Use of natural substances for boar semen decontamination

Abstract

ABSTRACT:The aim of this study was to investigate the antibacterial activity and toxicity for sperm cells of the natural substances gallic acid, methyl gallate, ethyl gallate, propyl gallate, octyl gallate, thymol, carvacrol and eugenol. The antibacterial activity of these natural substances and selected combinations of them against bacterial strains isolated from boar ejaculates was determined using the microdilution and macrodilution method in Mueller-Hinton broth. The most effective natural substances against Gram-negative and Gram-positive bacteria included in our study were thymol and carvacrol with minimum inhibitory concentration (MIC) values in the range of 300-600 µg/ml. Gallic acid exhibited the best antibacterial activity against Pseudomonas aeruginosa strains (MIC values of 300-2400 µg/ml), whereas the ranges of MIC values against Escherichia coli, Enterococcus faecalis and Staphylococcus sp. strains were higher. Octyl gallate exhibited stronger antibacterial activity against staphylococci and enterococci (MIC values of 18.8-75 µg/ml) than against Escherichia coli and Pseudomonas aeruginosa strains with MIC values in the ranges of 300-600 µg/ml and 1200-2400 µg/ml, respectively. Thymol combined with carvacrol was the most effective combination against enterococci (MIC values of 75-300 : 150 thymol : carvacrol) and Pseudomonas aeruginosa (MIC values of 75-300 : 300 thymol : carvacrol), bacteria which are known to be frequently resistant to antimicrobials. Similar results were determined for the combination of carvacrol and eugenol against staphylococci and enterococci. The results of the combinations revealed more of an additive rather than a synergistic effect. Thymol and carvacrol were the most effective natural substances against the bacteria included in this study, with a low toxicity for sperm cells compared to other substances, suggesting their possible use for boar semen decontamination.

Contaminantes bacterianos y perfil de susceptibilidad del semen porcino en centros de recogida em Brasil

“…These authors also observed that agents related to this family contaminated 40.68% of semen samples assessed, and these are related to reduced motility and increased sperm pathologies. Moreover, these microorganisms might be involved in inflammatory processes of the endometrium of inseminated sows (5,24). While sperm motility, sperm morphology, and concentration of the SD produced are the parameters commonly used to assess semen quality, the microbiological evaluation is not a routine practice in boar semen evaluation, and may indicate other potential indicators of poor semen quality.…”

“…Estos autores también observaron que los agentes relacionados con esta familia contaminaron el 40,68% de las muestras de semen evaluadas, y éstos están relacionados con la reducción de la motilidad y el aumento de las patologías espermáticas. Además, estos microorganismos pueden estar implicados en procesos inflamatorios del endometrio de las cerdas inseminadas (5,24). Aunque la motilidad de los espermatozoides, su morfología y la concentración de la DS producida son los parámetros comúnmente utilizados para evaluar la calidad del semen, la evaluación microbiológica no es una práctica rutinaria en la evaluación del semen porcino, y puede indicar otros posibles indicadores de mala calidad.…”

Synergistic Antibacterial Effects of Chitosan-Caffeic Acid Conjugate against Antibiotic-Resistant Acne-Related Bacteria

“…In this study, chitosan-phytochemical conjugates were synthesized by conjugating HAs with chitosan following the previous method [17,24]. It was then assessed for the antibacterial activity of chitosan-phytochemical conjugates against acne-related bacteria.…”

“…Hydroxycinnamic acids (HAs) (having sinapic acid, caffeic acid, and ferulic acid) are naturally occurring phytochemicals from plants and have been used in pharmaceuticals, cosmetics, and the food industry [ 21 , 22 , 23 ]. In this study, chitosan-phytochemical conjugates were synthesized by conjugating HAs with chitosan following the previous method [ 17 , 24 ]. It was then assessed for the antibacterial activity of chitosan-phytochemical conjugates against acne-related bacteria.…”

Synergistic Antibacterial Effects of Chitosan-Caffeic Acid Conjugate against Antibiotic Resistant Acne-Related Bacteria

“…CFA and CSA showed the MIC values of 16 μg/mL to 256 μg/mL against acne-related bacteria. Interestingly, chitosan, and the chitosan-phytochemical conjugates showed very strong antibacterial activity against P. aeruginosa in the MICs range of 16 to 32 μg/mL, while Mazurova et al [21] reported that MICs of natural substances (gallic acid, methyl gallate, ethyl gallate, propyl gallate, octyl gallate, carvacrol, thymol, and eugenol) have range of 300 to 2,400 μg/mL. Generally, P. aeruginosa has high-level resistance to antibiotics and substances derived from natural materials due to the low permeability and the action of multidrug efflux pumps [5,22].…”