Search Results (307)

Stevia rebaudiana leaves and extracts need to be promptly dried after harvest to prevent microbial activity and preserve their bioactive compounds, including glycosides, flavonoids, and essential oils. Effective drying also reduces moisture and volume, which lowers packaging, storage, and transportation costs. Therefore, innovative drying methods are necessary to maintain stevia’s physicochemical, sensory, and nutritional properties for functional food formulations. This review evaluates various drying technologies for stevia leaves and extracts, including convective hot air, infrared, vacuum, microwave, freeze, and shade drying, and their impacts on product quality and energy efficiency. It also explores the growing applications of dried and extracted stevia in food products. By comparing different drying methods and highlighting the benefits of stevia in these food formulations, this investigation aims to identify future research directions and optimization strategies for utilizing stevia as a natural sweetener and functional ingredient. Convective hot air drying at higher temperatures was found to be the most energy-efficient, though several studies have reported moderate degradation of key bioactive compounds such as stevioside and rebaudioside A, particularly at elevated temperatures and extended drying times. Infrared drying enhanced antimicrobial activity but resulted in lower levels of polyphenols and antioxidants. Vacuum drying effectively preserved anti-inflammatory compounds like flavonoids. Microwave drying presented strong protection of antioxidant activity and superior particle morphology. Freeze drying, while less energy-efficient, was the most effective at retaining antioxidants, polyphenols, and volatile compounds. Shade drying, though time-consuming, maintained high levels of polyphenols, flavonoids, and essential oils. Advanced techniques like spray drying and electrospraying have been reported to enhance the sensory qualities and stability of stevia extracts, making them ideal for food applications such as dairy and baked products, confectionery, syrups, snacks, jams, preserves, and meat products. Overall, stevia not only serves as a natural, zero-calorie sweetener but also contributes to improved health benefits and product quality in these diverse food formulations. Full article

Studies utilizing cell-based systems to investigate plant-based diets for diabetes management are gaining attention due to the adverse effects associated with commercially available drugs. However, the molecular mechanisms underlying the anti-diabetic effects of specific plant-derived products remain inadequately explored. The major aim of our study was to elucidate the molecular mechanisms by which bioactive compounds in the fruit of Solanum spp. influence key proteins associated with type 2 diabetes. The expressions of genes such as glucose transporter protein 4 (GLUT4), myocyte enhancer factor-2 (MEF-2A), and nuclear respiratory factor-1 (NRF-1) were investigated in a palmitate-induced C2C12 cell model of type 2 diabetes mellitus. The structures of these proteins were retrieved from the protein database, while bioactive compounds previously identified in Solanum spp. were obtained from PubChem site. Drug-likeness properties of these compounds (ligands) were assessed. The docked protein-ligand complexes were further analyzed using the Protein-Ligand Profiler web server. Our results showed that the studied compounds from Solanum spp. profoundly upregulated GLUT4 expression (9–19-fold increase) in the C2C12 cell line, thus surpassing the effects of the standard anti-diabetic drug metformin. Additionally, activities of antioxidant enzymes catalase, superoxide dismutase, and glutathione peroxidase were elevated. Molecular docking showed that rutin, an abundant flavonoid from Solanum spp., had the highest binding affinity for the active sites of the target proteins. These findings provide new mechanistic insight into the anti-diabetic effects of Solanum spp., primarily due to its high rutin content, which plays a major role in the plant’s glucose-regulating and antioxidant actions. Our findings underscore the potential use of Solanum spp. as an affordable functional food for managing type 2 diabetes, especially in developing countries with limited resources for purchasing drugs. Although promising, our findings should be further validated by clinical studies. Full article

Flavonoids constitute a broad class of naturally occurring chemical compounds classified as polyphenols, widely present in various plants, fruits, and vegetables. They share a common flavone backbone, composed of two aromatic rings (A and B) connected by a three-carbon bridge forming a heterocyclic ring (C). One representative flavonoid is chrysin, a compound found in honey, propolis, and passionflower (Passiflora spp.). Chrysin exhibits a range of biological activities, including antioxidant, anti-inflammatory, anticancer, neuroprotective, and anxiolytic effects. Its biological activity is primarily attributed to the presence of hydroxyl groups, which facilitate the neutralization of free radicals and the modulation of intracellular signaling pathways. Cellular uptake of chrysin and other flavonoids occurs mainly through passive diffusion; however, certain forms may be transported via specific membrane-associated carrier proteins. Despite its therapeutic potential, chrysin’s bioavailability is significantly limited due to poor aqueous solubility and rapid metabolism in the gastrointestinal tract and liver, which reduces its systemic efficacy. Ongoing research aims to enhance chrysin’s bioavailability through the development of delivery systems such as lipid-based carriers and nanoparticles. Full article

Quercetin is a biologically active flavonoid compound that exerts numerous beneficial effects in humans and animals, including anti-diabetic activity. Its action has been explored in rodent models of type 1 and type 2 diabetes. It was revealed that quercetin mitigated diabetes-related hormonal and metabolic disorders and reduced oxidative and inflammatory stress. Its anti-diabetic effects were associated with advantageous changes in the relevant enzymes and signaling molecules. Quercetin positively affected, among others, superoxide dismutase, catalase, glutathione peroxidase, glucose transporter-2, glucokinase, glucose-6-phosphatase, glycogen phosphorylase, glycogen synthase, glycogen synthase kinase-3β, phosphoenolpyruvate carboxykinase, silent information regulator-1, sterol regulatory element-binding protein-1, insulin receptor substrate 1, phosphoinositide 3-kinase, and protein kinase B. The available data support the conclusion that the action of quercetin was pleiotropic since it alleviates a wide range of diabetes-related disorders. Moreover, no side effects were observed during treatment with quercetin in rodents. Given that human diabetes affects a large part of the population worldwide, the results of animal studies encourage clinical trials to evaluate the potential of quercetin as an adjunct to pharmacological therapies. Full article

Background/Objectives: Sweet potato is a tropical and subtropical crop and its growth and yield are susceptible to low-temperature stress. However, the molecular mechanisms underlying the low temperature stress of sweetpotato are unknown. Methods: In this work, combined transcriptome and metabolism analysis was employed to investigate the low-temperature responses of two sweet potato cultivars, namely, the low-temperature-resistant cultivar “X33” and the low-temperature-sensitive cultivar “W7”. Results: The differentially expressed metabolites (DEMs) of X33 at different time stages clustered in five profiles, while they clustered in four profiles of W7 with significant differences. Differentially expressed genes (DEGs) in X33 and W7 at different time points clustered in five profiles. More DEGs exhibited continuous or persistent positive responses to low-temperature stress in X33 than in W7. There were 1918 continuously upregulated genes and 6410 persistent upregulated genes in X33, whereas 1781 and 5804 were found in W7, respectively. Core genes involved in Ca²⁺ signaling, MAPK cascades, the reactive oxygen species (ROS) signaling pathway, and transcription factor families (including bHLH, NAC, and WRKY) may play significant roles in response to low temperature in sweet potato. Thirty-one common differentially expressed metabolites (DEMs) were identified in the two cultivars in response to low temperature. The KEGG analysis of these common DEMs mainly belonged to isoquinoline alkaloid biosynthesis, phosphonate and phosphinate metabolism, flavonoid biosynthesis, cysteine and methionine metabolism, glycine, serine, and threonine metabolism, ABC transporters, and glycerophospholipid metabolism. Five DEMs with identified Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were selected for correlation analysis. KEGG enrichment analysis showed that the carbohydrate metabolism, phenylpropanoid metabolism, and glutathione metabolism pathways were significantly enriched and played vital roles in low-temperature resistance in sweet potato. Conclusions: These findings contribute to a deeper understanding of the molecular mechanisms underlying plant cold tolerance and offer targets for molecular breeding efforts to enhance low-temperature resistance. Full article

Hyperlipidemia (HLP) is a disorder of human lipid metabolism or transport, primarily characterized by abnormally elevated levels of total cholesterol (TC), triglycerides (TGs), and low-density lipoprotein cholesterol (LDL-C) in the blood. It is a key factor contributing to the development of non-alcoholic fatty liver disease, obesity, diabetes, atherosclerosis, and cardiovascular and cerebrovascular diseases. Statistics show that the prevalence of dyslipidemia among Chinese adults is as high as 35.6%, and it has shown a trend of younger onset in recent years, posing a serious threat to public health. Therefore, the prevention and treatment of dyslipidemia carry significant social significance. The pathogenesis of hyperlipidemia is complex and diverse, and currently used medications are often accompanied by side effects during treatment, making the research and development of new therapeutic approaches a current focus. Numerous studies have shown that flavonoids, which are abundant in most medicinal plants, fruits, and vegetables, exert effects on regulating lipid homeostasis and treating hyperlipidemia through a multi-target mechanism. These compounds have demonstrated significant effects in inhibiting lipid synthesis, blocking lipid absorption, promoting cholesterol uptake, enhancing reverse cholesterol transport, and suppressing oxidative stress, inflammation, and intestinal microbiota disorders. This article reviews the latest progress in the mechanisms of flavonoids in the treatment of hyperlipidemia, providing a theoretical basis for future research on drugs for hyperlipidemia. Full article

Low temperature is a major abiotic stress affecting rice productivity. Selenium (Se) treatment has been shown to enhance plant resilience to cold stress. In this study, low concentrations of selenium (ColdSe1) alleviated the adverse effects of cold stress on rice seedlings, improving fresh weight, plant height, and chlorophyll content by 36.9%, 24.3%, and 8.4%, respectively, while reducing malondialdehyde (MDA) content by 29.1%. Se treatment also increased the activities of antioxidant enzymes, including catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD), by 25.2%, 42.7%, and 33.3%, respectively, and upregulated flavonoids, soluble sugars, cysteine (Cys), glutathione (GSH), and oxidized glutathione (GSSG). Transcriptome analysis revealed that ColdSe1 treatment upregulated genes associated with amino and nucleotide sugar metabolism, glutathione metabolism, and fructose and mannose metabolism. It also alleviated cold stress by modulating the MAPK signaling pathway, phytohormone signaling, and photosynthesis-related pathways, enriching genes and transcription factors linked to antioxidant metabolism and photosynthesis. Metabolomic analyses showed that ColdSe1 positively influenced amino acid glucose metabolism, glycerolipid metabolism, hormonal pathways, and alanine/glutamate pathways under cold stress, while also upregulating metabolites associated with plant secondary metabolites (e.g., flavonoids, phenolic compounds) and antioxidant metabolism (e.g., α-linolenic acid metabolism). In contrast, high selenium concentrations (ColdSe2) disrupted phenylpropanoid biosynthesis, α-linolenic acid metabolism, and ABC transporter function, exacerbating cold-stress injury. This study highlights the critical role of Se in mitigating cold stress in rice, offering a theoretical basis for its application as an agricultural stress reliever. Full article

The tea tree root system is an important tissue for nutrient uptake, accumulation, and transport, and pH is an important environmental factor regulating the growth of tea tree (Camellia sinensis). However, the physiological and molecular mechanisms of how the tea tree root system responds to pH are unclear. In this study, Tieguanyin tea tree was used as the research object, and treated with different pH values to determine the morphological indexes of the tea plant root system and systematically study the physiological and molecular mechanisms of the effect of pH on the growth of the tea plant root system using transcriptomics in combination with metabolomics. The results showed that total root length, root surface area, root volume, total root tips, root fork number, and root crossing number of root crosses of the tea plant root system increased significantly (p < 0.05) with increasing pH. Transcriptome analysis showed that a total of 2654 characteristic genes were obtained in response to pH regulation in the root system of the tea plant, which were mainly enriched in six metabolic pathways. Metabolomics analysis showed that the metabolites with the highest contribution in differentiating tea plant responses to different pH regulations were mainly heterocyclic compounds, amino acids and derivatives, alkaloids, and flavonoids. Interaction network analysis showed that pH positively regulated the metabolic intensity of the MAPK signaling pathway (plant, plant hormone signal transduction, and RNA degradation pathway), positively regulated the content of the heterocyclic compound, amino acids and derivatives, and alkaloids, and positively regulated tea plant root growth. However, it negatively regulated ribosome, protein processing in the endoplasmic reticulum, and phenylpropanoid biosynthesis pathway intensity, and negatively regulated the flavonoid content. This study reveals the physiological and molecular mechanisms of the tea plant root system in response to pH changes and provides an important theoretical basis for the cultivation and management of tea plants in acidified tea plantations. Full article

Dendrobium officinale is a traditional and valuable medicinal herb, with extensive research conducted on its polysaccharides, alkaloids, and other components, yet studies on anthocyanins remain limited. In this study, we analyzed the expression levels of GST family genes in green and purplish D. officinale and found that DoGSTF11 is highly expressed in the purplish variety. DoGSTF11 is localized to the nucleus and cell membrane but lacks transcriptional activation activity. Overexpression of DoGSTF11 in tomato enhances anthocyanin accumulation, suggesting a role in anthocyanin sequestration or transport. Yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays further revealed that DoGSTF11 interacts with DoGST31, while DoIDD12 and DoNF-YB3 are potential transcriptional regulators based on promoter-binding assays and expression correlation. In conclusion, our study demonstrates that DoGST11 positively regulates anthocyanin accumulation in D. officinale. These findings provide valuable insights into the metabolic engineering of flavonoids in D. officinale. Full article

Storage conditions significantly impact the quality and functional properties of extra-virgin olive oil (EVOO). This study investigated the impact of light and dark storage on the nutritional quality of Umbrian EVOO and its effectiveness in tissue repair. The research aimed to simulate real-world conditions occurring during transport, retail, and domestic storage. Light exposure accelerated EVOO oxidation, significantly affecting peroxide levels (ranging from 5.19 to 24.30 meq O₂/kg of oil), total antioxidant capacity (measured spectrophotometrically, collectively ranging from 399.47 to 684.63 mg TE/kg of oil), and phenolic compound concentrations, particularly secoiridoids, lignans, and flavonoids (measured by HPLC, collectively ranging from 41.92 to 169.74 mg/kg of oil). Statistically significant differences (p < 0.01) were recorded between the control sample and the others in almost all cases, after storage. For instance, both light and dark exposure over a 24-month period resulted in a marked reduction (p < 0.01) in oleocanthal, pinoresinol, luteolin, and apigenin. Pigment levels were also affected, representing a rapid and cost-effective indicator of product oxidative degradation. The loss of phenolic compounds (especially oleacein and oleocanthal, which showed the most significant reductions of approximately 75% and 60%, respectively), impaired the EVOO’s wound-healing properties, affecting key tissue regeneration processes such as keratinocyte migration, hyaluronic acid synthesis, and angiogenesis. Notably, oleocanthal and oleacein, present at higher concentrations in fresh extracts, emerged as the primary contributors to the observed dermal effects and wound-healing processes, demonstrating a significant highest efficacy (p < 0.0001) in promoting wound closure. These findings underscore the critical role of EVOO storage in preserving its sensory properties and labile components with tissue repair and regeneration functions. Full article

Background: Systemic arterial hypertension is one of the leading global health concerns, significantly increasing the risk of cardiovascular and kidney diseases, including nephrolithiasis. The treatment, still far from ideal, is constantly undergoing new alternatives. In this context, medicinal plants rich in flavonoids, such as naringenin—a compound found in citrus fruits—have gained attention for their potential diuretic, nephroprotective, and blood pressure-lowering effects. Objectives: This study aimed to evaluate the effects of naringenin (100 mg/kg, orally) over nine days on blood pressure, renal function, and calcium oxalate crystal formation in normotensive Wistar (NTR) and spontaneously hypertensive male rats (SHR). Methods: Key assessments included blood pressure and heart rate measurements in vivo, urine volume and electrolyte excretion in vivo, in vitro calcium oxalate crystallization, and in silico molecular docking analyses to investigate molecular interactions. Results: Naringenin treatment significantly reduced blood pressure and increased diuresis in both NTR and SHR groups, while a notable natriuretic effect was observed specifically in NTR. In vitro, naringenin reduced the formation of calcium oxalate crystals in urines from NTR. Molecular docking studies suggested that these effects may be mediated by interactions with SGLT1 and SGLT2 transporters, potentially explaining the diuretic and natriuretic outcomes. Additionally, interactions with MMP-9 and β2-adrenergic receptors may contribute to the reduction in crystal formation. Conclusions: Collectively, these findings indicate that repeated administration of naringenin exerts beneficial effects on both cardiovascular and renal parameters, and point to promising molecular targets that may underlie its protective actions. Full article

Background: This study evaluated the polyphenolic composition, antibacterial activity, molecular docking interactions, and pharmacokinetic properties of Romanian oak and fir honeydew honeys. Methods: Spectrophotometric methods quantified total phenolic, flavonoid contents and antioxidant activity, and individual polyphenols were identified via HPLC-MS. Antibacterial efficacy against Gram-positive and Gram-negative bacteria was evaluated by determining the bacterial inhibition percentage and minimum inhibitory concentrations. The bioactive compounds identified via LC-MS analysis were used to further delineate the possible antibacterial activities in silico. Molecular docking was carried out to predict the binding interactions and complex formation of the identified compounds against protein crystal structures of the bacteria used in this study. Additionally, the pharmacokinetic profile of compounds with high inhibitory potential was assessed via ADMET (absorption, Distribution, Metabolism, Excretion, toxicity) predictors to ascertain their value. Results: Fir honeydew honey showed higher total phenolic (844.5 mg GAE/kg) and flavonoid contents (489.01 mg QUE/kg) compared to oak honeydew honey, correlating with more potent antioxidant activity (IC50 = 5.16 mg/mL). In vitro antimicrobial tests indicated a stronger inhibitory effect of fir honeydew honey, especially against Gram-positive strains like S. aureus, S. pyogenes, and L. monocytogenes, alongside certain Gram-negative strains such as E. coli and H. influenzae. Oak honeydew honey displayed selective antimicrobial action, particularly against P. aeruginosa and S. typhimurium. The docking outcomes showed rutin, rosmarinic acid, beta resorcylic acid, quercetin, ferulic acid, and p-coumaric acid have high inhibitory activities characterised by binding affinities and binding interactions against shiga toxin, riboflavin synthase, ATP-binding sugar transporter-like protein, undecaprenyl diphosphate synthase, putative lipoprotein, sortase A, and immunity protein, making them key contributors to the honey’s antimicrobial activity. Moreover, beta-resorcylic acid, quercetin, ferulic acid, and p-coumaric acid revealed interesting ADMET scores that qualify honey to serve as a good antimicrobial agent. Conclusions: These findings support their potential use as natural antibacterial agents and emphasise the value of integrating chemical, biological, and computational approaches for multidisciplinary characterisations. Full article

Salt stress poses a significant threat to crop growth. While brassinolide (BR) has been shown to alleviate its adverse effects and modulate plant development, the precise mechanism underlying BR-induced salt tolerance in rice remains unclear. In this study, the Chaoyouqianhao and Huanghuazhan rice varieties were employed to investigate the effects of BR seed soaking on the seedling phenotype, physiology, transcriptome, and metabolome under salt stress. The results demonstrated that BR treatment significantly enhanced rice plant height, root length, biomass, and antioxidant enzyme activities, while reducing leaf membrane damage, promoting ion homeostasis, and improving the photosynthetic capacity and salt tolerance. The transcriptome analysis revealed that BR regulated the expression of 1042 and 826 genes linked to antioxidant activity, ion homeostasis, photosynthesis, and lipid metabolism under salt stress. These included genes involved in Na⁺ efflux (OsNCED2, OsHKT2;1, and OsHKT1;1), photosynthetic electron transport (OsFd5 and OsFdC1), photosystem II (OsPsbR1, OsPsbR2, and OsPsbP), and CO₂ fixation. The metabolomic analysis identified 91 and 57 metabolite alterations induced by BR, primarily linked to amino acid, flavonoid, and lipid metabolism, with notable increases in antioxidant metabolites such as lignanoside, isorhamnetin, and L-glutamic acid. The integrated analysis highlighted the pivotal roles of 12-OPDA in α-linolenic acid metabolism and genes related to lipid metabolism, JA metabolism, and JA signal transduction in BR-mediated salt tolerance. Full article

Aluminum toxicity severely inhibits root elongation and nutrient uptake, causing global agricultural yield losses. Dissolved Al³⁺ are accumulating in plants and subsequently entering food chains via crops and forage plants. Chronic dietary exposure to Al³⁺ poses a risk to human health. In this study, Pseudomonas sp. strain ADAl3–4, isolated from plant rhizosphere soil, significantly enhanced plant development and biomass. Phenotypic validation using Arabidopsis mutants showed that strain ADAl3–4 regulates plant growth and development under aluminum stress by reprogramming the cell cycle, regulating auxin and ion homeostasis, and enhancing the root absorption of Al³⁺ from the soil. Transcriptomic and biochemical analyses showed that strain ADAl3–4 promotes plant growth via regulating signal transduction, phytohormone biosynthesis, flavonoid biosynthesis, and antioxidant capacity, etc., under aluminum stress. Our findings indicate that Pseudomonas sp. strain ADAl3–4 enhances plant development and stress resilience under Al³⁺ toxicity through a coordinated multi-dimensional regulatory network. Furthermore, strain ADAl3–4 promoted the root absorption of aluminum rather than the transportation of Al to the aerial part, endowing it with application prospects. Full article

In order to achieve differentiated utilization of red raspberry fruit pulp, a widely targeted metabolomics analysis of pulp from two regions was performed to explore the effect of plateau environment on the accumulation of secondary metabolites of red raspberry. Ultra-high performance liquid chromatography–mass spectrometry (UHPLC-MS/MS), combined with principal component analysis and Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA), was used to process the data and correlate them with the results of four antioxidant assays. Fourteen metabolites were characterized in the fruit pulp of Qinghai raspberries, and 618 up-regulated differential metabolites were found, which was 4.35 times higher than that of Yunnan. Flavonoids and phenolic acids were more abundant, with kaempferol-3-O-sambubioside being endemic to Qinghai, and saccharin-7-O-glucoside and rhamnocereus citrinus being endemic to Yunnan. Metabolic pathway enrichment analysis showed that the fruit pulp from the two regions differed significantly (p < 0.01) in ATP-binding cassette transporter (ABC transporter), purine metabolism, and so on. Antioxidant analysis showed that the Yunnan raspberries (Y-RP) were significantly superior to Qinghai raspberries (Q-RP) in terms of DPPH radical scavenging ability (DPPH) and ferric ion reducing/antioxidant power (FRAP), while Q-RP was significantly superior to Y-RP in terms of oxygen radical absorbance capacity (ORAC) and ABTS radical scavenging capacity (ABTS). This study showed that the plateau environment significantly promotes the accumulation of functional secondary metabolites of red raspberry, which provides a theoretical basis for the development of the functional components of plateau raspberry. Full article