AHP Releases Quality-Control Standards for Slippery Elm Inner Bark

SCOTTS VALLEY, Calif.The American Herbal Pharmacopoeia® (AHP), a non-profit research organization, released its quality-control standards and therapeutic compendium for the botanical dietary supplement Slippery Elm Inner Bark (Ulmus rubra Muhl). Each monograph establishes national standards for assuring authenticity, purity and quality control of the monographed botanical. Accompanying the standards is the AHP Therapeutic Compendium which provides a complete and critical review of the pharmacological and safety data currently available, including information on pharmacokinetics, pharmacodynamics, actions, medical indications, historical and modern and traditional use, structure and function claims, dosages, interactions, side effects, contraindications, toxicology and more.

The inner bark of slippery elm has a variety of uses, from an ingredient in several popular herbal tea blends (Essiac®, Throat Coat®) to the essential constituent in throat lozenges. Historically, it was praised for its demulcent properties, which were utilized in the treatment of a variety of inflammatory conditions of the digestive, respiratory sand urinary systems and topically for skin diseases and even healing wounds. Though the modern medical research on the inner bark is scarce, the historical information is abundant and is addressed in great detail in the Medical Indications Supported by Traditional Use section.

Deserving special attention is the Swelling Volume Assay described in the Analytical section. The method allows for quantitative assessment of the bark mucilage in contrast to the current qualitative-only method included in the United States Pharmacopeia (USP). The assay proposed by AHP builds on the assay of the European Pharmacopoeia (2.8.4), but is considerably improved by greatly reducing the procedure time. The assay is simple and straightforward, and provides a convenient way for quality control of the material, poor examples of which can often be found in the market.

Slippery elm inner bark is the fourth largest harvested commodity in the U.S. herbal market. However, this valuable resource is being threatened by the spread of Dutch elm disease, which began in the United States in the 1930s with the introduction of European elm bark beetle and since then has undermined elm populations countrywide.

The AHP monograph thoroughly addresses this fact by developing recommendations on best harvest practices of the bark that would ensure the collection does not adversely affect the remaining trees in the population and may even serve as a sanitary measure. The recommendations have been developed in the collaboration with plant pathologists of the United States Department of Agriculture (USDA) Forest Service and can be found in the information box in the Commercial Sources and Handling section.