The fourteenth Laboratory Guidance Document (LGD) from the ABC-AHP-NCNPR Botanical Adulterants Prevention Program (BAPP) focuses on adulteration and substitution of Indian frankincense (Boswellia serrata) with resins from related species.

The Boswellia oleogum resin and extract LGD is also the 74th peer-reviewed publication published by BAPP, an international consortium of organizations with interest in herbs and medicinal plants.

Indian frankincense has been valued for thousands of years for its fragrance and medicinal properties and is commonly called boswellia in the global botanical industry. An oleogum resin is a naturally occurring mixture of resin (a viscous mixture of terpenes), gum (a viscous exudate composed of polysaccharides [complex sugars]), volatile oil, and mostly small amounts of other substances.

According to the American Botanical Council (ABC), retail sales of boswellia dietary supplements have seen a rapid increase in the early and mid-2010s in the U.S., particularly in the mass market retail sales channel, but sales have since leveled off or even decreased. After 2019, boswellia dietary supplements have dropped out of the top-selling 40 botanical ingredients. In 2021 retail sales in the U.S. totaled US $8,940,589 in both the mass market and natural channels combined.

Published data on boswellia adulteration have focused mainly on the undisclosed admixture or substitution with oleogum resins from other Boswellia species, in particular B. frereana, B. papyrifera, and B. sacra. These materials may be used as legitimate substitutes in cases where there are locally accepted interchangeable uses. Sometimes they can be used as adulterants, if their inclusion is not transparently disclosed on certificates of analysis or on ingredient labels, possibly due to local supply shortages or misidentification of B. serrata along the supply chain.

The new LGD was written by Nilüfer Orhan, PhD, an expert in natural products chemistry and analysis, with contributions from Burak Temiz, Hale Gamze Ağalar, PhD, and Gökalp İşcan, PhD, from Anadolu University in Eskişehir, Turkey. It provides an evaluation of 46 analytical methods with respect to their suitability to authenticate Boswellia serrata oleogum resin and its extracts.

Of note, the LGD features images of a side-by-side HPTLC (high-performance thin-layer chromatography) fingerprint comparison of B. serrata and seven other Boswellia species, as well as myrrh (Commiphora myrrha). These HPTLC images were developed specifically for BAPP for the boswellia LGD. Twenty-four experts in quality control of medicinal plants from academia and the herb industry in the U.S. and internationally provided peer-review input on the document to ensure its accuracy and relevance to current global market conditions.

“Because of their morphological and chemical similarities, and similar medicinal uses, a host of oleogum resins were historically traded interchangeably and often without botanical specificity,” noted Roy Upton, president of the American Herbal Pharmacopoeia. “In more recent decades, Boswellia serrata has emerged as the preferred source of boswellia, at least from a nomenclatural perspective. This document is perhaps the most detailed review of the differences of these resins conducted in the English language and should give any manufacturer using a boswellia ingredient clarity of what it has, as well as perhaps expand specifications to allow for the interchangeable use of those species that are most similar.”

Stefan Gafner, PhD, chief science officer of ABC and technical director of BAPP, commented: “Two issues make the authentication of Boswellia serrata extracts particularly challenging. Some of the published data on the contents of the purported anti-inflammatory constituents, the boswellic acids, in Boswellia species appear to be based on erroneous species identification. Therefore, the exact composition of the confounding species can be difficult to determine. Additionally, some of the commercial extracts are processed in a way that alters the relative amounts of the naturally-occurring boswellic acids, leading to a proprietary ingredient that has a very different composition than what is found in the oleogum resin. We hope that the information provided in the new BAPP LGD addresses these and other issues and will be of use to quality control analysts working with Boswellia serrata-derived ingredients.”

As with all BAPP publications, LGDs are freely accessible to all ABC members, registered users of the ABC website, and all members of the public on the program’s website (registration required).