Optimizing the extract yield of bioactive compounds in Valeriana officinalis root: a D-optimal design.

It is estimated that 80% of all synthetic drugs are derived from medicinal plants, and nowadays, many synthetic drugs are derived from medicinal plants. Valeriana officinalis can treat many diseases of the nervous system. A crucial aspect of valerian extract is that it inhibits the proliferation of breast cancer cells. To optimize the yield of bioactive compounds in the V. officinalis root extraction, a response surface methodology-based D-optimal design was used. To fulfill this aim, the effects of various factors such as solvent type and concentration, mixing temperature, ultrasound time, and drying method were examined. The optimal conditions for solvent percentages, mixing temperature, ultrasound time, solvent type, and drying methods were determined to be 94.88%, 25 °C, 48.95 min, methanol, and microwave, respectively, with a desirability of 0.921. The predicted valerenic acid, total phenols, total flavonoids, and antioxidant activity in V. officinalis extract were 1.19 (mg/g DW), 8.22 (mg/g DW), 5.27 (mg/g DW), and 92.64%, respectively. In optimal conditions, the extracted amounts of valerenic acid, total phenols, total flavonoids, and antioxidant activity were 2.07 mg/g DW, 7.96 mg/g DW, 5.52 mg/g DW, and 78.68%, respectively, which were consistent with the model predicted amounts (based on 95% prediction interval). This study could be useful as a model for demonstrating the efficacy of microwave drying to maximize the biochemical content of V. officinalis, as well as the antioxidant activity of the root extracts of V. officinalis on industrial scale.

Valerenic acid attenuates pathological myocardial hypertrophy by promoting the utilization of multiple substrates in the mitochondrial energy metabolism.

INTRODUCTION: Valerenic acid (VA) is a unique and biologically active component in Valeriana officinalis L., which has been reported to have a regulatory effect on the cardiovascular system. However, its therapeutic effects on pathological myocardial hypertrophy (PMH) and the underlying mechanisms are undefined. OBJECTIVES: Our study aims to elucidate how VA improves PMH, and preliminarily discuss its mechanism. METHODS: The efficacy of VA on PMH was confirmed by in vivo and in vitro experiments and the underlying mechanism was investigated by molecular dynamics (MD) simulations and specific siRNA interference. RESULTS: VA enhanced cardiomyocyte fatty acid oxidation (FAO), inhibited hyper-activated glycolysis, and improved the unbalanced pyruvate-lactate axis. VA could significantly improve impaired mitochondrial function and reduce the triglyceride (TG) in the hypertrophic myocardium while reducing the lactate (LD) content. Molecular mechanistic studies showed that VA up-regulated the expression of peroxisome proliferator-activated receptor-α (PPARα) and downstream FAO-related genes including CD36, CPT1A, EHHADH, and MCAD. VA reduced the expression of ENO1 and PDK4, the key enzymes in glycolysis. Meanwhile, VA improved the pyruvate-lactate axis and promoted the aerobic oxidation of pyruvate by inhibiting LDAH and MCT4. MD simulations confirmed that VA can bind with the F273 site of PPARα, which proposes VA as a potential activator of the PPARα. CONCLUSION: Our results demonstrated that VA might be a potent activator for the PPARα-mediated pathway. VA directly targets the PPARα and subsequently promotes energy metabolism to attenuate PMH, which can be applied as a potentially effective drug for the treatment of HF.

Transplacental passage of hyperforin, hypericin, and valerenic acid.

Safe medications for mild mental diseases in pregnancy are needed. Phytomedicines from St. John's wort and valerian are valid candidates, but safety data in pregnancy are lacking. The transplacental transport of hyperforin and hypericin (from St. John's wort), and valerenic acid (from valerian) was evaluated using the ex vivo cotyledon perfusion model (4 h perfusions, term placentae) and, in part, the in vitro Transwell assay with BeWo b30 cells. Antipyrine was used for comparison in both models. U(H)PLC-MS/MS bioanalytical methods were developed to quantify the compounds. Perfusion data obtained with term placentae showed that only minor amounts of hyperforin passed into the fetal circuit, while hypericin did not cross the placental barrier and valerenic acid equilibrated between the maternal and fetal compartments. None of the investigated compounds affected metabolic, functional, and histopathological parameters of the placenta during the perfusion experiments. Data from the Transwell model suggested that valerenic acid does not cross the placental cell layer. Taken together, our data suggest that throughout the pregnancy the potential fetal exposure to hypericin and hyperforin - but not to valerenic acid - is likely to be minimal.

Intestinal permeability and gut microbiota interactions of pharmacologically active compounds in valerian and St. John's wort.

Phytomedicines such as valerian and St. John's wort are widely used for the treatment of sleeping disorders, anxiety and mild depression. They are perceived as safe alternatives to synthetic drugs, but limited information is available on the intestinal absorption and interaction with human intestinal microbiota of pharmacologically relevant constituents valerenic acid in valerian, and hyperforin and hypericin in St. John's wort. The intestinal permeability of these compounds and the antidepressant and anxiolytic drugs citalopram and diazepam was investigated in the Caco-2 cell model with bidirectional transport experiments. In addition, interaction of compounds and herbal extracts with intestinal microbiota was evaluated in artificial human gut microbiota. Microbiota-mediated metabolisation of compounds was assessed, and bacterial viability and short-chain fatty acids (SCFA) production were measured in the presence of compounds or herbal extracts. Valerenic acid and hyperforin were highly permeable in Caco-2 cell monolayers. Hypericin showed low-to-moderate permeability. An active transport process was potentially involved in the transfer of valerenic acid. Hyperforin and hypericin were mainly transported through passive transcellular diffusion. All compounds were not metabolized over 24 h in the artificial gut microbiota. Microbial SCFA production and bacterial viability was not substantially impaired nor promoted by exposure to the compounds or herbal extracts.

The Human Host Defense Peptide LL-37 Overexpressed in Lung Cell Lines by Methanolic Extract of Valeriana officinalis

Abstract The present study investigated the effects of valerian methanolic extract and valerenic acid on the expression of LL-37 gene and protein in A549 and MRC5 line cells. After preparing Valerian seeds, sowing them in March 2020, and harvesting the rhizome in October 2020, the extract was prepared from the valerian rhizome by maceration method. Valerian acid content was determined using high performance liquid chromatography (HPLC). Two cell lines (A549 and MRC-5) were used to study the effects of valerian extract, and the MTT test was used to evaluate cell viability. The expression of LL-37 mRNA and protein was assessed by Real-Time PCR and western blot, respectively. In vivo safety assessments and histopathological analysis were also conducted. Data was analyzed by Graphpad Prism 8 software. Valerian methanolic extract and valerenic acid upregulated the LL-37 mRNA and protein expression in both treated cell lines. Valerenic acid showed a greater effect on upregulating LL-37 expression than valerian methanolic extract. A549 cells were more sensitive to valerian methanolic extract compared to MRC5 cells, and its cell viability was reduced. Furthermore, liver and kidney-related safety assessments showed that valerian methanolic extract had no toxic effects. In general, it was concluded that the methanolic extract of valerian as well as the resulting valerenic acid as the most important component of the extract has the ability to upregulate LL-37expression. Therefore, methanolic extract of valerian and valerenic acid can be considered for improving the immune system.

Biosynthesis of valerenic acid by engineered Saccharomyces cerevisiae.

OBJECTIVE: To produce valerenic acid (VA) in Saccharomyces cerevisiae by engineering a heterologous synthetic pathway. RESULT: Valerena-4,7(11)-diene synthase (VDS) derived from Valeriana officinalis (valerian) was expressed in S. cerevisiae to generate valerena-4,7(11)-diene as the precursor of VA. By overexpressing the key genes of the mevalonate pathway ERG8, ERG12 and ERG19, and integrating 4 copies of MBP (maltose-binding protein)-VDS-ERG20 gene expression caskets into the genome, the production of valerena-4,7(11)-diene was improved to 75 mg/L. On this basis, the cytochrome P450 monooxygenase LsGAO2 derived from Lactuca sativa was expressed to oxidize valerena-4,7(11)-diene to produce VA, and the most effective VA production strain was used for fermentation. The yield of VA reached 2.8 mg/L in the flask and 6.8 mg/L in a 5-L bioreactor fed glucose. CONCLUSIONS: An S. cerevisiae strain was constructed and optimized to produce VA, but the valerena-4,7(11)-diene oxidation by LsGAO2 is still the rate-limiting step for VA synthesis that needs to be further optimized in future studies.

The sesquiterpenoid valerenic acid protects neuronal cells from the detrimental effects of the fungicide benomyl on apoptosis and DNA oxidation.

BACKGROUND: Valerenic acid (VA), a sesquiterpenoid of the plant Valeriana officinalis, has attracted attention of the research community due to its potential positive role against neurodegenerative diseases induced by chemicals. However, the relevant evidence in the literature is scarce. Therefore, this study aimed to examine the putative protective role of VA on the toxic effects of the fungicide benomyl on SH-SY5Y neural cells. METHODS: Cell viability was determined via the MTT and NRU assays, DNA damage was assessed via comet assay and apoptosis was evaluated through the expression of relevant genes. RESULTS: According to the results, exposure of the cells to benomyl enhanced viability inhibition and promoted DNA damage and apoptosis since the expression levels of the genes coding for MAPK8, NF-kB, Bax, Caspase-9 and Caspase-3 were increased. Treatment of the cells with VA ameliorated these effects in a concentration dependent manner. CONCLUSION: It is concluded that the molecular mechanism through which benomyl exerts its toxic action appears to depend on DNA oxidation and apoptosis induction. Furthermore, VA, a plant-derived compound is a protective antioxidant against pesticide-induced toxicity. Therefore, herbs, extracts and compounds of plant origin could be used as nutritional supplements that back up the beneficial role of medicine in neurodegenerative diseases.

Physiological and metabolic changes in two Himalayan medicinal herbs under drought, heat and combined stresses.

Valeriana jatamansi Jones and Hedychium spicatum Ham-ex-Smith are important medicinal herbs of the Himalayan region, which are highly demanded by pharmaceutical industries. Climatic variability especially increasing temperature and water deficit affects the growth and productivity of these species. In addition, increased temperature and water deficit may trigger the biosynthesis of medicinally important bioactive metabolites, which influence the quality of raw plant material and finished products. Therefore, V. jatamansi and H. spicatum plants were undertaken and subjected to different levels of drought (no irrigation), heat (35 °C), and combined stresses for investigating their physiological and metabolic responses. Both the treatments (individually and in combination) reduced relative water content, photosynthesis, carboxylation efficiency, chlorophyll content, while increased intracellular CO2, malondialdehyde and H2O2 content in both the species. Transpiration and stomatal conductance increased under heat and reduced under drought stress as compared to control. Water use efficiency was found to be increased under drought, while reduced under heat stress. Protein, proline, carotenoid content and antioxidant enzymes activities (superoxide dismutase, peroxidise, catalase) initially increased and thereafter decreased during late stages of stress. Exposure of plants to combined stress was more detrimental than individual stress. In V. jatamansi, exposure to drought stress significantly (p < 0.05) increased valerenic acid content in all plant parts (1.0-6.9 fold) with maximum increase after 20 days of exposure, while under heat stress, valerenic acid content increased (1.0-1.2 fold) in belowground part of V. jatamansi, and decreased (1.1-1.3 fold) in aerial part as compared to control. In H. spicatum, exposure of individual heat stress for 25-30 days and combined stress for 5-15 days significantly (p < 0.05) increased linalool content to 6.2-6.5 fold and 8.3-19.6 fold, respectively, as compared to control. Higher accumulation of bioactive compounds after exposure to mild stress provides encouraging prospects for enhancing pharmaceutical properties of these Himalayan herbs. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12298-021-01027-w.

Binding activity of Valeriana fauriei root extract on GABAA receptor flunitrazepam sites and distribution of its active ingredients in the brain of mice - A comparison with that of V. officinalis root.

ETHNOPHARMACOLOGICAL RELEVANCE: Valeriana fauriei root (VF) is a crude drug registered in the Japanese Pharmacopeia 17th Edition and a known substitute for V. officinalis (VO). Although VO has been pharmacologically evaluated for its sedative effects and mechanism of action, data regarding VF remain scarce. AIM OF THE STUDY: We compared the binding affinity of VF and VO extracts, as well as examined the active ingredients in the VF extract, on flunitrazepam sites of γ-aminobutyric acid receptor type A (GABAA receptor). Furthermore, we confirmed whether these active ingredients were distributed in the brain of mice orally administered the VF extract. MATERIALS AND METHODS: We prepared the assay system to evaluate the binding activity of flunitrazepam sites of GABAA receptor using a 96-well plate and assessed the activities of VF and VO extracts. We then analyzed their constituents using HPLC with principal component analysis (PCA) and evaluated active ingredients correlated with their activities. The distribution of active ingredients in the plasma and brain of mice orally administered the VF extract prepared with different emulsifiers were analyzed by LC-MS/MS. RESULTS: The ethanol extract of VF exhibited significantly higher activity on flunitrazepam sites of GABAA receptor than VO. For the VF extract, kessyl glycol diacetate (KGD) was markedly associated with the binding activities; however, active ingredients included KGD, kessyl glycol 8-acetate (KG8), α-kessyl acetate (α-KA), and coniferyl isovalerate (CI). For VO, valerenic acid and five other compounds were associated with the binding affinity on flunitrazepam sites of GABAA receptor. On emulsifying the VF extract with a fat-soluble glycerin fatty acid ester, the plasma and brain distributions of KGD tended to be higher, those of KG8 were significantly more than 10-times higher, and those of α-KA was lower than those of the VF extract emulsified with water-soluble gum arabic, after oral administration in mice. CONCLUSIONS: Based on the binding activity on flunitrazepam sites of GABAA receptor and brain distribution, KGD, KG8, and α-KA can be considered active ingredients of VF. The addition of a fat-soluble emulsifier promoted the absorption of KGD, the main active ingredient, and KGD was metabolized to KG8 in the body. The present results suggest a possible mechanism underlying the sedative effect for VF, and these three compounds can be used as marker compounds to evaluate the quality of VF products.

Ameliorative Effects of the Sesquiterpenoid Valerenic Acid on Oxidative Stress Induced in HepG2 Cells after Exposure to the Fungicide Benomyl.

Valerenic acid (VA) is a sesquiterpenoid and a phytoconstituent of the plant valerian used for sleeping disorders and anxiety. The frequency of using herbal components as therapeutic nutritional agents has increased lately. Their ability to improve redox homeostasis makes them a valuable approach against harmful xenobiotics. The purpose of this study was to evaluate the putative beneficial role of VA against the redox-perturbating role of the fungicide benomyl in HepG2 human liver cells in terms of oxidative stress in the cellular environment and in endoplasmic reticulum (ER). Benomyl increased cell total oxidant status and reactive oxygen species production and decreased total antioxidant status. The expression of genes coding for antioxidant molecules, namely, heme oxygenase-1, alpha glutathione s-transferase, NF-ĸB, and liver fatty acid binding protein, were decreased due to benomyl. VA ameliorated these effects. Benomyl also increased ER-stress-related molecules such as endoplasmic reticulum to nucleus signaling 1 protein, glucose-regulated protein 78, and caspase-12 levels, and VA acted also as a preventive agent. These results indicate that VA exerts ameliorative effects after benomyl-induced oxidative stress. VA, a widely used nutritional supplement, is a compound with potent antioxidant properties, which are valuable for the protection of cells against xenobiotic-induced oxidative damage.

Seasonal trends in morpho-physiological attributes and bioactive content of Valeriana jatamansi Jones under full sunlight and shade conditions.

Valeriana jatamansi Jones, an important medicinal herb of the Himalayan region, is an essential source of many therapeutic compounds and is traded/consumed in very high volume. The hypothesis of this study was that different seasons and light conditions may affect the content of medicinally valuable components with changes in the morpho-physiological attributes of the plant. Growing plants under suitable light conditions and harvesting of appropriate plant parts in optimum season is crucial for harnessing the full potential of the crop. Thus, the study was carried out to determine the seasonal response of V. jatamansi plants (genetically identical plants of same age) in terms of growth and phytochemical content under two different light conditions (full sunlight and 50% shade). During all seasons, growth parameters (plant height, leaf number, leaf area, relative water content, plant biomass) and the principle bioactive compounds (valerenic acid) were higher under shade conditions, while total flavonoids, tannins, phenolic compounds and antioxidant activities were higher under full sunlight conditions. HPLC analysis revealed that valerenic acid and most of the phenolic content were higher during summer season, especially in leaf part of the plant. The study suggested harvesting of V. jatamansi plants (especially leaf), during summer season to harness high quality raw material and to prevent loss of belowground parts. This strategy can be adopted by farmers for large scale cultivation of species. SUPPLEMENTARY INFORMATION: The online version of this article contains supplementary material available at 10.1007/s12298-021-00944-0.

A Review Focused on Molecular Mechanisms of Anxiolytic Effect of Valerina officinalis L. in Connection with Its Phytochemistry through in vitro/in vivo Studies.

Valeriana officinalis L. (Valerianaceae) is one of the most reputed ancient medicinal plants used in modern phytotherapy and traditional medicine. Its root extract is one of the most effective herbal sedatives and tranquilizers, where the plant is also used for the treatment of gastrointestinal spasms. V. officinalis has complex phytochemistry consisting of the esterified iridoid derivatives known as valepotriates (e.g., valtrate, didrovaltrate, isovalerenic acid), sesquiterpenes (e.g., valerenic acid), flavonoids (e.g., linarin, apigenin), lignans (e.g., pinoresinol, hydroxypinoresinol), alkaloids (e.g., actinidine, valerine), triterpenes (e.g., ursolic acid), monoterpenes (e.g., borneol, bornyl acetate). Among them, valerenic acid is a marker compound for standardization of the root extracts of the plant and has been reported in many in vitro/in vivo studies to be responsible for anxiolytic action of the plant. Although modulation of gamma-aminobutyric acid (GABA) receptors has been revealed to be the leading mechanism of the plant-based on the existence of valerenic acid, several studies described the interaction of valerenic acid with glutamergic receptors. In addition to valerenic acid, isovaleric acid, didrovaltrate, borneol, and some lignans have also been proposed to contribute to the anxiolytic effect of the plant. In the current review, the data selectively scrutinized from the in vitro/in vivo studies about identifying anxiolytic molecular mechanisms of V. officinalis is focused.

Effect of Elicitors on Morpho-Physiological Performance and Metabolites Enrichment in Valeriana jatamansi Cultivated Under Aeroponic Conditions.

The use of new agricultural technologies such as soilless and aeroponic cultivation systems is a valuable approach to medicinal plant production. The present study investigated the prospects of enhancing yield and secondary metabolite production in Valeriana jatamansi under aeroponic cultivation using elicitors, such as yeast extract and methyl jasmonate. Plants were evaluated by measuring growth parameters, photosynthetic rate, and secondary metabolites contents (on a dry weight basis). Maximum plant height (36.83 cm), leaf number (17.67), rootlet number (37.33), and rootlet length (6.90 cm) were observed at 0.5 mg/L yeast extract treatment; whereas treatment levels of 1.5 mg/L yeast extract and 150 µM methyl jasmonate resulted in maximum leaf length (6.95 cm) and leaf width (5.43 cm), respectively. Maximum photosynthetic rate (5.4053 µmol m-2s-1) and stomatal conductance (0.0656 mmol m-2s-1) were recorded at treatment levels of 0.5 mg/L and 1.5 mg/L yeast extract respectively, whereas at 150 µM methyl jasmonate treatment, transpiration rate was 0.9046 mmol m-2s-1. In aeroponic cultivation, the maximum content of valerenic acid and hydroxy valerenic acid was detected in leaf (2.47 and 8.37 mg/g) and root (1.78 and 7.89 mg/g) at treatment levels of 100 µM and 150 µM methyl jasmonate, respectively. Acetoxy valerenic acid was highest in leaf (1.02 mg/g) at 1.5 mg/L yeast extract, and in the root (2.38 mg/g) at 150 µM methyl jasmonate. Gas chromatography-mass spectrometry analysis identified twenty-eight volatile compounds in roots, of which three-isovaleric acid (6.72-50.81%), patchouli alcohol (13.48-25.31%) and baldrinal (0.74-25.26%)-were the major constituents. The results revealed that, besides roots, leaves could also be utilized as a prominent alternative source for targeted secondary metabolites. In conclusion, aeroponic cultivation offers year-round quality biomass production and ease to access subsequent roots harvest in V. jatamansi, to meet the demand of the pharmaceutical industries.

5-HT receptor agonist Valerenic Acid enhances the innate immunity signal and suppresses glioblastoma cell growth and invasion.

Glioblastoma multiform (GBM) continues to threaten people's lives due to the limited therapeutic strategies. As a new drug, Valerenic Acid suppresses the progression of GBM, however, the mechanism is largely unknown. Here, we found that Valerenic Acid can inhibit cell proliferation, migration and invasion of GBM cells by increasing innate immune signals such as enhancing ROS levels and activating the AMPK pathway. Inhibition of ROS by N-acetylcysteine (NAC) or attenuation of AMPK by Compound C could block Valerenic Acid-induced cell death. Additionally, the xenograft mouse model also confirmed that Valerenic Acid had anti-tumor effect. Together, our results provide compelling rational to develop Valerenic Acid as an anti-tumor agent against GBM patients.

"Effect of valerenic acid on neuroinflammation in a MPTP-induced mouse model of Parkinson's disease".

Parkinson´s disease is the most important neuromotor pathology due to the prominent loss of dopaminergic neurons in the substantia nigra pars compacta. There is an inherent deficiency of dopamine in Parkinson´s disease, which is aggravated when neuroinflammatory processes are present. Several biomolecules are interesting candidates for the regulation of inflammation and possible neuroprotection, such as valerenic acid, one of the main components of Valeriana officinalis. A 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (MPTP)-induced mouse model of Parkinson's disease was developed to evaluate the motor effects of valerenic acid. The evaluation was carried out with four tests (an invert screen test for muscle strength, cross beam test, open field mobility test and lifting on hind legs test). Subsequently, the neuroinflammatory process was evaluated through ELISA of pro-inflammatory cytokines (IL-1ß, IL-6, TNF-α and IFN-γ). The decreases in the inflammatory and neurodegenerative processes were evaluated by Western blot and immunohistochemistry analyses of the tissues, which included an evaluation of the tyrosine hydroxylase and GFAP proteins. Finally, the predicted mechanism of action of valerenic acid was supported by molecular docking calculations with the 5-HT5A receptor. The results indicate that the use of valerenic acid as a co-treatment decreases the neuroinflammation in Parkinson's disease induced by MPTP and provides evidence of a decrease in the evaluated pro-inflammatory cytokines and in the amount of GFAP in the mesencephalic area. Valerenic acid prevents neuroinflammation in a Parkinson's disease mouse model, which might reflect the neuroprotection of dopaminergic neurons with the recovery of motor ability.

The Effect of Methanolic Valeriana officinalis Root Extract on Adipocyte Differentiation and Adiponectin Production in 3T3-L1 Adipocytes.

Adipose tissue is an endocrine organ and its endocrine function is closely associated with type 2 diabetes mellitus. Valeriana officinalis (Valerian) exerts some physiological effects; however, its influence on adipocytes remains unclear. We investigated the effect of methanolic Valerian root extract (Vale) on 3T3-L1 adipocytes. Vale (1, 10, and 100 µg/mL) dose-dependently promoted adipocyte differentiation with increasing lipid accumulation. In addition, Vale significantly increased the mRNA levels in genes associated with adipocyte differentiation, including peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding protein α , and adipocyte protein 2, in dose-dependent manner. Vale also significantly enhanced mRNA and protein levels in adiponectin. A PPARγ antagonist assay and a PPARγ binding assay revealed that Vale-induced increased adipocyte differentiation and adiponectin production were partly associated with direct binding to PPARγ. Valerenic acid, a characteristic component in Valerian, also demonstrated the ability to induce adipocyte differentiation and adiponectin secretion, suggesting that it is one of the functional components in Vale.

The roles of valerenic acid on BDNF expression in the SH-SY5Y cell.

The roots of Valeriana officinalis L. (Valerianaceae) are used for treating sleep disorders and/or mild nerve tension. The effect of valerenic acid on brain-derived neurotrophic factor (BDNF) has not yet been studied, although it is known that gamma-amino butyric acid A (GABAA) receptor is regulated by BDNF, which modulates the depressive-like behavior and neurogenesis. The purpose of this study is to determine the effect of V. officinalis root extract (VO), its main constituents valerenic acid (VA) and acetoxy valerenic acid (AVA) as well as valerenic acid-free (VAF), acetoxy valerenic acid-free (AVAF) extracts and increasing amounts of valerenic acid containing extracts on the BDNF expression in SH-SY5Y cell lines. The effect of methanolic extracts of VO, VA, AVA, VAF, AVAF, and the extracts whose amount of VA were increased gradually, were tested using a Human BDNF ELISA kit with 17ß-estradiol as a positive control. The VO and VA extracts caused a significant (p < 0.001) increase in the BDNF expression in SH-SY5Y cells compared to control. This effect completely disappeared when cells were treated with VAF extract. AVA alone did not show any significant change in the BDNF levels. The extracts with increasing amount of VA led to a concentration- dependent effect on the cells. In conclusion, our findings suggest that the antidepressant-like effect of the VO extract is also related to BDNF expression, and that this is mainly due to the presence of VA in the extract. Removing VA from VO extract leads to a loss of activity. Moreover, the concentration of VA plays a role for BDNF expressions in SH-SY5Y cells, which demonstrates the importance of quality control on the commercially available products.

Metabolic engineering of Escherichia coli for production of valerenadiene.

Valeriana officinalis is a medicinal herb which produces a suite of compounds in its root tissue useful for treatment of anxiety and insomnia. The sesquiterpene components of the root extract, valerenic acid and valerena-1,10-diene, are thought to contribute to most of the observed anxiolytic of Valerian root preparations. However, valerenic acid and its biosynthetic intermediates are only produced in low quantities in the roots of V. officinalis. Thus, in this report, Escherichia coli was metabolically engineered to produce substantial quantities of valerena-1,10-diene in shake flask fermentations with decane overlay. Expression of the wildtype valerenadiene synthase gene (pZE-wvds) resulted in production of 12µg/mL in LB cultures using endogenous FPP metabolism. Expression of a codon-optimized version of the valerenadiene synthase gene (pZE-cvds) resulted in 3-fold higher titers of valerenadiene (32µg/mL). Co-expression of pZE-cvds with an engineered methyl erythritol phosphate (MEP) pathway improved valerenadiene titers 65-fold to 2.09mg/L valerenadiene. Optimization of the fermentation medium to include glycerol supplementation enhanced yields by another 5.5-fold (11.0mg/L valerenadiene). The highest production of valerenadiene resulted from engineering the codon-optimized valerenadiene synthase gene under strong Ptrc and PT7 promoters and via co-expression of an exogenous mevalonate (MVA) pathway. These efforts resulted in an E. coli production strain that produced 62.0mg/L valerenadiene (19.4mg/L/OD600 specific productivity). This E. coli production platform will serve as the foundation for the synthesis of novel valerenic acid analogues potentially useful for the treatment of anxiety disorders.

The design, synthesis, and anti-inflammatory evaluation of a drug-like library based on the natural product valerenic acid.

The plant natural product, valerenic acid (1) was chosen as a desirable scaffold for the generation of a novel screening library due to its drug-like physicochemical parameters (such as LogP, hydrogen bond donor/acceptor counts, and molecular weight). An 11-membered amide library (2-12) was subsequently generated using parallel solution-phase synthesis and Ghosez's reagent. The chemical structures of all semi-synthetic analogues (2-12) were elucidated following analysis of the NMR, MS, UV and IR data. The structures of compounds 8 and 11 were also confirmed by X-ray crystallographic analysis. All library members were evaluated for their ability to inhibit the release of IL-8 and TNF-α. Six analogues showed moderate activity in the IL-8 assay with IC50 values of 2.8-8.3µM, while none of the tested compounds showed any significant effect on inhibiting TNF-α release.

Expression of Terpenoid Biosynthetic Genes and Accumulation of Chemical Constituents in Valeriana fauriei.

Valeriana fauriei (V. fauriei), which emits a characteristic and unpleasant odor, is important in traditional medicine. In this study, the expression of terpenoid biosynthetic genes was investigated in different organs that were also screened for volatile compounds including valerenic acid and its derivatives. Specific expression patterns from different parts of V. fauriei were observed using quantitative real-time PCR (qRT-PCR). The highest transcript levels of biosynthetic genes involved in mevalonic acid (MVA) and methylerythritol phosphate (MEP) production were found in the stem. Although the amounts of volatile compounds were varied by organ, most of the volatile terpenoids were accumulated in the root. Gas chromatography mass spectrometry (GC-MS) analysis identified 128 volatile compounds, which represented 65.33% to 95.66% of total volatiles. Certain compounds were only found in specific organs. For example, isovalerenic acid and valerenic acid and its derivatives were restricted to the root. Organs with high transcript levels did not necessarily have high levels of the corresponding chemical constituents. According to these results, we hypothesize that translocation may occur between different organs in V. fauriei.