Potencial terapêutico de extratos de Cannabis Sativa no controle de patógenos intramamários

Abstract

Mastitis is one of the main diseases affecting dairy production, frequently associated with bacteria of the genus Staphylococcus and aggravated by increasing antimicrobial resistance. In this context, the in vitro antimicrobial activity of Cannabis sativa extracts was evaluated against strains of Staphylococcus aureus (bovine and caprine), Staphylococcus chromogenes (bovine), and Staphylococcus caprae (caprine), isolated from herds in the state of Paraíba, Brazil. The assay was performed using the disk diffusion method (Kirby–Bauer), employing extracts rich in cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC), isolated cannabigerol (CBG), and their combinations (CBD:CBG, THC:CBG, THC:CBD). The extracts were initially diluted in dimethyl sulfoxide (DMSO) to obtain a concentration of 30 mg/mL and subsequently diluted in phosphate-buffered saline (PBS) to reach 3 mg/mL. Serial dilutions at a 1:3 ratio were then performed, resulting in concentrations ranging from 3.0 to 0.01 mg/mL, with inhibition zone readings taken at 6, 12, 24, and 48 hours. A concentration- and time-dependent effect was observed, with a significant increase in antimicrobial activity after 12 hours, followed by stabilization, and optimal activity at concentrations above 1.0 mg/mL. Among the treatments, the CBD:CBG combination showed the highest mean inhibition zone, outperforming the isolated extracts. Bovine-origin strains demonstrated greater susceptibility compared to caprine strains, with S. caprae showing the highest resistance profile. It can be concluded that phytocannabinoids, particularly in combined formulations and at concentrations ≥ 1.0 mg/mL, exhibit promising antimicrobial potential against staphylococci associated with mastitis, indicating possible future application as alternative or adjunct therapeutic agents.