title: Antimicrobial and cytotoxic activity of red propolis: an alert for its safe use.
abstract: OBJECTIVE
  Red propolis is a resinous product popularly consumed in Brazil as it improves health, and it is considered a nutraceutical. The objective of this study was to test the antimicrobial activity of eight samples of red propolis from Brazil and Cuba to assess the possibility of application of this natural product as an antimicrobial agent, along with a study of its cytotoxic activity against non-tumor cell lines to evaluate at which concentrations it could be safely used.
  
  
  RESULTS
  The chemical profile of the samples was evaluated by UHPLC-MS. All the samples presented antimicrobial activity which was tested using agar diffusion and serial dilution methods; and these samples displayed a better activity against most Gram-negative bacteria with minimum inhibitory concentration (MIC) in the range between 6·25 μg ml(-1) and 500 μg ml(-1). However our studies also revealed an inherent cytotoxic effect against HaCaT human keratinocytes and BALBc 3T3.
  
  
  CONCLUSIONS
  To have a noncytotoxic and safe use of red propolis, it is necessary to use a concentration below the IC50 cytotoxic values.
  
  
  CONCLUSIONS
  The traditional use of propolis does not necessarily guarantee its safety. The evaluation of the safety of bioactive natural products should always be considered together with the evaluation of the activity.
authors.affiliation: Bioscience and Technology of Bioactive Products Postgraduate Program, Pharmacy Course, Department of Plant Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.
authors.forename: B G-C
authors.initials: BG
authors.lastname: Lopez
authors.affiliation: Plant Biology Postgraduate Program, Department of Plant Biology, Institute of Biology - State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.
authors.forename: C C
authors.initials: CC
authors.lastname: de Lourenço
authors.affiliation: Bioscience and Technology of Bioactive Products Postgraduate Program, Pharmacy Course, Department of Plant Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.|LABIOTEC - Biotechnology Laboratory, Department of Biochemistry, Institute of Biology, University of Campinas - UNICAMP, Campinas, São Paulo, Brazil.
authors.forename: D A
authors.initials: DA
authors.lastname: Alves
authors.affiliation: LABIOTEC - Biotechnology Laboratory, Department of Biochemistry, Institute of Biology, University of Campinas - UNICAMP, Campinas, São Paulo, Brazil.
authors.forename: D
authors.initials: D
authors.lastname: Machado
authors.affiliation: Bioscience and Technology of Bioactive Products Postgraduate Program, Pharmacy Course, Department of Plant Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.|LABIOTEC - Biotechnology Laboratory, Department of Biochemistry, Institute of Biology, University of Campinas - UNICAMP, Campinas, São Paulo, Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Lancellotti
authors.affiliation: Bioscience and Technology of Bioactive Products Postgraduate Program, Pharmacy Course, Department of Plant Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.
authors.forename: A C H F
authors.initials: AC
authors.lastname: Sawaya
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D041702:BALB 3T3 Cells; D001938:Brazil; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D003257:Consumer Product Safety; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000254:growth & development; D006801:Humans; D051379:Mice; D008826:Microbial Sensitivity Tests; D011429:Propolis / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity*
chemical_list: D000900:Anti-Bacterial Agents; D011429:Propolis
keywords: UHPLC-MS; antimicrobial activity; bioactive natural products; cytotoxicity; red propolis