Effect of rosmarinic acid and carnosic acid on AGEs formation in vitro

This work aimed to investigate the effect of the two main components of rosemary extracts, namely rosmarinic acid (RA) and carnosic acid (CA), on the formation of advanced glycation end-products (AGEs) in vitro. In the bovine serum albumin (BSA)/glucose model, addition of RA and CA at 400μg/mL inhibited fluorescent AGEs by more than 90%, and carboxymethyl lysine (CML) and carboxyethyl lysine (CEL) by 82.7% and 75.2%, and 71.4% and 64.2%, respectively. Moreover, the addition of RA and CA at 400μg/mL inhibited fluorescent AGEs by more than 90% both in the BSA/glyoxal (GO) and BSA/methylglyoxal (MGO) models, the formation of CML by 64.9% and 53.9% in BSA/GO model, and CEL by 28.9% and 24.3% in BSA/MGO model, respectively. RA and CA also significantly decreased the concentration of MGO and protein carbonylation.

The 2-oxoglutarate-dependent dioxygenase superfamily participates in tanshinone production in Salvia miltiorrhiza

Highly oxidized tanshinones are pharmacological ingredients extracted from the medicinal model plant Salvia miltiorrhiza and are mainly used to treat cardiovascular diseases. Previous studies have confirmed that cytochrome P450 mono-oxygenases (CYP450s) have a key function in the biosynthesis of tanshinones; however, no solid evidence links oxidation to the 2-oxoglutarate-dependent dioxygenase (2OGD) superfamily. Here, we identified 132 members of the DOXB and DOXC subfamilies of 2OGD by scanning the 2OG-FeII Oxy domain using a genome-wide strategy in S. miltiorrhiza. The DOXC class was phylogenetically divided into twelve clades. Combining phylogenetic relationships, differential expression and co-expression from various organs and tissues revealed that two 2OGDs were directly related to flavonoid metabolism, and that 13 2OGDs from different clades were predicted to be involved in tanshinone biosynthesis. Based on this insight into tanshinone production, we experimentally detected significant decreases in miltirone, cryptotanshinone, and tanshinone IIA (0.16-, 0.56-, and 0.56-fold, respectively) in 2OGD5 RNAi transgenic lines relative to the control lines using a metabonomics analysis. 2OGD5 was found to play a crucial role in the downstream biosynthesis of tanshinones following the hydroxylation of CYPs. Our results highlight the evolution and diversification of 2OGD superfamily members and suggest that they contribute to the complexity of tanshinone metabolites.

The terpene synthase gene family in Tripterygium wilfordii harbors a labdane-type diterpene synthase among the monoterpene synthase TPS-b subfamily

Tripterygium wilfordii (Celastraceae) is a medicinal plant with anti-inflammatory and immunosuppressive properties. Identification of a vast array of unusual sesquiterpenoids, diterpenoids and triterpenoids in T. wilfordii has spurred investigations of their pharmacological properties. The tri-epoxide lactone triptolide was the first of many diterpenoids identified, attracting interest due to the spectrum of bioactivities. To probe the genetic underpinning of diterpenoid diversity, an expansion of the class II diterpene synthase (diTPS) family was recently identified in a leaf transcriptome. Following detection of triptolide and simple diterpene scaffolds in the root, we sequenced and mined the root transcriptome. This allowed identification of the root-specific complement of TPSs and an expansion in the class I diTPS family. Functional characterization of the class II diTPSs established their activities in the formation of four C-20 diphosphate intermediates, precursors of both generalized and specialized metabolism and a novel scaffold for Celastraceae. Functional pairs of the class I and II enzymes resulted in formation of three scaffolds, accounting for some of the terpenoid diversity found in T. wilfordii. The absence of activity-forming abietane-type diterpenes encouraged further testing of TPSs outside the canonical class I diTPS family. TwTPS27, close relative of mono-TPSs, was found to couple with TwTPS9, converting normal-copalyl diphosphate to miltiradiene. The phylogenetic distance to established diTPSs indicates neo-functionalization of TwTPS27 into a diTPS, a function not previously observed in the TPS-b subfamily. This example of evolutionary convergence expands the functionality of TPSs in the TPS-b family and may contribute miltiradiene to the diterpenoids of T. wilfordii.

Ectopic Expression of DREB Transcription Factor, AtDREB1A, Confers Tolerance to Drought in Transgenic Salvia miltiorrhiza

Drought decreases crop productivity more than any other type of environmental stress. Transcription factors (TFs) play crucial roles in regulating plant abiotic stress responses. The Arabidopsis thaliana gene DREB1A/CBF3, encoding a stress-inducible TF, was introduced into Salvia miltiorrhiza Ectopic expression of AtDREB1A resulted in increased drought tolerance, and transgenic lines had higher relative water content and Chl content, and exhibited an increased photosynthetic rate when subjected to drought stress. AtDREB1A transgenic plants generally displayed lower malondialdehyde (MDA), but higher superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activities under drought stress. In particular, plants with ectopic AtDREB1A expression under the control of the stress-induced RD29A promoter exhibited more tolerance to drought compared with p35S::AtDREB1A transgenic plants, without growth inhibition or phenotypic aberrations. Differential gene expression profiling of wild-type and pRD29A::AtDREB1A transgenic plants following drought stress revealed that the expression levels of various genes associated with the stress response, photosynthesis, signaling, carbohydrate metabolism and protein protection were substantially higher in transgenic plants. In addition, the amount of salvianolic acids and tanshinones was significantly elevated in AtDREB1A transgenic S. miltiorrhiza roots, and most of the genes in the related biosynthetic pathways were up-regulated. Together, these results demonstrated that inducing the expression of a TF can effectively regulate multiple genes in the stress response pathways and significantly improve the resistance of plants to abiotic stresses. Our results also suggest that genetic manipulation of a TF can improve production of valuable secondary metabolites by regulating genes in associated pathways.

Cytochrome P450 promiscuity leads to a bifurcating biosynthetic pathway for tanshinones

Cytochromes P450 (CYPs) play a key role in generating the structural diversity of terpenoids, the largest group of plant natural products. However, functional characterization of CYPs has been challenging because of the expansive families found in plant genomes, diverse reactivity and inaccessibility of their substrates and products. Here we present the characterization of two CYPs, CYP76AH3 and CYP76AK1, which act sequentially to form a bifurcating pathway for the biosynthesis of tanshinones, the oxygenated diterpenoids from the Chinese medicinal plant Danshen (Salvia miltiorrhiza). These CYPs had similar transcription profiles to that of the known gene responsible for tanshinone production in elicited Danshen hairy roots. Biochemical and RNA interference studies demonstrated that both CYPs are promiscuous. CYP76AH3 oxidizes ferruginol at two different carbon centers, and CYP76AK1 hydroxylates C-20 of two of the resulting intermediates. Together, these convert ferruginol into 11,20-dihydroxy ferruginol and 11,20-dihydroxy sugiol en route to tanshinones. Moreover, we demonstrated the utility of these CYPs by engineering yeast for heterologous production of six oxygenated diterpenoids, which in turn enabled structural characterization of three novel compounds produced by CYP-mediated oxidation. Our results highlight the incorporation of multiple CYPs into diterpenoid metabolic engineering, and a continuing trend of CYP promiscuity generating complex networks in terpenoid biosynthesis.

Synergistic effects of ultraviolet-B and methyl jasmonate on tanshinone biosynthesis in Salvia miltiorrhiza hairy roots

Tanshinones are major bioactive diterpenoids of Salvia miltiorrhiza roots used for the treatment of cardiocerebral diseases. To develop effective elicitation and bioprocess strategies for the enhanced production of tanshinones, ultraviolet-B (UV-B) irradiation and methyl jasmonate (MeJA) elicitation were applied alone or in combination respectively in S. miltiorrhiza hairy root cultures. Our results showed 40-min UV-B irradiation at 40μW/cm(2) stimulated tanshinone production without any suppression of root growth, suggesting a new effective elicitor to S. miltiorrhiza hairy root cultures for tanshinone production. Moreover, the combined treatment of UV-B irradiation and MeJA exhibited synergistic effects on the expression levels of 3-hydroxy-3-methylglutaryl-CoA reductase (SmHMGR) and geranylgeranyl diphosphate synthase (SmGGPPS) genes in the tanshinone biosynthetic pathway. When hairy roots of 18-day-old cultures were exposed to the combined elicitation for 9days, the maximum production of tanshinone reached to 28.21mg/L, a 4.9-fold increase over the control. The combined elicitation of UV-B and MeJA was firstly used to stimulate the production of biologically important secondary metabolites in hairy root cultures.

Establishment of Salvia castanea Diels f. tomentosa Stib. hairy root cultures and the promotion of tanshinone accumulation and gene expression with Ag⁺, methyl jasmonate, and yeast extract elicitation

Salvia castanea Diels f. tomentosa Stib. is an endemic medicinal plant distributed in China, and the notably high content of tanshinone IIA in the root is proven effective for the therapy of heart diseases. Hairy root induction of this Salvia species was inoculated with Agrobacterium rhizogenes strain ATCC 15834. Transformed hairy root was cultured in 6,7-V liquid medium for growth kinetics assessment and elicitation. An S curve was present in the hairy root cultures based on the fresh and dry weights with an interval of 3 days. An optimum concentration of the applied elicitors (15 μM Ag(+), 200 μM methyl jasmonate, and 200 mg l(-1) yeast extract elicitor) benefitted both the growth status and tanshinone accumulation in the hairy root cultures. Tanshinone IIA contents were mostly stimulated 1.8-fold and 1.99-fold compared with the control by Ag(+) and methyl jasmonate elicitation, respectively. Yeast extract dramatically enhanced dry mass accumulation, while it promoted cryptotanshinone content of 2.84 ± 0.33 mg g(-1) dry weight at most in the hairy root cultures. Selected elicitors diversely influenced tanshinone accumulation in the time courses of hairy root cultures within 7 days. Furthermore, transcripts of selected genes in the tanshinone biosynthetic pathway were remarkably upregulated with elicitation. Yeast extract elicitor heightened 13.9-fold of isopentenyl diphosphate isomerase expression level at 12 h, while it increased 16.7-fold of geranylgeranyl diphosphate synthase transcript at 24 h compared with that of the control, which was more effective than Ag(+) and methyl jasmonate. This study provided a convenient hairy root culture system of S. castanea Diels f. tomentosa Stib. for tanshinone production for the first time.

Influence of sodium salicylate on rosmarinic acid, carnosol and carnosic acid accumulation by Salvia officinalis L. shoots grown in vitro

OBJECTIVES

To evaluate sodium salicylate (NaSA) as an elicitor of rosmarinic acid (RA) and phenolic diterpenes, carnosol (C) and carnosic acid (CA) production, in a culture of Salvia officinalis shoots.

RESULTS

In sage shoots grown in vitro, 28 polyphenolic compounds (phenolic acids, flavonoids, and phenolic diterpenes) were identified. In shoots treated for 1 week with increasing NaSA concentrations, the content of C increased from 2.3 in control to 5.7 mg g(-1) DW in shoots treated with 500 µM NaSA. In shoots that were recovered on basal medium for 3 weeks, the maximal amount of C (14 mg/g(-1) DW) was with 150 µM NaSA treatment. In treated and recovered shoots, the increase in C was accompanied with a decrease in CA, resulting in 1.9-fold increase in the C/CA ratio. Accumulation of RA was not affected by the NaSA treatment. However, elicitation by NaSA was accompanied with growth retardation.

CONCLUSIONS

NaSA can improve C production in sage shoot culture, probably by stimulating the conversion of CA to C.

Nrf2 activators modulate oxidative stress responses and bioenergetic profiles of human retinal epithelial cells cultured in normal or high glucose conditions

Retinal pigment epithelial cells exert an important supporting role in the eye and develop adaptive responses to oxidative stress or high glucose levels, as observed during diabetes. Endogenous antioxidant defences are mainly regulated by Nrf2, a transcription factor that is activated by naturally-derived and electrophilic compounds. Here we investigated the effect of the Nrf2 activators dimethylfumarate (DMF) and carnosol on antioxidant pathways, oxygen consumption rate and wound healing in human retinal pigment epithelial cells (ARPE-19) cultured in medium containing normal (NG, 5mM) or high (HG, 25 mM) glucose levels. We also assessed wound healing using an in vivo corneal epithelial injury model. We found that Nrf2 nuclear translocation and heme oxygenase activity increased in ARPE cells treated with 10 μM DMF or carnosol irrespective of glucose culture conditions. However, HG rendered retinal cells more sensitive to regulators of glutathione synthesis or inhibition and caused a decrease of both cellular and mitochondrial reactive oxygen species. Culture in HG also reduced ATP production and mitochondrial function as measured with the Seahorse XF analyzer and electron microscopy analysis revealed morphologically damaged mitochondria. Acute treatment with DMF or carnosol did not restore mitochondrial function in HG cells; conversely, the compounds reduced cellular maximal respiratory and reserve capacity, which were completely prevented by N-acetylcysteine thus suggesting the involvement of thiols in this effect. Interestingly, the scratch assay showed that wound closure was faster in cells cultured in HG than NG and was accelerated by carnosol. This effect was reversed by an inhibitor of heme oxygenase activity. Moreover, topical application of carnosol to the cornea of diabetic rats significantly accelerated wound healing. In summary, these data indicate that culture of retinal epithelial cells in HG does not affect the activation of the Nrf2/heme oxygenase axis but influences other crucial oxidative and mitochondrial-dependent cellular functions. The additional effect on wound closure suggests that results obtained in in vitro experimental settings need to be carefully evaluated in the context of the glucose concentrations used in cell culture.

Full-length transcriptome sequences and splice variants obtained by a combination of sequencing platforms applied to different root tissues of Salvia miltiorrhiza and tanshinone biosynthesis

Danshen, Salvia miltiorrhiza Bunge, is one of the most widely used herbs in traditional Chinese medicine, wherein its rhizome/roots are particularly valued. The corresponding bioactive components include the tanshinone diterpenoids, the biosynthesis of which is a subject of considerable interest. Previous investigations of the S. miltiorrhiza transcriptome have relied on short-read next-generation sequencing (NGS) technology, and the vast majority of the resulting isotigs do not represent full-length cDNA sequences. Moreover, these efforts have been targeted at either whole plants or hairy root cultures. Here, we demonstrate that the tanshinone pigments are produced and accumulate in the root periderm, and apply a combination of NGS and single-molecule real-time (SMRT) sequencing to various root tissues, particularly including the periderm, to provide a more complete view of the S. miltiorrhiza transcriptome, with further insight into tanshinone biosynthesis as well. In addition, the use of SMRT long-read sequencing offered the ability to examine alternative splicing, which was found to occur in approximately 40% of the detected gene loci, including several involved in isoprenoid/terpenoid metabolism.

HPLC-SPE-NMR characterization of major metabolites in Salvia fruticosa Mill. extract with antifungal potential: relevance of carnosic acid, carnosol, and hispidulin

Plant pathogenic fungi are considered of significant economic importance for adversely affecting both quantitatively and qualitatively fresh and processed produce. Extracts of Salvia fruticosa were initially screened for their antifungal activity, and the ethyl acetate fraction, being the most active, was further analyzed using HPLC-SPE-NMR hyphenation. The methoxylated flavones hispidulin, salvigenin, and cirsimaritin and the diterpenes carnosic acid, carnosol, and 12-methoxycarnosic acid were identified as the major components of the extract. In addition, the concentration levels of all identified components were determined using q-NMR. The antifungal activity of the crude extract and selected phytochemicals was estimated against the fungal species Aspergillus tubingensis, Botrytis cinerea, and Penicillium digitatum. The estimated MIC and MFC values of the ethyl acetate extract of S. fruticosa, as well as three of its major constituents, carnosic acid, carnosol, and hispidulin, support their antifungal activity, especially against B. cinerea and P. digitatum, suggesting their potential use in food and agricultural systems.

The novolactone natural product disrupts the allosteric regulation of Hsp70

The highly conserved 70 kDa heat shock proteins (Hsp70) play an integral role in proteostasis such that dysregulation has been implicated in numerous diseases. Elucidating the precise role of Hsp70 family members in the cellular context, however, has been hampered by the redundancy and intricate regulation of the chaperone network, and relatively few selective and potent tools. We have characterized a natural product, novolactone, that targets cytosolic and ER-localized isoforms of Hsp70 through a highly conserved covalent interaction at the interface between the substrate-binding and ATPase domains. Biochemical and structural analyses indicate that novolactone disrupts interdomain communication by allosterically inducing a conformational change in the Hsp70 protein to block ATP-induced substrate release and inhibit refolding activities. Thus, novolactone is a valuable tool for exploring the requirements of Hsp70 chaperones in diverse cellular contexts.

Spaceflight environment-induced variation in root yield and active constituents of Salvia miltiorrhiza

Salvia miltiorrhiza is a significant source of bioactive compounds providing human health effects. Here, we surveyed root yield and the active constituents' divergences of second generation S. miltiorrhiza (SP2) responding to a spaceflight environment. High-performance liquid chromatography was conducted for the comprehensive constituents' characterizations of 28 SP2 lines (224 individuals) and the ground control (eight individuals). The results showed that the mean fresh and dry weight of roots ranged from 116 to 172 g and 25 to 119 g, respectively, in SP2 lines. In addition, the mean contents of four tanshinone compounds (tanshinone I, tanshinone IIA, cryptotanshinone, and dihydrotanshinone I) of 28 SP2 lines varied from 0.32 to 1.04 mg · g(-1), 0.47 to 2.39 mg · g(-1), 0.25 to 1.60 mg · g(-1), and 0.53 to 1.67 mg · g(-1), respectively. Except for salvianolic acid B, which varied drastically from 72 % to 201 % of the ground control treatment, the other six phenolic acid contents of the 28 SP2 lines all increased after spaceflight. Principal component analysis was performed to obtain an overview of the distribution of all samples, and score plots clearly separated the SP2 accessions from ground controls. Moreover, a positive relationship was observed between tanshinone I and tanshinone IIA (r = 0.790, p < 0.01), and rosmarinic acid was positively correlated with salvianolic acid B (r = 0.728, p < 0.01). In conclusion, this study demonstrated that a spaceflight environment induced SP2 accessions remarkably in the variation of root yield and active constituent content.

The accumulation pattern of ferruginol in the heartwood-forming Cryptomeria japonica xylem as determined by time-of-flight secondary ion mass spectrometry and quantity analysis

BACKGROUND AND AIMS

Heartwood formation is a unique phenomenon of tree species. Although the accumulation of heartwood substances is a well-known feature of the process, the accumulation mechanism remains unclear. The aim of this study was to determine the accumulation process of ferruginol, a predominant heartwood substance of Cryptomeria japonica, in heartwood-forming xylem.

METHODS

The radial accumulation pattern of ferruginol was examined from sapwood and through the intermediate wood to the heartwood by direct mapping using time-of-flight secondary ion mass spectrometry (TOF-SIMS). The data were compared with quantitative results obtained from a novel method of gas chromatography analysis using laser microdissection sampling and with water distribution obtained from cryo-scanning electron microscopy.

KEY RESULTS

Ferruginol initially accumulated in the middle of the intermediate wood, in the earlywood near the annual ring boundary. It accumulated throughout the entire earlywood in the inner intermediate wood, and in both the earlywood and the latewood in the heartwood. The process of ferruginol accumulation continued for more than eight annual rings. Ferruginol concentration peaked at the border between the intermediate wood and heartwood, while the concentration was less in the latewood compared with the earlywood in each annual ring. Ferruginol tended to accumulate around the ray parenchyma cells. In addition, at the border between the intermediate wood and heartwood, the accumulation was higher in areas without water than in areas with water.

CONCLUSIONS

TOF-SIMS clearly revealed ferruginol distribution at the cellular level. Ferruginol accumulation begins in the middle of intermediate wood, initially in the earlywood near the annual ring boundary, then throughout the entire earlywood, and finally across to the whole annual ring in the heartwood. The heterogeneous timing of ferruginol accumulation could be related to the distribution of ray parenchyma cells and/or water in the heartwood-forming xylem.

[Effect of Glomus versiforme and Trichoderma harzianum on growth and quality of Salvia miltiorrhiza]

The present study aimed to investigate the effect of Glomus versiforme and Trichodema harzianum on the growth and quality of Salvia miltiorrhiza continuous cropping under field conditions. The field plot experiment was conducted, these active components in the plant were analyzed by HPLC, the root diseases incidence rate of S. miltiorrhiza determined by observation and counting, and relative parameters were measured. The data was statistically processed. The result showed that inoculation of G. versiforme and combined inoculation of G. versiforme with T. harzianum significantly decreased the root diseases incidence rate of S. miltiorrhiza, and combined inoculation of G. versiforme with T. harzianum was better than other treatments. All treatments improved accumulation of active ingredients in root. Inoculation of G. versiforme and combined inoculation of G. versiforme with T. harzianum significantly increased the content of salvianolic acid B and cryptotanshinone of root (P < 0.05), Inoculation of G. versiforme, T. harzianum and combined inoculation of G. versiforme with T. harzianum significantly enhanced the content of tanshinone I and tanshinone II(A) of the root (P < 0.05). It may conclude that inoculation of G. versiforme and combined inoculation of G. versiforme with T. harzianum can effectively reduce the root diseases incidence of continuous cropping S. miltiorrhiza, and improve the quality of S. miltiorrhiza.

Manoyl oxide (13R), the biosynthetic precursor of forskolin, is synthesized in specialized root cork cells in Coleus forskohlii

Forskolin, a complex labdane diterpenoid found in the root of Coleus forskohlii (Lamiaceae), has received attention for its broad range of pharmacological activities, yet the biosynthesis has not been elucidated. We detected forskolin in the root cork of C. forskohlii in a specialized cell type containing characteristic structures with histochemical properties consistent with oil bodies. Organelle purification and chemical analysis confirmed the localization of forskolin and of its simplest diterpene precursor backbone, (13R) manoyl oxide, to the oil bodies. The labdane diterpene backbone is typically synthesized by two successive reactions catalyzed by two distinct classes of diterpene synthases. We have recently described the identification of a small gene family of diterpene synthase candidates (CfTPSs) in C. forskohlii. Here, we report the functional characterization of four CfTPSs using in vitro and in planta assays. CfTPS2, which synthesizes the intermediate copal-8-ol diphosphate, in combination with CfTPS3 resulted in the stereospecific formation of (13R) manoyl oxide, while the combination of CfTPS1 and CfTPS3 or CfTPS4 led to formation of miltiradiene, precursor of abietane diterpenoids in C. forskohlii. Expression profiling and phylogenetic analysis of the CfTPS family further support the functional diversification and distinct roles of the individual diterpene synthases and the involvement of CfTPS1 to CfTPS4 in specialized metabolism and of CfTPS14 and CfTPS15 in general metabolism. Our findings pave the way toward the discovery of the remaining components of the pathway to forskolin, likely localized in this specialized cell type, and support a role of oil bodies as storage organelles for lipophilic bioactive metabolites.

[Application of synthetic biology to sustainable utilization of Chinese materia medica resources]

Bioactive natural products are the material bases of Chinese materia medica resources. With successful applications of synthetic biology strategies to the researches and productions of taxol, artemisinin and tanshinone, etc, the potential ability of synthetic biology in the sustainable utilization of Chinese materia medica resources has been attracted by many researchers. This paper reviews the development of synthetic biology, the opportunities of sustainable utilization of Chinese materia medica resources, and the progress of synthetic biology applied to the researches of bioactive natural products. Furthermore, this paper also analyzes how to apply synthetic biology to sustainable utilization of Chinese materia medica resources and what the crucial factors are. Production of bioactive natural products with synthetic biology strategies will become a significant approach for the sustainable utilization of Chinese materia medica resources.

[Effects on Salvia miltiorrhiza hairy roots of tanshinones content accumulation after treated with fosmidomycin]

Fosmidomycin (100 micromol x L(-1)) which is the effective inhibitor of DXR, key enzyme in terpenoid MEP pathway, was used to treat with hairy roots of Salvia miltiorrhiza. The treated roots were harvested at 2, 4, 6, 8, 10, 16 and 21 d, mRNA level of SmDXR and tanshinone content in treated and negative control groups were detected. Results found that, after treated with fosmidomycin, color of S. miltiorrhiza hairy roots grew pale gradually comparing with controls; mRNA level of SmDXR in hairy roots varied as a shape of parabolic and the highest value achieved at the sixth day after treatment, then it decreased gradually; Content of four kinds of tanshinones were detected. Among of the four kinds of tanshinones, Tanshinone I content changed relatively little, while content of dihydrotanshinone I, cryptotanshinone and tanshinone II (A) decreased gradually in 21 days. The content of total tanshinones in NC groups was 5, 63 times more than FOS-treated roots in the 21th day. The previous results showed that SmDXR played an important role in the accumulation of tanshinone content in MEP pathway. Once the mRNA level of SmDXR was suppressed, the accumulation of secondary metabolites will be significantly affected.

Effects of combined elicitors on tanshinone metabolic profiling and SmCPS expression in Salvia miltiorrhiza hairy root cultures

Tanshinones are abietane-type norditerpenoid quinone natural products found in a well-known traditional Chinese medicinal herb, Salvia miltiorrhiza Bunge. The copalyl diphosphate synthase of S. miltiorrhiza (SmCPS) is the key enzyme in the first step for transformation of geranylgeranyl diphosphate (GGPP) into miltiradiene, which has recently been identified as the precursor of tanshinones. Based on previous gene-to-metabolite network, this study examined the influences of various combined elicitors on the expression of SmCPS and production of tanshinones in S. miltiorrhiza hairy root cultures. Combined elicitors were composed of three classes of elicitors, a heavy metal ion (Ag⁺), a polysaccharide (yeast extract, YE), and a plant response-signalling compound (methyl jasmonate, MJ). YE + Ag⁺, Ag⁺ + MJ, YE + MJ, and YE + Ag⁺ + MJ were the combinations we tested. The effect of elicitors on the SmCPS expression level was detected by quantitative real-time PCR (qRT-PCR), and the tanshinones accumulation responses to elicitation were analysed by Ultra Performance Liquid Chromatography (UPLC) metabolite profiling. Of these combined elicitors, the expression of SmCPS was significantly enhanced by elicitation, especially at 24 h and 36 h. Of four tanshinones detected, the contents of cryptotanshinone and dihydrotanshinone I were enhanced by treatment with YE + Ag⁺, Ag⁺ + MJ, and YE + Ag⁺ + MJ. Our results indicate that appropriate combined elicitors can enhance tanshinones production in hairy root cultures.

Tanshinones inhibit amyloid aggregation by amyloid-β peptide, disaggregate amyloid fibrils, and protect cultured cells

The misfolding and aggregation of amyloid-β (Aβ) peptides into amyloid fibrils is regarded as one of the causative events in the pathogenesis of Alzheimer's disease (AD). Tanshinones extracted from Chinese herb Danshen (Salvia Miltiorrhiza Bunge) were traditionally used as anti-inflammation and cerebrovascular drugs due to their antioxidation and antiacetylcholinesterase effects. A number of studies have suggested that tanshinones could protect neuronal cells. In this work, we examine the inhibitory activity of tanshinone I (TS1) and tanshinone IIA (TS2), the two major components in the Danshen herb, on the aggregation and toxicity of Aβ1-42 using atomic force microscopy (AFM), thioflavin-T (ThT) fluorescence assay, cell viability assay, and molecular dynamics (MD) simulations. AFM and ThT results show that both TS1 and TS2 exhibit different inhibitory abilities to prevent unseeded amyloid fibril formation and to disaggregate preformed amyloid fibrils, in which TS1 shows better inhibitory potency than TS2. Live/dead assay further confirms that introduction of a very small amount of tanshinones enables protection of cultured SH-SY5Y cells against Aβ-induced cell toxicity. Comparative MD simulation results reveal a general tanshinone binding mode to prevent Aβ peptide association, showing that both TS1 and TS2 preferentially bind to a hydrophobic β-sheet groove formed by the C-terminal residues of I31-M35 and M35-V39 and several aromatic residues. Meanwhile, the differences in binding distribution, residues, sites, population, and affinity between TS1-Aβ and TS2-Aβ systems also interpret different inhibitory effects on Aβ aggregation as observed by in vitro experiments. More importantly, due to nonspecific binding mode of tanshinones, it is expected that tanshinones would have a general inhibitory efficacy of a wide range of amyloid peptides. These findings suggest that tanshinones, particularly TS1 compound, offer promising lead compounds with dual protective role in anti-inflammation and antiaggregation for further development of Aβ inhibitors to prevent and disaggregate amyloid formation.

[Effects of ABA on tanshinones accumulation of Salvia miltiorrhiza hairy root]

OBJECTIVE

To study the effects of Abscisic Acid (ABA) on the accumulation of tanshinones in suspension cultures of Salvia miltiorrhiza hairy roots.

METHODS

After suspension culture of Salvia miltiorrhiza hairy roots induced by agrobacterium rhizogenes ATCC15834 for 20 days, the ABA was added into suspension cultures, the contents of tanshinones (including tanshinone I , cryptotanshinone, dihydrotanshinon I and tanshinone II A) were detected by HPLC after 7 days.

RESULTS

The growth of Salvia miltiorrhiza hairy roots was inhibited by ABA. 20 micromol/L ABA treatment had no significant effect. The dry weight of Salvia miltiorrhiza hairy roots of other ABA treatments reduced to 65.2% ,71% and 56.5% of the control, respectively. Different levels of ABA could significantly increased the yields of four tanshinones in Salvia miltiorrhiza hairy roots. The yields of tanshinone I , cryptotanshinone, dihydrotanshinon I and tanshinone II A were significantly increased to 5.4, 9. 5, 1.5 and 1.8 times that of the control group after dealing with 210 micromol/ L ABA.

CONCLUSION

ABA can stimulate the accumulation of tanshinones in Salvia miltiorrhiza hairy roots.

[Study on effective constituents extracted from fibrous roots of Salvia miltiorrhiza with degrading multi-enzymes from taishan Ganoderma lucidum]

OBJECTIVE

To study the application of degrading multi-enzymes from Ganoderma lucidum in extracting effective constituents from fibrous roots of Salvia miltiorrhiza.

METHOD

Effective constituents were extracted from fibrous roots by degrading multi-enzymes of wood fiber. The enzymatic parameters were optimized by the orthogonal design.

RESULT

The extraction efficiencies of total tanshinones and total salvianolic acids in the extracts of fibrous roots of S. miltiorrhiza was obtained using optimum enzymolysis process reached 11.923%, 12.465%, respectively, which were 62.794%, 56.086% more than that by conventional non-enzymatic hydrolysis.

CONCLUSION

Degrading multi-enzymes of wood fiber can be used to fully extract effective constituents from fibrous roots of S. miltiorrhiza, which provides a new approach for recycling wastes of traditional Chinese medicines.

[Preparation of panax notoginseng saponins-tanshinone H(A) composite method for pulmonary delivery with spray-drying method and its characterization]

OBJECTIVE

To prepare panax notoginseng saponins-tanshinone II(A) composite particles for pulmonary delivery, in order to explore a dry powder particle preparation method ensuring synchronized arrival of multiple components of traditional Chinese medicine compounds at absorption sites.

METHOD

Panax notoginseng saponins-tanshinone II(A) composite particles were prepared with spray-drying method, and characterized by scanning electron microscopy (SEM), confocal laser scanning microscope (CLSM), X-ray diffraction (XRD), infrared analysis (IR), dry laser particle size analysis, high performance liquid chromatography (HPLC) and the aerodynamic behavior was evaluated by a Next Generation Impactor (NGI).

RESULT

The dry powder particles produced had narrow particle size distribution range and good aerodynamic behavior, and could realize synchronized administration of multiple components.

CONCLUSION

The spray-drying method is used to combine traditional Chinese medicine components with different physical and chemical properties in the same particle, and product into traditional Chinese medicine compound particles in line with the requirements for pulmonary delivery.

[Cloning and induced expression analysis of 4-hydroxy-3-methyl-but-2-enyl diphosphate reductase gene (smHDR) of Salvia miltiorrhiza]

This study reported the obtainment of the full-length cDNA of Salvia miltiorrhiza hairy roots (Abbr: SmHDR, GenBank number: JX233817), via extracting Salvia miltiorrhiza hairy roots total RNA, designing specific primers according to the transcriptome data and using the RACE strategy, and then analyzed it with bioinformatics approaches. On this basis, using the real-time PCR to detect SmHDR gene expression after Ag+ induction, and testing tanshinones contents of corresponding samples by UPLC. SmHDR has 1 647 nucleotides, and an open reading frame (ORF) encoding a protein of 463 amino acid residues. The deduced protein has isoelectric point (pI) of 5.72 and a calculated molecular weight about 51.88 kD. In the secondary structure, the percentage of alpha helix, beta turn and random coil were 35.64%, 20.30% and 44.06%, respectively. Sequence alignment and phylogenetic analysis demonstrated that SmHDR had relative close relationship to the HDR of Picrorhiza kurrooa, similar to HDR from other species of plants. Real time PCR results indicated that elicitor of Ag+ stimulated the increase of mRNA expression of SmHDR. At the same time, results of ultra performance liquid chromatography (UPLC), used to examine the accumulation of diterpenoid tanshinones in hairy roots, showed that the contents of diterpenoid tanshinones in hairy roots of Salvia miltiorrhiza were increased dramatically at 12 h after treated with Ag+, and then decreased significantly. This result showed a positive correlation between the levels of mRNA expression and tanshinones accumulation in Salvia miltiorrhiza stimulated by Ag+. The content of tanshinones was gradually raised, and it had an obvious increase at 120 h. The bioinformatics analysis and gene expression indicated that SmHDR might be involved in tanshinones biosynthesis, which laid the foundation for further study of secondary metabolic regulation mechanism of tanshinones.

Ultrasound-assisted extraction of carnosic acid and rosmarinic acid using ionic liquid solution from Rosmarinus officinalis

Ionic liquid based, ultrasound-assisted extraction was successfully applied to the extraction of phenolcarboxylic acids, carnosic acid and rosmarinic acid, from Rosmarinus officinalis. Eight ionic liquids, with different cations and anions, were investigated in this work and [C(8)mim]Br was selected as the optimal solvent. Ultrasound extraction parameters, including soaking time, solid-liquid ratio, ultrasound power and time, and the number of extraction cycles, were discussed by single factor experiments and the main influence factors were optimized by response surface methodology. The proposed approach was demonstrated as having higher efficiency, shorter extraction time and as a new alternative for the extraction of carnosic acid and rosmarinic acid from R. officinalis compared with traditional reference extraction methods. Ionic liquids are considered to be green solvents, in the ultrasound-assisted extraction of key chemicals from medicinal plants, and show great potential.