Urtica Dioica Extract Research Articles

Characterization of antioxidant and antimicrobial activities of nettle leaves (Urtica dioica L.)

Samples of stinging nettle or common nettle (Urtica dioica L.) were collected from the area of Banja Luka. To measure and evaluate the content of chlorophyll (a and b), carotenoids, and soluble proteins, as well as peroxidase activity (POD, EC 1.11.1.7.), fresh nettle leaves of different developmental stages were used. Dried nettle leaves were used to obtain ethanol extract. The dry residue of ethanol extract was dissolved in methanol and the obtained solution was used to determine the content of total phenols, flavonoids, flavonols, as well as non-enzymatic antioxidant activity and antimicrobial activity. The non-enzymatic antioxidant activity was determined by different methods: FRAP, DPPH, and ABTS. The results were compared to those of standard substances like vitamin C, BHT, and BHA. Antimicrobial activity was screened by using macrodilution method. The obtained results showed insignificantly higher content of chlorophyll, carotenoids, and proteins in young nettle leaves as well as an increase in the soluble peroxidase activities. Native electrophoresis of the soluble fraction showed the presence of two peroxidase isophorms in the soluble protein fraction of nettle leaves. The total phenolic content in nettle extracts amounted to 208.37 mg GAE/gdw, the content of total flavonoids was 20.29 mg QE/gdw, and the content of total flavonols was 22.83 mg QE/gdw. The antioxidant activity determined by FRAP method was 7.50 mM Fe(II)/gdw, whereas the antioxidant activity measured by using DPPH and ABTS methods, with IC50 values, were 31.38 and 23.55 ?g mL-1, respectively. These results showed the weak and moderate antioxidant capacity of stinging nettle. Extract of Urtica dioica L. was tested for antibacterial acivity against various Grampositive and Gram-negative bacteria: Bacillus subtilis IP 5832, Lactobacillus plantarum 299v (Lp299v), Pseudomonas aeruginosa, and Escherichia coli isolated from food and Escherichia coli isolated from urine samples. Ampicillin, erythromycin, ciprofloxacin, and gentamicin were used as positive control. The results showed that minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extract ranged from 9.05 to more than 149.93 mg mL-1.

The Effect of Hydro Alcoholic Nettle (Urtica dioica) Extract on Oxidative Stress in Patients with Type 2 Diabetes: A Randomized Double-blind Clinical Trial

Diabetes type 2 is a metabolic disorder that characterized by hyperglycemia and insulin resistance. Hyperglycemia and impairment of oxidant/antioxidant balance, can increase oxidative stress and increase risk of cardiovascular disease. In the present study, Effects of hydro alcoholic extract of Nettle on oxidative stress in type 2 diabetes were evaluated. Fifty patients (27 men, 23 women) with type 2 diabetes patients were studied. They received 100 mg kg(-1) of nettle extract of body weight hydro alcoholic for 8 weeks. At the baseline and end of 8th weeks of intervention blood levels of oxidative stress markers were measured. Data was analyzed by SPSS version 18, p < 0.05 was considered significant for all variables. After 8 weeks, Total Antioxidant Capacity (TAC) and Superoxidant Dismutase (SOD) showed a significant increase in the intervention group compared to the control group (p < 0.05). The findings showed that the hydro alcoholic extract of nettle has increasing effects on TAC and SOD in patients with type 2 diabetes without no changes in Malondialdehyde (MDA) and Glutathione Peroxides (GPX) after eight weeks intervention.

Assessment of antioxidant, antibacterial, antimycobacterial, and antifungal activities of some plants used as folk remedies in Turkey against dermatophytes and yeast-like fungi

Twenty-seven aqueous extracts obtained from 21 plants used in the treatment of respiratory tract infections as folk remedies in Turkey were investigated for their relative total phenolic contents and antioxidant, antibacterial, antimycobacterial, and antifungal activities. Antibacterial and antifungal activities against dermatophytes and yeast-like fungi were determined using the microdilution method. Antibacterial activity of all extracts was more pronounced against gram-positive bacteria than against gram-negative bacteria. These extracts also exhibited higher antifungal activity against Candida krusei than ketaconazole. Six extracts displayed antidermatophytic activity against Epidermophyton floccosum, while only 3 extracts were highly active against Trichophyton rubrum. The extracts showed strong activity against both Mycobacterium tuberculosis and Mycobacterium avium, except for the Teucrium polium, Urtica dioica, Salvia fruticosa, S. verticillata, Rosa canina (flower, shoot, and root), Rubus sanctus, and Crepis foetida extracts. Additionally, all extracts exhibited antioxidant activity in DPPH assay except for the Primula vulgaris, Ononis spinosa, Nepeta italica, Hedera helix, Lantana camara (orange flowers), U. dioica, and C. foetida extracts. The highest total phenolic content was observed in R. canina root extract. No correlation was observed between biological activities and the amount of phenolic compounds. All plants used in this study could be potential sources of new antimicrobial agents.

Metabolic effects of nettle extract in diabetes mellitus

The blood level of glucose, glycosylated hemoglobin, triglycerides, total cholesterol, summary content of very low density and low density lipoproteins, high density lipoproteins glycosylation's degree had been decreased with the nettle (Urtica dioica) extract in experimental diabetes mellitus type II in rats that was being caused with streptozotocine intraperitoneal injection and high-fat diet. The effect did not depend on food regimen during the therapy. The cholesterol atherogenic index has been decreased and the sensitivity to insulin has been recovered with the nettle extract when high-fat diet only. The level of blood glucose and glycosylated hemoglobin has been decreased with metformin when usual food regimen during the therapy. The lipid content and cholesterol atherogenic index has been normalized with metformin when both variant of diet.

New plant agents with cerebroprotective effect

The meadowsweet (Filipendula vulgaris) extract in a greater degree, than valerian extract improves in albino rat's brain the kinetic characteristics of mitochondrion respiratory activity, increases the association of substrate oxidation with ADP phosphorylation in experimental posthypoxic encephalopathy. The nettle (Urtica dioica) extract increases in albino rat's brain the rate of cycle Krebs substrate utilization and oxidative phosphorylation coupling in experimental inhibition of fatty acids p-oxidation caused with 4-pentenoic acid. The meadowsweet and nettle extracts posses the expressed antioxidant effect.

Effect of Urtica dioica L. (Urticaceae) on Testicular Tissue in STZ-induced Diabetic Rats

Urtica dioica L. (Stinging nettle) has already been known for a long time as a medicinal plant in the world. This histopathological and morphometrical study was conducted to determine the effects of the hydroalcoholic extract of Urtica dioica leaves on testis of streptozotocin-induced diabetic rats. Eighteen male Wistar rats were allocated to equally normal, diabetic and treatment groups. Hyperglycemia was induced by Streptozotocin (80 mg kg(-1)) in animals of diabetic and treatment groups. One week after STZ injection (80 mg kg(-1)), the rats of treatment group received the extract of U. dioica (100 mg/kg/day) IP for 28 days. After 5 weeks of study, all the rats were sacrificed and testes were removed and fixed in bouin and after tissue processing stained with H and E technique. Tubular cell disintegration, sertoli and spermatogonia cell vacuolization and decrease in sperm concentration in seminiferous tubules were seen in diabetic and treatment groups group in comparison with control. External Seminiferous Tubular Diameter (STD) and Seminiferous Epithelial Height (SEH) significantly reduced (p < 0.05) in the diabetic rats compared with controls and these parameters in the treatment group were similar to diabetics animals. This study showed that hydroalcoholic extract of Urtica dioica leaves, after induction of diabetes; has no treatment effect on seminiferous tubules alterations in streptozotocin-induced diabetic rats.

The Effect of Hydro Alcoholic Nettle (Urtica dioica) Extracts on Insulin Sensitivity and Some Inflammatory Indicators in Patients with Type 2 Diabetes: A Randomized Double-blind Control Trial

Type 2 diabetes is a metabolic disorder that is strongly associated with cardiovascular risk. Inflammation is a potential risk factor for cardiovascular disease. In this study, hydro alcoholic extract of Nettle (Urtica dioica) on insulin sensitivity and some inflammatory indicators in type 2 diabetic patients were studied. A randomized double-blind clinical trial on 50 men and women with type 2 diabetes was done for 8 weeks. Patients were adjusted by age, sex and duration of diabetes, then randomly divided into two groups, an intervention and control group. They received, 100 mg kg-1nettle extract or placebo in three portions a day for 8 weeks. Interleukin 6 (IL-6), Tumor Necrosis Factor-alpha (TNF-alpha), High Sensitive C-Reactive protein (hs-CRP) and Fasting Insulin concentration were measured. Insulin Sensitivity was calculated, at the beginning and the end of the study. The data were analyzed by SPSS version 18, p<0.05 was considered significant for all variables. After 8 weeks, IL-6 and hs-CRP showed a significant decrease in the intervention group compared to the control group (p<0.05). The findings showed that the hydro alcoholic extract of nettle has decreasing effects on IL-6 and hs-CRP in patients with type 2 diabetes after eight weeks intervention.

The Effect of Hydroalcholic Nettle (Urtica dioica) Extracts on Some Cardiovascular Risk Factors in Patients With Type 2 Diabetes

The Effect of Hydroalcholic Nettle (Urtica dioica) Extracts on Some Cardiovascular Risk Factors in Patients With Type 2 Diabetes

Protective role of Urtica dioica L. (Urticaceae) extract on hepatocytes morphometric changes in STZ diabetic Wistar rats

The present investigation was carried out to evaluate the protective effect of the hydroalcoholic extract of Urtica dioica leaves on the quantitative morphometric changes in the liver of streptozotocin-induced diabetic rats. Thirty male Wistar rats were divided into control (G1), diabetic (G2), diabetic + Urtica dioica (G3) groups. The control group received only sham injections of intraperitoneal saline; the diabetic group received intraperitoneal saline for 5 days followed by streptozotocin (80 mg/kg) on the 6th day; and the diabetic + Urtica dioica group received 100 mg/kg Urtica dioica intraperitoneal (7) injections for 5 days and streptozotocin injection on the 6th day. After five weeks, the animals were sacrificed and whole livers removed. Liver specimens were used for quantitative morphometric analysis after hematoxylin and eosin staining. All data were statistically analyzed by one-way ANOVA and expressed as the mean with standard error of means. In the G3 (diabetic + Urtica diocia) group, the mean surface area of hepatocytes in the periportal zone (Z1) was greater than in G2 (diabetic) and G1 (control) groups, but this difference was not significant. No alteration was observed in the surface area of hepatocytes in the perivenous zone (Z3) in the diabetic + Urtica dioica (G3) group compared to the diabetic (G2) group. The mean nuclear area of hepatocytes of the rats in the diabetic + Urtica dioica (G3) group was higher in Z1 and lower in Z3 than that of rats in the diabetic (G2) group. The mean diameter of hepatocyte nuclei in the diabetic + Urtica dioica (G3) group was lower than that of diabetic (G2) and control (G1) groups in both Z1 and Z3. This study revealed that the administration of extract of Urtica dioica leaves before induction of diabetic with streptozotocin has a protective effect on the morphometric alterations of hepatocytes in the periportal and perivenous zones of the liver lobule in rats.

Effects of water extract of Urtica dioica L. and modified atmosphere packaging on the shelf life of ground beef

Effects of lyophilized Urtica dioica L. water extract (LUWE) and modified atmosphere packaging (MAP) on the quality and shelf life of ground beef were investigated. Ground beef was stored as aerobic control, MAP (80%O(2)+20% CO(2)), MAP+250 ppm LUWE and MAP and 500 ppm LUWE at 2+/-0.5 degrees C for 14 days. MAP and LUWE had significant effects on mesophilic, psychrotrophic and lactic acid bacteria and Pseudomonas counts. Depending on the level of LUWE, Pseudomonas and psychrotrophic counts decreased. Treatment with 500 ppm LUWE+MAP showed the lowest TBARS values compared to other groups during storage. 80% O(2)-MAP increased TBARS values. Treatment had no significant effect on L* and b* values of the exterior of the ground beef, but had significant effects on the color of interior sections.

Effects of Urtica dioica extract on lipid profile in hypercholesterolemic rats

To investigate the effects of extract of Urtica dioica, a perennial herb in Iran, on lipid profile in hypercholesterolemic rats. The effects of Urtica dioica extract were tested by using it as a supplement in a high-cholesterol diet. Male rats were fed a high cholesterol diet (10 mL/kg) for 4 weeks with Urtica dioica extract (100 or 300 mg/kg) or 10 mg/kg lovastatin supplementation to study the hypocholesterolemic effects of Urtica dioica on plasma lipid levels, hepatic enzymes activities, and liver histopathological changes. Urtica dioica extract at 100 and 300 mg/kg significantly reduced the levels of total cholesterol (TC), and low-density lipoprotein-cholesterol (LDL-C) and also markedly decreased liver enzymes and weight in animals with a high cholesterol diet. Hematoxylin and eosin staining showed that in the 100 mg/kg extract of Urtica dioica group, the appearance of the liver cells was similar to the control group, and steatosis and inflammation were not found. In the 300 mg/kg extract of Urtica dioica group, mild steatosis was observed but mononuclear inflammatory infiltration was not found. The hepatic histopathological results reflect the correlation of Urtica dioica extract with both liver weight and the levels of plasma TC and LDL-C. These results indicate that Urtica dioica extract has hypocholesterolemic effects in the animal model.

Nettle extract (Urtica dioica) affects key receptors and enzymes associated with allergic rhinitis

A nettle (Urtica dioica) extract shows in vitro inhibition of several key inflammatory events that cause the symptoms of seasonal allergies. These include the antagonist and negative agonist activity against the Histamine-1 (H(1)) receptor and the inhibition of mast cell tryptase preventing degranulation and release of a host of pro-inflammatory mediators that cause the symptoms of hay fevers. The nettle extract also inhibits prostaglandin formation through inhibition of Cyclooxygenase-1 (COX-1), Cyclooxygenase-2 (COX-2), and Hematopoietic Prostaglandin D(2) synthase (HPGDS), central enzymes in pro-inflammatory pathways. The IC(50) value for histamine receptor antagonist activity was 251 (+/-13) microg mL(-1) and for the histamine receptor negative agonist activity was 193 (+/-71) microg mL(-1). The IC(50) values for inhibition of mast cell tryptase was 172 (+/-28) microg mL(-1), for COX-1 was 160 (+/-47) microg mL(-1), for COX-2 was 275 (+/-9) microg mL(-1), and for HPGDS was 295 (+/-51) microg mL(-1). Through the use of DART TOF-MS, which yields exact masses and relative abundances of compounds present in complex mixtures, bioactives have been identified in nettle that contribute to the inhibition of pro-inflammatory pathways related to allergic rhinitis. These results provide for the first time, a mechanistic understanding of the role of nettle extracts in reducing allergic and other inflammatory responses in vitro.

Contact and residual toxicities of 30 plant extracts to Colorado potato beetle larvae

Contact and residual toxicities of 30 plant extracts were investigated on third instar larvae of Colorado potato beetle, Leptinotarsa decemlineata. The plant samples were collected during the spring and summer of 2002 and were dried and ground. The plant samples were treated with methanol and the residue was eluted with distilled water containing 10% acetone, resulting in plant extracts. In contact bioassays, the beetle larvae were treated with 40% (w/w) plant extract using a Potter Spray Tower. The insects were incubated at 28±2°C under a 16 h: 8 h photo regime and the mortality was recorded at 24 h intervals for 7 days. The plant extracts exhibited varying toxicity to the larvae ranging from 0 – 91% after 24 h incubation and Artemisia vulgaris, Hedera helix, Humulus lupulus, Lolium temulentum, Rubia tinctoria, Salvia officinalis, Sambucus nigra, Urtica dioica, Verbascum songaricum, and Xanthium strumarium extracts resulted in significantly higher mortality than the control. Generally, prolonged incubation time did not result in an increase in mortality. After 48 h of incubation, 10 plant extracts yielded a significant mortality and H. lupulus extract, the most toxic extract among those tested, caused 99% mortality which is similar the mortality caused by the chemical standard, imidacloprid. In residual assays, potato leaflets were treated with 20% (w/w) plant-extract concentrations using a Potter Spray Tower. Third instar larvae were added to a glass jar to which treated leaflets were transferred before incubation at the temperature and photo regime described above. Mortality was recorded at 24 h intervals for 7 days. Five plant extracts, H. lupulus, L. temulentum, Reseda lutea and Solanum nigrum, induced significantly higher mortalities compared with controls. Chenopodium album extract was the most toxic, killing 34.9% of exposed larvae, followed by L. temulentum, H. lupulus and S. nigrum after 72 h incubation. The results exhibited that certain plant extracts were toxic to the beetle larvae and may have potential for controlling this destructive pest under field conditions.

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.

Stimulation of lymphocyte proliferation and inhibition of nitric oxide production by aqueousUrtica dioica extract

The immunomodulatory and antiinflammatory activities of aqueous Urtica dioica extract were investigated for their effect on the mitogenic response of murine splenocytes and nitric oxide production by murine peritoneal macrophages in vitro. It was found that this extract stimulated the proliferation of T-lymphocytes and suppressed NO production in lipopolysaccharide-stimulated macrophages without affecting cell viability.

Aqueous extract of urtica dioica makes significant inhibition on adenosine deaminase activity in prostate tissue from patients with prostate cancer

Aim: Investigation of possible effects of aqueous extract of urtica dioica leaves on adenosine deaminase activity in prostate tissue from patients with prostate cancer. Methods: Ten prostate tissues from patients with pathologically proven localized prostate cancer (Gleason scores 4 to 7) were used in the study. In the tissues, ADA activities with and without preincubation with different amounts of urtica dioica extracts were performed. Results: Aqueous extract of urtica dioica results in significant inhibition on adenosine deaminase (ADA) activity of prostate tissue. Conclusion: ADA inhibition by urtica dioica extract might be one of the mechanisms in the observed beneficial effect of urtica dioica in prostate cancer.

Antihyperglycemic activity of the aqueous extract of Urtica dioica

When administered 30 min before glucose loading, the aqueous extract of Urtica dioica (nettle) (250 mg/kg) showed a strong glucose lowering effect. The decrease of glycemia has reached to 33±3.4% of the control value 1 h after glucose loading. This effect was persistent during 3 h. In contrast, nettle did not show hypoglycemic effect in alloxan-induced diabetic rats. The amount of glucose absorbed in a segment jejunum in situ was 8.05±0.68 mg in presence of nettle extract vs. 11.11±0.75 mg in control rats during 2 h ( P<0.05). The results indicate that nettle has a significant antihyperglycemic effect in OGTT model. This effect may be caused in part by the reduction of intestinal glucose absorption. LD 50 is 3.5 g/kg (i.p.).

Modulatory effect of Urtica dioica L. (Urticaceae) leaf extract on biotransformation enzyme systems, antioxidant enzymes, lactate dehydrogenase and lipid peroxidation in mice.

The effects of two doses (50 and 100 mg/kg body wt given orally for 14 days) of an ethanol-water (80%-20%) extract of Urtica dioica L. and butylated hydroxyanisole (BHA) were investigated, for phase I and phase II enzymes, antioxidant enzymes, lactate dehydrogenase, lipid peroxidation and sulfhydryl groups in the liver of Swiss albino mice (8-9 weeks old). A modulatory effect of two doses and BHA was also observed for the activities of glutathione S-transferase, DT-diaphorase, superoxide dismutase and catalase in the kidney, lung and forestomach, as compared with the control group. The activities of cytochrome b5 (cyt b5), NADH-cytochrome b5 reductase (cyt b5 R), glutathione S-transferase (GST), DT-diaphorase (DTD), glutathione peroxidase (GPx), glutathione reductase (GR), superoxide dismutase (SOD) and catalase (CAT) showed a significant increase in the liver at both dose levels of extract. Both extract-treated showed significantly lower activity of cytochrome P450 (cyt P450), lactate dehydrogenase (LDH), NADPH-cytochrome P450 reductase (cyt P450 R), total sulfhydryl groups (T-SH), nonprotein sulfhydryl groups (NP-SH) and protein-bound sulfhydryl groups (PB-SH). BHA-treated Swiss albino mice showed a notable increase in levels of cyt b5, DTD, T-SH, PB-SH, GPx, GR, and SOD in the liver while, LDH, cyt P450, cyt P450 R, Cyt b5 R, GST, NP-SH, and CAT levels were reduced significantly as compared to control values. The extract was effective in inducing GST, DTD, SOD and CAT activity in the forestomach and SOD and CAT activity in the lung at both dose levels. BHA-treated Swiss albino mice induced DTD, GST and all antioxidative parameters in the kidney, lung and forestomach.

Acute diuretic, natriuretic and hypotensive effects of a continuous perfusion of aqueous extract of Urtica dioica in the rat

This study was performed on anaesthetized male Wistar rats that received a continuous intravenous perfusion during 1.25 h of an aqueous extract of aerial parts of Urtica dioica L. (Urticaceae) at a low dose of 4 mg/kg/h or at a high dose of 24 mg/kg/h, or furosemide (control diuretic) at a dose of 2 mg/kg/h. As compared with a control period in each rat, the arterial blood pressure was reduced proportionally to the dose of the perfusion of the plant extract (15 and 38%, P<0.001, respectively). These effects were accompanied by a correlative increase of diuresis (11 and 84%, P<0.001, respectively) and natriuresis (28 and 143%, P<0.001, respectively). In the rats perfused by furosemide, the arterial blood pressure was reduced by 28% ( P<0.001). The diuresis and natriuresis were also increased proportionally in this case (85 and 155%, P<0.001, respectively). Nevertheless, the hypotensive action of U. dioica was reversible during the recovery periods in about 1 h with the lower dose of the plant extract and furosemide, while the effect of the higher dose was persistent, indicating a possible toxic effect. In conclusion, the results demonstrate an acute hypotensive action of U. dioica that indicates a direct effect on the cardiovascular system. Moreover, diuretic and natriuretic effects were also observed, suggesting an action on the renal function. Finally, the plant extract seems to have a toxic effect at the higher dose.

Antiproliferative effect on human prostate cancer cells by a stinging nettle root (Urtica dioica) extract.

In the present study the activity of a 20% methanolic extract of stinging nettle roots (Urtica dioica L., Urticaceae) on the proliferative activity of human prostatic epithelial (LNCaP) and stromal (hPCPs) cells was evaluated using a colorimetric assay. A concentration-dependent and significant (p < 0.05) antiproliferative effect of the extract was observed only on LNCaP cells during 7 days, whereas stromal cell growth remained unaltered. The inhibition was time-dependent with the maximum of growth reduction (30%) at a concentration of 1.0E-6 mg/ml on day 5 compared to the untreated control. On day 4 and 6, the reduction in proliferation of LNCaP cells showed the minimal effective dose at 1.0E-9 mg/ml. No cytotoxic effect of ME-20 on cell proliferation was observed. The antiproliferative effect of ME-20 of stinging nettle roots observed both in an in vivo model and in an in vitro system clearly indicates a biologically relevant effect of compounds present in the extract.