Antimicrobial and Antidiarrheal Activities of Methanolic Fruit Peel Extract of Pouteria caimito

Introduction: Pouteria caimito is a native Amazonian fruit specie, popularly known as "abiu", that belongs to the Sapotaceae family. It has a wide popular use to relieve diarrhea, cough, fever and inflammation, among other purposes. However, few reports in the scientific literature deal with its phytochemical composition and biological activity. This study aimed to evaluate the antidiarrheal and antimicrobial activity of Pouteria caimito fruit peel extract. Methods: The antidiarrheal activity was evaluated in mice, using modulation models of normal defecation, cathartic agent-induced diarrhea and stimulated intestinal transit. Antimicrobial activity was, in turn, analyzed against strains of gram-positive and gram-negative bacteria (E. coli, S. epidermidis, S. aureus, Klebsiella pneumonie, E. faecalis and Salmonella tiphy) through the determination of the minimum inhibitory concentration (MIC) by the microdilution in broth method. Results: This study showed that there was no antidiarrheal activity in the experimental models analyzed and that the methanolic extract of P. caimito (MEPC) can positively modulate normal defecation. Regarding the antimicrobial activity, the crude extract and the ethyl acetate fraction presented a satisfactory action against most of the strains evaluated except for Enterococcus faecalis and Salmonella tiphy. Conclusions: The MEPC did not present any measurable antidiarrheal activity, but more possibly a laxative effect. The extract and acetate fraction showed antimicrobial activity against strains of gram-positive and gram-negative bacteria. The activity of the crude extract was more potent than the results obtained by the use of acetate fractions; the fractions with lower polarity did not present any relevant antimicrobial activity.