c., compared to the effect of the reference substance, omeprazole (24.88 mEq H+/L) used at 150 mg/kg.w.c. Quantification of the compounds potentially responsible for this activity showed high levels of total phenolic (637.80 mg GAE/g) and tannins (209.27 ± 45.94 mg CE/g; 175.08 ± 11.42 mg TAE/g) condensed and hydrolysable respectively for Capparis sepiaria, and a high level of total flavonoids (53.35 ± 3.10 mg QE/g) for Maerua angolensis. These two plants represent important sources for the development of new improved traditional medicines or nutraceuticals for the management of gastroduodenal ulcers.

Mots-clés

Maerua angolensis, Capparis sepiaria, Ulcer, Acidity, Flavonoids