| Date: 07-13-2018 | HC# 121733-596 |
Nunes
MA, Rodrigues F, Alves RC, Oliveira MBPP. Herbal products containing Hibiscus sabdariffa L., Crataegus spp., and Panax spp.: Labeling and safety concerns. Food Res Int. October 2017;100(Pt 1):529-540. doi:
10.1016/j.foodres.2017.07.031.
Hibiscus
(Hibiscus sabdariffa, Malvaceae), hawthorn (Crataegus
spp., Rosaceae), and ginseng (Panax
spp., Araliaceae) have been studied for their beneficial effects on
cardiovascular health. They are the main ingredients in various herbal products,
some of which claim to improve cardiovascular disease (CVD) risk factors such
as hypertension and dyslipidemia. Concomitant use of medicines and herbal
products may bear some risks. The authors reviewed herbal and herbal/fruit
products available in Portugal containing hibiscus, hawthorn (C. monogyna),
and Asian ginseng (P. ginseng);
critically analyzed the product labels; assessed the cardiovascular effect of
the products; and analyzed the current market for these products.
Products
were randomly selected from six supermarkets and three herbalist shops in
Porto, Portugal, during April and May 2016. Fifty-two products for infusion
preparation, from 22 commercial brands, were found to contain herbs
individually or in mixtures. Thirty included hibiscus, 16 contained hawthorn,
and six contained Asian ginseng. For each product, the authors recorded label information
about ingredients, plant part(s), form, and preparation recommendations. They
evaluated statements or claims referring to health conditions and warnings for
specific health or well-being disorders. Not all products specified the plant's
scientific name. For 33 products, only the common name was used. For five
products, although the product name referred to one plant, several plants were
named as ingredients. Ten products did not list the main ingredient on the
front label.
Of
the total ingredients, proportions ranged from 1% in a mixture of ginseng,
honey, lemon (Citrus × limon, Rutaceae), and
green tea (Camellia sinensis,
Theaceae), to 100% in three hibiscus products. Four products contained hibiscus
extracts while none contained hawthorn or ginseng extracts. Nineteen products
did not describe the amount of plant or plant part used.
A
meaningful assessment of representative chemical constituents and plant effects
is confounded by the variety of bioactive compounds found in these plants due
to cultivation and climate conditions, plant genetics, metabolic pathways,
harvesting practices, and method of analysis. Comparing studies of the plants is
also impeded by varying sample preparation, solvents and sample/solvent ratios,
method of extraction, and analytical
methods used.
Hibiscus
is used worldwide to treat hypertension and dyslipidemia. Hibiscus beverages
are usually prepared by decoction or infusion of its calyxes and leaves. Its
flowers contain phenolic acids, flavonoids, and anthocyanins. The calyxes have
a lower content of flavonoids and glycosides. Various studies have evaluated
the effects of hibiscus compounds on the cardiovascular system, with some
investigators attributing its protective cardiovascular properties to its anthocyanins.
Among the potential mechanisms for its antihypertensive, antioxidant, and hypolipidemic
properties are direct effects on vascular muscles, calcium channels, and cholinergic
and histaminic activity. Of the 30 products with hibiscus as the major
ingredient, six products did not name the plant on the front label. The flower
was the most common part listed, with only one product containing leaves. One product
claimed tonic properties and improved circulation. Recommended dosages and
preparation instructions were indicated on the labels.
Hawthorn
is used in infusions, tinctures, standardized extracts, dietary supplements,
authorized prescription drugs, and herbal medicinal products for its
cardioprotective effects. Among the many bioactive compounds identified in the
species are oligomeric procyanidins, flavonoids, catechins, and sugars, which
are found in the berries, leaves, and flowers. The species' beneficial
cardiovascular effects are attributed to their antioxidant, anti-inflammatory,
antiplatelet aggregation, vasodilating, antiarrhythmic, lipid-lowering, and
endothelial protective properties; positive inotropic action; reduced smooth
muscle cell migration and proliferation; protection against
ischemia/reperfusion injury; and a decrease
of arterial blood pressure. The 16 samples in this study contained flowers,
leaves, and fruits, up to a proportion of 35%. Five products included
statements related to cardiovascular conditions, such as "supports the
normal function of the arteries," "important for […]
arrhythmias," and "supports cardiac function, increases the oxygen
flow and improves peripheral circulation." The authors found some of these
claims misleading.
Ginseng
contains ginsenosides, a group of triterpene glycosides, which are present in
the root, leaf, and berry. The various ginsenoside structures are associated
with different mechanisms and pharmacological effects, probably due to their
antioxidant, anti-inflammatory, immunostimulatory, and antihyperglycemic
activities. Inconsistent study outcomes may be attributed to the structural
heterogeneity of the ginsenosides, their multiple mechanisms, and the various
experimental methodologies used to evaluate their activities. Fourteen products
containing ginseng presented cautionary statements such as, "It is
advisable to consult a doctor or a dietitian whenever you have questions about
the consumption of this product" and "This tea should not be taken by
individuals with low blood pressure."
European
regulations stipulate that nutrition and health claims must be scientifically
valid or proven, useful, reliable, and comprehensible to consumers. The European Medicines Agency’s
monographs cover therapeutic uses and safe conditions of well-established and
traditional applications for herbal preparations. Some statements and claims on
products included in this study corresponded to EU herbal monographs.
The
herbs described in this study "seem to have potential benefits for CVD and
can draw the consumers' attention," write the authors. Of concern are consumers
with a cardiovascular disorder, who are being treated with conventional medications,
and who take herbs regularly, but do not know the herbs present in the products
they take. A lack of information may lead to adverse effects from herb-drug
interactions and other potential side effects. Although some adverse effects
and herb-drug interactions have been reported, findings suggest only nonsignificant
evidence of interactions between drugs and hibiscus. Hawthorn is well-tolerated
and free from significant adverse effects. However, some adverse effects
reported include headache, rash,
palpitations, and gastrointestinal upset. It may also interact with
antihypertensives, antilipemic drugs, beta-blockers, digoxin, vasodilators,
anticoagulant, and antiplatelet drugs. Patients who consume ginseng products
along with anticoagulants, antidepressants, antidiabetics, antilipemic drugs,
calcium channel blockers, digoxin, or diuretics should be monitored. "[…] consumers
with some sort of cardiovascular dysfunction and/or under medication treatments
should be aware to carefully analyze the labels and consult additional
information related to these herbal products," state the authors.
Manufacturers should provide awareness statements, and health professionals should
caution their patients about possible herb-drug interactions, according to the
authors. Additional studies and clinical trials are needed to better understand
the effects of herbs and to provide science-based guidance to assess their
safety.
—Shari Henson
