Natural Products for Cancer Therapies: From Good to Bad Perspectives
Parat F, Kovacic H*
Aix-Marseille University, France
*Corresponding author: Hervé Kovacic, Professor, Institute of Neurophysiopathology (INP), Aix-Marseille University, Marseille 13385, France
Article History
Received: August 12, 2021 Accepted: September 30, 2021 Published: October 01, 2021
Citation: Parat F, Kovacic H. Natural Products for Cancer Therapies: From Good to Bad Perspectives. Int J. Res. Case Rept & Case Sers. 2021;1(1):21‒22. DOI: 10.51626/ijcrs.2021.01.00005
Abstract
Nutrition and the control of food inputs are key elements of human health. The general public is eager for products and dietary supplements that are touted to maintain good health. Antioxidants, vitamins and other natural product derivatives are now available to everyone at the click of a mouse. Randomized studies showing positive preventive effects of these molecules on human health are few and mostly inconclusive. The people most attracted to the use of these supplements are often people suffering from a pathology and seeking to improve their health in parallel with their medical treatment. The evaluation of the impact of these supplements on the efficacy of treatments is rarely evaluated and for many compounds there is a strong scientific basis for considering deleterious effects, especially for treating cancer patients. This article aims to highlight some important points of attention that every general practitioner or clinical oncologist should have regarding the nutrition of their cancer patient under treatment.
Opinion
Nature is an important source of therapeutic molecules. Since the dawn of humanity, plants, mushrooms, and roots have been used for therapeutic purposes. Analyses of human fossils show that as early as the Paleolithic, the Neanderthal occupants of El Sidrón used plants to treat their diseased teeth [1]. The birth of medicine and pharmacology took place in all civilizations and pharmacognosy represented for a long time the only source of active molecules before chemical drugs took over. Many compounds of the pharmacopoeia were initially derived from plant products. Aspirin extracted from white willow, opium from the white poppy giving morphine and codeine, quinine from cinchona, taxol from yew, vincristine from periwinkle, colchicine from colchicum or digitalis from foxglove.
The development of mankind’s therapeutic arsenal began with very empirical approaches that multiplied the number of pharmaceutical products and evolved towards a rationalized approach that culminated in the double-blind randomized controlled trial. This modern approach seeks to identify the superiority of a drug treatment with the least possible bias.
In addition to modern chemical molecules evaluated by clinical trials, research into active compounds from plants remains very active. These compounds are often antioxidants. Indeed, a deregulation of redox homeostasis is observed in many pathological situations ranging from neurology to cancerology, including diabetes, nephropathy, or cardiovascular pathologies. The activity of these molecules is explored both for their preventive and curative properties. Among these derivatives, we frequently find flavonoids, carotenoids, cucurmin, cathechins, phycocyanins. On the preventive aspect, there are few randomized studies, and these do not show superiority of antioxidant supplementation on health parameters and human survival (see for example the suvimax and suvimax2 studies [2]). On the curative aspects, the scientific community has published a great deal of preclinical work extolling the miraculous character of these molecules on various pathologies. However, there are few trials to evaluate their clinical effectiveness. Some compounds such as catechin derivatives (from green tea) have been able to progress to phase I and II trials [3], but many other compounds have not had this chance due to the absence of effect or even the demonstration of deleterious effects (such as the ATBC and CARET studies for beta-carotene).
All of this information taken up by mainstream newspapers associated with the marketing of companies selling these food supplements boast despite all the positive effects of these products on human health. If it is not harmful to take an ineffective product when one is in good health, it is different for subjects suffering from diseases such as cancer, for which the effectiveness of the best molecules is still below what one would expect. It is now well documented that many antioxidant agents can limit the efficacy of cancer radiotherapy and chemotherapy [4] and the mechanisms of these effects have been described in certain cancer models [5,6]. It therefore seems urgent to improve information to patients concerning the risk of using non-assessed natural products when undergoing anticancer treatment. This message should be conveyed by the clinical oncologist during treatment, but also by the general practitioner who follows the patient on a long-term basis, preferably in association with a nutritionist. A good public health approach should even monitor the diets of patients included in a clinical trial of an anticancer agent in order to control the intake of components that may have significant effects on the efficacy of the therapy. In view of the search for alternatives to chemotherapy by patients and in view of a communication leading to a significant consumption of these products, for patients undergoing chemotherapy, it is also urgent to evaluate the impact of these products in association with anti-cancer chemotherapies.
Is the situation of a cancer patient undergoing chemotherapy taking dietary supplements or antioxidants outside of medical control a rare case or does it represent many patients treated?
Let’s take the case of a product in strong development whose qualities for health are praised all over the communication space: Spirulina and its main active component C-phycocyanine. This product is presented as a nutritional miracle because it contains three times more protein than the same amount of beef and requires almost thirty times less water than soy to develop. In terms of health, Spirulina has antioxidant, anti-inflammatory and anti-cancer activities (inhibits proliferation, induces apoptosis). In the year 2021, there are more than one thousand articles in the Pubmed database showing the beneficial effects of Spirulina, of which more than five hundred show an anti-cancer activity. Similarly, nearly three hundred articles are published on the effects of C-Phycocyanine. The scientific community is therefore very rich in information that points to a possible medical interest of these compounds. It should be noted, however, that little data is yet available on the impact of these compounds in combination with chemotherapy. The world production of Spirulina is around 5000 tons and has been constantly increasing for several years.
So the consumption of spirulina by patients undergoing chemotherapy is far from negligible if no information action is organized at the medical level. In view of the increasing demand for the use of such products by the population, it would of course be important to be able to evaluate the harmlessness of the association of spirulina with anticancer treatments. The cost of such an evaluation makes it difficult and only a public health organization can finance this type of study. While waiting for such results, hospital practitioners should alert their patients and start a massive information campaign to warn them of the potential risk of using these compounds during cancer chemotherapy.
References
- Karen Hardy, Stephen Buckley, Matthew J Collins, Almudena Estalrrich, Don Brothwell, et al. (2012) Neanderthal medics? Evidence for food, cooking, and medicinal plants entrapped in dental calculus. Naturwissenschaften 99(8): 617–626.
- Hercberg S, Galan P, Preziosi P, Bertrais S, Mennen L, et al. (2004) The SU.VI.MAX Study: a randomized, placebo-controlled trial of the health effects of antioxidant vitamins and minerals. Arch Intern Med 164(21): 2335-2342.
- Saleh A Almatroodi, Ahmad Almatroudi, Amjad Ali Khan, Fahad A Alhumaydhi, Mohammed A Alsahli et al. (2020) Potential Therapeutic Targets of Epigallocatechin Gallate (EGCG), the Most Abundant Catechin in Green Tea, and Its Role in the Therapy of Various Types of Cancer. Molecules 25(14): 3146.
- Brian D Lawenda, Kara M Kelly, Elena J Ladas, Stephen M Sagar, Andrew Vickers, et al. (2008) Should supplemental antioxidant administration be avoided during chemotherapy and radiation therapy? J Natl Cancer Inst 100(11): 773-783.
- Laetitia Dahan, Amine Sadok, Jean-Louis Formento, Jean François Seitz, Hervé Kovacic (2009) Modulation of cellular redox state underlies antagonism between oxaliplatin and cetuximab in human colorectal cancer cell lines. Br J Pharmacol 158(2): 610–620.
- Mathieu Chocry, Ludovic Leloup, Hervé Kovacic (2017) Reversion of resistance to oxaliplatin by inhibition of p38 MAPK in colorectal cancer cell lines: involvement of the calpain / Nox1 pathway. Oncotarget 8(61): 103710–103730.
