by Fatimah Qassadi

Ivy is a familiar sight in yards, houses and on the walls of buildings, and is found widely on and around Mecklenburgh Square Gardens. Many people favour this popular ornamental plant because it makes an attractive ground cover and beautifies facades since it stays green all year. Not surprisingly, this popular plant is not only used for decoration purposes, it was also widely used in ancient times as a pain reliever and burns ointment. Today, there are authorized products in the herbal medicine market containing ivy leaf extracts, which claim to treat bronchitis and the cough associated with the common cold. However, more research is needed to prove its antimicrobial and anti-inflammatory benefits. So, let us explore this popular plant historically and clinically.

Introduction

Ivy (Hederae helix L., folium) is an evergreen, flowering and fast-growing plant of the Araliaceae family (see image to the right). Common names include ivy, European ivy, English ivy and common ivy, and lablab (اللبلاب) in Arabic. H. helix is a fast-growing, perennial plant that is mostly grown as a climbing vine or rambling groundcover. It may grow to 20–30 m in height; however, it also forms carpets where there are no suitable objects to climb (Lutsenko et al. 2012).

There are two growth stages for ivy to grow. The first is when thick, three-lobed dark leaves on the aerial root are produced, which make the ivy cling strongly to a suitable surface such as a tree, cliff or wall (Rosca-Casian et al. 2017).

This stage is called the climbing or spreading stage and is what is most commonly seen (see image belowt). The second stage is the ‘adult’ stage, which is described as a shrubby non-climbing stage (see image below) (Patch 2004; Quiver 1864). In this stage, green leaves that are unlobed and elliptic-ovate in shape appear on rootless stems that do not spread or climb but do produce small, greenish-yellow flowers followed by black berries with stone-like seeds (Metcalfe 2005). Ivy flowers are produced from late summer to autumn and occur as umbrella-like clusters with alternate, small, leathery, dark-green leaves.

The ivy fruits are purple or black berries, which are considered a food source for many insects, including bees. Berries can be eaten by birds, which aids in their dispersal. Humans also disperse ivy seeds.

The ivy plant is widespread throughout Britain and is one of only a few native evergreen shrub (Quiver 1864). It is also indigenous to Northern Africa, Continental Europe and Russia and is distributed worldwide, especially in moist, shaded areas in temperate climates. Ivy plants prefer to grow in shady areas where the soil is mostly moist. Humans have helped spread ivy to other areas. For example, ivy was grown in the United States, South America and Australia by settlers and continues to be widely sold in the US as an ornamental plant (Scott 2010; Bossard 2000; Bunk et al. 2019). English ivy is considered a long-lived plant that can be fully mature in 10 years. In England, 100-year-old ivy plants have been documented and one has been recorded at over 400 years of age (Patch 2004).

Historically, ivy was associated with Bacchus, the god of agriculture, wine and fertility in Roman mythology. In medieval England, wearing a wreath of ivy leaves was supposed to prevent intoxication. These ancient meanings later became embedded in our culture and are deeply reflected in the modern use of ivy. The dense growth and abundant leaves of H. helix, which appear as small umbrellas from the stem, make ivy a desirable houseplant and for decoration on the outer walls of houses during mid-winter. It is also traditionally used in Christmas festivities. Phytochemical studies have studied ivy leaf extracts and isolated the active constituents responsible for its therapeutic effects. Its medicinal benefits are linked to specific metabolites, such as terpenoids and specifically saponins (α-hederin, hederacoside C and hederagenin). Ivy can grow in any yard or garden, including the fascinating Mecklenburgh Square Garden, given its versatility, low maintenance and fast growth.

Popular history and contemporary uses

Since ancient times, ivy has been of major cultural and symbolic importance and was part of a rich mythology. Ivy played a notable role in Greek and Roman mythology (Smith et al. 1890). The ancient Greek god Dionysus was the god of wine, festivity, agriculture and pleasure. He was crowned with a wreath of ivy, which grew abundantly across his homeland. In ancient Roman mythology, Bacchus was often connected to ivy leaves, perhaps because it was once thought that ivy plants could prevent intoxication and cure hangovers (Theoi 2000a). In the middle ages, this belief reached England, where people displayed a branch of ivy leaves above their doors to symbolize the high quality of their wine (Theoi 2000b). In old Ireland, ivy was thought to be a symbol that could protect against evil when it grew near houses and, if it fell or died, the residents would suffer misfortune (Smith et al. 1890).

Ivy also represented good luck and was often carried by young ladies to festivals to bring peace and luck. Not only was it worn by young women, poets also wore a crown of ivy leaves for inspiration and motivation. There is another myth related to the Greek God of Marriage, Hymenaiose, who had ivy growing around his altar (Quiver 1864). This myth considered ivy a symbol of eternal life, fidelity and loyalty, so wreaths of ivy were often given to the bride and groom on their wedding day.

These ancient meanings are reflected in modern cultural life as ivy plants are widely used as decorative and ornamental plants thanks to their beautiful appearance on the walls of buildings. Ivy’s evergreen nature makes it a great favourite for Christmas decorations (Bossard 2000; Quiver 1864). It is a fascinating plant that can be a valuable part of its environment or an invasive intruder. Some people favour ivy as an ornamental plant for decorating both the outside and inside of their house, because of its characteristic features. Other people dislike this plant for its fast-growing and invasive properties that can block light and air and smother other growing trees (Melzer et al. 2012; Scott 2010). In any case, with its rich history, ancient cultural meanings and proven therapeutic benefits, ivy is hard to ignore.

Traditional medicinal use

Ivy leaf was noticeable for many years and made it highly popular among traditional healers. Ivy, with its symbolic importance, has numerous medicinal benefits. Hippocrates used ivy to reduce inflammation and as an anaesthetic for minor surgery (Schmidt et al. 2012). It was traditionally used internally and externally for many different disorders.

Ethnopharmacological research has shown that ivy has very different indications, for example, for jaundice and dysentery (Maduse 1938). Also, it has been recommended for treating bile and liver dysfunction if taken orally as an infusion. Ivy leaves and berries have been used widely for common cold-associated coughs and chronic coughs associated with sputum production, bronchitis and, especially, whooping cough (Kim et al. 2017). Ivy was the focus of many clinical studies by the French physician Leuret, who succeeded in exploring its mechanisms of action (Steinmetz 1961).

Ivy has been reported to have the ability to normalize hypertensive states within a few days and without recurrence when taken daily as a tincture. The dose for this indication is five to fifteen drops in children and up to fifty drops in adult patients (Steinmetz 1961). Externally, it has been used in folk medicine for treating rheumatic complaints. The pounded leaves were also used as a soothing ointment and treatment for benign warts, parasitic disorders, burn wounds, cellulitis, lesions, ulcers and chapped skin (Gul et al. 2019).

In central Italy, people used the boiled leaves of H. helix to treat skin ailments and fight scabies and worms (Chichiricco et al. 1980). Brussell (2004) noted that some people in Greece drink red wine with ivy leaves that have been crushed and stored for two weeks. This famous traditional beverage was believed to have the ability to treat depression by working as stimulant and narcotic. In Turkey, leaves of H. helix were prepared as a decoction for diabetic patients (Kultur 2007). One teacup was taken by the patients twice a day for one week, which was believed to have purifying and detoxifying effects.

Scientific Evidence

Phytochemistry: What active components are present in ivy?
The plant has been investigated regarding its chemical compounds. Phytochemical analysis shows that the plant contains triterpene saponins, flavonoids, unsaturated sterols and alkaloids (Bedir et al. 2000; Mahran et al. 1975). These phytochemicals play a critical role in plant defence processes but do not have a primary role in plant growth. Triterpene saponins, which are believed to be the compounds responsible for H. helix’s therapeutic activities, have been isolated from the fruit and leaves. These saponins include aglycone hederagenin, hederosaponin C and α-hederin (Yu et al. 2016). Also, ivy contains volatile oils such as β-caryophyllene, β-pinene, limonene and falcarinol. In addition to flavonoids, alkaloid compounds, specifically emetine, are present in the plant, as are vitamins E and C and pro-vitamin A (Trute & Nahrstedt 1997).

Pharmacology and pre-clinical data

Bronchodilatory and secretolytic effects
Ivy leaves have traditionally been used to make breathing easier by loosening up mucus so that it clears out faster, relaxing airway muscles and reducing cough. This is specifically helpful for people suffering from asthma, bronchitis and allergies. Many studies have tested these activities (Kim et al. 2017; Song et al. 2015; Holzinger & Chenot 2011). Saponins, in particular, α-hederin, which arises from hederacoside C, could be responsible for the bronchodilatory and secretolytic effects of ivy extract (Sieben et al. 2009). An experiment using the saponins present in ivy leaf was conducted by Trute et al. (1997). They observed that ivy leaf extract exhibited spasmolytic activity by inhibiting the bronchoconstriction effect, providing evidence of ivy’s ability to dilate smooth muscles and prevent bronchial constriction.

Other studies have supported this notion; the results of one study showed that ivy leaf extract prevented smooth muscle constriction and caused bronchorelaxation of smooth muscles (Gepdiremen et al. 2005). The research found that α-hederin exhibited its secrolytic and bronchodilatory effects by activation of special receptors in the smooth muscle cells of bronchi called“β2-adrenergic receptors. This leads to a relaxation of these muscles and results in the release of compounds that act as mucus lytics (Sieben et al. 2009). Song et al. (2015) investigated the effect of dry ivy extract as an antitussive and expectorant in combination with barabrein, a compound with bronchodilatory activity found in Rhizoma captides. The results show that this mixture works better as a cough treatment with expectorant activity than each extract alone. However, no substantial benefit over conventional treatment has been demonstrated since, in most studies, control groups were not used.

Anti-inflammatory and analgesic effects

English ivy extract may be useful for people with arthritis and inflammation (Gepdiremen et al. 2005; Suleyman et al. 2003). Thus, ivy extract has been evaluated for its anti-inflammatory potential in mice (Rai 2013). The study suggested that ivy might have an anti-inflammatory effect, as it caused noticeable declines in inflammation and arthritis over seven days of treatment. The effect of the extract was close to that of diclofenac, an anti-inflammatory drug commonly used for reducing inflammation and arthritic pain; inhibition of inflammation was 88.89%, compared with 94.44% for diclofenac. Animal testing has been used to demonstrate that swelling and inflammation associated with allergies are reduced when ivy leaf extract is administered. This activity may be due to blocking of histamine, which is a chemical compound released by the body in response to allergic reactions (Gepdiremen et al. 2005); however, clinical proof is limited.

Anti-microbial and anti-fungal effects

Some studies have found that ivy has antimicrobial effects, specifically on gram-positive bacteria, including Staphylococcus aureus, as well as an antimycotic effect on yeast and other fungi (Cioaca et al. 1978; Rosca-Casian et al. 2017). Other studies tested ivy extract in vivo and in vitro for its potential anti-fungal effect in mice infected with Candida albicans (Bedir et al. 2000; Rosca-Casian et al. 2017; Parvu et al. 2015). This is thought to be due to saponins. Saponin mixture isolated from ivy leaves succeeded in eliminating Candida infection in 90% of mice within seven days of treatment, and 100% within ten days (Timon-David et al. 1980). Although these studies were mainly conducted in animals, their results suggest that ivy extract might have potential activity against microbial infections and may be a cost-effective treatment. However, studies on humans are needed to confirm the efficacy and safety profile of ivy.

Clinical Evidence

Ivy leaf extract made a name for itself in the treatment of bronchitis. The term bronchitis includes all illnesses characterized by coughing and expectoration. Research on ivy aimed to test its expectorant and bronchodilatory properties, particularly in relation to saponins content, and α-hederin in particular. One randomized controlled trial compared ivy extract to a placebo as a treatment for acute bronchitis associated with productive cough. However, in this study, ivy extract was combined with thyme extract in a commercial product named Bronchipret syrup (Kemmerich et al. 2006). There was a noticeable reduction in coughing frequency with more rapid regression of symptoms and earlier onset of recovery at about six days in the ivy/thyme treatment group in contrast to eight days in the control group. The treatment was well tolerated with no serious adverse effects (Seibel et al. 2015). Notably, this was the first study that reported the superiority of ivy extract over placebo in treating acute bronchitis. However, this positive effect might have been achieved by a synergistic action with thyme extract, which has been reported to have bronchodilatory and expectorant properties (Wagner 2009). So, it remains uncertain as to whether the reported effect was associated with ivy alone or in combination with thyme.

A comparative study by Meyer-Wegener et al. (1993) investigated H. helix’s efficacy in treating chronic bronchitis. The study compared ivy extract with a synthetic drug, Ambroxol, which is used for mucolytic therapy in bronchitis disease (Guo et al. 2006; Holzinger & Chenot 2011). Ivy extract improved bronchitis symptoms, including sputum production, coughing and difficulty of breathing. However, these benefits were only demonstrated in the short term as the treatment was conducted for four weeks. It should be noted that this duration is not in line with the definition of chronic disease. Thus, using ivy extract as a bronchodilator for chronic bronchitis cannot be recommended based on this study.

Bolbot et al. (2004) compared ivy extract with a popular conventional expectorant therapy for acute bronchitis called acetylcysteine in the Ukraine. The study population was comprised two groups of children with persistent cough associated with acute bronchitis. They were given one of the treatments for 7 to 10 days. In both groups, cough and shortness of breath symptoms were improved. However, patients in the ivy treatment group showed better improvement in lung function compared to the acetylcysteine group. Still, we cannot rely on the results of this study since it had many methodological flaws such as a small sample size, undefined selection criteria and unclear clinical endpoints.

A double-blind trial of 590 patients in Germany compared the effects of two ivy leaf extracts on acute bronchitis. Both treatments improved symptoms such as sputum production, chest pain during coughing and dyspnoea. In addition, the study showed a favourable safety profile with adverse effects limited to mild gastrointestinal symptoms (Cwientzek et al. 2011). Another study found a significant improvement in bronchitis symptoms after 7 days of treatment with a syrup containing dried ivy leaf extract (Fazio et al. 2009). This clinical trial tested the efficacy of the treatment on a large sample—a total of 9,657 adults and children—with 95% of patients showing significant improvement.

Initial reports from two non-interventional studies of the efficacy and tolerability of two ivy formulations (syrup and drops) in 268 children aged 0–12 years with cough and bronchitis indicate that clinical symptoms such as rhinitis, cough, pain on coughing, chills and mucus production were improved (Schmidt et al. 2012). No serious adverse effects were reported in either study. Since both studies lacked placebo or intervention groups, comparing the efficacy of the different formulations is impossible. However, there were no clinically relevant differences in symptomatic improvement between the formulations. A trial carried out in Germany found that a treatment with film-coated tablets containing dry ivy leaf extract showed good to very good tolerability according to questionnaire-based ratings by 330 patients (Stauss-Grabo et al. 2011).

There were no serious adverse reactions except in one trial where a patient experienced exacerbation of existing cutaneous dermatitis. These results demonstrate that ivy leaf extract has therapeutic activity for bronchoconstriction in patients with bronchitis. However, treatment of chronic bronchitis symptoms requires long-term efficacy and tolerance to avoid exacerbation and progression of respiratory distress. None of these studies has tested ivy extracts over long periods. The small sample sizes of most trials and a lack of placebo-controlled and double-blind studies are significant limitations of current research into using ivy for chronic respiratory diseases. As a result, more studies are needed using larger sample sizes to assess the effectiveness of ivy in treating chronic bronchitis.

Safety

Ivy, in general, is safe when properly employed and when recommended doses are administered. Thus, standardized extracts with known concentrations of active substances that are chosen for their effectiveness and safety and regulated to be used medicinally are generally considered to be safe. The German Commission E Monographs and European Medicines Agency (EMA) has confirmed ivy leaf as a treatment for productive cough and spastic bronchitis. Since the quality of commercial herbal products should be taken into account, ivy leaf extract has been regulated and registered in Europe under the the Traditional Herbal Registration (THR) directive to ensure it is of high quality with standardized active ingredients and has rigorous market regulation. The well-established use of ivy is based on scientific studies confirming its effectiveness and safety profile. However, evidence to support its use in children is insufficient, and using ivy in children below 12 years of age is not recommended. Although there are no serious adverse reactions reported for ivy leaf, allergic contact dermatitis might occur in people with frequent exposure to ivy due to the presence of two allergenic compounds: falcarinol and didehydrofalcarinol (Hausen et al. 1987; Jones et al. 2009; Boyle & Harman 1985). One study evaluated the effect of ivy on the skin of patients with existing cutaneous dermatitis. The study concluded that patients with acute dermatitis could be sensitized by ivy leaf extract more than nine-times more than any other plant (Rosas-Alvarado & Morfin-Maciel 2013).

People with frequent exposure to ivy, such as gardeners and florists, might experience allergic symptoms such as asthmatic bronchitis, allergic rhino-conjunctivitis and cutaneous symptoms (Paulsen et al. 2010; Jors 2003). Such people should wear appropriate protective clothing and gloves when working with ivy. Special care should also be taken with children when they are climbing in trees covered with ivy to avoid any potential allergic reaction that might occur following contact. Furthermore, there is a risk of cross-reaction when another plant of the Araliaceae family is taken with ivy; for example scheffler, a common house plant, and ginseng (Ozdemir et al. 2003). These plants also contain the powerful irritant and sensitizer falcarinol. Finally, ivy berries should be avoided as they are considered poisonous if eaten because they contain certain chemicals known as oxalates, which can cause allergic symptoms of the eyes and skin.

Final words

Ivy is not only decorative plant. Pre-clinical and clinical studies on ivy leaf show its effectiveness as a herbal medicine, particularly for treating respiratory disorders, while for other uses the evidence is very limited. Ivy leaves have been used in ancient and modern times for many disorders, but there is limited clinical evidence supporting its use for diseases other than respiratory bronchial conditions. The future of ivy may lie in further investigation of its other ethnopharmacological uses. Thus, it could be another example of ethnopharmacology-based drug development, an ongoing frontier in drug therapy.

Disclaimer

In this essay we do not to advise or recommend herbs for medicinal or health use. This information is intended for educational purposes only and should not be considered as a recommendation or an endorsement of any particular medical or health treatment. The use of any such product should be based on the appropriate advice of a health care professional or based on the information available in the patient information leaflets (i.e. for THR products)

© Fatimah Qassadi 2020. All rights reserved

I am a pharmacist working in academia who is interested in the field of medicinal plants and natural products and their biological implications for medical and health purposes. I am currently a master’s student of Medicinal Natural Products and Phytochemistry at the School of Pharmacy, University College London (UCL).

Literature cited
Bedir E, Kirmizipekmez H, Sticher O, Calis I. (2000) Triterpene saponins from the fruits of Hedera Helix. Phytochemistry 53: 905-9.

Bolbot Y, Prokhorf E, Mokia S, Yurteseva A. (2004) Comparing the efficacy and safety of high-concentrate (5-7.5:1) ivy leaves extract and acetylcysteine for treatment of children with acute bronchitis. Drugs of Ukrain 11: 1-4.

Bossard C, Randall JM, Hoshovsky I. (2000) Invasive plants of California’s wildlands. University of California Press, 277-281.

Boyle J, Harman RM. (1985) Contact dermatitis to Hedera Helix (Common Ivy). Contact Dermatitis 12: 111-2.

Brussell DE. (2004) Medicinal plants of Mt. Pelion, Greece. Economic Botany 58.

Bunk K, Krassovitski S, Speck T, Masselter T. (2019) Branching morphology and biomechanics of Ivy (Hedera Helix) stem-branch attachments. American Journal of Botany 106: 1143-1155.

Chichiricco G, Cifani MP, Frizzi G, Tammaro F. (1980) Phytotherapy in the Subequana Valley, Abruzzo, Central Italy. Journal Of Ethno-Pharmacology 2.

Cioaca C, Margineanu C, Cucu V. (1978) The saponins of Hedera Helix with antibacterial activity. Pharmazie 33: 609-10.

Cwientzek U, Ottillinger B, Arenberger P. (2011) Acute bronchitis therapy with ivy leaves extracts in a two-arm study. A double-blind, randomised study vs. an other ivy leaves extract. Phytomedicine 18: 1105-9.

Fazio S, Pouso J, Dolinsky D, Fernandez A, Hernandez M, Clavier G, Hecker M. (2009) Tolerance, safety and efficacy of Hedera Helix extract in inflammatory bronchial diseases under clinical practice conditions: A prospective, open, multicentre postmarketing study of 9657 patients. Phytomedicine 16: 17-24.

Gepdiremen A, Mshvildadze V, Suleyman H, Elias R. (2005) Acute anti-inflammatory activity of four saponins isolated from ivy: Alpha-Hederin, Hederasaponin-C, Hederacolchiside-E and Hederacolchiside-F in carrageenan-induced rat paw edema. Phytomedicine 12: 440-4.

Gul R, Jan SU, Ahmed M, Akhtar M, Qureshi MM. (2019) Formulation, characterization and in vivo evaluation of Hedera Helix L., topical dosage forms. Pakistan Journal of Pharmaceutical Sciences 32: 2605-2610.

Guo R, Pittler, MH, Ernst E. (2006) Herbal medicines for the treatment of Copd: A systematic review. European Respiratory Journal 28: 330-8.

Hausen BM, Brohan J, Konig WA, Faasch H, Hahn H, Bruhn G. (1987) Allergic and irritant contact dermatitis from falcarinol and didehydrofalcarinol in common ivy (Hedera Helix L.). Contact Dermatitis 17: 1-9.

Holzinger F, Chenot JF. (2011) Systematic review of clinical trials assessing the effectiveness of Ivy Leaf (Hedera Helix) for acute upper respiratory tract infections. Evidence-Based Complementary and Alternative Medicine 2011: 382789.

Jones JM, White IR, White JM, Mcfadden JP. (2009) Allergic contact dermatitis to English Ivy (Hedera Helix)-A case series. Contact Dermatitis 60: 179-80.

Jors E. (2003) The prevalence of skin and mucosal symptoms in Gardeners Handling Ficus Benjamina (Weeping Fig) and Hedera Helix (Ivy). A cross-sectional study. Ugeskrift for Laeger 165: 3526-9.
Kemmerich B, Eberhardt R, Stammer H. (2006) Efficacy and tolerability of a fluid extract combination of thyme herb and ivy leaves and matched placebo in adults suffering from acute bronchitis with productive cough. A prospective, double-blind, placebo-controlled clinical trial. Drug Research 56: 652-60.

Kim HP, Lim H, Kwon YS. (2017) Therapeutic potential of medicinal plants and their constituents on lung inflammatory disorders. Biomolecules & Therapeutics (Seoul) 25: 91-104.

Kultur S. (2007) Medicinal plants used in Kirklareli Province (Turkey). Journal of Ethnopharmacology 111: 341-64.

Lutsenko Y, Bylka W, Matlawska I, Darmohray R. (2012) Hedera Helix as a medicinal plant. Herba Polinica Journal 56: 83-96.

Maduse G. (1938) Hederea Helix. Lehrbuch Der Biologischen Heilmittel G. Thieme Verlag, Leipzig 1512-1517.

Mahran GH, Hilal SH, El-Alfy TS. (1975) The isolation and characterisation of Emetine Alkaloid from Hedera Helix. Planta Medica 27: 127-32.

Melzer B, Seidel R, Steinbrecher T, Speck T. (2012) Structure, attachment properties, and ecological importance of the attachment system of English Ivy (Hedera Helix). Journal of Experimental Botany 63: 191-201.

Metcalfe DJ. (2005) Biological flora of the British Isles No. 268 Hedera Helix L. Journal of Ecology 93: 632–648.

Meyer-Wegener J, Liebscher K, Hettich M, Kastner HG. (1993) Efeu Versus Ambroxol Bei Chronischer Bronchitis. Zeitschrift für Allgemeinmedizin 69: 61-66.

Ozdemir C, Schneider LA, Hinrichs R, Staib G, Weber L, Weiss JM, Scharffetter-Kochanek K. (2003) Allergic contact dermatitis to Common Ivy (Hedera Helix L.). Der Hautarzt 54: 966-9.

Parvu M, Vlase L, Parvu AE, Rosca-Casian O, Gheldiu A-M, Parvu O. (2015) Phenolic compounds and antifungal activity of Hedera Helix L. (Ivy) flowers and fruits. Notulae Botanicae Horti Agrobotanici Cluj-Napoca 43: 53-58.

Patch D. (2004) Ivy – Boon or Bane? [Online]. The Tree Advice Trust. Available: Trees.Org.Uk. [Accessed 9 April 2020].

Paulsen E, Christensen LP, Andersen KE. (2010) Dermatitis from Common Ivy (Hedera Helix L. Subsp. Helix) in Europe: Past, present, and future. Contact Dermatitis 62: 201-9.

Quiver (1864) Holly and Ivy. British Periodicals 12: 267.

Rai A. (2013) The antiinflammatory and antiarthritic properties of ethanol extract of Hedera Helix. Indian Journal of Pharmaceutical Sciences 75: 99-102.

Rosas-Alvarado A, Morfin-Maciel B. (2013) Cutaneous reactivity to Common Ivy (Hedera Helix) pollen extract in allergic patients. Revista Alergia Mexico 60: 105-9.

Rosca-Casian O, Mircea C, Vlase L, Gheldiu, AM, Teuca DT, Parvu M. (2017) Chemical composition and antifungal activity of Hedera Helix Leaf ethanolic axtract. Acta Biologica Hungarica 68: 196-207.

Schmidt M, Thomsen M, Schmidt U. (2012) Suitability of ivy extract for the treatment of paediatric cough. Phytotherapy Research 26: 1942-7.

Scott TL. (2010) Invasive plant medicine: The ecological benefits and healing abilities of invasives. Rochester, Vt., Healing Arts Press.

Seibel J, Pergola C, Werz O, Kryshen K, Wosikowski K, Lehner MD, Haunschild J. (2015) Bronchipret(R) syrup containing thyme and ivy extracts suppresses bronchoalveolar inflammation and goblet cell hyperplasia in experimental bronchoalveolitis. Phytomedicine 22: 1172-7.

Sieben A, Prenner L, Sorkalla T, Wolf A, Jakobs D, Runkel F, Haberlein H. (2009) Alpha-Hederin, but not Hederacoside C and Hederagenin from Hedera Helix, affects the binding behavior, dynamics, and regulation of Beta 2-Adrenergic receptors. Biochemistry 48: 3477-82.

Smith W, Wayte W, Marindin GE. (1890) A dictionary of Greek and Roman antiquities. London, J. Murray.

Song KJ, Shin YJ, Lee KR, Lee EJ, Suh YS, Kim KS. (2015) Expectorant and antitussive effect of Hedera Helix and Rhizoma Coptidis extracts mixture. Yonsei Medical Journal 56: 819-24.

Stauss-Grabo M, Atiye S, Warnke A, Wedemeyer RS, Donath F, Blume HH. (2011) Observational study on the tolerability and safety of film-coated tablets containing Ivy Extract (Prospan(R) Cough Tablets) in the treatment of colds accompanied by coughing. Phytomedicine 18: 433-6.

Steinmetz E. (1961) Hederae Helicis Folia. Pharmaceutical Biology
3: 93-95.

Suleyman H, Mshvildadze V, Gepdiremen A, Elias R. (2003) Acute and chronic antiinflammatory profile of the Ivy plant, Hedera Helix, in rats. Phytomedicine 10: 370-4.

Theoi. (2000a) Dionysus – Greek god of wine & festivity [Online]. Theoi Project. Available: Https://Www.Theoi.Com/Olympios/Dionysos.Html [Accessed 26 March 2020].

Theoi. (2000b) Dionysus myths 8 favour – Greek Mythology. [Online]. Theoi Project. Available: Https://Www.Theoi.Com/Olympios/Dionysosfavour.Html#Ikarios [Accessed 26 March 2020].

Trute A, Gross J, Mutschler E, Nahrstedt A. (1997) In vitro antispasmodic compounds of the dry extract obtained from Hedera Helix. Planta Medica 63: 125-9.

Trute A, Nahrstedt A. (1997) Identification and quantitative analysis of phenolic compounds from the dry extract of Hedera Helix. Planta Medica 63: 177-9.

Timon-David P, Julien J, Gasquet M, Balansard G, Bernard P. (1980) Search for antifungal activity of several active principles. Extracts from climbing ivy: Hedera helix L. Annales pharmaceutiques françaises 38: 545–552.

Wagner U. (2009) Phytotherapy Research. A Thyme-Ivy combination using synergy effects in action. Pharm Unserer Zeit 38: 83-5.

William KW. (1965) The portraits of Alexander Pope. Yale University Press, New Haven 6.2-6.6, 52,54-57.

Yu M, Liu J, Li L, Xu H, Xing Y, Zhao Y, Yu Z. (2016) Pharmacokinetic parameters of three active ingredients Hederacoside C, Hederacoside D, and A-Hederin in Hedera Helix in rats. Journal of Separation Science 39: 3292-301.