In Vitro Inhibitory Effect of Faloak Leaf Extract (Sterculia quadrifida R.Br.) against Bacteria Causing Mastitis

Abstract

The use of antibiotics and chemical agents for the treatment and prevention of mastitis contributes to antibacterial resistance and antibiotic residues in milk. Therefore, safe and sustainable alternative materials are required. This study aimed to evaluate the in vitro antibacterial activity of faloak leaf extract against mastitis-causing bacteria. Faloak leaves were macerated using 96% ethanol to obtain a concentrated extract. Flavonoid content was analyzed spectrophotometrically using quercetin as the standard. Antibacterial activity was determined by the disk diffusion method at extract concentrations of 5%, 10%, 20%, 30%, 40%, and 50%, with commercial antibiotics as positive control and distilled water as the negative control. Each treatment was replicated nine times. Data were analyzed using ANOVA followed by Duncan’s Multiple Range Test (DMRT) to determine significant differences. The flavonoid content of the extract was 0.227 ± 0.007 mg/g QE. The extract effectively inhibited the growth of Staphylococcus aureus ATCC 25923 and Escherichia coli FNCC 0091. A 50% concentration showed inhibitory activity comparable to commercial antibiotics against S. aureus, while a 30% concentration demonstrated similar effectiveness against E. coli. Inhibition zone diameter increased with higher extract concentrations. These findings indicate that faloak leaf extract has potential as a natural antibacterial alternative for mastitis prevention in vitro.