Lonicera japonica Thunb.

Botanical Name

Lonicera japonica Thunb.

Synonyms

Caprifolium chinense S.Watson ex Loudon, Caprifolium japonicum (Thunb.) Dum.Cours., Caprifolium roseum Lam., Lonicera brachypoda Siebold, Lonicera fauriei H. Lév. & Vaniot, Lonicera shintenensis Hayata [4]

Family

Caprifoliaceae

Vernacular Names

English Chinese honeysuckle, Japanese honeysuckle [1]
China Jin yin hua (flowers); ren dong teng (stems with leaves attached); [6] jen-tung [5]
Vietnam Kim ngam, day nhan dong [5]
Tibet 'Phan nag [7]

Description    

Lonicera japonica is a member of the Caprifoliaceae family. It is a climbing shrub with tomentose young leaves and stems. The leaves are simple, opposite and without stipules. The leaves blade is elliptic, 3-8 cm x 2-3 cm with base obtuse. The flowers form at the leaf axils,  white and  turning yellow upon maturity. The fruits are globose and black [3].

Distribution

They are native of East Asia but is widely cultivated and naturalised throughout the world [3].

Plant Use

The plant is used mainly as an ornamental in most countries especially for the fragrance of its flowers. It is also considered medicinal in China and Japan where it is prescribed for fever, pneumonia, dieresis, dysentery and skin infections like furuncles [1] [3].

Toxic Parts

Buds and flowers [1].

Toxin

The buds and flowers of L. japonica contain saponin (lupine-triterpene, glycosides, iridoid glycosides, loniceroside C), flavones and phenolic compounds. The herbal preparations where the flowers form a component have the following compounds: chlorogenic acid, caffeic acid, loganin, sweroside, secoxyloganin, rutin and luteolin 7-O-glucoside.

It also contains carotenoid tetraterpenoids such as webbiaxanthin and loniceraxanthin, and triterpenoid saponins lonicerarosides A, B and C. These compounds have the potential to irritate the mucosa of the digestive tract, though it is not confirmed.  Some of the phenolic compound (methyl caffeate,3,.4-di-O-caffeolquinic acid, methyl 3,4-di-O-caffeolquinic acid and 3,4-d-O-caffeolyquinate) inhibit ADP-induced platelet aggregation in vitro [1] [2].

Risk Management

The risk of poisoning of this plant is minimal and the adverse effects had been isolated. The plant would be safe to grow even with the presence of toddlers. They are not attractive enough to command the attention of those curious individuals [1] [2] [3].

Clinical Findings

Contact with the sap had resulted in pruritic, maculopapular rash. There has been report of development of mydriasis, myalgias and mild gastrointestinal irritation manifested as nausea, vomiting and diarrhoea in people consuming the berries. [1]

Management

Treatment is usually supportive and is directed towards prevention of absorption of toxicant by giving activated charcoal and then towards relief of any persistent vomiting [2].

Topical steroids and antihistamines would provide sufficient relief of contact dermatitis as a result of contact with L. japonica [1].

References

  1. Barceloux DG. Medical toxicology of natural substances: Foods, fungi, medicinal herbs, plants and venomous animals. Hoboken, New Jersey: John Wiley & Sons; 2008. p. 863-864.
  2. Burrows GE, Tyrl RJ. Toxic plants of North America. Ames, Iowa: John Wiley & Sons; 2013 p. 320-321.
  3. Koh HL. A guide to medicinal plants: An illustrated scientific and medicinal approach. Singapore: World Scientific Publications; 2009. p. 89-91.
  4. The Plant List. Ver 1.1. Lonicera japonica Thunb.  [homepage on the Internet]. c2013. [updated 2012 Apr 18; cited 2014 Sept 29] Available from: http://www.theplantlist.org/tpl1.1/record/kew-2339716 
  5. Wiart C. Ethnopharmacology of Medicinal Plants: Asia and the Pacific. New Jersey: Humana Press; 2006. p. 10. 
  6. Foster S, Chongxi Y. Herbal emissaries: Bringing Chinese herbs to the West: A Guide to Gardening, Herbal Wisdom, and Well-Being. Vermont: Inner Traditions/Bear; 1992. p. 292
  7. Arya PY, Compiler. Gyatso Y, editors. Dictionary of Tibetan materia medica. Delhi: Motilal Banarsidass Publishers; 1998. p. 143.