Isolation and identification of bioactive compounds from geopropolis (Melipona scutellaris) bioguided by antimicrobial activity in dental biofilms

Abstract

Considering the immense variety of plant species worldwide, natural products have been proposed as a promising source to the discovery of new bioactive compounds. Among those, propolis collected by Apis mellifera bees has relevant biological activities described in literature as anticaries, antibacterial, antioxidant, antiinflammatory, anticancer, among others. As regards anticaries property, propolis and its chemical isolates were shown to present strong correlation with anti-oral biofilm activity, acting on viability and virulence of mutans Streptococci. Howsoever, most studies on propolis refer to A. mellifera bees and few is known about others such as geopropolis, which is produced by stingless bees (Melipona scutellaris). Recent studies have pointed out a strong and promising antimicrobial and anti-inflammatory activity of geopropolis. Nevertheless, it has not been evidenced yet which substance is responsible for such biological properties, especially upon cariogenic oral biofilm. Thus, this investigation aims at continuing a previous study on geopropolis, supported by FAPESP, focusing on isolation and identification of active compound(s) from M. scutellaris geopropolis which may present activity against S. mutans biofilm formation. In this perspective, the following methodological actions will be employed: 1- Obtaining M. scutellaris geopropolis, producing its ethanolic extract (EEGP) and fractioning it as hexane (active fraction, identified in the previously mentioned study). 2- Chemical and antimicrobial monitoring of EEGP and hexane fraction aiming to confirm previous findings; 3- Subfractioning the hexane fraction in dry column and Sephadex LH-20 bioguided by chemical and biological monitoring to locate the subfraction showing the best activity upon S. mutans; 4- Chemical isolation of components will be performed from the active subfraction; 5- The bioactive isolated compound will be assessed by means of tests of microbial and biochemical viability of the S. mutans biofilm matrix. It will be considered as bioactive the compound which presents the best antimicrobial activity; and 6- After selecting the bioactive isolate, it will be chemically identified (molecularly and structurally) by high complexity analytic techniques (RMN and Q-TOF). Thus, it is expected to generate new knowledge based on the previous researches, in view of isolating and identifying chemically the geopropolis bioactive compound against S. mutans biofilm and that such substance (new or not) may be promising in the development of a drug to be used in the medical and dental field in a not too distant future. (AU)