Plants Used in Podkarpackie Voivodeship (Poland) To Treat Urinary Diseases

This manuscript contains the results of Podkarpackie Voivodeship (Poland) ethnomedical studies on the treatment of urinary tract diseases using wild and cultivated plants. The study concerns plants mainly used for the supportive treatment of urinary tract infections, urolithiasis and benign prostatic hyperplasia. In this present study, we aim to collect and assess the ethnomedicinal potential of plants used in Podkarpackie Voivodeship (Poland) to treat urological diseases. This article is based on interviews with fourteen recognized traditional healers (urban areas) and nine informants (rural areas) living in the south-eastern region of Poland - Podkarpackie Voivodeship. The survey took place between November 2019 and January 2021. For each plant mentioned in herbal remedies, polish name, part used, mode of preparation, and their properties, according to the healers and informants, were recorded.


Results
For the analysis, 123 species that belong to 43 families were selected. The most common families used to treat urinary diseases in Podkarpackie herbal medicine are the Compositae (18 species), Rosaceae and Apiaceae (11 species in each), Leguminosae (9 species), and Ericaceae (6 species). Of the species listed, Apium graveolens L., Arctium lappa L., Arctostaphylos uva-ursi (L.) Spreng., Elymus repens (L.) Gould, Juniperus communis L., Matricaria chamomilla L., Petroselinum crispum (Mill.) Fuss, Solidago virgaurea L., Urtica dioica L., and Viola tricolor L. were the most frequently mentioned. Most plants are used in multicomponent blends, which are given in the form of infusions or decoction. The described plants have mainly antiseptic, diuretic, spasmolytic and anti-in ammatory properties.

Conclusions
The results of the research described in this paper indicate that herbal treatment of urinary tract diseases is still used in Poland in the Podkarpackie Voivodeship. It is mainly used by people who do not want to use allopathic medicine, especially antibiotics. They are both inhabitants of large cities and villages. The latter often because of the multi-generational tradition, prefer self-healing.

Background
The urological diseases are most commonly associated with the ltration and carrying out of urine from the body. These diseases can occur in people regardless of gender. In males health problem concerns the urinary tract and/or the reproductive organs, while in females this problem usually affects only the urinary tract. The most numerous are bacterial infections of the lower urinary tract, especially recurrent (asymptomatic bacteriuria, urethritis, cystitis, prostatitis), urolithiasis, benign prostatic hyperplasia (1).
Urinary tract infections (UTI) occur in the entire population, but they are particularly sensitive to young children, pregnant women and postmenopausal women, as well as men with prostatic hyperplasia. The prevalence of UTI increases with age. The vast majority of infections (over 90%) are infections that start with the urethra and, if not treated, continue to spread via single urinary tract to the kidney or bilaterally (2).
Urolithiasis is one of the most commonly diagnosed disease of urinary tract and the frequency of its occurrence is about 9% of the general population (3,4). Urolithiasis occurs both in men and women, and is diagnosed in about 10% of men and 6% of women (5). Urinary stones are most common in women and men between the ages of 20 and 60 and the occurrence peak of the disease is 50 years old. Over a period of ve years the risk of disease recurrence and the chance of second stone formation is a 30% to 50% (6).
Benign prostatic hyperplasia (BPH) is an age-related disease of the prostate present in 70% of men at the age of 60 years. BPH is characterized by histopathological hyperplastic changes of smooth muscle cells and epithelial cells within the prostatic transition and periurethral zons (7,8).
Herbal medicines have a long history of use around the world. It is assumed that they are safer than synthetic drugs and may support some drug therapies. Natural products usually can be used continuously without signi cant metabolic and clinical consequences (9,10). One of the divisions assumes that there are three main categories of plants used in the treatment of urological diseasesbotanical diuretics, urinary antiseptic and anti-adhesion, and herbs used to treat benign prostatic hyperplasia (11). Numerous plants are traditionally considered diuretic, what the preliminary clinical trials con rm, both in healthy and people with urologic disease. Although the precise mechanism of this action, in many cases, remains unclear (12). The classic herbal diuretic drugs are not diuretics at all but aquaretics. These usually contain volatile oils, avonoids, saponins, or tannins, which increase the volume of urine by promoting blood ow in the kidneys, thereby raising the glomerular ltration rate. However, they do not retard the resorption of Na + and Clin the renal tubules, so quantities of these electrolytes are retained in the body and not excreted with the water (13). An increased urine ow can nd another application in the prevention of kidney stones. There are many causes for the formation of kidney stones, but the major determinant is an increased urinary concentration of the constituents making up the stones (14). Diuretic herbs can prove useful for minor infections, which bene t from an increased volume of urine, e.g. pyelonephritis (local infection of the renal tissues), urethritis or ureteritis (in ammation of the urethra or of a ureter) and cystitis (in ammation of the urinary bladder). Some of the herbs also exhibit antibacterial properties that, in combination with the increased urinary output, are useful in combating infection. There are two major mechanisms of this process -targeted killing of microbes and interference in their adhesion to epithelial cells (12).
It is commonly believed that traditional, rural folk medicine is more characteristic of underdeveloped communities located usually in the eastern part of Europe (Poland, Lithuania, Belarus, and Ukraine). Traditional folk medicine and self-treatment are strongly associated with Polish culture and tradition. Folk treatment methods have not only not disappeared in the rural areas but ethnological, sociological and medical studies suggest that they seem to be enjoying social acceptance (15)(16)(17)(18)(19)(20).
Between the 1940s and 1980s, folk medicine was identi ed with ignorance. Folk methods of treatment were vigorously fought against while folk healers were forced to abandon their practice. It appeared that in accordance with the plans and prospects of the "socialist health service" these methods of treatment were destroyed, disintegrated and forgotten. It turns out, however, that many practices of folk "medicine" continue to be used in local communities (19).
The present paper collects information about the plants used to treat urological diseases in Polish traditional medicine applied in the region of the Podkarpackie Voivodeship. This data was obtained through interviews with traditional healers and local informants. The purpose of this survey was to document the treatment practices of traditional healers in relation to urinary tract diseases, with the use of medicinal plants.

Study area
The study was conducted in Podkarpackie Voivodeship, a province in south-eastern Poland (Fig.1). This region is also known as Subcarpathian Voivodeship or Subcarpathia Province. It covers an area of over 17,000 square kilometers and its administrative capital is Rzeszów. It borders with the following provinces: Małopolskie (in the west), Świętokrzyskie (in the north-west), Lublin (in the north), Ukraine (in the east) and Slovakia (in the south). Forests cover about 35% of the region's area, including the Bieszczady National Park and parts of the Magura National Park (21).

Data collection
A survey was carried out from November 2019 to January 2021. This article is based on interviews with 14 recognized traditional healers living and healing in cities (Jasło, Krosno, Łańcut, Rzeszów, Sanok, Tarnobrzeg) and 9 informants living in rural areas (Blizne, Domaradz, Golcowa and Lutcza) in the Podkarpackie Voivodeship. Among the traditional healers two of them were herbalists in markets. In Fig.  1 (in brackets) the number of healers/informants coming from a given place was given. The informants were mostly local older people interested in herbalism, family members and friends. They only provided information on the symptoms reported by the sick, the plants used and how they were prepared. In the case of traditional healers data were collected based on the completed questionnaire sent via e-mail. The questions concerned sociodemographic data, diagnosis methods, types of urinary tract diseases most commonly found in patients and recommended medications. This article is based on knowledge obtained from recognized traditional healers and informants who were born or have lived most of their lives in the studied region.Participants were given the option to choose whether they want to share their knowledge.

Results And Discussion
Socio-demographic data and the characteristics of healers professional practice The questionnaire was completed by 14 healers (about 30% of all invited), whose age was between 43 and 71 years. They were all men and had higher level medical education -medical doctor (6) and physiotherapist (8). Eleven of them additionally completed herbal medicine courses. Three healers did not provide details of education in relation to phytotherapy. Apart from the two owners of herbal shops, the others met with patients in a consultation room usually twice a week.

Diagnostic methods
All practicing healers (12) had an early interview with patients and next made a decision about treatment based on medical report (urine test and/or imaging of the urinary or genitourinary system). Herbalists from markets (2) did not give patients a nal diagnosis and did not use medical records. The herbs they recommended could not be used for more than 7 days. In the absence of improvement after this time, patients were to consult a primary care physician. The most frequently occurring symptoms and diseases were: pain during urination and frequent urination (infection of bladder or urethra, stone in bladder, prostatitis or enlarged prostate); blood in the urine (infection, stone, tumour); pain in the loin and/or groin (stone, infection, kidney tumour); sediments in urine (infection and/or stone). All respondents mentioned these symptoms.

Herbal remedies
In total, 123 species belonging to 43 plant families used in Podkarpackie Voivodeship by healers and reported by informants for the treatment of urinary diseases were examined. Table 1 presents the plant nomenclature, the main Polish name, English common name, part used, utilization and administration, and number of citations. All the healers and informants reported that about 1 tablespoon of dried herb for a glass of water is used to prepare the infusion or decoction. In the case of fresh raw materials, the quantity was about half lower. Most often, dried material was used. If the plant was used only in mixtures, it was written in brackets -(used in blends).
Plants are listed alphabetically by plant family, and then by species within them. The greatest numbers of plant species used to treat urinary diseases were found to come from the Compositae (18 species), Rosaceae (11 species), Apiaceae (11 species), Leguminosae (9 species) and Ericaceae (6 species). A literature search of reported species reveals that the majority lack the necessary supporting data to prepare a scienti c explanation for their traditional uses in treating urinary diseases. The study therefore evaluates the available scienti c evidence for all reported species, to identify any possible scienti c bases for their use.

Medical treatment strategies declared by healers
All traditional healers (14) have declared that suspected malignant tumour, urinary tract obstruction and severe cardiovascular disorders disquali ed patients from herbal treatment. Table 2   In addition to phenolic glycosides, phenolic acids, found in Arctostaphylos uva-ursi (L.) Spreng. and Vaccinium vitis-idaea L. in free form and as tannin hydrolysis products, have also antimicrobial activity.
Herbalists making their own mixtures tried to make them also anti-in ammatory, diuretic and antispasmodic, hence the frequent addition of Matricaria chamomilla L., Taraxacum campylodes G.E.Haglund., Urtica dioica L. and Urtica urens L.. 9/14 healers declare that they recommend the use of Vaccinium microcarpum (Turcz. Ex Rupr.) Schmalh. to reduce bacterial colonization. They recommend drinking juice and fruit infusions/decoctions with the indication that they are a dietary agents for long-term use.
In relation to benign prostatic hyperplasia, the treatment of all healers was identical. They recommended antibacterial therapy and the use of commercial preparations. The three most commonly used are Prosterol or Prosterol x (pills, blend), Poldanen (pills) and Peposterol (pills) and possibly a blend of Father Klimuszko, Polish religious and herbalist.
Infusions and decoctions were made from one tablespoon of herbs per glass of water and applied three times a day, on average for two weeks. All healers state that their herbal therapies for some urinary tract diseases are highly effective. They emphasized that the basis of success are accurate diagnosis and medical documentation of the disease, e.g. blood and urine analysis, imaging tests.

Medical treatment strategies declared by informants
In general, rural herbalists treated urinary tract diseases based on symptoms, without medical records. Benign prostatic hyperplasia was not isolated as a separate disease. Urinary tract tumors were also not recognized. Mainly infections and symptoms of urolithiasis were treated. Many of the herbs currently used by professional healers have been used in rural medicine. This is evidenced by the number of citations given in Table 1 in the last column. Values of about 20 testify that the medicinal properties of the plant were known to both rural herbalists and modern healers practicing in cities. These plants are well tested for composition and pharmacological activity and are described in the literature. However, there is a group of herbs whose use is mentioned only in rural medicine and there is no scienti c basis for the use of these plants.
The information obtained shows that rural herbalists mainly use individual plants in medicine, which gives little effect in the case of urinary tract diseases. People who undergo ineffective treatment then choose commercial herbal preparations themselves after consulting a pharmacist.
Plants used in Podkarpackie Voivodeship whose therapeutic effect on urinary tract has been con rmed by scienti c ndings (in alphabetical order) Achillea millefolium L.
The Compositae is one of the most widely known families, including a large number of owering plants classi ed into about 23,000 species.One such species is Achillea, whose members have various pharmaceutical properties. They have been recommended as useful tonic, sedative and diuretic (24). In addition, it is common to see the consumption of herbal teas from different species of Achillea in folk medicine. In vitro and in vivo clinical tests have con rmed the possibility of various therapeutic applications. Various authors note that Achillea millefolium has important traditional and ethnomedicinal properties when drunk as tea, including treating urinary disorders; it has been used in various countries, particularly in Europe (24)(25)(26). The varied effects of these plants may be due to to the presence of numerous secondary metabolites, i.e. phenolic acids, avonoids, terpenoids and sterols. De Souza et al. (27) demonstrated that A. millefolium extract, when is orally administrated in rats, are able to effectively increase diuresis. This effect depends on the activation of bradykinin B2 receptors and the activity of cyclooxygenase.
For centuries, Acorus calamus has been used in Polish folk medicine for the treatment of urinary diseases (15). It is also used in modern medicine. Ghelani et al. (28) in studies conducted on male albino Wistar rats showed the diuretic and antiurolithiatic effect of the ethanolic extract from A. calamus. The use of this extract caused increased diuresis and limited excretion of calcium, oxalate, phosphate and uric acid.
Aegopodium podagraria is a perennial herb of the carrot family (Apiaceae). It is indigenous to Europe, western and eastern Siberia, the Caucasus, and Central Asia mountainous regions and has been naturalized in North America. Koyro et al. (29) demonstrated that the essential oil of the owers has the diuretic and uricosuric activity. Another study examined the in uence of the extract and tincture of the aerial parts of A. podagraria in rats receiving excess fructose combined with hydrochlorothiazide (30).
The authors observed that plant tested extract signi cantly enhances kaliuresis.
Amaranthusretro exus is an upright annual herb which was probably introduced into Europe from North America. Currently it is common throughout Poland (31). The plant is known to have a number of toxic principles; for example, Osweiler et al. (32) demonstrated that A. retro exus induced production of perirenal edema in pigs. Microscopical lesions include renal tubular degeneration and necrosis. Kessell et al. (33) observed acute renal failure to be associated with Amaranthus species, including A. retro exus ingestion by lambs.
In traditional medicine, some medicinal plants, i.e. corn silk, barley and celery were used to relieve some renal paints. Apium graveolens is a popular vegetable added to many dishes such as salads, which has been used in Chinese medicine to reduce blood pressure and in Arabian medicine to relieve renal points (12,(34)(35)(36) observed that celery accentuates urinary Ca 2+ excretions in experimental model of nephrocalcinosis, and produced a signi cant reduction of blood urea nitrogen and serum creatinine.
Renal functions were analyzed in 1 st , 5 th and 10 th day.
In Europe and America, Arctostaphylos uva-ursi is particularly often used to treat lower urinary tract infections.The key constituents of the dried leaves are the phenolic glycoside arbutin and its derivate hydroquinone, both of which antiseptic activity in in ammation of the urinary tract (37). Although arbutin is the major pharmacological active constituent of the A. uva-ursi leaves extract, experimental studies indicate that their global pharmacological action requires the use of the whole extract. Haslam (38) described that the dried leaves of Arctostaphylos uva-ursi have a soothing astringent effect, and that they can be used as a diuretic in kidney disorders and aliments of the bladder and urinary tract. The principal phenolic metabolites in the leaf are arbutin, gallotannins, and galloyl esters of arbutin.
Of the hundred Betula species identi ed in the world, only 7 of them were used in traditional medicine. Especially the use of B. pendula has been documented. The results of tests published by Rastogi et al. (39) show the biological properties of this plant. Extracts of B. pendula leaves are traditionally used against rheumatic pin and arthritic diseases. In addition, different experiments suggest that these extracts possess mild diuretic action and anti-in ammatory properties. B. pendula extract reduces the growth and proliferation of activated T lymphocytes in a dose-dependent manner, and this has been attributed to the action of secondary metabolites (i.e. phenolic acids and avonoids) within the leaves (40,41). Also, an ethanol-water (1:1; v/v) extract from the Betula spp. leaves has been found to have an antiadhesive effect against the binding of uropathogenic Escherichia coli to the bladder cell surface (cell line T24). Decreased bacterial adhesion (IC 50 415 mg/mL ± 7.19) was observed, and this action is linked with the prevention of urinary tract infections (42).

Bidens tripartita L.
Another member of the Composite is Bidens tripartita. It is used in oriental medicine to increase sweat secretion and as a diuretic (43,44).

Carum carvi L.
In folk medicine dried fruit of Carum carvi is often used because of its carminative and therapeutic properties for gastrointestinal complaints (45). In traditional Moroccan medicine, C. carvi fruits are used as diuretics, however, their effect has not been con rmed in controlled studies. On the other hand, Lahlou et al. (46) report that the aqueous extract of C. carvi demonstrated diuretic properties in normal rats.
In traditional medicine, Daucus carota has been used mainly to treat nephrosis and other urinary disorders. Sodimbaku et al. (47) have observed that the carrot has dose-dependent nephroprotective activity against gentamicin-induced nephrotoxicity in rats. This protection was manifested by lowering the levels of serum urea, blood urea nitrogen, uric acid and creatinine. Also, concurrent treatment with D. carota extract signi cantly inhibited gentamicin-induced weight loss.
Elsholtzia ciliata is widely distributed throughout China, Korea, and Europe. In Poland it mainly occurs in eastern areas (48). An in vivo study found that ethanol extract of this plant inhibits renal interstitial brosis induced by unilateral ureteral obstruction. This effect may be mediated by inhibiting the expression of KIM1 (kidney injury molecule 1), TNF-(tumor necrosis factor ), TGF-ß (transforming growth factor ß) Smad3 and MMP 9 (matrix metalloproteinase 9) protein, which are markers of in ammation and renal histopathological alterations. An in vitro study based on MTT (3-(4,5methylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay showed E. ciliata ethanolic extract to have no cytotoxic effect, even at a concentration of 200 µg/ml. The study was conducted for 24 hours on the mouse macrophage cells RAW 264.7 cells and human renal mesangial cells (49).

Elymus repens (L.) Gould
Elymus repens is native from temperate Europe to Central Asia and is now found in Africa. Its traditional use is associated with diuretic properties and relief of pain and spasm of the urinary tract. It is often used to treat enuresis and urinary incontinence, for the control of symptoms of the urinary disease, urinary calculi and urinary infections (cystitis, urethritis, prostatitis) (50). In clinical study, the effects of the combined treatment of A. repens with potassium citrate were assessed in patients with nephrolithiasis. After ve months the treated group showed a signi cant reduction in the total number (−1.0 ± 0.2 vs. 0.0 ± 0.2 stones) and diameter of the stones (−3.6 ± 0.9 mm vs. 0.0 ± 0.8 mm), as well as a reduction in the urinary excretion of uric acid (51). It was also shown that under in vitro conditions, E. repens has antiadhesive effects against the binding of uropathogenic Escherichia coli on the surface of the bladder cell (cell line T24). Decreased bacterial adhesion (IC 25 630 mg/mL) was observed, and this effect has been linked with the prevention of urinary tract infections (42). In a clinical trial in patients with micturition disorders, an ethanolic extract of Elymus repens caused a reduction of urinary incontinence, dysuria, nycturia and tenesmus due to adenoma of prostate, prostatitis and cystitis (52).
The genus Equisetum consists of 30 species of rush like, long-standing herbs. Equisetum arvense extract is used as a pain relieving agent and a mild diuretic. It is very effective in removing water from the body.This activity is due to the action of different components, i.e. potassium, equisetonin, calcium, magnesium, caffeic acid and ascorbic acid (53)(54)(55). Recently, Carneiro et al. (56) observed that a standardized dried extract of E. arvense had a diuretic effect that was stronger than hydrochlorothiazide in healthy male volunteers. There was no effect of E. arvense on the excretion of electrolytes in urine and it was approved as safe for oral use.

Foeniculumvulgare Mill.
Foeniculum vulgare is a biennial medicinal and aromatic plant, and its bulbs and fronds have a culinary application (57). El Bardai et al., (58) showed that administration of F. vulgare fruit extract signi cantly increased, both, urinary volume, potassium and sodium excretion. The dose was chosen according to these used in Moroccan traditional medicine.

Fraxinus excelsior L.
In world folk medicine, Fraxinus species have been used for their diuretic and therapeutic effects on bladder in ammation. In Polish folk medicine, the bark and leaves of Fraxinus excelsior, native to Europe, are used to treat various conditions, including wound healing, diarrhea and dysentery (59). Aqueous and ethanol extracts from F. excelsior leaves facilitated renal excretion, increased sodium and chloride, potassium and urea excretion. It is believed that avonoids are mainly responsible for this activity (60). Also, daily oral administration of Fraxinus excelsior aqueous extract in hypertensive rats, produced a signi cant urination, increase urinary excretion of sodium, potassium and chlorides (61).

Humulus lupulus L.
Humulus lupulus is widely used in the brewing industry. Chalkones, bitter acids and terpenes have been identi ed in hop cones (62). In traditional medicine, hops are used to treat sleep disorders. In addition, some in vitro and in vivo experiments support the value of hops as traditional antibacterial and antifungal remedies, and others show them to have diuretic activity.

Juniperus communis L.
In folk and o cial medicine, juniper berries (Juniperus communis) are believed to have diuretic, antiseptic, stomachic and carminative activities. Juniper berries contain 0.5-2% of essential oil, which is source of phenolic compounds, carbohydrates, fatty acids and sterols. It was found that the diuretic activity of juniper berries is the result of the action of essential oil and hydrophilic constituents (63).

Lycopodium clavatum L.
Lycopodium clavatum is a pteridophyte growing in the tropics, subtropically, as well as in European forests.This plant is used to relieve gastric in ammations, simpli es digestion and for the treatment of chronic kidney disorders (64). It has been shown that L. clavatum can play a role in alternative treatment of gout by inhibiting xanthine oxidase. Alcoholic and aqueous extracts (50-100μg/mL) of the whole plant inhibit oxidase activity in 13-58% (65).

Nigella sativa L.
Nigella sativa seeds are traditionally used for culinary purposes in the Indian subcontinent, in Arab countries and Europe. They are also used in the folk treatment of asthma, hypertension, diabetes and various in ammations.The seeds and its oil are used as a carminative and in food as a spice (66), but are rarely cultivated as a spice in Poland (atlas-roslin.pl). Zaoui et al., (67) found that the dichloromethane extract of N. sativa seeds possesses a strong diuretic action in spontaneously hypertensive rats. The diuretic effect of the extract was about 16% greater than that of frusemide, which increased diuresis by 30%. Diuresis was accompanied by an increase in the excretion of chloride, sodium, potassium and urea.

Petroselinum crispum (Mill.) Fuss
Petroselinum crispum, commonly known as parsley, is used as carminative, gastro tonic, diuretic and an antiseptic of the urinary tract. In addition, in Bulgarian phytotherapy, various parts of P. hortense (leaves, seeds and roots) are thought to have diuretic activity (68).
Ribeiro et al., (69) investigated the action of aqueous-ethanol extract from the seeds of P. sativum which was administered to rats. Increased urinary urinary volume and sodium excretion was observed, and these effects were similar to that of furosemide. Yarnell (12) notes that P. crispum has strong potency, which was comparative properties of other herbal diuretics, including Taraxacum o cinale and Ononis compestris, whose potential is regarded as medium. The key active compounds of P. sativum are various phenolics, including avonoids such as apigenin and appinin, and these compounds have a range of biological properties, including diuretic activities (68). In addition, Kreydiyyeh and Usta (70) suggest that aqueous parsley seed extract has a diuretic effect, and the mechanism of action of parsley seems to be mediated by through an inhibition of the Na + -K + pump that would lead to a reduction in Na + and K + reabsorption leading thus to an osmotic water ow into the lumen, and diuresis. In other experiments, Alyami and Rabah (71) report no signi cant difference in urine volume, nor the pH, sodium, chloride, potassium, magnesium, urea, creatinine, uric acid or citric acid composition of urine, nor any inhibition of urinary tract stone formation following the consumption of parsley leaf tea. Saeidi et al. (72) have also observed that aqueous extracts of P. sativum have a therapeutic effect on calcium oxalate stones in rats and that it reduces the number of calcium oxalate deposits. It has been observed that P. sativum extract signi cantly increases the calcium level and decreases the magnesium level in serum.
Plantago major L.
Plantago major a perennial herb, is found wild throughout the whole Europe and temperate Asia. Folk medicine uses all parts of this plant in the preparation of medications helpful in the treatment, among others, cough, diarrhea, or treatment of urolithiasis (73). The ethanol extract of P. major signi cantly inhibited the growth of calcium oxalate crystals (dihydrate variety) in vitro. It has been shown that P. major extract was better than allopurinol and potassium citrate in the reduction of the risk of renal outcomes (74).

Rosa canina L.
Rosa canina a plant native to the Poland is also found in other European countries (75). Its fruit is extensively used worldwide in foods such as jelly and jam, in various beverages such as tea, and in traditional medicine to treat urate metabolism disorders. The nal product in the purine metabolism are urates, in the metabolism of which is involved xanthine oxidase (XO). These processes occur in the liver. An imbalance of serum urate production and excretion induces hyperuricemia, which also develops into gout and kidney stones, and accelerates the progression of renal diseases. In vitro studies have shown that R. canina extracts inhibited XO activity and signi cantly reduced the levels of serum urate eight hours after administration. It is suggested that this hot water extract may serve as a functional food for individuals with a high urate level, and as a therapeutic reagent for hyperuricemic patients (76). The aqueous extract of Rosa canina reduced the content of calcium in the kidneys and urine, and also reduced the size of CaOx stones in the kidneys. It also increased the excretion of citrate without affecting urine volume and pH (77).
Sambucus ebulus is a herbaceous plant well-known in traditional European Medicine for its healing effects in many disorders; however, its toxicity limits its value as a food (78). Dimkov (79) indicates that decoction of S. ebulus has diuretic and diaphoretic properties. Also, Beaux et al., (80) report increased excretion of sodium in rats after administration of S. nigra ower extract. According to Walz and Chrubasik (81), S. nigra concentrate can be safely administered to patients with idiopathic nephrolithiasis. This concentrate did not affect urine pH or hydrogen ion concentration.

Taraxacum campylodes G.E.Haglund
Taraxacum campylodes is a widespread perennial of the Asteraceae. It is commonly considered as weed, but has a wide range of chemical components which confer healing properties. Most of the active substances found in T. campylodes are phenols and terpenes; however, carbohydrates, proteins, fatty acids, vitamins and minerals are also present. This range of compounds has resulted in the plant being used for centuries as a natural drug in the treatment of gout and diarrhea, as well as problems associated with the bladder, spleen and liver (82). Leaf ethanol extract (1 g/ml) demonstrates a diuretic effect in a group of women treated with the extract every ve hours for four days, with no side effects observed (83)(84)(85).
Urtica dioica is a temperate and tropical plant. It is common throughout Poland (31). Traditionally, the leaves and roots of plant have a very wide range of ethnomedicinal applications, although in different capacities. Urtica urens also demonstrates similar pharmacological properties (86). The extract of U. dioica increase diuresis by 11% when administered at a low dose (4 mg/kg/h) and by 84% at a high dose (24 mg/kg/h); it also induces natriuresis by 28% and 143% at the same respective low and high doses (87). Studies on the effects of U.dioica preparations on humans have been limited (86,88). In vitro studies have found that, like Betula spp. and Elymus repens, Urtica spp. shows an antiadhesive effect against the binding of uropathogenic Escherichia coli on the surface of bladder cells (IC 25 630 mg/mL) (42). Urtica dioica ethanol extract at a dose of 1g/kg (po) does not affect diuretic activity, while a dose of 500 mg/kg (ip) causes a signi cant increase in this activity (86).

Vaccinium myrtillus L.
Vaccinium myrtillus is a small deciduous shrub, which is very popular in Poland and other European countries. The leaves are used in folk medicine as decoctions and infusions for treating conditions associated with the urinary tract thanks to their astringent and antiseptic properties (89). Vaccinium vitis ideae is another evergreen small shrub growing in Europe; its berries are known to have the same properties as V. myrtillus fruits, while the leaves have diuretic and urinary antiseptic activities, which have been attributed to their high concentration of tannins, arbutin and arbutin derivatives (89).

Viola tricolor L.
Viola tricolor has a long history in phytomedicine. It aerial parts have been described and used for centuries in Europe for the therapy of skin disorders, upper-respiratory problems, and also used as a diuretic (90). The Polish ora records that V. tricolor in habits areas throughout the country at lowland and lower mountain locations (91). Saponins Arbutin is particularly important in the treatment of infection. This compound are a phenolic glycoside and is present, among others, in Arctostaphylos uva-ursi (L.) Spreng. and Vaccinium vitis-idaea L.. This compound is primarily hydrolyzed in the intestines to hydroquinone, and then absorbed, metabolized, and excreted via the urine. Part of the antimicrobial activity of quinones has been attributed to the ability of these compounds to irreversibly complex with nucleophilic amino acids in proteins. They affect the cell surface-exposed adhesins, cell wall polypeptides, and membrane-associated enzymes. In turn, avonoids are synthesized by plants as a defense against microbial infection. Both avonoids and tannins are believed to act in a manner similar to quinones in inactivating microbial adhesions, enzymes, and cell envelope transport proteins, as well as possible direct inactivation of microorganisms. Tannins have been reported to elicit antimicrobial activity against lamentous fungi, yeasts, and bacteria (96,97).
The triterpene saponins may stimulate microcirculation due to their surfactant properties. The diuretic action of these compounds is believed to be associated with local irritation of kidney epithelia. The diuresis caused by plants such as Ononis spp., Betula spp. and Solidago species is relatively mild, and the effect may originate from the accompanying avonoids and essential oils. An alternative theory is that the potassium content of these plants is in fact the diuretic agent (98). Some essential fatty acids may exhibit both anti-in ammatory and pro-in ammatory properties, modulating the immune response (94).
The In turn, single herbs used in rural medicine are de nitely ineffective or work too weakly. Attention should also be paid to the use of plants, which are mentioned by rural herbalists, but there is no scienti c basis for their use. These plants de nitely require con rmation of their medicinal properties and lack of toxicity. This requires careful research.

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The authors declare that they have no competing interests.  If the plant is used only in mixtures, it is written in brackets -(used in blends).