Calendula
Calendula officinalis

Location
Wildflower plot.

Description
Also known as pot marigold. Calendula is an annual, native to southern Europe, and grows well in direct sun (Grieve 1998).

History
Calendula was historically used extensively in food preparation to give cheeses and butters a golden-yellow hue (Foster 2006). The dried and fresh petals continue to be used as a more cost-effective alternative to saffron to give flavor and color to soups, chowders, seafood, and meat (Duke 1985). Calendula has a long history of use due to the belief in its antibacterial, antiviral and immune-stimulating properties (Duke 1997). In folk medicine, preparations of the whole plant or calendula flowers mixed with milk were said to be a cancer treatment (Duke 1985). Tinctures of calendula have been touted as remedies to aid wound healing, bruising, cramps, chronic ulcers, and varicose veins. Calendula tea was recommended for sore eyes, and the blossoms were rubbed on bee stings to reduce pain and inflammation (Duke 1985).

Current medicinal uses
Calendula flowers are still popular as a topical antiseptic and anti-inflammatory to treat burns, skin sores, or irritated skin. In one randomized controlled trial, 254 postoperative breast cancer patients applied either trolamine (a standard treatment) or calendula topically after receiving radiation therapy. Those who used calendula had significantly reduced incidence of acute dermatitis above grade 2 (Pommier 2004). The naturopathic formula Otikon, which contains calendula flowers, was found to be as effective in treating ear pain associated with otitis media as anesthetic ear drops in a study of 103 children (Sarrell 2001). A second study found that another naturopathic ear drop formulation resulted in greater pain relief on days two and three of infection than antibiotic drops (Sarrell 2003). However, anesthetic drops alone were also superior to antibiotic treatment, which points to a lack of benefit with antibiotic treatment rather than a benefit for naturopathic ear drops.

Adverse effects
Topical calendula is considered safe because of its long history of human use. A risk assessment of components found it to be benign (Re 2009). However, current data are insufficient to support the use of Calendula officinalis extract in the nearly 200 cosmetic products in which it appears (Cosmetic Ingredient Review Expert Panel 2001). People sensitive to other members of the Asteraceae family could have allergic reactions to calendula.

References
Cosmetic Ingredient Review Expert Panel. Final report on the safety assessment of Calendula officinalis extract and Calendula officinalis. International Journal of Toxicology. 2001; 20(2): 79-84.

Duke JA. Handbook of Medicinal Herbs. CRC Press: Boca Raton, FL, 1985. (p. 87-88).

Duke JA. The Green Pharmacy. St. Martin’s Press, 1997. (p. 439)

Foster S and Johnson R. Desk Reference to Nature’s Medicine. National Geographic: Washington, DC, 2006. (p. 34-35).

Grieve M. A Modern Herbal. Tiger Books International, London, 1998 (first published in 1931 by Jonathan Cape Ltd).

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. Journal of Clinical Oncology. 2004; 22(8): 1447-1453.

Re TA et al. Application of the threshold of toxicological concern approach for the safety evaluation of calendula flower (Calendula officinalis) petals and extracts used in cosmetic and personal care products. Food and Chemical Toxicology. 2009; 47: 1246–1254.

Sarrell E et al. Efficacy of naturopathic extracts in the management of ear pain associated with acute otitis media. Arch Pediatr Adolesc Med. 2001; 155(7): 796-9.

Sarrell E et al. Naturopathic treatment for ear pain in children. Pediatrics. 2003; 111(5 Pt 1): e574-9.