Treatment of rosacea with herbal ingredients

Journal of Drugs in Dermatology, Jan, 2006 by Jessica Wu

Abstract

Since rosacea is a chronic disease and many patients find prescription therapies unsatisfactory, they frequently turn to herbal ingredients for relief of their persistent facial redness. The most useful and frequently used herbal compounds include licorice, feverfew, green tea, oatmeal, lavender, chamomile, tea tree oil, and camphor oil. The utility of most of these herbs is based on their purported anti-inflammatory properties. Some of these herbs have proven effects, many have potential benefits, and some may aggravate rosacea. Due to the fact that many patients fail to inform their physicians about their use of herbal ingredients, dermatologists should be aware of what patients may be using and be able to advise them about the efficacy of these ingredients or the potential for adverse effects.

Introduction

Since the skin of the face is the most common site of involvement, rosacea often has an adverse impact on patient quality of life. In recent surveys by the National Rosacea Society, nearly 70% of rosacea patients indicated that their rosacea decreased their self-confidence and self-esteem, and 41% reported that rosacea had caused them to avoid public contact or cancel social engagements. (1) Among rosacea patients with severe symptoms, nearly 70% said the disorder had adversely affected their professional interactions, and nearly 30% said they had even missed work. (1)

Treatment of rosacea is chronic and the results achieved with pharmacologic therapies are often unsatisfactory. In addition, many patients exhibit sensitivity to topical therapeutic agents and the resulting inflammation may aggravate and accelerate the progression of the disease. Many patients use topical over-the-counter (OTC) agents to treat the symptoms of rosacea, either as an alternative to traditional prescriptions or to complement their prescription regimen. Increasingly, many of these OTC preparations contain herbs. Current estimates report that consumers in the US spend more than 21 billion dollars on alternative medicine and the use of herbal remedies saw an unprecedented 380% increase between 1990 and 1997. (2)

By definition, herbs are botanicals used for medicinal purposes, flavoring, or fragrance. Herbal medicine is based upon the principle that the naturally occurring mixture of active plant compounds is more effective and safer than individual molecules and manufactured combinations of synthetic compounds. (3) Herbal medicine plays several roles in the American medical system by providing alternatives to prescription medications, enhancing the therapeutic effects of other prescriptions and protecting against allopathic side effects, and providing treatments for conditions lacking prescriptive cures or for which there are only high-risk or ineffective therapies.

Quality control in the formulation of herbal preparations poses the challenge of balancing the need for consistency in processing the raw materials while maintaining the potency of the bioactivity of the botanical. The greatest task in producing an effective herbal preparation or herbal cosmeceutical is standardization of the herbal extract as each source plant may contain variability in marker compounds as well as individual components due to variable growing conditions and differences in harvesting procedures that may impact the composition of the herb and the active ingredients. Other issues include appropriate plant identification, genetic variability, adulteration, and batch-to-batch variation.

Herbs Used to Treat Rosacea

Licorice

Licorice plants of the genus Glycyrrhiza have long been used in Chinese medicine for their noted therapeutic effects against a wide range of diseases. The plant was introduced to the Ancient Greeks by the Scythians and has been used since the Middle Ages. Today, several varieties of licorice grow wildly in the lands between southeastern Europe, south-western Asia, and Iraq.

Glycyrrhizin, one of the main ingredients in licorice, is believed to contribute to the herb's many healing properties. Laboratory studies have shown that glycyrrhizin reduces inflammation, promotes mucous secretion, soothes irritation, and stimulates adrenal gland activity. (4) Glycyrrhizin also appears to have antiviral properties, combating hepatitis B, influenza, and HIV by boosting T-cell counts and stimulating production of interferon and other protective compounds. (5) Other ingredients improve stomach ulcers (glycyrrhizinic acid) and soothe inflammation (glabridin and licoicidin).

The genus is diverse, with more than 30 species of Glycyrrhiza. G glabra and G inflata are the two most-studied. Glabridin is the active component of G glabra (Figure 1). A study by Yokota and associates reported that a 0.5% glabridin solution inhibited UVB-induced pigmentation and erythema. (6) The compound's anti-inflammatory properties are due to the inhibition of superoxide anion production and cyclooxygenase activity.

Glycyrrhizinic acid has also been shown to improve dermatitis. In a study by Saeedi and associates, 2% glycyrrhizinic acid gel was reported to significantly decrease scores for erythema, edema, and itching over the 2-week treatment period. (7)