FWD 2 HerbalGram: Adulteration of “Grapefruit Seed Extract,” etc.


Issue: 94 Page: 6

Adulteration of “Grapefruit Seed Extract,” etc.

by Mark Blumenthal

HerbalGram. 2012; American Botanical Council



As a part of our ongoing series dealing with accidental and intentional adulteration of botanical raw materials sold for a variety of uses (e.g., food flavors, dietary supplements, cosmetics, non-prescription medicines, et al.), we present John Cardellina’s review of 10 analytical papers published since 1991 on an ingredient called “grapefruit seed extract,” for which the results show that many or possibly most of these materials appear to have been adulterated with synthetic industrial disinfectants like triclosan, benzalkonium chloride, and/or benzethonium chloride. According to all of the available papers reviewed in this article, one or more of these synthetic compounds appear in most of the analyzed samples; however, none of these synthetic disinfectant compounds were found in extracts made in the research laboratories from actual grapefruit seeds (Citrus x paradisi), and all of the “grapefruit seed extracts” that did not contain the synthetics exhibited no experimental antimicrobial activity. This evidence is strongly suggestive of intentional adulteration. This situation is especially curious, given the fact that there does not appear to be any historical or traditional medicinal use of grapefruit seed, or preparations made from it in any treatises or monographs in traditional literature, pharmacopoeial compendia, etc.

Information on the Internet, some of it associated with companies that market GFSE, claims that these compounds are produced by a proprietary chemical process from the naturally occurring chemicals in grapefruit seeds. Dr. Cardellina and other chemical experts with whom we have consulted believe that such chemical synthesis does not conform with any known chemistry or chemical pathways.

It is unclear to what extent any products currently sold in the market in the US and elsewhere reflect the chemical profiles found in any of these analyses, or to what extent, if any, there may be safety concerns. To date, there does not appear to be. Nevertheless, in our view, this is a matter of possible misbranding or adulteration or both that should be immediately researched by the Food and Drug Administration (FDA), and, if FDA analyses confirm those that are summarized in this article, regulatory action should be taken.

Some of the publications reviewed in Dr. Cardellina’s article use the acronym “GSE” to refer to grapefruit seed extract. This same acronym has also been used to describe grape seed extract—an entirely different material from an entirely different plant—i.e., grapes (Vitis vinifera) instead of grapefruits. Accordingly, we have created a new acronym, GFSE, instead of using GSE, to refer to the so-called grapefruit seed extract and we invite our colleagues in academia, the health professions, industry, and elsewhere to do the same in future publications and communications.

And, speaking of adulteration, as we were going to press, following months of controversy in the dietary supplement industry in the US and elsewhere, FDA issued Warning Letters to 10 companies that produce and/or market the controversial compound called DMAA (1,3 dimethylamylamine; or MHA, methylhexaneamine), an ingredient that has been sold in various sports workout products. According to FDA, the companies failed to provide New Dietary Ingredient Notifications 75-days prior to marketing the ingredient, which some of the companies claim is derived from the oil of geranium (Pelargonium graveolens). However, numerous ABC scientific advisors and other plant and chemical experts have stated that DMAA is not a naturally occurring compound, and is presumably synthetically chemically produced. And, consistent with this position, we recently learned of the forthcoming publication of geranium oil from vouchered geranium specimens showing no presence of DMAA. Industry-oriented e-newsletters are rife with stories on FDA’s action, also emphasizing FDA’s position that the synthetic nature of the DMAA in and of itself is also grounds for FDA’s wanting to remove it from the market as a dietary ingredient. The FDA’s new policy of viewing synthetic botanical constituents as non-dietary ingredients remains a disputed issue within segments of the dietary supplement industry. DMAA was researched as a potential substitute for ephedrine in the late 1940s.

Our cover story this issue is Simon Jackson’s extensive review of the ethnobotany, chemistry, and pharmacology of various plant parts from the sausage tree (Kigelia africana, syn. K. pinnata), a traditional herbal remedy from many areas of sub-Saharan Africa. The highly versatile sausage-shaped fruits and other parts of this tree cover a wide range of cultural uses and are being introduced into the US and elsewhere.