The Biological Activity of Monarda didyma L. Essential Oil and Its Effect as a Diet Supplement in Mice and Broiler Chicken

Abstract

The use of growth-promoting antibiotics in livestock faces increasing scrutiny and opposition due to concerns about the increased occurrence of antibiotic-resistant bacteria. Alternative solutions are being sought, and plants of Lamiaceae may provide an alternative to synthetic antibiotics in animal nutrition. In this study, we extracted essential oil from <i>Monarda didyma</i>, a member of the Lamiaceae family. We examined the chemical composition of the essential oil and then evaluated the antibacterial, antioxidant, and anti-inflammatory activities of <i>M. didyma</i> essential oil and its main compounds <i>in vitro</i>. We then evaluated the effectiveness of <i>M. didyma</i> essential oil in regard to growth performance, feed efficiency, and mortality in both mice and broilers. Carvacrol (49.03%) was the dominant compound in the essential oil extracts. <i>M. didyma</i> essential oil demonstrated antibacterial properties against <i>Escherichia coli</i> (MIC = 87 µg·mL^-1), <i>Staphylococcus aureus</i> (MIC = 47 µg·mL^-1), and <i>Clostridium perfringens</i> (MIC = 35 µg·mL^-1). Supplementing the diet of mice with essential oil at a concentration of 0.1% significantly increased body weight (+5.4%) and feed efficiency (+18.85%). In broilers, <i>M. didyma</i> essential oil significantly improved body weight gain (2.64%). Our results suggest that adding <i>M. didyma</i> essential oil to the diet of broilers offers a potential substitute for antibiotic growth promoters.