Essential Oils Extracted from Organic Propolis Residues: An Exploratory Analysis of Their Antibacterial and Antioxidant Properties and Volatile Profile

Abstract

The industrial processing of crude propolis generates residues. Essential oils (EOs) from propolis residues could be a potential source of natural bioactive compounds to replace antibiotics and synthetic antioxidants in pig production. In this study, we determined the antibacterial/antioxidant activity of EOs from crude organic propolis (EOP) and from propolis residues, moist residue (EOMR), and dried residue (EODR), and further elucidated their chemical composition. The EOs were extracted by hydrodistillation, and their volatile profile was tentatively identified by GC-MS. All EOs had an antibacterial effect on Escherichia coli and Lactobacillus plantarum as they caused disturbances on the growth kinetics of both bacteria. However, EODR had more selective antibacterial activity, as it caused a higher reduction in the maximal culture density (D) of E. coli (86.7%) than L. plantarum (46.9%). EODR exhibited mild antioxidant activity, whereas EOMR showed the highest antioxidant activity (ABTS = 0.90 μmol TE/mg, FRAP = 463.97 μmol Fe2+/mg) and phenolic content (58.41 mg GAE/g). Each EO had a different chemical composition, but α-pinene and β-pinene were the major compounds detected in the samples. Interestingly, specific minor compounds were detected in a higher relative amount in EOMR and EODR as compared to EOP. Therefore, these minor compounds are most likely responsible for the biological properties of EODR and EOMR. Collectively, our findings suggest that the EOs from propolis residues could be resourcefully used as natural antibacterial/antioxidant additives in pig production.

Antifungal Properties of Chemically Defined Propolis from Various Geographical Regions

“…Antifungal activities of various extracts of propolis have been examined against several yeasts, such as Candida albicans, C. dubliniensis, C. glabrata, C. krusei, C. parapsisolis, C. tropicalis, Saccharomyces cerevisiae [13,[16][17][18]21,50,[54][55][56][57][60][61][62][63][64], as well as against molds, such as Alternaria solani, Alternaria alternata, Aspergillus niger, Aspergillus ochraceus, Botrytis cinerea, Cladosporium spp., Fusarium solani, Fusarium oxysporum, Mucor mucedo, Penicillium digitatum, Penicillium expansum, Penicillium chrysogenum, Rhizopus stolonifera, Rhodotorula mucilaginosa and Trichophyton spp. [9,19,43,64].…”

“…There is increasing information that not only polyphenolic compounds, but also essential oil components found in propolis exhibit antimicrobial activity [Ikeda, 2021. It was shown that essential oils from Brazilian propolis contain i.e., camphene, p-cymene, limonene, myrcene, α-pinene, β-pinene [55]. Many studies have proven that these chemical components occurring in essential oils of medicinal plants exerted antifungal activity mainly against Candida albicans [60,[77][78][79].…”

Chemical Variability and Pharmacological Potential of Propolis as a Source for the Development of New Pharmaceutical Products

“…β-Caryophyllene and nerolidol were the predominant compounds of Argentinian green propolis [ 68 ]. α-Pinene and β-pinene were the principal compounds of different samples of the propolis from Brazil [ 18 ]. Limonene was identified as the chemical marker of Venezuelan propolis [ 68 ].…”

“…Among the other organic components are polyphenols and essential oils [ 16 , 17 ]. Flavonoids, phenolic acids, and terpenoids are regarded as the main biologically active substances of propolis [ 14 , 15 , 18 , 19 ]. Okińczyc et al [ 19 ] supposed that the therapeutic effects of propolis are related mainly to the amount of polyphenols and volatile components.…”

Antifungal Activity of Mexican Propolis on Clinical Isolates of Candida Species

“…A natural product recently studied worldwide is propolis, which has shown efficacy against different fungal strains, including Candida sp. [ 5 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 ]. In this sense, it has been reported that propolis samples from different countries such as Poland, Iran, Cameroon, Brazil, the Czech Republic, Ireland, and Germany present both qualitative and quantitative antifungal activity differently in reference Candida strains such as C. albicans (ATCC 10231, 90028, 66396; CBS 562; NR 29450; SC 5314), Candida krusei (ATCC 6258, 90878; CBS 573), Candida parapsilosis (ATCC 22019; CBS 604), and Candida glabrata (CBS 07; DSM 11226; LMA 90-1085), Candida tropicalis (ATCC 9968; CBS 94), and Candida dubliniensis (CBS 7987), and on clinical isolates of Candida obtained from smears of the mouth and throat, as well as fluid from the peritoneal cavity, bronchopulmonary lavage, stoma, blood, urine, feces, and anus, identified as C. albicans , C. glabrata , C. krusei , C. dubliniensis , C. tropicalis , and C. parapsilosis [ 61 , 63 , 64 , 66 , 68 , 69 , 70 , 73 ].…”