Inhibitory Effect of Canavalia gladiata Extract on Aggregatibacter actinomycetemcomitans LPS Induced Nitric Oxide in Macrophages

Objectives: Canavalia gladiata (Jacq.) DC. (C. gladiata) has been used in traditional medicine to treat suppurative inflammatory conditions. Its antibacterial activity against oral pathogens and potential use as a non-alcoholic mouthwash have also been reported. This study aimed to elucidate the biological activity of Con A from C. gladiata, evaluate nitric oxide (NO) production induced by Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), and as-sess its potential association with periodontal inflammation. Methods: In this study, a 0.5 M NaCl extract of C. gladiata (CGE_Na) was prepared, and its protein content was quantified. The Concanavalin A equivalent (Con Aeq.) of CGE_Na was determined via a hemagglutination assay, and its effect on NO production was evaluated in RAW 264.7 macrophages stimulated with lipopolysaccharide (LPS-A.a.) derived from A. actinomycetemcomitans. LPS was extracted from six A. actinomycetemcomitans strains and used to induce inflammatory activation. Result: CGE_Na treatment significantly inhibited LPS-induced NO production at concentrations below 6.25 μg/mL without cytotoxic effects, suggesting an anti-inflammatory potential associated with lectin-like components. Conclusions: These results suggest that C. gladiata extract suppresses LPS-A.a.-mediated macrophage activation. Further studies are required to determine whether Con A specifically mediates this response and to evaluate its therapeutic relevance in the context of periodontal inflammation.