A review of flaxseed lignan and the extraction and refinement of secoisolariciresinol diglucoside

Lignan is a class of diphenolic compounds that arise from the condensation of two phenylpropanoid moieties. Oilseed and cereal crops (e.g., flaxseed, sesame seed, wheat, barley, oats, rye, etc.) are major sources of plant lignan. Methods for commercial isolation of the lignan secoisolariciresinol diglucoside (SDG) are not well reported, as most publications describing the detection, extraction, and enrichment of SDG use methods that have not been optimized for commercial scale lignan recovery. Simply scaling up laboratory methods would require expensive infrastructure to achieve a marketable yield and reproducible product quality. Therefore, establishing standard protocols to produce SDG and its derivatives on an industrial scale is critical to decrease lignan cost and increase market opportunities. This review summarizes the human health benefits of flaxseed lignan consumption, lignan physicochemical properties, and mammalian lignan metabolism, and describes methods for detecting, extracting, and enriching flaxseed lignan. Refining and optimization of these methods could lead to the development of inexpensive lignan sources for application as an ingredient in medicines, dietary supplements, and other healthy ingredients.

Data on genetic polymorphism of flax (Linum usitatissimum L.) pathogenic fungi of Fusarium, Colletotrichum, Aureobasidium, Septoria, and Melampsora genera

Being a valuable agricultural plant, flax (Linum usitatissimum L.) is used for oil and fiber production. However, the cultivation of this agriculture faces an urgent problem of flax susceptibility to fungal diseases. The most destructive ones are caused by the representatives of Fusarium, Colletotrichum, Aureobasidium, Septoria, and Melampsora genera, reducing flax yields significantly. To combat such pathogens effectively, it is of high importance to assess their genetic diversity that can be used to develop molecular markers to distinguish fungal genera and species. Morphological analysis traditionally carried out for fungal identification requires a given amount of time and tends to be difficult. In the present work, we determined the DNA sequences that are frequently used for phylogenetic studies in fungi - internal transcribed spacer (ITS) and beta-tubulin (tub2), translation elongation factor 1-alpha (tef1), RNA polymerase II largest subunit (RPB1), RNA polymerase II second largest subunit (RPB2), and minichromosome maintenance protein (MCM7) genes - for 203 flax fungal pathogens of Fusarium oxysporum, F. avenaceum, F. solani, F. sporotrichiella, F. moniliforme, F. culmorum, F. semitectum, F. gibbosum, Colletotrichum lini, Aureobasidium pullulans, Septoria linicola, and Melampsora lini species. The sequencing was performed using the Illumina MiSeq platform with a 300+300 bp kit, and on average, about 2350 reads per sample were obtained that allows accurate identification of the genetic polymorphism. Raw data are stored at the Sequence Read Archive under the accession number PRJNA596387. The obtained data can be used for fungal phylogenetic studies and the development of a PCR-based test system for flax pathogen identification.

Cadmium accumulation, translocation, and assessment of eighteen Linum usitatissimum L. cultivars growing in heavy metal contaminated soil

Flax (Linum usitatissimum L.) is suitable for growing in heavy metal polluted soil for non-food purposes and can be used as potential crops for cleaning the soil from heavy metals. The main objective of this study was to investigate flax/linseed phytoextraction of cadmium (Cd), including uptake, translocation, and accumulation differences in organs among flax/linseed cultivars. A field experiment was carried out in Cd contaminated field of Chinese southern area with nine flax, one dual-purpose, and eight linseed cultivars. Cd concentrations in plant organs (root, xylem, phloem, and capsule) and biomass of different organs of each cultivar were measured and evaluated. Significant differences in Cd concentration and accumulation among organs were observed. The most Cd was accumulated by phloem, which was 2 ∼ 4 times more than other organs, followed by roots, xylems and capsules played a comparably smaller role. The uptake of Cd by flax/linseed from per hectare was calculated and had highly significant positive correlation with biomass. Phloem accumulated 45 ∼ 55% of total Cd from the soil by the plant. Among testing 18 flax/linseed cultivars, one flax cultivar (Zhongya 1), and two linseed cultivars (Y2I329 and Y2I330), which extracted more than 60 g ha^-1, can be considered as Cd accumulators for phytoremediation of Cd contaminated soil.

The Analgesic and Anti-Inflammatory Activity of Linum usitatissimum in Balb/c Mice

Linum usitatissimum L is traditionally used for relief of pain and inflammation. In this study, the analgesic and anti-inflammatory effects of this plant were evaluated. Xylene test was used for anti-inflammatory evaluation in which 48 mice were randomly designated into 6 groups of 8 each including: control, dexamethasone as positive control (15 mg/kg), and experimental groups (42, 85, 170, and 340 mg/kg, respectively). For analgesic evaluation, 192 mice were randomly designated into 4 sets of 6 groups of 8 mice, including control, morphine as positive control, morphine plus naloxone, experimental groups (200 and 500 mg/kg extract), and extract along with naloxone group, which received 500 mg/kg. The analgesic activities were evaluated at 5, 15, 30, and 60 minutes, respectively, in each set. Both doses showed analgesic activity, the 200 mg/kg possessed higher effects (P < .05). Naloxone reduced a section of its effect (P < .001). The 170 mg/kg dose of the extract showed anti-inflammatory activity (P < .05). The extract had phenolic, flavonoid, and flavonol compounds with antioxidant activity. Linum usitatissimum L dose dependently had analgesic activity partially like morphine and might be used as analgesic and anti-inflammatory agent.

Thidiazuron-enhanced biosynthesis and antimicrobial efficacy of silver nanoparticles via improving phytochemical reducing potential in callus culture of Linum usitatissimum L

Green synthesis of silver nanoparticles (AgNPs) by using plants is an emerging class of nanobiotechnology. It revolutionizes all domains of medical sciences by synthesizing chemical-free AgNPs for various biomedical applications. In this report, AgNPs were successfully synthesized by using whole plant extract (WPE) and thidiazuron-induced callus extract (CE) of Linum usitatissimum. The phytochemical analysis revealed that the total phenolic and flavonoid contents were higher in CE than that in WPE. Ultraviolet-visible spectroscopy of synthesized AgNPs showed a characteristic surface plasmon band in the range of 410–426 nm. Bioreduction of CE-mediated AgNPs was completed in a shorter time than that of WPE-mediated AgNPs. Scanning electron microscopy showed that both types of synthesized AgNPs were spherical in shape, but CE-mediated AgNPs were smaller in size (19–24 nm) and more scattered in distribution than that of WPE-mediated AgNPs (49–54 nm). X-ray diffraction analysis confirmed crystalline nature (face-centered cubic) of both types of AgNPs. Fourier-transform infrared spectroscopy revealed that the polyphenols and flavonoids were mainly responsible for reduction and capping of synthesized AgNPs. Energy dispersive X-ray analysis further confirmed the successful synthesis of AgNPs. Moreover, the synthesized AgNPs were found to be stable over months with no change in the surface plasmon bands. More importantly, CE-mediated AgNPs displayed significantly higher bactericidal activity against multiple drug-resistant human pathogens than WPE-mediated AgNPs. The present work highlighted the potent role of thidiazuron in in vitro-derived cultures for enhanced biosynthesis of chemical-free AgNPs, which can be used as nanomedicines in many biomedical applications.