Juglans regia and Pfaffia paniculata extracts: implications for periodontal disease treatment and correlation with Alzheimer’s risk

Abstract

Periodontal disease (PD) is a significant global health concern, affecting approximately 19% of the world's population. It is one of the most prevalent diseases today, causing substantial socio-economic impacts and diminished quality of life. Recent research has also revealed a potential link between PD and Alzheimer's disease. This study investigated the antimicrobial effects of <i>Juglans regia</i> and <i>Pfaffia paniculata</i> extracts against <i>P. endodontalis</i> and <i>P. gingivalis</i>, bacteria that cause PD and are related to Alzheimer's risk. The study also assessed the impact of these extracts on macrophage metabolic activity, pro- and anti-inflammatory cytokine expression, and genotoxicity. The phytochemical analysis of the extract was carried out first. Antimicrobial activity was performed using the M11-A7 protocol (CLSI) for planktonic cultures on monotypic biofilms matured for 168 hours in anaerobiosis. Cell viability analysis was carried out using MTT on mouse macrophages (RAW 264-7), as well as genotoxicity assessment using micronuclei. The anti-inflammatory activity was evaluated using ELISA method, checking the cytokines IL-6, IL-1B, TNF-alpha, IL-17 and IL-10. Phytochemical analysis revealed the presence of Miquelianin, Regiolone and Gallic Acid in <i>J. regia</i> extract. For the <i>P. paniculata</i> extract, we identified the glycosides Pfaffoside C, Pfaffoside A, 3-O-β-D-glycopyranosyl-oleanolic acid and Beta-ecdysone. Antimicrobial activity revealed a MBC of 1.73 for the extract of J. regia and 0.48 for <i>P. paniculata</i> against <i>P. endodontalis</i> and <i>P. gingivalis</i>. All biofilms were reduced by more than 89% after treatment with the extracts for 5 min. Cytotoxicity evaluations revealed that cell viability remained above 50% at concentrations up to 0.216 mg/ml for <i>J. regia</i> and 0.015 mg/ml for <i>P. paniculata</i>. Neither extract exhibited genotoxicity. Furthermore, both demonstrated anti-inflammatory activity by promoting the production of the cytokine IL-10. In conclusion, the antimicrobial and anti-inflammatory activities of <i>J. regia</i> and <i>P. paniculata</i> extracts suggest their potential as treatments for oral dysbiosis, which may contribute to a reduced risk of neurodegenerative diseases.