Characterization and Antimicrobial Activity of <i>Nigella sativa</i> Extracts Encapsulated in Hydroxyapatite Sodium Silicate Glass Composite

Abstract

N. sativa is an interesting source of bioactive compounds commonly used for various therapeutic purposes. Associate its seeds extracts with biomaterials to improve their antimicrobial properties are highly demanded. This study aims to investigate the encapsulation of NS extracts in hydroxyapatite nanoparticle sodium silicate glass (nHap/SSG) scaffold. NS essential oil (HS) was extracted by hydrodistillation, while hexane (FH) and acetone extracts (FA) were obtained using Soxhlet extraction. (FH) was the most abundant (34%) followed by (FA) (2.02%) and (HS) (1.2%). GC-MS chromatography showed that the (HS) contained beta cymene, alpha thujene, β-pinene and thymoquinone, while (FH) had mostly fatty acids and (FA) decane, 2.9-dimethyl, benzene 1,3,3-trimethylnonyl and beta cymene. Loaded nHap/SGG scaffolds with various amount of (FH), (HS) and (FA) at 1.5, 3, and 6 wt%; were elaborated then characterized by ATR-FTIR, X-ray and SEM techniques and their antimicrobial activity was studied. Samples loaded with 1.5 wt% HE was highly active against C. albicans (19 mm), and at 3 wt% on M. luteus (20 mm) and S. aureus (20 mm). Additionally, loaded scaffolds with 1.5 wt% AE had an important activity against M. luteus (18.9 mm) and S. aureus (19 mm), while the EO had low activities on all bacterial strains. The outcome of this finding indicated that loaded scaffolds demonstrated an important antimicrobial effect that make them promising materials for a wide range of medical applications.

Keywords

• <i>Nigella sativa</i> L.
• composite scaffold
• hydroxyapatite
• antimicrobial activity