Volume 34, Issue 10, Page 17 (October 2003)

Popularly known as pot marigold or garden marigold, Calendula officinalisis a bright, flowering herb native to Asia, Central and Southern Europe, and the Mediterranean region.

Like many other members of the Compositae, or Asteraceae, family—which include daisies, arnica, chamomile, and yarrow—calendula is now cultivated throughout the world and is valued for its culinary and medicinal uses.

It has long been considered a soothing herb that, more recently, has been found to possess antibacterial, anti-inflammatory, and antioxidant properties.

In ancient Rome, calendula was used for breaking fevers. In medieval Europe, it was grown in monastery gardens and used as a vulnerary. During the American Civil War in the 1860s, calendula was used as an antiseptic to clean and treat battle wounds and prevent gangrene. Today, calendula remains a popular antiseptic component in the armamentarium for wound care.

From Eczema to Acne

Naturopathic healers also recommend calendula for treating eczema, and they note that the nontoxic herb acts topically as an anti-inflammatory and systemically to promote blood clotting. Topically applied calendula formulations have been shown effective in treating diaper rash and nipples that are tender and sore from breast-feeding. Nearly 200 cosmetic formulations representing a wide range of product types are believed to contain C. officinalis extract (Int. J. Toxicol. 20[suppl. 2]:13-20, 2001).

Naturopathic healers attribute antispasmodic, antimicrobial, and antiviral activity to calendula. They recommend calendula systemically, for digestive problems, and topically, as an external wash, for ocular inflammations, abscesses, acne, bee stings, boils, eczema, and varicose veins. Calendula also is used in a gargle for oral problems such as sores and toothaches. In various forms, calendula extracts are believed to be useful in wart removal, as a vaginal douche, and as a topical hemorrhoid treatment.

Among homeopathic practitioners, calendula is considered a suitable home remedy for treating scrapes and burns (Prof. Care Mother Child 4[7]:212-13, 1994). Western medicine has also incorporated the use of calendula as an antiseptic and anti-inflammatory agent, treating certain skin disorders and pain (Redox Rep. 7[2]:95-102, 2002).

Like the expansive range of calendula products, the number of potential indications is wide and growing. Anti-HIV characteristics have been found in organic C. officinalis extract, which has prompted research into possible therapeutic applications (Biomed. Pharmacother. 51[4]:176-80, 1997).

Anti-Inflammatory Action

The mechanism of action is not fully understood, but the key constituents in calendula are likely saponins, carotenoids, essential oil, sterols, flavonoids, and mucilage.

Triterpenoids appear to be the most significant anti-inflammatory components of the flower (Planta Med. 60[6]:516-20, 1994). Further, an increasing number of scientific studies support the anti-inflammatory activity of calendula. A study in mice showed significant anti-inflammatory evidence in several members of the Compositae family, including calendula (Phytochemistry 43[6]:1255-60, 1996). The sesquiterpene lactones appear to be the components most responsible for eliciting allergic reactions (Contact Dermatitis 47[4]:189-98, 2002).

Research has shown that the butanolic fraction of C. officinalis displays antioxidant, free radical-scavenging activity (Redox Rep. 7[2]:95-102, 2002). The concentrations of flavonoids and carotenoids in calendula are sufficiently high that calendula flowers have been used as natural orange-yellow dyes.

Such components are quite possibly responsible for yielding the reputed antioxidant effect. In fact, calendula flowers contain the potent antioxidant carotenoids ?-carotene, lutein, and lycopene. This sheds some light on the potential reasons that anti-inflammatory, antiseptic, antihemorrhagic, antiulcerogenic, and immunostimulating characteristics have been attributed to calendula. And recent research continues to bear out the viability of producing formulations with biologic activity using the extracts of C. officinalis (Toxicol. In Vitro 16[3]:253-58, 2002).

There is evidence that calendula and other members of the Compositae family may have allergenic potential, though.

In a test of 443 consecutive patients in Austria, researchers determined that Compositae allergy is a significant contributor to the incidence of contact dermatitis (Contact Dermatitis 45[5]:269-72, 2001).

Some researchers believe that the increasing use of herbal medicine and herb-based cosmetics may lead to an increase in contact dermatitis, because some of the more popular herbs—arnica, chamomile, marigold, and Echinacea—are members of the Compositae family.

The relative risks of provoking contact dermatitis from the use of products containing herbs of the Compositae family are not yet known (Contact Dermatitis 47[4]:189-98, 2002). In addition, despite a growing body of research on the use of calendula, current data are not sufficient to establish a scientific standard of safety for C. officinalis extract in cosmetic formulations (Int. J. Toxicol. 20 [suppl. 2]:13-20, 2001).

Marketing Calendula

Various products on the market tout the soothing qualities of calendula. AFE Cosmetics & Skincare markets Calendula Moisturizer, Ultimate Line ($45/4-oz tube; $15/1-oz tube), containing C. officinalis extract, propylene glycol, vitamins C and E, and other herbal extracts such as horsetail and rosemary. Credentials markets Calendula Crème ($22/2-oz jar), a lightweight preparation intended to “protect the skin from environmental pollutants” made with calendula; vitamins A, C, and E; and five other herbal extracts.

Nerys Purchon's Skincare (Australia) employs calendula for its reputed valuable healing qualities. Their Calendula Salve ($8/20g) is a triple-infused formula that the manufacturer states is suitable for burns, cuts, or lacerations and may help facilitate healing with minimal scarring and without causing infection. Also containing an infusion of calendula along with several vitamins, Nusha Virtual Skincare Salon's Calendula Oil-Free Creme ($35/2 oz) is a moisturizer intended for oily skin.

Logona Naturkosmetik (Germany) has manufactured a line of topical calendula formulas aimed at daily skin care. Logona Calendula Baby Moisture Cream ($8.95/3.4 oz) is a mild, all-purpose cream containing calendula, jojoba, and almond oil intended to protect delicate baby skin and “maintain a healthy oil/water skin balance.” Other preparations in the line include Calendula Baby Bath ($8.99/6.8 oz), Calendula Baby Diaper Cream ($7.99/3.4 oz), Calendula Baby Body Lotion ($8.95/3.4 oz), and Calendula Baby Bodycare Oil ($8.95/6.8 oz).

Anecdotal Safety

As is the case with several, possibly even most, herbal components, there is a long history of traditional medical use of calendula and compelling anecdotal evidence of its efficacy for certain dermatologic conditions.

As is also the case with most herbs and herbal ingredients in cosmeceuticals, there are few randomized, double-blind, placebo-controlled studies that establish incontrovertible evidence of efficacy. Products containing calendula do appear to be safe, by and large; reports of adverse effects, usually allergic contact dermatitis, are relatively rare. There does seem to be great potential for products of the Compositae family to elicit allergic reactions, though.

Additional research is necessary to assess the relative safety of these products and to determine if such herbal cocktails, with calendula as a leading active ingredient, can confer the same or similar benefits as those reported from traditional use of the less dilute form of the herb.

Dr. Leslie S. Baumann is director of cosmetic dermatology at the University of Miami. To respond to this column, or to suggest topics for future columns, write to Dr. Baumann at our editorial offices via e-mail at sknews@imng.com.

© 2003 International Medical News Group. Published by Elsevier Inc. All rights reserved.