Validating the protective role of orange and tangerine peel extracts foramending food safety against microorganisms' contamination using molecular docking

Latest studies indicated that agro-food wastes are considered renewable sources of bioactive compounds. This investigation aimed to utilize natural extracts of citrus peels as antimicrobial and anti-aflatoxigenic agents for food safety. The bioactivity of two citrus peels was assessed by total phenolic, flavonoids, and antioxidant activity. Nanoemulsions were manufactured using high-speed homogenization. The mean particle size of the nanoemulsions ranged from 29.41 to 66.41 nm with a polydispersity index of 0.11-0.16. The zeta potential values ranged from -14.27 to -26.74 mV, indicating stability between 81.44% and 99.26%. The orange peel extract showed the highest contents of total phenolic and flavonoids compared to the other extracts and nanoemulsions (39.54 mg GAE/g and 79.54 mg CE/100 g, respectively), which agreed with its potential antioxidant activity performed by DPPH free radical-scavenging and ABTS assays. Chlorogenic, caffeic, ferulic, and catechin were the dominant phenolic acids in the extracts and nanoemulsions, while quercitrin, rutin, and hesperidin were the most abundant flavonoids. Limonene was the major volatile component in both oils; however, it was reduced dramatically from 92.52% to 76.62% in orange peel oil and from 91.79 to 79.12% in tangerine peel oil. Consistent with the differences in phenolics, flavonoids, and volatiles between orange and tangerine peel extracts, the antibacterial properties of orange extracts had more potential than tangerine ones. Gram-positive bacteria were more affected by all the examined extracts than Gram-negative ones. The antifungal activity of orange extract and nanoemulsion on seven fungal strains from Aspergillus spp had more potential than tangerine extracts. Additionally, using a simulated media, the orange peel extract and its nanoemulsion had a more anti-aflatoxigenic influence. Molecular docking confirmed the high inhibitory action of flavonoids, especially hesperidin, on the polyketide synthase (-9.3 kcal/mol) and cytochrome P450 monooxygenase (-10.1 kcal/mol) key enzymes of the aflatoxin biosynthetic mechanism.

Isolation, Biological Evaluation, and Molecular Docking Studies of Compounds from Sophora mollis (Royle) Graham Ex Baker

The Sophora mollis is one of the best anti-inflammatory, antioxidant, and anticancerous plant; therefore, the isolated chemical constituents, that is, scopoletin (1), pinitol (2), 2-propenoic acid, 3-(3,4-dihydroxyphenyl)-octacosyl ester (3), betulin (4), and β-sitosterol glucoside (5) were tested for these folklores. The structures of the isolated compounds were confirmed by ¹H NMR, ¹³C NMR, 2D-NMR, and mass spectral data. The anti-inflammatory, anticancer, antiglycation, and antioxidant activities of compounds 1-5 were evaluated using different assays. Compound 1 exhibited significant anti-inflammatory effect as it reduced edema of the paw (83.98%), which is more potent than the standard drug (ibuprofen) (which showed an inhibition percentage of 73.22% a), followed by compound 3. Furthermore, compound 3 showed significant free-radical scavenging activity using the 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) free-radical assay. Percentage inhibition of DPPH recorded was 95.646 ± 0.003, 94.766 ± 0.014, and 94.516 ± 0.011% at concentrations of 400, 200, and 100 μg/mL, respectively. Evaluation of anticancer activity of isolated compounds reveals weak effect against HeLa and 3T3 cell lines. Docking studies of the most active compound into the binding sites of cyclooxygenase isoforms showed a better antagonistic potential against COX-1 than the COX-2 isoform.

A new dendrimer series: synthesis, free radical scavenging and protein binding studies

Tri-o-tolyl benzene-1,3,5-tricarboxylate (TOBT (T0)), tri-4-hydroxyphenyl benzene-1,3,5-tricarboxylate (THBT (T1)), and tri-3,5-dihydroxyphenyl benzene-1,3,5-tricarboxylate (TDBT (T2)), a series of 1^st tier dendrimers with a common 1,3,5-benzenetricarbonyl trichloride/trimesoyl chloride (TMC) core, are reported. T0 does not have any replaceable H⁺ on its terminal phenyl group, acting as a branch. T1 has one phenolic –OH at the para position and T2 has two phenolic –OH groups at the 3 and 5 positions of each terminal phenyl group. During synthesis, these –OH groups at the terminal phenyl groups were protected through tert-butyldimethylsilyl chloride (TBDMSCl) assisted with t-BuOK in DCM, THF, indazole, 4-dimethylaminopyridine (DMAP), and tertiary-n-butyl ammonium fluoride (TBAF). MTBDMSP (mono-tertiary butyl dimethylsilane phloroglucinol), DTBDMSP (di-tertiary butyl dimethylsilane phloroglucinol), and TTBDMSP (tri-tertiary butyl dimethylsilane phloroglucinol) were obtained with >90% yield, and TTBDMSP phenolic derivatives (PDs) were developed to synthesize T0, T1, and T2 dendrimers by deprotecting with TBAF. T0 showed superhydrophobic properties as it did not dissolve in methanol, contrary to T1 and T2, but dissolved in acetone. Their structures were determined using ¹H and ¹³C NMR spectroscopies, and mass spectrometry. Their scavenging activities were studied using UV-Vis spectrophotometry compared with ascorbic acid and protein binding was studied with bovine serum albumin (BSA) and lysozyme (lyso). T0 exhibited exceptional optical activity contrary to T1 and T2, which acted as antioxidants to scavenge free radicals.

Superhydrophobic dendrimers with excellent antioxidant properties, and the ability to bind proteins and enzymes in their functional void spaces.

Cationic Surfactants: Self-Assembly, Structure-Activity Correlation and Their Biological Applications

The development of biotechnological protocols based on cationic surfactants is a modern trend focusing on the fabrication of antimicrobial and bioimaging agents, supramolecular catalysts, stabilizers of nanoparticles, and especially drug and gene nanocarriers. The main emphasis given to the design of novel ecologically friendly and biocompatible cationic surfactants makes it possible to avoid the drawbacks of nanoformulations preventing their entry to clinical trials. To solve the problem of toxicity various ways are proposed, including the use of mixed composition with nontoxic nonionic surfactants and/or hydrotropic agents, design of amphiphilic compounds bearing natural or cleavable fragments. Essential advantages of cationic surfactants are the structural diversity of their head groups allowing of chemical modification and introduction of desirable moiety to answer the green chemistry criteria. The latter can be exemplified by the design of novel families of ecological friendly cleavable surfactants, with improved biodegradability, amphiphiles with natural fragments, and geminis with low aggregation threshold. Importantly, the development of amphiphilic nanocarriers for drug delivery allows understanding the correlation between the chemical structure of surfactants, their aggregation behavior, and their functional activity. This review focuses on several aspects related to the synthesis of innovative cationic surfactants and their broad biological applications including antimicrobial activity, solubilization of hydrophobic drugs, complexation with DNA, and catalytic effect toward important biochemical reaction.

Curcumin Encapsulation in Multilayer Oil-in-Water Emulsion: Synthesis Using Ultrasonication and Studies on Stability and Antioxidant and Release Activities

Curcumin is a natural polyphenol compound obtained from the turmeric plant, having numerous promising health benefits. To deliver curcumin into the human body, it is necessary to develop an efficient carrier system for its encapsulation such that the physicochemical properties of curcumin can be preserved during storage. In this study, the encapsulation stability, antioxidant activity, and release properties of curcumin encapsulated in the primary emulsion (PE: 0.0022% (w/w) curcumin, 9.99% (w/w) oil, 0.9% (w/w) whey protein isolate, pH 7) and secondary emulsion (SE: 0.00108% (w/w) curcumin, 4.90% (w/w) oil, 0.443% (w/w) WPI, 0.2% (w/w) sodium alginate, pH 5) prepared using ultrasonication were analyzed. It was observed that the formation of a double-layer coating of secondary biopolymer over the primary coated droplet enhanced the encapsulation efficiency and antioxidant activity of the curcumin during storage for 3 weeks. Moreover, the multilayer emulsions were freeze-dried to see the effect of dehydration of emulsion on the stability of multilayer-coated droplets. Fourier transform infrared analysis indicated the presence of all of the constituents, including curcumin, after the freeze drying of the emulsions. Scanning electron microscopy images showed that the microstructure of emulsion droplets was found to be uniformly distributed in the case of SE. The antioxidant activity of curcumin encapsulated in SE was found to be higher during storage, whereas it was significantly reduced in other encapsulated systems like PE, olive oil, and ethanol. In vitro release of curcumin from the multilayer emulsion was carried out under the simulated intestinal conditions of pancreatin enzyme and bile salt. Maximum releases of 71 and 63% were obtained in SE and PE, respectively, within 2 h of digestion. Overall, this study provides useful information on the formation of multilayer emulsion as a carrier system for the better protection and release of curcumin useful for food and pharmaceutical applications.

Philic-phobic chemical dynamics of a 1st tier dendrimer dispersed o/w nanoemulsion

Olive, castor and linseed oil (oil-in-water) nanoemulsions were prepared using Tween-20, sodium dodecyl sulfate, and cetyltrimethylammonium bromide (0.12 w/w%) with 0.02 w/w% cellulose acetate propionate (CAP), 0.02 w/w% cellulose acetate butyrate (CAB), 6.2 w/w% ethyl acetate, 5.5 w/w% ethanol and 7.8 w/w% glycerol as dispersion agents. To study the dispersion effect of trimesoyl 1,3,5-tridimethyl malonate (TTDMM, 1st tier), nanoemulsions were prepared with olive, castor and linseed oil. Their density, viscosity, surface tension and friccohesity measurements at T = (293.15, 303.15, and 315.15) K, hydrodynamic radii, surface excess concentration, surface area per molecule, and antioxidant activities were studied. Dispersion variations of TTDMM on varying surfactant and specific interactions of the hydration spheres and ester moiety of TTDMM with ethyl acetate, ethanol and glycerol linked oil-water-surfactant networks have been established. The variations in physicochemical properties suggest that the oil-TTDMM interaction abilities of the surfactant and co-surfactant moieties in the nanoemulsions cause a hydrophobic segregation. The physicochemical study of both blank and TTDMM loaded nanoemulsions have illustrated the thermodynamic stabilities in terms of hydrophobic-hydrophilic, hydrophilic-hydrophilic, van der Waals and hydrogen bonding interactions.

Chemical composition and in vitro anticancer, antimicrobial and antioxidant activities of essential oil and methanol extract from Rumex nervosus

Chemical composition, antioxidant, anticancer, and antimacrobial activities of essential oil obtained from leaves of Rumex nervosus has been evaluated here for the first time. GC/MS analysis reveals the presence of Palmitoleic Acid (28.35%) and Palmitic acid, (25. 37%) as their methyl ester as major components. The essential oil showed significant DPPH radical scavenging activity (94.907 ± 0.1089% and 94.003 ± 0.0749%) at concentration (100 and 80) μg/mL respectively. The oil showed promising activity against staph aureus, while showed weak activity against (Hela and 3T3) cell lines. The crude extract / fractions of R. nervosus (leaves) showed significant antioxidant activity at dose (100 and 80) μg/mL. Futhermore the crude showed significant activity against (MCF-7 and MDA-MB-231) cell lines with IC₅₀ (20.5138 ± 0.933 and 25.1728 ± 0.9176) μg/mL respectively, and chloroform fraction showed good activity against (MCF-7 and MDA-MB-231) cell lines with IC₅₀ (31.154 ± 0.965 and 42.269 ± 2.1045) μg/mL.

Cytotoxicity Evaluation of Turmeric Extract Incorporated Oil-in-Water Nanoemulsion

To overcome the drawbacks of conventional drug delivery system, nanoemulsion have been developed as an advanced form for improving the delivery of active ingredients. However, safety evaluation is crucial during the development stage before the commercialization. Therefore, the aim of this study was to evaluate the cytotoxicity of two types of newly developed nanoemulsions. Turmeric extract-loaded nanoemulsion powder-10.6 (TE-NEP-10.6, high content of artificial surfactant Tween 80), which forms the optimal nanoemulsion, and the TE-NEP-8.6 made by increasing the content of natural emulsifier (lecithin) to reduce the potential toxicity of nanoemulsion were cultured with various cells (NIH3T3, H9C2, HepG2, hCPC, and hEPC) and the changes of each cell were observed followed by nanoemulsion treatment. As a result, the two nanoemulsions (TE-NEP-10.6 and TE-NEP-8.6) did not show significant difference in cell viability. In the case of cell line (NIH3T3, H9C2, and HepG2), toxicity was not observed at an experimental concentration of less than 1 mg/mL, however, the cell survival rate decreased in a concentration dependent manner in the case of primary cultured cells. These results from our study can be used as a basic data to confirm the cell type dependent toxicity of nanoemulsion.