The problem of interaction plant-medicine lies in terms of mere theories poorly reasoned, and in some misguided experimentation and based on inaccurate premises.
To convey the message that this problem is rooted in scientific Fundamentals using sophisticated classification and indecipherable by the majority of the population and even some health professionals clarified, resorting excessively to the physiology and biochemistry, but always with a lot of inaccuracy, Sometimes the streak fantasy.
On the other hand excessively used terms such as; can; It is suggested or suggestive, possibly, Maybe, etc., in studies and exhibitions in lectures.
Any argument that often use these terms is fallacious and can never be based on solid scientific bases. We are in the realm of supposition and even empiricism is relevant.
However many of these studies refer to substance use isolated and purified from plants, as is the case of the ginkgobilósidos of ginkgo biloba and highly standardized extracts, as is the case of hypericin in hypericum perforatum or kawalactonas of piper methysticum (the scheme).
This type of products have no use in food supplements and should be considered as pharmaceuticals, Since it does not correspond to "totum vegetal"[1] the original plant and which serves as a traditional reference as to its use, being so referencing with regard to their safety, including with regard to a possible interaction with drugs (drugs).
Sometimes arrive at the exaggeration to consider supposedly some vegetables, as the citrus limonum (aka lemon), allium sativum (aka garlic) and official "zinziber" (aka ginger), possibly responsible for serious interactions with certain drugs. The use of these foods to the national and world level in juices and spices, try irrefutavelmente, that's in the realm of fantasy and even fallacy. Of course there are plants with relevant toxicological effects.
Intending to approach with objectivity and scientific rigor, This issue, We will then analyze various vegetables in respect of any plant interactions-drug taking as a source of the meta-study analytical work,[2] "Interections Between Herbal Medicines and Prescribed Drugs Updated Systematic Review", prepared by the Department of experimental Pharmacology, University of Naples in Italy, in partnership with the universities of Exeter and Plymouth in the United Kingdom. This work proves to be paradigmatic, to the extent that, is a comprehensive collection of data on hundreds of other research papers, many of them experimental.
- Equinacea (And. Purple; And. Angustifolia e E. Pallida). The collection of data about this vegetable ends noting that the evidence suggests that echinacea does not put a risk to patients on concomitant use with drugs. To reach this conclusion however addressing multiple jobs with transient results, involving metabolic chains always where the citrocromos always appear as players preferred research biochemicals, adding however that echinacea does not affect the pharmacokinetics of Digoxin, a substrate of P-Glicoproteina another entity biochemistry very used in these studies of planta medicinal product interaction.
- Garlic (allium sativum). In this study the excessive use of the terms "can" and "suggests" is indicative of the uncertainty about the interactions. However we underline some passages also many revealing. A study suggests that garlic can affect platelet function (aggregation of blood platelets), causing effects on coagulation with risk of bleeding, However, two studies conclude that the garlic does not alter the pharmacokinetics of warfarin or pharmacodynamic (an anticoagulant) and that this vegetable does not put serious risks of bleeding in patients monitored with medicines such as warfarin.
Garlic appears in some studies as supposedly able to interfere with the metabolism, via citocromos and p-glycoprotein substratos, the squinavir (a retroviral used in hiv-positive). However added that the experimental evidence in humans does not confirm this hypothesis, and that the reason for these discrepancies is not clearly clarified. The study about the garlic just referring to in relation to hypothetical effect excessively anticoagulant, When administered with medicines (drugs) anticoagulants, has not been confirmed in clinical studies.
- Ginkgo (ginkgo biloba). Here is once again raised the possibility of interaction with anticoagulants, through the mechanism of platelet aggregation. Note that in this case the only conclusive studies were obtained with experimental use of isolated ginkgolidos, What, as already mentioned earlier in this article, does not constitute proof of interaction of any dietary supplement, to the extent that in supplements only if uses the total extract (vegetable Totum) of ginkgo biloba. However still refers to recent studies do not confirm these effects, and that no significant correlation between the time of bleeding and the platelet aggregation inhibition, adding that a systematic review of eight randomized studies, concludes that the evidence does not demonstrate that the extract of ginkgo biloba can cause significant changes in blood coagulation parameters. The valproico acid and fenitoina (two antiepiléptics) also appear as possible targets of interaction of ginkgo biloba, In conclusion-if however that fluctuations in organic concentrations, These two substances cannot be definitely attributed to plant interactions-medicine.
- Ginseng (panax ginseng). The text draws attention to the use of these standardized extracts studies on ginsenosides. If these extracts are highly standardized, as already mentioned, they go beyond the principle of using "totum vegetal", reference to the dietary supplements, and even should be the target of concern on our part. However add that in the text of this study indicated that although some studies reviewed have raised the chance of interaction, Once again with blood thinners, several clinical studies do not confirm that ginseng affects platelet function, even if I change the pharmacokinetics or pharmacodynamics of warfina (anticoagulant).
- Kava (piper methysticum). As I have previously listed with kava, have been recorded with a highly standardized extract about 85% of kavalactones, a family of Phytochemical molecules.
This type of product, as already emphasised several times in this text do not correspond to the fundamental principle of use of the total extract (vegetable Totum), simply is not used in food supplements. So we will be focusing on this issue.
- Serenoa (serenoa repens bartram). The study States that there is no clinical evidence that would reveal any kind of interaction plant-medicine.
Concluding that “These two clinical studies show that this vegetable has no significant effects in the cytochromes P1A2; P2d6; P2E1 or P3A4 in volunteers tested, and experimental research substrates benzodiazepines like Alprazolam, e o Midazolam, and still other drugs like Chlorzoxazone, the Debrisiquina and Destrumetorfano”.
- Wort St. John (hypericum perforatum). The study indicates that the single use, has an appropriate security profile. However also points out that there is the possibility of the existence of interactions with medicines, and that these seem to be due to the ability of this plant to induce the enzymes citocrómicas and P-Glicoproteina intestinal level. The studies on a series of medications such as digoxin, Fexofenadine and Talinolol are contradictory, Since some demonstrate a low plasma concentration of substrates of P-Glicoproteina, While Interestingly other studies concluded there had been a stimulus and even there has been any effect. Finally the clinical evidence suggests that the content of hiperforina (existing molecule in the extract) is crucial in the processes of interaction plant-medicine, to the extent that, low-hiperforina extracts (those used in food supplements) have a very weak or non-existent effect on P citrocromo and P-Glicoproteina; working-if even that these extracts do not modify plasma concentrations of oral contracetivos (aka pill).
There is even a study that indicates there is an effect otherwise type. In this study the Carbamazepine used during 7 days decreases significantly the plasma concentrations of Pseudohipericina (an existing molecule in the extracts), this case represents a situation in which a synthetic drug affects the physiological effects of a substance on a vegetable extract. This review study on hundreds of other studies, concludes that many of these publications are of poor quality and omit important details and the most detailed ever bother to establish the ratio effect concluding that one cannot extrapolate the results obtained with a particular vegetable preparation, for all other existing.
Finally we couldn't stop and add that there is absolute proof of plant interactions- medication, the obligation to refer to such a situation in packaging (literatures) must be burden of medicine and not of the product (dietary supplement or food) containing plants. In fact this is already common practice in various situations, as for example; tetracyclines should not refer to ingest milk and its derivatives because they are rich in calcium, which decreases the absorption of these antibiotics; of IMAO (mono aminaoxidase inhibitors), Antidepressants to warn that should not eat many foods rich in amines by suffer inhibition in catabolização, concentrate in the body and can cause headaches (headaches).
[1] See article on “totum vegetal”.
[2] We cover only plants, that are currently further speculation, on problematic interaction plant-medicine.
Author > Eduardo Ribeiro, CEO scientist Department | Quality control| Research and Development- Biogal, Biologia de Portugal Lda.
