Introduction     ▲

The plant called Marigold is an annual plant, of which there are many varieties, presenting flowers ranging from bright yellow to orange. Marigolds belong to the family Asteraceae, which includes several dozen species, some of which are edible (petals and young leaves).

Its name comes from the calendas, the Latin name given to the first day of the month, by the widespread belief that the flowering of the plant had a monthly rate. In the wild they can reach a height of 50 cm. Today, marigold grows only in places of culture, though not exceptional find silvester plants outside these spaces.

Marigold is native to Egypt. The flowering of the cultivated plant covers practically all the year. Of the plant are harvested flower heads.

One issue to keep in mind with all medicinal plants

An observation about a case of severe hepatitis due to the use of material from Greater Celandine reminds us that plant-derived products may involve more risk than people believe. The widespread use of plants for food has reinforced the idea that eating plants promotes health.

With the development of organic chemistry in the nineteenth century has been possible for the first time purify and identify the substances pharmacologically active from plants and subsequently synthesize similar compounds with a more powerful action.

Activity, safety and composition of these substances can be controlled in the same way as purely synthetic substances. However, there are people who believe that traditional plants are better and safer than modern pharmaceuticals. Both qualitative and quantitative composition of these plant derivatives are obtained from what we call alternative medicine that escapes the scope of the legislation established to protect the health of citizens and ensure the effectiveness and safety of the products that are addressed to treat diseases (excerpted from J. van Noordwijk. Ned Tijdschr Geneeskd. 2002 Jan 19, 146 (3) :100-2.).

Composition     ▲

In flower heads there is an essential oil, which contains carotenoids (carotene and lycopene), a resin, a saponin and a bitter principle (calenduline).

The dichloromethane extract of dried marigold flowers contains eight triterpendiol monoesters: faradiol-3-O-palmitate, faradiol-3-O-myristate, faradiol-3-O-laurate, arnidiol-3-O-palmitate, arnidiol-3-O-myristate-3-O arnidiol laurate, calenduladiol-3-O-palmitate and calenduladiol-3-O-myristate. Were also isolated several flavonol 3-O-glycosides.The main components of the lipophilic extract of marigold flowers, triterpendiol esters are particularly faradiol laurate, faradiol myristate and faradiol palmitate.

Nineteen carotenoids have been identified in extracts of marigold petals, some of which are exclusive to orange flowers. The main carotenoids in the petals and pollen are flavoxanthin and auroxanthin, while the leaves and stems contain mostly lutein and beta-carotene.

Traditional applications     ▲

Popularly is attributed to this plant the property of promoting wound healing. It is also considered that it is choleretic and emmenagogue.

Marigolds were traditionally used for irritations, eczema, ulcers and wounds as a poultice or ointment. Other forms of preparation such as tincture or extract have also been used frequently.

Other applications include marigold therapeutic use in relieving local pain, various skin conditions and as an antiinflammatory, analgesic, antiseptic and antibacterial remedy.

Besides its use in people, marigolds have been used since time immemorial in popular veterinary to treat diarrhea in livestock and pets.

Experimental studies     ▲

Studies, mostly preliminary, made ??in laboratory animals or in the test tube (in vitro) have identified the following properties in the Calendula officinalis

1.Suppression of inflammatory effect and leucocyte infiltration.

2. Significant improvement of experimental burn compared to untreated controls.

3. Meaningful antioxidant activity, which could be used in various inflammatory or allergic diseases.

4. Protective effect on atopic dermatitis.

5. The Calendula officinalis has an immunomodulatory effect against three non-pathogenic virus for humans.

6. One study found that the plant could have a stimulating effect on physiological regeneration and repair of tissues, perhaps by an increased metabolism of nucleoproteins and glycoproteins during the regenerative phase of tissues.

7. Was determined the capacity of marigold extract to stimulate lymphocyte proliferation.

8. Two triterpene glycosides from marigold show cytotoxic effects in vitro against cells derived from colon cancer, leukemia and malignant melanoma.

9. The principal members of saponins, glycosides A, B, C, D, and F, exhibit a potent inhibitory effect on glucose levels in laboratory animals.

10. It appears that the marigold flower extract contains components with spasmolytic and spasmogenic effects.

11. In an experimental animal model, marigold extracts appear to accelerate the healing of gastric ulcers.

12. Marigold extract has a toxicity and genotoxicity dose-dependent against aspergillus.

13. The antiinflammatory activity of marigold extracts is proportional to their content of monoester faradiol. In turn, faradiol is more active than its esters. It has also been proven an antiedematous effect of faradiol esters in a dose dependent manner. it was, according to the study, comparable to indomethacin.

14. Also was detected a reduction of the effect of reverse transcriptase activity of HIV-1. In an acellular enzymatic system, was achieved the reduction of reverse transcriptase activity by 85%, after a 30 minute treatment with the organic extract of marigold, suggesting a possible therapeutic property against infection by HIV.

Toxicity     ▲

Toxicology studies in laboratory rats and mice suggest that the marigold extract is relatively slightly toxic. However, the available data are insufficient to support the safe use of medical and cosmetic components containing marigold.

Laboratory animals showed a minimal skin or eye irritation, devoid of photosensitivity or phototoxicity. Also in laboratory tests in experimental animals it was found an elevation of BUN and ALT as well as evidence of renal and hepatic overload.

Clinical studies     ▲

There are published observations of clinical applications of marigold in different processes. Most of the works are not conclusive and do not support the therapeutic application of the preparations of this plant. In general, the studies have methodological flaws that do not allow generalization of the findings.

The plant has been tested in periodontitis, in combination, with apparent good results. It has been found in preliminary trials a significant difference in wound healing. The authors suggest possible application in the treatment of venous ulcers.

One observation, comparing the effect of aciclovir alone versus combined with marigold and two other plants in 52 patients with herpetic keratitis, concludes that combination therapy produces a greater reduction of nuisances and the time resolution of the ulcerations that acyclovir alone.

A clinical article concluded that Calendula is highly effective in preventing acute dermatitis grade 2 or higher and should be given in patients receiving radiotherapy for breast cancer.

Another study found a beneficial effect of marigold extract on the discomfort caused by acute otitis media in children from null effect of antibiotic treatment.

Twenty-four patients with non-specific colitis were treated with a combination of herbs including marigold. The discomfort disappeared in all but one after fifteen days of treatment. The study did not include a control group.

Adverse reactions     ▲

It have been described atopic dermatitis due to extracts of various plants including calendula, without being able to isolate a single plant causal.

It is considered that the family of the compounds is a frequent source of contact allergy. It have ben described a case of anaphylactic shock after gargling with an infusion of marigold.

Date page update: December 15, 2008.