Phenol-rich alternatives for Rosa x damascena Mill. Efficient phytochemical profiling using different extraction methods and colorimetric assays

Damask rose is a well-established, abundant source of phytochemicals, as well as economically important essential oil—however, its cultivation is demanding and costly. In this paper, extracts from four raw plant materials—Salvia officinalis, Sambucus nigra, Matricaria chamomilla, Calendula officinalis, known to be rich in phenolic compounds, but also far easier to cultivate—were directly compared to those obtained from Rosa × damascena Mill. By combining diverse extraction methodologies (in a Soxhlet apparatus, ultrawave-assisted and microwave-assisted, using supercritical CO2) and complementary in vitro assays (radical scavenging, iron reducing, Folin–Ciocalteau and Al3+ complexation), it was possible to conveniently approximate and compare the phytochemical portfolios of those diverse plants. By factoring in the crop yields of different species, economically important conclusions can be reached—with pot marigold (C. officinalis) seemingly the most viable substitute for damask rose as a source of phenolics. Fatty acid and microelement analyses were also performed, to further enrich the chemical profiles of plant extracts. The paper also aims to collate and redesign multiple colorimetric assays frequently used while studying plant extracts in vitro, but criticized for their lack of correlation to in vivo activity. We show that they remain a viable tool for direct comparison of extraction methodologies, while highlighting their shortcomings.

Further Micro-scaled MEDI (Macronutrient Extraction and Determination from Invertebrates) v1

Macronutrients, comprising carbohydrates, proteins and lipids, underpin many ecological processes, but their quantification in ecological studies is often inaccurate and laborious, requiring large investments of time and bulk samples, which make individual‐level studies impossible. This is a protocol for the direct, rapid and relatively low‐cost determination of macronutrient content from single small macroinvertebrates. Macronutrients are extracted by a sequential process of soaking in 1:12 chloroform:methanol solution to remove lipid and then solubilising tissue in 0.1 M NaOH. Proteins, carbohydrates and lipids were determined by colorimetric assays from the same individual specimens. Macronutrient Extraction and Determination from Invertebrates (MEDI) can directly and rapidly determine macronutrient content in tiny (dry mass <1 mg). Using MEDI, the total macronutrient content of over 50 macroinvertebrates can be determined within around 3 days of collection at a cost of ~$1.35 per sample.

Is a Stop Solution Necessary for Metal Nanoparticles Aggregation-based Colorimetric Assays?

We report herein for the first time that a stop solution should be used to terminate the metal nanoparticles aggregation reactions especially salt-induced ones to increase the repeatability of the assays. It was found that hydrophobic surfactants have the ability to slow down the aggregation process of MNPs and can be applied as stop solution for aggregation based colorimetric assays. This trick provides accurate and well-repeatable signals since the aggregation of the nanoparticles is a dynamic process and capturing signal in a predetermined time is difficult.

Discovery of Diagnostic and Therapeutic Targets For Vascular Injury Induced By Methylglyoxal Using Proteomics

Background: Methylglyoxal, a byproduct of diabetes or the consumption of a high-carbohydrate diet, is associated with vascular injury; however, its molecular mechanisms remain unclear. We aimed to systematically characterize molecular profiles and offer unique insights into new disease pathways, thereby contributing to understanding the mechanisms and pathogenesis of vascular injury-related cardiovascular diseases. Methods: Cell survival assays were performed to assess DNA damage; oxidative stress was confirmed by colorimetric assays and quantitative fluorescence, and cyclooxygenase-2 and the mitogen-activated protein kinase pathways were assessed using ELISA. Differentially expressed proteins were quantitated via TMT-based LC-MS/MS and bioinformatics analysis, and confirmed by parallel reaction monitoring. Results: Vascular injury was assessed through colorimetric assays, quantitative fluorescence, ELISA, and survival assays. Of the 4029 proteins identified, 368 were differentially expressed after methylglyoxal treatment, compared with the negative control; 31 were defined as biomarkers or therapeutic targets according to the Gene Ontology Program, Kyoto Encyclopedia of Genes and Genomes, and protein-protein interaction network analyses. Sixteen proteins were significantly (p<0.05) upregulated (>1.5-fold change) and 15 were dramatically downregulated (<0.667-fold change) and confirmed through parallel reaction monitoring.Conclusions: The 31 proteins identified as biomarkers or therapeutic targets may contribute to vascular dysfunction through DNA damage, oxidative stress, inflammation, autophagy, hypertension, endothelial dysfunction, vascular remodeling, and the coagulation cascade. Additionally, new disease pathways involving the Wnt, ErBb, and BMP signaling pathways were identified; all provide scope as potential underlying molecular mechanisms. Therefore, the 31 proteins identified warrant further development as new therapeutic or diagnostic targets for vascular diseases.