ABSTRACT
Brazilian green and red propolis stand out as commercial products for different medical applications. In this article, we report the antimicrobial activities of the hydroalcoholic extracts of green (EGP) and red (ERP) propolis, as well as guttiferone E plus xanthochymol (8) and oblongifolinâ B (9) from red propolis, against multidrug-resistant bacteria (MDRB). We undertook the minimal inhibitory (MIC) and bactericidal (MBC) concentrations, inhibition of biofilm formation (MICB50 ), catalase, coagulase, DNase, lipase, and hemolysin assays, along with molecular docking simulations. ERP was more effective by displaying MIC and MBC values <100â µg mL-1 . Compoundsâ 8 andâ 9 displayed the lowest MIC values (0.98 to 31.25â µg mL-1 ) against all tested Gram-positive MDRB. They also inhibited the biofilm formation of S. aureus (ATCC 43300 and clinical isolate) and S. epidermidis (ATCC 14990 and clinical isolate), with MICB50 values between 1.56 and 6.25â µg mL-1 . The molecular docking results indicated thatâ 8 andâ 9 might interact with the catalase's amino acids. Compounds 8 and 9 have great antimicrobial potential.
Subject(s)
Anti-Infective Agents/pharmacology , Drug Resistance, Multiple, Bacterial/drug effects , Propolis/chemistry , Anti-Infective Agents/chemistry , Anti-Infective Agents/metabolism , Bacterial Proteins/chemistry , Bacterial Proteins/metabolism , Benzophenones/chemistry , Benzophenones/isolation & purification , Benzophenones/metabolism , Benzophenones/pharmacology , Binding Sites , Biofilms/drug effects , Brazil , Catalase/chemistry , Catalase/metabolism , Catalytic Domain , Microbial Sensitivity Tests , Molecular Docking Simulation , Propolis/metabolism , Propolis/pharmacology , Staphylococcus aureus/drug effects , Staphylococcus aureus/physiologyABSTRACT
Propolis is one of the most widely used products in traditional medicine. One of the most prominent types of Brazilian propolis is the red one, whose primary botanical source is Dalbergia ecastaphyllum (L.) Taub. Despite the potential of Brazilian red propolis for developing new products with pharmacological activity, few studies guarantee safety in its use. The objective of this study was the evaluation of the possible toxic effects of Brazilian red propolis and D. ecastaphyllum, as well as the cytotoxicity assessment of the main compounds of red propolis on tumoral cell lines. Hydroalcoholic extracts of the Brazilian red propolis (BRPE) and D. ecastaphyllum stems (DSE) and leaves (DLE) were prepared and chromatographed for isolation of the major compounds. RP-HPLC-DAD was used to quantify the major compounds in the obtained extracts. The XTT assay was used to evaluate the cytotoxic activity of the extracts in the human fibroblast cell line (GM07492A). The results revealed IC50 values of 102.7, 143.4, and 253.1 µg/mL for BRPE, DSE, and DLE, respectively. The extracts were also evaluated for their genotoxic potential in the micronucleus assay in Chinese hamster lung fibroblasts cells (V79), showing the absence of genotoxicity. The BRPE was investigated for its potential in vivo toxicity in the zebrafish model. Concentrations of 0.8-6.3 mg/L were safe for the animals, with a LC50 of 9.37 mg/L. Of the 11 compounds isolated from BRPE, medicarpin showed a selective cytotoxic effect against the HeLa cell line. These are the initial steps to determine the toxicological potential of Brazilian red propolis.
