A new analytical concept based on chemistry and toxicology for herbal extracts analysis: From phenolic composition to bioactivity

Skin- and Eco-Friendly Hand Sanitizer: A Novel Composition of Natural Extracts to Prevent the Spread of Respiratory Viruses

Respiratory diseases caused by viruses are a serious global health threat. Although the use of hand sanitizers containing alcohol and synthetic antiseptic agents is recognized as an effective, simple, and low-cost measure to combat viral transmission, they can harm human health and the environment. Thus, this work aimed to study the efficacy of combining Camellia sinensis and Chamomilla recutita extracts in a skin- and eco-friendly leave-on hand sanitizer to prevent the spread of respiratory viruses. An oil-in-water emulsion containing C. recutita oily extract (5.0%), C. recutita glycolic extract (0.2%) and C. sinensis glycolic extract (5.0%) showed virucidal activity against HAdV-2 (respiratory virus) and two surrogate viruses of SARS-CoV-2 (HSV-1 and MVH-3), showing great potential to prevent the spread of respiratory viruses. These natural extracts combined are also promising to combat a broad spectrum of other viruses, in the form of antiseptic mouthwashes or throat sprays, surface disinfectants, and veterinary products, among others. Complementally, the developed hand sanitizer demonstrated efficacy against bacteria and fungus.

Next-generation analytical platforms for antioxidant capacity assessment: The urge for realistic and physiologically relevant methods

Bioactive compounds, such as carotenoids, alkaloids, and phenolics, are well known because of their alleged health benefits when consumed regularly in a balanced healthy diet. Some well-documented bioactivities are antioxidant, antihypertensive, antihyperglycemic, antilipidemic, anti-obesity, anti-inflammatory, and antimicrobial capacities. Trying to associate the chemical composition of distinct sources and their bioactivity using in vitro methods, several assays have been developed, implemented, and optimised to recapitulate human physiological conditions. However, in most cases, pitfalls are apparent, and no single test tube-based assay can predict in vivo responses. The need for a more physiologically relevant cell-based method to evaluate the antioxidant capacity of putative antioxidants is apparent. Therefore, in this Review, the current state-of-the-art in food science and nutrition is aligned with cell biology/bioengineering approaches to propose combining in vitro digestion and absorption to obtain a bioavailable fraction containing antioxidants. Overall, human plasma, 2-dimensional human cell lines, such as erythrocytes, lymphocytes, hepatocytes, enterocytes and, ultimately, 3-dimensional spheroids (organoids) could be used as biologically relevant models to assess the antioxidant activity of compounds, foods, and nutraceuticals. This versatile approach is deemed suitable, accurate, reproducible, and physiologically relevant to evaluate the protective effects of antioxidants against ROS-mediated oxidation in vitro.

Conceptual functional-by-design optimisation of the antioxidant capacity of trans-resveratrol, quercetin, and chlorogenic acid: Application in a functional tea

Designing functional foods as delivery systemsmay become a tailored strategy to decrease the risk of noncommunicable diseases. Therefore, this work aims to optimise a combination of t-resveratrol (RES), chlorogenic acid (CHA), and quercetin (QUE) based on antioxidant assays and develop a functional tea formulation enriched with the optimal polyphenol combination (OPM). Experimental results showed that the antioxidant capacity of these compounds is assay- and compound-dependent. A mixture containing 73% RES and 27% QUE maximised the hydroxyl radical scavenging activity and FRAP. OPM upregulated the gene expressions of heme oxygenase-1, superoxide dismutase, and catalase and decreased the reactive oxygen species generation in L929 fibroblasts. Adding OPM (100 mg/L)to a chamomile tea increased FRAP:39%, DPPH:59%; total phenolic content: 57%, iron reducing capacity: 41%, human plasma protection against oxidation: 67%. However, pasteurisation (63 °C/30 min) decreased onlythe DPPH. Combining technology, engineering, and cell biology was effective for functional tea design.

Rooibos (Aspalathus linearis) and its constituent quercetin can suppress ovarian cell functions and their response to FSH

Rooibos (Aspalathus linearis Brum. f) can directly influence female reproduction, but whether rooibos can influence the response of ovarian cells to FSH and whether the rooibos effects are due to the presence of quercetin remain unknown. We compared the influence of rooibos extract and quercetin (both at 10 µg/ml-1) on porcine ovarian granulosa cells cultured with and without FSH (0, 1, 10 or 100 ng/ml-1). The expression of intracellular proliferation (PCNA, cyclin B1) and apoptosis (bax, caspase 3) markers in the cells was detected by immunocytochemistry. The release of progesterone (P), testosterone (T) and estradiol (E) were evaluated with ELISAs. Administration of both rooibos and quercetin reduced the accumulation of proliferation markers and promoted the accumulation of apoptosis markers and the release of T and E. Rooibos stimulated, but quercetin inhibited, P output. Administration of FSH increased the accumulation of proliferation markers, decreased the accumulation of apoptosis markers, promoted the release of P and T, and had a biphasic effect on E output. The addition of both rooibos and quercetin mitigated or prevented the main effects of FSH. The present observations suggest a direct influence of both rooibos and quercetin on basic ovarian functions - proliferation, apoptosis, steroidogenesis and response to FSH. The similarity in the major effects of rooibos and its constituent quercetin indicates that quercetin could be the molecule responsible for the main rooibos effects on the ovary. The potential anti-reproductive effects of rooibos and rooibos constituent quercetin, should be taken into account in animal and human nutrition.

Sustainable and effective approach to recover antioxidant compounds from purple tea (Camellia sinensis var. assamica cv. Zijuan) leaves

Camellia sinensis var. assamica cv. Zijuan (purple tea) is known for its content of anthocyanins, flavan-3-ols, and bioactivities. This study aimed to verify the influence of solvent polarity, in a solid-liquid extraction, on the content of phenolic compounds and chlorophylls, instrumental color, and antioxidant activity. Different proportions of water and ethanol (0:100, 25:75, 50:50, 75:25, and 100:0 v/v) were used for extraction. The results showed that the hydroalcoholic extract (75 % ethanol + 25 % water) had the highest contents of total flavonoids, total anthocyanins, chlorophyll A, and total carotenoids, as well as presenting the highest color intensity, proportion of yellow pigments, and antioxidant activity (total reducing capacity and scavenging of the DPPH free radical). Twenty-two compounds were identified, with chlorogenic acid, hesperidin, (-)-epicatechin, (-)-epigallocatechin gallate, and isoquercitrin being the main phenolics. This phenolic-rich extract inhibited lipoperoxidation induced in egg yolk homogenate (IC₅₀ = 455 mg/L), showed no hemolytic behavior when human erythrocytes were subjected to osmotic stress, and exerted in vitro cytotoxic effects against cancer and hybrid cells. The extract obtained with the mixture of non-toxic solvents presented critical bioactivities, as well as a comprehensive identification of phenolic compounds in the cultivar, and has potential to be used in technological applications.

Comparison of Antioxidant Capacity and Network Pharmacology of Phloretin and Phlorizin against Neuroinflammation in Traumatic Brain Injury

Neuroinflammation is a hallmark of traumatic brain injury (TBI)'s acute and chronic phases. Despite the medical and scientific advances in recent years, there is still no effective treatment that mitigates the oxidative and inflammatory damage that affects neurons and glial cells. Therefore, searching for compounds with a broader spectrum of action that can regulate various inflammatory signaling pathways is of clinical interest. In this study, we determined not only the in vitro antioxidant capacity of apple pomace phenolics, namely, phlorizin and its metabolite, phloretin, but we also hypothesize that the use of these bioactive molecules may have potential use in TBI. We explored the antioxidant effects of both compounds in vitro (DPPH, iron-reducing capacity (IRC), and Folin-Ciocalteu reducing capacity (FCRC)), and using network pharmacology, we investigated the proteins involved in their protective effects in TBI. Our results showed that the antioxidant properties of phloretin were superior to those of phlorizin in the DPPH (12.95 vs. 3.52 mg ascorbic acid equivalent (AAE)/L), FCRC (86.73 vs. 73.69 mg gallic acid equivalent (GAE)/L), and iron-reducing capacity (1.15 vs. 0.88 mg GAE/L) assays. Next, we examined the molecular signature of both compounds and found 11 proteins in common to be regulated by them and involved in TBI. Meta-analysis and GO functional enrichment demonstrated their implication in matrix metalloproteinases, p53 signaling, and cell secretion/transport. Using MCODE and Pearson's correlation analysis, a subcluster was generated. We identified ESR1 (estrogen receptor alpha) as a critical cellular hub being regulated by both compounds and with potential therapeutic use in TBI. In conclusion, our study suggests that because of their vast antioxidant effects, probably acting on estrogen receptors, phloretin and phlorizin may be repurposed for TBI treatment due to their ease of obtaining and low cost.

Seed Phytochemical Profiling of Three Olive Cultivars, Antioxidant Capacity, Enzymatic Inhibition, and Effects on Human Neuroblastoma Cells (SH-SY5Y)

This work evaluated the phytochemical composition of olive seed extracts from different cultivars (‘Cobrançosa’, ‘Galega’, and ’Picual’) and their antioxidant capacity. In addition, it also appraised their potential antineurodegenerative properties on the basis of their ability to inhibit enzymes associated with neurodegenerative diseases: acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and tyrosinase (TYR). To achieve this goal, the phenolic composition of the extracts was determined through high-performance liquid chromatography coupled with photodiode-array detection and electrospray ionization/ion trap mass spectrometry (HPLC-DAD-ESI/MSⁿ). The antioxidant capacity was assessed by two different methods (ABTS^•+ and DPPH^•), and the antineurodegenerative potential by the capacity of these extracts to inhibit the aforementioned related enzymes. The results showed that seed extracts presented a high content of phenolic compounds and a remarkable ability to scavenge ABTS^•+ and DPPH^•. Tyrosol, rutin, luteolin-7-glucoside, nüzhenide, oleuropein, and ligstroside were the main phenolic compounds identified in the extracts. ‘Galega’ was the most promising cultivar due to its high concentration of phenolic compounds, high antioxidant capacity, and remarkable inhibition of AChE, BChE, and TYR. It can be concluded that olive seed extracts may provide a sustainable source of bioactive compounds for medical and industrial applications.

Toxicity evaluation of traditional and organic yerba mate (Ilex paraguariensis A. St.-Hil.) extracts

Yerba mate (Ilex paraguariensis A. St.-Hil.) is an important source of biologically active compounds with pharmacological potential. The aim of this study was to examine the toxicity of different extracts obtained from either traditional or organic cultivated yerba mate in vitro and in vivo. Aqueous, ethanolic and methanolic extracts were obtained from commercial samples of yerba mate and total phenolic content was determined employing Folin-Ciocalteau reagent. The aqueous extracts presented higher content of total phenols, compared to ethanolic and methanolic extracts, and also demonstrated lower cytotoxicity, which is the basis for testing were carried out only using aqueous extracts. The main phenolic acids found in traditional aqueous (TA) extract were chlorogenic, gallic and protocatechuic acids. Gallic and hydroxybenzoic acids were detected in aqueous cultivated organic (OA) extract. Pretreatment with OA extract (100 µg/ml, 1 hr) was cytoprotective against rotenone-induced toxicity (1 µM). For in vivo toxicity assay, zebrafish embryos were exposed to OA or TA extracts (10-160 µg/ml) at 4 hr post fertilization. TA extract decreased embryos survival in a concentration-dependent manner, reduced the hatching rate at 40 µg/ml, increased edema frequency at 80 µg/ml and altered body curvature at 120 µg/ml. Further, TA extract produced locomotor disorders at concentrations equal to or greater than 10 µg/ml. In contrast, OA extract exhibited no apparent toxic effect on organogenesis and behavior up to 100 µg/ml. In summary, the OA cultivated extract showed the lowest cytotoxicity in vitro, enhanced reduction in rotenone-induced toxicity, and produced less toxicity in zebrafish embryos compared to the TA extract.

Molecular Structure-Based Screening of the Constituents of Calotropis procera Identifies Potential Inhibitors of Diabetes Mellitus Target Alpha Glucosidase

Diabetes mellitus is a disorder characterized by higher levels of blood glucose due to impaired insulin mechanisms. Alpha glucosidase is a critical drug target implicated in the mechanisms of diabetes mellitus and its inhibition controls hyperglycemia. Since the existing standard synthetic drugs have therapeutic limitations, it is imperative to identify new potent inhibitors of natural product origin which may slow carbohydrate digestion and absorption via alpha glucosidase. Since plant extracts from Calotropis procera have been extensively used in the treatment of diabetes mellitus, the present study used molecular docking and dynamics simulation techniques to screen its constituents against the receptor alpha glucosidase. Taraxasterol, syriogenin, isorhamnetin-3-O-robinobioside and calotoxin were identified as potential novel lead compounds with plausible binding energies of −40.2, −35.1, −34.3 and −34.3 kJ/mol against alpha glucosidase, respectively. The residues Trp⁴⁸¹, Asp⁵¹⁸, Leu⁶⁷⁷, Leu⁶⁷⁸ and Leu⁶⁸⁰ were identified as critical for binding and the compounds were predicted as alpha glucosidase inhibitors. Structurally similar compounds with Tanimoto coefficients greater than 0.7 were reported experimentally to be inhibitors of alpha glucosidase or antidiabetic. The structures of the molecules may serve as templates for the design of novel inhibitors and warrant in vitro assaying to corroborate their antidiabetic potential.

Purple tea (Camellia sinensis var. assamica) leaves as a potential functional ingredient: From extraction of phenolic compounds to cell-based antioxidant/biological activities

A statistical optimization study was used to maximize the extraction of bioactive compounds and antioxidant activity from green tea derived from purple leaves of Camellia sinensis var. assamica. Simultaneous optimization was applied, and a combination of 60 °C, 15 min, and a mass-solvent ratio of 1 g of dehydrated purple leaves to 62.3 mL of an ethanol/citric acid solution, were determined as the ideal extraction conditions. The optimized extract of purple tea leaves (OEPL) contained showed stability in relation to variations in pH, and lyophilized OEPL exerted cytotoxic and antiproliferative effects against cancerous cells (A549 and HCT8), demonstrated antimicrobial activity towards Listeria monocytogenes (ATCC 7644), Staphylococcus aureus (ATCC 13565) and Staphylococcus epidermidis (ATCC 12288), inhibition of α-amylase and α-glycosidase enzymes and reduced the release of pro-inflammatory cytokines (TNF-α, CXCL2/MIP-2, and IL-6) in lipopolysaccharides-stimulated RAW 264.7 macrophages. Thus, our results provide a broad assessment of the bioactivity of "green" extracts obtained by a simple and low-cost process using non-toxic solvents, and they have the potential to be used for technological applications.

Dynamic changes of phenolic acids and antioxidant activity of Citri Reticulatae Pericarpium during aging processes

Citri reticulatae pericarpium (CRP) shows multiple bioactivities, including antioxidant, anti-tumor, and anti-inflammation. The folk proverb "CRP, the older, the better" means storing for longer time would improve its quality, which attributed to the influence of bioactive compounds. The aim of this work was to study which compounds are the factors that long storage would influence the quality of CRP. 161 compounds, including 65 flavonoids, 51 phenolic acids, 27 fatty acids, and 18 amino acids were identified through derivatization and non-derivatization liquid chromatography mass spectrometry approaches. Their dynamic changes indicated phenolic acids, which were reported to have various activities, were the main increased components. Furthermore, the representative phenolic acids were quantified and correlation analysis between their contents and antioxidant activity implicated they were the possible indicators that long storage would improve CRP quality. The results would provide basis for quality control of CRP during storage.

Technological applications of phenolic-rich extracts for the development of non-dairy foods and beverages

Fruits and other vegetables are sources of bioactive compounds, especially carotenoids, terpenoids, and phenolic compounds. With the focus on sustainability, these compounds' recovery has become a research trend in the last 20 years. However, the correct use of solvents and the steps required to assess the extracts' suitability to be added in food models have been poorly described. Thus, in this review, we attempt to show the pathways and provide guidance on the tailored-made use of solvents for recovering bioactive polyphenolic compounds from food matrices. Special attention is given to the toxicological safety of polyphenol-rich extracts and also their impacts on bioactivity and sensory acceptance of foods and beverages. Practical examples are described and commented on the applications of polyphenol-rich extracts in non-dairy foods and beverages. In summary, the alliance among food science, food technologies, biochemistry, and pharmacology are required to make the development of non-dairy polyphenol-rich foods feasible.

Preharvest Nutrient Deprivation Reconfigures Nitrate, Mineral, and Phytochemical Content of Microgreens

While imparting gastronomic novelty and sensory delight, microgreens also constitute rudimentary leafy greens packed with nutrients and phytochemicals. As such, they comprise an upcoming class of functional foods. However, apart from bioactive secondary metabolites, microgreens also accumulate antinutritive agents such as nitrate, especially under conducive protected cultivation conditions. The current work examined nutrient deprivation before harvest (DBH), applied by replacing nutrient solution with osmotic water for six and twelve days, as a strategy for reducing microgreen nitrate levels in different species (lettuce, mustard, and rocket). The three species were sown on a peat-based substrate, cultivated in a controlled climate chamber, and harvested 18 days after sowing, when the first two true leaves emerged. DBH impact on major constituents of the secondary metabolome, mineral content, colorimetric, and yield traits was appraised. Nitrate and mineral content were determined through ion chromatography, phenolic composition through UHPLC-Q-Orbitrap HRMS, and carotenoid composition through HPLC-DAD. Nutrient deprivation was effective in reducing nitrate content; however, effective treatment duration differed between species and decline was more precipitous in nitrate hyperaccumulating species such as rocket. Quercetin and kaempferol glycosides were the flavonol glycosides most abundant in brassicaceous microgreens, whereas lettuce microgreens were steeped in caffeoyl quinic acid. DBH interacted with species as it increased the total phenolic content of lettuce, decreased that of rocket, but did not affect mustard. Further research to link changes in phenolic composition to the sensory and in vivo bioactive profile of microgreens is warranted. Notably, brief (≤6 days) DBH can be applied across species with moderate or no impact on the phenolic, carotenoid, and mineral composition of microgreens. Brief DBH applications also have limited impact on microgreens' yield and colorimetric traits hence on the commercial value of the product. They can therefore be applied for reducing microgreen nitrate levels without significantly impacting key secondary metabolic constituents and their potential bioactive role.

Effect-Directed Profiling of 17 Different Fortified Plant Extracts by High-Performance Thin-Layer Chromatography Combined with Six Planar Assays and High-Resolution Mass Spectrometry

An effect-directed profiling method was developed to investigate 17 different fortified plant extracts for potential benefits. Six planar effect-directed assays were piezoelectrically sprayed on the samples separated side-by-side by high-performance thin-layer chromatography. Multipotent compounds with antibacterial, α-glucosidase, β-glucosidase, AChE, tyrosinase and/or β-glucuronidase-inhibiting effects were detected in most fortified plant extracts. A comparatively high level of antimicrobial activity was observed for Eleutherococcus, hops, grape pomace, passiflora, rosemary and Eschscholzia. Except in red vine, black radish and horse tail, strong enzyme inhibiting compounds were also detected. Most plants with anti-α-glucosidase activity also inhibited β-glucosidase. Green tea, lemon balm and rosemary were identified as multipotent plants. Their multipotent compound zones were characterized by high-resolution mass spectrometry to be catechins, rosmarinic acid, chlorogenic acid and gallic acid. The results pointed to antibacterial and enzymatic effects that were not yet known for plants such as Eleutherococcus and for compounds such as cynaratriol and caffeine. The nontarget effect-directed profiling with multi-imaging is of high benefit for routine inspections, as it provides comprehensive information on the quality and safety of the plant extracts with respect to the global production chain. In this study, it not only confirmed what was expected, but also identified multipotent plants and compounds, and revealed new bioactivity effects.

Bioactive compounds, antioxidant capacity and antitumoral activity of ethanolic extracts from fruits and seeds of Eugenia involucrata DC

Eugenia involucrata DC. (Myrtaceae) is a native tree species from Brazil that has been scarcely studied. We investigated the phenolic composition, the antioxidant capacity and the antitumoral activity of ethanolic extracts from fruits (FE) and seeds (SE) of E. involucrata. Six anthocyanins were identified by UPLC-PDA/MS/MS in FE, being four derived from cyanidin, and the other ones derived from delphinidin and pelargonidin. Using HPLC-PDA, FE presented a larger number of phenolic compounds (epicatechin, catechin, rutin, ellagic acid, myricetin and quercetin) than SE, which did not show myricetin and quercetin. However, SE showed higher total phenolic content and generally stronger in vitro antioxidant capacity than FE, except that only FE exhibited superoxide radical scavenging activity, which may be attributed to the anthocyanins present in fruits. Additionally, only SE exhibited antitumoral activity in a pancreatic cancer cell line (PANC-1). The antitumoral mechanisms involved imbalance of antioxidant status, alteration of mitochondrial membrane potential, cytoskeleton disassembly and induction of cell death by apoptosis and necrosis. Compared to the standard antitumoral drug gemcitabine, SE exhibited higher antitumoral efficacy and selectivity index. The highest concentration of total phenolics and of specific phenolic compounds bearing antitumoral properties may be related to the antitumoral activity of SE. Our results corroborate previous data of E. involucrata as an important source of bioactive compounds and provide, for the first time, evidences of in vitro antitumoral potential of its seeds on pancreatic cancer cell line.

Increased stability and intracellular antioxidant activity of chlorogenic acid depend on its molecular interaction with wheat gluten hydrolysate

Gastrointestinal stability and cell entry efficiency affect the biological accessibility of chlorogenic acid (CGA). Here, wheat gluten hydrolysate (WGH) was proven to improve the stability of CGA during simulated gastrointestinal digestion, promote the intestinal epithelial cell entry efficiency of CGA, and increase its intracellular antioxidant activity. The interaction between WGH and CGA was studied by fluorescence quenching and molecular dynamics simulations. The thermodynamic parameters and molecular dynamics simulation analysis showed that the interaction between WGH and CGA was dependent on hydrogen bonding and hydrophobic and electrostatic interactions. Analyses of the binding sites of WGH showed that Arg12, Arg49, Lys54, and Pro74-Gln89 had strong interactions with CGA molecules. This interaction between CGA and WGH was related to both electrostatic interactions and their respective concentrations. Taken together, the stability, intestinal epithelial cell entry, and antioxidant activity of CGA can be increased by its molecular interactions with WGH.

Phenolic Constitution, Phytochemical and Macronutrient Content in Three Species of Microgreens as Modulated by Natural Fiber and Synthetic Substrates

The present study examined the modulatory effects of natural fiber substrates (agave fiber, coconut fiber and peat moss) and synthetic alternatives (capillary mat and cellulose sponge) on the nutritive and phytochemical composition of select microgreens species (coriander, kohlrabi and pak choi) grown in a controlled environment. Polyphenols were analyzed by UHPLC-Q-Orbitrap-HRMS, major carotenoids by HPLC-DAD, and macro-minerals by ion chromatography. Microgreens grown on peat moss had outstanding fresh and dry yield but low dry matter content. Natural fiber substrates increased nitrate and overall macro-mineral concentrations in microgreens compared to synthetic substrates. The concentrations of chlorophylls, carotenoids and ascorbate were influenced primarily by species. On the contrary, variability in polyphenols content was wider between substrates than species. Out of twenty phenolic compounds identified, chlorogenic acid and quercetin-3-O-rutinoside were most abundant. Hydroxycinnamic acids and their derivatives accounted for 49.8% of mean phenolic content across species, flavonol glycosides for 48.4% and flavone glycosides for 1.8%. Peat moss provided optimal physicochemical conditions that enhanced microgreens growth rate and biomass production at the expense of phenolic content. In this respect, the application of controlled stress (eustress) on microgreens growing on peat moss warrants investigation as a means of enhancing phytochemical composition without substantial compromise in crop performance and production turnover. Finally, nitrate deprivation practices should be considered for microgreens grown on natural fiber substrates in order to minimize consumer exposure to nitrate.