Believed to have originated in Egypt, this plant has almost world wide distribution. There are numerous varieties of this species, each one varying primarily in flower shape and color. Calendula grows to about two feet in height and the wild form has small, bright yellow-orange flowers that bloom from May to October. It is the ligulate florets, mistakenly called the flower petals, that have been used medicinally. This plant should not be confused with several other members of the family that also carry the "marigold" name.
The plant has been grown in European gar?dens since the 12th century and its folkloric uses are almost as old. Tinctures and extracts of the florets had been used topically to promote wound healing and to reduce inflammation; systemically, they have been used to reduce fever, to control dysmenorrhea and to treat cancer. The dried petals have been used like saffron as a seasoning and have been used to adulterate saffron. The pungent odor of the marigold has been used as an effective pesticide. Marigolds are often interspersed among vegetable plants to repel insects.
A number of studies have been reported describing the chemistry of calendula. Almost all of the investigations regarding this plant have been conducted in Eastern Europe. The plant contains a number of oleanolic acid glycosides. Flavonol-2-Q-glycosides have been recovered from C. officinalis via high pressure chromatography. Calendulin (also known as bassorin) has been identified in the plant.1 Sterols and fatty acids, such as calendic acid, are present in the plant.6-8 In addition, the plant contains triterpenoids,9 tocopherols, 1 0 mucilage and a volatile oil. The carotenoid pigments have been used as coloring agents in cosmetics and the volatile oil has been used in perfumes.
Despite the history of use of calen?dula and the rather detailed studies of its chemistry, there are almost no studies regarding its efficacy in the treat?ment of human disorders. Calendula extracts have been used topically to promote wound healing, and experiments in rats have shown that this effect is measurable. An ointment containing 5% flower extract in combination with allantoin was found to "markedly stimulate" epithelialization in surgically?induced wounds. On the basis of histological examination of the wound tissue, the authors concluded that the ointment increased glycoprotein, nucleoprotein and colla?gen metabolism at the site.
Russian investigators found that sterile preparations of calendula extracts alleviated signs of chronic conjunctivitis and other chronic ocular inflammatory conditions in rats the extracts also had a systemic anti-inflammatory effect. Other Russian investigators have used plant extract mixtures containing calendula for the treatment of chronic hyposecretory gastritis. Extracts of the florets are uterotonic in the isolated rabbit and guinea pig uterus.
Calendula extracts have in vitro antibacterial, antiviral and immunostimulating properties. Published reports of small clinical trials conducted in Poland and Bulgaria suggest that extracts of the plant may be useful in the management of duodenal ulcers, gastroduodenitis. and periodontopathies.
Despite its widespread use, there have been no reports in the Western literature describing serious reactions to the use of calendula preparations. A report of anaphylactic shock in a patient who gargled with a calendula infusion has been reported in Russia.
Allergies to members of the family Compositae (cha.momile, feverfew, dandelion) have been reported, in particular to the pollens of these plants. Users of calendula preparations should consider the potential for allergic reactions to occur.
In animals, doses of up to 50 mg/kg of extract had essentially no pharmacologic effect and induced no his topathologic changes following either acute or chronic administration. Saponin extracts of C. officinalis have not been found to be mutagenic.
Calendula is one of the many plants used persistently despite no clear evidence that its compo?nents exert any consistent pharmacologic effect. Some support in the form of animal studies exists for its topical wound healing and anti-inflammatory uses, and these properties should be investigated further.the plant appers to have a low potential for toxicity,but nevertheless,cannot be recommended at this time for the systemic treatment of any disease.
Candula has been uses in folk medicine topically to treat wounds and internaly to reduce fever,treat cancer nad control dysmenorrhea.Extracts have proved antibacterial,antiviral and immunostimulation in vitro.Petals are consumed as a seasoning. The plant has been used to repel insects.
Allergic reactions to the botanical family and on ecase of anaphylaxis has been reported.