Gardenia jasminoides Ellis (= G. grandiflora Lour.), a native of China and Indochina, is an ornamental and medicinal woody plant. This plant, belonging to the Rubiaceae, is an evergreen small shrub with white, solitary and fragrant flowers. The double-flowered form is usually used for ornamental purposes, while the single-flowered form is used as a medicinal plant, since the former does not bear fruits, a medicinally used organ.
G. jasminoides, as well as its variety, G. jasminoides var. ovalifolia Nakai, is called gardenia and used as a garden tree in Europe and North America, and also as a pot plant in Greece. This plant was once called Cape jasmine in North America because of its fragrant flowers, which were popular for cutting. In China it is called Zhi-zi, and the dried fruits have been medicinally used for curing various inflammatory diseases including hepatitis and cystitis. The dried fruits of G. jasminoides and of its form, G. jasminoides f. grandiflora Makino, are called San-shi-shi in Japan and have been used as a dyestuff and an antiphlogistic, diuretic and haemostatic drug in Chinese traditional medicine. A demand for the fruits as food colouring has been rapidly increasing and currently more than 150 tons of the dried fruits have been imported to Japan every year (Japanese Association for Industrial Crops 1985).
As pharmacologically active principles, several iridoid glucosides have been isolated from the fruits and the leaves of gardenia and their structures have been established. Of these compounds geniposide is contained most abundantly and its content in the dried fruits was reported to be about 4%. Genipin, which is formed from geniposide by hydrolysis in the digestive tracts, has been shown to exhibit laxative and choleretic activities as well as inhibitory effect on gastric acid secretion based on its anti-cholinergic action. The aglucone of gardenoside, one of the iridoid glucosides in gardenia, was shown to have antimicrobial activity against Staphylococcus aureus and Klebsiella pneumoniae ().
Gardenia jasminoides Ellis: Summary
Gardenia is a perennial evergreen shrub of both ornamental and medicinal value. Efficient methods for clonal propagation of this plant through shoot tip culture have been established.
Some of the iridoid glucosides could be produced in the cultured cells in comparable amount to the intact organ. However, formation of geniposide, a major and pharmacologically active iridoid glucoside in the fruits of Gardenia, in the cultured cells has not been investigated in detail. In addition, attempts to induce production of crocin, another main pigmented metabolite of value, in the cultured cells have so far been unsuccessful.
By using the cultured cells of Gardenia, glucosylation of various phenolic compounds has been investigated to understand the regulatory mechanism of conjugation reactions of xenobiotic phenols in plant cells and also to establish large-scale production of useful glucosides by using plant cell culture system.
Selections from the book: “Medicinal and Aromatic Plants II”, 1989.