Maytenus salicifolia Reissek (Celastraceae): evaluation of the activity of extracts and constituents against Helicobacter pylori and oral pathogenic microorganisms

Abstract

Maytenus salicifolia Reissek is known as "cafezinho" in Minas Gerais State, Brazil. Its leaves have been used in folk medicine to treat stomach ulcers. The present study reports the isolation of 4´-O-methylepigallocatechin (1) and proanthocyanidin A (2) of root (1; 4.36%; 2, 2.17%) and branch (1, 4.16%; 2, 0.26%) polar extracts from M. salicifolia. These compounds were found in the roots of this species for the first time. These constituents were found in large amounts and it makes M. salicifolia a suitable source of these compounds. Moreover, the antimicrobial activity of polar (ethanolic from roots, ethanolic and ethylacetate from branches) and non-polar (hexanic from roots) extracts from this plant was evaluated in vitro against oral pathogens such as Candida albicans, Streptococcus mutans, Streptococcus sanguinis and Staphylococcus aureus. All extracts showed antimicrobial activity and C. albicans was the most sensitive microorganism. The triterpenes nepeticin, rigidenol, glochidone, 11- hydroxyglochidone and 16--hydroxypristimerin, which were previously isolated from this species, were also assayed against Helicobacter pylori. Rigidenol and 16--hydroxypristimerin exhibited activity against this bacterium. These results contribute to confirm the traditional use of M. salicifolia to treat ulcer and other gastrointestinal problems. They also indicated that the extracts from this plant have the potential to be used in the treatment of infectious diseases of the oral cavity.