Phytochemical and pharmacological investigation of Spiraea chamaedryfolia: a contribution to the chemotaxonomy of Spiraea genus.

OBJECTIVE: Diterpene alkaloids are secondary plant metabolites and chemotaxonomical markers with a strong biological activity. These compounds are characteristic for the Ranunculaceae family, while their occurrence in other taxa is rare. Several species of the Spiraea genus (Rosaceae) are examples of this rarity. Screening Spiraea species for alkaloid content is a chemotaxonomical approach to clarify the classification and phylogeny of the genus. Novel pharmacological findings make further investigations of Spiraea diterpene alkaloids promising. RESULTS: Seven Spiraea species were screened for diterpene alkaloids. Phytochemical and pharmacological investigations were performed on Spiraea chamaedryfolia, the species found to contain diterpene alkaloids. Its alkaloid-rich fractions were found to exert a remarkable xanthine-oxidase inhibitory activity and a moderate antibacterial activity. The alkaloid distribution within the root was clarified by microscopic techniques.

Investigation of Antimicrobial, Antioxidant, and Xanthine Oxidase--Inhibitory Activities of Phellinus (Agaricomycetes) Mushroom Species Native to Central Europe.

Ten representative Central European phellinoid Hymenochaetaceae species (Phellinus sensu lato) were selected to examine their potential pharmacological activity. In this study 40 organic (n-hexane, chloroform, 50% methanol) and aqueous extracts with different polarities were analyzed for their antimicrobial, antioxidant, and xanthine oxidase (XO)--inhibitory properties. Fomitiporia robusta, Fuscoporia torulosa, Phellopilus nigrolimitatus, and Porodaedalea chrysoloma showed moderate antibacterial activity; Bacillus subtilis ATCC 6633, methicillin-resistant Staphylococcus aureus ATCC 43300, and Moraxella catarrhalis ATCC 43617 were the strains most susceptible to the examined fungal species. The in vitro antioxidant and XO assays demonstrated that most of the selected species possess remarkable antioxidant and XO-inhibitory activities. The water extracts in general proved to be more active antioxidants than organic extracts. In the case of F. torulosa, Ph. Nigrolimitatus, and P. chrysoloma, the results of DPPH tests correlate well with those obtained by oxygen radical absorbance capacity tests; these mushrooms presented high antioxidant activities in both assays. Future studies involving phellinoid Hymenochaetaceae species are planned, which may furnish novel results in terms of the species' pharmacological activity and the specific compounds responsible for the observed activity.

Phytochemical investigation of Rumex thyrsiflorus Fingerh.

In the course of our pharmacological screening of Polygonaceae species occurring in the Carpathian Basin the extracts prepared from the roots of Rumex thyrsiflorus showed promising antiproliferative, xanthine oxidase inhibitory and antibacterial activities. The present work deals with the isolation of compounds from the root of the plant. After multistep separation process, four compounds were obtained from the n-hexane, chloroform and ethyl acetate soluble fractions of the methanol extract of the root. The structures of the isolated compounds were determined as 1-palmitoylglycerol, ß-sitosterol, (-)-epicatechin, and procyanidin B5.

Antibacterial screening of Rumex species native to the Carpathian Basin and bioactivity-guided isolation of compounds from Rumex aquaticus.

Plants belonging to the genus Rumex (family Polygonaceae) are used worldwide in traditional medicine for the treatment of various diseases caused by different microorganisms (e.g. bacteria-related dermatologic conditions, dysentery and enteritis). The present study focused on the antibacterial screening of Rumex species native to the Carpathian Basin, and isolation of compounds from one of the most efficient species, Rumex aquaticus. The antibacterial effects of n-hexane, chloroform and aqueous fractions of methanol extracts prepared from different parts of 14 Rumex species (R. acetosella, R. acetosa, R. alpinus, R. aquaticus, R. conglomeratus, R. crispus, R. hydrolapathum, R. obtusifolius subsp. obtusifolius, R. obtusifolius subsp. subalpinus, R. patientia, R. pulcher, R. scutatus, R. stenophyllus and R. thyrsiflorus) were investigated against Staphylococcus epidermidis, S. aureus, MRSA, Bacillus subtilis, Moraxella catarrhalis, Streptococcus pyogenes, S. pneumoniae, S. agalactiae, Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumoniae using the disc diffusion method. Mainly the n-hexane and chloroform extracts prepared from the roots of the plants displayed high antibacterial activity (inhibition zones>15mm) against one or more bacterial strains. The highly active extracts of the aerial part and root of R. aquaticus were subjected to a multistep separation procedure. 19 Compounds, among them naphthalenes (musizin, and its glucoside, torachrysone-glucoside, 2-methoxystypandrone), anthraquinones (emodin, chrysophanol, physcion, citreorosein, chrysophanol-8-O-glucoside), flavonoids (quercetin, quercetin-3,3'-dimethylether, isokaempferide, quercetin 3-O-arabinoside, quercetin 3-O-galactoside, catechin), stilbenes (resveratrol, piceid), and 1-stearoylglycerol were isolated from the plant. The antibacterial activities of isolated compounds were determined, and it was observed that especially naphthalenes exerted remarkable antibacterial effects against several bacterial strains.

Isolation of Chemical Constituents of Centaurea virgata Lam. and Xanthine Oxidase Inhibitory Activity of the Plant Extract and Compounds.

BACKGROUND: Centaurea virgata Lam. is a species widely used in the traditional medicine in Turkey for the treatment of diabetes, allergy and gastric ulcers. The rationale of its use in the therapy has not been studied previously, therefore the present work aimed at the chemicalpharmacological evaluation of the plant. OBJECTIVE: The xanthine oxidase (XO) inhibitory activity of the MeOH extract and its subextracts (n-hexane, CHCl3 and remaining MeOH-H2O) prepared from C. virgata was investigated in vitro. Moderate activity was exerted in case of the CHCl3 extract (98.9 ± 15.8 µg/mL), therefore constituents of this extract were analysed. METHOD: Different purification steps, such as VLC, CPC, PLC and crystallization were used for the isolation, and ESIMS, NMR, LC-MS and authentic standards were applied for identification of the compounds. XO inhibitory and DPPH assays were used for evaluation of the bioactivities. RESULTS: Sesquiterpenes [8α-hydroxysonchucarpolide, 8α-(3,4-dihydroxy-2-methylenebutanoyloxy)- dehydromelitensine, and cnicin], flavones (apigenin, hispidulin, salvigenin, eupatorin, 3'-methyleupatorin), and the flavonol isokaempferide were isolated from the active extract. The XO-inhibitory activity of these compounds was analyzed using allopurinol as a positive control (IC50 7.49 ± 0.29 µM). It was found that sesquiterpenes and flavonoids, containing 7- OMe group, are inactive. CONCLUSION: 7-Hydroxyflavones (apigenin and hispidulin) exerted significant XO inhibitory effect with IC50 values of 0.99 ± 0.33 µM and 4.88 ± 1.21 µM, respectively. Therefore, these compounds are responsible for the XO-inhibitory effect of the extract. The free radical scavenging activity of the isolated flavonoids was determined by DPPH assay, and it was stated that none of the compounds have substantial antioxidant activity, therefore the reduced generation of reactive oxygen species may be the consequence only of XO inhibition.

Three New Iridoid Glycosides from the Aerial Parts of Asperula involucrata.

Three new iridoid glycosides, named involucratosides A - C (1 - 3), were isolated from the H2 O subextract of crude MeOH extract prepared from the aerial parts of Asperula involucrata along with a known iridoid glycoside (adoxoside), three flavone glycosides (apigenin 7-O-ß-glucopyranoside, luteolin 7-O-ß-glucopyranoside, apigenin 7-O-rutinoside) as well as two phenolic acid derivatives (chlorogenic acid and ferulic acid 4-O-ß-glucopyranoside). Their chemical structures were established by UV, IR, 1D- (1 H, 13 C and JMOD) and 2D- (COSY, HSQC, HMBC and NOESY) NMR experiments and HR-ESI-MS. In addition, the crude extract, subextracts and isolates were evaluated for their xanthine oxidase inhibitory and antioxidant activities in in vitro tests. This is the first report on the chemical composition and bioactivities of A. involucrata.

The Genus Rumex: Review of traditional uses, phytochemistry and pharmacology.

ETHNOPHARMACOLOGICAL RELEVANCE: The approximately 200 species of the genus Rumex (sorrel, Polygonaceae) are distributed worldwide (European, Asian, African and American countries). Some species have been used traditionally as vegetables and for their medicinal properties. Based on the traditional knowledge, different phytochemical and pharmacological activities have been at the focus of research. This review aims to provide an overview of the current state of knowledge of local and traditional medical uses, chemical constituents, pharmacological activities, toxicity, and safety of Rumex species, in order to identify the therapeutic potential of Rumex species and further directions of research. MATERIALS AND METHODS: The selection of relevant data was made through a search using the keyword "Rumex" in "Scopus", "Google Scholar", "Web of Science", "PubMed", and "ScienceDirect" databases. Plant taxonomy was validated by the databases "The Plant List", and "Mansfeld's Encyclopedia". Additional information on traditional use and botany was obtained from published books and MSc dissertations. RESULTS: This review discusses the current knowledge of the chemistry, the in vitro and in vivo pharmacological studies carried out on the extracts, and the main active constituents, isolated from plants of genus Rumex. Although, there are about 200 species in this genus, most of the phytochemical and pharmacological studies were performed on up to 50 species. The aerial parts, leaves and roots of the plants are used as vegetables and for the treatment of several health disorders such as mild diabetes, constipation, infections, diarrhoea, oedema, jaundice, and as an antihypertensive, diuretic and analgesic and in case of skin, liver and gallbladder disorders, and inflammation. Many phytochemical investigations on this genus confirmed that Rumex species are rich in anthraquinones, naphthalenes, flavonoids, stilbenoids, triterpenes, carotenoids, and phenolic acids. Moreover, it draws the attention that high level of oxalic acid in some species can cause toxicity (kidney stones) if consumed large quantity. CONCLUSIONS: This review confirms that some Rumex species have emerged as a good source of the traditional medicine for treatment of inflammation, cancer and different bacterial infections and provides new insights for further promising investigations on isolated compounds, especially quercetin 3-O-glucoside, emodin, nepodin, torachrysone, and trans-resveratrol to find novel therapeutics and aid drug discovery. In addition, hepatoprotective, antiviral and antidiabetic activities should have priority in future pharmacological studies. However, for applying species to prevent or treat various diseases, additional pharmacological studies are needed to find the mechanism of actions, safety and efficacy of them before starting clinical trials.

Xanthine oxidase inhibitory activity of extracts prepared from Polygonaceae species.

The xanthine oxidase (XO) inhibitory activity of aqueous and organic extracts of 27 selected species belonging in five genera (Fallopia, Oxyria, Persicaria, Polygonum and Rumex) of the family Polygonaceae occurring in the Carpathian Basin were tested in vitro. From different plant parts (aerial parts, leaves, flowers, fruits and roots), a total of 196 extracts were prepared by subsequent extraction with methanol and hot H2O and solvent-solvent partition of the MeOH extract yielding n-hexane, chloroform and 50% MeOH subextracts. It was found that the chloroform subextracts and/or the remaining 50% MeOH extracts of Fallopia species (F. bohemica, F. japonica and F. sachalinensis), Rumex species (R. acetosa, R. acetosella, R. alpinus, R. conglomeratus, R. crispus, R. hydrolapathus, R. pulcher, R. stenophyllus, R. thyrsiflorus, R. obtusifolius subsp. subalpinus, R. patientia) and Polygonum bistorta, Polygonum hydropiper, Polygonum lapathifolium and Polygonum viviparum demonstrated the highest XO inhibitory activity (>85% inhibition) at 400 µg/mL. The IC50 values of the active extracts were also determined. On the basis of the results, these plants, and especially P. hydropiper and R. acetosella, are considered worthy of activity-guided phytochemical investigations.

Flavonoids isolated from Rumex aquaticus exhibit neuroprotective and neurorestorative properties by enhancing neurite outgrowth and synaptophysin.

There is heightened interest in the field of stroke recovery as there is need for agents that would prevent the debilitating effects of the disorder, thereby tremendously reducing the societal and economic costs associated with it. In this study, the isolation of two flavonoids--quercetin-3-O-galactoside (1) and quercetin-3-O-arabinoside (2)--from Rumex aquaticus (western dock) and their neuroprotective effects were reported in the oxygen-glucose deprivation (OGD) model of in vitro ischemia using rat pheochromocytoma (PC12) cell line. Bioassay-guided fractionation of the ethyl-acetate extract of Rumex aquaticus L. afforded the isolation of compounds 1 and 2. The structures of compounds were established on the basis of spectroscopic analyses (UV, mass spectrometry (MS) and nuclear magnetic resonance spectroscopy (NMR). Both compounds were isolated for the first time from this species. In the course of the pharmacological experiments it was detected that these flavonoids at 10 µM concentration significantly improved cell survival in the oxygen-glucose deprivation model of ischemia. Moreover, they also increased neurite outgrowth in differentiated PC12 cells subjected to ischemic insult. Investigations on the cellular mechanism for the observed effect revealed that compound 1 (10 µM) enhances the expression of synaptophysin - a marker of synapses, and an indicator of synaptic plasticity. Rapid restoration of neurological function following injury is paramount to the prevention of debilitating consequences of ischemic stroke. This combination of neuroprotection and neuritogenic potential could be particularly useful in the recovery phase of stroke.

Xanthine oxidase inhibitory activity of Hungarian wild-growing mushrooms.

Mushrooms represent a remarkable and yet largely unexplored source of new, biologically active natural products. In this work, we report on the xanthine oxidase (XO) inhibitory activity of 47 wild-growing mushrooms native to Hungary. Aqueous and organic (n-hexane, chloroform, and 50% methanol) extracts of selected mushrooms from different families were screened for their XO inhibitory activities. Among the 188 extracts investigated, the chloroform and 50% methanol fractions proved to be the most effective. Some species exhibited high inhibitory activity, e.g., Hypholoma fasciculare (IC50 =67.76 ± 11.05 µg/mL), Suillus grevillei (IC50 =13.28 ± 1.58 µg/mL), and Tricholoma populinum (IC50 =85.08 ± 15.02 µg/mL); others demonstrated moderate or weak activity. Additional studies are warranted to characterize the compounds responsible for the XO inhibitory activity of mushroom extracts.