In vitro inhibitory effects of polyphenols from Tartary buckwheat on xanthine oxidase: Identification, inhibitory activity, and action mechanism

Pathology, target discovery, and the evolution of XO inhibitors from the first discovery to recent advances (2020-2023)

Hyperuricemia, a disease characterized by elevation of serum uric acid level beyond 6 mg/dL. This elevation led to appearance of symptoms from joint pain to gout and from gout to difficulty in mobility of the patient. So, in this review, we have summarized the pathology of hyperuricemia, discovery of target and discovery of first XO inhibitor. At last, this review provides in-sights about the recently discovered as natural XO inhibitors, followed by design, structure activity relationship and biological activity of synthetic compounds as XO inhibitors discovered between 2020 and 2023 years. At last, the pharmacophores generated in this study will guide new researchers to design and modify the structure of novel XO inhibitors.

Ferulic acid ameliorates hyperuricemia by regulating xanthine oxidase

Hyperuricemia is characterized by elevated uric acid (UA) level in the body. The xanthine oxidase (XO) inhibitory ability is an important way to evaluate the anti-hyperuricemia effect of natural products. Ferulic acid (FA) is a phenolic acid compound, and it is a free radical scavenger with many physiological functions. The aim of this study was to investigate the structure-activity relationship, potential mechanism and interaction of FA as XO's inhibitor. In the cell experiment, using 1.25 mM adenosine to incubate for 24 h under the optimal conditions (37 °C, pH = 7.2) can increase the UA production by 1.34 folds. PCR analysis showed that FA could reduce the mRNA expression level of XO. FA inhibited XO in a mixed mode (IC50 = 13.25 μM). The fluorescence quenching of XO by FA occurs through a static mechanism, with an inhibition constant of Ki = 9.527 × 10-5 mol L-1 and an apparent coefficient of α = 1.768. The enthalpy and entropy changes were found as -267.79 KJ mol-1 and - 860.85 KJ mol-1, indicating that both hydrogen binding and hydrophobic are involved in the interaction of this polyphenolic natural compound with XO. Thus, FA supplementation may be a potential therapeutic strategy to improve hyperuricemia by reducing UA production.

Effects of extracted oil of fermented Tartary buckwheat on lipid-lowering, inflammation modulation, and gut microbial regulation in mice

This study investigated the composition of Tartary buckwheat oil fermented by Monascus purpureus and extracted under supercritical CO2 conditions (FTBO) and evaluated its effects on lipid-lowering, inflammation modulation, and gut microbial regulation in mice that were fed a high-fat diet (MOD). Compared with the raw oil (TBO), the γ-oryzanol content reached 27.09 mg g-1; the monounsaturated fatty acid (MUFA) content (such as oleic acid and palmitic acid) was elevated; and the antioxidant capacities of DPPH, ABTS, and hydroxyl were improved in FTBO (p < 0.0001). Then, supplementation with FTBO had a remarkable effect on reducing the body weight and visceral obesity as well as alleviating hyperglycemia, dyslipidemia, inflammatory reactions, and liver damage. The TC, TG, and LDL-C levels in the liver and plasma were reduced, and the HDL-C levels in the liver were increased (p < 0.05). In particular, the high-dose group (FTBOH) exhibited the most significant effect on reducing the pro-inflammatory cytokines ET, TNF-α, IL-1β, and IL-6 in the liver, which were 18.85, 570.12, 50.47, and 26.22 pg mL-1, respectively (p < 0.05). Moreover, FTBO reversed intestinal disorders and increased the intestinal microbial diversity and richness. The relative abundance of beneficial bacteria, such as Bifidobacterium, Lactobacillus, Limosilactobacillus, and Lachnospiraceae_UCG-006, were increased, and the relative abundance of the harmful bacteria Staphylococcus and Lachnoclostridium were reduced. In summary, FTBO has potential applications as a dietary supplement or dietary modifier in lowering blood lipids, modulating immune activity, and reversing intestinal disorders. This study provides reference guidance for the subsequent industrialization and development of Tartary buckwheat, the extension of the industrial chain, the development of new products, and the extraction of functional components.

Polyphenol Composition, Antioxidant Capacity and Xanthine Oxidase Inhibition Mechanism of Furong Plum Fruits at Different Maturity Stages

An experiment was conducted on the polyphenol content, flavonoid content, anthocyanin content, and antioxidant capacity of Furong plum (Prunus salicina Lindl. cv. "furong") at different maturity stages to determine the most suitable maturity stage. The inhibition of plum polyphenols on xanthine oxidase (XOD) was measured, and its kinetics were studied to reveal the inhibitory mechanism. The experimental results showed that the polyphenol, flavonoid and anthocyanin contents of plums at the ripe stage were the highest, reaching 320.46 mg GAE/100 g FW, 204.21 mg/100 g FW, and 66.24 mg/100 g FW, respectively, in comparison those of the plums at the immature and mid-ripe stages. The antioxidant capacity of the ripe plums was stronger than it was during the other stages of the plums growth. Among them, the total polyphenols of the ripe plums exhibited the strongest antioxidant capacity (IC50 values against DPPH and hydroxyl radicals were 28.19 ± 0.67 μg/mL and 198.16 ± 7.55 μg/mL, respectively), which was between the antioxidant capacity of the free polyphenols and bound polyphenols. The major phenolic monomer compounds of plum polyphenols were flavan-3-ols (epicatechin, catechin, proanthocyanidin, and procyanidin B2), flavonols (myricetin), and phenolic acids (chlorogenic acid, ferulic acid, and protocatechuic acid). Additionally, plum polyphenols exhibited a strong inhibitory effect on XOD, with an IC50 value of 77.64 μg/mL. The inhibition kinetics showed that plum polyphenols are mixed-type inhibitors that inhibit XOD activity and that the inhibition process is reversible. The calculated values of Ki and α were 16.53 mmol/L and 0.26, respectively.

Research progress on the prevention and treatment of hyperuricemia by medicinal and edible plants and its bioactive components

Hyperuricemia is another common metabolic disease, which is considered to be closely related to the development of many chronic diseases, in addition to the "three highs." Currently, although drugs show positive therapeutic effects, they have been shown to produce side effects that can damage the body. There is growing evidence that medicinal and edible plants and their bioactive components have a significant effect on hyperuricemia. In this paper, we review common medicinal and edible plants with uric acid-lowering effects and summarize the uric acid-lowering mechanisms of different bioactive components. Specifically, the bioactive components are divided into five categories: flavonoids, phenolic acids, alkaloids, polysaccharides, and saponins. These active substances exhibit positive uric acid-lowering effects by inhibiting uric acid production, promoting uric acid excretion, and improving inflammation. Overall, this review examines the potential role of medicinal and edible plants and their bioactive components as a means of combating hyperuricemia, with the hope of providing some reference value for the treatment of hyperuricemia.

Studies on the interaction mechanism between xanthine oxidase and osmundacetone: Molecular docking, multi-spectroscopy and dynamical simulation

Xanthine oxidase (XO) is a key enzyme in uric acid production, and its molybdopterin (Mo-Pt) domain is an important catalytic center when xanthine and hypoxanthine are oxidated. It is found that the extract of Inonotus obliquus has an inhibitory effect on XO. In this study, five key chemical compounds were initially identified using liquid chromatography-mass spectrometry (LC-MS), and two compounds, osmundacetone ((3E)-4-(3,4-dihydroxyphenyl)-3-buten-2-one) and protocatechuic aldehyde (3,4-dihydroxybenzaldehyde), were screened as the XO inhibitors by ultrafiltration technology. Osmundacetone bound XO strongly and competitively inhibited XO with a half-maximal inhibitory concentration of 129.08 ± 1.71 μM, and its inhibition mechanism, was investigated. Osmundacetone and XO via static quenching and spontaneously bound with XO with high affinity, primarily via hydrophobic interactions and hydrogen bonds. Molecular docking studies showed that osmundacetone was inserted into the Mo-Pt center and interacted with hydrophobic residues of Phe911, Gly913, Phe914, Ser1008, Phe1009, Thr1010, Val1011, and Ala1079 of XO. In summary, these findings suggest that provide theoretical basis for the research and development of XO inhibitors from Inonotus obliquus.

Beneficial effects of phenolic compounds: native phenolic compounds vs metabolites and catabolites

In the human body, the positive effects of phenolic compounds are increasingly observed through their presence in tissues and organs in their native form or in the form of metabolites or catabolites formed during digestion, microbial metabolism, and host biotransformation. The full extent of these effects is still unclear. The aim of this paper is to review the current knowledge of beneficial effects of native phenolic compounds or their metabolites and catabolites focusing on their role in the health of the digestive system, including disorders of the gastrointestinal and urinary tracts and liver. Studies are mostly connecting beneficial effects in the gastrointestinal and urinary tract to the whole food rich in phenolics, or to the amount of phenolic compounds/antioxidants in food. Indeed, the bioactivity of parent phenolic compounds should not be ignored due to their presence in the digestive tract, and the impact on the gut microbiota. However, the influence of their metabolites and catabolites might be more important for the liver and urinary tract. Distinguishing between the effects of parent phenolics vs metabolites and catabolites at the site of action are important for novel areas of food industry, nutrition and medicine.

New Insights into the Inhibition of Hesperetin on Polyphenol Oxidase: Inhibitory Kinetics, Binding Characteristics, Conformational Change and Computational Simulation

The inhibitory activity of hesperetin on polyphenol oxidase (PPO) and their interaction characteristics were investigated using multiple spectroscopic methods and computational simulation. Hesperetin, a mixed inhibitor, reversibly inhibited PPO activity, and its half-maximum inhibitory concentration (IC₅₀) values on monophenolase and diphenolase were 80.8 ± 1.4 μM and 776.0 ± 15.5 μM, respectively. Multivariate curve resolution-alternate least squares (MCR-ALS) analysis suggested PPO interacted with hesperetin and formed PPO-hesperetin complex. Hesperetin statically quenched PPO's endogenous fluorescence, and hydrophobic interactions mainly drove their binding. Hesperetin affected the polarity of the microenvironment around the Trp residues in PPO, but had no effect on that around Tyr residues. Circular dichroism (CD) results showed that hesperetin increased α-helix content and decreased β-fold and random coil contents, thus tightening PPO's structure. Molecular docking showed that hesperetin entered the hydrophobic cavity of PPO, bound near the dinuclear copper active center, interacted with Val283, Phe264, His85, Asn260, Val248, and His263 via hydrophobic interactions, formed hydrogen bonds with Met280, His89, and His259 residues and also interacted with Phe292, His61, Phe90, Glu256, His244, Asn260, Phe264, and Gly281 via van der Waals forces. The molecular dynamics simulation results also demonstrated that the addition of hesperetin reduced the stability and hydrophobicity of PPO and increased PPO's structural denseness. Thus, the inhibition of hesperetin on PPO may be because hesperetin bound near the active center of PPO, interacted with the surrounding residues, occupied the binding site for substrate, and induced the changes in PPO's secondary structure, thus inhibiting the catalytic activity of PPO. This study may provide novel views for the inhibition of hesperetin on PPO and theoretical guidance for developing flavonoids as new and efficient PPO inhibitors.

In Vitro Inhibitory Effects of Polyphenols from Flos sophorae immaturus on α-Glucosidase: Action Mechanism, Isothermal Titration Calorimetry and Molecular Docking Analysis

Flos sophorae immaturus (FSI) is considered to be a natural hypoglycemic product with the potential for a-glucosidase inhibitory activity. In this work, the polyphenols with α-glucosidase inhibition in FSI were identified, and then their potential mechanisms were investigated by omission assay, interaction, type of inhibition, fluorescence spectroscopy, circular dichroism, isothermal titration calorimetry and molecular docking analysis. The results showed that five polyphenols, namely rutin, quercetin, hyperoside, quercitrin and kaempferol, were identified as a-glucosidase inhibitors with IC₅₀ values of 57, 0.21, 12.77, 25.37 and 0.55 mg/mL, respectively. Quercetin plays a considerable a-glucosidase inhibition role in FSI. Furthermore, the combination of quercetin with kaempferol generated a subadditive effect, and the combination of quercetin with rutin, hyperoside and quercitrin exhibited an interference effect. The results of inhibition kinetics, fluorescence spectroscopy, isothermal titration calorimetry and molecular docking analysis showed that the five polyphenols were mixed inhibitors and significantly burst the fluorescence intensity of α-glucosidase. Moreover, the isothermal titration calorimetry and molecular docking analysis showed that the binding to α-glucosidase was a spontaneous heat-trapping process, with hydrophobic interactions and hydrogen bonding being the key drivers. In general, rutin, quercetin, hyperoside, quercitrin and kaempferol in FSI are potential α-glucosidase inhibitors.

Elucidating the toxicity mechanism of AFM2 and the protective role of quercetin in albino mice

Aflatoxin M2 (AFM2) is a type of mycotoxin detected in milk or dairy products from animals consuming contaminated feed. In this study, the toxicity mechanism of AFM2 and the protective effects of quercetin were investigated in albino mice. For this purpose, the mice were divided into 6 groups and the groups were fed with quercetin and AFM2. The toxic effects of AFM2 and the protective properties of quercetin were investigated using physiological, biochemical and cytogenetic parameters. The genotoxic mechanism of AFM2 and the protective role of quercetin were investigated by molecular docking, which is an in silico model. As a result, 16 mg/kg b.w AFM2 administration caused serious changes in body weight, organ index, kidney and liver weight, and deterioration of antioxidant/oxidant balance in liver and kidney organs. The decrease in glutathione levels along with an increase in malondialdehyde (MDA) levels in the liver and kidney after AFM2 administration indicates that oxidative stress is induced. The increases in alanine transaminase (ALT) and aspartat transaminase (AST) levels, which are indicators of liver damage, and the increases in serum levels of blood urea nitrogen (BUN) and creatinine, which are indicators of kidney damage, confirm the damage in both organs. AFM2 also caused genotoxicity by inducing micronucleus (MN) and chromosomal abnormalities (CAs) in bone marrow tissue. It has been determined that AFM2, which exhibits genotoxicity as a result of its clastogenic and aneugenic effects, causes CAs by interacting with DNA. Quercetin provided significant protection by improving liver and kidney tissues, partial normalization in serum parameter levels, and severe reductions in MN and CAs. The highest protection was determined as 74.1% against dicentric chromosome formations in 50 mg/kg b.w quercetin application. The interaction of quercetin with xanthine oxidase and nitric oxide synthase enzymes was determined in silico with an inhibition constant in the range of 283.71-476.17 nM. These interactions cause changes in the activity of enzymes, reducing the oxidative load in the cell, and in this way, quercetin provides protection. All toxic effects induced by AFM2 were decreased with quercetin administration dose-dependently, and this protective effect was associated with quercetin's reduction of oxidative load by inhibiting the free radical-producing enzyme. All toxic effects caused by AFM2 were decreased with quercetin administration in a dose-dependent manner, and this protective effect was associated with quercetin's reduction of oxidative load by inhibiting the enzyme that produces free radicals.

Screening of Monoamine Oxidase B Inhibitors from Fragaria nubicola by Ligand Fishing and Their Neuroprotective Effects

Fragaria nubicola, known as Tibetan strawberry, is an edible plant possessing various health-promoting effects. However, its functional compositions were rarely studied. In this work, monoamine oxidase B (MAO-B) inhibitors in this plant were rapidly screened using the enzyme-functionalized magnetic nanoparticles coupled with UPLC-QTOF-MS. Two inhibitors, quercetin-3-O-β-d-glucuronide-6″-methyl ester (1) and kaempferol-3-O-β-d-glucuronide-6″-methyl ester (2), were identified from this plant with the IC₅₀ values of 19.44 ± 1.17 and 22.63 ± 1.78 μM, respectively. Enzyme kinetic analysis and molecular docking were carried out to investigate the mechanism of inhibition. Contents of both compounds as well as those of total phenolics and flavonoids were quantified to be 24.76 ± 1.26, 35.59 ± 1.17, 837.67 ± 10.62, and 593.46 ± 10.37 μg/g, respectively. In addition, both compounds exhibited significant neuroprotective effects on 6-hydroxydopamine-induced PC12 cells. This is the first report on the neuroprotective components of F. nubicola, suggesting its potential for developing neuroprotective functional food.

An Insight into Diverse Activities and Targets of Flavonoids

BACKGROUND

Flavonoids belong to the chemical class of polyphenols and are in the category of secondary metabolites imparting a wide protective effect against acute and chronic diseases.

OBJECTIVE

The study aims to investigate and summarize the information of various flavonoids extracted, isolated from various sources, and possess different pharmacological properties by acting on multiple targets.

METHODS

This comprehensive review summarizes the research information related to flavonoids and their pharmacological action targets from various sources like PubMed, Google Scholar and Google websites.

RESULTS

Extracted information in the paper discusses various therapeutic effects of flavonoids isolated from medicinal plant sources, which have the property to inhibit several enzymes, which finally results in health benefits like anti-cancer, anti-bacterial, antioxidant, anti-allergic, and anti-viral effects. This study also showed the different solvents and methods involved in the extraction and characterization of the isolated phytochemical constituents.

CONCLUSION

The findings showed the contribution of several flavonoids in the management and inhibition of various acute and chronic sicknesses by acting on different sites in the body. This study may lead to gaining interest for more research on the bioactives of different medicinal plants for the discovery of new lead compounds or further improvement of the efficacy of the existing compound.

Nutritional Attributes and Phenolic Composition of Flower and Bud of Sophora japonica L. and Robinia pseudoacacia L

Sophora japonica L. (SJL) and Robinia pseudoacacia L. (RPL) are widely cultivated in China. However, the utilization of their main by-products are limited due to a lack of comprehensive nutritional attributes. Herein, the proximate composition, mineral elements, fatty acids, amino acids, monosaccharides, and phenolics were analyzed to investigate the nutritional attributes of SJL and RPL. Dietary fiber was the main ingredient in SJL and RPL, followed by protein and lipids. The content of Fe in SJL and RPL was highest, especially in flowers of SJL, reaching about 1179.51 mg/kg. The total unsaturated fatty acids accounted for 89.67% of the bud of SJL. Meanwhile, the essential amino acids contents of the flower and bud of SJL and RPL accounted for 35.95-40.59% of total amino acids. The flower of SJL (373.75 mg/g) exhibited the most abundant monosaccharides. Meanwhile, the total phenolics and flavonoid contents in the buds of SJL and RPL were significantly higher than that of the flower, implying the buds possessed better biological activity. Moreover, the bud of SJL possessed the most abundant phenolics. The results provided a reference for the development of functional food derived from SJL and RPL.

Metabolomic and transcriptomic exploration of the uric acid-reducing flavonoids biosynthetic pathways in the fruit of Actinidia arguta Sieb. Zucc

Flavonoids from Actinidia arguta Sieb. Zucc. can reduce uric acid in mice. However, the molecular basis of its biosynthesis is still unclear. In this paper, we used a combination of extensively targeted metabolomics and transcriptomics analysis to determine the types and differences of flavonoids in the fruit ripening period (August to September) of two main cultivated varieties in northern China. The ethanol extract was prepared, and the potential flavonoids of Chrysin (Flavone1), Rutin (Flavone2), and Daidzein (Flavone3) in Actinidia arguta Sieb. Zucc. were separated and purified by HPD600 macroporous adsorption resin and preparative liquid chromatography. The structure was identified by MS-HPLC, and the serum uric acid index of male Kunming mice was determined by an animal model test.125 flavonoids and 50 differentially regulated genes were identified. The contents of UA (uric acid), BUN (urea nitrogen), Cr (creatinine), and GAPDH in mouse serum and mouse liver glycogen decreased or increased in varying degrees. This paper reveals the biosynthetic pathway of uric acid-reducing flavonoids in the fruit of Actinidia arguta Sieb. Zucc., a major cultivar in northern China, provides valuable information for the development of food and drug homologous functional foods.

Anti-Inflammatory and Hypouricemic Effect of Bioactive Compounds: Molecular Evidence and Potential Application in the Management of Gout

Gout is caused by the deposition of monosodium urate crystals in the joint and represents the most common form of inflammatory arthritis in men. Its prevalence is rising worldwide mainly due to the increase of risk factors associated with the disease, in particular hyperuricemia. Besides gout, hyperuricemia leads to an increased inflammatory state of the body with consequent increased risk of comorbidities such as cardiovascular diseases. Increasing evidence shows that bioactive compounds have a significant role in fighting inflammatory and immune chronic conditions. In gout and hyperuricemia, these molecules can exert their effects at two levels. They can either decrease serum uric acid concentrations or fight inflammation associated with monosodium urate crystals deposits and hyperuricemia. In this view, they might be considered valuable support to the pharmacological therapy and prevention of the disease. This review aims to provide an overview of the beneficial role of bioactive compounds in hyperuricemia, gout development, and inflammatory pathways of the disease.

The inhibitory kinetics and mechanism of quercetin-3-O-rhamnoside and chlorogenic acid derived from Smilax china L. EtOAc fraction on xanthine oxidase

Smilax china L. showed various biological activities mainly due to its phenolic components; however, the mechanism of isolated phenolic fraction against xanthine oxidase (XO) has not been investigated. Quercetin-3-O-rhamnoside (QORh) and chlorogenic acid (CGA) extracted from Smilax china L. ethyl acetate fraction was analyzed for its XO inhibitory kinetics and mechanism using multispectroscopic methods and molecular docking techniques. QORh and CGA reversibly inhibited XO activity in competitive and non-competitive modes, respectively. The bioactive compounds bound with XO were dominated mainly by hydrogen bonds and van der Waals forces to form QORh-XO, and CGA-XO complexes with one affinity binding site. The synchronous fluorescence, circular dichroism, three-dimensional (3D) fluorescence, and Fourier transform infrared spectra exhibited that XO binding with QORh or CGA leads to the secondary and tertiary structural variation of the protein. Additionally, molecular docking further revealed that QORh binds to the active site of XO and forms hydrogen coupling with amino acid residues. The results showed that QORh and CGA had inhibitory activity on XO, which might be further used to modify the bioactive compounds and improve their efficacy to treat gout.

Hypouricemic effect of 2,4-dihydroxybenzoic acid methyl ester in hyperuricemic mice through inhibiting XOD and down-regulating URAT1

In this paper, we reported the hypouricemic effect of 2,4-dihydroxybenzoic acid methyl ester (DAE), a component of Ganoderma applanatum, in hyperuricemic mice through inhibiting XOD and down-regulating URAT1. Computationally, DAE showed a high similarity to allopurinol and depicted a high affinity in docking to XOD. In vitro, DAE exhibited an inhibitory effect against XOD. Importantly, DAE demonstrated a remarkable hypouricemic effect, decreasing serum uric acids (SUAs) of hyperuricemic mice (407 ± 31 μmol/L) to 195 ± 23, 145 ± 33 and 134 ± 16 μmol/L (P < 0.01) at the doses of 20, 40, and 80 mg/kg with a dose-dependent manner and showing efficacies at 54-68 %, which were close to the efficacies of allopurinol (61 %) and benzbromarone (57 %). DAE depicted higher and negatively dose-independent urinary uric acids in comparison with that of the hyperuricemic control, implying DAE exerted an uricosuric effect and also a reduction effect on uric acid production. Unlike toxic allopurinol and benzbromarone, no general toxicity on body weights and no negative influence on liver, kidney, spleen and thymus were observed for DAE. Mechanistically, DAE inhibited XOD activities in vivo. Moreover, DAE up-regulated OAT1 and down-regulated GLUT9, URAT1 and CNT2. Overall, DAE may present a hypouricemic effect through inhibiting XOD and up-regulating OAT1 and down-regulating GLUT9, URAT1 and CNT2. This work provided novel insights into the hypouricemic effect of DAE and G. applanatum.

The Improvement of Sensory and Bioactive Properties of Yogurt with the Introduction of Tartary Buckwheat

The incorporation of cereals in yogurt has recently gained increasing consumer approval, for its high nutritional value and health benefits, all over the world. Following this emerging trend, Tartary buckwheat (TB) was supplemented into yogurt as a natural functional ingredient in order to develop a yogurt with enhanced product characteristics and consumer acceptability. The impact of TB addition on physicochemical properties (pH, acidity, apparent viscosity, etc.) and the viability of lactic acid bacteria in yogurt was investigated. It is found that the TB introduction can reduce the pH, increase the acidity and apparent viscosity, and also greatly boost the bioactivities of yogurt. Response surface analysis demonstrated that yogurt with 8 g of TB, 10 g of sugar, and a fermentation duration of 5 h had the highest overall acceptability, and these cultural conditions were chosen as the best. Furthermore, the TB-added yogurt had not only a better sensory and aroma profile, but also good prospective health advantages when compared to regular yogurt. Our research shows that adding TB to yogurt has a significant positive impact on both overall quality and sensory characteristics, making a compelling case for using TB yogurt and developing new fermented dairy products.

Comparison of Heat and Drought Stress Responses among Twelve Tartary Buckwheat (Fagopyrum tataricum) Varieties

The use of orphan crops could mitigate the effects of climate change and improve the quality of food security. We compared the effects of drought, high temperature, and their combination in 12 varieties of Tartary buckwheat (Fagopyrum tataricum). Plants were grown at 21/19 °C or 28/26 °C under well-watered and water-stressed conditions. Plants were more discriminated according to environmental conditions than variety, with the exception of Islek that was smaller and produced fewer leaves, inflorescences, and seeds than the other varieties. The combination of high temperature and water stress had a stronger negative impact than each stress applied separately. The temperature increase stimulated leaf and flower production while water stress decreased plant height. Leaf area decreased with both temperature and water stress. High temperature hastened the seed initiation but negatively affected seed development such that almost all seeds aborted at 28 °C. At 21 °C, water stress significantly decreased the seed production per plant. At the physiological level, water stress increased the chlorophyll content and temperature increased the transpiration rate under well-watered conditions. High temperature also increased the polyphenol and flavonoid concentrations, mainly in the inflorescences. Altogether, our results showed that water stress and temperature increase in particular negatively affected seed production in F. tataricum.