Characterization, Antimicrobial Activity, and Antioxidant Efficacy of a Pomegranate Peel Solution Against Persistent Root Canal Pathogens.

Abstract

The limitations of dental irrigation solutions reinforce the need to explore novel bioactive compounds that are safer and biodegradable. This study aimed to prepare a 10% pomegranate peel solution (Punica granatum extract - PGE) and evaluate its antimicrobial and antioxidant effects forroot canal treatment. Lyophilized extracts (1g/10 mL) from pomegranate peels were prepared, and the punicalagin content was assessed by ultra-performance liquid chromatography using pure punicalagin (standard). The antimicrobial activity was tested against common persistent root canal pathogens by the agar diffusion method, minimum inhibitory concentration (MIC), and minimum bactericidal/fungicide concentration (MCB/MFC). The antioxidant activity (%AA) was assessed by the DPPH radical scavenging method. Data were analyzed by ANOVA and Tukey's test (α = 0.05). The total phenolic content of the PGEextract was 6.55 µg/mL. Differences were found among the inhibition zone of PGE (23.32 ± 3.65), 1% NaOCl (30.76 ± 4.73), and 50% ethanol (without inhibition) (p < 0.05). The MIC values of PGE ranged between 6.25 and 75 mg/ml, and PGE was effective against the tested pathogens. PGE had antioxidant potential (IC50 = 3.52 µg/mL); however, the mean values were inferior to that of the quercetin (positive control) (IC50 = 0.95 µg/mL). The DPPH scavenging effect (%AA) of PGE (70.98 ± 2.3) had no difference from the positive control (72.94 ± 2.1) (p = 0.253). The PGE extract was successfully biosynthesized and exhibited antimicrobial and antioxidant activity, suggesting its potential use as an adjuvant therapy during root canal treatment.