Phytochemical, Anti-diabetic and Cardiovascular Properties of Urtica dioica L. (Urticaceae): A Review

Antidiabetic Properties of Caffeoylmalic Acid, a Bioactive Natural Compound Isolated from Urtica dioica

The uncontrolled hyperglycemia that characterizes diabetes mellitus (DM) causes several complications in the organism. DM is among the major causes of deaths, and the limited efficacy of current treatments push the search for novel drug candidates, also among natural compounds. We focused our attention on caffeoylmalic acid, a phenolic derivative extracted from Urtica dioica, a plant investigated for its potential against type 2 DM. This compound was tested for its antidiabetic activity in vitro through a glucose uptake assay, in vivo in a mouse DM model and through molecular docking towards α-amylase and α-glucosidase. The effects on glucose blood level, liver enzymes, insulin and creatinine levels as well as on lipid and blood parameters, considered biochemical markers of diabetes, were also evaluated. The results showed an antidiabetic activity in vitro and in vivo, as the compound stimulates glucose absorbtion and reduces blood glucose levels. Moreover, it ameliorates lipid profile, liver and blood parameters, with moderate effect on insulin secretion. Taken together, these findings pave the way for the compounds from this class of caffeoylmalic acid as potential antidiabetic compounds.

Chamomile and Urtica dioica extracts improve immunological and histological alterations associated with polycystic ovarian syndrome in DHEA -induced mice

BACKGROUND

One of the novel mechanisms in the pathogenesis of Polycystic ovary syndrome (PCOS) is low-grade chronic inflammation. Chamomile (Matricaria recutita L.) and Nettle (Urtica dioica), with phytoestrogenic and antioxidant properties, are traditionally used to treat gynecological diseases. This study investigated the immune-modulating effects of these two plants.

METHODS

Following the induction of PCOS by subcutaneous injection (SC) of Dehydroepiandrosterone (DHEA) in BALB / C mice. Mice were treated in five groups: Sham, PCOS, PCOS + Chamomile, PCOS + Nettle, and PCOS + Chamomile and Nettle for 21 days. Ovarian morphology, blood antioxidant capacity, the abundance of Treg cells, and expression of matrix metalloproteinase-9 (MMP-9), transforming growth factor-ß (TGF-ß), cyclooxygenase-2 genes (COX-2), and tumor necrosis factor-alpha (TNF-α) were measured.

RESULTS

Folliculogenesis, Cystic follicles, and corpus luteum improved in the treatment groups (P < 0. 05). Treg cells in the DHEA group were significantly reduced compared to the Sham group (P < 0. 01). However, this decrease was not corrected in treatment groups (P > 0. 05). Total serum antioxidant capacity was significantly increased in the treatment group of Nettle and Chamomile + Nettle (P < 0. 05). The expression of MMP9 and TGFβ genes in the PCOS group was significantly higher than the Sham group (P < 0. 05), which the expression of MMP9 was corrected by treatment with Chamomile + Nettle extract (P < 0. 05).

CONCLUSION

Chamomile and Nettle extract may be an effective supplement in improving the histological and immunological changes of PCOS. However, more research is needed to confirm its effectiveness in humans.

Antioxidant Activity of Urtica dioica: An Important Property Contributing to Multiple Biological Activities

Urtica dioica (UD) is a multi-functional plant known to be used as both food and medicine from ancient times. The plant has the potential to be used as a fertilizer and for biological pest control. It is also used in textile and related industries for its quality fibers. In the recent past, the plant has received great attention for its numerous important biological activities and food applications. The antioxidant activity of UD is the crucial factor supporting its important biological activities, such as anticancer, antidiabetic and anti-inflammatory properties. The antioxidant activity of UD is also found to be protective in different organs, including the brain, liver, lungs, kidney, ovary, and uterus, and may also be protective against diseases associated with these organs. Few clinical studies have endorsed the antioxidant potential of UD in patients. The current work is an attempt to comprehensively compile and discuss the antioxidant activity of UD from in vitro, in vivo and human studies. The insights of the current study would be helpful in getting a panoramic view of the antioxidant potential of UD, and provide direction for optimizing and developing it for therapeutic applications against important diseases and conditions in the near future.

Hydroethanolic Extract of Urtica dioica L. (Stinging Nettle) Leaves as Disaccharidase Inhibitor and Glucose Transport in Caco-2 Hinderer

Herbal treatment for diabetes mellitus is widely used. The pharmacological activity is thought to be due to the phenolic compounds found in the plant leaves. The present study aims to investigate the phytochemical composition of Urtica dioica (UD) hydroethanolic extract and to screen its antidiabetic activity by disaccharidase hindering and glucose transport in Caco-2 cells. The results have shown that a total of 13 phenolic compounds in this work, viz. caffeic and coumaric acid esters (1, 2, 4-7, 10), ferulic derivative (3), and flavonoid glycosides (8, 9, 11-13), were identified using HPLC-DAD-ESI/MS². The most abundant phenolic compounds were 8 (rutin) followed by 6 (caffeoylquinic acid III). Less predominant compounds were 4 (caffeoylquinic acid II) and 11 (kaempferol-O-rutinoside). The UD hydroethanolic extract showed 56%, 45%, and 28% (1.0 mg/mL) inhibition level for maltase, sucrase, and lactase, respectively. On the other hand, glucose transport was 1.48 times less at 1.0 mg/mL UD extract compared with the control containing no UD extract. The results confirmed that U. dioica is a potential antidiabetic herb having both anti-disaccharidase and glucose transport inhibitory properties, which explained the use of UD in traditional medicine.

Evidence-Based Anti-Diabetic Properties of Plant from the Occitan Valleys of the Piedmont Alps

Data on urban and rural diabetes prevalence ratios show a significantly lower presence of diabetes in rural areas. Several bioactive compounds of plant origin are known to exert anti-diabetic properties. Interestingly, most of them naturally occur in different plants present in mountainous areas and are linked to traditions of herbal use. This review will aim to evaluate the last 10 years of evidence-based data on the potential anti-diabetic properties of 9 plants used in the Piedmont Alps (North-Western Italy) and identified through an ethnobotanical approach, based on the Occitan language minority of the Cuneo province (Sambucus nigra L., Achillea millefolium L., Cornus mas L., Vaccinium myrtillus L., Fragaria vesca L., Rosa canina L., Rubus idaeus L., Rubus fruticosus/ulmifolius L., Urtica dioica L.), where there is a long history of herbal remedies. The mechanism underlying the anti-hyperglycemic effects and the clinical evidence available are discussed. Overall, this review points to the possible use of these plants as preventive or add-on therapy in treating diabetes. However, studies of a single variety grown in the geographical area, with strict standardization and titration of all the active ingredients, are warranted before applying the WHO strategy 2014-2023.

Exotic Medicinal Plants Used in Brazil with Diuretic Properties: A Review

Several exotic plants (non-native) are used in Brazilian traditional medicine and are known worldwide for their possible diuretic actions. Among the wide variety of plants, standing out Achillea millefolium L., Camellia sinensis L. Kuntze, Crocus sativus L., Hibiscus sabdariffa Linn., Petroselinum crispum (Mill.) A.W. Hill, Taraxacum officinale (L.) Weber, and Urtica dioica L., whose effects have already been the subject of some scientific study. In addition, we also discussed other exotic species in Brazil used popularly, but that still lack scientific studies, like the species Arctium lappa L., Carica papaya L., Catharanthus roseus (L.) G. Don, Centella asiatica (L.) Urb, Citrus aurantium L., and Persea americana Mill. However, generally, clinical studies on these plants are scarce. In this context, different plant species can be designated for further comprehensive studies, therefore, promoting support for developing an effective medicine to induce diuresis.

Botanical Drugs in Traditional Chinese Medicine With Wound Healing Properties

Chronic and unhealed wound is a serious public problem, which brings severe economic burdens and psychological pressure to patients. Various botanical drugs in traditional Chinese medicine have been used for the treatment of wounds since ancient time. Nowadays, multiple wound healing therapeutics derived from botanical drugs are commercially available worldwide. An increasing number of investigations have been conducted to elucidate the wound healing activities and the potential mechanisms of botanical drugs in recent years. The aim of this review is to summarize the botanical drugs in traditional Chinese medicine with wound healing properties and the underlying mechanisms of them, which can contribute to the research of wound healing and drug development. Taken together, five botanical drugs that have been developed into commercially available products, and 24 botanical drugs with excellent wound healing activities and several multiherbal preparations are reviewed in this article.

A review of the effects of Urtica dioica (nettle) in metabolic syndrome

Metabolic syndrome is a serious health condition, yet a common worldwide disorder. It includes several risk factors such as hypertension, dyslipidemia, and high glucose levels which lead the patients to higher risks of cardiovascular diseases, diabetes, and stroke. Phytotherapy plays an important role in treating components of metabolic syndrome. Nettle (Urtica dioica) is considered a valuable plant due to bioactive compounds such as formic acid and rich sources of flavonoids. To acknowledge the role of nettle in metabolic syndrome, several mechanisms have been suggested such as alterations in potassium and calcium channels which improve hypertension. Antihyperlipidemic properties of nettle are mediated by inhibition of HMGCoA reductase and amelioration of lipid peroxidation via antioxidant effects. Also, one of the flavonoids in nettle, quercetin, is responsible for decreasing total cholesterol. Moreover, nettle is responsible for anti-diabetic effects through processes such as increasing insulin secretion and proliferation of pancreatic β-cells. This review aims to gather different studies to confirm the potential efficacy of nettle in metabolic syndrome.

Potential clinical applications of phytopharmaceuticals for the in-patient management of coagulopathies in COVID-19

Thrombotic complications occur in many cardiovascular pathologies and have been demonstrated in COVID‐19. The currently used antithrombotic drugs are not free of adverse reactions, and COVID‐19 patients in particular, when treated with a therapeutic dose of an anticoagulant do not receive mortality benefits. The clinical management of COVID‐19 is one of the most difficult tasks for clinicians, and the search for safe, potent, and effective antithrombotic drugs may benefit from exploring naturally bioactive molecules from plant sources. This review describes recent advances in understanding the antithrombotic potential of herbal drug prototypes and points to their future clinical use as potent antithrombotic drugs. Although natural products are perceived to be safe, their clinical and therapeutic applications are not always apparent or accepted. More in‐depth studies are necessary to demonstrate the clinical usefulness of plant‐derived, bioactive compounds. In addition, holistic approaches in systematic investigations and the identification of antithrombotic mechanisms of the herbal bioactive molecule(s) need to be conducted in pre‐clinical studies. Moreover, rigorous studies are needed to compare the potency of herbal drugs to that of competitor chemical antithrombotic drugs, and to examine their interactions with Western antithrombotic medicines. We have also proposed a road map to improve the commercialization of phytopharmaceuticals.

Alpinetin: A Review of Its Pharmacology and Pharmacokinetics

Flavonoids isolated from medicinal herbs have been utilized as valuable health-care agents due to their virous biological applications. Alpinetin is a natural flavonoid that emerges in many widely used medicinal plants, and has been frequently applied in Chinese patent drugs. Accumulated evidence has demonstrated that alpinetin possesses a broad range of pharmacological activities such as antitumor, antiinflammation, hepatoprotective, cardiovascular protective, lung protective, antibacterial, antiviral, neuroprotective, and other properties through regulating multiple signaling pathways with low systemic toxicity. However, pharmacokinetic studies have documented that alpinetin may have poor oral bioavailability correlated to its extensive glucuronidation. Currently, the reported pharmacological properties and pharmacokinetics profiles of alpinetin are rare to be scientifically reviewed. In this article, we aimed to highlight the mechanisms of action of alpinetin in various diseases to strongly support its curative potentials for prospective clinical applications. We also summarized the pharmacokinetics properties and proposed some viable strategies to convey an appreciable reference for future advances of alpinetin in drug development.

Strengthening of Traditional Chinese Medicine in the Health System Reform: Effect on Health Outcomes and Financial Protection

BACKGROUND

The challenges of modern medicine in addressing chronic diseases necessitate a shift of attention towards traditional medicine (TM) and other supplementary care systems. China has prioritized the strengthening of traditional Chinese medicine (TCM) in the health system reform since 2009. This study sought to assess the effects of the reform on TCM and the resultant effect of a strengthened TCM on health outcomes and financial protection.

METHODS

Longitudinal data were obtained from the China Statistical Yearbook, China Health Statistical Yearbook, China Population Statistical Yearbook, and Statistical Extract of Traditional Chinese Medicine in 31 provinces of mainland China between 2002 and 2016. Dependent variables included health outcomes measured by age-standardized excess mortality and life expectancy at birth and financial protection measured by the proportion of health expenses in total consumption expenses. The independent variables consisted of the number and proportion of TCM physicians. The fixed effects (FEs) models were established to identify the effect of the independent variables on outcomes.

RESULTS

From 2009 to 2016, the number and proportion of TCM physicians increased from 22 to 36 physicians per 100,000 population and from <12% to >15%, respectively. The changes were more rapid and higher than that in the period before the reform. An increase of 1 TCM physician per 100,000 population was associated with a decrease of 1.944 excess deaths, a 5.84-day increase in male life expectancy, and a decrease of 0.051% of health expenses among both urban and rural residents. An increase in proportion of 1% of TCM physicians was associated with a decrease of 5.097 excess deaths, a 17.52-day increase of life expectancy (both genders), an increase of 21.535-day in life expectancy (males) per 100,000 population, and a decrease of 0.082% of health expenses among rural residents.

CONCLUSION

During China's health system reform, the increased physician number has strengthened TCM. Higher TCM physician supply was associated with improved health outcomes and financial protection, which implies that the reform may have important implications on health system performance in China.

An Insight into Phytochemical, Pharmacological, and Nutritional Properties of Arbutus unedo L. from Morocco

Arbutus unedo L. (Ericaceae) is an evergreen shrub widely distributed in the Mediterranean region, particularly through the Moroccan forests. It is an important medicinal plant of great scientific interest due to its nutritional, pharmacological, and chemical properties. The objective of this review is to provide insights into traditional medicinal uses and phytochemical and pharmacological properties of A. unedo from Morocco. In Morocco, the plant has been used as a traditional medicine to treat several pathological conditions. Many phytochemical compounds have been reported in the plant, of which vitamins, carotenoids, flavonoids, polyphenols, tannins, and their derivatives are the most prevalent. Leaves and fruits of A. unedo contain the most significant number of phytochemicals among the species. Furthermore, researchers have demonstrated that A. unedo exhibited antioxidant, anticancer, antibacterial, antidiabetic, antiaggregant, and antihypertensive activities due to the presence of many biochemical compounds with health-promoting properties. According to different toxicity tests, the use of A. unedo is devoid of any significant side effects and/or toxicity. Despite its nutraceutical and health-promoting properties, Moroccan A. unedo remains underexploited mainly, and most of its traditional uses have not yet undergone scientific evidence-based research; therefore, improved knowledge about the potential value of the plant would allow understanding of its biological activity based on its phytochemical compounds that may contribute to the species preservation and valorization.

Effects of Urtica dioica on Metabolic Profiles in Type 2 Diabetes: A Systematic Review and Meta-Analysis of Clinical Trials

BACKGROUND

Several studies have investigated the effect of Urtica dioica (UD) consumption on metabolic profiles in patients with type 2 diabetes mellitus (T2DM); however, the findings are inconsistent. This systematic review and meta-analysis of clinical trials was performed to summarize the evidence of the effects of UD consumption on metabolic profiles in patients with T2DM.

METHODS

Eligible studies were retrieved from searches of PubMed, Embase, Scopus, Web of Science, Cochrane Library and Google Scholar databases until December 2019. Cochran (Q) and I-square statistics were used to examine heterogeneity across included clinical trials. Data were pooled by using fixed-effect or random-effects model and expressed as weighted mean difference (WMD) and 95% confidence interval (CI).

RESULTS

Among 1485 citations, thirteen clinical trials were found to be eligible for the current meta-analysis. UD consumption significantly decreased levels of fasting blood glucose (FBG) (WMD= -17.17 mg/dl, 95% CI: -26.60, -7.73, I2= 93.2%), hemoglobin A1c (HbA1c) (WMD= -0.93, 95% CI: -1.66, -0.17, I2= 75.0%), C-reactive protein (CRP) (WMD= -1.09 mg/dl, 95% CI: -1.64, -0.53, I2= 0.0%), triglycerides (WMD = -26.94 mg/dl, 95 % CI = [-52.07, -1.82], P = 0.03, I2 = 90.0%), systolic blood pressure (SBP) (WMD= -5.03 mmHg, 95% CI = -8.15, -1.91, I2= 0.0%) in comparison to the control groups. UD consumption did not significantly change serum levels of insulin (WMD= 1.07 μU/ml, 95% CI: -1.59, 3.73, I2= 63.5%), total-cholesterol (WMD= -6.39 mg/dl, 95% CI: -13.84, 1.05, I2= 0.0%), LDL-cholesterol (LDL-C) (WMD= -1.30 mg/dl, 95% CI: -9.95, 7.35, I2= 66.1%), HDL-cholesterol (HDL-C) (WMD= 6.95 mg/dl, 95% CI: -0.14, 14.03, I2= 95.4%), body max index (BMI) (WMD= -0.16 kg/m2, 95% CI: -1.77, 1.44, I2= 0.0%), and diastolic blood pressure (DBP) (WMD= -1.35 mmHg, 95% CI: -2.86, 0.17, I2= 0.0%) among patients with T2DM.

CONCLUSION

UD consumption may result in an improvement in levels of FBS, HbA1c, CRP, triglycerides and SBP, but did not affect on levels of insulin, total-, LDL-, and HDL-cholesterol, BMI, and DBP in patients with T2DM.

Bioactive Foods and Medicinal Plants for Cardiovascular Complications of Type II Diabetes: Current Clinical Evidence and Future Perspectives

Cardiovascular diseases (CVDs) are the main cause of mortality in type 2 diabetes mellitus (T2DM); however, not all patients are fully satisfied with the current available treatments. Medicinal plants have been globally investigated regarding their effect in CVD, yet the field is far from getting exhausted. The current paper aims to provide an evidence-based review on the clinically evaluated medicinal plants and their main therapeutic targets for the management of CVD in T2DM. Electronic databases including PubMed, Cochrane, Embase, Scopus, and Web of Science were searched from 2000 until November 2019, and related clinical studies were included. Lipid metabolism, glycemic status, systemic inflammation, blood pressure, endothelial function, oxidative stress, and anthropometric parameters are the key points regulated by medicinal plants in T2DM. Anti-inflammatory and antioxidant properties are the two most important mechanisms since inflammation and oxidative stress are the first steps triggering a domino of molecular pathological pathways leading to T2DM and, subsequently, CVD. Polyphenols with potent antioxidant and anti-inflammatory effects, essential oil-derived compounds with vasorelaxant properties, and fibers with demonstrated effects on obesity are the main categories of phytochemicals beneficial for CVD of T2DM. Some medicinal plants such as garlic (Allium sativum) and milk thistle (Silybum marianum) have strong evidences regarding their beneficial effects; however, others have low level of evidence which reveals the need for further clinical studies with larger sample sizes and longer follow-up periods to confirm the safety and efficacy of medicinal plants for the management of CVD in T2DM.

Medical Species Used in Russia for the Management of Diabetes and Related Disorders

Background: Polyherbal mixtures called "medical species" are part of traditional and officinal medicine in Russia. This review aimed to analyze medical species used in Russia for the treatment of diabetes and related disorders. The information relevant to medical species, diabetes, and obesity was collected from local libraries, the online service E-library.ru, and Google Scholar. The prediction of the antidiabetic activity for the principal compounds identified in plants was performed using the free web resource PASS Online. Results: We collected and analyzed information about the compositions, specificities of use, and posology of 227 medical species. The medical species represent mixtures of 2-15 plants, while the most frequently mentioned in the literature are species comprising 3-6 plants. The top 10 plants among the 158 mentioned in the literature include Vaccinium myrtillus L., Phaseolus vulgaris L., Taraxacum campylodes G.E. Haglund., Urtica dioica L., Rosa spp., Hypericum spp., Galega officinalis L., Mentha × piperita L., Arctium spp, and Fragaria vesca L. The leading binary combination found in medical species comprises the leaves of V. myrtillus and pericarp of P. vulgaris; leaves of V. myrtillus and leaves of U. dioica; and leaves of V. myrtillus and aerial parts of G. officinalis. In triple combinations, in addition to the above-mentioned components, the roots of T. campylodes are often used. These combinations can be regarded as basic mixtures. Other plants are added to improve the efficacy, treat associated disorders, improve gastrointestinal function, prevent allergic reactions, etc. Meanwhile, an increase in plants in the mixture necessitates advanced techniques for quality control. A feature of medical species in Russia is the addition of fresh juices, birch sap, seaweeds, and adaptogenic plants. Modern studies of the mechanisms of action and predicted activities of the principal compounds from medicinal plants support the rationality of polyherbal mixtures. Nevertheless, the mechanisms are not well studied and reported due to the limited number of compounds. Further investigations with calculations of synergistic or additive indices are important for strengthening the scientific fundamentals for the wider use of medical species in the therapy of diabetes. Two medical species, "Arfazetin" (7 medicinal plants) and "Myrphasinum" (12 medicinal plants), are approved for use in officinal medicine. The efficacy of these species was confirmed in several in vivo experiments and clinical trials. According to modern regulatory rules, additional experiments and clinical trials are required for more detailed investigations of the mechanisms of action and confirmation of efficacy. Conclusion: We believe that the scientifically based utilization of rich plant resources and knowledge of Russian herbal medicine can significantly contribute to the local economy as well as to the sectors seeking natural healing products.

Urtica dioica Extract Inhibits Cell Proliferation and Induces Apoptosis in HepG2 and HTC116 as Gastrointestinal Cancer Cell Lines

BACKGROUND

Nowadays the use of plant-derived products has been extensively examined in the treatment of many types of gastrointestinal cancers such as hepatocarcinoma and colon cancer. Urtica dioica is a traditional herb that has many pharmacological effects and wildly used as a therapeutic agent in cancer. Herein, we have evaluated the effects of the different concentrations of Methanolic Extract of Urtica dioica (MEUD) on viability, death pattern, and expression of the apoptosis-related gene in normal Human Dermal Fibroblast (HDF), hepatocarcinoma cell lines (HepG2) and colon-cancer cell line (HCT116).

METHODS

A high-performance liquid chromatography method was developed to simultaneously separate 3 phenolic acids in MEUD. HepG2 and HCT116 cell lines as well as HDF normal cell line were cultured in suitable media. After 24 and 48h, in the cultured cell with different concentrations of MEUD, cells viability was assessed by MTT assay, and apoptosis was also evaluated at the cellular level by Annexin V/PI flow cytometry analyzing and AO/EB staining. BCL2 and BAX gene expressions were assessed by TaqMan real-time PCR assay.

RESULTS

MEUD showed antiproliferative effects on HepG2 and HTC116 cells after 48h with an IC50 value of about 410 and 420μg/ml, respectively (P < 0.001). Apoptotic cells were observed in HepG2 and HTC116 cells but not in HDF. Furthermore, the increased level of BAX/BCL-2 ratio was observed in HepG2 and HTC116 cells under the treatment of different concentrations of MEUD.

CONCLUSION

The MEUD may influence hepatocarcinoma and colon-cancer cell lines at specific doses and change their proliferation rate by changing the expression of BAX and BCL2.

Trends in diabetes care with special emphasis to medicinal plants: Advancement and treatment

Diabetic mellitus (DM) is a common metabolic disorder prevailing throughout the world. It may affect a child to an older person depending upon the physiology and the factors influencing the internal metabolic system of the body. Several treatments are available in the market ranges from synthetic drugs, insulin therapy, herbal drugs, and transdermal patches. Interestingly, the development of technologies and digital health have proving very helpful in improving the lifestyle of diabetic patients. All treatment approaches have their own advantages and disadvantages in the form of effectiveness and side effects. Medicinal plants have a long history of traditional application in the treatment of diabetes and even the use of plants are growing day-by-day due to the significant results against diseases and fewer side effects as compared to other treatment therapies. The intention behind writing this review is to gather all information and discussed them exhaustively in an article. The novel Coronavirus 2019 (COVID-19) pandemic has affected my lives including diabetic patients. The antidiabetic treatment strategies during this period has also discussed. In this article, we highlighted the molecular mechanism and herbal phytoconstituents that are responsible for lowering blood glucose level. The factors responsible for the progression of metabolic disorders can be controlled with the use of phytoconstituents present in herbal plants to maintain β-cells performance and restore blood glucose level. It can be concluded that medicinal plants are effective and affordable with lesser side effects for treating DM.

The use of South African botanical species for the control of blood sugar

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetes mellitus (DM) is one of the most prevalent diseases globally and is of considerable concern to global health. Approximately 425 million people are estimated to have DM globally and this is predicted to increase to >642 million by 2040. Whilst the prevalence of DM in South Africa is slightly lower than the global average, it is expected to rise rapidly in future years as more South Africans adopt a high calorie "westernised" diet. Traditional medicines offer an alternative for the development of new medicines to treat DM and the usage of South African plants is relatively well documented.

AIM OF THE STUDY

To critically review the literature on the anti-diabetic properties of South African plants and to document plant species used for the treatment of DM. Thereafter, a thorough examination of the related research will highlight where research is lacking in the field.

MATERIALS AND METHODS

A review of published ethnobotanical books, reviews and primary scientific studies was undertaken to identify plants used to treat DM in traditional South African healing systems and to identify gaps in the published research. The study was non-biased, without taxonomic preference and included both native and introduced species. To be included, species must be recorded in the pharmacopeia of at least one South African ethnic group for the treatment of DM.

RESULTS

One hundred and thirty-seven species are recorded as therapies for DM, with leaves and roots most commonly used. The activity of only 43 of these species have been verified by rigorous testing, and relatively few studies have examined the mechanism of action.

CONCLUSION

Despite relatively extensive ethnobotanical records and a diverse flora, the anti-diabetic properties of South African medicinal plants is relatively poorly explored. The efficacy of most plants used traditionally to treat DM are yet to be verified and few mechanistic studies are available. Further research is required in this field.

Urtica dioica L. leaf chemical composition: A never-ending disclosure by means of HR-MS/MS techniques

The metabolite profiling of plant extracts always represents an exciting challenge, as the chemical diversity of natural products is still far beyond the researchers' imagination, even focusing on a plant that is thought to have already been broadly investigated. Herein UHPLC-HRMS/MS techniques were applied to an alcoholic crude extract from nettle leaves and proved to be a precious tool for the disclosure of secondary metabolites never found before. Hydroxycinnamic acid derivatives were the most representative constituents, with a 2-caffeoilisocitric acid cyclodimer described for the first time, besides four C-glycosylated flavones, bearing a 3-hydroxy-3-methylglutaryl function. This deep investigation paves the way for the isolation and full characterization of these molecules by means of spectroscopic techniques. Moreover, based on preliminary cytotoxicity evaluation, further research on the use of this nettle extract as a valuable nutraceutical product is encouraged.

Determination of biological activity of Carduus lanuginosus: an endemic plant in Turkey

The genus Carduus is traditionally used in the Anatolian folk medicine for treating various diseases. Therefore, the enzyme inhibiting potential, antioxidant-antimicrobial activity, and phytochemical profile of Carduus lanuginosus extracts were investigated. The analysis of phenolic compounds was carried out by using RP-HPLC for the chemical characterization of methanol extract. The total polyphenols, total phenolic and flavonoid contents, antioxidant activity (ABTS and DPPH assay), α-amylase, and α-glucosidase inhibition activities were determined using colorimetric methods. Moreover, the antimicrobial activity was examined using the disc diffusion and microdilution methods. The ethylacetate extract was found to have the highest flavonoid and phenolic content. The water and hexane extracts showed strong enzyme inhibitory activity against the α-amylase and α-glucosidase. The methanol extract was found to contain high concentration of chlorogenic acid. The hexane and ethylacetate extracts showed to have significant MIC values on Enterococcus faecium. In conclusion, the extracts of C. lanuginosus might have a significant potential for the use as a natural pharmaceutical agent.

Effects of endurance exercise and Urtica dioica on the functional, histological and molecular aspects of the hippocampus in STZ-Induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Many body systems and organs, including the hippocampus, are affected by diabetes, and undergo changes that may increase the risk of cognitive decline. Urtica dioica (UD) has long been recognized as a medicinal plant with beneficial effects on blood glucose control in diabetes.

AIM OF THE STUDY

The present study aimed to investigate the effect of endurance exercise (Ex), along with Urtica dioica (UD) hydro-alcoholic extract on some functional, histological, and molecular aspects of the hippocampus in streptozotocin (STZ)-induced diabetic rats.

MATERIALS AND METHODS

60 male Wistar rats were divided into five groups (N = 12): healthy control (H-C), diabetes control (D-C), diabetes exercise (D-Ex), diabetes Urtica dioica (D-UD), and diabetes exercise Urtica dioica (D-Ex-UD). Diabetes was induced intraperitoneally by STZ (45 mg/kg) injection. Two weeks after the injection by STZ, Ex (moderate intensity/5day/week) and gavage of UD extract (50mg/kg/day) was performed for six weeks. Cognitive functions were evaluated by the Morris Water Maze test, routine histological examination, and molecular studies were done via Hematoxylin & Eosin stain, and Western blot.

RESULTS

Diabetic rats showed spatial learning and memory deficits, as well as negatively affects to the tissue and structure of the hippocampus in the dentate gyrus (DG) and cornu ammonis (CA) areas. Ex + UD treatment caused a decrease of neural disorganization, an increase of neural-microglial density, and thickness of the pyramidal-molecular layer in the hippocampus. In addition, Ex + UD caused a rise of GAP-43 protein levels, a reduction of CAP-1 protein levels, improved hippocampal structure, and improved learning and memory function.

CONCLUSIONS

These results show that Ex, along with the UD extract, may decrease levels of the central neural complications of diabetes. Given the importance of recognizing non-pharmacological complementary therapies in this field, future studies are warranted.

The effect of nettle (Urtica dioica) supplementation on the glycemic control of patients with type 2 diabetes mellitus: A systematic review and meta-analysis

Type 2 diabetes mellitus (T2DM) is a major health problem, worldwide, that is associated with increased morbidity and mortality. Several randomized controlled clinical trials (RCTs) have investigated the effect of nettle (Urtica dioica) supplementation on markers of glycemic status in patients with T2DM, with conflicting results. Therefore, the present study assessed the effect of nettle on some glycemic parameters in patients with T2DM. A comprehensive search was conducted in PubMed, Scopus, Cochrane Library, and Web of Science, from database inception up to June 2019, to identify RCTs investigating the effect of nettle supplementation on glycemic markers, including fasting blood sugar (FBS) concentrations, insulin levels, homeostasis model assessment-estimated insulin resistance index, and glycosylated hemoglobin percentage in adults with T2DM. The Cochrane Collaboration tool was used to assess the methodological quality of the included studies. Results of this meta-analysis were reported based on the random effects model. Eight RCTs, comprising 401 participants, were included in the present systematic review and meta-analysis. Based on the Cochrane Collaboration risk of bias tool, five studies were considered as good quality, one was fair, and two studies were poor, respectively. The results of the meta-analysis revealed a significant reduction in FBS concentrations (weighted mean difference [WMD]: -18.01 mg/dl, 95% confidence interval [CI]: -30.04 to -5.97, p < .001, I² = 94.6%) following nettle supplementation. However, no significant reduction was observed in insulin levels (WMD: 0.83 Hedges' g, 95% CI: -0.26 to 1.92, p = .13, I² = 89.4%), homeostasis model assessment-estimated insulin resistance index (WMD: -0.22, 95% CI: -0.83 to 0.40, p = .49, I² = 69.2%), or glycosylated hemoglobin percentage (WMD: -0.77%, 95% CI: -1.77 to 0.22, p = .12, I² = 83.0%). The findings of the present study suggest that nettle supplementation may be effective in controlling FBS for T2DM patients. However, further studies are needed to confirm the veracity of these results.

Therapeutic Perspectives of Molecules from Urtica dioica Extracts for Cancer Treatment

A large range of chronic and degenerative diseases can be prevented through the use of food products and food bioactives. This study reports the health benefits and biological activities of the Urtica dioica (U. dioica) edible plant, with particular focus on its cancer chemopreventive potential. Numerous studies have attempted to investigate the most efficient anti-cancer therapy with few side effects and high toxicity on cancer cells to overcome the chemoresistance of cancer cells and the adverse effects of current therapies. In this regard, natural products from edible plants have been assessed as sources of anti-cancer agents. In this article, we review current knowledge from studies that have examined the cytotoxic, anti-tumor and anti-metastatic effects of U. dioica plant on several human cancers. Special attention has been dedicated to the treatment of breast cancer, the most prevalent cancer among women and one of the main causes of death worldwide. The anti-proliferative and apoptotic effects of U. dioica have been demonstrated on different human cancers, investigating the properties of U. dioica at cellular and molecular levels. The potent cytotoxicity and anti-cancer activity of the U. dioica extracts are due to its bioactive natural products content, including polyphenols which reportedly possess anti-oxidant, anti-mutagenic and anti-proliferative properties. The efficacy of this edible plant to prevent or mitigate human cancers has been demonstrated in laboratory conditions as well as in experimental animal models, paving the way to the development of nutraceuticals for new anti-cancer therapies.

Use of alternative medicine, ginger and licorice among Danish pregnant women - a prospective cohort study

BACKGROUND

The use of alternative medicines and dietary supplements is constantly changing, as are dietary habits. One example of this phenomenon is the current popularity of ginger products as an everyday health boost. Ginger and licorice has also been shown to ameliorate nausea a common complaint in early pregnancy. Alternative medicines are often regarded as safe. However, they might affect fetal development, such as through alterations of hormone metabolism and cytochrome P450 function. Health care professionals may be unaware of the supplementation habits of pregnant women, which may allow adverse exposures to go unnoticed, especially if the rates of use in pregnancy are not known. We therefore investigated the use of alternative medicines and licorice among pregnant Danish women.

METHODS

A total of 225 pregnant women were included in a prospective cohort when attending the national prenatal screening program at gestational weeks 10-16. Participants were asked to complete a questionnaire regarding their socio-economic status and lifestyle habits, including their intake of alternative medicine and licorice.

RESULTS

We found that 22.7% of women reported taking alternative medicines, with 14.7% reporting daily consumption. Ginger supplements were consumed by 11.1%, mainly as health boost and 87.1% reported consumption of licorice. Regular or daily licorice consumption was reported by 38.2 and 7.1%, respectively. Notably, the use of licorice was reflected by an increase in blood pressure of the pregnant women.

CONCLUSIONS

The use of licorice and alternative medicines appears to be common in pregnant Danish women, supporting the need for further investigations into the safety of alternative medicine use during pregnancy and the importance of up-to-date personalized counseling regarding popular health trends and lifestyle habits.