Phenolic Profile, Antioxidant Capacity and Antimicrobial Activity of Nettle Leaves Extracts Obtained by Advanced Extraction Techniques.

Nettle is a widely known plant whose high biological activity and beneficial medicinal effects are attributed to various bioactive compounds, among which polyphenols play an important role. In order to isolate polyphenols and preserve their properties, advanced extraction techniques have been applied to overcome the drawbacks of conventional ones. Therefore, microwave-assisted extraction (MAE) has been optimized for the isolation of nettle leaves polyphenols and it was compared to pressurized liquid extraction (PLE) and conventional heat-reflux extraction (CE). The obtained extracts were analyzed for their individual phenolic profile by UPLC MS2 and for their antioxidant capacity by ORAC assay. MAE proved to be the more specific technique for the isolation of individual phenolic compounds, while PLE produced extracts with higher amount of total phenols and higher antioxidant capacity. Both techniques were more effective compared to CE. PLE nettle extract showed antimicrobial activity against bacteria, especially against Gram-negative Pseudomonas fragi ATCC 4973 and Campylobacter jejuni NCTC 11168 strains. This suggests that PLE is suitable for obtaining a nettle extract with antioxidant and antimicrobial potential, which as such has great potential for use as a value-added ingredient in the food and pharmaceutical industry.

The biological synthesis of gold/perlite nanocomposite using Urtica dioica extract and its chitosan-capped derivative for healing wounds infected with methicillin-resistant Staphylococcus aureus.

The preparation of ointments from natural compounds is essential for accelerating infected wounds. This study investigated the effects of topical uses of gold nanoparticles (Au)/perlite (Au/Perl) nanocomposites (NCs) by the help of Urtica dioica extract and its chitosan-capped derivative (Chit) on methicillin-resistant Staphylococcus aureus (MRSA)-infected wound healing in a mouse model. Furthermore, Au/Perl/Chit nanocomposite was prepared using protonated chitosan solution. The physicochemical properties of the as-synthesized nanocomposites were also investigated. The effects of Au/Perl/Chit NC were assessed by antibacterial, histopathological parameters as well as molecular evaluations. Then, they were compared with synthetic agent of mupirocin. The results revealed that Au/Perl NC was mesoporous and spherical in a range of 13-15 nm. Topical administration of Au/Perl/Chit ointment accelerated wound healing by reducing bacteria colonization and wound rate enhancing collagen biosynthesis and re-epithelialization, the expressions of IL-10, PI3K, AKT, bFGF, and COL1A genes, which is in agreement with the obtained results for mupirocin. In conclusion, the results strongly demonstrated that administration of ointments prepared from Au/Perl and Au/Perl/Chit nanocomposites stimulates MRSA-infected wound healing by decreasing the length of healing time and regulating PI3K/AKT/bFGF signaling pathway and is a promising candidate in stimulating MRSA-infected wound regeneration.

Urtica Dioica Root Extract on Clinical and Biochemical Parameters in Patients with Benign Prostatic Hyperplasia, Randomized Controlled Trial.

BACKGROUND AND OBJECTIVES: Benign Prostatic Hyperplasia (BPH) is a common urological disorder as men get older. BPH can cause uncomfortable urinary tract symptoms. Given the high incidence of the disease, further research is an undeniable necessity for its better management. In this research, the efficacy of Urtica Dioica root extract (UDE) on clinical and biochemical parameters were evaluated in this type of patients. MATERIALS AND METHODS: Participants were 60 men with BPH that randomly allocated to two equal groups (Intervention = 30 and Comparison = 30). Block balanced Randomization method was performed using a computer by a trained nurse. Intervention and comparison groups received 450 mg day-1 UDE and placebo as tablets for 12 weeks, respectively. The main outcome was changes in International Prostate Symptoms Score (IPSS) from baseline to end of treatment. Data were collected by completing a standard questionnaire and performing relevant tests based on common laboratory methods. RESULTS: UDE had an intermediate effect on IPSS, a small effect on serum high-sensitivity C-reactive protein (hs-CRP), intermediate to large effect on malondialdehyde (MDA) levels and intermediate effect on superoxide dismutase (SOD) activity. The magnitude of the effects of UDE on other parameters was overall negligible compared to the comparison and not significant. No side effects were seen in these patients following tablet usage. CONCLUSION: UDE consumption for 12 weeks among BPH patients had clinically significant effects on IPSS, serum hs-CRP, MDA and SOD activity.

Metabolomics of the alimurgic plants Taraxacum officinale, Papaver rhoeas and Urtica dioica by combined NMR and GC-MS analysis.

INTRODUCTION: The phytoalimurgic plants, common dandelion (Taraxacum officinale), corn poppy (Papaver rhoeas) and stinging nettle (Urtica dioica) are a source of nutraceuticals. OBJECTIVES: To apply a combined metabolomic fingerprinting approach by nuclear magnetic resonance (NMR) and gas chromatography-mass spectrometry (GC-MS) to common dandelion, corn poppy and stinging nettles to obtain simultaneous identification and quantitation of the major classes of organic compounds. METHODOLOGY: The whole plants collected in the Cilento National Park were dried and then extracted to obtain non-polar and polar organic extracts. GC-MS was used for non-polar extracts while 1 H-NMR spectroscopy was used for polar extracts. In both cases, simultaneous identification and quantification of the bioactive metabolites was obtained. RESULTS: Non-polar organic extracts of all plants were mainly composed of palmitic, stearic and oleic acids. The two pentacyclic triterpenols α- and ß-amyrin were detected in nettle extract. The analysis of polar organic extracts allowed to detect and quantify organic acids and sugars as main metabolites along with amino acids, caffeoyl derivatives, flavonoids, and nucleotides. In particular, corn poppy leaves contained a huge amount of glyceric acid (55.7% of the total extract). Stinging nettles, instead, exhibited a large amount of choline (19.5%). CONCLUSION: Metabolomic approach coupling GC-MS with NMR spectroscopy allowed to provide a detailed metabolite profile of three alimurgic plants, common dandelion, corn poppy and stinging nettle, from both a qualitative and quantitative point of view.

Cytotoxic effects of Urtica dioica radix on human colon (HT29) and gastric (MKN45) cancer cells mediated through oxidative and apoptotic mechanisms.

Defects in the apoptotic pathways are responsible for both the colorectal cancer pathogenesis and resistance to therapy. In this study, we examined the level of cellular oxidants, cytotoxicity and apoptosis induced by hydroalcoholic extract of U. dioica radix (0-2000 µg/mL) and oxaliplatin (0-1000 µg/mL, as positive control) in human gastric (MKN45) and colon (HT29) cancer, as well as normal human foreskin fibroblast (HFF) cells. Exposure to U. dioica or oxaliplatin showed a concentration dependent suppression in cell survival with IC50 values of 24.7, 249.9 and 857.5 µg/mL for HT29, MKN45 and HFF cells after 72 h treatment, respectively. ROS formation and lipid peroxidation were also concentration-dependently increased following treatment with U. dioica, similar to oxaliplatin. In addition, the number of apoptotic cells significantly increased concomitantly with concentration of U. dioica as compared with control cells, which is similar to oxaliplatin and serum-deprived cancer cells. In conclusion, the present study demonstrated that U. dioica inhibited proliferation of gastric and colorectal cancer cells while posing no significant toxic effect on normal cells. U. dioica not only increased levels of oxidants, but also induced concomitant increase of apoptosis. The precise signaling pathway by which U. dioica induce apoptosis needs further research.

Effect of Selected Pyrazine Derivatives on the Production of Phenolics and Rutin in Urtica dioica and Fagopyrum esculentum.

The effect of four pyrazine derivatives on the content of phenolic compounds in Urtica dioica L. and rutin in Fagopyrum esculentum Moench was studied. Pyrazine derivatives H1 and H2 were used on U. dioica, and derivatives S1 and S2 on F. esculentum, both separately and in combination with urea. The content of phenolic compounds in the stems of U. dioica after treatment with H2 at a concentration of 10(-3) M significantly increased compared with the control and to a lower concentration of the same pyrazine derivative. In the case of S1 and S2 for F. esculentum, rutin content also increased in stems, mainly after treatment together with urea. By contrast, rutin and phenolics contents in the leaves did not change in comparison with controls after application of H1, H2, S I and S2. Treatment with H1 and H2 in two chosen concentrations resulted in a significant increase in the net photosynthetic rate, transpiration rate and stomatal conductance. A slight increase in the rate of photosynthesis was observed also after application of variants of S1 and S1 with urea. Pyrazine derivatives did not show any effect on either the relative content of chlorophyll or chlorophyll fluorescence. A slight weight reduction of above ground biomass was shown only after application of Si and S2. Dark necrosis on the edges and center of the leaves was observed in all treated plants after pyrazine application. The results suggest that all the pyrazine derivatives possess herbicidal effects.

Effects of Urtica dioica dichloromethane extract on cell apoptosis and related gene expression in human breast cancer cell line (MDA-MB-468).

Breast cancer is the most common cancer among women in worldwide, especially in developing countries. Therefore, a large number of anticancer agents with herbal origins have been reported against this deadly disease. This study is the first to examine the cytotoxic and apoptotic effects of Urtica dioica in MDA-MB-468, human breast adenocarcinoma cells. The 3-(4,5-dimethylethiazol-2 yl)-2,5- diphenyltetrazolium (MTT) reduction and trypan-blue exclusion assay were performed in MDA-MB-468 cells as well as control cell line L929 to analyze the cytotoxic activity of the dichloromethane extract. In addition, Apoptosis induction of Urtica dioica on the MDA-MB-468 cells was assessed using TUNEL (terminal deoxy transferase (TdT)-mediated dUTP nick- end labeling) assay and DNA fragmentation analysis and real-time polymerase chain reaction (PCR). The results showed that the extract significantly inhibited cell growth and viability without inducing damage to normal control cells. Nuclei Staining in TUNEL and DNA fragments in DNA fragmentation assay and increase in the mRNA expression levels of caspase-3, caspase-9, decrease in the bcl2 and no significant change in the caspase-8 mRNA expression level, showed that the induction of apoptosis was the main mechanism of cell death that induce by Urtica dioica extract. Our results suggest that urtica dioica dichloromethane extract may contain potential bioactive compound(s) for the treatment of breast adenocarcinoma.

Sex-related differences in photoinhibition, photo-oxidative stress and photoprotection in stinging nettle (Urtica dioica L.) exposed to drought and nutrient deficiency.

Dimorphic plant species can show distinct nutrient needs due to sex-related differences in nutrient allocation to reproductive structures, which can potentially affect their sensitivity to photoinhibition and photo-oxidative stress. Here, we investigated sex-related differences in the extent of photo-oxidative stress in male and female individuals of U. dioica exposed to a combination of severe drought and nutrient starvation. Male and female individuals of U. dioica subject to severe drought stress were exposed to various levels of nutrient availability. First, a set of plants grown under field conditions and exposed to summer drought was used to test the effects of nutrient supply (given as NPK fertilizer). Secondly, the effects of various phosphate concentrations in the nutrient solution were tested in drought-stressed potted plants. The Fv/Fm ratio (maximum efficiency of PSII photochemistry), photoprotection capacity (levels of carotenoids, including the xanthophyll cycle, and vitamins C and E), and the extent of lipid peroxidation (hydroperoxide levels) were measured. Results showed that an application of the NPK fertilizer to the soil had a positive effect on drought-stressed plants, reducing the extent of lipid peroxidation in both males and females. P deficiency led to residual photoinhibition, as indicated by significant reductions in the Fv/Fm ratio, and enhanced lipid peroxidation in females, but not in males. We conclude that (i) increased nutrient availability in the soil can alleviate photo-oxidative stress in drought-stressed U. dioica plants, and (ii) U. dioica plants show sexual secondary dimorphism in terms of photoinhibition and photo-oxidative stress, but this is only apparent when stress infringed on plants is very severe.

The distribution of macronutrients, anti-nutrients and essential elements in nettles, Laportea peduncularis susp. peduncularis (River nettle) and Urtica dioica (Stinging nettle).

Laportea peduncularis and Urtica dioica, which are popularly known as "Nettles" belong to the plant family Urticaceae and are consumed as green vegetables or used for their medicinal benefit in many countries in Africa, Asia, Europe and America. This study aimed at investigating the effect of cooking on the macronutrient, anti-nutrient and elemental composition of L. peduncularis and U. dioica leaves. The results showed a decrease in the crude fat, ash, carbohydrate and vitamin C content with cooking, but an increase in the vitamin E content. The anti-nutrient content (cyanides, phytates and saponins) increased slightly with cooking, while the oxalate content has decreased. The concentration of essential elements in cooked L. peduncularis leaves were found to be in decreasing order of Ca > Mg > Fe > Mn > Zn > Cu > Cr > Ni > Co. Both raw and cooked leaves of nettles were found to be rich sources of macronutrients and essential elements and may be used as alternatives to commercially available nutrient supplements. Statistical analyses (principal component analysis and correlations) indicated that certain elements taken up by these plants were from common sources. Both positive and negative relationships between nutrients, anti-nutrients and elements were observed in the plant leaves.

Effect of Urtica dioica on morphometric indices of kidney in streptozotocin diabetic rats--a stereological study.

The aim of the present study was to investigate the effect of Urtica dioica on Morphometric indices of kidney in diabetic rats. Thirty male adult albino wistar rats of 125-175 g divided into control, diabetic and Urtica dioica treatment groups. In treatment Group, diabetic rats received 100 mg kg(-1) daily hydroalcoholic extract of U. dioica intraperitoneally for 4 weeks. After the animals had been sacrified, the kidneys were removed and fixed by formaldehyde, cut horizontally into 1 mm slices and processed, Stained with H and E. Stereological study performed using light microscope and the image projected on a table of olysa software. Cavalieri principle was used to estimate the volume of cortex, medulla and whole kidney. All the grouped data statistically evaluated using Student's t-test, expressed as the Mean +/- SE. Ration of kidney weight/body weight in diabetes (0.51) and diabetes-extract group (0.67) were higher then control group (0.42). Ratio of kidney volume/body weight in diabetes (350) and diabetes-extract group (348) were higher then control group (323). Volume Ratio of cortex/medulla in diabetes-extract group (1.65) was higher then control (1.34) and diabetes group (1.33). Glomerular area and diameter and proximal tubule diameter in diabetes-Extract group was higher than control and diabetes groups. This study revealed that Urtica dioica has no effect on renal morphometric indices in induced diabetic rats.

Urtica dioica agglutinin: separation, identification, and quantitation of individual isolectins by capillary electrophoresis and capillary electrophoresis-mass spectrometry.

With benign prostatic hyperplasia (BPH) being a major health problem in ageing men, alternative therapeutic approaches (e.g., with phytopharmaceuticals) are of great interest. Based on pharmacological evidences, one of the most promising options in that respect are the lectins found in Urtica dioica (stinging nettle) roots. In this study the qualitative and quantitative analysis of individual isolectins in U. dioica extracts is described, which is the first report on using capillary electrophoresis (CE) for the analysis of lectins in plant material at all. By utilizing a 200 mM sodium acetate buffer (pH 3.75) a baseline separation and determination of four closely related isolectins was feasible within 20 min in the aqueous plant extracts. The individual compounds were identified based on reference compounds as well as data obtained from CE-mass spectrometry (MS) experiments. After modifying the optimized CE conditions to 100 mM ammonium formate buffer with pH 3.75 and a voltage of 15 kV, the isolectins were clearly assignable in positive electrospray ionization (ESI) mode. The quantitative results obtained by CE (the total lectin content varied from 0 to 0.42% in the samples) were accurate (recovery rates of spiked samples between 92.5 and 96.2%), precise (relative standard deviation < 5%) and in good agreement to those obtained by High-performance liquid chromatography (HPLC). As for peak resolution, assignable compounds and required separation time the newly developed CE method was clearly advantageous over the determination achieved by LC.

The role of urtica dioica (urticaceae) in the prevention of oxidative stress caused by tourniquet application in rats.

Tourniquets are used in extremity surgery and provide a relatively bloodless field, thereby minimizing blood loss and helping identify the vital structures. However, they may cause an ischemia-reperfusion injury with potentially harmful local and systemic consequences. Many therapeutic effects such as diuretic, natriuretic, hypotensive, anti-rheumatic, anti-prostatic, and in-vitro anti-oxidant effects of the Urtica dioica (UD) have been determined. In the present study, we aimed to investigate the potential role of UD plant for prevention of oxidative stress in muscle tissues generated by tourniquet application in rats. Wistar rats were used in this study. The UD extract or 1.15% KCl aqueous solution, in which UD leaf samples were homogenized, was given to each group of eight rats once a day for 5 days through an intraesophageal canule. No treatment was applied to untreated group. Tourniquets were applied to the left posterior limb of rats for 1 or 2 h followed by a reperfusion period of 1 h. After the ischemia and reperfusion, the rats were killed with a high dose of anesthetic drug, and malonyldialdehyde (MDA) levels were measured in their tibialis anterior muscles. Basal MDA levels were obtained from tibialis anterior muscles of 8 control rats, which were not exposed to ischemia. MDA levels were lower in the UD-treated rats than those in untreated and KCl-treated rats after either 1 or 2 h of ischemia and 1 h reperfusion. These results indicate that UD has a potential antioxidant effect on ischemic muscle tissues.