Bioaccessibility of bioactive compounds present in Persea americana Mill. seed ingredient during oral-gastric digestion with antibacterial capacity against Helicobacter pylori.

ETHNOPHARMACOLOGICAL RELEVANCE: In ancient Mexican cultures, the Persea americana Mill seed has been used against gastrointestinal diseases, due to high concentrations of bioactive compounds. According to Traditional Mexican Medicine, P. americana seed aqueous infusion is used against roundworms, intestinal worms, parasites, and gastrointestinal problems, in a dose taken over three or four days. In addition, Mexican Society of Natural History indicates the traditional use of P. americana seed powder as an antiparasitic, and antibacterial (MTM, 2009). On the other hand, Helicobacter pylori infection is a factor associated with the development of gastric disease, peptic ulcers as well as some types of gastric lymphomas and gastric cancer in humans; in this way is necessary scientific evidence about P. americana seed effect in gastrointestinal disease.

AIM OF THE STUDY: The work aimed to evaluate bioactive compounds bioaccessibility and antimicrobial potential against Helicobacter pylori during oral-gastric digestion in vitro of food ingredient from Persea americana Mill. seed and elucidate the possible action mechanism using in silico tools.

MATERIALS AND METHODS: Initially, P. americana seed oil and aqueous extract of P. americana seed were obtained using ultrasound and maceration respectively, and the food ingredient from P. americana seed was obtained. The samples underwent oral-gastric digestions by the INFOGEST method, to continue identifying and quantifying the bioactive compounds by HPLC-DAD and GC-MS. The anti-Helicobacter pylori activity determination were used fourteen Helicobacter pylori clinical strains and reference strains by Susceptibility testing by Minimal Inhibition Concentration, Kinetics of Growth Inhibition of H. pylori, Urease Inhibitory Kinetic. Finally, to elucidate a possible action mechanism used in silico tools (Software AutoDock 4.2.6 and BioVia Discovery v.19.1.0.1.18287).

RESULTS: The lipophilic fraction of P. americana seed detected oleic acid, linoleic acid, and avocadenofuran compounds, and the phenolic fraction showed the presence of catechin, rutin, ellagic, and chlorogenic acid, among others. Phenolic compounds conformational changes during oral-gastric digestion due to mechanical and acid hydrolysis, while lipophilic compounds showed a 20% increase in the gastric phase. Persea americana Mill. seed ingredient (3.08 μg/mL) showed total in vitro inhibition of clinical and reference strains of H. pylori, likewise, the lipophilic fraction had a lower inhibition concentration (2.59 μg/mL) regardless of the strains. Among the mechanisms found in silico, inhibition of target proteins such as CagA, BabA, and MUC5 were observed, as virulence factors involving adherence and bacterial pathogenicity.

CONCLUSIONS: This research provides evidence that food ingredient from P. americana seed has antimicrobial in vitro potential against H. pylori clinical strains, through phenolic and mainly lipophilic compounds, opening new scientific evidence that supports the P. americana seed's traditional use.