on July 24, 2026
Phytotherapy, from the Greek phytòn (plant) and therapéia (cure), is a scientific discipline based on the use of medicinal plants and their derivatives for prevention, treatment, and support of psycho-physical well-being. In the modern landscape of integrative medicine, phytotherapy and biomolecular nutrition are widely used by cancer patients to mitigate the toxicity of conventional treatments, enhance the immune response, and modulate the cell signaling pathways involved in tumorigenesis.
The phytotherapeutic and phytochemical products most commonly used in clinical oncology and integrative experimental protocols include:
· Artemisia (Artemisia annua): Shows antiproliferative and pro-apoptotic activity in prostate, breast, and colon carcinomas through the generation of iron-dependent ROS; however, it requires rigorous hepatosplenic, cardiac, and renal monitoring.
· Astragalus (Astragalus membranaceus): A cornerstone of traditional Chinese medicine, it directly inhibits neoplastic growth and is used in lung cancer to contain immunosuppression.
· Aloe Vera and Aloe Arborescens: Reconstitutive and immunomodulating substances used to promote post-chemotherapy organ recovery.
· Garlic (Allium sativum L.): Known for its antibacterial and cardioprotective action, it contains sulfur molecules suitable for inhibiting carcinogenesis.
· Boswellia serrata: Rich in boswellic acids with anti-5-LOX activity, it is preferentially used for peritumoral edema and glial tumors.
· Curcumin: A polyphenol extracted from Curcuma longa with anti-inflammatory, pro-apoptotic, and anti-angiogenic activity.
· Echinacea (Echinacea purpurea/angustifolia): Used as a non-specific immunostimulant and systemic anti-inflammatory.
· Ginseng (Panax ginseng): Used in the treatment of cancer-related fatigue and to improve the immune profile.
· Hypericum perforatum (St. John's Wort): Used in mild or moderate depressive syndromes related to cancer diagnosis.
· Kava (Piper methysticum) and Valerian (Valeriana officinalis): Used for the modulation of anxiety, psychological distress, and insomnia.
· Mistletoe (Viscum album): Extensively studied for the reduction of chemotherapy toxicities and the improvement of quality of life.
· Ginger (Zingiber officinale): Effective natural antiemetic in the management of chemotherapy-induced nausea (CINV).
In the seeds of Nigella sativa (SNS) and sesame, thymoquinone (TQ) represents the best-characterized bioactive compound. TQ acts as a pan-inhibitor of prostaglandin synthesis, simultaneously blocking the cyclooxygenase (COX) and lipoxygenase (LOX) enzymatic pathways, although its complex molecular pathways of neoplastic suppression are still under thorough investigation.
Selenium is an essential trace element without which the body cannot synthesize the selenoproteins essential for thyroid and redox homeostasis, such as glutathione peroxidase and thyroid peroxidase (involved in the modulation of T3, T4, and thyroglobulin) and iodothyronine deiodinase (necessary for the conversion of T4 into the active T3 form). A selenium deficiency compromises the endocrine balance, increasing susceptibility to autoimmune thyroid diseases. Elimination occurs mainly through the kidneys; therefore, the recommended RDA is 55 µg/day in adults, increasable to 60-70 µg/day during pregnancy and breastfeeding. Primary sources of selenium are Brazil nuts, peanuts, eggs, whole wheat, bran, barley, brewer's yeast, legumes, garlic, onion, mushrooms, and oilseeds (sesame and sunflower). The actual content in foods depends heavily on soil geochemistry: the high presence of contaminants or sulfur (from acid rain, fertilizers, or volcanic soils) tends to complex and inactivate selenium, reducing its plant uptake.
Among the Liliaceae, garlic (Allium sativum L.) exerts antitumor properties derived from organosulfur compounds. When the bulb matrix is damaged, allicin is released, which quickly transforms into sulfur derivatives capable of blocking the enzymes responsible for the activation of carcinogens, facilitating DNA repair, slowing the progression of the cell cycle, and stimulating the selective apoptosis of mutated cells without affecting healthy tissues. In the World Cancer Research Fund (WCRF) report, a diet high in garlic is associated with a probable reduction in the risk of colorectal cancer, with promising evidence also for esophagus, pancreas, breast, endometrium, and prostate.
Similarly, onion (Allium cepa L.) provides sulfur compounds capable of suppressing cell proliferation in breast carcinomas. Onion represents the main source of quercetin, a flavonoid with pronounced anti-inflammatory and insulin-sensitizing activities (also present in asparagus). Quercetin acts by activating the AMPK protein kinase and modulating sirtuins (SIRT1/SIRT2), preventing aberrant adipogenesis and conferring important cardio-metabolic protection.
Apple (Malus domestica, Rosaceae), with particular reference to the Annurca variety, is rich in polyphenols capable of interfering with DNA replication in colorectal cancer cells, countering the formation of intestinal polyps through genomic hypomethylation with mechanisms similar to some new-generation antineoplastic drugs. Fisetin present in apples and strawberries induces tumor apoptosis and acts as a fasting mimetic on longevity genes. The presence of quercetin inhibits the expression and activity of COX-2, while the abundant pectin fraction in the peel supports the eugenic composition of the intestinal microbiota.
On the nutritional level, the reduction or elimination of red meat is supported by precise pathophysiological evidence: it contains high levels of arachidonic acid, a polyunsaturated fatty acid with pro-inflammatory action, concentrated especially in intensively farmed animals fed with corn-based feeds rich in Omega-6. Such foods can carry lipophilic dioxins and pesticides that accumulate in adipose tissue. Furthermore, red meat is rich in heme iron, a powerful pro-oxidant agent that catalyzes the formation of carcinogenic nitrosamines in the intestinal lumen.
Aloe Arborescens administered in association with conventional oncological therapies significantly improves the "quality of life" score and the EORTC performance status in cancer patients, mitigating the systemic toxicity of antineoplastic and radiotherapy treatments. The phytocomplex of Aloe Arborescens is rich in aloe-emodin (an antiproliferative and pro-apoptotic agent) and radioprotective antioxidant molecules. The leaves must be harvested from 5-7 year old plants: before 4 years, aloin is highly concentrated and can cause colic and diarrhea; with maturation, the plant transforms aloin into aloe-emodin, which is free of intestinal toxicity and endowed with direct tumor cytotoxic activity. Aloe Arborescens also demonstrates immunostimulant and antimicrobial properties, inhibiting the growth of Streptococcus and Shigella and protecting the gastrointestinal mucosa.
The mechanisms of action of curcumin include the inhibition of neoplastic proliferation and transformation, the activation of apoptosis, the blocking of tumor angiogenesis, the suppression of metastatic migration, and the downregulation of the NF-κB pathway. Administered in combination with conventional chemotherapy, curcumin exerts a strong chemo-sensitization effect: in association with cisplatin, for example, it enhances the suppression of squamous cell carcinoma head and neck cell lines.
In integrative mycotherapy, Shiitake (Lentinus edodes) contains eritadenine and the beta-glucan lentinan, which activates macrophages, T lymphocytes, and cytokines (IL-1, IL-2). In advanced gastric and colorectal carcinomas, combined with chemotherapy (e.g., S-1), it prolongs overall survival and reduces nausea and pain. Reishi (Ganoderma lucidum), rich in triterpenes (ganoderic acids) and polysaccharides, increases the cytotoxicity of Natural Killer (NK) cells and the levels of IL-2, IL-6, and IFN-γ in cancer patients, exerting a synergistic action with chemotherapy in lung cancer. The association of purified mushroom extracts with Wasabi (Eutrema japonicum) exerts a suppressive action on oncogenes and positively modulates estrogen metabolism.
In the field of symptomatic support, pollen subjected to decortication has proven to be a safe and effective supplement in cancer patients or those on hormone therapy, reducing the frequency and intensity of hot flashes and iatrogenic menopausal vasomotor disturbances.
Regarding the properties of Green Tea (Camellia sinensis), research conducted at the Karolinska Institute demonstrates that epigallocatechin-3-gallate (EGCG) blocks tumor angiogenesis by inhibiting neovascularization, while studies by the Cancer Chemotherapy Center in Tokyo highlight the direct inhibition of telomerase. Clinical meta-analyses indicate that high green tea consumption (≥5 cups/day) is associated with a significant reduction in the risk of lung and breast cancer.
Cruciferous vegetables (Brassica oleracea, including broccoli, cauliflower, Brussels sprouts, and turnips) contain high concentrations of glucoraphanin, a precursor of sulforaphane. Rich in vitamins A, C, K, and minerals, broccoli also provides phytoestrogens and indole-3-carbinol, which can counteract hormone-dependent cancers (breast and prostate) and protect the digestive tract from oxidative stress by activating the Nrf2 pathway.
Finally, a recent double-blind randomized clinical pilot study conducted on patients who had undergone surgery for colorectal cancer evaluated the ex vivo administration of Graviola leaf extract (Annona muricata for 8 weeks). The serum of treated patients showed significantly greater cytotoxicity against the COLO 205 and DLD-1 tumor cell lines compared to the placebo (p=0.013). Although these pilot data suggest potential therapeutic doses equivalent to 1030 mg of annonacin, clinical caution is recommended due to possible hypotensive side effects and the extract's drug interactions.
Main Bibliographic References Cited in the Document
1. Lissoni P, et al. A randomized study of chemotherapy versus chemotherapy plus Aloe arborescens in patients with advanced solid tumors. In Vivo, 2009; 23(1): 171-175.
2. Indrawati L, et al. Ex-vivo cytotoxicity of Annona muricata leaf extract in colorectal cancer patients: A randomized pilot study. BMC Complementary Medicine and Therapies, 2017; 17(1): 320.
3. Gupta SC, et al. Multitargeting by curcumin and chemosensitization with cisplatin in head and neck cancer. AAPS Journal, 2013; 15(1): 195-218.
4. Rayman MP. Selenium and human health. The Lancet, 2012; 379(9822): 1256-1268.
5. Ina K, et al. The use of Lentinan for treating gastric cancer. Anticancer Agents in Medicinal Chemistry, 2013; 13(5): 681-688.
6. Cao Y, et al. Green tea leaves inhibit angiogenesis in cellular models. Nature, 1999; 398(6726): 381.
