Prof. Marco Biagi
Pharmaceutical Biology Unit – Dep. of Physical, Earth and Environmental Sciences – University of Siena
There phytotherapy is officially defined by the World Health Organization (WHO), the European Medicines Agency (EMA) and the Italian Medicines Agency (AIFA) as a medical discipline that uses medicinal plants and their preparations for therapeutic purposes: no distinction in official medicine , only the particularity of using a “phytocomplex “instead of a monomolecular drug (Biagi et al., 2016).
Plants have always been the main therapeutic resource for humans , by virtue of their richness in biologically active ingredients and drug screening programs are conducted using plant substrates more and more often (Giachetti and Monti, 2005).
In this context, it is not uncommon for an extract or preparation of a medicinal plant to possess overall pharmacological characteristics that differ from those of the individual chemical constituents, but which prove to be potentially useful and ameliorative in medicine . From the point of view of the pharmacological mechanism, the action of herbal preparations, although based on mechanisms common also to synthetic drugs, differs from these in that it is essentially polyvalent . As a consequence, the pharmacological profile is characterized by a multiplicity of effects. The simultaneous presence of numerous components of different chemical nature affects both the interaction with the sites of action (pharmacodynamics) and the absorption, metabolism and elimination (pharmacokinetics) of the active ingredients, thus modulating their effects. This concept is the basis of phytotherapy and the phytotherapeutic product. The peculiarity of the phytocomplex compared to the isolated and purified compound therefore lies precisely in the “teamwork” of the different molecules it contains (Gertsch, 2011).
The medical indications for which the phytocomplex and therefore the phytotherapic are better than the single active ingredient are many and officially recognized ( www.ema.europa.eu ; www.agenziafarmaco.gov.it ; www.who.int ). Here it is appropriate to mention for example the products for venous problems, where only the simultaneous presence of molecules with vasoprotective activity, molecules with radical action scavenger and anti-inflammatory molecules can produce a relevant clinical effect: herbal remedies such as the dry extract of horse chestnut seeds, such as the purified fraction of flavonoids from Citrus , the dry extract of gotu kola aerial parts, the dry extract of bilberry fruits are reference products for the entire medical class, not only for those interested in phytotherapy. The same can be said for products for hepatoprotection products such as milk thistle fruit or artichoke leaves or flower heads, skin repair products or intestinal regularity products ranging from the vegetable fiber complex of some medicinal plants to extracts containing anthraquinone glycosides for the occasional constipation. In some cases, phytotherapics have instead an indication shared by other monomolecular drugs of consolidated use, but simply represent a different class of active ingredients with a different mechanism of action, but known and well studied clinically: this is the case of plant products with immunomodulating action such as the species of echinacea used in phytotherapy (E. purpurea , E. angustifolia , E. pallida) or pelargonium roots, or plant products for anxiety and insomnia such as valerian roots, passionflower aerial parts, lemon balm leaves, just to name the main species; again, in this context we can mention cranberry fruits for the prevention of recurrence of urinary infections or many essential oils with expectorant and balsamic action. To better understand the role of phytotherapy in modern medicine based on clinical evidence of efficacy, it must be emphasized over and over again that some therapeutic indications are exclusive to phytotherapics: adaptogens are phytocomplexes capable of centrally modulating thehypothalamus-adenohypophysis-adrenal axis and regulate cortisol levels thus allowing a better response to psychophysical stress. The best known adaptogens are rhodiola and ginseng roots, but other promising medicinal plants are emerging for their anti-stress effectiveness.
Nothing could be more wrong in saying that a phytotherapic is always safe and free of side effects, but it is true that the plant products that have been developed and are currently used are generally well tolerated and, we can say, rationally usable even in “fragile” patients. like children and the elderly.
Despite all this scientific rationale and the consolidated clinical use of phytotherapy worldwide, a recent survey conducted by the Italian Society of Phytotherapy shows that not only consumers, but also a good part of health professionals, when asked what is mean by phytotherapy, they answer that it is the natural and safe alternative to synthetic drugs; not rarely the phytotherapy is confused with homeopathy, more often assimilated to naturopathy (Petruccelli, 2019).
The confusion that arises when talking about phytotherapy derives from the non-homogeneity of plant products that are marketed and used for health in our country (Biagi et al., 2016).
A phytotherapic is by definition a drug proper, officially reported in the various world Pharmacopoeias or in reference texts such as those of the World Health Organization (WHO Monographs) and registered according to the 2001/83 / EC or 2004/24 / EC legislation.
However, even if improperly, today in Italy there is a tendency to use the term phytotherapeutic also for all other non-drug plant products, used in any case for the maintenance of health and disease prevention, primarily food supplements containing extracts or other plant preparations.
Food supplements in our country are products regulated by Directive 2002/46 / EC and its implementation, Legislative Decree 169/2004. Food supplements are defined as follows: “… concentrated source of nutrients or other substances with a nutritional or physiological effect” whether they are single or multiple compounds ( www.salute.gov.it ). The same directive 2002/46 / EC clarifies which are the nutrients and other substances that can be included in the composition of a supplement: vitamins, minerals, but not only, also amino acids, essential fatty acids, fibers and extracts of plant origin.
The vegetable substances allowed in food supplementation are those listed in attachment 1 of the Ministerial Decree of 26/07/2019. The Decree also contains warnings for some substances and any associated health claim approved by the Ministry of Health.
Vegetable products in our country therefore have the possibility of being used in different areas and represent a fundamental safeguard for health. The herbal drug is to be considered the reference to refer to when available and finds its perfect place in therapy in all indications in which it is rationally used; the food supplement, for its part, can contribute to the maintenance of health and prevent pathological degeneration, but it can also find application as a complementary support to pharmacological treatments in order to improve its effectiveness or reduce its adverse effects.
At the basis of the effective and safe use of plant products is the concept of quality . Quality controls regarding safety are mandatory for all plant products used as drugs, as well as those used as food supplements, in particular: heavy metals such as lead, mercury and cadmium and arsenic, microbial load and aflatoxins, pesticides, residual solvents and radioactivity (Italian Official Pharmacopoeia XII ed.). Otherwise, the quality controls related to efficacy vary a lot between the pharmaceutical world and that of food supplementation; herbal medicines are produced following the rules of good pharmaceutical preparation and have rigorous phytochemical controls, while in the food supplement sector the quantification of “chemical ” marker “, ie titration of the extracts, is not yet mandatory (except in the case of pre-established daily intake limits, for example hypericin or synephrine or isoflavones from soy), but it provides a first fundamental distinction between the products on the market . Titration of the constituents of an extract allows first of all to obtain the reproducibility of the biological effect, which is the basis of efficacy and safety.
Phytotherapy can best be used only by doctors, pharmacists and other professionals working in the sector when specifically trained in the sector, preferably through official university channels. This is especially true when dealing with products intended for children. In paediatrics it is essential to take note of the complexity of phytotherapy and the difficulty of using phytotherapics well and rationally, but also to be clear about the therapeutic and health potential that plant products offer.