Metabolomics reveals the importance of metabolites in Mussaenda pubescens for antioxidant properties and quality traits.

Mussaenda pubescens (Mp) is a valuable medicinal plant that has traditionally been used for medicinal purposes or as a tea substitute. However, there are few studies on the comprehensive and dynamic evaluation of Mp metabolites. This study used an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) approach and biochemical analysis to investigate substance changes in leaves at three different stages and elucidate the relationship between metabolites and antioxidant capacity. The findings showed that Mp leaves contained 957 metabolites, the majority of which were phenolic acids, lipids, and terpenoids. The metabolite profiling of Mp leaves was significantly influenced by their growth and development at different stages. A total of 317 differentially accumulated metabolites (DAMs) were screened, including 150 primary metabolites and 167 secondary metabolites, with 202 DAMs found in bud leaf vs. tender leaf, 54 DAMs in tender leaf vs. mature leaf, and 254 DAMs in bud leaf vs. mature leaf. Total phenolics, flavonoids, and anthocyanin concentrations decreased as Mp leaves grew and developed, whereas terpenoids increased significantly. The secondary metabolites also demonstrated a positive correlation with antioxidant activity. Phenolics, flavonoids, terpenoids, and anthocyanins were the primary factors influencing the antioxidant activity of leaves. These findings provide new insights into the metabolite formation mechanism, as well as the development and utilization of Mp tea.

Bioactive Compounds and Potential Health Benefits through Cosmetic Applications of Cherry Stem Extract.

Cherry stems, prized in traditional medicine for their potent antioxidant and anti-inflammatory properties, derive their efficacy from abundant polyphenols and anthocyanins. This makes them an ideal option for addressing skin aging and diseases. This study aimed to assess the antioxidant and anti-inflammatory effects of cherry stem extract for potential skincare use. To this end, the extract was first comprehensively characterized by HPLC-ESI-qTOF-MS. The extract's total phenolic content (TPC), antioxidant capacity, radical scavenging efficiency, and its ability to inhibit enzymes related to skin aging were determined. A total of 146 compounds were annotated in the cherry stem extract. The extract effectively fought against NO· and HOCl radicals with IC50 values of 2.32 and 5.4 mg/L. Additionally, it inhibited HYALase, collagenase, and XOD enzymes with IC50 values of 7.39, 111.92, and 10 mg/L, respectively. Based on the promising results that were obtained, the extract was subsequently gently integrated into a cosmetic gel at different concentrations and subjected to further stability evaluations. The accelerated stability was assessed through temperature ramping, heating-cooling cycles, and centrifugation, while the long-term stability was evaluated by storing the formulations under light and dark conditions for three months. The gel formulation enriched with cherry stem extract exhibited good stability and compatibility for topical application. Cherry stem extract may be a valuable ingredient for creating beneficial skincare cosmeceuticals.

Integrative Metabolomic and Transcriptomic Analyses Reveal the Mechanism of Petal Blotch Formation in Rosa persica.

Petal blotch is a specific flower color pattern commonly found in angiosperm families. In particular, Rosa persica is characterized by dark red blotches at the base of yellow petals. Modern rose cultivars with blotches inherited the blotch trait from R. persica. Therefore, understanding the mechanism for blotch formation is crucial for breeding rose cultivars with various color patterns. In this study, the metabolites and genes responsible for the blotch formation in R. persica were identified for the first time through metabolomic and transcriptomic analyses using LC-MS/MS and RNA-seq. A total of 157 flavonoids were identified, with 7 anthocyanins as the major flavonoids, namely, cyanidin 3-O-(6″-O-malonyl) glucoside 5-O-glucoside, cyanidin-3-O-glucoside, cyanidin 3-O-galactoside, cyanidin O-rutinoside-O-malonylglucoside, pelargonidin 3-O-glucoside, pelargonidin 3,5-O-diglucoside, and peonidin O-rutinoside-O-malonylglucoside, contributing to pigmentation and color darkening in the blotch parts of R. persica, whereas carotenoids predominantly influenced the color formation of non-blotch parts. Zeaxanthin and antheraxanthin mainly contributed to the yellow color formation of petals at the semi-open and full bloom stages. The expression levels of two 4-coumarate: CoA ligase genes (Rbe014123 and Rbe028518), the dihydroflavonol 4-reductase gene (Rbe013916), the anthocyanidin synthase gene (Rbe016466), and UDP-flavonoid glucosyltransferase gene (Rbe026328) indicated that they might be the key structural genes affecting the formation and color of petal blotch. Correlation analysis combined with weighted gene co-expression network analysis (WGCNA) further characterized 10 transcription factors (TFs). These TFs might participate in the regulation of anthocyanin accumulation in the blotch parts of petals by modulating one or more structural genes. Our results elucidate the compounds and molecular mechanisms underlying petal blotch formation in R. persica and provide valuable candidate genes for the future genetic improvement of rose cultivars with novel flower color patterns.

Extract from Aronia melanocarpa, Lonicera caerulea, and Vaccinium myrtillus Improves near Visual Acuity in People with Presbyopia.

Presbyopia is a global problem with an estimated 1.3 billion patients worldwide. In the area of functional food applications, dietary supplements or herbs, there are very few reports describing the positive effects of their use. In the available literature, there is a lack of studies in humans as well as on an animal model of extracts containing, simultaneously, compounds from the polyphenol group (in particular, anthocyanins) and iridoids, so we undertook a study of the effects of a preparation composed of these compounds on a condition of the organ of vision. Our previous experience on a rabbit model proved the positive effect of taking an oral extract of Cornus mas in stabilizing the intraocular pressure of the eye. The purpose of this study was to evaluate the effect of an orally administered ternary compound preparation on the status of physiological parameters of the ocular organ. The preparation contained an extract of the chokeberry Aronia melanocarpa, the honeysuckle berry Lonicera caerulea L., and the bilberry Vaccinium myrtillus (hereafter AKB) standardized for anthocyanins and iridoids, as bioactive compounds known from the literature. A randomized, double-blind, cross-over study lasting with a "wash-out" period of 17 weeks evaluated a group of 23 people over the age of 50, who were subjects with presbyopia and burdened by prolonged work in front of screen monitors. The group of volunteers was recruited from people who perform white-collar jobs on a daily basis. The effects of the test substances contained in the preparation on visual acuity for distance and near, sense of contrast for distance and near, intraocular pressure, and conjunctival lubrication, tested by Schirmer test, LIPCOF index and TBUT test, and visual field test were evaluated. Anthocyanins (including cyanidin 3-O-galactoside, delphinidin 3-O-arabinoside, cyanidin 3-O-glucoside, cyanidin 3-O-rutinoside, cyanidin 3-O-arabinoside) and iridoids (including loganin, sweroside, loganic acid) were identified as substances present in the extract obtained by HPLC-MS. The preliminary results showed that the composition of AKB applied orally does not change visual acuity in the first 6 weeks of administration. Only in the next cycle of the study was an improvement in near visual acuity observed in 92.3% of the patients. This may indicate potential to correct near vision in presbyopic patients. On the other hand, an improvement in conjunctival wetting was observed in the Schirmer test at the beginning of week 6 of administration in 80% of patients. This effect was weakened in subsequent weeks of conducting the experiment to 61.5%. The improvement in conjunctival hydration in the Schirmer test shows the potential beneficial effect of the AKB formulation in a group of patients with dry eye syndrome. This is the first study of a preparation based on natural, standardized extracts of chokeberry, honeysuckle berry, and bilberry. Preliminary studies show an improvement in near visual acuity and conjunctival hydration on the Schirmer test, but this needs to be confirmed in further studies.

Effects of appropriate low-temperature treatment on the yield and quality of pigmented potato (Solanum tuberosum L.) tubers.

Temperature is one of the important environmental factors affecting plant growth, yield and quality. Moreover, appropriately low temperature is also beneficial for tuber coloration. The red potato variety Jianchuanhong, whose tuber color is susceptible to temperature, and the purple potato variety Huaxinyangyu, whose tuber color is stable, were used as experimental materials and subjected to 20 °C (control check), 15 °C and 10 °C treatments during the whole growth period. The effects of temperature treatment on the phenotype, the expression levels of structural genes related to anthocyanins and the correlations of each indicator were analyzed. The results showed that treatment at 10 °C significantly inhibited the potato plant height, and the chlorophyll content and photosynthetic parameters in the leaves were reduced, and the enzyme activities of SOD and POD were significantly increased, all indicating that the leaves were damaged. Treatment at 10 °C also affected the tuberization of Huaxinyangyu and reduced the tuberization and coloring of Jianchuanhong, while treatment at 15 °C significantly increased the stem diameter, root-to-shoot ratio, yield and content of secondary metabolites, especially anthocyanins. Similarly, the expression of structural genes were enhanced in two pigmented potatoes under low-temperature treatment conditions. In short, proper low temperature can not only increase yield but also enhance secondary metabolites production. Previous studies have not focused on the effects of appropriate low-temperature treatment during the whole growth period of potato on the changes in metabolites during tuber growth and development, these results can provide a theoretical basis and technical guidance for the selection of pigmented potatoes with better nutritional quality planting environment and the formulation of cultivation measures.

Polyphenol nanoparticles based on bioresponse for the delivery of anthocyanins.

Anthocyanin (AN) has good antioxidant and anti-inflammatory bioactivities, but its poor biocompatibility and low stability limit the application of AN in the food industry. In this study, core-shell structured carriers were constructed by noncovalent interaction using tannic acid (TA) and poloxamer 188 (F68) to improve the biocompatibility, stability and smart response of AN. Under different treatment conditions, TA-F68 and AN were mainly bound by hydrophobic interaction. The PDI is less than 0.1, and the particle size of nanoparticles (NPs) is uniform and concentrated. The retention of the complex was 15.50 % higher than that of AN alone after 9 d of light treatment. After heat treatment for 180 min, the retention rate after loading was 13.87 % higher than that of AN alone. The carrier reduce the damage of AN by the digestive environment, and intelligently and sustainedly release AN when the esterase is highly expressed. In vitro studies demonstrated that the nanocarriers had good biocompatibility and significantly inhibited the overproduction of reactive oxygen species induced by oxidative stress. In addition, AN-TA-F68 has great potential for free radical scavenging at sites of inflammation. In conclusion, the constructed nano-delivery system provides a potential application for oral ingestion of bioactive substances for intervention in ulcerative colitis.

Characterization of chemical and sensory properties of Cabernet Sauvignon and Marselan wines made by flash détente technique.

This study aimed to characterize the sensory profiles of wines produced using the flash détente (FD) technique and to identify the flavor compounds contributing to the sensory characteristics. The FD technique was applied to two major grape varieties, Cabernet Sauvignon and Marselan, from the Changli region of China to produce high-quality wines with aging potential. Compared to the traditional macerated wines, the FD wines showed greater color intensity, mainly due to the higher levels of anthocyanins. Regarding the aroma characteristics, FD wines were found to have a more pronounced fruitness, especially fresh fruit note, which was due to the contribution of higher concentration of esters. Concurrently, FD wines showed an increased sweet note which was associated with increased lactones and furanones. In addition, FD wines exhibited reduced green and floral notes due to lower levels of C6 alcohols and C13-norisoprenoids. With regard to mouthfeel, FD wines presented greater astringency and bitterness, which was due to the higher levels of phenolics. The total concentration of condensed tannins and condensed tannins for each degree of polymerization was considerably higher in FD wines due to the strong extraction of the FD technique. A significant increase in grape-derived polysaccharides and glycerol was also found in FD wines, contributing to a fuller body. This study contributed to an increase in the knowledge of the Changli region and demonstrated that the FD technique could be applied to the wine production in this region to address the negative impacts of rainfall in individual vintages.

Ultrasound pretreatment enhances moisture migration and drying quality of mulberry via microstructure and cell-wall polysaccharides nanostructure modification.

The effects of ultrasound pretreatment (20 kHz, 30 W/L) on mulberries' texture, microstructure, characteristics of cell-wall polysaccharides, moisture migration, and drying quality were investigated over exposure times ranging from 15 to 45 min. Ultrasound induced softening of mulberry tissue, accompanied by an increase in water-soluble pectin and a decrease in chelate-soluble pectin and Na2CO3-soluble pectin concentrations. Noticeable depolymerization of the pectin nanostructure was observed in the pretreated mulberries, along with a decrease in molecular weight, attributed to side-chain structure cleavage. Ultrasound loosened the cell wall structure, increased free water content and freedom, thereby reducing water diffusion resistance. Ultrasound pretreatment reduced drying time by 11.2 % to 23.3 % at various processing times compared to controls. Due to significantly enhanced drying efficiency, the optimal pretreatment time (30 min) yielded dried mulberries with higher levels of total phenolics and total anthocyanins, along with an increased antioxidant capacity. The results of this study provide insights into the mechanisms by which ultrasound pretreatment can effectively enhance the mulberry drying process.

O1/W/O2 double emulsion gels based on nanoemulsions and Pickering particles for co-encapsulating quercetin and cyanidin: A functional fat substitute.

An O1/W/O2 double emulsion gel, as a functional fat substitute and based on nanoemulsions and hydrophobic Pickering particles, is prepared by two-step emulsification to co-encapsulate hydrophilic cyanidin and hydrophobic quercetin. Nanoemulsions loading quercetin are fabricated by Tween-80 and combining high-speed and high-pressure emulsification. Phytosterol nanoparticles stabilize the W-O2 interface of the secondary emulsion to load cyanidin in the W phase. The concentration of Tween-80 is optimized as 0.3% by the droplet size and viscosity of nanoemulsions. The structural stability of double emulsion gels will be weakened along with the increase of nanoemulsions, showing lower modulus and encapsulation efficiency (EE) and bigger droplets. In double emulsion gels, the EE of quercetin and cyanidin reaches 93% and 85.6%, respectively. Analysis of molecular interaction indicates that Tween-80 would decrease the in-situ hydrophobicity of phytosterol nanoparticles by hydrogen bonding adsorption, thereby weakening the emulsification. The pH-chromic 3D printing of double emulsion gels is designed according to the pH sensitivity of cyanidin. Texture profile analysis is performed to test the textural properties of 3D-printed objects. The simulated digestion is conducted on double emulsion gels. The double emulsion gel with fewer nanoemulsions is beneficial for protecting quercetin and improving the delivery due to the higher structural stability, while that with more nanoemulsions is conducive to the digestion of cyanidin and camellia oil due to weakened semi-solid properties. This double emulsion gel further simulates fat tissues by co-encapsulating hydrophilic and hydrophobic substances, promoting the application of fat substitutes in the food industry.

Ion presence during thermal processing modulates the performance of rice albumin/anthocyanin binary system.

Thermal processing with salt ions is widely used for the production of food products (such as whole grain food) containing protein and anthocyanin. To date, it is largely unexplored how salt ion presence during thermal processing regulates the practical performance of protein/anthocyanin binary system. Here, rice albumin (RA) and black rice anthocyanins (BRA) were used to prepare RA/BRA composite systems as a function of temperature (60-100 °C) and NaCl concentration (10-40 mM) or CaCl2 concentration (20 mM). It was revealed that the spontaneous complexing reaction between RA and BRA was driven by hydrophobic interactions and hydrogen bonds and becomes easier and more favorable at a higher temperature (≤90 °C), excessive temperature (100 °C), however, may result in the degradation of BRA. Moreover, the salt ion presence during thermal processing may bind with RA and BRA, respectively, which could restrict the interaction between BRA and RA. Additionally, the inclusion of Na+ or Ca2+ at 20 mM endowed the binary system with strengthened DPPH radical scavenging capacity (0.95 for Na+ and 0.99 for Ca2+). Notably, Ca2+ performed a greater impact on the stability of the system than Na+.

Hormonal response to recurrent seasonal stress in coastal and mountain scabiouses growing in their natural habitat: linking ABA and jasmonates with photoprotection.

Plant species distribution across ecosystems is influenced by multiple environmental factors, and recurrent seasonal stress events can act as natural selection agents for specific plant traits and limit species distribution. For that, studies aiming at understanding how environmental constraints affect adaptive mechanisms of taxonomically closely related species are of great interest. We chose two Scabiosa species inhabiting contrasting environments: the coastal scabious S. atropurpurea, typically coping with hot-dry summers in a Mediterranean climate, and the mountain scabious S. columbaria facing cold winters in an oceanic climate. A set of functional traits was examined to assess plant performance in these congeneric species from contrasting natural habitats. Both S. atropurpurea and S. columbaria appeared to be perfectly adapted to their environment in terms of adjustments in stomatal closure, CO2 assimilation rate and water use efficiency over the seasons. However, an unexpected dry period during winter followed by the typical Mediterranean hot-dry summer forced S. atropurpurea plants to deploy a set of photoprotective responses during summer. Aside from reductions in leaf water content and Fv/Fm, photoprotective molecules (carotenoids, α-tocopherol and anthocyanins) per unit of chlorophyll increased, mostly as a consequence of a severe chlorophyll loss. The profiling of stress-related hormones (ABA, salicylic acid and jasmonates) revealed associations between ABA and the bioactive jasmonoyl-isoleucine with the underlying photoprotective response to recurrent seasonal stress in S. atropurpurea. We conclude that jasmonates may be used together with ABA as a functional trait that may, at least in part, help understand plant responses to recurrent seasonal stress in the current frame of global climate change.

Genome-wide characterization of SmZHD gene family and the role of SmZHD12 in regulating anthocyanin biosynthesis in eggplant (Solanum melongena L.).

KEY MESSAGE: SmZHDs was highly expressed in anthocyanin-rich parts of eggplant. SmZHD12 can activate the expression of SmCHS, SmANS, SmDFR and SmF3H. Overexpression of SmZHD12 promotes anthocyanin biosynthesis in Arabidopsis. The Zinc finger-homeodomain (ZHD) proteins family genes are known to play a significant role in plant development and physiological processes. However, the evolutionary history and function of the ZHD gene family in eggplant remain largely unexplored. This study categorizes a total of 15 SmZHD genes into SmMIF and SmZHD subfamilies based on conserved domains. The phylogeny, gene structure, conserved motifs, promoter elements, and chromosomal locations of the SmZHD genes were comprehensively analyzed. Tissue expression profiles indicate that the majority of SmZHD genes are expressed in anthocyanin-rich areas. qRT-PCR assays revealed distinct expression patterns of SmZHD genes in response to various treatments, indicating their potential involvement in multiple signaling pathways. Analysis of transcriptomic data from light-treated eggplant peel identified SmZHD12 as the most light-responsive gene among the 15 SmZHD genes. Consequently, this study provides further evidence that SmZHD12 facilitates anthocyanin accumulation in Arabidopsis leaves by upregulating the expression of anthocyanin biosynthesis structural genes, as confirmed by dual-luciferase assays and Arabidopsis genetic transformation. Our study will lay a solid foundation for the in-depth study of the involvement of SmZHD genes in the regulation of anthocyanin biosynthesis.

Anthocyanins: Quantification by Tandem Mass Spectrometry.

Mass spectrometry is a high throughput technique widely used for metabolic fingerprinting of plant material. Among the diverse plant metabolites, pigments such as anthocyanins play a determinant role in plant defence mechanisms, protecting them from biotic and abiotic stresses. Anthocyanins are phenolic water-soluble glycosides or acyl-glycosides of anthocyanidins which could be accurately detected and quantified through mass spectrometry. This chapter describes how to extract anthocyanins from higher plant materials and quantify them through a liquid chromatography-mass spectrometry (LC-MS) based method.

Vineyard microclimate alterations induced by black inter-row mulch through transcriptome reshaped the flavoromics of cabernet sauvignon grapes.

BACKGROUND: Weed control is essential for agricultural floor management in vineyards and the inter-row mulching is an eco-friendly practice to inhibit weed growth via filtering out photosynthetically active radiation. Besides weed suppression, inter-row mulching can influence grapevine growth and the accumulation of metabolites in grape berries. However, the complex interaction of multiple factors in the field challenges the understanding of molecular mechanisms on the regulated metabolites. In the current study, black geotextile inter-row mulch (M) was applied for two vintages (2016-2017) from anthesis to harvest. Metabolomics and transcriptomics analysis were conducted in two vintages, aiming to provide insights into metabolic and molecular responses of Cabernet Sauvignon grapes to M in a semi-arid climate. RESULTS: Upregulation of genes related to photosynthesis and heat shock proteins confirmed that M weakened the total light exposure and grapes suffered heat stress, resulting in lower sugar-acid ratio at harvest. Key genes responsible for enhancements in phenylalanine, glutamine, ornithine, arginine, and C6 alcohol concentrations, and the downward trend in ε-viniferin, anthocyanins, flavonols, terpenes, and norisoprenoids in M grapes were identified. In addition, several modules significantly correlated with the metabolic biomarkers through weighted correlation network analysis, and the potential key transcription factors regulating the above metabolites including VviGATA11, VviHSFA6B, and VviWRKY03 were also identified. CONCLUSION: This study provides a valuable overview of metabolic and transcriptomic responses of M grapes in semi-arid climates, which could facilitate understanding the complex regulatory network of metabolites in response to microclimate changes.

An anthocyanin-rich extract from Zea mays L. var. ceratina alleviates neuronal cell death caused by hydrogen peroxide-induced cytotoxicity in SH-SY5Y cells.

The incidence of dementia is rising, with neuronal cell death from oxidative stress and apoptosis recognized as a significant contributor to its development. However, effective strategies to combat this condition are lacking, necessitating further investigation. This study aimed to assess the potential of an anthocyanin-rich extract from Zea mays L. var. ceratina (AZC) in alleviating neuronal cell death.Neurotoxicity was induced in SH-SY5Y cells using hydrogen peroxide (H2O2) at a concentration of 200 µM. Cells were pretreated with varying doses (31.25 and 62.5 µg/mL) of AZC. Cell viability was assessed using the MTT assay, and molecular mechanisms including reactive oxygen species (ROS) levels, antioxidant enzyme activities (catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px)), malondialdehyde (MDA) levels for oxidative stress, and the activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2), cAMP response element-binding protein (CREB), and apoptotic factors (B-cell lymphoma 2 (Bcl-2), caspase 3) were explored.Results showed that AZC significantly improved cell viability, reduced ROS production and MDA levels, and downregulated caspase 3 expression. It enhanced CAT, SOD, and GSH-Px activities, activated ERK1/2 and CREB, and upregulated Bcl-2 expression. These findings support the neuroprotective effects of AZC, suggesting it activates ERK1/2, leading to CREB activation and subsequent upregulation of Bcl-2 expression while suppressing caspase 3. AZC may mitigate neuronal cell death by reducing ROS levels through enhanced scavenging enzyme activities.In conclusion, this study underscores the potential of AZC as a neuroprotective agent against neuronal cell death. However, further investigations including toxicity assessments, in vivo studies, and clinical trials are necessary to validate its benefits in neuroprotection.

Foliar-applied silicate potassium modulates growth, phytochemical, and physiological traits in Cichorium intybus L. under salinity stress.

One of the major problems endangering plant growth and productivity worldwide is salt stress. This study aimed to assess the effects of potassium silicate (K2O3Si) on the physical, biochemical, and morphological characteristics of chicory (Cichorium intybus L.) under various levels of salinity stress. The plants were treated with K2O3Si at concentrations of 0, 1, 2, and 3 mM and cultivated under different salt stress conditions (0, 80, 160, and 240 mM NaCl). The findings revealed that salt stress led to decreased root and shoot dry weights, Fv/Fm ratio, chlorophyll a, b, and total chlorophyll, as well as inulin contents. However, foliar exposure to K2O3Si at all salinity levels resulted in improvements in the measured traits. As salinity levels increased, there was a corresponding increase in the accumulation of sodium ions (Na+) and a sharp reduction in potassium ions (K +) in the shoot. Nonetheless, treatment with K2O3Si caused a decrease in Na + accumulation and an improvement in K+ content under all salinity levels. Carotenoid content increased under 80 mM salinity stress, but decreased with higher salinity levels. Application of K2O3Si at all levels resulted in increased carotenoid content under salinity stress conditions. The content of MDA increased significantly with increasing salinity stress, particularly at 240 mM. However, foliar spraying with K2O3Si significantly decreased MDA content at all salinity levels. Salinity stress up to 160 mM increased the total phenol, flavonoid, and anthocyanin contents, while 240 mM NaCl decreased the biosynthesis of phytochemicals. Additionally, the use of K2O3Si increased the content of total phenol, flavonoid, and anthocyanin at all salt levels. Foliar application of K2O3Si increased the tolerance of chicory plants to salinity stress by reducing MDA and increasing phenolic compounds and potassium content. These results suggest that exogenous K2O3Si can be a practical strategy to improve the growth and yield of chicory plants exposed to saline environments.

The R2R3-MYB transcription factor ZeMYB32 negatively regulates anthocyanin biosynthesis in Zinnia elegans.

KEY MESSAGE: This study identified an R2R3-MYB from Zinnia elegans, ZeMYB32, which negatively regulates anthocyanin biosynthesis.

Transcriptome, Plant Hormone, and Metabolome Analysis Reveals the Mechanism of Purple Pericarp Formation in 'Zihui' Papaya (Carica papaya L.).

The color of the pericarp is a crucial characteristic that influences the marketability of papaya fruit. Prior to ripening, normal papaya exhibits a green pericarp, whereas the cultivar 'Zihui' displays purple ring spots on the fruit tip, which significantly affects the fruit's visual appeal. To understand the mechanism behind the formation of purple pericarp, this study performed a thorough examination of the transcriptome, plant hormone, and metabolome. Based on the UPLC-ESI-MS/MS system, a total of 35 anthocyanins and 11 plant hormones were identified, with 27 anthocyanins and two plant hormones exhibiting higher levels of abundance in the purple pericarp. In the purple pericarp, 14 anthocyanin synthesis genes were up-regulated, including CHS, CHI, F3H, F3'5'H, F3'H, ANS, OMT, and CYP73A. Additionally, through co-expression network analysis, three MYBs were identified as potential key regulators of anthocyanin synthesis by controlling genes encoding anthocyanin biosynthesis. As a result, we have identified numerous key genes involved in anthocyanin synthesis and developed new insights into how the purple pericarp of papaya is formed.

Isolation, Purification and Tyrosinase Inhibitory Activity of Anthocyanins and Their Novel Degradation Compounds from Solanum tuberosum L.

To explore the composition of anthocyanins and expand their biological activities, anthocyanins were systematically isolated and purified from tubers of Solanum tuberosum L., and their tyrosinase inhibitory activity was investigated. In this study, two new anthocyanin degradation compounds, norpetanin (9) and 4-O-(p-coumaryl) rhamnose (10), along with 17 known anthocyanins and their derivatives, were isolated and purified from an acid-ethanolic extract of fresh purple potato tubers. Their structures were elucidated via 1D and 2D NMR and HR-ESI-MS and compared with those reported in the literature. The extracts were evaluated for anthocyanins and their derivatives using a tyrosinase inhibitor screening kit and molecular docking technology, and the results showed that petanin, norpetanin, 4-O-(p-coumaryl) rhamnose, and lyciruthephenylpropanoid D/E possessed tyrosinase inhibitory activity, with 50% inhibiting concentration (IC50) values of 122.37 ± 8.03, 115.53 ± 7.51, 335.03 ± 12.99, and 156.27 ± 11.22 µM (Mean ± SEM, n = 3), respectively. Furthermore, petanin was validated against melanogenesis in zebrafish; it was found that it could significantly inhibit melanin pigmentation (p < 0.001), and the inhibition rate of melanin was 17% compared with the normal group. This finding may provide potential treatments for diseases with abnormal melanin production, and high-quality raw materials for whitening cosmetics.

Kaempferol 3-O-Rutinoside, a Flavone Derived from Tetrastigma hemsleyanum Diels et Gilg, Reduces Body Temperature through Accelerating the Elimination of IL-6 and TNF-α in a Mouse Fever Model.

Fever is a serious condition that can lead to various consequences ranging from prolonged illness to death. Tetrastigma hemsleyanum Diels et Gilg (T. hemsleyanum) has been used for centuries to treat fever, but the specific chemicals responsible for its antipyretic effects are not well understood. This study aimed to isolate and identify the chemicals with antipyretic bioactivity in T. hemsleyanum extracts and to provide an explanation for the use of T. hemsleyanum as a Chinese herbal medicine for fever treatment. Our results demonstrate that kaempferol 3-rutinoside (K3OR) could be successfully isolated and purified from the roots of T. hemsleyanum. Furthermore, K3OR exhibited a significant reduction in rectal temperature in a mouse model of fever. Notably, a 4 µM concentration of K3OR showed more effective antipyretic effects than ibuprofen and acetaminophen. To explore the underlying mechanism, we conducted an RNA sequencing analysis, which revealed that PXN may act as a key regulator in the fever process induced by lipopolysaccharide (LPS). In the mouse model of fever, K3OR significantly promoted the secretion of IL-6 and TNF-α during the early stage in the LPS-treated group. However, during the middle to late stages, K3OR facilitated the elimination of IL-6 and TNF-α in the LPS-treated group. Overall, our study successfully identified the chemicals responsible for the antipyretic bioactivity in T. hemsleyanum extracts, and it answered the question as to why T. hemsleyanum is used as a traditional Chinese herbal medicine for treating fever. These findings contribute to a better understanding of the therapeutic potential of T. hemsleyanum in managing fever, and they provide a basis for further research and development in this field.