Flavonoids in vegetables: improvement of dietary flavonoids by metabolic engineering to promote health

WRKY33 negatively regulates anthocyanin biosynthesis and cooperates with PHR1 to mediate acclimation to phosphate starvation

Anthocyanin accumulation is acknowledged as a phenotypic indicator of phosphate (Pi) starvation. However, negative regulators of this process and their molecular mechanisms remain largely unexplored. In this study, we demonstrate that WRKY33 acts as a negative regulator of phosphorus-status-dependent anthocyanin biosynthesis. WRKY33 regulates the expression of the gene encoding dihydroflavonol 4-reductase (DFR), a rate-limiting enzyme in anthocyanin production, both directly and indirectly. WRKY33 binds directly to the DFR promoter to repress its expression and also interferes with the MBW complex through interacting with PAP1 to indirectly influence DFR transcriptional activation. Under -Pi conditions, PHR1 interacts with WRKY33, and the protein level of WRKY33 decreases; the repression of DFR expression by WRKY33 is thus attenuated, leading to anthocyanin accumulation in Arabidopsis. Further genetic and biochemical assays suggest that PHR1 is also involved in regulating factors that affect WRKY33 protein turnover. Taken together, our findings reveal that Pi starvation represses WRKY33, a repressor of anthocyanin biosynthesis, to finely tune anthocyanin biosynthesis. This "double-negative logic" regulation of phosphorus-status-dependent anthocyanin biosynthesis is required for the maintenance of plant metabolic homeostasis during acclimation to Pi starvation.

Cross-sectional and longitudinal associations between empirically derived dietary patterns and frailty among older men: The Concord Health and Ageing in Men Project

BACKGROUND

Diet may be associated with frailty.

OBJECTIVE

We aimed to evaluate the associations between empirically derived dietary patterns and frailty in older men.

DESIGN

Prospective cohort study.

SETTING

The Concord Health and Ageing in Men Project, Sydney, Australia.

PARTICIPANTS

785 community-dwelling older Australian men aged 75 years and older.

METHODS

Men underwent dietary assessment using a validated dietitian-administered diet history questionnaire. Factor analysis identified three dietary patterns. Multinomial logistic regression was conducted between frailty and dietary patterns for cross-sectional analyses and longitudinal analyses over a 3-year follow-up. Frailty was defined by the Fried frailty phenotype.

RESULTS

Of the 785 men, pre-frailty was prevalent in 47.1% (n = 370), and frailty in 8.3% (n = 65). In fully adjusted cross-sectional analyses, the top tertile and a higher 'vegetables-legumes-seafood' dietary pattern score were associated with reduced prevalence of frailty (OR 0.34 [95% CI: 0.12, 0.93, P = .036]) and OR 0.50 [95% CI: 0.30, 0.83, P = .007] respectively). The top tertile of the 'discretionary-starchy vegetables-processed meats' dietary pattern was also associated cross-sectionally with increased prevalence of pre-frailty (OR 1.75 [95% CI: 1.08, 2.83, P = .022]). Of the 296 robust men in fully adjusted longitudinal analyses, the incidence of pre-frailty was 52.4% (n = 155), and frailty was 5.4% (n = 16) over a 3-year follow-up. The middle tertile of the 'vegetables-legumes-seafood' dietary pattern had a non-significant trend towards reduced incident pre-frailty (OR 0.52 [95% CI: 0.27, 1.00, P = .050]).

CONCLUSION

Consumption of a 'vegetables-legumes-seafood' dietary pattern appears to be less favoured by frail older men.

Instant Protection Spray for Anti-Infection and Accelerated Healing of Empyrosis

Distinct from common injuries, deep burns often require a chronic recovery cycle for healing and long-term antibiotic treatment to prevent infection. The rise of drug-resistant bacteria has caused antibiotics to no longer be perfect, and continuous drug use can easily lead to repeated infection and even death. Inspired by wild animals that chew plants to prevent wound infection, probiotic extracts with a structure similar to the tailspike of phage are obtained from Lactobacillus casei and combined with different flavones to design a series of nonantibiotic bactericides. These novel antibacterial agents are combined with a rapid gelation spray with a novel cross-angle layout to form an instant protection spray (IPS) and provide a physical and anti-infectious barrier for burns within 30 s. This IPS is able to sterilize 100.00% and 96.14% of multidrug-resistant Staphylococcus aureus (MRSA) in vitro and in vivo, respectively. In addition, it is found to effectively reduce inflammation in MRSA-infected burns in rats and to promote tissue healing.

Multi-Omics Analyses Unravel Metabolic and Transcriptional Differences in Tender Shoots from Two Sechium edule Varieties

Chaylte vine, the tender shoot of Sechium edule, is popular among vegetable consumers because of its high nutritional content, crisp texture, and unique flavor. Existing studies on the nutrient composition of chaylte vines are mostly simple chemical determinations, which have limited the breeding of specialized cultivars and the development of related industries. Using metabolomics combined with transcriptomics, this study analyzed the metabolic characteristics and related molecular mechanisms of two common varieties of chaylte vines: green-skinned (SG) and white-skinned (SW). Between the two varieties, a total of 277 differentially accumulated metabolites (DAMs) and 739 differentially expressed genes (DEGs) were identified. Furthermore, chemical assays demonstrated that the SW exhibited a higher total flavonoid content and antioxidant capacity. In conclusion, it was found that the SG samples exhibited a higher diversity of flavonoid subclasses compared to the SW samples, despite having a lower total flavonoid content. This inconsistent finding was likely due to the differential expression of the phenylalanine ammonia-lyase (PAL) and chalcone synthase (CHS) genes in the two varieties. These results laid the foundation for investigating the mechanisms involved in flavonoid regulation and the breeding of specialized S. edule cultivars for chaylte vine production.

Characterization of color variation in bamboo sheath of Chimonobambusa hejiangensis by UPLC-ESI-MS/MS and RNA sequencing

BACKGROUND

Chimonobambusa hejiangensis (C.hejiangensis) is a high-quality bamboo species native to China, known for its shoots that are a popular nutritional food. Three C.hejiangensis cultivars exhibit unique color variation in their shoot sheaths, however, the molecular mechanism behind this color change remains unclear.

METHODS

We investigated flavonoid accumulation in the three bamboo cultivar sheaths using metabolomics and transcriptomics.

RESULTS

UPLC-MS/MS identified 969 metabolites, with 187, 103, and 132 having differential accumulation in the yellow-sheath (YShe) vs. spot-sheath (SShe)/black-sheath (BShe) and SShe vs. BShe comparison groups. Flavonoids were the major metabolites that determined bamboo sheath color through differential accumulation of metabolites (DAMs) analysis. Additionally, there were 33 significantly differentially expressed flavonoid structural genes involved in the anthocyanin synthesis pathway based on transcriptome data. We conducted a KEGG analysis on DEGs and DAMs, revealing significant enrichment of phenylpropanoid and flavonoid biosynthetic pathways. Using gene co-expression network analysis, we identified nine structural genes and 29 transcription factors strongly linked to anthocyanin biosynthesis.

CONCLUSION

We identified a comprehensive regulatory network for flavonoid biosynthesis which should improve our comprehension of the molecular mechanisms responsible for color variation and flavonoid biosynthesis in bamboo sheaths.

Selected Flavonols in Breast and Gynecological Cancer: A Systematic Review

The consumption of foods that are rich in phenolic compounds has chemopreventive effects on many cancers, including breast cancer, ovarian cancer, and endometrial cancer. A wide spectrum of their health-promoting properties such as antioxidant, anti-inflammatory, and anticancer activities, has been demonstrated. This paper analyzes the mechanisms of the anticancer action of selected common flavonols, including kemferol, myricetin, quercetin, fisetin, galangin, isorhamnetin, and morin, in preclinical studies, with particular emphasis on in vitro studies in gynecological cancers and breast cancer. In the future, these compounds may find applications in the prevention and treatment of gynecological cancers and breast cancer, but this requires further, more advanced research.

Fluorescence enhancement of flavonoids and its application in ingredient determination for some traditional Chinese medicines by CE-LIF

Flavonoids are widely used in the treatment of various diseases due to their antioxidant, anti-inflammatory, anticancer and antiviral properties. Fluorescence detection is rarely applied for the determination of flavonoids because of their weak fluorescence. In this work, a method of fluorescence enhancement of flavonoids was firstly introduced by using sodium acetate for flavonoid derivatization. The study discovered that flavonoids, with a hydroxyl at the C3 position, had the ability to emit strong fluorescence after derivatization. Five flavonoids, kaempferide, galangin, isorhamnetin, kaempferol and quercetin, having a special structure, were selected, derivatized and analyzed by capillary electrophoresis with laser-induced fluorescence detection. Under the optimal conditions, the five flavonoids could be completely separated within 3 minutes. Good linear relationships were obtained for all analytes and the limits of detection for the five flavonoids were in the range of 1.18-4.67 × 10^-7 mol L^-1. Finally, the method was applied to the determination of flavonoids in five traditional Chinese medicines: aster, chamomile, galangal, tangerine peel and cacumen biotae. Flavonoids were successfully found in all these medicines by the developed method. The recoveries were in the range of 84.2-111%. The method developed in this study was fast, sensitive and reliable for the determination of flavonoids.

Structures, Sources, Identification/Quantification Methods, Health Benefits, Bioaccessibility, and Products of Isorhamnetin Glycosides as Phytonutrients

In recent years, people have tended to consume phytonutrients and nutrients in their daily diets. Isorhamnetin glycosides (IGs) are an essential class of flavonoids derived from dietary and medicinal plants such as Opuntia ficus-indica, Hippophae rhamnoides, and Ginkgo biloba. This review summarizes the structures, sources, quantitative and qualitative analysis technologies, health benefits, bioaccessibility, and marketed products of IGs. Routine and innovative assay methods, such as IR, TLC, NMR, UV, MS, HPLC, UPLC, and HSCCC, have been widely used for the characterization and quantification of IGs. All of the therapeutic effects of IGs discovered to date are collected and discussed in this study, with an emphasis on the relevant mechanisms of their health-promoting effects. IGs exhibit diverse biological activities against cancer, diabetes, hepatic diseases, obesity, and thrombosis. They exert therapeutic effects through multiple networks of underlying molecular signaling pathways. Owing to these benefits, IGs could be utilized to make foods and functional foods. IGs exhibit higher bioaccessibility and plasma concentrations and longer average residence time in blood than aglycones. Overall, IGs as phytonutrients are very promising and have excellent application potential.

Modulating Inflammation-Mediated Diseases via Natural Phenolic Compounds Loaded in Nanocarrier Systems

The global increase and prevalence of inflammatory-mediated diseases have been a great menace to human welfare. Several works have demonstrated the anti-inflammatory potentials of natural polyphenolic compounds, including flavonoid derivatives (EGCG, rutin, apigenin, naringenin) and phenolic acids (GA, CA, etc.), among others (resveratrol, curcumin, etc.). In order to improve the stability and bioavailability of these natural polyphenolic compounds, their recent loading applications in both organic (liposomes, micelles, dendrimers, etc.) and inorganic (mesoporous silica, heavy metals, etc.) nanocarrier technologies are being employed. A great number of studies have highlighted that, apart from improving their stability and bioavailability, nanocarrier systems also enhance their target delivery, while reducing drug toxicity and adverse effects. This review article, therefore, covers the recent advances in the drug delivery of anti-inflammatory agents loaded with natural polyphenolics by the application of both organic and inorganic nanocarriers. Even though nanocarrier technology offers a variety of possible anti-inflammatory advantages to naturally occurring polyphenols, the complexes' inherent properties and mechanisms of action have not yet been fully investigated. Thus, expanding the quest on novel natural polyphenolic-loaded delivery systems, together with the optimization of complexes' activity toward inflammation, will be a new direction of future efforts.