ANTIMICROBIAL ACTIVITY OF BACCHARIS SALICIFOLIA AND B. SPARTIODES ESSENTIAL OILS

ARIZA SAMPIETRO, M.B.; LÓPEZ SANDRA; PESCHIUTTA, MARIA L.; CORTEZ TORNELLO PABLO; ALEJANDRO A. TAPIA; LIMA, BEATRIZ

SAN JUAN

Congreso; XLI REUNION CIENTIFICA ANUAL DE LA SOCIEDAD DE BIOLOGIA DE CUYO; 2023

Essential oils (EOs) are presented as a promising antimicrobial alternative to natural products. Previously, the genus Baccharis has been reported as a potential insecticide against mosquitoes and flies, mainly against A. aegypti, Culex sp. and flies of the family Calliphoridae. Some terpenoid compounds from essential oils such as β-pinene, d-limonene, E-nerolidol and α-pinene have shown significant activity in insect metabolism. Previous work developed by the authors allowed the selection of the Baccharis salicifolia species; B. spartiodes that were found to have potential repellent activity against Triatoma infestans “vinchucas”. In order to continue investigating the properties of bioactive compounds, EOs were evaluated as possible antimicrobials. This study aimed to determine the antibacterial and antifungal properties of EOs from Baccharis salicifolia and B. spartiodes aerial parts collected in San Juan, Argentina, during the flowering period 2022-2023. The EOs were hydrodistilled in a Clevenger type apparatus, according to the method recommended by the European Pharmacopoeia and characterized by GC-FID and GC/MS analysis. The antimicrobial effects were evaluated by the CLSI protocols, 2008 and 2015. The commercial standards Imipecil and ketoconazole were used as negative controls. The chemical composition of the EO of B. salicifolia showed a high content of monoterpenic hydrocarbons, approximately 30%, of which 21% is represented by α-pinene, the other major compound is spathulenol (14.4%), an oxygenated sesquiterpene. The EO of B. spartioides presented a composition dominated by the monoterpenic hydrocarbons α-phellandrene (40.5%), sabinene (22.7%) and α-pinene (12.0%), which together represented more than 80% of the total identified (98.0% ) coincident with what was published. Regarding the antibacterial activity, the EO of Baccharis salicifolia; showed activity against the bacteria typed Gram + Staphylococcus aureus methicillin-resistant ATCC 43300, S. aureus methicillin-sensitive ATCC 25923 and Gram – Escherichia coli ATCC 25922 (MIC= 1000 μg/ml), while the AE of B. spartioides showed moderate activity (MIC ≥ 2000 μg/ml). With respect to yeast fungi, Candida albicans, C. parapsilosis, clinical isolates of C. tropicalis C131 and C. tropicalis MQ1 and Cryptococcus neoformans from the Marcial Quiroga Hospital of San Juan, Argentina were found moderately sensitive to both EOs (MIC = 750 µg/ml).The essential oils of B. salicifolia and B. spartiodes are a natural alternative to combat microbial resistanc.