Lotus Seed Extract-Loaded 2% Hyaluronic Acid Gel as a Potential Local Delivery System for Periodontal Application: Antioxidant, Anti-inflammatory, Antibacterial, and In Vitro Release Evaluation

Periodontitis is a chronic inflammatory disease associated with microbial dysbiosis, oxidative stress, and progressive destruction of periodontal tissues. Local drug delivery systems based on biocompatible gels may improve retention of bioactive agents within periodontal pockets and reduce systemic exposure. This study evaluated a lotus seed extract-loaded 2% hyaluronic acid gel as a potential local periodontal formulation. The formulation was assessed for antioxidant activity using the DPPH radical scavenging assay, anti-inflammatory activity using the albumin denaturation inhibition assay, spreadability, antibacterial activity against Porphyromonas gingivalis, and in vitro release behavior over 24 h. Lotus seed extract-loaded HA gel showed concentration-dependent antioxidant activity, with radical scavenging activity increasing from 28.4 ± 0.7% in LSE-HA 25 to 69.7 ± 0.8% in LSE-HA 100. Anti-inflammatory activity also increased in a dose-dependent manner, reaching 79.3 ± 0.8% inhibition at LSE-HA 500. The gel maintained acceptable spreadability, although spreadability decreased from 46.0 ± 0.8 mm in HA gel to 40.2 ± 0.4 mm in LSE-HA 100. Antibacterial testing demonstrated dose-dependent inhibition of P. gingivalis, with LSE-HA 100 producing an inhibition zone of 18.0 ± 0.4 mm compared with 24.1 ± 0.4 mm for chlorhexidine. The release profile demonstrated sustained extract release, reaching 89.3 ± 0.8% cumulative release after 24 h. These findings suggest that lotus seed extract-loaded 2% hyaluronic acid gel may serve as a promising local delivery system for periodontal application by combining antioxidant, anti-inflammatory, antibacterial, and sustained-release properties.