Bioactive constituents of Chinese natural medicines. II. Rhodiolae radix. (1). Chemical structures and antiallergic activity of rhodiocyanosides A and B from the underground part of Rhodiola quadrifida (Pall.) Fisch. et Mey. (Crassulaceae)

Phytochemical profile and anti-inflammatory activity of a commercially available Rhodiola rosea root extract

Rhodiola rosea roots and rhizomes hold an important place in the folk medicines of Russia, Scandinavia, Mongolia, and China as a health supplement for stimulating the nervous system, enhancing physical and mental performances, and nowadays they constitute the active ingredient in many popular commercial preparations sold worldwide as food additives, pharmaceutical remedies, and drinks. This study was aimed at providing a detailed phytochemical characterization of the Rhodiola 5%, a commercially available extract of R. rosea roots, and resulted in the characterization of 18 secondary metabolites, including 13 polyphenols and 6 terpenoids, and in the discovery of the new rhodiosidin (5), the first R. rosea metabolite to show both terpenoid and cinnamoyl moieties. The 5-lipoxygenase inhibiting activity of the main components was characterized and disclosed that rosiridin (6), kenposide A and rosavins are mainly responsible for this activity of the extract.

The Effect of Low Positive Temperatures on the Formation of Secondary Metabolites in Rhodiola quadrifida (Pall.) Fisch. et C.A. Mey. In Vitro Cultures

Global warming is one of the most serious problems leading to changes in the distribution areas of species and biodiversity. Rhodiola quadrifida is a rare plant with adaptogenic properties and grows in the highlands in a narrow temperature range of 2–15 °C. The aim of our work was to study the growth and content of the main metabolites in two in vitro cultures of Rhodiola quadrifida at temperatures of 5, 15 and 25 °C. Hairy roots and calli were cultivated on agar medium for 28 days. The maximum values of the growth index were observed at 25 °C (2.32 and 2.12 for calli and hairy roots, respectively). HPLC-MS showed the absence of tyrosol and rosarin in both cultures, and rosin in the root culture. The content of salidroside changed slightly in calli and roots. Cultivation at 5 °C significantly stimulated the formation of rosin in calli. Only a residual amount of rosavin was noted in the roots, regardless of temperature. The content of rosin was higher in calli at 15 °C with a maximum content at the end of the cultivation cycle 25 µg/g DW. Thus, Rhodiola quadrifida will be able to grow with an increase in temperature by 10 °C but this will be accompanied by a significant reduction in its medicinal value

Collection of Hairy Roots as a Basis for Fundamental and Applied Research

Due to population growth, instability of climatic conditions, and reduction of the areas of natural ecosystems, it becomes necessary to involve modern biotechnological approaches to obtain highly productive plant material. This statement applies both to the creation of plant varieties and the production of new pharmaceutical raw materials. Genetic transformation of valuable medicinal plants using Agrobacterium rhizogenes ensures the production of stable and rapidly growing hairy roots cultures that have a number of advantages compared with cell culture and, above all, can synthesize root-specific substances at the level of the roots of the intact plant. In this regard, special attention should be paid to the collection of hairy roots of the Institute of Plant Physiology RAS, Russian Academy of Sciences, the founder of which was Dr. Kuzovkina I.N. Currently, the collection contains 38 hairy roots lines of valuable medicinal and forage plants. The review discusses the prospects of creating a hairy roots collection as a basis for fundamental research and commercial purposes.

Mixing ratio optimization for functional complex extracts of Rhodiola crenulata, Panax quinquefolius, and Astragalus membranaceus using mixture design and verification of immune functional efficacy in animal models

We aimed to identify the optimum mixing ratio for various ingredients to obtain complex extracts with high extract yields and immune-enhancing activity in animals. The extract yield and amounts of nitric oxide (NO) and interleukin (IL)-6 were set to maximum for modeling predictions. The predicted optimum values for the mixing ratio were 49.5% for Rhodiola crenulata, 26.1% for Astragalus membranaceus, and 24.4% for Panax quinquefolius, and the predicted response values were 31.5% yield, 13.4% NO production, and 6.1% IL-6 production; actual values were 35.3% yield, 14.7% NO, and 6.6% IL-6. The optimum mixing ratio extract (OMRE) was used for the animal experiments. Treating mice with OMRE at 200 mg/kg produced significant increases in spleen indexes and T-cell/B-cell proliferation. OMRE treatment increased IL-10 and IL-6 production in concanavalin A- and lipopolysaccharide-induced T- and B- lymphocytes, respectively. These results provide a basis for the development of functional extracts and drinks.

Anti-prostate cancer potential of gossypetin via inducing apoptotic and autophagic cell death

Gossypetin (GTIN), a naturally occurring hexahydroxy flavone, has been shown to possess antimutagenic, antioxidant, antimicrobial, and antiatherosclerotic effects. Here, we investigated the mechanism(s) underlying the anticancer potential of GTIN. In this study, investigations were showed that GTIN preferentially induces programed cell death of prostate cancer (PCa) cells in vitro and in vivo. MTT data showed that GTIN exhibited the anti-proliferation effect on human PCa cells in a dose- and time-dependent manner. Among two kinds of PCa cells, androgen-dependent LNCaP cells were the most susceptible to GTIN. GTIN was evaluated for apoptotic and autophagic activities in LNCaP cells, but not in androgen-independent DU145 cells with mutant Atg5 and resistant to autophagy. Molecular data showed the apoptotic effect of GTIN at a high dose in PCa cells might be mediated via mitochondrial pathway. The lower dose of GTIN-induced autophagy enhances LNCaP cell death, and is dependent on class III PI3K and Atg5 pathway. Finally, GTIN was evidenced by its inhibition on the growth of LNCaP cells in xenograft tumor studies. As a result, our data presented the first evidence of GTIN as an inducer of apoptotic and autophagic cell death in LNCaP cells, and provide a new mechanism for its anticancer activity.

Preventive Effects of Rhodiola rosea L. on Bleomycin-Induced Pulmonary Fibrosis in Rats

Rhodiola rosea L. (RRL) possesses a wide range of pharmacological properties, including lung-protective activity, and has been utilized in folk medicine for several 100 years. However, the lung-protective mechanism remains unclear. This study investigated the possible lung-protective activity mechanism of RRL in a pulmonary fibrosis (PF) rat model. Lung fibrotic injury was induced in Sprague-Dawley rats by single intratracheal instillation of saline containing bleomycin (BLM; 5 mg/kg). The rats were administered 125, 250, or 500 mg/kg of a 95% ethanol extract of RRL for 28 days. The animals were killed to detect changes in body weight, serum levels of glutathione (GSH) and total superoxide dismutase (T-SOD), as well as lung tissue hydroxyproline (HYP) content. Tumor necrosis factor-α (TNF-α), transforming growth factor-β1 (TGF-β1), and interleukin 6 (IL-6) levels were measured in bronchoalveolar lavage fluid (BALF) by enzyme-linked immunosorbent assay. Hematoxylin and eosin, Masson's trichrome, and immunohistochemical staining were performed to observe the histopathological changes in lung tissues. Additionally, target-related proteins were measured by Western blotting. RRL alleviated the loss of body weight induced by instilling BLM in PF rats, particularly at the 500 mg/kg per day dose. RRL reduced HYP (p < 0.01) and increased GSH and T-SOD contents. BALF levels of TNF-α, TGF-β1, and IL-6 decreased significantly in the RRL-treated groups. Expression levels of matrix metalloproteinase-9 (MMP-9) and α-smooth muscle actin decreased significantly in a dose-dependent manner in response to RRL. Moreover, the levels of TGF-β1 and tissue inhibitor of metalloproteinase-1 in lung tissues also decreased in the RRL-treated groups. RRL alleviated BLM-induced PF in rats. Our results reveal that the protective effects of RRL against fibrotic lung injury in rats are correlated with its anti-inflammatory, antioxidative, and anti-fibrotic properties. MMP-9 may play important roles in BLM-induced PF.

New acyclic secondary metabolites from the biologically active fraction of Albizia lebbeck flowers

The total extract of Albizia lebbeck flowers was examined in vivo for its possible hepatoprotective activity in comparison with the standard drug silymarin at two doses. The higher dose expressed promising activity especially in reducing the levels of AST, ALT and bilirubin. Fractionation via liquid–liquid partition and reexamination of the fractions revealed that the n-butanol fraction was the best in improving liver biochemical parameters followed by the n-hexane fraction. However, serum lipid parameters were best improved with CHCl₃ fraction. The promising biological activity results initiated an intensive chromatographic purification of A. lebbeck flowers fractions. Two compounds were identified from natural source for the first time, the acyclic farnesyl sesquiterpene glycoside1-O-[6-O-α-l-arabinopyranosyl-β-d-glucopyranoside]-(2E,6E-)-farnesol (6) and the squalene derivative 2,3-dihydroxy-2,3-dihydrosqualene (9), in addition to eight compounds reported here for the first time from the genus Albizia; two benzyl glycosides, benzyl 1-O-β-d-glucopyranoside (1) and benzyl 6-O-α-l-arabinopyranosyl β-d-glucopyranoside (2); three acyclic monoterpene glycosides, linalyl β-d-glucopyranoside (3) and linalyl 6-O-α-l-arabinopyranosyl-β-d-glucopyranoside (4); (2E)-3,7-dimethylocta-2,6-dienoate-6-O-α-l arabinopyranosyl-β-d-glucopyranoside (5), two oligoglycosides, n-hexyl-α-l arabinopyranosyl-(1 → 6)-β-d-glucopyranoside (creoside) (7) and n-octyl α-l-arabinopyranosyl-(1 → 6)-β-d-glucopyranoside (rhodiooctanoside) (8); and ethyl fructofuranoside (10). The structures of the isolated compounds were elucidated based on extensive examination of their spectroscopic 1D and 2D-NMR, MS, UV, and IR data. It is worth mentioning that, some of the isolated linalol glycoside derivatives were reported as aroma precursors.

Comparison of Antioxidant Capability after Isopropanol Salting-Out Pretreatment and n-Butanol Partition Extraction, and Identification and Evaluation of Antioxidants of Sedum formosanum N.E.Br

Crude extracts of Sedum formosanum N.E.Br. obtained from n-butanol partition (BP) and isopropanol salting-out pretreatment (ISP) were analyzed using antioxidation assays. The results indicated that the extract from ISP contained more potent antioxidants and thus exhibited more antioxidant activity in all the assays. The superoxide radical-scavenging activity and inhibition of nitric oxide radicals achieved after ISP were 3.65 and 2.18 times higher than those achieved through BP, respectively. Eight bioactive natural products were isolated and identified according to an analysis of antioxidation activity in different fractions of the ISP crude extract, namely three cyanophoric glycosides 1-3, three flavonoids 4-6 and two phenolic compounds (7 and a new compound 8). Among them, compounds 5 and 6 exhibit the highest antioxidation capability, and the ISP is suitable for obtaining compounds 5 and 6 using HPLC chromatograms. Therefore, ISP is an excellent extraction technology that can be used to extract antioxidant compounds in the nutraceutical and pharmaceutical industries.

A New Triglycosyl Flavonoid Isolated from Leaf Juice of Kalanchoe gastonis-bonnieri (Crassulaceae)

Kalanchoe gastonis-bonnieri R. Hamet & H. Perrier (Crassulaceae) is a succulent species empirically used as a vaginal contraceptive as well as to heal genitourinary infections. A phytochemical study of leaf juice prepared from specimens collected in the flowering season resulted in the isolation of the new flavonoid quercetin 3- O-α-rhamnopyranoside-7- O-β-D-glucopyranosyl-(1→3)-α-L-rhamnopyranoside, as well as the already known 6- C-β-D-glucopyranosyl-8- C-β-D-glucopyranosylapigenin (vicenin-2). The NMR spectra of this flavonoid at room temperature exhibited broad and duplicated signals, suggesting the existence of rotameric conformers, which was confirmed by coalescence of the signals at 40°C. The structural elucidation was based on 1H and 13C NMR (HMQC and HMBC) analyses and MS data. This is the first report of a C-glycosyl flavonoid (vicenin-2) in the Crassulaceae family. Additionally, this is the first study in which atropoisomerism has been shown for vicenin-2.

Biotechnological approaches to enhance salidroside, rosin and its derivatives production in selected Rhodiola spp. in vitro cultures

Rhodiola (Crassulaceae) an arctic-alpine plant, is extensively used in traditional folk medicine in Asian and European countries. A number of investigations have demonstrated that Rhodiola preparations exhibit adaptogenic, neuroprotective, anti-tumour, cardioprotective, and anti-depressant effects. The main compounds responsible for these activities are believed to be salidroside, rosin and its derivatives which became the target of biotechnological investigations. This review summarizes the results of the diverse biotechnological approaches undertaken to enhance the production of salidroside, rosin and its derivatives in callus, cell suspension and organ in vitro cultures of selected Rhodiola species.

Dodecyl α-L-rhamnopyranosyl-(1→2)-β-D-fucopyranoside derivatives from the glandular trichome exudate of Erodium pelargoniflorum

Chemical investigation of the glandular trichome exudate of Erodium pelargoniflorum (Geraniaceae) led to the isolation of two dodecyl disaccharide derivatives, named pelargoside A1 and pelargoside B1 (1 and 2, resp.). The structures of 1 and 2 were determined as dodecyl 4-O-acetyl-α-L-rhamnopyranosyl-(1→2)-4-O-acetyl-β-D-fucopyranoside and dodecyl 3,4-di-O-acetyl-α-L-rhamnopyranosyl-(1→2)-4-O-acetyl-β-D-fucopyranoside, respectively, by spectroscopic studies, including 2D-NMR, and chemical transformations. In addition, undecyl, tridecyl, and tetradecyl homologs of 1 and 2, named pelargosides A2-A4 and pelargosides B2-B4, were also characterized as minor constituents of the exudate.

Purification of Phenylalkanoids and monoterpene glycosides from Rhodiola rosea L. roots by high-speed counter-current chromatography

INTRODUCTION

Rhodiola rosea L. is a medicinal herb used for its adaptogenic properties. The main active components are the phenylpropanoids collectively referred to as rosavins.

OBJECTIVES

To develop an isolation method for phytochemicals present in Rhodiola rosea roots using high-speed counter-current chromatography (HSCCC).

METHODOLOGY

The roots of Rhodiola rosea were extracted with methanol and fractionated using liquid-liquid partition and polyamide column clean-up. The purified fraction (100 mg) was subjected to semi-preparative HSCCC using the two-phase solvent system ethyl acetate:butanol:water (3:2:5). The head-to-tail elution mode was employed with a flow rate of 1.5 mL/min and a rotary speed of 1000 rpm.

RESULTS

The separation yielded six main fractions with four components more than 90% pure. The sixth fraction was further purified using semi-preparative HPLC with a Synergi-hydro RP C₁₈ -column to obtain rosin and geranyl 1-O-α-l-arabinopyranosyl(1 → 6)-β-d-glucopyranoside. The main components isolated were rosavin (3.4 mg, 97% purity), salidroside (0.5 mg, 90% purity), benzyl-O-β-d-glucopyranoside (1.2 mg, 85% purity), rosarin (1.3 mg, 99% purity), rosiridin (1.8 mg, 92% purity), rosin (1.2 mg, 95% purity) and geranyl 1-O-α-l-arabinopyranosyl(1 → 6)-β-d-glucopyranoside (6.5 mg, 97% purity). The identity and purity of these components were confirmed using ultrafast liquid chromatography-diode-array detector-MS/MS analysis,  ¹H- and ¹³C-NMR spectroscopy.

CONCLUSION

High-speed counter-current chromatography was successful in the isolation of several phytochemicals present in Rhodiola rosea roots, including two components that are not commercially available.

Biosynthesis of rhodiocyanosides in Lotus japonicus: rhodiocyanoside A is synthesized from (Z)-2-methylbutanaloxime via 2-methyl-2-butenenitrile

Lotus japonicus contains the two cyanogenic glucosides, linamarin and lotaustralin, and the non cyanogenic hydroxynitriles, rhodiocyanoside A and D, with rhodiocyanoside A as the major rhodiocyanoside. Rhodiocyanosides are structurally related to cyanogenic glucosides but are not cyanogenic. In vitro administration of intermediates of the lotaustralin pathway to microsomes prepared from selected L. japonicus accessions identified 2-methyl-2-butenenitrile as an intermediate in the rhodiocyanoside biosynthetic pathway. In vitro inhibitory studies with carbon monoxide and tetcyclacis indicate that the conversion of (Z)-2-methylbutanal oxime to 2-methyl-2-butenenitrile is catalyzed by cytochrome P450(s). Carbon monoxide inhibited cyanogenic glucosides as well as rhodiocyanosides synthesis, but inhibition of the latter pathway was much stronger. These results demonstrate that the cyanogenic glucoside and rhodiocyanosides pathways share CYP79Ds to obtain (Z)-2-methylbutanaloxime from l-isoleucine, whereas the subsequent conversions are catalyzed by different P450s. The aglycon of rhodiocyanoside A forms the cyclic product 3-methyl-2(5H)-furanone. Furanones are known to possess antimicrobial properties indicating that rhodiocyanoside A may have evolved to serve as a phytoanticipin that following β-glucosidase activation and cyclization of the aglycone formed, give rise to a potent defense compound.

Effects of a Rhodiola rosea L. extract on the acquisition, expression, extinction, and reinstatement of morphine-induced conditioned place preference in mice

RATIONALE

Opioid addiction is a chronic, recurrent brain disease that is characterised by compulsive drug seeking and a high rate of relapse even after long periods of abstinence. Prevention of relapse is the primary goal of addiction treatment and is still the major limitation in drug therapy.

OBJECTIVES

The present study investigated the effects of a Rhodiola rosea L. hydroalcoholic extract (RHO), a well-known traditional oriental medicine, on establishment and reinstatement of morphine-induced conditioned place preference (CPP) in mice.

METHODS

CPP was induced by intraperitoneal injection of morphine (10 mg/kg) as an 8-day conditioning schedule. The effects of RHO on the rewarding properties of morphine were tested in mice receiving oral administration of RHO (10, 15, and 20 mg/kg) 60 min prior to each morphine injection (acquisition) or prior to the CPP test on day 9 (expression). Once established, CPP was extinguished by repeated testing, during which conditioned mice were injected daily with different doses of RHO. Finally, the efficacy of RHO in blocking reinstatement of CPP provoked by priming injections and physical stress was also evaluated.

RESULTS

RHO administration showed dose dependency for prevention of establishment of CPP and was effective in facilitating extinction of morphine-induced CPP. RHO suppressed both priming- and stress-induced reinstatement of CPP in a dose-dependent manner.

CONCLUSIONS

In conclusion, as RHO was effective for reducing craving and vulnerability to relapse, it might be a very effective natural remedy for the treatment of opioid addiction.

Structural requirements of flavonoids for the adipogenesis of 3T3-L1 cells

To search for a new class of antidiabetic compounds, effects of 44 flavonoids on the adipogenesis of 3T3-L1 cells were examined. Among them, 3,4',7-trimethylkaempferol, tetramethylkaempferol, and pentamethylquercetin concentration-dependently enhanced the accumulation of triglyceride, a marker of adipogenesis. With regard to structural requirements of flavonoids for the activity, it was fond that: (1) most flavonoids having hydroxy groups lacked the effect; (2) flavonols with methoxy groups showed stronger effects particularly those with a methoxy group at the 3-position; and (3) a methoxy group of flavonols at the B ring was also important. 3,4',7-Trimethylkaempferol, tetramethylkaempferol, and pentamethylquercetin significantly increased the amount of adiponectin released into the medium and the uptake of 2-deoxyglucose into the cells. Furthermore, tetramethylkaempferol and pentamethylquercetin also increased mRNA levels of adiponectin, glucose transporter 4 (GLUT4), and fatty acid-binding protein (aP2). Both compounds also increased the mRNA levels of peroxisome proliferator-activated receptor (PPAR)γ2 and CCAAT/enhancer-binding protein (C/EBP)α, β, and/or δ, although, different from troglitazone, they did not activate PPARγ directly in a nuclear receptor cofactor assay.

Evaluation of Rhodiola rosea L. extract on affective and physical signs of nicotine withdrawal in mice

The aim of the present study was to investigate the effects of a Rhodiola rosea L. extract on the prevention of the development of nicotine dependence and for the reduction of abstinence suffering following nicotine cessation in mice. Dependence was induced in mice by subcutaneous injections of nicotine (2 mg/kg, 4 times/day) for eight days. Spontaneous abstinence syndrome was evaluated 20 h after the last nicotine administration, by analysis of withdrawal signs, as affective (anxiety-like behaviour) and physical (somatic signs and locomotor activity). Rhodiola rosea L. extract was administered orally during nicotine treatment (10, 15 and 20 mg/kg) or during nicotine withdrawal (20 mg/kg). Results show that both affective and somatic signs (head shaking, paw tremors, body tremors, ptosis, jumping, piloerection and chewing) induced by nicotine withdrawal are abolished by administration of Rhodiola rosea L. extract in a dose-dependent fashion, during both nicotine exposure and nicotine cessation. In conclusion, our data encourage additional studies to define the use of R. rosea L. as a therapeutic approach in the treatment of smoking cessation.

Effects of a Rhodiola rosea L. extract on acquisition and expression of morphine tolerance and dependence in mice

This study investigated the effect of Rhodiola rosea L. extract on acquisition and expression of morphine tolerance and dependence in mice. Therefore animals were injected with repeated administration of morphine (10 mg/kg, subcutaneous) twice daily for five or six days, in order to make them tolerant or dependent. Rhodiola rosea L. extract (0, 10, 15 and 20 mg/kg) was administered by the intragastric route 60 min prior to each morphine injection (for acquisition) or prior the last injection of morphine or naloxone on test day (for tolerance or dependence expression, respectively). Morphine tolerance was evaluated by testing its analgesic effect in the tail flick test at the 1st and 5th days. Morphine dependence was evaluated by counting the number of withdrawal signs (jumping, rearing, forepaw tremor, teeth chatter) after naloxone injection (5 mg/kg; intraperitoneal) on the test day (day 6). Results showed that Rhodiola rosea L. extract significantly reduced the expression of morphine tolerance, while it was ineffective in modulating its acquisition. Conversely, Rhodiola rosea L. extract significantly and dose-dependently attenuated both development and expression of morphine dependence after chronic or acute administration. These data suggest that Rhodiola rosea L. may have human therapeutic potential for treatment of opioid addiction.

Matrix metalloproteinase inhibitors (MMPIs) from marine natural products: the current situation and future prospects

Matrix metalloproteinases (MMPs) are a family of more than twenty five secreted and membrane-bound zinc-endopeptidases which can degrade extracellular matrix (ECM) components. They also play important roles in a variety of biological and pathological processes. Matrix metalloproteinase inhibitors (MMPIs) have been identified as potential therapeutic candidates for metastasis, arthritis, chronic inflammation and wrinkle formation. Up to present, more than 20,000 new compounds have been isolated from marine organisms, where considerable numbers of these naturally occurring derivatives are developed as potential candidates for pharmaceutical application. Eventhough the quantity of marine derived MMPIs is less when compare with the MMPIs derived from terrestrial materials, huge potential for bioactivity of these marine derived MMPIs has lead to large number of researches. Saccharoids, flavonoids and polyphones, fatty acids are the most important groups of MMPIs derived from marine natural products. In this review we focus on the progress of MMPIs from marine natural products.

Matrix metalloproteinase inhibitors (MMPIs) from marine natural products: the current situation and future prospects

Matrix metalloproteinases (MMPs) are a family of more than twenty five secreted and membrane-bound zinc-endopeptidases which can degrade extracellular matrix (ECM) components. They also play important roles in a variety of biological and pathological processes. Matrix metalloproteinase inhibitors (MMPIs) have been identified as potential therapeutic candidates for metastasis, arthritis, chronic inflammation and wrinkle formation. Up to present, more than 20,000 new compounds have been isolated from marine organisms, where considerable numbers of these naturally occurring derivatives are developed as potential candidates for pharmaceutical application. Eventhough the quantity of marine derived MMPIs is less when compare with the MMPIs derived from terrestrial materials, huge potential for bioactivity of these marine derived MMPIs has lead to large number of researches. Saccharoids, flavonoids and polyphones, fatty acids are the most important groups of MMPIs derived from marine natural products. In this review we focus on the progress of MMPIs from marine natural products.

Effects of Rhodiola rosea L. extract on behavioural and physiological alterations induced by chronic mild stress in female rats

Rhodiola rosea L. is one of the most popular adaptogen and an antistress plant in European and Asiatic traditional medicine. Our previous studies have confirmed the adaptogenic and antistress properties of a single administration of R. rosea L. extract in rats exposed to acute stress. There is increasing evidence that prolonged exposure to stressful life events and depression are both related to significant behavioural, endocrinological and neurobiological changes in human and animal subjects. The aim of this study was to determine whether chronic treatment with a hydroalcoholic R. rosea extract (RHO) standardized in 3% rosavin and 1% salidroside can prevent alterations induced in female rats following 6 weeks of a chronic mild stress (CMS) procedure. This was analysed through the behavioural and physiological parameters of consumption of 1% sucrose solution, locomotor and exploratory activities, body weight gain and oestrous cycle length. After the first 3 weeks of stress, RHO was administered daily by gavage at doses of 10, 15 and 20 mg/kg for the remaining 3 weeks. In addition, the antidepressant drug fluoxetine (10 mg/kg os), which has been shown to reverse CMS-induced disruptions, was used as the reference treatment. Rats subjected to the CMS procedure demonstrated decreased sucrose intake, reduced moving behaviour, minimized weight gain and dysregulation of their oestrous cycle. Treatment with RHO completely reverted all of these changes. The effects of RHO were comparable to those of fluoxetine. Interestingly, neither RHO nor fluoxetine influence the behavioural and physiological parameters tested in non-stressed animals. These findings strongly showed that chronic administration of RHO results in potent inhibition of the behavioural and physiological changes induced by chronic exposure to mild stressors.

Bioactive constituents from Chinese natural medicines. XXXII. aminopeptidase N and aldose reductase inhibitors from Sinocrassula indica: structures of sinocrassosides B(4), B(5), C(1), and D(1)-D(3)

From the methanolic extract of the whole plant of Sinocrassula indica (Crassulaceae), six new flavonol glycosides, sinocrassosides B(4) (1), B(5) (2), C(1) (3), D(1) (4), D(2) (5), and D(3) (6), were isolated together with 30 compounds. The structures of 1-6 were elucidated on the basis of chemical and physicochemical evidence. In addition, several constituents were found to show inhibitory effects on aminopeptidase N and aldose reductase.

Hydroxynitrile glucosides

beta- and gamma-Hydroxynitrile glucosides are structurally related to cyanogenic glucosides (alpha-hydroxynitrile glucosides) but do not give rise to hydrogen cyanide release upon hydrolysis. Structural similarities and frequent co-occurrence suggest that the biosynthetic pathways for these compounds share common features. Based on available literature data we propose that oximes produced by CYP79 orthologs are common intermediates and that their conversion into beta- and gamma-hydroxynitrile glucosides is mediated by evolutionary diversified multifunctional orthologs to CYP71E1. We designate these as CYP71(betagamma) and CYP71(alphabetagamma); in combination with the classical CYP71(alpha) (CYP71E1 and orthologs) these are able to hydroxylate any of the carbon atoms present in the amino acid and oxime derived nitriles. Subsequent dehydration reactions and hydroxylations and a final glycosylation step afford the unsaturated beta- and gamma-hydroxynitrile glucosides. This scheme would explain the distribution patterns of alpha-, beta- and gamma-hydroxynitrile glucosides found in plants. The possible biological functions of these hydroxynitriles are discussed.

Diversification of an ancient theme: hydroxynitrile glucosides

Many plants produce cyanogenic glucosides as part of their chemical defense. They are alpha-hydroxynitrile glucosides, which release toxic hydrogen cyanide (HCN) upon cleavage by endogenous plant beta-glucosidases. In addition to cyanogenic glucosides, several plant species produce beta- and gamma-hydroxynitrile glucosides. These do not release HCN upon hydrolysis by beta-glucosidases and little is known about their biosynthesis and biological significance. We have isolated three beta-hydroxynitrile glucosides, namely (2Z)-2-(beta-D-glucopyranosyloxy)but-2-enenitrile and (2R,3R)- and (2R,3S)-2-methyl-3-(beta-D-glucopyranosyloxy)butanenitrile, from leaves of Ribesuva-crispa. These compounds have not been identified previously. We show that in several species of the genera Ribes, Rhodiola and Lotus, these beta-hydroxynitrile glucosides co-occur with the L-isoleucine-derived hydroxynitrile glucosides, lotaustralin (alpha-hydroxynitrile glucoside), rhodiocyanosides A (gamma-hydroxynitrile glucoside) and D (beta-hydroxynitrile glucoside) and in some cases with sarmentosin (a hydroxylated rhodiocyanoside A). Radiolabelling experiments demonstrated that the hydroxynitrile glucosides in R. uva-crispa and Hordeum vulgare are derived from L-isoleucine and L-leucine, respectively. Metabolite profiling of the natural variation in the content of cyanogenic glucosides and beta- and gamma-hydroxynitrile glucosides in wild accessions of Lotus japonicus in combination with genetic crosses and analyses of the metabolite profile of the F2 population provided evidence that a single recessive genetic trait is most likely responsible for the presence or absence of beta- and gamma-hydroxynitrile glucosides in L. japonicus. Our findings strongly support the notion that the beta- and gamma-hydroxynitrile glucosides are produced by diversification of the cyanogenic glucoside biosynthetic pathway at the level of the nitrile intermediate.

Bioactive constituents from Chinese natural medicines. XXVI. Chemical structures and hepatoprotective effects of constituents from roots of Rhodiola sachalinensis

The methanolic extract from the roots of Rhodiola sachalinensis was found to show a protective effect on D-galactosamine-induced cytotoxicity in primary cultured mouse hepatocytes. From the methanolic extract, five new glycosides, two monoterpene glycosides, two flavonol bisdesmosides, and a cyanogenic glycoside, were isolated together with 34 known compounds. The structures of new constituents were elucidated on the basis of chemical and physicochemical evidence. In addition, the principal constituents, sachalosides III and IV, rhodiosin, and trans-caffeic acid, displayed hepatoprotective effects.

Rhodiola rosea L. extract reduces stress- and CRF-induced anorexia in rats

Rhodiola rosea L. is one of the most popular adaptogen and anti-stress plants in European and Asiatic traditional medicine. Its pharmacological properties appear to depend on its ability to modulate the activation of several components of the complex stress-response system. Exposure to both physical and psychological stress reduces feeding in rodents. The aim of this work was thus to determine whether in rats an hydroalcoholic R. rosea extract standardized in 3% rosavin and 1% salidroside (RHO) reverses hypophagia induced by (1) physical stress due to 60 min immobilization; (2) intracerebroventricular injection of corticotrophin-releasing factor (CRF, 0.2 microg/rat), the major mediator of stress responses in mammals; (3) intraperitoneal injection of Escherichia coli Lipopolysaccharide (LPS, 100 microg/kg); (4) intraperitoneal administration of fluoxetine (FLU, 8 mg/kg). The effect of the same doses of the plant extract was also tested in freely-feeding and in 20 h food-deprived rats. RHO was administered acutely by gavage to male Wistar rats 1 h before the experiments. The results show that at 15 and 20 mg/kg, RHO reversed the anorectic effects induced both by immobilization and by intracerebroventricular CRF injection. Moreover, at the same doses, RHO failed to reduce the anorectic effect induced both by LPS and FLU, and did not modify food intake in both freely-feeding and food-deprived rats. These findings strongly demonstrated that RHO is able selectively to attenuate stress-induced anorexia, providing functional evidence of claimed adaptogen and anti-stress properties of Rhodiola rosea L.

Adaptogenic and central nervous system effects of single doses of 3% rosavin and 1% salidroside Rhodiola rosea L. extract in mice

Rhodiola rosea L., or 'golden root', is a popular plant in traditional medicine in Eastern Europe and Asia, with a reputation for improving depression, enhancing work performance, eliminating fatigue and treating symptoms of asthenia subsequent to intense physical and psychological stress. Due to these therapeutic properties, R. rosea is considered to be one of the most active adaptogenic drugs. To confirm and extend results obtained in the few preclinical and clinical studies available in English language journals, the purpose of the present study was to re-investigate the effects produced by a single oral administration of an R. rosea hydroalcohol extract (containing 3% rosavin and 1% salidroside) on the central nervous system in mice. The extract was tested on antidepressant, adaptogenic, anxiolytic, nociceptive and locomotor activities at doses of 10, 15 and 20 mg/kg, using predictive behavioural tests and animal models. The results show that this R. rosea extract significantly, but not dose-dependently, induced antidepressant-like, adaptogenic, anxiolytic-like and stimulating effects in mice. This study thus provides evidence of the efficacy of R. rosea extracts after a single administration, and confirms many preclinical and clinical studies indicating the adaptogenic and stimulating effects of such R. rosea extracts. Moreover, antidepressant-like and anxiolytic-like activities of R. rosea were shown in mice for the first time.

Bioactive compounds from Rhodiola rosea (Crassulaceae)

The methanol extract of the underground part of Rhodiola rosea was found to show inhibitory activity against Staphylococcus aureus. Bioactivity-guided fractionation of a 95% ethanol extract from the stems of R. rosea led to the isolation of five compounds: gossypetin-7-O-L-rhamnopyranoside (1), rhodioflavonoside (2), gallic acid (3), trans-p-hydroxycinnamic acid (4) and p-tyrosol (5). Their structures were elucidated by UV, IR, MS and NMR data, as well as by comparison with those of the literature. Compounds 1 and 2 were evaluated for their antibacterial and antiprostate cancer cell activities. Compounds 1 and 2 exhibited activity against Staphylococcus aureus with minimum inhibitory concentrations of 50 microg/mL and 100 microg/mL, respectively. Cytotoxicity studies of 1 and 2 also displayed activity against the prostate cancer cell line with IC(50) values of 50 microg/mL and 80 microg/mL, respectively.

Zedoariae rhizoma and curcumin inhibits platelet-derived growth factor-induced proliferation of human hepatic myofibroblasts

During the course of liver fibrogenesis, hepatic myofibroblast cells (hMF), mostly derived from hepatic stellate cells (HSC), proliferate and synthesize excessive amounts of extracellular matrix (ECM) components. To evaluate the antiproliferative effect of a traditional herbal medicine, Zedoariae rhizoma water extracts (ZR) was examined on the growth inhibition of human hMF since proliferation of hMF is known to be central for the development of fibrosis during liver injury, and factors that may limit their growth are potential antifibrotic agents. The aim of this study was to test the effects of ZR on the proliferation and to clarify the molecular mechanisms of ZR inhibition of HSC proliferation in cultured human hMF. The cells were stimulated by platelet-derived growth factor (PDGF)-BB in the presence or absence of ZR. Proliferation was determined by bromodeoxy-uridine (BrdU) incorporation. The mRNA expressions of collagen alpha1(I) and (IV) were evaluated by a quantitative reverse transcription-polymerase chain reaction (RT-PCR). PDGF-receptor tyrosine phosphorylation was detected using anti-phosphotyrosine antibody. PDGF-receptor radioligand binding assay was performed by [125I]PDGF-BB. ZR inhibited the PDGF-BB-induced cell-proliferation and collagen alpha1(I) and (IV) mRNA expressions. ZR reduced the autophosphorylation of the PDGF-receptor. ZR blocked PDGF-BB binding to its receptor in a non-competitive manner. Furthermore, the 80% aqueous acetone extract of ZR was also found to show a decreasing effect against the proportion of S phase cells after PDGF stimulation. To clarify the active compounds, the principal constituents of seven sesquiterpenes (curdione, dehydrocurdione, germacrone, curcumenol, isocurcumenol, zedoarondiol and curcumenone) and a diarylheptanoid (curcumin) were examined. Among them, curcumin was found to decrease the proportion of S phase cells after PDGF stimulation at a dose of 30-50 microM. Potent antiproliferative and antifibrogenic effects of ZR toward hMF indicated that ZR might have therapeutic implications in chronic liver disease, indicating a novel role for ZR as a growth inhibitory mediator and pointing out its potential involvement in the negative regulation of liver fibrogenesis. In conclusion, ZR has an inhibitory effect on PDGF-induced proliferation of hMF and the blocking of PDGF-BB binding to its receptor may be the mechanism behind this effect.

Antiallergic activity of a disaccharide isolated fromSanguisorba of?cinalis

The antiallergic activity of the natural disaccharide, 5-O-alpha-D-(3-C-hydroxymethyl)lyxofuranosyl-beta-D-(2-C-hydroxymethyl)arabinofuranose was evaluated using both in vivo and in vitro experimental models. Intravenously administered compound inhibited the passive cutaneous anaphylaxis response in rats in a dose-dependent manner (ED(50) = 9.6 mg/kg). The compound inhibited histamine release evoked by both compound 48/80 and calcium ionophore A23187 in rat peritoneal mast cells indicating that mast cell stabilization is the major mechanism of action for its antiallergic activity. In passively sensitized isolated guinea-pig hearts, an in vitro anaphylaxis model in which histamine release plays a key role for functional deterioration, the compound markedly diminished both coronary flow reduction and histamine release on challenge to the antigen. These data demonstrate that this antiallergic natural disaccharide exerts its effect via inhibition of mast cell mediator release.

Biosynthesis of the nitrile glucosides rhodiocyanoside A and D and the cyanogenic glucosides lotaustralin and linamarin in Lotus japonicus

Lotus japonicus was shown to contain the two nitrile glucosides rhodiocyanoside A and rhodiocyanoside D as well as the cyanogenic glucosides linamarin and lotaustralin. The content of cyanogenic and nitrile glucosides in L. japonicus depends on plant developmental stage and tissue. The cyanide potential is highest in young seedlings and in apical leaves of mature plants. Roots and seeds are acyanogenic. Biosynthetic studies using radioisotopes demonstrated that lotaustralin, rhodiocyanoside A, and rhodiocyanoside D are derived from the amino acid l-Ile, whereas linamarin is derived from Val. In silico homology searches identified two cytochromes P450 designated CYP79D3 and CYP79D4 in L. japonicus. The two cytochromes P450 are 94% identical at the amino acid level and both catalyze the conversion of Val and Ile to the corresponding aldoximes in biosynthesis of cyanogenic glucosides and nitrile glucosides in L. japonicus. CYP79D3 and CYP79D4 are differentially expressed. CYP79D3 is exclusively expressed in aerial parts and CYP79D4 in roots. Recombinantly expressed CYP79D3 and CYP79D4 in yeast cells showed higher catalytic efficiency with l-Ile as substrate than with l-Val, in agreement with lotaustralin and rhodiocyanoside A and D being the major cyanogenic and nitrile glucosides in L. japonicus. Ectopic expression of CYP79D2 from cassava (Manihot esculenta Crantz.) in L. japonicus resulted in a 5- to 20-fold increase of linamarin content, whereas the relative amounts of lotaustralin and rhodiocyanoside A/D were unaltered.

Chemoenzymatic Synthesis of n-Hexyl and O-.BETA.-D-Xylopyranosyl-(1.RAR.6)-.BETA.-D-glucopyranosides

Direct beta-glucosidation between 1,6-octanediol (5) and D-glucose (3) using the immobilized beta-glucosidase (EC 3.2.1.21) from almonds with the synthetic prepolymer ENTP-4000 gave a mono-beta-glucoside (6) in 61.4% yield, which was converted into the n-hexyl beta-D-glucopyranoside (1) by means of a chemoenzymatic method. The coupling of the n-hexyl beta-D-glucopyranoside congener (13) and 2,3,4-tri-O-acetyl-beta-D-xylosyl congener (14), followed by deprotection, afforded the synthetic n-hexyl O-beta-D-xylopyranosyl-(1-->6)-beta-D-glucopyranoside (2), which was identical to the natural 2 with respect to the spectral data and specific rotation.

Phenylpropanoid glycosides from Rhodiola rosea

Rhodiola rosea L. (Golden Root) has been used for a long time as an adaptogen in Chinese traditional medicine and is reported to have many pharmacological properties. Along its known secondary metabolites tyrosol (1), salidroside (rhodioloside) (2), rosin (3), rosarin (4), rosavin (5), sachaliside 1 (6) and 4-methoxy-cinnamyl-O-beta-D-glucopyranoside (7), four compounds were isolated from aqueous methanol extract of the plant and identified as cinnamyl-(6'-O-beta-xylopyranosyl)-O-beta-glucopyranoside (8), 4-methoxy-cinnamyl-(6'-O-alpha-arabinopyranosyl)-O-beta-glucopyranoside (9), picein (10) and benzyl-O-beta-glucopyranoside (11) by UV, MS and NMR methods. Compounds 8 and 9 are new natural compounds whereas compounds 10 and 11 were isolated first time from R. rosea. Also the compounds 6 and 7 are isolated earlier only from the callus cultures of the plant but not from the differentiated plant.

Bioactive constituents of Chinese natural medicines. VII. Inhibitors of degranulation in RBL-2H3 cells and absolute stereostructures of three new diarylheptanoid glycosides from the bark of Myrica rubra

Three new diarylheptanoid glycosides, named (+)-S-myricanol 5-0-beta-D-glucopyranoside, myricanene A 5-O-alpha-L-arabinofuranosyl(1-->6)-beta-D-glucopyranoside, and myricanene B 5-0-alpha-L-arabinofuranosyl(1-->6)-beta-D-glucopyranoside, were isolated from the bark of Chinese Myrica rubra, together with twenty known compounds. The absolute stereostructures of the new diarylheptanoid glycosides were elucidated on the basis of chemical and physicochemical evidence, including the application of the modified Mosher's method. The inhibitory effects of isolated constituents on the release of beta-hexosaminidase from RBL-2H3 cells were examined, and several diarylheptanoids, myricanol, (+)-S-myricanol, myricanone, and myricanenes A and B, and a flavonol, myricetin, were found to show the inhibitory activity.