Investigations on Ayurvedic medicinal plants towards Inhibition of quorum sensing and biofilm produced by periodontal bacteria isolated from diabetic patients

Periodontitis includes diverse inflammatory circumstances that are common in diabetics and arise due to bacterial biofilms produced by quorum sensing (QS). The current project aims to evaluate the efficacy of certain herbs and formualtions to eradicate biofilms and inhibit quorum sensing of oral pathogens. Plants were extracted with 90% methanol using cold maceration. A primary analysis of extracts was performed using UHPLC and ATR-FTIR. Clinical strains from female diabetic patients were isolated and identified using 16S rRNA. A total of 35 medicinal plants were analyzed and a significant inhibition of Pseudomonas aeruginosa by Syzygium aromaticum oil (IC₅₀ 0.024 mg/ml), Myristica fragrans (seed) (IC₅₀ 0.024 mg/ml) and Juglans regia (root bark) (IC₅₀ 0.048 mg/ml) was recorded. Against Staphylococos aureus a higher inhibition was seen i.e Juglans regia">Juglans regia (IC₅₀ 0.097 mg/ml), Syzygium aromaticum (IC₅₀ 0.024 mg/ml) and Myristica fragrans (IC₅₀ 0.097 mg/ml). Syzygium aromaticum, Myristica fragrans and Juglans regia were active against most tested clinical strains. The clinical strains were found resistant to various antibiotics including ceftriaxone, cephradine, imipenem, meropenem, ofloxacin, amoxicillin, and amoxicillin-clavulanic acid. During antiquorum sensing experiments, the order of QS inhibition was Syzygium aromaticum > Juglans regia ≥ Myristica fragrans. During antibiofilm assays, excellent inhibition was observed for Syzygium aromaticum (72%) and Juglans regia (65%). We are further exploring the plant extracts for isolation of active compounds.