Effects of <i>Apis mellifera</i> Propolis on the Activities of Streptococcal Glucosyltransferases in Solution and Adsorbed onto Saliva–Coated Hydroxyapatite

Abstract

Propolis, a resinous hive product collected by Apis mellifera bees, has been used for thousands of years in folk medicine. Ethanolic extracts of propolis (EEP) have been shown to inhibit the activity of a mixture of crude glucosyltransferase (Gtf) enzymes in solution. These enzymes synthesize glucans from sucrose, which are important for the formation of pathogenic dental plaque. In the present study, the effects of propolis from two different regions of Brazil on the activity of separate, purified Gtf enzymes in solution and on the surface of saliva–coated hydroxyapatite (sHA) beads were evaluated. The EEP from Minas Gerais (MG; Southeastern Brazil) and Rio Grande do Sul (RS; Southern Brazil) were tested for their ability to inhibit the enzymes GtfB (synthesis of insoluble glucan), GtfC (insoluble/soluble glucan) and GtfD (soluble glucan). The effects of propolis on Gtf from Streptococcus sanguis (soluble glucan synthesis) was also explored. The EEP from both regions effectively inhibited the activity of all Gtfs in solution (75–95%) and on the surface of sHA beads (45–95%) at concentrations between 0.75 and 3.0 mg of propolis/ml. However, the two samples of propolis showed different levels of inhibition on each of the enzymes tested. In general, EEP RS demonstrated a significantly higher inhibitory activity on GtfB and C activities (both solution and surface assays) than EEP MG at concentrations between 0.047 and 0.187 mg/ml (p<0.05). EEP MG, on the other hand, exhibited a greater inhibitory effect on the activities of surface GtfD (at 0.375, 0.75 and 1.5 mg/ml) and S. sanguis Gtf (at 1.5 and 3.0 mg/ml; p<0.05). These data indicate that EEP is a potent inhibitor of Gtf enzymes in solution and adsorbed on an experimental pellicle; however, its effect on Gtf activity is variable depending on the geographical origin of the propolis samples. There is a need to identify the active compounds of propolis.

Effects of Compounds Found in Propolis onStreptococcus mutansGrowth and on Glucosyltransferase Activity

“…The results obtained in the present study identified some of the compounds that may have been responsible for the previously reported effects of propolis on GTFs and bacterial growth (28,29,30,40). In general, flavonoids were the most active compounds, displaying distinct biological properties; flavones and flavonols were effective GTF inhibitors, whereas flavanones and the dihydroflavonol pinobanksin-3-acetate showed antibacterial activity.…”

“…For surface assays, the GTFs were adsorbed to hydroxyapatite beads coated with clarified whole saliva (free of GTF activity) as detailed elsewhere (30,43,51). The sHA beads were exposed to sufficient enzyme to saturate the surface as determined experimentally.…”

“…Propolis exhibits a wide range of biological activities, including antimicrobial, antiinflammatory, anesthetic, and cytostatic properties (8,17). Previously, we have demonstrated that two chemically distinct types of propolis from Brazil inhibited the activity of GTFs and the growth of S. mutans in vitro (28,29,30). Furthermore, topical application of propolis twice daily (27) or its inclusion in drinking water available ad libitum (25) reduced the incidence of dental caries in rats.…”

Estudo in vitro e ex vivo da ação de diferentes concentrações de extratos de própolis frente aos microrganismos presentes na saliva de humanos

“…Tal constatação confi rma que esse produto possui ação antimicrobiana contra os patógenos bucais (Ota & Valente, 1998;Pamplona, 1997 (Koo et al, 2000;Park et al1998;Ota & Valente, 1998).…”

Isolamento e identificação de compostos com atividade antibacteriana da própolis vermelha brasileira

“…Existem vários relatos atribuindo à própolis as mais variadas aplicações na medicina popular e, de fato, os estudos vêm corroborando que a própolis possui um grande potencial terapêutico, principalmente em relação às atividades antimicrobiana, antiinflamatória, cicatrizante, anestésica, antitripanossomal (GHISALBERTI, 1979;MAREKOV, 1989;KHAYYAL;ELGHAZALY;ELKHATIB, 1993;KUJUMGIEV et al, 1999;MARCUCCI et al, 2001;ALENCAR, 2002;MONTPIED et al, 2003, ALENCAR et al, 2007, anticariogênica (PARK et al 1998a;PARK et al, 1998b;KOO et al, 1999;KOO et al, 2000a;KOO et al, 2000b;ROSALEN et al, 2002;MURATA et al, 2003;DUARTE et al, 2003;HAYACIBARA et al, 2005;CASTRO et al, 2007), antiviral, anticarcinogênica, antioxidante (BURDOCK, 1998MARCUCCI, 1996;CHEN et al, 1996;BANKSOTA et al, 2000;ALENCAR, 2002;CHEN et al, 2003;NAGAI et al, 2003;ASO et al, 2004;ISHIKAWA et al, 2004;NAKAYAMA, 2004;OLDONI, 2007) e fitotóxica (GHISALBERTI, 1979;JOHNSON;EISCHEN;GIANASSI, 1994).…”