Quantitative determination of plant phenolics in Urtica dioica extracts by high-performance liquid chromatography coupled with tandem mass spectrometric detection

The lignicolous fungus Trametes versicolor (L.) Lloyd (1920): a promising natural source of antiradical and AChE inhibitory agents

This study aimed to determine antiradical (DPPH^• and ^•OH) and acetylcholinesterase (AChE) inhibitory activities along with chemical composition of autochtonous fungal species Trametes versicolor (Serbia). A total of 38 phenolic compounds with notable presence of phenolic acids were identified using HPLC/MS-MS. Its water extract exhibited the highest antiradical activity against ^•OH (3.21 μg/mL), among the rest due to the presence of gallic, p-coumaric and caffeic acids. At the concentration of 100 μg/mL, the same extract displayed a profound AChE inhibitory activity (60.53%) in liquid, compared to donepezil (89.05%), a drug in clinical practice used as positive control. The flavonoids baicalein and quercetin may be responsible compounds for the AChE inhibitory activity observed. These findings have demonstrated considerable potential of T. versicolor water extract as a natural source of antioxidant(s) and/or AChE inhibitor(s) to be eventually used as drug-like compounds or food supplements in the treatment of Alzheimer’s disease.

Evaluation of the quality of herbal teas by DART/TOF-MS

The paper focuses on the optimization, settings and validation of direct analysis in real time coupled with time-of-flight detector when used for the evaluation of the quality of selected herbal teas (fennel, chamomile, nettle, linden, peppermint, thyme, lemon balm, marigold, sage, rose hip and St. John's wort). The ionization mode, the optimal ionization temperature and the type of solvent for sample extraction were optimized. The characteristic compounds of the analysed herbal teas (glycosides, flavonoids and phenolic and terpenic substances, such as chamazulene, anethole, menthol, thymol, salviol and hypericin) were detected. The obtained mass spectra were evaluated by multidimensional chemometric methods, such as cluster analysis, linear discriminate analysis and principal component analysis. The chemometric methods showed that the single variety herbal teas were grouped according to their taxonomic affiliation. The developed method is suitable for quick identification of herbs and can be potentially used for assessing the quality and authenticity of herbal teas. Direct analysis in real time/time-of-flight-MS is also suitable for the evaluation of selected substances contained in the mentioned herbs and herbal products. Copyright © 2017 John Wiley & Sons, Ltd.

A comparative overview of antioxidative properties and phenolic profiles of different fungal origins: fruiting bodies and submerged cultures of Coprinus comatus and Coprinellus truncorum

Bioactive properties of fungi considerably differ between the fruiting body (FB) and the submerged culture as regards mycelia (M) and the fermentation broth (F). Antioxidant properties of hot-water extracts obtained from three different fungal origins: FB, M and F of two autochthonous fungal species (Northern Serbia), Coprinus comatus and Coprinellus truncorum were investigated. Free radical scavenging capacity (RSC) was evaluated in vitro by the DPPH assay and reducing power ability (FRAP assay). Considering possible bioactive properties of different compounds present in fungal extracts, the content of total proteins (TP), phenols (TC) and flavonoids (TF) were investigated colorimetrically. The chemical characterisation of the examined extracts was evaluated using the HPLC-MS/MS method. C. comatus showed the strongest RSC activity; more precisely, fermentation broth extract (FCc) on DPPH radicals (IC50 = 5.06 μg mL^-1) and fruiting body extract (FBCc) for the FRAP assay (42.86 mg ascorbic acid equivalents (AAE)/g). Submerged M extract of both species showed the highest TC (MCc 81.95 mg gallic acid eq (GAE)/g d.w.; MCt 81.64 mg GAE/g d.w.), while FB extracts contained the highest content of TP. Comparing LC-MS phenolic profiles between species-interspecifically and among different fungal origins-intraspecifically (fruiting bodies and submerged cultures), high variations were noticed. In submerged M or F extracts of C. comatus, vanillic, gallic, gentisic and cinnamic acids were detected, as opposed to FB. Considering that diverse phenolic profiles of detected antioxidant compounds were obtained by submerged cultivation, this type of cultivation is promising for the production of antioxidant substances.

Prevention of polymicrobial biofilms composed of Pseudomonas aeruginosa and pathogenic fungi by essential oils from selected Citrus species

Mixed microbial infections caused by Pseudomonas aeruginosa and pathogenic fungi are commonly found in patients with chronic infections and constitute a significant health care burden. The aim of this study was to address the potential polymicrobial antibiofilm activity of pompia and grapefruit essential oils (EOs). The mechanism of antimicrobial activity of EOs was analysed. EOs of pompia and grapefruit inhibited fungal growth with MIC concentrations between 50 and 250 mg L^-1, whereas no effect on P. aeruginosa growth was observed. Both citrus EOs inhibited formation of bacterial and fungal monomicrobial biofilms in concentrations of 50 mg L^-1 and were efficient in potentiating the activity of clinically used antimicrobials in vitro The concentration of 10 mg L^-1 EOs inhibited mixed biofilm formation composed of P. aeruginosa and Aspergillus fumigatus or Scedosporium apiospermum Citrus EOs affected quorum sensing in P. aeruginosa and caused fast permeabilisation of Candida albicans membrane. Pompia and grapefruit EOs potently inhibited biofilm formation and could be used for the control of common polymicrobial infections.

Urtica dioica leaves modulates hippocampal smoothened-glioma associated oncogene-1 pathway and cognitive dysfunction in chronically stressed mice

The present study was aimed to evaluate the effect of Urtica dioica (UD) extract against chronic unpredictable stress (CUS)-induced associative memory dysfunction and attempted to explore the possible mechanism. Male Swiss albino mice (25-30g) were divided into six groups, viz. group-I received 0.3% carboxymethyl cellulose and served as control (CTRL), group II was exposed to CUS (21days) and received vehicle (CUS), group III was subjected to CUS and received Hypericum perforatum extract (350mg/kg, p.o.) (CUS+HYP), group IV received Hypericum perforatum extract (350mg/kg, p.o.) (CTRL+HYP); group V was subjected to CUS and received UD extract (50mg/kg, p.o.) (CUS+UD), group VI received UD extract (50mg/kg, p.o.) (CTRL+UD). CUS significantly induced body weight loss (p<0.05) and associative memory impairment in step down task (p<0.05) as compared to control mice. CUS significantly downregulated Smo (p<0.05), Gli1 (p<0.01), cyclin D1 (p<0.05), BDNF (p<0.01), TrKB (p<0.01) and MAPK1 (p<0.01) mRNA expression in hippocampus as compared to control mice. CUS significantly increased the levels of TBARS (p<0.01) and nitric oxide (p<0.001), and decreased catalase (p<0.001) and total thiol (p<0.01) in plasma resulting in oxidative stress and inflammation. Chronic UD administration significantly reverted CUS mediated body weight loss (p<0.05) and cognitive impairment (p<0.05). UD administration significantly decreased the levels of TBARS (p<0.01) and nitric oxide (p<0.05), and increased the levels of catalase (p<0.01) and total thiol (p<0.05) in plasma. Chronic UD administration significantly upregulated hippocampal Smo (p<0.05), Gli1 (p<0.001), cyclin D1 (p<0.05), BDNF (p<0.05), TrKB (p<0.05) and MAPK1 (p<0.05) in stressed mice. Further, UD extract did not reverse cyclopamine induced downregulation of Gli1 and Ptch1 mRNA in hippocampal slices. UD modulated Smo-Gli1 pathway in the hippocampus as well as exerted anti-inflammatory and antioxidant effects. UD extract might prove to be effective for stress mediated neurological disorders.

Urtica dioica modulates hippocampal insulin signaling and recognition memory deficit in streptozotocin induced diabetic mice

Diabetes mellitus has been associated with functional abnormalities in the hippocampus and performance of cognitive function. Urtica dioica (UD) has been used in the treatment of diabetes. In our previous report we observed that UD extract attenuate diabetes mediated associative and spatial memory dysfunction. The present study aimed to evaluate the effect of UD extract on mouse model of diabetes-induced recognition memory deficit and explore the possible mechanism behind it. Streptozotocin (STZ) (50 mg/kg, i.p. consecutively for 5 days) was used to induce diabetes followed by UD extract (50 mg/kg, oral) or rosiglitazone (ROSI) (5 mg/kg, oral) administration for 8 weeks. STZ induced diabetic mice showed significant decrease in hippocampal insulin signaling and translocation of glucose transporter type 4 (GLUT4) to neuronal membrane resulting in cognitive dysfunction and hypolocomotion. UD treatment effectively improved hippocampal insulin signaling, glucose tolerance and recognition memory performance in diabetic mice, which was comparable to ROSI. Further, diabetes mediated oxidative stress and inflammation was reversed by chronic UD or ROSI administration. UD leaves extract acts via insulin signaling pathway and might prove to be effective for the diabetes mediated central nervous system complications.

Comparison of nutritional properties of Stinging nettle (Urtica dioica) flour with wheat and barley flours

Stinging nettle (Urtica dioica. L) is a wild, unique herbaceous perennial flowering plant with Stinging hairs. It has a long history of use as a food sources as a soup or curries, and also used as a fiber as well as a medicinal herb. The current aim was to analyze the composition and bioactive compounds in Nepalese Stinging nettle. Chemical analysis showed the relatively higher level of crude protein (33.8%), crude fiber (9.1%), crude fat (3.6%), total ash (16.2%), carbohydrate (37.4%), and relatively lower energy value (307 kcal/100 g) as compared to wheat and barley flours. Analysis of nettle powder showed significantly higher level of bioactive compounds: phenolic compounds as 129 mg Gallic acid equivalent/g; carotenoid level 3497 μg/g; tannin 0.93 mg/100 g; anti-oxidant activity 66.3 DPPH inhibition (%), as compared to wheat and barley. This study further established that nettle plants as very good source of energy, proteins, high fiber, and a range of health benefitting bioactive compounds.

Comparative study of biological activities and phytochemical composition of two rose hips and their preserves: Rosa canina L. and Rosa arvensis Huds

The aim of this study was to compare phenolic profile, vitamin C content, antioxidant, anti-inflammatory and cytotoxic activity of rose hips and the preserves (purée and jam) of two Rosa species: renowned Rosa canina L. and unexplored Rosa arvensis Huds. The liquid chromatography-tandem mass spectrometry analysis of 45 phenolics resulted in quantification of 14 compounds, with quercitrin, gallic and protocatechuic acids as the most dominant. High antioxidant potential of R. canina and a moderate activity of R. arvensis extracts were determined through several assays. Purée of both species and methanol extract of air-dried R. canina hips showed some anti-inflammatory (cyclooxygenase-1 and 12-lipooxygense inhibition potency) activity. Purée of R. canina exerted cytotoxic activity only against the HeLa cell line among several others (HeLa, MCF7, HT-29 and MRC-5). The presented results support traditional use of rose hips and their fruit preserves as food with health and nutritional benefits.

The level of elements and antioxidant activity of commercial dietary supplement formulations based on edible mushrooms

Commercial preparations of Cordyceps sinensis, Ganoderma lucidum and Coprinus comatus mushroom marketed as healthy food supplements in Serbia were analyzed by atomic absorption spectrometry with a graphite furnace (GFAAS) for their element content. Antioxidant activity potential and total phenolics of the same mushrooms were determined. The element content of mushroom samples was in the range of 0.130-0.360 mg kg(-1) for lead (Pb), <0.03-0.46 mg kg(-1) for arsenic (As), 0.09-0.39 mg kg(-1) for cadmium (Cd), 98.14-989.18 mg kg(-1) for iron (Fe), 0.10-101.32 mg kg(-1) for nickel (Ni), 5.06-26.50 mg kg(-1) for copper (Cu), 0.20-0.70 mg kg(-1) for cobalt (Co), 1.74-136.33 mg kg(-1) for chromium (Cr) and 2.19-21.54 mg kg(-1) for manganese (Mn). In the tests for measuring the antioxidant activity, the methanolic extract of C. sinensis showed the best properties. The same was seen for the analysis of selected phenolic compounds; C. sinensis was found to have the highest content. Commercial preparations of C. sinensis and C. comatus can be considered to be safe and suitable food supplements included in well-balanced diets.

Urtica dioica leaves modulates muscarinic cholinergic system in the hippocampus of streptozotocin-induced diabetic mice

Diabetes mellitus is a chronic metabolic disorder and has been associated with cognitive dysfunction. In our earlier study, chronic Urtica dioica (UD) treatment significantly ameliorated diabetes induced associative and spatial memory deficit in mice. The present study was designed to explore the effect of UD leaves extract on muscarinic cholinergic system, which has long been known to be involved in cognition. Streptozotocin (STZ) (50 mg/kg, i.p., consecutively for 5 days) was used to induce diabetes followed by treatment with UD extract (50 mg/kg, oral) or rosiglitazone (5 mg/kg, oral) for 8 weeks. STZ-induced diabetic mice showed significant reduction in hippocampal muscarinic acetylcholine receptor-1 and choline acetyltransferase expressions. Chronic diabetes significantly up-regulated the protein expression of acetylcholinesterase associated with oxidative stress in hippocampus. Besides, STZ-induced diabetic mice showed hypolocomotion with up-regulation of muscarinic acetylcholine receptor-4 expression in striatum. Chronic UD treatment significantly attenuated the cholinergic dysfunction and oxidative stress in the hippocampus of diabetic mice. UD had no effect on locomotor activity and muscarinic acetylcholine receptor-4 expression in striatum. In conclusion, UD leaves extract has potential to reverse diabetes mediated alteration in muscarinic cholinergic system in hippocampus and thereby improve memory functions.