

Gold-bloom, Marigold, Marybud, Pot Marigold
Extracted from the flower of the marigold plant, calendula is used topically for wound healing (1). Major constituents of the leaves and stems of the plant include lutein and beta-carotene (2). Extracts from calendula demonstrated anti-inflammatory properties (3), which may improve wound healing (4), and antibacterial, antiparasitic (5), anti-HIV (6), cytotoxic and anti-tumor effects (9) (10) both in vitro and in vivo. Further, studies done in mice indicate hepato- and renoprotective effects (14).
An herbal formulation containing calendula was found effective in reducing earache in children with acute otitis media (7) (8). Preliminary data support use of topical calendula for prophylaxis of acute dermatitis during radiation therapy in cancer patients (11) (13). More research is needed.
Calendula is known to cause allergic reactions (1) (12).
Triterpenoids from Calendula have been shown to have anti-inflammatory (3) (6) and anti-HIV activities (2). The most active triterpenoid is a monoester of faradiol (1). The organic extract of calendula has been shown to suppress cell fusion which may inhibit early events in the HIV replication cycle (6). Extracts from calendula were shown to be cytotoxic and exhibit antitumor activity in mouse Ehrlich carcinoma model, although the effects were not always consistent (9).
Calendula should be avoided during pregnancy and lactation (1).
Pommier P, et al. Phase III Randomized Trial of Calendula Officinalis Compared With Trolamine for the Prevention of Acute Dermatitis During Irradiation for Breast Cancer. J Clin Oncol 2004;22:1447-53. Two hundred fifty-four patients who underwent surgery for breast cancer were randomized to receive either Calendula or trolamine, a routine treatment for topical application during postoperative radiation therapy. Occurrence of grade 2 or higher acute dermatitis was significantly lower in patients who used Calendula compared to those who used trolamine.
Due to differences in texture, color, and smell, the trial was single-blinded. Double-blinded studies are needed to confirm the beneficial effects of calendula.
Bottom Line: Topical application of calendula may reduce painful swelling and irritation associated with radiation therapy. It has not been shown to treat cancer.
Naturally occurring chemicals derived from the marigold plant have been shown to reduce inflammation in laboratory studies. These chemicals, which are called triterpenoids, also inhibit HIV virus and some tumors. When applied to the skin, extracts of Calendula help to heal wounds and inflammation after radiation therapy.
Radiation Therapy Associated Dermatitis:
Two hundred fifty-four breast cancer patients undergoing radiation therapy participated in a trial of Calendula to see if it would reduce skin inflammation due to radiation therapy. The patients were randomly assigned to receive a topical ointment containing either Calendula or trolamine. Trolamine is an accepted treatment for skin inflammation. Subjects who used Calendula had fewer cases of severe skin inflammation. Because the texture, color, and smell of the two ointments were quite different, patients knew which treatment they were receiving. Researchers did not know which treatment they had received. This study suggests of Calendula ointment may be used as a preventative treatment for skin inflammation due to radiation therapy.