In silico molecular docking, antimicrobial and anti-inflammatory activities of bioactive fractions of Citrus sinensis (L.) Osbeck. peel against oral pathogens in dental caries

Abstract

Dental caries is the most prevalent oral disease. It is caused by infection of Streptococcus mutans and Candida albicans. It is associated with inflammation of the dental gum. Antimicrobial agents or systemic antibiotics are administered to prevent dental caries. However, the pathogens become drug-resistant to specific antibiotics, so a combinational therapy approach may lead to the management of dental caries. In the current investigation, the peel of Citrus sinensis (L.) Osbeck was evaluated for antimicrobial and anti-inflammatory activities in dental caries. Different fractions of hydroalcohol extract were tested for in vitro antimicrobial activity against S. mutans and C. albicans. Based on the results, methanol fraction was selected for ex-vivo anti-inflammatory activity. The bioactive compounds of the methanol faction were identified by GC-MS. Only selected compounds were subjected to in silico docking analysis towards selective proteins of S. mutans and C. albicans. Amongst all the fractions, the methanol fraction showed significant antimicrobial activity against S. mutans (ZOI, 27 mm; MIC, 0.78 mg/ml; and MBC, 1.56 mg/ml) and C. albicans (ZOI, 29 mm; MIC, 0.39 mg/ml; and MBC, 1.56 mg/ml). Methanol fraction (100 µg/ml) exhibited the highest inhibition of 79.29% than other fractions in the anti-inflammatory study. GC-MS analysis of methanol fraction reported 17 compounds. Out of these, only ten compounds satisfied Lipinski’s rule of five in ADMET analysis and were subjected to in silico docking analysis. The results confirmed that the compounds of methanol fraction have the potential to inhibit the active proteins of dental caries pathogen.