title: The effects of Brazilian propolis on etiological agents of mastitis and the viability of bovine mammary gland explants.
abstract: The objective of this study was to evaluate in vitro the antimicrobial activity of Brazilian propolis from Urupema, São Joaquim, and Agua Doce (Santa Catarina State) and green propolis from Minas Gerais State, and the effects of propolis on bovine mammary gland explant viability. The propolis samples differed in flavonoid content and antioxidant activity. Green propolis showed the highest content of flavonoids, followed by the sample from São Joaquim. The propolis from Urupema showed the lowest flavonoid content along with the lowest antioxidant activity. The total phenolics were similar across all studied samples. Despite phytochemical differences, the propolis samples from Minas Gerais, São Joaquim, and Urupema presented the same level of antimicrobial activity against Staphylococcus aureus strains. The reduction in S. aureus growth was, on average, 1.5 and 4 log10 times at 200 and 500 μg/mL, respectively. At concentrations of 1,000 μg/mL, all propolis reduced bacterial growth to zero. On the other hand, when the propolis were tested against strains of Escherichia coli, the samples presented weak antimicrobial activity. Mammary explants were maintained in culture for 96h without a loss in viability, demonstrating the applicability of the model in evaluating the toxicity of propolis. The origin and chemical composition of the propolis had an effect on mammary explant viability. We encountered inhibitory concentrations of 272.4, 171.8, 63.85, and 13.26 μg/mL for the propolis from Água Doce, Urupema, São Joaquim, and Mina Gerais, respectively. A clear association between greater antimicrobial activity and toxicity for mammary explants was observed. Of all propolis tested, the Urupema sample was noteworthy, as it showed antimicrobial activity at less toxic concentrations than the other samples, reducing bacterial growth to an average of 9.3 × 10(2) cfu/mL after 6h of contact using 200 μg/mL of extract. The results demonstrate the potential for Brazilian propolis in the treatment of mastitis, although effectiveness is dependent on geographical origin and concentration. The results from the mammary gland explant assays are promising for the investigation of other natural products with antimicrobial and anti-inflammatory properties that can be used in the intramammary treatment of subclinical mastitis and during dry cow therapy.
authors.affiliation: Federal University of Santa Catarina, Florianópolis, Brazil, 88034-001.
authors.forename: Samira A L
authors.initials: SAL
authors.lastname: Fiordalisi
authors.affiliation: Desidério Finamor Veterinary Research Institute, Eldorado do Sul, Rio Grande do Sul, Brazil, 92990-000.
authors.forename: Luciana A
authors.initials: LA
authors.lastname: Honorato
authors.affiliation: Desidério Finamor Veterinary Research Institute, Eldorado do Sul, Rio Grande do Sul, Brazil, 92990-000.
authors.forename: Márcia R
authors.initials: MR
authors.lastname: Loiko
authors.affiliation: Federal University of Rio Grande do Sul, Porto Alegre, Brazil, 91540-000.
authors.forename: César A M
authors.initials: CAM
authors.lastname: Avancini
authors.affiliation: Biological Sciences Centre, Federal University of Santa Catarina, Florianópolis, Brazil, 88034-001.
authors.forename: Maria B R
authors.initials: MBR
authors.lastname: Veleirinho
authors.affiliation: Department of Animal Sciences, Agrarian Sciences Centre, Federal University of Santa Catarina, Florianópolis, Brazil, 88034-001.
authors.forename: Luiz C P Machado
authors.initials: LCPM
authors.lastname: Filho
authors.affiliation: Department of Animal Sciences, Agrarian Sciences Centre, Federal University of Santa Catarina, Florianópolis, Brazil, 88034-001. Electronic address: shirley.kuhnen@ufsc.br.
authors.forename: Shirley
authors.initials: S
authors.lastname: Kuhnen
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001938:Brazil; D002417:Cattle; D004926:Escherichia coli / Q000187:drug effects*; D005260:Female; D008321:Mammary Glands, Animal / Q000187:drug effects*; D011429:Propolis / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D011429:Propolis
keywords: antimicrobial activity; mammary gland explants; phytotherapy; toxicity