A comprehensive review of flaxseed (Linum usitatissimum L.): health-affecting compounds, mechanism of toxicity, detoxification, anticancer and potential risk

Efficient CO2 adsorption by deoiled flaxseed hydrochar

This study optimizes CO2 adsorption using hydrochar from de-oiled flaxseed (FDOP), a waste byproduct of the oil extraction industry, through hydrothermal carbonization (HTC). The aim is to enhance CO2 capture sustainably and cost-effectively. Using Response Surface Methodology (RSM), in optimal conditions achieved 1153.26 mg/g CO2 adsorption capacity under 215.15 °C synthesis temperature, 3.05 h synthesis time, 0.99 M acid concentration, 8.997 bar pressure, and 25.07 °C adsorption temperature. Statistical analysis (F-value: 44.48, R²: 0.9705) confirmed strong model reliability. Kinetic analysis showed both physical and chemical adsorption, while thermodynamic analysis revealed exothermic behavior (ΔH° values: -46.697 kJ/mol for M-225, -40.230 kJ/mol for MA-203). After 10 regeneration cycles, the adsorption capacity was reduced by only 2.8% and 3.1%, indicating excellent recyclability. This study highlights FDOP-derived hydrochar as a highly efficient, low-cost adsorbent, offering industrial applications for carbon capture and waste management.

Cyanide content, nutrient composition, physicochemical properties and sensory quality of flaxseed oil bodies prepared from flaxseeds (Linum usitatissimum L.) treated with different heat treatment methods

Flaxseeds (Linum usitatissimum L.) were pre-treated with different heat treatment methods including steaming (100 °C for 10 min, 20 min or 30 min), roasting (120 °C for 10 min, 20 min or 30 min) and microwave (560 W for 1 min, 2 min or 3 min). Flaxseed oil bodies were prepared from the flaxseeds with and without heat treatment, and the cyanide content, yield rate, nutritional composition, physico properties, rheological behavior, and sensory characteristic were evaluated. These three types of heat treatment methods could effectively reduce the content (1.87-13.98 mg/kg) of toxic cyanide in flaxseed oil bodies. In addition, compared with the flaxseed oil bodies in steaming and roasting treated groups, the flaxseed oil bodies in microwave treated group exhibited higher yield rate (36.37-39.71 %), lower level of lipid oxidation (peroxide value, 6.10-7.10 mmol/kg lipid; thiobarbituric acid reactive substances, 1.99-2.20 mg MDA/kg lipid), higher content of polyunsaturated fatty acids (PUFAs, 63.33-64.22 %), better viscoelasticity, and better appearance color. Therefore, microwave treatment at 560 W with less than 3 min is a suitable preheating method of flaxseeds, thus improving the quality of the obtaind oil bodies.

Unveiling the Power of Flax Lignans: From Plant Biosynthesis to Human Health Benefits

BACKGROUND

Flax (Linum usitatissimum L.) is the richest plant source of lignin secondary metabolites. Lignans from flax have been applied in the fields of food, medicine, and health due to their significant physiological activities. The most abundant lignan is secoisolariciresinol, which exists in a glycosylated form in plants.

RESULTS

After ingestion, it is converted by human intestinal flora into enterodiol and enterolactone, which both have physiological roles. Here, the basic structures, contents, synthesis, regulatory, and metabolic pathways, as well as extraction and isolation methods, of flax lignans were reviewed. Additionally, the physiological activity-related mechanisms and their impacts on human health, from the biosynthesis of lignans in plants to the physiological activity effects observed in animal metabolites, were examined.

CONCLUSIONS

The review elucidates that lignans, as phenolic compounds, not only function as active substances in plants but also offer significant nutritional values and health benefits when flax is consumed.

Flaxseed Lowers Blood Pressure in Hypertensive Subjects: A Meta-Analysis of Randomized Controlled Trials

This systematic review and meta-analysis study aimed to evaluate the effectiveness of flaxseed supplementation on blood pressure (BP) in patients with hypertension based on the data from randomized clinical trials (RCTs). Three databases (PubMed [MEDLINE], Scopus, and ISI Web of Science) were searched from inception up to August 10, 2024. Relevant studies meeting our eligibility criteria were obtained. A random-effects model was used to estimate pooled weighted mean differences (WMDs) with 95% confidence intervals (CIs). The methodological quality of individual studies was assessed using the Cochrane Collaboration risk of bias tool. A total of 5 studies were included and analyzed using STATA software version 12. The results show that there is a significant decrease in systolic BP (WMD, -8.64 mmHg; 95% CI, -15.41 to -1.87; p ≤ 0.001) and diastolic BP (WMD, -4.87 mmHg; 95% CI, -8.37 to -1.37; p = 0.006) of patients with hypertension as compared to control groups. This study supported that flaxseed supplementation had favorable effects on BP control in hypertensive patients. It may be a promising adjuvant therapy for patients with hypertension.

Innovative insights into the roasting-driven transformation of volatile compounds and quality markers in flaxseed (Linum usitatissimum L.) oil

Roasting is essential for developing the characteristic aroma of flaxseed oil (FSO), yet its impact on oil quality remains underexplored. This study employed headspace-gas chromatography-mass spectrometry coupled with multivariate analysis to elucidate the dynamic changes in volatile compounds and quality characteristics of FSO subjected to varying roasting temperatures. Our findings revealed that seven key aroma compounds, identified through the variable importance in the projection scores of partial least square-discrimination analysis models and relative aroma activity value, served as molecular markers indicative of distinct roasting temperatures. These compounds included 2,5-dimethylpyrazine, 2-pentylfuran, (E)-2-pentenal, 2-ethyl-3,6-dimethylpyrazine, heptanal, octanal, and 2-hexenal. Notably, roasting at 200°C was found to enhance oil stability and antioxidant capacity, with phenolic compounds and Maillard reaction products playing synergistic roles in bolstering these qualities. Network analysis further uncovered significant correlations between these key aroma compounds and quality characteristics, offering novel perspectives for assessing FSO quality under diverse roasting conditions. This research not only enriched our understanding of the roasting process's impact on FSO but also provided valuable guidance for the optimization of industrial roasting practices. This study would provide important practical applications in aroma regulation and process optimization of flaxseed oil. .

Non-oxidized and oxidized flaxseed orbitides differently induce HepG2 cell apoptosis: involvement of cellular uptake and membrane death receptor DR4

BACKGROUND

Flaxseed orbitides have health-promoting properties, particularly potent anti-cancer activity. However, flaxseed orbitides containing a methionine structure, such as [1-9-NαC]-linusorb B2 (CLB), are easily oxidized to sulfoxide ([1-9-NαC],[1-Rs,Ss-MetO]-linusorb-B2 (CLC)) and sulfone ([1-9-NαC], [1-MetO]-linusorb B2 (CLK)), with CLC having less anti-cancer ability than CLB. It is unclear why oxidized flaxseed orbitides are less effective against cancer than non-oxidized flaxseed orbitide.

RESULTS

Non-oxidized ([1-9-NαC]-linusorb-B3 (CLA) and CLB) and oxidized (CLC and CLK) flaxseed orbitides were found to significantly upregulate the levels of pro-apoptotic proteins, including Bax/Bcl-2, CytoC, caspase-3, and caspase-8, in a dose-dependent manner, with non-oxidized flaxseed orbitides being more effective than oxidized flaxseed orbitides. Mechanically, the cellular absorption of non-oxidized flaxseed orbitides was higher than that of oxidized flaxseed orbitides. Moreover, the significant fluorescence quenching of DR4 protein by flaxseed orbitides (especially non-oxidized orbitides) indicated the formation of a DR4-orbitide complex. Molecular docking demonstrated that non-oxidized orbitides could easily dock into the active cavity of DR4 protein. Further blocking DR4 significantly reduced the ability of non-oxidized flaxseed orbitides to stimulate caspase-3 expression, whereas oxidized flaxseed orbitides retained this ability.

CONCLUSION

Non-oxidized flaxseed orbitides are more effective against cancer than oxidized flaxseed orbitides due to higher cellular uptake and activation of the DR4-mediated death receptor signaling pathway. © 2024 Society of Chemical Industry.

ITS and 16S rDNA metagenomic dataset of different soils from flax fields

Flax (Linum usitatissimum L.), one of the important and versatile crops, is used for the production of oil and fiber. To obtain high and stable yields of flax products, L. usitatissimum varieties should be cultivated under optimal conditions, including the composition of the soil microbiome. We evaluated the diversity of microorganisms in soils under conditions unfavorable for flax cultivation (suboptimal acidity or herbicide treatment) or infected with causative agents of harmful flax diseases (Septoria linicola, Colletotrichum lini, Melampsora lini, or Fusarium oxysporum f. sp. lini). For this purpose, twenty-two sod-podzolic soil samples were collected from flax fields and their metagenomes were analyzed using the regions of 16S ribosomal RNA gene (16S rDNA) and internal transcribed spacers (ITS) of the ribosomal RNA genes, which are used in phylogenetic studies of bacteria and fungi. Amplicons were sequenced on the Illumina MiSeq platform (reads of 300 + 300 bp). On average, we obtained 8,400 reads for ITS and 43,300 reads for 16S rDNA per sample. For identification of microorganisms in the soil samples, the Illumina reads were processed using DADA2. The raw data are deposited in the Sequence Read Archive under the BioProject accession number PRJNA956957. Tables listing the microorganisms identified in the soil samples are available in this article. The obtained dataset can be used to analyze the fungal and bacterial composition of flax field soils and their relationship to environmental conditions, including suboptimal soil acidity and infection with fungal pathogens. In addition, it can help to understand the influence of herbicide treatment on the microbial diversity of flax fields. Another useful application of our data is the ability to assess the suitability of the soil microbiome for flax cultivation.

Flaxseed Lignan Alleviates the Paracetamol-Induced Hepatotoxicity Associated with Regulation of Gut Microbiota and Serum Metabolome

This study examined the protective effect of flaxseed lignans on liver damage caused by an overdose of paracetamol (PAM). The findings demonstrated that administering 800 mg/kg/d flaxseed lignan prior to PAM significantly decreased the serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and total bilirubin (TBi) levels, while it increased liver superoxide dismutase (SOD) and glutathione (GSH) levels in mice. Flaxseed lignan renovated the gut microbiota dysbiosis induced by PAM by promoting the proliferation of sulfonolipid (SL) producing bacteria such as Alistipes and lignan-deglycosolating bacteria such as Ruminococcus while inhibiting the growth of opportunistic pathogen bacteria such as Acinetobacter and Clostridium. Furthermore, flaxseed lignan modulated the serum metabolomic profile after PAM administration, specifically in the taurine and hypotaurine metabolism, phenylalanine metabolism, and pyrimidine metabolism. The study identified eight potential biomarkers, including enterolactone, cervonyl carnitine, acutilobin, and PC (20:3(5Z, 8Z, 11Z)/20:0). Overall, the results suggest that flaxseed lignan can alleviate PAM-induced hepatotoxicity and may be beneficial in preventing drug-induced microbiome and metabolomic disorders.

Flaxseed oil fraction reverses cardiac remodeling at a molecular level: improves cardiac function, decreases apoptosis, and suppresses miRNA-29b and miRNA 1 gene expression

Flaxseed is an ancient commercial oil that historically has been used as a functional food to lower cholesterol levels. However, despite its longstanding treatment, there is currently a lack of scientific evidence to support its role in the management of cardiac remodeling. This study aimed to address this gap in knowledge by examining the molecular mechanism of standardized flaxseed oil in restoring cardiac remodeling in the heart toxicity vivo model. The oil fraction was purified, and the major components were standardized by qualitative and quantitative analysis. In vivo experimental design was conducted using isoproterenol ISO (85 mg/kg) twice subcutaneously within 24 h between each dose. The rats were treated with flaxseed oil fraction (100 mg/kg orally) and the same dose was used for omega 3 supplement as a positive control group. The GC-MS analysis revealed that α-linolenic acid (24.6%), oleic acid (10.5%), glycerol oleate (9.0%) and 2,3-dihydroxypropyl elaidate (7%) are the major components of oil fraction. Physicochemical analysis indicated that the acidity percentage, saponification, peroxide, and iodine values were 0.43, 188.57, 1.22, and 122.34 respectively. As compared with healthy control, ISO group-induced changes in functional cardiac parameters. After 28-day pretreatment with flaxseed oil, the results indicated an improvement in cardiac function, a decrease in apoptosis, and simultaneous prevention of myocardial fibrosis. The plasma levels of BNP, NT-pro-BNP, endothelin-1, Lp-PLA2, and MMP2, and cTnI and cTn were significantly diminished, while a higher plasma level of Topo 2B was observed. Additionally, miRNA - 1 and 29b were significantly downregulated. These findings provide novel insight into the mechanism of flaxseed oil in restoring cardiac remodeling and support its future application as a cardioprotective against heart diseases.

Pharmacological, nutraceutical, and nutritional properties of flaxseed (Linum usitatissimum): An insight into its functionality and disease mitigation

Flaxseed (Linum usitatissimum L.) is derived from the flax plant, an annual herb. The primary relevance of flaxseed is in the human nutrition sector, where it is emerging as a significant functional food component due to its high level of active chemicals, which have been linked to health benefits. Flaxseed may be consumed in numerous forms, including milled, oil, and bakery items. The phytochemicals that are present in flaxseed have greatly drawn interest as bioactive molecules beneficial for health. It is naturally enriched with alpha-linolenic acid, omega-3 fatty acid, lignin, secoisolariciresinol diglucoside, and fiber which are physiologically active in the protection of some chronic illnesses such as cancer, diabetes, cardiovascular disease, and cerebrovascular stroke. Furthermore, the benefits of flaxseed eating have been demonstrated in the animal nutrition industry, resulting in healthier food from animal origin. In reality, the fatty acid profile of meat and fat in swine and poultry is directly impacted by the source of fat in the diet. Feeding omega-3-enriched diets with flaxseed will improve the omega-3 content in eggs and meat, enriching the products. The current study focuses on the latest evidence on the chemical makeup of flaxseed and its positive benefits.

A comprehensive review of the health benefits of flaxseed oil in relation to its chemical composition and comparison with other omega-3-rich oils

Flaxseed (Linum usitatissimum L) is an ancient perennial plant species regarded as a multipurpose plant owing to its richness in omega-3 polyunsaturated fatty acids (PUFA) including α-linolenic acid (ALA). The extensive biochemical analysis of flaxseed resulted in the identification of its bioactive, i.e., lignans with potential application in the improvement of human health. Flaxseed oil, fibers, and lignans exert potential health benefits including reduction of cardiovascular disease, atherosclerosis, diabetes, cancer, arthritis, osteoporosis, and autoimmune and neurological disorders that have led to the diversification of flaxseed plant applications. This comprehensive review focuses on flaxseed oil as the major product of flaxseed with emphasis on the interrelationship between its chemical composition and biological effects. Effects reviewed include antioxidant, anti-inflammatory, antimicrobial, anticancer, antiulcer, anti-osteoporotic, cardioprotective, metabolic, and neuroprotective. This study provides an overview of flaxseed oil effects with the reported action mechanisms related to its phytochemical composition and in comparison, to other PUFA-rich oils. This study presents the most updated and comprehensive review summarizing flaxseed oil's health benefits for the treatment of various diseases.

Exploring the safe utilization strategy of calcareous agricultural land irrigated with wastewater for over 50 years

The trace element (TE) contamination of farmland caused by wastewater irrigation threatens food security and food safety. We selected a typical calcareous soil area in western China that has been irrigated with wastewater for >50 years to explore safe use strategies for flax farmland contaminated by cadmium (Cd) and arsenic (As). We found that Cd and As were mainly accumulated in flax roots rather than seeds. However, regardless of the type of TE and acceptor, direct ingestion of the flaxseed would seriously endanger human health (hazard quotient >1). According to the results of redundancy analysis and Pearson correlation analysis, the concentration of Cd and As in flaxseed depended on the concentration of soil total TE, Olsen phosphorus, dissolved organic carbon, soil organic matter, and active calcium carbonate (CaCO₃). This was largely because the pH and total CaCO₃ content in topsoil of flax farmland decreased by 1.05 units and 37 %, respectively, compared with their background levels before wastewater irrigation. Interestingly, after pressing, Cd and As in flaxseed transferred to flaxseed oil were 3.87-10.55 % and 17.21-30.48 %, respectively, which led to an acceptable risk of adults and children (hazard quotient <1) consuming flaxseed oil. Our results suggest that with the production of flaxseed oil as the goal, the long-term wastewater-irrigated calcareous land can be safely utilized while obtaining income.