Browsing by Author "Eissa, Tarek F."

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Antimicrobial potential of Mentha Spp. essential oils as raw and loaded solid lipid nanoparticles against dental caries
(rjpt, 2020-09) Mostafa, Dalia A; Bayoumi, Faten S.; Taher, Heba M.; Abdelmonem, Basma H.; Eissa, Tarek F.
This study evaluates the antimicrobial potential of Mentha spp. (M.spicata L.,M. xpiperita L. and M. pulegium L.) essential oils as raw and loaded solid lipid nanoparticles (SLNs)against dental caries. Design: Essentials oils extraction from fresh aerial parts of Mentha spp. was carried out using hydro distillation technique. Solid lipid nanoparticles of Mentha essential oil were prepared by w/o/w type double emulsification method. The antimicrobial activity of both pure Mentha spp. essential oils and Mentha spp. SLNs was determined against bacteria presented in saliva collected from 12 patients using agar diffusion assay. Results: Mentha spp. essential oils loaded solid lipid nanoparticles (MSLNs) were spherical shaped with sizes ranged from 111 to 202 nm and with PDI from 0.43 to 0.76, EE% between 85 and 88, and ZP of −11.8 to -40 mV. Antimicrobial results showed that MSLNs exhibited higher in vitro antimicrobial activity than pure Mentha spp. essential oil. Particularly, with an inhibition zone of 20 mm. These both MSLNs were even more active than the reference compound novobiocin. Conclusion: Our findings demonstrate that Mentha spp. essential oils as a nanostructure increase the efficiency of these natural products as antibacterial agents against caries.
A Comparative Metabolomics Approach for Egyptian Mango Fruits Classification Based on UV and UPLC/MS and in Relation to Its Antioxidant Effect
(Multidisciplinary Digital Publishing Institute (MDPI), 2022-07) Farag, Mohamed A; Abdelwareth, Amr; Zayed, Ahmed; Eissa, Tarek F.; Dokalahy, Eric; Frolov, Andrej; Wessjohann, Ludger A
Mango (Mangifera indica L.) is a tropical climacteric fruit that encompasses a myriad of metabolites mediating for its nutritive value, unique taste, flavor, and medicinal uses. Egypt is among the top mango producers worldwide, albeit little characterization has been made toward its fruits’ chemical composition. This study aims to assess metabolites difference via comparative profiling and fingerprinting of Egyptian mango in context to its cultivar (cv.) type and/or growth province. To achieve such goal, hyphenated chromatographic techniques (UPLC/MS) and UV spectroscopy were employed and coupled to multivariate data analysis for Egyptian mango fruits’ classification for the first time. UPLC/MS led to the detection of a total of 47 peaks identified based on their elution times and MS data, belonging to tannins as gallic acid esters, flavonoids, xanthones, phenolic acids and oxylipids. UV/Vis spectra of mango fruits showed similar absorption patterns mostly attributed to the phenolic metabolites, i.e., gallic acid derivatives and phenolic acids showing λmax at ca. 240 and 270 nm. Modeling of both UPLC/MS and UV data sets revealed that cv. effect predominated over geographical origin in fruits segregation. Awees (AS) cv. showed the richest phenolic content and in agreement for its recognition as a premium cv. of mango in Egypt. Results of total phenolic content (TPC) assay revealed that AS was the richest in TPC at 179.1 mg GAE/g extract, while Langara from Ismailia (LI) showed the strongest antioxidant effect at 0.41 mg TE/g extract. Partial least square modeling of UV fingerprint with antioxidant action annotated gallates as potential contributor to antioxidant effect though without identification of exact moieties based on UPLC/MS. The study is considered the first-time investigation of Egyptian mango to aid unravel phytoconstituents responsible for fruits benefits using a metabolomics approach.