Phenolic Secondary Metabolites Research Articles

Calafate (Berberis microphylla G. Forst) Populations from Chilean Patagonia Exhibit Similar Structuring at the Genetic and Metabolic Levels

Berberis microphylla, commonly known as calafate, is one of the most promising species of Chilean Patagonia to be domesticated, due to its anthocyanin-rich berries. The main aim of this study was to understand the genetic structure of the wild populations of B. microphylla in the main regions where it grows and its relationship with phenolic secondary metabolite profiles. Ripe berry samples and leaves were collected from the Aysén and Magallanes regions. Genetic analyses were carried out using 18 microsatellite markers. Phenolic compounds were extracted from the ripe fruits and were quantified using high-performance liquid chromatography (HPLC). Their antioxidant capacity was determined according to the Trolox equivalent antioxidant capacity (TEAC) assay. Total phenols were measured as their absorbance at a wavelength of 280 nm. Both the genetic and chemometric data were explored using unsupervised and supervised methods. The genetic markers suggest the existence of three groups, two of them corresponding to the Aysén and Magallanes samples, and the third corresponding to Chile Chico (a district in Aysén), which was the most divergent of the three. Similar results were observed in the phenolic profile obtained with chemometric analysis, with the same samples forming a separate third group. The differentiation achieved using the genetic and chemical data may be the result of intrinsic genetic differences, environmental effects on fruit maturity, or the sum of both factors. These are all points to consider in the domestication of this valuable species by selecting individuals with desirable traits and contrasting phenotypes.

Correlation analysis of secondary metabolites and disease resistance activity of different varieties of Congou black tea based on LC-MS/MS and TCMSP

To investigate the correlation between the difference of secondary metabolites and the disease-resistance activity of different varieties of Congou black tea. Among a total of 657 secondary metabolites identified, 183 metabolites had anti-disease activity, 113 were key active ingredients in traditional Chinese medicine (TCM), 73.22% had multiple anti-disease activities, and all were mainly flavonoids and phenolic acids. The main enriched metabolic pathways were phenylpropanoid biosynthesis, biosynthesis of secondary metabolites, flavonoid biosynthesis, and metabolic pathways. Flavonoid and phenolic acid secondary metabolites were more correlated with anti-disease activity and key active TCM ingredients. Conclusion: The types of JGY and Q601 Congou black tea of the relative contents show large differences in secondary metabolites. Flavonoid and phenolic acid secondary metabolites were identified as the primary factors contributing to the variation in secondary metabolites among different varieties of Congou black tea. These compounds also exhibited a stronger correlation with disease resistance activity.

Phytochemical Profile, Antioxidant and Cytotoxic Potential of Capsicum annuum (L.) Dry Hydro-Ethanolic Extract.

Capsicum annuum (L.) is one of the essential spices most frequently used in our daily routine and has remarkable ethnobotanical and pharmacological properties. Its fruits are rich in vitamins, minerals, carotenoids, and numerous other phenolic metabolites with a well-known antioxidant activity. Regular consumption of chili fruits may have a positive influence on human health. Therefore, we investigated a commercially available chili fruit powder in the present study, extracting it with 50% ethanol. The dried hydro-ethanolic extract (CAE) was thoroughly analyzed using ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS/MS), and 79 bioactive phenolic constituents were identified. Then, we quantified the main phenolic compounds and found a polyphenol content of 4.725 ± 1.361 mg Eq tannic acid/100 g extract and a flavonoid amount of 1.154 ± 0.044 mg Eq rutin/100 g extract. Phenolic secondary metabolites are known for their dual redox behavior as antioxidants/pro-oxidants, underlying their numerous benefits in health and disease. Thus, the antioxidant potential of CAE was evaluated using three methods; our results could explain the protective effects of chili fruits: IC50DPPH = 1.669 mg/mL, IC50ABTS = 0.200 mg/mL, and EC50FRAP = 0.561 mg/mL. The pro-oxidant potential of phenolic compounds could be a basis for CAE cytotoxicity, investigated in vitro on tumor cell lines and in vivo on Daphnia sp. Results demonstrated the dose- and time-dependent CAE's cytotoxic activity; the highest antiproliferative activity was recorded on colon (LoVo) and breast (MDA-MB-231) cancer cell lines after 48 h of exposure (IC50 values < 200 µg/mL). In vivo testing on Daphnia sp. reported a potent CAE cytotoxicity after 48 h and embryonic developmental delays. Extensive data analyses support our results, showing a significant correlation between the CAE's concentration, phenolic compound content, antioxidant activity, exposure time, and the viability rate of different tested cell lines.

Natural- and in vitro-grown Filipendula ulmaria (L.) Maxim: evaluation of pharmaceutical potential (antibacterial, antioxidant and toxicity) and phenolic profiles

Meadowsweet (Filipendula ulmaria (L.) Maxim) is Rosaceae family perennial herb. Traditional uses of F. ulmaria include inflammatory problems like rheumatism, arthrosis, and arthritis), gastrointestinal disorders, liver malfunction, and gout. The pharmaceutical industry has been very interested in this plant because of its health benefits. The presence of phenolic secondary metabolites is thought to be the primary cause of meadowsweet's biological activity and therapeutic efficacy. This study was intended to compare and evaluate the biological activities (antibacterial, antioxidant, antitumor and toxicity) and phenolic profiles (total phenol-flavonoid content and individual phenolic constituents) of F. ulmaria aerial parts obtained from two different sources (naturally- and in vitro-grown). Antibacterial activity was evaluated using 17 different bacteria (10 human and 7 fish pathogens) with disc diffusion method. Methanolic extracts of in vitro-grown parts showed higher antibacterial effect than naturally-grown parts with all tested bacterial pathogens (human and fish). On the other hand, other extracts (aqueous, ethanol, hexane, and ethyl acetate) demonstrated higher antibacterial potential with field-grown parts. The highest sensitivity was observed with Staphylococcus epidermidis, S. aureus and Enterobacter cloacae to aqueous extract of field-grown plants. The potent antibacterial activity of F. ulmaria extracts rendered the Agrobacterium tumefaciens-induced potato disc tumor assay inapplicable. Toxicity assay (brine shrimp) showed that aqueous extract of both sources had the lowest toxicity. Methanolic extract of both parts had a strong antioxidant potential (DPPH radical scavenging activty) having IC50 values as 205.65 µg/mL and 206.74 µg/mL, respectively, and similar level of overall total phenol-flavonoid contents. Individual phenolic analysis with HPLC-DAD showed that the most prevalent phenol was rutin in both sources. While the quantities of chlorogenic acid in both aerial parts were similar, the parts that were grown naturally had higher levels of salicylic acid and rutin. These findings demonstrated the effective antibacterial and antioxidant properties, high phenolic content, and low toxicity of both F. ulmaria sources, indicating that they can be utilized in nutraceutical industry due to their high health promoting potential.

The Effect of External Treatment of Arabidopsis thaliana with Plant-Derived Stilbene Compounds on Plant Resistance to Abiotic Stresses.

Stilbenes are a group of plant phenolic secondary metabolites, with trans-resveratrol (3,5,4'-trihydroxy-trans-stilbene) being recognized as the most prominent and studied member. Stilbenes have a great potential for use in agriculture and medicine, as they have significant activities against plant pathogens and have valuable beneficial effects on human health. In this study, we analyzed the effects of direct application of stilbenes, stilbene precursor, and stilbene-rich extract solutions to the plant foliar surface for increasing the resistance of Arabidopsis thaliana to various abiotic stresses (heat, cold, drought, and soil salinity). Exogenous treatment of A. thaliana with stilbenes (trans-resveratrol, piceid, and spruce bark extract) and phenolic precursor (p-coumaric acid or CA) during germination resulted in considerable growth retardation of A. thaliana plants: a strong delay in the root and stem length of 1-week-old seedlings (in 1.3-4.5 fold) and rosette diameter of 1-month-old plants (in 1.2-1.8 fold), while the 2-month-old treated plants were not significantly different in size from the control. Plant treatments with stilbenes and CA increased the resistance of A. thaliana to heat and, to a lesser extent, to soil salinity (only t-resveratrol and spruce extract) to drought (only CA), while cold resistance was not affected. Plant treatments with stilbenes and CA resulted in a significant increase in plant resistance and survival rates under heat, with plants showing 1.5-2.3 times higher survival rates compared to untreated plants. Thus, exogenous stilbenes and a CA are able to improve plant survival under certain abiotic stresses via specific activation of the genes involved in the biosynthesis of auxins, gibberellins, abscisic acid, and some stress-related genes. The present work provides new insights into the application of stilbenes to improve plant stress tolerance.

Phytochemical Screening, Identification of Compounds, and Antioxidant Activity Test of Sirsak Extract (Annona muricata, L.) Leaf Grown in North Sumatra, Indonesia

The research is to identify and analyze the secondary metabolite content of sirsak (Annona muricata, L.) leaves, which are extracted with ethanol and water solvents, and determine their potential activity as antioxidants. Extraction using ethanol (Merck) and water as solvent; phytochemical screening uses standard reagents: FeCl3 5% in water, FeCl3 1%, Dragendrof, Mayer, Wagner, Mg ribbon, HCl (concentrated), Liberman-Buchard. Analysis of secondary metabolite compound components from the extract using GC-MS Shimadzu (QP-2010S Shimadzu, Japan) and determination of potential antioxidant activity using the DPPH method. Phytochemical screening of the ethanol extract of A. muricata leaf contains phenolic secondary metabolites, flavonoids, saponins, tannins, alkaloids, and triterpenoids. According to phytochemical screening, A. muricata leaf water extract contains phenolic compounds, tannins, flavonoids, alkaloids, and steroids. The results of ethanol extract analysis using GC-MS obtained 24 types of secondary metabolite compounds with the three highest secondary metabolite compounds, namely dodecanoic acid, 1,2,3-propanetriyl ester (16.76%), dodecanoic acid, 1,2,3-propanetriyl esters (16.52%), and glycerol trilaurate (15.07%); A. muricata leaf water extract contains 15 metabolite compound components with the three highest secondary metabolite compounds, namely n-hexadecoic acid (37.40%), 9-Hexadecenoic acid (16.59%), and benzeneethanol, 4-hydroxy (6.76%). The antioxidant activity value extracted with water solvent has an IC50 of 99.96 ppm, and that extracted with ethanol has an IC50 of 264.51 ppm. A. muricata extract leaf contains various secondary metabolites, and samples extracted with water show better antioxidant activity compared to samples extracted with ethanol.

Quality Breeding in Leafy Vegetables

Vegetables are commonly known as "protective foods" in the human diet owing to their quantity of vitamins, essential fatty acids, minerals, amino acids, and dietary fiber, as well as a range of critical bioactive compounds. These include health-promoting phenolic chemicals and secondary plant metabolites that are high in antioxidants. Greens are the best and most economical sources of protein. This is because of their ability to use the abundant amounts of nitrogen, sunlight, water, and oxygen in the environment to synthesize and accumulate amino acids. It has long been recognized that green leafy vegetables are a great source of dietary fiber. The WHO states that in order to effectively combat general malnutrition, it is now necessary to consider the micronutrient status of the diet. Breeding green vegetables with high nutritional content can help solve this problem.

Analysis of Softwood Lignans by Comprehensive Two-Dimensional Liquid Chromatography.

Lignans constitute a large group of phenolic plant secondary metabolites possessing high bioactivity. Their accurate determination in plant extracts with a complex chemical composition is challenging and requires advanced separation techniques. In the present study, a new approach to the determination of lignans in coniferous knotwood extracts as the promising industrial-scale source of such compounds based on comprehensive two-dimensional liquid chromatography separation and UV spectrophotometric detection is proposed. First and second-dimension column screening showed that the best results can be obtained using a combination of non-polar and polar hydroxy group embedded octadecyl stationary phases with moderate (~40%) "orthogonality". The optimization of LC × LC separation conditions allowed for the development of a new method for the quantification of the five lignans (secoisolariciresinol, matairesinol, pinoresinol, 7-hydroxymatairesinol, and nortrachelogenin) in knotwood extracts with limits of quantification in the range of 0.27-0.95 mg L-1 and a linear concentration range covering at least two orders of magnitude. Testing the developed method on coniferous (larch, fir, spruce, and pine) knotwood extracts demonstrated the high selectivity of the analysis and the advantages of LC × LC in the separation and accurate quantification of the compounds co-eluting in one-dimensional HPLC.

A Perusal of Phenolics Within Polar Peel Fractions of Malus domestica var Maharaji via Hyphenated Techniques Cum Anti-microbial with REMA and Tyrosinase Inhibitory Potential thereof

This study aims to scrutinize the phenolic secondary metabolites in the polar peel decocture of Malus domestica var Maharaji via hyphenated techniques along with the study of the antibacterial, anti-candida, and tyrosinase inhibitory potential of bioactive compound-rich fractions. Preliminary phenolics go over was performed together with thin layer chromatography before the polar decocture was subjected to hyphenated techniques. FTIR investigation revealed the C-O bonds as in phenols, O-H bond stretch, and vibrations of alcohols and carboxylic acids as well as portrayed the C-H and &gt;C=O stretches among other functional groups all of which are representative of phenolic and polyphenolic compounds. GC-MS perusal demonstrated the presence of bioactive compounds like Quercetin (13.04%), Ascorbic acid (6.48%), p-Coumaric acid (6.17%), Caffeic acid (5.69 %), Mallic acid (5.44%), Apigenin (5.28%), Citric acid (5.15%), Gallic acid (4.38%), Cyanidin (3.52%), and Ferulic acid (3.51%). Kirby-Bauer method followed by the resazurin microtiter assay technique (REMA) for MIC/MBC against six MTCC bacterial strains and one yeast, all producing stubborn opportunistic infection in humans, was used to assess the antibacterial property of all the bioactive rich fractions. Some fractions comparatively revealed a good activity index (AI) against tested microbes. MIC concentrations for bacteria ranged from 15-24 mg/ml while a lower MBC value recorded was 18 mg/ml. Methanol fraction revealed significant tyrosinase inhibitory activity by revealing IC50 of 980.98 µg/ml when L-Tyrosine was substrate and IC50 of 830.68 µg/ml when L-DOPA was substrate when juxtaposed to standard kojic acid that revealed IC50 of 128.822 µg/ml when L-Tyrosine was substrate and IC50 of 149.43 µg/ml when L-DOPA was substrate. The bioactive compounds possessed by the fractions, may be synergistically, turned out to be more effective in the diphenolase reaction and kojic acid acts more effectively in the monophenolase one. It was inferred that peel phenolics of this malus variety have a lot of therapeutic potential in the context of bacterial infections and pigmentation disorders.

Profile and potential bioactivity of the miRNome and metabolome expressed in Malva sylvestris L. leaf and flower

Malva sylvestris L. (common mallow) is a plant species widely used in phytotherapy and ethnobotanical practices since time immemorial. Characterizing the components of this herb might promote a better comprehension of its biological effects on the human body but also favour the identification of the molecular processes that occur in the plant tissues. Thus, in the present contribution, the scientific knowledge about the metabolomic profile of the common mallow was expanded. In particular, the phytocomplex of leaves and flowers from this botanical species and the extraction capacity of different concentrations of ethanol (i.e., 95%, 70%, 50%, and 0%; v/v in ddH2O) for it were investigated by spectrophotometric and chromatographic approaches. In detail, 95% ethanol extracts showed the worst capacity in isolating total phenols and flavonoids, while all the hydroalcoholic samples revealed a specific ability in purifying the anthocyanins. HPLC–DAD system detected and quantified 20 phenolic secondary metabolites, whose concentration in the several extracts depended on their own chemical nature and the percentage of ethanol used in the preparation. In addition, the stability of the purified phytochemicals after resuspension in pure ddH2O was also proved, considering a potential employment of them in biological/medical studies which include in vitro and in vivo experiments on mammalian models. Here, for the first time, the expressed miRNome in M. sylvestris was also defined by Next Generation Sequencing, revealing the presence of 33 microRNAs (miRNAs), 10 typical for leaves and 2 for flowers. Then, both plant and human putative mRNA targets for the detected miRNAs were predicted by bioinformatics analyses, with the aim to clarify the possible role of these small nucleic acids in the common mallow plant tissues and to try to understand if they could exert a potential cross-kingdom regulatory activity on the human health. Surprisingly, our investigations revealed that 19 miRNAs out of 33 were putatively able to modulate, in the plant cells, the expression of various chromosome scaffold proteins. In parallel, we found, in the human transcriptome, a total of 383 mRNAs involved in 5 fundamental mammalian cellular processes (i.e., apoptosis, senescence, cell-cycle, oxidative stress, and invasiveness) that theoretically could be bound and regulated by M. sylvestris miRNAs. The evidence collected in this work would suggest that the beneficial properties of the use of M. sylvestris, documented by the folk medicine, are probably linked to their content of miRNAs and not only to the action of phytochemicals (e.g., anthocyanins). This would open new perspectives about the possibility to develop gene therapies based on miRNAs isolated from medicinal plants, including M. sylvestris.

Inter- and intraspecific diversity of Salix bark phenolic profiles – A resource for the pharmaceutical industry

Due to their content of phenolic compounds, willow bark preparations are used as an herbal remedy. The large diversity of phenolic secondary metabolites in Salix still provides a resource for the identification of bioactive compounds in particular species, including species not yet in focus from a phytopharmaceutical perspective. The present study describes the bark phenolic profile of 13 Salix species analyzed by HPLC-MS: Salix alba, Salix babylonica, Salix daphnoides, Salix fragilis, Salix hastata, Salix myrsinifolia, Salix pentandra, Salix purpurea, Salix repens (including subspecies S. repens ssp. arenaria and S. repens ssp. repens), Salix rosmarinifolia, Salix sachalinensis, Salix triandra and Salix viminalis. The analyzed profiles comprised the chemical groups of salicylates, flavonoids, procyanidins, phenolic acid derivatives, and some unclassified phenolics. Particular compounds were detected in species where they have not been previously reported. Apart from interspecific diversity, qualitative variability within species was observed as certain components were detected only in some of the analyzed genotypes. The knowledge on specific phenolic profiles of species and genotypes is the basis for the selection of suitable willow bark material with certain desired bioactive properties. Furthermore, the high inter- and intraspecific variability points out the necessity for product standardization of willow bark raw material.

Influence of the content of biologically active phenolic compounds in the fruits of Malus Mill. on their quality indicators

The article presents the results of an analytical review of Russian and foreign literature sources devoted to the study of the influence of the composition and functions of phenolic compounds in apple fruits on their quality indicators (appearance, pulp density, nutritional value). Studies of the biochemical composition of apple fruits are currently relevant and are being carried out with the aim of in-depth study of the assortment of fruit crops and assessment of its potential use in breeding to increase the content of biologically active compounds. The prospects of the search for plants that accumulate phenolic compounds in tissues, which have a protective antioxidant function and nutritional value, have been confirmed. The issue of the role of accumulation, the dynamics of the content of individual phenolic compounds and the total content of phenolic compounds in various metabolic processes that determine the properties of apple fruits is considered. Analysis of the results of thematic scientific works on changes in the composition and content of phenolic compounds will allow targeted research leading to the use of fruits as a potential source of phenolic compounds, as well as identifying sources of accumulation of biologically active substances for practical use in breeding. The creation of new varieties of apple trees is necessary to obtain useful secondary phenolic metabolites contained in fruits, while the range of use of fruits includes the production of processed products. The expediency of carrying out breeding work aimed at increasing the content of phenolic compounds in fruits is confirmed by a number of recent publications by Russian and foreign scientists.

Screening in silico the human epidermal growth factor receptor-2inhibitory effect of isoflavones by molecular docking method for their potential use in breast cancer

Isoflavones are secondary phenolic metabolites found in most legumes. These compounds have important pharmacological significance such as anti-osteoporosis, anti-aging, and anti-cancer properties. Breast cancer is one of the most common cancers in women worldwide. Human epidermal growth factor receptor-2 (HER2) is an important target in breast cancer treatment. In this study, we evaluated the ability of sixty isoflavones compounds to inhibit the HER2 enzyme for their potential use in breast cancer treatments by the molecular docking method. Molecular docking was done by Autodock vina software. Lipinski 5 rule is used to compare compounds with drug-like and non-drug-like properties. Pharmacokinetic parameters of potential compounds were evaluated using the pkCSM tool. Our results showed that 35 compounds inhibited HER2 stronger than the positive control. Next, we analysed the drug-likeness according to Lipinski’s rule of five and predicted pharmacokinetic-toxicological parameters of these 35 compounds. We obtained two compounds, genistein and biochanin A, which could become promising drugs for breast cancer treatment. However, in vitro and in vivo studies on the inhibition of the HER2 enzyme need to be conducted.

Volatile Oil Yield and Composition, Total Phenolic Content, Antioxidant Activity and Secondary Metabolite Content of Collected Thymus praecox Species in Rize.

In this study, the volatile oil yield (Clevenger), volatile oil (VO) composition (Gas Chromatography), phenolic contents (UV-VIS Spectrophotometer), antioxidant activities (UV-VIS Spectrophotometer) and secondary metabolite content (High Pressure Liquid Chromatography) of 11 Thymus praecox subspecies were evaluated. The most detected chemical class were oxygenated monoterpenes (55.18-86.1 %) in investigated samples. In the present study rosmarinic acid, isoquercitrin, gallocatechin and thymol could be detected in high amounts. The min. and max. content values of Flora/Field Samples were 1543.241 and 890.3-1425.3 for rosmarinic acid, 139.44-287.894 and 129.9-312.2 for thymol, 38.619-121.424 and 26.3-112.9 for gallocatechin as mg/g DW. Principal Component Analysis was used to differentiate Thymus praecox species regarding volatile oil composition and secondary metabolite content. The results demonstrated that T. praecox collected from the Rize flora and cultivated afterwards showed variability based on investigated characteristics. Finally, the Thymus praecox samples displaying high bioactive compounds present useful information for further investigations and applications.

Extraction of Gallic Acid and Ferulic Acid for Application in Hair Supplements

Food supplements based on antioxidants and vitamins are often prescribed to correct inefficiencies in the human diet and delay diseases such as premature aging and alopecia (temporary or permanent hair loss), given the free radical scavenging activity of these biomolecules. By reducing the concentration of reactive oxygen species (ROS), which promote abnormal hair follicle cycling and morphology, follicle inflammation and oxidative stress are reduced, minimising the effects of these health issues. Gallic acid (GA), which is significantly present in gallnuts and in pomegranate root bark, and ferulic acid (FA), commonly found in brown rice and coffee seeds, are very important antioxidants for the preservation of hair colour, strength and growth. In this work, these two secondary phenolic metabolites were successfully extracted in the Aqueous Two-Phase Systems (ATPS) {ethyl lactate (1) + trisodium citrate (2) + water (3)} and {ethyl lactate (1) + tripotassium citrate (2) + water (3)} at 298.15 K and 0.1 MPa, moving towards the application of these ternary systems in extracting antioxidants from biowaste and their a posteriori processing as food supplements for hair fortification. The studied ATPS provided biocompatible and sustainable media for the extraction of gallic acid and ferulic acid, yielding low mass losses (<3%) and contributing to an eco-friendlier production of therapeutics. The most promising results were obtained for ferulic acid, which attained maximum partition coefficients (K) of 15 ± 5 and (3 ± 2) · 101 and maximum extraction efficiencies (E) of (92.7 ± 0.4)% and (96.7 ± 0.4)% for the longest tie-lines (TLL = 69.68 and 77.66 m%) in {ethyl lactate (1) + trisodium citrate (2) + water (3)} and {ethyl lactate (1) + tripotassium citrate (2) + water (3)}, respectively. Moreover, the effect of pH on the UV-Vis absorbance spectra was studied for all the biomolecules to minimise errors in solute quantification. Both GA and FA were found to be stable at the used extractive conditions.

Inhibitory effects of flavonoids on glucose transporter 1 (GLUT1): From library screening to biological evaluation to structure-activity relationship

Glucose transporter 1 (GLUT1) is mainly responsible for glucose uptake and energy metabolism, especially in the aerobic glycolysis process of tumor cells, which is closely associated with the advancement of tumors. Numerous studies have demonstrated that the inhibition of GLUT1 can decrease the growth of tumor cells and enhance drug sensitivity, so GLUT1 is considered to be a promising therapeutic target for cancer treatment. Flavonoids are a group of phenolic secondary metabolites present in vegetables, fruits, and herbal products, some of which were reported to increase cancer cells' sensitivity to sorafenib by inhibiting GLUT1. Our objective was to screen potential inhibitors of GLUT1 from 98 flavonoids and assess the sensitizing effect of sorafenib on cancer cells. and illuminate the structure–activity relationships of flavonoids with GLUT1. Eight flavonoids, including apigenin, kaempferol, eupatilin, luteolin, hispidulin, isosinensetin, sinensetin, and nobiletin exhibited significant inhibition (>50%) on GLUT1 in GLUT1-HEK293T cells. Among them, sinensetin and nobiletin showed stronger sensitizing effects and caused a sharp downward shift of the cell viability curves in HepG2 cells, illustrating these two flavonoids might become sensitizers to enhance the efficacy of sorafenib by inhibiting GLUT1. Molecular docking analysis elucidated inhibitory effect of flavonoids on GLUT1 was related to conventional hydrogen bonds, but not Pi interactions. The pharmacophore model clarified the critical pharmacophores of flavonoids inhibitors are hydrophobic groups in 3’positions and hydrogen bond acceptors. Thus, our findings would provide useful information for optimizing flavonoid structure to design novel GLUT1 inhibitors and overcome drug resistance in cancer treatment.

Thymus Species from Romanian Spontaneous Flora as Promising Source of Phenolic Secondary Metabolites with Health-Related Benefits.

Wild thyme aerial parts (Serpylli herba) are recognized as a valuable herbal product with antioxidant, anti-inflammatory, and antibacterial effects. Although pharmacopoeial regulations allow its collection exclusively from Thymus serpyllum, substitution with other species is frequent in current practice. This study analyzed the phenolic composition, antioxidant, and enzyme-inhibitory and antimicrobial activity of the hydroethanolic extracts obtained from five Romanian wild thyme species (Thymus alpestris, T. glabrescens, T. panonicus, T. pulcherimus and T. pulegioides). The analysis of individual phenolic constituents was performed through LC-ESI-DAD/MS2, while for the in vitro evaluation of antioxidant potential, TEAC, FRAP, DPPH, TBARS and OxHLIA assays were employed. The anti-enzymatic potential was tested in vitro against tyrosinase, α-glucosidase and acetylcholinesterase. High rosmarinic acid contents were quantified in all species (20.06 ± 0.32-80.49 ± 0.001 mg/g dry extract); phenolic acids derivatives (including salvianolic acids) were confirmed as the principal metabolites of T. alpestris and T. glabrescens, while eriodictyol-O-di-hexoside was found exclusively in T. alpestris. All species showed strong antioxidant potential and moderate anti-enzymatic effect against α-glucosidase and acetylcholinesterase, showing no anti-tyrosinase activity. This is the first detailed report on the chemical and biological profile of T. alpestris collected from Romanian spontaneous flora.

Antioxidant Capacity Fraction of the Pelawan Stems (Tristaniopsis merguensis Griff)

The impact of reactions free radical compounds can cause various health problems such as inflammation, aging, and cancer. Therefore, to avoid damage caused by free radicals, the body needs an important substance, antioxidants. Natural antioxidants are more recommended than synthetic antioxidants because synthetic antioxidants must be in accordance with the prescribed dose because they can cause side effects that are harmful to the body. This study aimed to determine the antioxidant activity of the extract and fraction of the Pelawan (Tristaniopsis merguensis Grifft.) stem extract. Antioxidant testing was carried out using the DPPH method on extracts and fractions of Pelawan stem extract (T. merguensis Grifft.). In addition, qualitative phytochemical testing was also carried out on extracts of the stems of Pelawan (T. merguensis). The results of the three solvent fractions, n-hexane, ethyl acetate, and methanol, were positive for flavonoid and phenolic secondary metabolites. Meanwhile, the antioxidant activity in reducing DPPH radicals in the methanol extract fraction of pelawan stems had a very strong activity with an IC50 value of 36.33 g/mL, while the ethyl acetate and n-hexane extract fractions had a very weak antioxidant activity with an IC50 value of 387.43 μg/mL dan 759.88 μg/mL.

The TT2-type MYB transcription factor JrMYB12 positively regulates proanthocyanidin biosynthesis in red walnut

Proanthocyanidins (PAs) are important phenolic secondary metabolites. Red walnut ‘RW-1’ is rich in PAs, but little information is available on the regulation mechanism of PA biosynthesis. Here, we reported a MYB transcription factor from ‘RW-1’, designated JrMYB12, which acted as a positive regulator in PAs accumulation. Sequence alignment showed JrMYB12 protein belongs to TT2-type R2R3 MYB transcription factor because of its TT2 domain. The expression of JrMYB12 gene was positively correlated with the accumulation of PAs and the expressions of PA-related genes (JrLAR and JrANR) in red walnut. JrMYB12 protein localized to the nuclear and showed transcriptional self-activation activity. The expression of key genes related to PA biosynthesis (AtCHS, AtDFR, AtANS, and AtANR) was up-regulated in transgenic JrMYB12 overexpression Arabidopsis lines, and the content of PAs in leaves and seed coat increased significantly. However, the overexpression of JrMYB12 gene did not cause the change of the key anthocyanin related gene AtUFGT expression in Arabidopsis. Yeast two-hybrid showed that JrMYB12 and JrbHLH42 proteins had obvious interaction, and dual-luciferase assays showed that the two proteins could form a complex to significantly enhance the promoter activity of PAs biosynthesis structural genes JrLAR and JrANR alone or together. Collectively, our research revealed the regulatory mechanism of PA biosynthesis in red walnut, and will be useful for manipulating proanthocyanidins accumulation in walnut and other plants.

ROS-Induced DNA-Damage and Autophagy in Oral Squamous Cell Carcinoma by Usnea barbata Oil Extract—An In Vitro Study

Oxidative stress is associated with aging, cancers, and numerous metabolic and chronic disorders, and phenolic compounds are well known for their health-promoting role due to their free-radical scavenging activity. These phytochemicals could also exhibit pro-oxidant effects. Due to its bioactive phenolic secondary metabolites, Usnea barbata (L.) Weber ex. F.H. Wigg (U. barbata) displays anticancer and antioxidant activities and has been used as a phytomedicine for thousands of years. The present work aims to analyze the properties of U. barbata extract in canola oil (UBO). The UBO cytotoxicity on oral squamous cell carcinoma (OSCC) CLS-354 cell line and blood cell cultures was explored through complex flow cytometry analyses regarding apoptosis, reactive oxygen species (ROS) levels, the enzymatic activity of caspase 3/7, cell cycle, nuclear shrinkage (NS), autophagy (A), and synthesis of deoxyribonucleic acid (DNA). All these studies were concomitantly performed on canola oil (CNO) to evidence the interaction of lichen metabolites with the constituents of this green solvent used for extraction. The obtained data evidenced that UBO inhibited CLS-354 oral cancer cell proliferation through ROS generation (316.67 × 104), determining higher levels of nuclear shrinkage (40.12%), cell cycle arrest in G0/G1 (92.51%; G0 is the differentiation phase, while during G1 phase occurs preparation for cell division), DNA fragmentation (2.97%), and autophagy (62.98%) than in blood cells. At a substantially higher ROS level in blood cells (5250.00 × 104), the processes that lead to cell death-NS (30.05%), cell cycle arrest in G0/G1 (86.30%), DNA fragmentation (0.72%), and autophagy (39.37%)-are considerably lower than in CLS-354 oral cancer cells. Our work reveals the ROS-mediated anticancer potential of UBO through DNA damage and autophagy. Moreover, the present study suggests that UBO pharmacological potential could result from the synergism between lichen secondary metabolites and canola oil phytoconstituents.