Choline Dehydrogenase Contributes to Salt Tolerance in Dunaliella through Betaine Synthesis.

In Dunaliella tertiolecta, a microalga renowned for its extraordinary tolerance to high salinity levels up to 4.5 M NaCl, the mechanisms underlying its stress response have largely remained a mystery. In a groundbreaking discovery, this study identifies a choline dehydrogenase enzyme, termed DtCHDH, capable of converting choline to betaine aldehyde. Remarkably, this is the first identification of such an enzyme not just in D. tertiolecta but across the entire Chlorophyta. A 3D model of DtCHDH was constructed, and molecular docking with choline was performed, revealing a potential binding site for the substrate. The enzyme was heterologously expressed in E. coli Rosetta (DE3) and subsequently purified, achieving enzyme activity of 672.2 U/mg. To elucidate the role of DtCHDH in the salt tolerance of D. tertiolecta, RNAi was employed to knock down DtCHDH gene expression. The results indicated that the Ri-12 strain exhibited compromised growth under both high and low salt conditions, along with consistent levels of DtCHDH gene expression and betaine content. Additionally, fatty acid analysis indicated that DtCHDH might also be a FAPs enzyme, catalyzing reactions with decarboxylase activity. This study not only illuminates the role of choline metabolism in D. tertiolecta's adaptation to high salinity but also identifies a novel target for enhancing the NaCl tolerance of microalgae in biotechnological applications.

DbMADS regulates carotenoid metabolism by repressing two carotenogenic genes in the green alga Dunaliella sp. FACHB-847.

MADS transcription factors are involved in the regulation of fruit development and carotenoid metabolism in plants. However, whether and how carotenoid accumulation is regulated by algal MADS are largely unknown. In this study, we first used functional complementation to confirm the functional activity of phytoene synthase from the lutein-rich Dunaliella sp. FACHB-847 (DbPSY), the key rate-limiting enzyme in the carotenoid biosynthesis. Promoters of DbPSY and DbLcyB (lycopene ß-cyclase) possessed multiple cis-acting elements such as light-, UV-B-, dehydration-, anaerobic-, and salt-responsive elements, W-box, and C-A-rich-G-box (MADS-box). Meanwhile, we isolated one nucleus-localized MADS transcription factor (DbMADS), belonging to type I MADS gene. Three carotenogenic genes, DbPSY, DbLcyB, and DbBCH (ß-carotene hydroxylase) genes were upregulated at later stages, which was well correlated with the carotenoid accumulation. In contrast, DbMADS gene was highly expressed at lag phase with low carotenoid accumulation. Yeast one-hybrid assay and dual-luciferase reporter assay demonstrated that DbMADS could directly bind to the promoters of two carotenogenic genes, DbPSY and DbLcyB, and repress their transcriptions. This study suggested that DbMADS may act as a negative regulator of carotenoid biosynthesis by repressing DbPSY and DbLcyB at the lag phase, which provide new insights into the regulatory mechanisms of carotenoid metabolism in Dunaliella.

The expression pattern of ß-carotene ketolase gene restricts the accumulation of astaxanthin in Dunaliella under salt stress.

Dunaliella salina can accumulate a large amount of ß-carotene which is generally considered to be its terminal product of carotenoid metabolism. In this study, it was proved that D. salina has the ketolase (DsBKT) of catalyzing the synthesis of astaxanthin, the downstream products of ß-carotene. Therefore, the reason why D. salina does not synthesize astaxanthin is the purpose of this study. The enzymatic activity of DsBKT was detected by functional complementation assays in Escherichia coli, results showed that DsBKT had efficient ketolase activity toward ß-carotene and zeaxanthin to produce astaxanthin, indicating that there were complete astaxanthin-producing genes in Dunaliella. Unlike the induced expression of Lycopene cyclase (catalyzing ß-carotene synthesis) under salt stress, the expression of DsBKT was very low under both normal and stress conditions, which may be the main reason why D. salina cannot accumulate astaxanthin. On the contrary, with the astaxanthin-rich Haematococcus pluvialis as a control, its BKT gene was significantly upregulated under salt stress. Further study showed that DsBKT promoter had strong promoter ability and could stably drive the expression of ble-egfp in D. salina. Obviously, DsBKT promoter is not the reason of DsBKT not being expressed which may be caused by Noncoding RNA.

Regulation of carotenoid degradation and production of apocarotenoids in natural and engineered organisms.

Carotenoids are important precursors of a wide range of apocarotenoids with their functions including: hormones, pigments, retinoids, volatiles, and signals, which can be used in the food, flavors, fragrances, cosmetics, and pharmaceutical industries. This article focuses on the formation of these multifaceted apocarotenoids and their diverse biological roles in all living systems. Carotenoid degradation pathways include: enzymatic oxidation by specific carotenoid cleavage oxygenases (CCOs) or nonspecific enzymes such as lipoxygenases and peroxidases and non-enzymatic oxidation by reactive oxygen species. Recent advances in the regulation of carotenoid cleavage genes and the biotechnological production of multiple apocarotenoids are also covered. It is suggested that different developmental stages and environmental stresses can influence both the expression of carotenoid cleavage genes and the formation of apocarotenoids at multiple levels of regulation including: transcriptional, transcription factors, posttranscriptional, posttranslational, and epigenetic modification. Regarding the biotechnological production of apocarotenoids especially: crocins, retinoids, and ionones, enzymatic biocatalysis and metabolically engineered microorganisms have been a promising alternative route. New substrates, carotenoid cleavage enzymes, biosynthetic pathways for apocarotenoids, and new biological functions of apocarotenoids will be discussed with the improvement of our understanding of apocarotenoid biology, biochemistry, function, and formation from different organisms.

Transgenic microalgae as bioreactors.

Microalgae are unicellular organisms that act as the crucial primary producers all over the world, typically found in marine and freshwater environments. Most of them can live photo-autotrophically, reproduce rapidly, and accumulate biomass in a short period efficiently. To adapt to the uninterrupted change of the environment, they evolve and differentiate continuously. As a result, some of them evolve special abilities such as toleration of extreme environment, generation of sophisticated structure to adapt to the environment, and avoid predators. Microalgae are believed to be promising bioreactors because of their high lipid and pigment contents. Genetic engineering technologies have given revolutions in the microalgal industry, which decoded the secrets of microalgal genes, express recombinant genes in microalgal genomes, and largely soar the accumulation of interested components in transgenic microalgae. However, owing to several obstructions, the industry of transgenic microalgae is still immature. Here, we provide an overview to emphasize the advantage and imperfection of the existing transgenic microalgal bioreactors.

Two-Stage Cultivation of Dunaliella tertiolecta with Glycerol and Triethylamine for Lipid Accumulation: a Viable Way To Alleviate the Inhibitory Effect of Triethylamine on Biomass.

Microalgae are promising alternatives for sustainable biodiesel production. Previously, it was found that 100 ppm triethylamine greatly enhanced lipid production and lipid content per cell of Dunaliella tertiolecta by 20% and 80%, respectively. However, triethylamine notably reduced biomass production and pigment contents. In this study, a two-stage cultivation with glycerol and triethylamine was attempted to improve cell biomass and lipid accumulation. At the first stage with 1.0 g/liter glycerol addition, D. tertiolecta cells reached the late log phase in a shorter time due to rapid cell growth, leading to the highest cell biomass (1.296 g/liter) for 16 days. However, the increased glycerol concentrations with glycerol addition decreased the lipid content. At the second-stage cultivation with 100 ppm triethylamine, the highest lipid concentration and lipid weight content were 383.60 mg/liter and 37.7% of dry cell weight (DCW), respectively, in the presence of 1.0 g/liter glycerol, which were 27.36% and 72.51% higher than those of the control group, respectively. Besides, the addition of glycerol alleviated the inhibitory effect of triethylamine on cell morphology, algal growth, and pigment accumulation in D. tertiolecta The results indicated that two-stage cultivation is a viable way to improve lipid yield in microalgae.IMPORTANCE Microalgae are promising alternatives for sustainable biodiesel production. Two-stage cultivation with glycerol and triethylamine enhanced the lipid productivity of Dunaliella tertiolecta, indicating that two-stage cultivation is an efficient strategy for biodiesel production from microalgae. It was found that glycerol significantly enhanced cell biomass of D. tertiolecta, and the presence of glycerol alleviated the inhibitory effect of triethylamine on algal growth. Glycerol, the major byproduct from biodiesel production, was used for the biomass accumulation of D. tertiolecta at the first stage of cultivation. Triethylamine, as a lipid inducer, was used for lipid accumulation at the second stage of cultivation. Two-stage cultivation with glycerol and triethylamine enhanced lipid productivity and alleviated the inhibitory effect of triethylamine on the algal growth of D. tertiolecta, which is an efficient strategy for lipid production from D. tertiolecta.

Antidepressant active ingredients from herbs and nutraceuticals used in TCM: pharmacological mechanisms and prospects for drug discovery.

Depression is a widespread psychological disorder that affects up to 20% of the world's population. Traditional Chinese medicine (TCM), with its unique curative effect in depression treatment, is gaining increasing attention as the discovery of novel antidepressant drug has become the pursuit of pharmaceutical. This article summarizes the work done on the natural products from TCM that have been reported to conceive antidepressant effects in the past two decades, which can be classified according to various mechanisms including increasing synaptic concentrations of monoamines, alleviating the hypothalamic-pituitary-adrenal (HPA) axis dysfunctions, lightening the impairment of neuroplasticity, fighting towards immune and inflammatory dysregulation. The antidepressant active ingredients identified can be generally divided into saponins, flavonoids, alkaloids, polysaccharides and others. Albiflorin, Baicalein, Berberine chloride, beta-Asarone, cannabidiol, Curcumin, Daidzein, Echinocystic acid (EA), Emodin, Ferulic acid, Gastrodin, Genistein, Ginsenoside Rb1, Ginsenoside Rg1, Ginsenoside Rg3, Hederagenin, Hesperidin, Honokiol, Hyperoside, Icariin, Isoliquiritin, Kaempferol, Liquiritin, L-theanine, Magnolol, Paeoniflorin, Piperine, Proanthocyanidin, Puerarin, Quercetin, Resveratrol (trans), Rosmarinic acid, Saikosaponin A, Senegenin, Tetrahydroxystilbene glucoside and Vanillic acid are Specified in this review. Simultaneously, chemical structures of the active ingredients with antidepressant activities are listed and their sources, models, efficacy and mechanisms are described. Chinese compound prescription and extracts that exert antidepressant effects are also introduced, which may serve as a source of inspiration for further development. In the view of present study, the antidepressant effect of certain TCMs are affirmative and encouraging. However, there are a lot of work needs to be done to evaluate the exact therapeutic effects and mechanisms of those active ingredients, specifically, to establish a unified standard for diagnosis and evaluation of curative effect.

Citrus aurantium L. var. amara Engl. inhibited lipid accumulation in 3T3-L1 cells and Caenorhabditis elegans and prevented obesity in high-fat diet-fed mice.

Natural products with anti-obesity effects and few side effects have attracted great attention recently. Citrus aurantium L. var. amara Engl. (CAVA) is popularly consumed as an edible and medicinal resource in China. However, its anti-obesity effects were poorly understood. The anti-obesity effects of CAVA extracts were systematically evaluated using 3T3-L1 cells, Caenorhabditis elegans (C. elegans) and high fat diet (HFD)-fed mice. Flavonoid-rich (EA) extracts with neohesperidin, hesperidin and naringin comprising 32.15%, were isolated from CAVA. EA extracts treatment significantly inhibited differentiation of 3T3-L1 preadipocytes by modulating lipid metabolism-related mediators. EA extracts supplementation also inhibited antioxidant responses in C. elegans by decreasing reactive oxygen species generation and malonaldehyde value, and increasing superoxide dismutase content. EA extracts feeding markedly decreased triglyceride (TG) content, and affected expression of genes involved in lipid and glucose metabolism in wild type C. elegans. TG content in mdt-15 (XA7702) mutants was not decreased by EA extracts administration, suggesting that EA extracts treatment might inhibit lipid accumulation in C. elegans dependent on mdt-15. EA extracts intervention further reduced body weight gain and modulated plasma biochemical parameters in HFD-fed mice. EA extracts treatment prevented HFD-induced epididymal adipose hypertrophy, liver oxidative injuries and steatosis. EA extracts administration also strongly prevented HFD-induced reduction of gut microbial diversity, decreased the Firmicutes-to-Bacteroidetes ratio and the Erysipelotrichaceae abundance, and enhanced the Bifidobacteriace abundance in HFD-fed mice. EA extracts from blossoms of CAVA were excellent antiobesogenic candidates that acted through multiple mechanisms that acted simultaneously.

High-value bioproducts from microalgae: Strategies and progress.

Microalgae have been considered as alternative sustainable resources for high-value bioproducts such as lipids (especially triacylglycerides [TAGs]), polyunsaturated fatty acids (PUFAs), and carotenoids, due to their relatively high photosynthetic efficiency, no arable land requirement, and ease of scale-up. It is of great significance to exploit microalgae for the production of high-value bioproducts. How to improve the content or productivity of specific bioproducts has become one of the most urgent challenges. In this review, we will describe high-value bioproducts from microalgae and their biosynthetic pathways (mainly for lipids, PUFAs, and carotenoids). Recent progress and strategies for the enhanced production of bioproducts from microalgae are also described in detail, and these strategies take advantages of optimized cultivation conditions with abiotic stress, chemical stress (addition of metabolic precursors, phytohormones, chemical inhibitors, and chemicals inducing oxidative stress response), and molecular approaches such as metabolic engineering, transcriptional engineering, and gene disruption strategies (mainly RNAi, antisense RNA, miRNA-based knockdown, and CRISPR/Cas9).

Carotenoids biosynthesis and cleavage related genes from bacteria to plants.

Carotenoids are essential for photosynthesis and photoprotection in photosynthetic organisms and beneficial for human health. Apocarotenoids derived from carotenoid degradation can serve critical functions including hormones, volatiles, and signals. They have been used commercially as food colorants, animal feed supplements, and nutraceuticals for cosmetic and pharmaceutical purposes. This review focuses on the molecular evolution of carotenogenic enzymes and carotenoid cleavage oxygenases (CCOs) from bacteria, fungi, cyanobacteria, algae, and plants. The diversity of carotenoids and apocarotenoids as well as their complicated biosynthetic pathway in different species can shed light on the history of early molecular evolution. Some carotenogenic genes (such as phytoene synthases) have high protein sequence similarity from bacteria to land plants, but some (such as phytoene desaturases, lycopene cyclases, carotenoid hydroxylases, and CCOs) have low similarity. The broad diversity of apocarotenoid volatile compounds can be attributed to large numbers of carotenoid precursors and the various cleavage sites catalyzed by CCOs enzymes. A variety of carotenogenic enzymes and CCOs indicate the functional diversification of carotenoids and apocrotenoids in different species. New carotenoids, new apocarotenoids, new carotenogenic enzymes, new CCOs, and new pathways still need to be explored.

The salt-regulated element in the promoter of lycopene ß-cyclase gene confers a salt regulatory pattern in carotenogenesis of Dunaliella bardawil.

In the carotenoid biosynthesis, lycopene ß-cyclase (LCYb) is a key regulatory enzyme involved in the conversion of lycopene into ß-carotene. Under stress conditions, such as high salinity, high light and nutrient deprivation, large amounts of ß-carotene can be accumulated in Dunaliella bardawil. To study on the molecular responses of salt stress in D. bardawil is of great significance to reveal the mechanisms of salt tolerance and engineer crop plants to be salt-tolerant. In this study, the full-length coding sequence of lcyb from D. bardawil (Dblcyb, GenBank: KX218392) was isolated by transcriptome sequencing. Then, the genomic sequence, promoter and terminator regions of Dblcyb were isolated by genome walking. The Dblcyb promoter (GenBank: KX218393) contained several typical transcription boxes, multiple light response elements and a salt-regulated element (SRE, GT1GMSCAM4). Dbpsy and Dblcyb responsible for ß-carotene biosynthesis in D. bardawil was shown to be up-regulated under salt stress and their promoters contained the common SRE. By element deletion analysis and using Ble-EGFP as the reporter, the salt-inducible SRE was confirmed to confer salt-induced expression of Dblcyb promoter. It was indicated that the salt-regulated expression of Dblcyb may be attributed to the salt-responsive element (GT1GMSCAM4) and the GT-rich region in its genomic sequence.

Identification of bioactives from Astragalus chinensis L.f. and their antioxidant, anti-inflammatory and anti-proliferative effects.

This work was designed to obtain the valuable compounds with antioxidant, anti-proliferative and anti-inflammatory activities from Astragalus chinensis. Ethyl acetate fraction obtained from A. chinensis L.f. had significant antioxidant, anti-proliferative and anti-inflammatory activities. Subsequently, five single compounds were separated and purified, which were identified as formononetin (1), rhamnocitrin (2), calycosin (3), ß-daucosterol (4), rhamnocitrin-3-O-ß-d-glucoside (5). The results displayed that formononetin and rhamnocitrin exhibited significant cytotoxicity actions against tumor cell lines. Calycosin exerted the strongest anti-inflammatory effect of inhibition effects on NO production in macrophages.

Curcumin liposomes prepared with milk fat globule membrane phospholipids and soybean lecithin.

Using thin film ultrasonic dispersion method, the curcumin liposomes were prepared with milk fat globule membrane (MFGM) phospholipids and soybean lecithins, respectively, to compare the characteristics and stability of the 2 curcumin liposomes. The processing parameters of curcumin liposomes were investigated to evaluate their effects on the encapsulation efficiency. Curcumin liposomes were characterized in terms of size distribution, ζ-potential, and in vitro release behavior, and then their storage stability under various conditions was evaluated. The curcumin liposomes prepared with MFGM phospholipids had an encapsulation efficiency of about 74%, an average particle size of 212.3 nm, and a ζ-potential of -48.60 mV. The MFGM liposomes showed higher encapsulation efficiency, smaller particle size, higher absolute value of ζ-potential, and slower in vitro release than soybean liposomes. The retention rate of liposomal curcumin was significantly higher than that of free curcumin. The stability of the 2 liposomes under different pH was almost the same, but MFGM liposomes displayed a slightly higher stability than soybean liposomes under the conditions of Fe(3+), light, temperature, oxygen, and relative humidity. In conclusion, MFGM phospholipids have potential advantages in the manufacture of curcumin liposomes used in food systems.

Neuroprotective and Anti-Inflammatory Effects of Diphenylheptanes from the Fruits of Amomum tsaoko, a Chinese Spice.

Two novel diphenylheptanes, 2,3- dihydro-2 - (4' - hydroxy-phenylethyl) - 6 - [(3″,4″ - dihydroxy-5" - methoxy) phenyl] -4 - pyrone (CG-A) and 4 - dihydro-2 - (4' - hydroxy-phenylmethyl) -6 - [(3",4″ - dihydroxy-5″ - methoxyphenyl) methylene]-pyran-3, 5 - dione (CG-B), were isolated from the dried fruits of Amomum tsaoko, a commercially important spice. This study was designed to investigate their protective effects against H2O2-induced nerve injury, using PC-12 cells to determine the cell cytotoxicity and cell viability. The inhibitory effect on (nitric oxide) NO production was also determined in (lipopolysaccharide) LPS-stimulated macrophage RAW 264.7 cells. The results showed that CG-A and CG-B displayed significant neuroprotective effect and exhibited anti-inflammatory activity in a dose-dependent manner. These findings suggest that CG-A and CG-B are very important nutritional ingredients responsible for the neuroprotective and anti-inflammatory health benefits of A. tsaoko.

Hypoosmotic expression of Dunaliella bardawil ζ-carotene desaturase is attributed to a hypoosmolarity-responsive element different from other key carotenogenic genes.

Some key carotenogenic genes (crts) in Dunaliella bardawil are regulated in response to salt stress partly due to salt-inducible cis-acting elements in their promoters. Thus, we isolated and compared the ζ-carotene desaturase (Dbzds) promoter with other crts promoters including phytoene synthase (Dbpsy), phytoene desaturase (Dbpds), and lycopene ß-cyclase1 (DblycB1) to identify salt-inducible element(s) in the Dbzds promoter. In silico analysis of the Dbzds promoter found several potential cis-acting elements, such as abscisic acid response element-like sequence, myelocytomatosis oncogene1 recognition motif, AGC box, anaerobic motif2, and activation sequence factor1 binding site. Remarkably, instead of salt-inducible elements, we found a unique regulatory sequence architecture in the Dbzds promoter: a hypoosmolarity-responsive element (HRE) candidate followed by a potential hypoosmolarity-inducible factor GBF5 binding site. Deletion experiments demonstrated that only HRE, but not the GBF5 binding site, is responsible for hypoosmotic expression of the fusion of Zeocin resistance gene (ble) to the enhanced green fluorescent protein (egfp) chimeric gene under salt stress. Dbzds transcripts were in accordance with those of ble-egfp driven by the wild-type Dbzds promoter. Consequently, Dbzds is hypoosmotically regulated by its promoter, and HRE is responsible for this hypoosmotic response. Finally, the hypoosmolarity mechanism of Dbzds was studied by comparing transcript profiles and regulatory elements of Dbzds with those of Dbpsy, Dbpds, DblycB1, and DblycB2, revealing that different induction characteristics of crts may correlate with regulatory sequence architecture.

Mutation breeding of Saccharomyces cerevisiae with lower methanol content and the effects of pectinase, cellulase and glycine in sugar cane spirits.

BACKGROUND: To decrease the methanol content of the sugar cane sprits, mutagenesis of ultraviolet (UV) coupled with diethyl sulfate (DES) was used to generate a mutant of Saccharomyces cerevisiae with lower methanol content. Meanwhile, the effects of the additions of pectinase, cellulase and glycine on the production of methanol in sugar cane spirits were evaluated. RESULTS: After mutagenesis of UV coupled with DES, a mutant S. cerevisiae DU9 with low production of methanol (97.3 ± 1.7 mg/L) was selected, with a 12.3% decrease of that of S. cerevisiae D4 only with DES treatment, and with a 27.8% reduction of that of the strain without any treatment. Pectinase and cellulase significantly increased the methanol levels of the sugar cane spirits. The results showed that there was linear relationship between glycine (concentration within 0∼0.9 g/L) and methanol in sugar cane sprits and the linear equation was y = 104.7 × -4.79 with the conversion rate of glycine conversion to methanol as 24.56%. CONCLUSION: Mutagenesis of UV coupled with DES is an efficient way to generate a mutant of S. cerevisiae with lower methanol content. Also, it is necessary to control the additions of pectinase, cellulase and glycine in the fermentation medium, and other unknown ways to generate methanol metabolic pathway in yeasts may need further study.

Application of fluorescently labeled tracer technique for detection of natural active macromolecules in Chinese medicine.

Active substances in traditional Chinese Medicine (TCM) contain not only a variety of small molecules, but also many other macromolecules (TCMMs), such as proteins, peptides and polysaccharides. Active TCMM can achieve good therapeutic effects by regulating the body's overall function with lower side effects. This review summarized the literatures published in recent years on the application of fluorescently labeled tracer technique for detection of natural active macromolecules in TCM. Classified by fluorescent markers, applications of fluorescein, rhodamine, and quantum dots (QDs) in TCMM active tracer are reviewed, and the methods and principles of TCMM fluorescent marker are illustrated. Studies on active TCMMs and their action mechanism are quite difficult due to a multitarget, multicomponent, and multipath system of TCM. However, the development of fluorescently labeled active tracer technique (FLATT) provides this research with new tools. Traditional fluorescent markers have many deficiencies, such as easily quenched, short luminous cycle, and intrinsic toxicity. Relatively, FLATT has many obvious advantages, and its application in TCMM is still at the early stage. In order to improve the overall level of fluorescence labeling in TCMM active tracer, the improvement on FLATT's detection sensitivity and biological affinity is urgent and critical to allow study of these interesting molecules.

Ultrasound-enhanced and microwave-assisted extraction of lipid from Dunaliella tertiolecta and fatty acid profile analysis.

Microalgal lipid is considered as a potential biodiesel resource due to its advantages compared to other bioresources. The production of biofuel from microalgae includes several stages like microalgae cultivation, biomass harvest, biomass treatment, lipid extraction, and the ultimate biodiesel synthesis. Lipid extraction is closely associated with the productivity and cost of energy production. In the present study, lipid of green algae Dunaliella tertiolecta was extracted by chemical agents with involvement of ultrasound and microwave. The optimization of experimental conditions was carried out by response surface methodology and orthogonal test design. Using the ultrasonic technique, an extraction rate of 45.94% was obtained under the optimum conditions of ultrasonic power 370 W, extraction time 5 min and liquid/solid ratio 125 mL/g. The extraction rate of 57.02% was obtained by the means of microwave assistance under the optimized conditions of extraction time 160 s, microwave power 490 W and liquid/solid ratio 100 mL/g. The comparison of the two results indicated microwave was more effective than ultrasound in extracting process. When the two techniques were utilized in combination, the optimized condition was ultrasonic power 320 W, ultrasonic time 4 min, microwave power 280 W, microwave time 120 s and liquid/solid ratio 100 mL/g, and the extraction rate was 49.97%.

Sedative and hypnotic effects of Polygala tenuifolia willd. saponins on insomnia mice and their targets.

ETHNOPHARMACOLOGICAL RELEVANCE: Polygala tenuifolia Willd. has been widely used in the treatment of cancer, forgetfulness, depression and other diseases. AIM OF REVIEW: The purpose of this study was to investigate the sleep-enhancing effect and mechanism of P. tenuifolia saponins (PTS). MATERIALS AND METHODS: The total saponin (YZ-I) and purified saponin (YZ-II) fractions were extracted and ICR mice model of insomnia was established by p-chlorophenylalanine (PCPA) induction to observe anxiety and depression behaviors. Effects of YZ-I and YZ-II on the levels of neurotransmitters, hormones, and inflammation cytokines were detected by ELISA, RT-qPCR and western blotting. RESULTS: The results showed that YZ-I and YZ-II reduced the immobility time of mice and prolonged the sleep time of mice and significantly increased the concentrations of 5-HT, NE, PGD2, IL-1ß and TNF-α. YZ-I and YZ-II regulated GABAARα2, GABAARα3, GAD65/67, 5-HT1A and 5-HT2A, while regulated the levels of inflammatory cytokines such as DPR, PGD2, iNOS and TNF-α to exert sedative and hypnotic effects. CONCLUSION: PTS are mainly achieved sedative and hypnotic effects by altering serotonergic, GABAergic and immune systems, but the effects and mechanisms of action of YZ-I were different from YZ-II.

Sedative and hypnotic effects of the saponins from a traditional edible plant Liriope spicata Lour. in PCPA-induced insomnia mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Liriope spicata Lour., a species listed in the catalogue of 'Medicinal and Edible Homologous Species', is traditionally used for the treatment of fatigue, restlessness, insomnia and constipation. AIM OF THE STUDY: This study is aimed to evaluate the sedative and hypnotic effect of the saponins from a natural plant L. spicata Lour. in vivo. MATERIALS AND METHODS: The total saponin (LSTS) and purified saponin (LSPS) were extracted from L. spicata, followed by a thorough analysis of their major components using the HPLC-MS. Subsequently, the therapeutic efficacy of LSTS and LSPS was evaluated by the improvement of anxiety and depression behaviors of the PCPA-induced mice. RESULTS: LSTS and LSPS exhibited similar saponin compositions but differ in their composition ratios, with liriopesides-type saponins accounting for a larger proportion in LSTS. Studies demonstrated that both LSTS and LSPS can extend sleep duration and immobility time, while reducing sleep latency in PCPA-induced mice. However, there was no significant difference in weight change among the various mice groups. Elisa results indicated that the LSTS and LSPS could decrease levels of NE, DA, IL-6, and elevate the levels of 5-HT, NO, PGD2 and TNF-α in mice plasma. LSTS enhanced the expression of neurotransmitter receptors, while LSPS exhibited a more pronounced effect in regulating the expression of inflammatory factors. In conclusion, the saponins derived from L. spicata might hold promise as ingredients for developing health foods with sedative and hypnotic effects, potentially related to the modulation of serotonergic and GABAAergic neuron expression, as well as immunomodulatory process.