BACKGROUND AND AIMDental caries, primarily caused by Streptococcus mutans and Lactobacillus spp., is a major global health issue. There is a growing need for effective, natural antimicrobial treatments. Ocimum tenuiflorum and Ocimum gratissimum are known for their medicinal properties, including antimicrobial activity. This study investigates the antibacterial efficacy of a herbal oral rinse derived from these plants. This study aimed to evaluate the antibacterial activity of an herbal formulation-based oral rinse prepared from Ocimum tenuiflorum and Ocimum gratissimum against Streptococcus mutans and Lactobacillus spp.METHODSFresh leaves of Ocimum tenuiflorum and Ocimum gratissimum were shade-dried, powdered, and extracted in distilled water. The extract was incorporated into an oral rinse formulation. The antibacterial activity was assessed using the agar well diffusion method, protein leakage and cytoplasmic leakage assays, and time-kill curve analysis. A commercial oral rinse was used as a standard.RESULTSThe herbal oral rinse exhibited significant antibacterial activity against both Streptococcus mutans and Lactobacillus spp. The zones of inhibition for Streptococcus mutans were 10 mm, 13 mm, and 15 mm at concentrations of 25 µg/mL, 50 µg/mL, and 100 µg/mL, respectively. For Lactobacillus spp., the inhibition zones were 10 mm, 12 mm, and 14 mm at the same concentrations. The protein leakage and cytoplasmic leakage analysis supported these findings, demonstrating the formulation's efficacy at low concentrations. Time-kill curve assays showed rapid bactericidal action, particularly at higher concentrations.CONCLUSIONThe Ocimum tenuiflorum and Ocimum gratissimum-based herbal oral rinse demonstrates strong antibacterial activity against key oral pathogens, suggesting that it could be a natural alternative to conventional oral rinses.