Violae herba cum flore – Wild Pansy (Violae tricoloris herba cum flore)
|Latin name of the genus:||Violae herba cum flore|
|Latin name of herbal substance:||Violae tricoloris herba cum flore|
|Botanical name of plant:||Viola tricolor l. and/or subspecies viola arvensis murray (gaud); viola vulgaris koch (oborny)|
|English common name of herbal substance:||Wild pansy|
Latin name of the genus: Violae herba cum flore
Latin name of herbal substance: Violae tricoloris herba cum flore
Botanical name of plant: Viola tricolor L. and/or subspecies Viola arvensis Murray (Gaud); Viola vulgaris Koch (Oborny)
English common name of herbal substance: Wild Pansy
The herbal substance of wild pansy and/or European field pansy is mentioned in several well known handbooks such as Madaus (1938), Martindale (2007), Wichtl (1994; 2004), PDR for Herbal Medicines (2000; 2004), German Commission E Monograph, European Pharmacopoeia 6.0, Duke’s Handbook of Medicinal Herbs (2002), Hänsel et al. (1994) and Chevallier Encyclopedia of Medicinal Plants (1996).
In the European Pharmacopoeia it is described as the dried flowering aerial parts of Viola tricolor L. (wild pansy) and/or spp. Viola arvensis Murray (Gaud.) and Koch (Oborny) (European field pansy). Wild pansy must contain at least 1.5 percent of flavonoids, calculated with reference to the dried substance, expressed as violanthin.
Wild pansy belongs to the family of Violaceae. The herb is distributed in Europe and Asia. Flowering aerial parts of wild pansy are harvested during summer.
1.1. Description of the herbal substance(s), herbal preparation(s) or combinations thereof
Herbal substance(s) Not applicable.
Herbal preparation(s) Oral use:
3 g of the comminuted herbal substance/250 ml of water. Dry extract: dry extract (6:1), extraction solvent: water.
5 – 20 g of the comminuted herbal substance/litre of water
Combinations of herbal substance(s) and/or herbal preparation(s) including a description of vitamin(s) and/or mineral(s) as ingredients of traditional combination herbal medicinal products assessed, where applicable.
1.2. Information about products on the market in the Member States
According to the information provided by the National Competent Authorities1
Is the Herbal Substance on the market? No
Combination products: Herbal teas (authorised since 1999)
Average number of combination substances: >5
What are the main combination substances? Flipendulae ulmariae herba, Equiseti herba, Harpagophyti radix, Salicis cortex, Solidaginis virgaureae herba, Callunae herba
Indications: as an adjuvant for inflammatory and degenerative diseases of locomotor apparatus (rheumatism, arthrosis, arthritis and gout), adjuvant therapy in flu like symptoms.
Is the Herbal Substance on the market? No
Note that the Viola tricolor is accepted by the Food Agency in Denmark in food supplements (at least 100 mg).
Is the Herbal Substance on the market? Yes
Status: Registered products
Preparations: Dry aqueous extract (6:1), 62.5 mg per tablet (equivalent to 375 mg of herb) Since when are the preparations on the market? > 40 years
Pharmaceutical form (Standard Terms): Dry aqueous extract (6:1), 62.5 mg per tablet (equivalent to 375 mg herb)
Posology: Tablets: 2 tablets/3 times daily
Combination products: The herbal substance is available in 2 combination products Average number of combination substances: 2 – 3
What are the main combination substances? Burdock root
1 The data are collected using the template entitled ‘Document for information exchange for the preparation of the assessment report for the development of Community monographs and for inclusion of herbal substance(s), preparation(s) or combinations thereof in the list’ (EMEA/HMPC/137093/2006)
Indications: Traditional remedy for spots, skin blemishes and dry eczema
Registration was granted in the old legislative frame, >40 years ago
Children: Not recommended
Contraindications: Known hypersensitivity to any of the ingredients
Is the Herbal Substance on the market? Yes
Status: Registered products
Pharmaceutical form (Standard Terms): Comminuted herbal substance for infusion Since when are the preparations on the market? > 30 years
The herb is present in the market as single active ingredient only.
There are 10 registered herbal teas.
1)Oral use: 1 teaspoon or sachet (1.5g of herb) for tea preparation/ 150 ml of hot water for 5 – 7 minutes
Adults and children over 12 years of age: 1 cup 3 times daily
2)Cutaneous use: 6 g (3 sachets) of herb for infusion in 250 ml of hot water for 5 – 7 minutes Several times daily as a wet dressing
Additional comments: Violae tricoloris herba has been a subject of Polish Pharmacopoeia since 1937; recommended dosage in the last versions of the Polish Pharmacopoeia: single dose of herbal substance for oral use 3 g and for topical use 3 – 10%, daily dose for oral use 10 g. Posology: In mild seborrhoeic skin condition for cutaneous use. Oral use in mild seborrhoeic skin condition and as diuretic
Polish name of the herbal substance: ziele fiołka trójbarwnego.
Is the Herbal Substance on the market? Yes
Preparations: Comminuted herbal substance
Since when are the preparations on the market? 1991
Pharmaceutical form (Standard Terms): Comminuted herbal substance, capsules of 200 mg
Capsules: 1 or 2 capsules/3 times daily*
Indications: Dry cough or common cold
*Registration was granted in the old legislative frame, in 1991, not in the 2004/24/EC Combination products: The herbal substance is available in 2 combination products Average number of combination substances: 3 – 5
Posology for combination products: 1) dry cough or common cold 2) acne
Regulatory status overview
MA: Marketing Authorisation TRAD: Traditional Use Registration
Other TRAD: Other national Traditional systems of registration Other: If known, it should be specified or otherwise add ’Not Known’
This regulatory overview is not legally binding and does not necessarily reflect the legal status of the products in the MSs concerned.
1.3. Search and assessment methodology
Databases assessed up to May 2010: Science Direct, PubMed, Embase, Medline, Academic Search
2. Historical data on medicinal use
2.1. Information on period of medicinal use in the Community
The traditional use of wild pansy goes back to ancient times. Wild pansy preparations were used during the Middle Ages mainly as a remedy for various skin ailments and were mentioned according to Madaus (1938) by Lonicerus 1564; Hieronimus Bock 1565, Matthiolus
Wild pansy was most often recommended for cutaneous and internal use in various skin disorders (Köhler 1883, Dragendorff 1898, Schimpfky 1900; Hoppe 1951, Hoppe 1958, Martindale 2009, PDR 2000; 2004; Chevallier 1996); especially those of a seborrhoeal nature (Martindale 2009), including weeping and dry eczema (Hänsel et al. 1994, Köhler 1883, Madaus 1938, Ożarowski 1976; Roeske 1955; Schöpke et al. 1993, British Herbal Pharmacopoeia 1996), impetigo, acne, and pruritus (Braun 1974, Wichtl 1994; 2004), also in irritation and vulvular itching, skin rashes and eruptions (PDR 2000; 2004, Hänsel et al. 1994), and skin ulcers (Hoppe 1951, Hoppe 1958). Wild pansy was used in paediatric practice for treatment of various rashes and eruptions, eczema (Hoppe 1951, Hoppe 1958), and/or the treatment of seborrhea of the scalp of newborn infants (crusta lactea) (Rimkiene et al. 2003; Bundesanzeiger 1986). An ethnobotanical study indicates that the infusion of the whole plant (Viola tricolor L.) imbibed or applied externally is used in psoriasis (Amenta 2000).
Use for other purposes:
Respiratory tract disorders
In traditional medicine wild pansy was recommended internally, as expectorant (Hoppe 1951, Hoppe 1958; Kuźnicka and Dziak 1970; Muszyński 1954; Ożarowski 1976; Roeske 1955) for catarrhs of the respiratory tract (Hänsel et al. 1994, Rimkiene et al. 2003), coughs, whooping cough (Hänsel et al.
1994, Rimkiene et al. 2003) and in the treatment of acute bronchitis, inflammation of the throat and feverish colds (Hänsel et al. 1994; PDR 2000; 2004,Wichtl 1994; 2004).
Traditionally wild pansy is used as a diuretic (Hoppe 1951, Hoppe 1958, Bobowska et al. 1975; Kuźnicka and Dziak 1970; Muszyński 1954; Ożarowski et al. 1978; Wichtl 1994; 2004, Hänsel et al. 1994) in urinary tract disorders including cystitis and dysuria (Hoppe 1951, Hoppe 1958; Rimkiene et al. 2003).
In traditional medicine wild pansy is considered to be a
2004, PDR 2000; 2004) as well as for rheumatic complaints, gout, and arteriosclerosis (Hänsel et al. 1994; Hoppe 1951, Hoppe 1958; Kuźnicka and Dziak 1970; Muszyński 1954; Wichtl 1994; 2004).
In traditional medicine wild pansy is also used in varicose ulcers, capillary fragility, haemorrhoids (Rimkiene et al. 2003; Hoppe 1951, Hoppe 1958) and gastrointestinal disorders (Hoppe 1951, Hoppe 1958). It was also proposed as a mild laxative (Dragendorff 1898, PDR 2000; 2002; Wichtl 1994; 2004).
Viola tricolor is contemporary used in folk medicine in Bulgaria as antitussive, diuretic, in skin disorders against dermatitis, against atherosclerosis and in Italy against psoriasis (Ivancheva and Stantcheva 2000; Leporatti and Ivancheva 2003).
Viola tricolor has been used for more than thirty years in Community, mainly as a remedy for various skin ailments, especially those of a seborrheal nature (Bradley 2006; Chevallier 1996; ESCOP 2009; Martindale 2009; PDR 2000; 2004).
2.2.Information on traditional/current indications and specified substances/preparations
2.3.Specified strength/posology/route of administration/duration of use for relevant preparations and indications
Bundesanzeiger No 50: 13.03.1986, Violae tricoloris herba
External use: Comminuted herb: infusum 1.5g/cup of water, 3 times daily.
Hänsel et al. (1994)
Internal use: Comminuted herbal substance
Tea: 1 g comminuted herbal substance in 1 cup (250 ml) of boiling water. Daily dose: 1 cup 3 times daily.
Infusion for oral use: 5 – 10 g of comminuted herbal substance for 1 litre of boiling water.
Use 1 dessert spoon 3 times daily.
Tea: 1 g of comminuted herbal substance for 1 cup of boiling water. Drink 3 times daily after meal intake.
Pulverised herbal substance: Half of teaspoon of pulverised herbal substance 3 times daily in hot sugar water.
Cutaneous use: For topical use: 4g of herb /150 ml of boiling water, also for bath additive.
Kraft and Hobbs (2004)
Wild pansy is used in skin inflammations (milk crust and mild seborrheal conditions). Wild pansy is also indicated in pruritus due to allergy, eczema and old age related itching, and itching associated with liver or kidney diseases.
One teaspoon comminuted herb in 1 cup of hot water for 5 minutes. Apply as a wet dressing to the affected areas of the skin 2 to 3 times daily.
Wild pansy flowering aerial parts (Viola herba cum flore) is used topically for minor skin disorders, particularly in seborrhoea. It is also used orally for gastrointestinal and respiratory tract disorders.
PDR for Herbal Medicines (2000, 2004)
Comminuted herbal substance for infusion, decoction. It is also available in ointments and shampoos for external use.
Polish Pharmacopoeia (1954, 1999)
Single oral dose: 3 g of comminuted herbal substance in decoction. Daily oral dose: 10 g.
2.4. Overall conclusion on the traditional medicinal use
Viola tricolor is a well known traditional herbal medicinal product used for centuries in Europe. Its medicinal use was described in many well known published manuscripts and textbooks.
3.1. Overview of available pharmacological data regarding the herbal substance(s), herbal preparation(s) and relevant constituents thereof
Constituents of the aerial parts of Viola tricolor L. are received by Fraisse et al. 2001.
The quantity of flavonoids in the herb Viola tricolor and Viola arvensis is 2.1% and 1.3% respectively (Manez and Villar 1989; Papp et al. 2004;
Other flavonoids: apigenin
The highest concentration of rutin is usually found in the flowers (Hänsel et al 1994).
In a variety of Viola tricolor not used in therapy, flowers are reported to contain a remarkable amount 18 – 21 % of rutin. In other subspecies: Viola tricolor L. var. maxima hort. yellow flowers rutin concentration varies, in yellow flowers there is 15.96% of rutin and in white only 4.63% (Zielińska- Sowicka 1972). The other data (Gertig et al. 1966) present values of 4.5 – 10.5% in all flowers and in herb without flowers only 1.7% of rutin content.
Sixteen flavonoid glycosides have been separated from the methanol extract of wild pansy by micro- liquid chromatography: four flavonol
The mucilage content in wild pansy herb is about 10%. Hydrolysis of polysaccharides results in glucose (35.1%), galactose (33.3%), arabinose (18.1%), rhamnose (8.4%), uronic acid (6.2%) and xylose (5.1%) residues (Franz 1969).
The water soluble fraction of polysaccharides is composed of glucose, galactose and arabinose residues (2:1.8:1.1) and galacturonic acid, rhamnose and xylose. The pectin fraction contains galacturonic acid, glucose, and galactose (Zabaznaya 1985, Hänsel et al. 1994). According to Deters, the polysaccharides of wild pansy are mainly composed of galactose, glucose, galacturonic acid (34:29:27), whereas arabinose, rhamnose and mannose are minor components (7:2:1) (Deters 2005).
The content is about 0.18%, including
The content is reported with 0.0086%, containing methyl salicylate as a principal constituent (Hänsel et al. 1994).
In wild pansy flowers occurs
Yellow blossoms yield carotenoids (9.69 mg/g dry wt.), mainly
According to Hansmann and Kleinig (1982) the violaxanthin (about 75% of total carotenoids), occurs mainly as diesters, while monoesters and free violaxanthin are only present in trace amounts. The violaxanthin is esterified with the usual saturated acids (12:0, 14:0, 16:0, 18:0 acids) but also β– hydroxy polar 12:0, 14:0, 16:0 acids. In the latter
Main pigment which is responsible for the violet colour of flowers of Viola tricolor is composed essentially of violanin (ca 33%), a derivative of delphinidin with
Cyclotides (macrocyclic peptides)
Presence of violapeptide I, composed of 28 amino acids and showing hemolytic activity, in Viola arvensis Murray but not in Viola tricolor, was described in 1993 by Schöpke et al. Cyclotides (macrocyclic polypeptides), named vitri A and varv peptides A – H, have been first isolated from aerial parts of Viola arvensis. Each consists of 29 – 30 amino acids covalently cyclized via the amide backbone and by three disulphide bridges forming a cystine knotted arrangement (Claeson et al. 1998, Göransson et al. 1999; Trabi and Craik 2002; Xu et al. 2008).
According to Göransson et al. (2003; 2004), cyclotides expression profiles by
The number of cyclotides in the Violaceae plant family is coming close in estimation to >9000 (Simonsen et al. 2005). They display a range of biological activities including uterotonic, haemolytic, cytotoxic, antimicrobial,
Tocopherols (30.2 mg% dry weight) in flowers (Baszyński 1961); coumarins with umbelliferone (Wichtl 1994; 2004) and xanthine derivatives (Schöpke 1993). Vitamin C content in fresh, flowering herb is 198 mg/100g, in dry herb 689.6 mg/100g (Hänsel et al. 1994), tannins (2.4 – 4.5 %),
Triacyl glycerols (57%) carotenoids and their esters (23%) are the main constituents and polar lipids, proteins, alkanes, phytol esters, plastid quinones and steryl esters have been detected in smaller amounts in plastoglobules isolated from petals of Viola tricolor L. (Hansmann and Sitte 1982).
In vitro experiments
In a screening programme to evaluate several plants used in an Italian traditional medicine for gastrointestinal and respiratory tract complaints a hydromethanolic
The reported presence of triterpene saponins in Viola tricolor herba from dry plant material (5.2% yield) with a haemolytic activity (in vitro; the haemolytic index IH=4000) (Tamas et al. 1981) was not confirmed in a later investigation (Schöpke et al. 1993, Hänsel et al. 1994). The haemolytic activity of Viola arvensis extracts is rather due to presence of the partly examined peptide violapeptide I (composed of 28 amino acids) isolated from Viola arvensis leaf (but not detected in Viola tricolor). Whether it is a cyclotide it is not completely clear (Schöpke et al. 1993, Wichtl 1994; 2004).
However, a case of haemolysis was presented in a 9
Three cyclotides, vitri A, varv A and varv E, isolated from aerial parts of Viola tricolor exhibited dose- dependent cytotoxic activity against two human cancer cell lines
10 – 90% response interval in the log
In other experiments Lindholm et al. (2002) described cytotoxic activity of cyclotides varv A and varv F obtained from Viola arvensis Murr. Their activity was tested in several human tumour cell lines and also in primary ovarian carcinoma cells obtained during surgical procedure and lymphocytic leukemia cells isolated from bone marrow or peripheral blood. Both varv A and varv F induced potent cytotoxic effect in tumour cell lines with IC50 values ranged from 2.73 – 7.49 M. Cyclotide varv A presented potent cytotoxic activity in primary cultures of human tumour cells with selective toxicity to haematological chronic lymphocytic leukaemia cells (IC50 = 1.34 M). The activity profiles of cyclotides were not correlated to the profiles of standard anticancer drugs: doxorubicin, vincristine, cytarabine, melphalan and topotecan. The authors suggest that the cytotoxic mechanism of action of cyclotides differs from that of the standard drugs used in cancer treatment.
Deters et al. (2005) showed significant reduction of proliferation but improvement of the cell viability of human keratinocytes in vitro with wild pansy oligo and polysaccharides. Tests were performed on primary human keratinocytes (NHK) cells and spontaneously immortalised cell line HaCaT. Viola tricolor
concentration 10 g/ml. However they induced mitochondrial dehydrogenase activity in viable NHK and HaCaT cells (p<0.05).
Antithrombin and anticancer activity
The methylene chloride and methanolic extracts of forty five plants of Russia, were used to determine antithrombin and anticancer activity, Viola tricolor L. var. hortensis included. Antithrombin activity of the methylene chloride extract of Viola tricolor was the most potent and displayed 93% activity, whereas the methanolic extract only exhibited 31% activity.
For cytotoxicity tests the mouse leukaemia cell line (L1210) was used. Again, the methylene chloride extract of Viola tricolor induced 79% inhibition of growth of leukaemia cells, whereas the methanolic extract inhibited the growth of 49% of cells (Goun et al. 2002).
Mantle et al. (2000) compared relative antioxidant activities of British medicinal plants, Viola tricolor L. included. Antioxidative activity of the plants was tested through competitive scavenging of the ABTS•+
Antioxidant activity (mM TE/g dry weight) of fresh tissue Viola tricolor leaf was 1.46±0.32, whereas for flowers was 1.43±0.26. This activity was quite potent, as comparable extracts of Ginkgo biloba gave values of 0.62 and 0.61 mM TE/g dry weight, respectively.
The infusion, decoction and ethanolic extract of Viola tricolor herb displayed significant inhibitory activity against Staphylococcus aureus, Bacillus cereus, Staphylococcus epidermidis and Candida albicans and moderate activity against Pseudomonas aeruginosa, Enterococcus faecalis, Escherichia coli and Klebsiella pneumoniae. The dichloromethane, ethyl acetate and methanolic fractions obtained by partitioning of Soxhlet of dried plant material, showed the lower activity.
The higher activity of the extracts containing complexes of components of the plant, relative to that of the fractions comprising compounds of different polarity, suggest a synergism in antibacterial action between compounds of wild pansy (Table 1,
Antimicrobial activity of infusion, decoction, ethanolic extract (EtOH) and dichloromethane (CH2Cl2), ethyl acetate (EtOAc), methanolic (MeOH) fractions of Viola tricolor herba
aMIC (minimal inhibitory concentration, mg/ml), MBC (minimal bactericidal concentration, mg/ml).
MIC of standards – Gentamicin:
Staphylococcus aureus, Bacillus cereus, Staphylococcus epidermidis and Candida albicans and moderate activity against Pseudomonas aeruginosa, Enterococcus faecalis, Escherichia coli and Klebsiella pneumoniae. The dichloromethane, ethyl acetate and methanolic fractions obtained whilst the antibacterial activity is relatively weak this goes some way to supporting the traditional uses of wild pansy for skin conditions.
In vivo experiments:
Influence on heart contractility.
Pápay et al. (1987) tested different fractions obtained from Viola tricolor in a model heart contractility in rats induced by intravenous vasopressin administration. Several extracts of wild pansy (ethyl alcohol,
In an earlier experiment, eczema was induced in rats by prolonged feeding with rye (Secale cereale). After a diet augmented with fresh wild pansy given for 2 months (no information about the amount ingested), marked improvement of the skin condition was observed in comparison with control animals (Madaus 1938).
In another early experiment Vollmer and Weidlich (1937) showed no diuretic activity of Violae tricoloris herba. When administered orally to rabbits at 2.5 – 7.5 g/day or to mice at 50 – 200 mg/day wild pansy did not influence urine volume; in mice at the dose of 200 mg/day, however chloride excretion in urine increased by 108%.
3.2. Overview of available pharmacokinetic data regarding the herbal substance(s), herbal preparation(s) and relevant constituents thereof
Due to lack of data on pharmacokinetics no conclusions can be drawn.
3.3. Overview of available toxicological data regarding the herbal substance(s)/herbal preparation(s) and constituents thereof
There is no serious concern about toxicity of wild pansy herb.
Due to the lack of data on acute and chronic toxicity, repeated dose toxicity, mutagenicity, carcinogenicity, reproductive and developmental toxicity, a list entry for Viola tricolor herba cum flore cannot be recommended.
3.4. Overall conclusions on
Experimental preclinical data show antioxidant, antibacterial, diuretic, antithrombin and anti- inflammatory activity in skin conditions. Results of antimicrobial evaluation in vitro activity of Viola tricolor extracts support the traditional use of wild pansy even though the effects are relatively weak compared to standard antibiotics.
4. Clinical Data
4.1. Clinical Pharmacology
4.1.1. Overview of pharmacodynamic data regarding the herbal substance(s)/preparation(s) including data on relevant constituents
There are no data on human pharmacodynamics.
4.1.2. Overview of pharmacokinetic data regarding the herbal substance(s)/preparation(s) including data on relevant constituents
There are no data on human pharmacokinetics.
4.2. Clinical Efficacy
4.2.1. Dose response studies
There are no
4.2.2. Clinical studies (case studies and clinical trials)
None were published on
Combination products studies
The study was performed on 88 patients between 18 – 65 years of age with mild to moderate atopic dermatitis in dermatology practice. They were treated for 4 weeks with an ointment containing
Mahonia aquifolium, Viola tricolor and Centella asiatica alcohol extracts (5g of each /100 g of ointment).
After 4 weeks of treatment the ointment reduced the primary (erythema, oedema/papulation, oozing/crust, excoriation and lichenification) and secondary endpoints (pruritus, global assessment of effectiveness and tolerability) slightly more than the base cream which was used as vehicle, but the difference was not statistically significant.
In this trial, an ointment could not be proven to be superior to a base cream with mild to moderate atopic dermatitis. However, a subanalysis indicated that the cream might be useful under conditions of cold and dry weather (Klövekorn et al. 2007).
4.2.3. Clinical studies in special populations (e.g. elderly and children)
No information available.
4.3. Overall conclusions on clinical pharmacology and efficacy
There are no clinical trials available on Viola tricolor herba cum flore.
5. Clinical Safety/Pharmacovigilance
There are no adverse effects reported from the Member States, however allergic reactions to Violaceae family should be considered.
5.1. Overview of toxicological/safety data from clinical trials in humans
There are no clinical trials available.
5.2. Patient exposure
5.3. Adverse events and serious adverse events and deaths
Haemolysis was reported in a
Wild pansy belongs to herbs to be used with caution, due to salicylates content (Brinker 2001).
5.4. Laboratory findings
No data available.
5.5. Safety in special populations and situations
Intrinsic (including elderly and children) /extrinsic factors
The use of wild pansy is not recommended in children younger than 12 years of age due to lack of available data.
Patients with 6GTP deficiency can be at risk of haemolysis after Viola tricolor treatment.
Use in pregnancy and lactation
The wild pansy should not be used during pregnancy and lactation due to the lack of safety information.
Drug abuse, Withdrawal and rebound
Effects on ability to drive or operate machinery or impairment of mental ability
5.6. Overall conclusions on clinical safety
There are no reports of adverse effects of wild pansy herb from Member States, however allergic reactions to Violaceae family should be considered.
Case of transient haemolysis in
6. Overall conclusions
The available data are sufficient to support the traditional uses of Viola tricolor herb in the European Community.
Viola tricolor herba cum flore fullfils the requirement of therapeutic use for at least 30 years (15 years within the community, Directive 2004/24/EC).
Traditional herbal medicinal product for symptomatic treatment of mild seborrhoeic skin conditions.
Due to the lack of data on acute and chronic toxicity, repeated dose toxicity, mutagenicity, carcinogenicity, reproductive and developmental toxicity, a list entry for Viola tricolor can not be recommended.