The effect of different LED wavelengths on the components and biosynthesis of isoflavonoid in sprout Astragalus membranaceus.

An artificial light source is the optimal element for studying the usability of the medicinal plant Astragalus membranaceus as a sprout vegetable. Based on artificial light source conditions, formononetin (FO) level was the highest (2.6 mg/L) in A. membranaceus exposed to white light emitting diode (LED) light, and calycosin (CA) level was the highest (3.09 mg/L) in the plant exposed to red LED light. According to the publicly available transcriptome data of LED-exposed sprout A. membranaceus LED, reference genes related to the content enhancement of FO, an isoflavone compound, and those related to the content enhancement of CA were selected. The expression patterns of these genes were assayed using qPCR. Among the genes related to FO enhancement, Gene-225190T showed the highest mRNA levels in cells of LED-white light-exposed sprout A. membranaceus; among the genes related to CA enhancement, Gene_042770T showed the highest expression under red LED light. Most genes related to the overall biosynthesis regulation of flavonoids of the upper concept of isoflavone were highly expressed in response to red LED light, and the transcriptional level of 4CL in response to red LED light was the highest. Based on these results, the artificial light sources that regulated the FO and CA contents in sprouts A. membranaceus were white and red LED lights, and the selected reference genes were capable of regulating isoflavone biosynthesis.

Antioxidant and Antiproliferative Activities of Eclipta prostrata (L.) L. Extract and Isolated Compounds.

The primary objective of this study was to elucidate the chemical composition, antioxidant properties, and antiproliferative activities of Eclipta prostrata extracts. Two flavonoids, 3'-O-methylorobol and apigenin 7-sulfate, were isolated from the ethyl acetate (EtOAc) extract of E. prostrata. The total phenolic and flavonoid contents of the E. prostrata extracts, as well as their overall antioxidant activities as measured using the 2,2-diphenyl-1-picrylhydrazyl and reducing power assays, were investigated. The E. prostrata EtOAc extract exhibited significantly greater antioxidant activities in both assays and higher phenol and flavonoid contents than the other extracts. The potential antiproliferative properties of the E. prostrata extracts and isolated compounds were investigated in vitro against the AGS, A549, and HT-29 cancer cell lines and the normal human HEK-293 cell line using the MTT assay. Annexin V-FITC/PI staining analysis and quantitative real-time PCR were used to assess AGS cell apoptosis. At a concentration of 100 µg/mL, the EtOAc extract of E. prostrata reduced AGS cell viability and proliferation by inducing apoptosis through the alteration of gene expression in the apoptotic cascade. These results highlight E. prostrata as a promising source of anticancer compounds.

Cellular Morphology and Transcriptome Comparative Analysis of Astragalus membranaceus Bunge Sprouts Cultured In Vitro under Different LED Light.

Astragalus membranaceus, the major components of which are saponins, flavonoids, and polysaccharides, has been established to have excellent pharmacological activity. After ginseng, it is the second most used medicinal plant. To examine the utility of A. membranaceus as a sprout crop for plant factory cultivation, we sought to establish a functional substance control model by comparing the transcriptomes of sprouts grown in sterile, in vitro culture using LED light sources. Having sown the seeds of A. membranaceus, these were exposed to white LED light (continuous spectrum), red LED light (632 nm, 1.58 µmol/m2/s), or blue LED light (465 nm, 1.44 µmol/m2/s) and grown for 6 weeks; after which, the samples were collected for transcriptome analysis. Scanning electron microscopy analysis of cell morphology in plants exposed to the three light sources revealed that leaf cell size was largest in those plants exposed to red light, where the thickest stem was observed in plants exposed to white light. The total number of genes in A. membranaceus spouts determined via de novo assembly was 45,667. Analysis of differentially expressed genes revealed that for the comparisons of blue LED vs. red LED, blue LED vs. white LED, and red LED vs. white LED, the numbers of upregulated genes were 132, 148, and 144, respectively. Binding, DNA integration, transport, phosphorylation, DNA biosynthetic process, membrane, and plant-type secondary cell wall biogenesis were the most enriched in the comparative analysis of blue LED vs. red LED, whereas Binding, RNA-templated DNA biosynthetic process, DNA metabolic process, and DNA integration were the most enriched in the comparative analysis of blue vs. white LED, and DNA integration and resolution of meiotic recombination intermediates were the most enrichment in the comparison between red LED vs. white LED. The GO term associated with flavonoid biosynthesis, implying the functionality of A. membranaceus, was the flavonoid biosynthetic process, which was enriched in the white LED vs. red LED comparison. The findings of this study thus indicate that different LED light sources can differentially influence the transcriptome expression pattern of A. membranaceus sprouts, which can provide a basis for establishing a flavonoid biosynthesis regulation model and thus, the cultivation of high-functional Astragalus sprouts.

Evaluation of Growth Characteristics and Biological Activities of 'Dachul', a Hybrid Medicinal Plant of Atractylodes macrocephala × Atractylodes japonica, under Different Artificial Light Sources.

This study was conducted to evaluate the effects of different artificial light sources on the growth characteristics and various biological activities of the Atractylodes macrocephala x Atractylodes japonica hybrid cv. 'Dachul', which is highly useful for medicinal purposes. The plant had the largest biomass with a plant height of 38.20 ± 1.95 cm when treated with microwave electrodeless light (MEL). The chlorophyll content of the plants treated with fluorescent light (FL) was 53.93 ± 1.05 SPAD and was the highest. The antioxidant effect, determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), was the highest with 92.7 ± 0.2% in plants treated with light-emitting diode (LED)-green light. Total phenol and flavonoid contents were significantly higher with 19.7 ± 0.5 mg GAE/g and 40.2 ± 2.2 mg QE/g in the sample treated with LED-green light, respectively. For antimicrobial activity using the minimum inhibitory concentration (MIC) technique, the inhibitory ability against Escherichia coli was at 0.25 mg/mL under LED-green light treatment. The whitening activity using tyrosinase enzyme showed the highest tyrosinase inhibitory ability at 62.1 ± 1.2% of the above extract treated with MEL light. To confirm the immune activity in lipopolysaccharide (LPS)-induced RAW 264.7 cells, NO production of inflammation-related substances was measured. In addition, the inflammation-related genes iNOS (inducible nitric oxide synthase), COX-2 (cyclooxygenase-2), and TNF-α (tumor necrosis factor-α) in the same sample were confirmed using reverse transcriptase (RT)-PCR, and the result showed that gene expression was suppressed compared with that in the control group. It is expected that Dachul plants treated with LED-blue light will play an important role in enhancing intracellular anti-inflammatory activity. From these results, the effect for various biological activities appeared in a significantly diverse spectrum in response to different wavelengths of artificial light sources in Dachul.

Enrichment of genomic resources and identification of simple sequence repeats from medicinally important Clausena excavata.

To broaden and delve into the genomic information of Clausena excavata, an important medicinal plant in many Asian countries, RNA sequencing (RNA-seq) analysis was performed and a total of 16,638 non-redundant unigenes (≥ 300 bp) with an average length of 755 bp were generated by de novo assembly from 17,580,456 trimmed clear reads. The functional categorization of the identified unigenes by a gene ontology (GO) term resulted in 2305 genes in the cellular component, 5577 in the biological processes, and 8056 in the molecular functions, respectively. The top sub-category in biological processes was the metabolic process with 4374 genes. Among annotated genes, 3006 were mapped to 123 metabolic pathways by the Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathway analysis tool. The search for simple sequence repeats (SSRs) resulted in 845 SSRs from 749 SSR-containing unigenes and the most abundant SSR motifs was AAG/CTT with 179 occurrences. Twelve SSR markers were tested for cross transferability among five Clausena species; eight of them exhibited polymorphism. Taken together, these data provide valuable resources for genomic or genetic studies of Clausena species and other relative studies. The transcriptome shotgun assembly data have been deposited at DDBJ/EMBL/GenBank under the accession GGEM00000000.

Expressed Sequence Tags Analysis and Design of Simple Sequence Repeats Markers from a Full-Length cDNA Library in Perilla frutescens (L.).

Perilla frutescens is valuable as a medicinal plant as well as a natural medicine and functional food. However, comparative genomics analyses of P. frutescens are limited due to a lack of gene annotations and characterization. A full-length cDNA library from P. frutescens leaves was constructed to identify functional gene clusters and probable EST-SSR markers via analysis of 1,056 expressed sequence tags. Unigene assembly was performed using basic local alignment search tool (BLAST) homology searches and annotated Gene Ontology (GO). A total of 18 simple sequence repeats (SSRs) were designed as primer pairs. This study is the first to report comparative genomics and EST-SSR markers from P. frutescens will help gene discovery and provide an important source for functional genomics and molecular genetic research in this interesting medicinal plant.

Improved antioxidant activity in transgenic Perilla frutescens plants via overexpression of the γ-tocopherol methyltransferase (γ-tmt) gene.

The main goal of this study was to generate transgenic Perilla frutescens with enhanced antioxidant properties by overexpressing the γ-tocopherol methyltransferase (γ-tmt) gene. In this study, the antioxidant activity of methanolic crude extracts of transgenic and non-transgenic control plants was investigated using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method. Free radical scavenging activity was evaluated using α-tocopherol and butylated hydroxyl toluene as standard antioxidants. In general, the ethyl acetate fraction of transgenic P. frutescens showed stronger DPPH radical scavenging activity than the ethyl acetate fraction from non-transgenic control plants (IC50 2.00 ± 0.10 and 5.53 ± 0.40 µg ∙ ml(-1), respectively). High-performance liquid chromatography analysis of phenolic acids in leaf extracts confirmed increased levels of 16 individual phenolic compounds in two transgenic lines (pf47-5 and pf47-8) compared with control plants. Changes in the phenolic compound profile and α-tocopherol content were correlated with the antioxidant properties of transgenic plants, indicating that the introduction of transgene γ-tmt influenced the metabolism of phenolic compounds and subsequently produced biochemical changes in the transformants. There were no significant differences in photosynthetic rate in the transgenic plants as compared to the non-transgenic control plants, suggesting that the alteration of phenolic compounds and tocopherol composition had little impact on photosynthesis.