The Application of Mealworm (Tenebrio molitor) Oil in Cosmetic Formulations

The depletion of natural resources, the increasing use of valuable land surface for human activities, and the generation of waste are detrimental to the planet. Sustainable alternatives to guarantee a sufficient supply of food, feed, and biomaterials are needed. Insects may hold an interesting position in a circular economy to tackle contemporary societal challenges. Using insects for food, feed, biomaterial production, and to valorize side-streams, have gained increased interest. Mealworms are amenable to large-scale farming. Herein, the potential of mealworm oil for implementation in a cosmetic hand cream is evaluated. It is shown that mealworms are rich in oil (≈30% of the dry weight), and the oil can be extracted using hexane or ethyl acetate as a solvent. The euthanization step of mealworms has profound effect on the free fatty acid content. The fatty acid profile indicates a large proportion of unsaturated fatty acids, which is promising for use in cosmetic applications. In a proof of concept, the mealworm oil is implemented in a hand cream and compared to hand cream containing macadamia nut oil. No differences in odor and aspect/stability are observed, but mealworm creams are slightly less white color. Mealworm oil is suitable for cosmetics applications. Practical applications: Several insect species can be sustainably reared on low-value organic side-streams, requiring only small amounts of land-surface, less water, and producing less greenhouse gases. In addition, they have short life cycles and can be reared continuously and locally. This implies that insects are an interesting source of biological materials including proteins and oils. Insect oils, including oil of mealworms, have interesting fatty acid profiles that make them amenable to replace oils of vegetable origin for applications within cosmetics. The results indicate that mealworm oil can be a novel, sustainable ingredient for use in the cosmetics industry.     

Molecular Networking for Drug Toxicities Studies: The Case of Hydroxychloroquine in COVID-19 Patients

Using drugs to treat COVID-19 symptoms may induce adverse effects and modify patient outcomes. These adverse events may be further aggravated in obese patients, who often present different illnesses such as metabolic-associated fatty liver disease. In Rennes University Hospital, several drug such as hydroxychloroquine (HCQ) have been used in the clinical trial HARMONICOV to treat COVID-19 patients, including obese patients. The aim of this study is to determine whether HCQ metabolism and hepatotoxicity are worsened in obese patients using an in vivo/in vitro approach. Liquid chromatography high resolution mass spectrometry in combination with untargeted screening and molecular networking were employed to study drug metabolism in vivo (patient’s plasma) and in vitro (HepaRG cells and RPTEC cells). In addition, HepaRG cells model were used to reproduce pathophysiological features of obese patient metabolism, i.e., in the condition of hepatic steatosis. The metabolic signature of HCQ was modified in HepaRG cells cultured under a steatosis condition and a new metabolite was detected (carboxychloroquine). The RPTEC model was found to produce only one metabolite. A higher cytotoxicity of HCQ was observed in HepaRG cells exposed to exogenous fatty acids, while neutral lipid accumulation (steatosis) was further enhanced in these cells. These in vitro data were compared with the biological parameters of 17 COVID-19 patients treated with HCQ included in the HARMONICOV cohort. Overall, our data suggest that steatosis may be a risk factor for altered drug metabolism and possibly toxicity of HCQ.     

Exploring natural products for new taste sensations

This paper discusses the discovery of uncommon taste or trigeminal active compounds and their associated sensory analysis using human tasting panels with the aim of enhancing the overall taste experience whilst reducing where possible the sugar and salt content of foods. The first example outlines the discovery of the sensory quality attributes of (R)-2-(carboxymethylamino)propanoic acid, named (R)-strombine, as assessed by a panel of 47 subjects to confirm its contribution to the typical taste of scallop muscle. The second example discusses the pungency and trigeminal effect of polygodial, which is compared with piperine and capsaicin, as well as the elucidation of a new structure eliciting a trigeminal effect, (+/-)-trans-2,3,3a,7a-tetrahydro-1 H-indene-4-carbaldehyde, discovered in Amomum tsao-ko. Finally, the time intensity trigeminal effect of (-)-menthol is compared with (1R,2RS,4RS)-1-isopropyl-4-methylbicyclo[3.1.0]hexan-2-ol, named dihydroumbellulol, a new cooling compound obtained by hemi-synthesis from umbellulone extracted from Umbellularia californica Nutt.     

The development of a silica nanoparticle-based label-free DNA biosensor

A silica nanoparticle-based DNA biosensor capable of detecting Bacillus anthracis bacteria through the use of unlabelled ss-oligonucleotides has been developed. The biosensor makes use of the optical changes that accompany a nanoparticle-immobilized cationic conjugated polymer (polythiophene) interacting with single-stranded vs. hybridized oligonucleotides, where a fluorescence signal appears only when hybridized DNA is present (i.e. only when the ss-oligonucleotide interacting with the polymer has hybridized with its complement). In order to enhance the sensitivity of the biosensor, two different nanoparticle architectures were developed and used to elucidate how the presence of neighboring fluorophores on the nanoparticle surface affects F?rster-resonant energy transfer (FRET) between the polythiophene/oligonucleotide complex (FRET donor) and the fluorophores (FRET acceptors). We demonstrate that the silica nanoparticle-based FRET platform lowers the limit of detection at least 10-fold in comparison to the polythiophene itself, and allows the detection of ～2 × 10(-12) moles of ss-oligonucleotide in a 100 μL sample with a standard fluorimeter (i.e. has a limit of detection of ～2 nM ssDNA). Such nanoparticle-based biosensor platforms are beneficial because of the robustness and stability inherent to their covalent assembly and they provide a valuable new tool that may allow for the sensitive, label-free detection (the target DNA that produces the fluorescence signal is unlabelled) without the use of polymerase chain reaction.     

Thermal crosslinking of collagen immobilized on poly(acrylic acid) grafted poly(ethylene terephthalate) films

Graft polymerization of acrylic acid onto plasma‐treated poly(ethylene terephthalate) (PET) films was used to prepare surfaces suitable for collagen immobilization by dip‐coating. Such surfaces could be used as matrices for smooth muscle cell cultures in tissue engineering. Contact angle measurements showed that plasma‐treated and grafted PET films undergo considerable surface reorganization during storage under ambient conditions. However, after collagen immobilization the contact angle remained relatively stable. The amount of collagen initially attached to the film surface increased with increasing poly(acrylic acid) graft density, but subsequent washing in water led to significant collagen loss. This loss could nevertheless be substantially reduced by thermal crosslinking of the collagen in the range 110–130 °C. Atomic force microscopy (AFM) observations suggested that the washed crosslinked collagen has a very similar structure to that of the un‐crosslinked collagen. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1874–1880, 2002     

PP/EMA TPV: Dynamic cross‐linking through an alcoholysis reaction

Dynamically cross‐linked polypropylene/ethylene‐methyl acrylate copolymer (PP/EMA) blends were prepared by reactive extrusion in a twin‐screw extruder. A transesterification reaction catalyzed by an organotin compound and involving the acrylic moieties of EMA with the hydroxyl functions of pentanediol was used to cross‐link the elastomeric EMA. The extent of cross‐linking was estimated through the insoluble content of the blend. The alcohol‐to‐acrylic ratio and the dibutyltin oxide content were both found to increase the extent of EMA cross‐linking. Processing conditions such as screw rotation rate and extrusion temperature profile also had large effects on the reaction extent. Conditions leading to improved pentanediol dispersion were found to generate larger insoluble fraction. Gel contents of EMA phase as high as 75% to 85% were obtained. Interestingly, the stress‐strain curves of the cross‐linked PP/EMA TPV are very well represented by a single master curve. Dynamically cross‐linked blends show systematically better tensile properties than the non‐reactive system. Blends with higher insoluble content show strain at break in the 650%–750% range. Material processability was maintained, even for the systems with high insoluble content.     

Interaction between dietary protein and fat in triglyceride metabolism in the rat: Effects of soy protein and menhaden oil

The objective of the present study was to determine the mechanisms by which dietary proteins interact with dietary lipids in the regulation of triglyceridemia in rats. Male Sprague-Dawley rats (n=56) were subjected to 28-d experimental diets containing different combinations of proteins (20% w/w) and lipid sources (14% w/w): (i) casein-menhaden oil, (ii) casein-beef tallow, (iii) soy protein-menhaden oil, and (iv) soy protein-beef tallow. Significant protein-lipid interactions were observed on triglyceridemia and hepatic cholesterol in fasted rats. The combination of casein and beef tallow was associated with high plasma TG and hepatic cholesterol concentrations, which were reduced by substitution either of soy for casein or of menhaden oil for beef tallow. Therefore, triglyceridemia and liver cholesterol remained low with soy protein feeding, independently of the lipid source, as well as with menhaden oil feeding, regardless of the protein source. The menhaden oil diets reduced plasma cholesterol, hepatic TG, and TG secretion compared with beef tallow diets independently of the dietary protein source. Modifying the source of dietary proteins and lipids had no effect on post-heparin plasma lipoprotein lipase activity. These results demonstrate that soy protein can lower rat triglyceridemia relative to casein when associated with beef tallow consumption, whereas menhaden oil can attenuate hypertriglyceridemia when rats are fed casein. The data further suggest that part of the hypotriglyceridemic effect of soy protein in the rat may be mediated by reduced hepatic lipid synthesis, as is the case for menhaden oil.