Beyond Antioxidants: Through Non-Antioxidant Mechanisms

Yoon Hang Kim, MD, MPH

Board-Certified in Preventive Medicine | Integrative & Functional Medicine Physician

Disclaimer: This article is for educational purposes only and does not constitute medical advice. The information presented summarizes preclinical and early clinical research. Herbs and supplements discussed here should not be used as substitutes for conventional cancer treatment. Always consult your oncologist and integrative medicine physician before adding any supplement during radiation therapy, as some compounds may interact with treatment protocols. Nothing in this article is intended to diagnose, treat, cure, or prevent any disease.

Introduction: Rethinking Radioprotection Beyond Free-Radical Scavenging

Radiation therapy remains one of the most powerful tools in the oncologist’s arsenal, employed in the treatment of more than half of all cancer cases. However, one of its most significant limitations is collateral damage to normal tissues surrounding the tumor. For decades, the dominant narrative in radioprotection has centered on antioxidant activity—the scavenging of reactive oxygen species (ROS) generated by ionizing radiation. While this mechanism is undeniably important, it represents only one dimension of a far more complex biological story.

A growing body of preclinical and early clinical research reveals that many herbs and natural compounds protect normal tissue during radiation therapy through mechanisms that extend well beyond simple antioxidant activity. These non-antioxidant pathways include enhancement of DNA repair, modulation of apoptotic signaling cascades, immune system regulation, hematopoietic stem cell regeneration, anti-inflammatory cytokine modulation, and direct stem cell niche support. Understanding these mechanisms is critical for integrative oncology practitioners seeking to optimize their clients’ radiation therapy outcomes while minimizing toxicity.

This article examines the evidence for eight herbs and natural compound categories that demonstrate radioprotective effects through non-antioxidant pathways, focusing on the mechanistic sophistication that makes them particularly compelling candidates for integrative radiation support.

1. Ashwagandha (Withania somnifera): Anti-Apoptotic Signaling and Immune Modulation

Ashwagandha, the revered Ayurvedic adaptogen, has emerged as one of the most mechanistically versatile radioprotective herbs studied to date. While it does possess antioxidant properties, its radioprotective profile is distinguished by several non-antioxidant pathways that deserve particular attention.

Anti-Apoptotic Pathway Modulation

One of the most compelling mechanisms through which ashwagandha confers radioprotection is its modulation of apoptotic signaling. Research demonstrates that ashwagandha downregulates pro-apoptotic proteins including Bax and caspase-3, while simultaneously upregulating anti-apoptotic proteins such as Bcl-2 and survivin. This regulatory effect enhances cell survival in healthy tissues during radiation exposure. A 2025 study published in Natural Product Communications confirmed that ashwagandha alters apoptotic-mediated inflammatory determinants in irradiated subjects, with particular emphasis on its anti-apoptotic and anti-inflammatory properties rather than simple ROS scavenging.

Gupta et al. demonstrated that ashwagandha modulates apoptotic pathways by downregulating Bax and caspase-3 while upregulating Bcl-2 and survivin, enhancing cell survival in healthy tissues. Abdel-Hamid et al. (2025), Natural Product Communications.

Immune Modulation and Myeloprotection

Ashwagandha demonstrates significant immunostimulatory effects at doses corresponding to approximately 4–6 grams per day in humans. In cyclophosphamide-treated animal models, ashwagandha prevented myelosuppression and produced significant increases in hemoglobin concentration, red blood cell count, white blood cell count, platelet count, and body weight. This myeloprotective capacity is particularly relevant in the context of radiation therapy, where bone marrow suppression is a dose-limiting toxicity.

Dual-Action: Radiosensitization of Tumors with Normal Tissue Protection

Perhaps most remarkable is ashwagandha’s demonstrated ability to simultaneously radiosensitize tumor cells while protecting normal tissues—the holy grail of radiation oncology. Withaferin A, a key withanolide constituent, has been shown to radiosensitize renal cancer, melanoma, and lymphoma cell lines in preclinical studies. In melanoma-bearing mice, the combination of radiation, ashwagandha, and local hyperthermia produced complete tumor responses in a significant percentage of subjects. This selective effect—enhancing radiation’s impact on tumors while shielding normal cells—operates through mechanisms distinct from antioxidant activity.

Devi PU et al. (1996). Withaferin A: a new radiosensitizer from the Indian medicinal plant Withania somnifera. Int J Radiat Biol. 69(2):193-7.

Kalthur G, Pathirissery UD. (2010). Enhancement of the response of B16F1 melanoma to fractionated radiotherapy and prolongation of survival by withaferin A and/or hyperthermia. Integr Cancer Ther. 9(4):370-377.

2. Panax Ginseng: Hematopoietic Stem Cell Regeneration and Intestinal Repair

The radioprotective effects of Panax ginseng represent a paradigm case for non-antioxidant mechanisms, with its most compelling evidence centering on direct stem cell protection and regeneration.

Hematopoietic Stem Cell Shielding

Research published in the Journal of Ginseng Research and related publications demonstrates that ginseng pretreatment enhanced survival in irradiated animals by shielding hematopoietic stem cells (HSCs), the progenitor cells responsible for regeneration and recovery of the blood-forming system. Specifically, irradiated animals pretreated with ginseng extract showed increased colony-forming units in the spleen (CFU-S) and spleen weight, with subsequent increases in peripheral blood cell counts. An acidic polysaccharide fraction of Panax ginseng (APG) has been shown to significantly enhance the number of bone marrow cells and spleen cells in irradiated mice through immunomodulatory rather than purely antioxidant activity.

Joo HG, Kim HJ, Kim MH, Byon YY, Park JW, Jee Y. (2007). Radioprotective effects of an acidic polysaccharide of Panax ginseng on bone marrow cells. J Vet Sci. 8(1):39-44.

Ginsenoside Rg1 and Intestinal Stem Cell Regeneration

A particularly elegant line of research has demonstrated that ginsenoside Rg1, a specific saponin from ginseng, enhances the paracrine effects of bone marrow-derived mesenchymal stem cells on radiation-induced intestinal injury. The mechanism involves increased secretion of VEGF (vascular endothelial growth factor) and IL-6, mediated through a heme oxygenase-1 (HO-1) dependent pathway. The Rg1-enhanced conditioned medium improved survival and promoted structural and functional restoration of irradiated intestinal tissue through regulation of intestinal regeneration, inflammation, and angiogenesis—a cell-free therapeutic approach distinct from antioxidant activity.

Luo Y, Wang B, Liu J, et al. (2020). Ginsenoside RG1 enhances the paracrine effects of bone marrow-derived mesenchymal stem cells on radiation induced intestinal injury. Aging (Albany NY). 13(1):1132-1152. doi:10.18632/aging.202241.

Notch and Wnt Signaling Activation

A 2025 study published in the Journal of Ethnopharmacology revealed that ginseng extract and total ginsenosides protect hematopoietic stem cell function by activating the Notch and Wnt signaling pathways. These developmental signaling cascades regulate stem cell self-renewal, proliferation, and differentiation—critical processes for recovery from radiation-induced hematopoietic injury. Individual ginsenosides demonstrate specific activities: Rg1 alleviates HSC senescence via Wnt signaling; Rg3 enhances proliferation and prevents mesenchymal stem cell senescence through calcium signaling; and the collective ginsenoside profile participates in maintaining the balance between proliferation and differentiation.

Gao X, Qian B, Yuan T, et al. (2025). Ginseng extract and total ginsenosides protect the function of hematopoietic stem cells by activating the Notch and Wnt signal pathways. J Ethnopharmacol. 347:119798.

3. Curcumin (Curcuma longa): NF-κB Modulation and Selective Radioprotection

Curcumin, the principal polyphenol from turmeric, has been extensively studied for its dual capacity as both a radiosensitizer of cancer cells and a radioprotector of normal cells. While curcumin does exhibit antioxidant properties, its most clinically significant radioprotective mechanisms operate through anti-inflammatory and signaling pathway modulation.

NF-κB Pathway Suppression

Curcumin’s central radioprotective mechanism involves modulation of the nuclear factor kappa-B (NF-κB) signaling pathway. NF-κB is a master transcription factor that controls the expression of genes involved in inflammation, immune responses, and cell survival. Ionizing radiation markedly enhances NF-κB DNA-binding activity, driving a pro-inflammatory cascade that contributes significantly to normal tissue damage. Curcumin pretreatment significantly suppresses radiation-induced NF-κB activation, thereby reducing downstream inflammatory mediator production, cytokine release, and tissue fibrosis.

Cell Cycle–Dependent Protection

Research using curcumin nanolipoprotein particles (cNLPs) has revealed a fascinating cell cycle–dependent mechanism of radioprotection. Quiescent (G0/G1-phase) normal cells showed improved survival following irradiation when pretreated with curcumin, while actively dividing cell populations (such as tumors) experienced radiosensitization. This selectivity arises not from antioxidant chemistry but from curcumin’s differential effects on cell cycle checkpoints and DNA damage response pathways in resting versus proliferating cells.

Evans AC, Martin KA, Saxena M, et al. (2022). Curcumin Nanodiscs Improve Solubility and Serve as Radiological Protectants against Ionizing Radiation Exposures in a Cell-Cycle Dependent Manner. Nanomaterials. 12(20):3619. doi:10.3390/nano12203619.

Anti-Inflammatory and Anti-Fibrotic Effects

Multiple in vivo and in vitro studies have confirmed that curcumin reduces radiation-induced inflammation, angiogenesis, tumor growth, and metastasis through NF-κB pathway modulation. This anti-inflammatory mechanism protects normal tissues from the chronic inflammatory cascade that contributes to radiation fibrosis, mucositis, and dermatitis—three of the most common dose-limiting side effects of radiation therapy.

Zoi V, Galani V, Tsekeris P, et al. (2022). Radiosensitization and Radioprotection by Curcumin in Glioblastoma and Other Cancers. Biomedicines. 10(2):312. [Review of NF-κB–mediated mechanisms].

4. Holy Basil / Tulsi (Ocimum sanctum): Selective Normal Tissue Protection and DNA Damage Prevention

Tulsi, one of the most sacred herbs of the Ayurvedic tradition, has accumulated a substantial evidence base for radioprotection that extends well beyond its known antioxidant properties.

Selective Tissue Protection

The aqueous extract of tulsi and its flavonoids, orientin and vicenin, have been shown to protect mice against gamma-radiation-induced sickness and mortality while selectively protecting normal tissues against the tumoricidal effects of radiation. This selectivity—protecting normal cells without interfering with radiation’s ability to kill tumor cells—suggests mechanisms beyond simple free-radical scavenging, including differential effects on apoptotic thresholds between normal and malignant cells.

Immunomodulatory and Anti-Inflammatory Mechanisms

Preclinical studies have demonstrated that holy basil extracts enhance both humoral (antibody-mediated) and cell-mediated immune responses, including increased antibody production and enhanced macrophage phagocytic activity. Eugenol, the primary bioactive compound in tulsi, inhibits cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX), enzymes responsible for the production of pro-inflammatory prostaglandins and leukotrienes. This anti-inflammatory activity is mechanistically distinct from antioxidant scavenging and addresses the sustained inflammatory response that drives late radiation toxicity.

Phytochemical-Mediated DNA Protection

Key phytochemicals in tulsi—including eugenol, rosmarinic acid, apigenin, and carnosic acid—have been shown to prevent radiation-induced DNA damage through mechanisms that involve modulation of DNA repair gene expression and inhibition of protein kinase C (PKC) and mitogen-activated protein kinase (MAPK) signaling rather than direct radical neutralization. A notable clinical reference includes the study examining tulsi as a radioprotector in head and neck cancer clients undergoing radiation therapy.

Baliga MS et al. (2016). Radioprotective effects of the Ayurvedic medicinal plant Ocimum sanctum Linn. (holy basil): A memoir. J Cancer Res Ther. 12:20-27.

Biomedicine (2012). Tulsi (Ocimum sanctum) as radioprotector in head and neck cancer patients undergoing radiation therapy. 32:39-44.

5. Astragalus (Astragalus membranaceus): Telomerase Activation and Stem Cell Regeneration

Astragalus, a cornerstone of traditional Chinese medicine, offers a uniquely compelling radioprotective profile centered on mechanisms that are fundamentally distinct from antioxidant activity.

Telomerase Activation and Cellular Longevity

The bioactive saponins unique to Astragalus—astragalosides I through IV and their hydrolysis product cycloastragenol (the basis for the commercial compound TA-65)—have been associated with telomerase activation and telomere maintenance. A 2025 review in Biomolecules confirmed that these compounds promote cellular longevity, improve tissue function, and reduce senescence through telomerase-related pathways. In the context of radiation injury, where accelerated cellular senescence contributes significantly to late toxicity in normal tissues, this telomere-protective mechanism represents a fundamentally different approach to radioprotection.

Astragalus membranaceus Has Potential Anti-Aging and Anticancer Effects on Skin and Bone. Biomolecules. 2026;16(6):864. doi:10.3390/biom16060864.

HIF-1 Signaling and Intestinal Stem Cell Regeneration

Astragalus polysaccharide (APS) has been shown to promote the regeneration of intestinal stem cells through the hypoxia-inducible factor-1 (HIF-1) signaling pathway. Published in Cell Proliferation, this research demonstrated that APS could promote intestinal stem cell survival and regeneration after high-dose ionizing radiation through HIF-1 pathway activation—a mechanism that targets the stem cell niche directly rather than scavenging reactive oxygen species. Given that gastrointestinal toxicity is among the most debilitating side effects of abdominal and pelvic radiation therapy, this intestinal stem cell–protective mechanism has significant clinical implications.

Ding Q, Zu X, Chen W, et al. (2024). Astragalus polysaccharide promotes the regeneration of intestinal stem cells through HIF-1 signalling pathway. J Cell Mol Med. 28(3):e18058. doi:10.1111/jcmm.18058.

Immune Senescence Reversal

Clinical data has shown that TA-65 (derived from cycloastragenol) significantly enhanced telomerase activity in immune cells over one year of treatment, resulting in reduced systemic inflammatory markers (IL-6 and TNF-α), improved lymphocyte proliferation, and decreased signs of immune senescence. For clients undergoing radiation therapy, where treatment-induced immune suppression and accelerated immune aging are common, this mechanism of restoring immune competence through telomerase activation offers a fundamentally different therapeutic approach.

6. Ginkgo biloba: Clastogenic Factor Neutralization and TGF-β3 Modulation

Ginkgo biloba extract (EGb 761) has been studied for radioprotection since the pioneering work with Chernobyl recovery workers, and while its superoxide-scavenging properties are well-documented, several distinct non-antioxidant mechanisms merit attention.

Clastogenic Factor Neutralization

Clastogenic factors (CFs) are chromosome-damaging substances found in the blood of irradiated individuals that can persist for years and cause ongoing genetic instability. CFs were first described in the blood of persons irradiated accidentally or therapeutically and were detected in a high percentage of Chernobyl accident recovery workers. Research published in Free Radical Biology and Medicine demonstrated that EGb 761 effectively neutralized clastogenic factor–induced chromosome damage in blood cultures. While part of this effect may relate to superoxide scavenging, the neutralization of transmissible clastogenic factors represents a distinct mechanism of preventing bystander-effect–mediated radiation damage—a secondary wave of injury that extends beyond the directly irradiated field.

Emerit I et al. (1995). Radiation-induced clastogenic factors: anticlastogenic effect of Ginkgo biloba extract. Free Radic Biol Med. 18(6):985-91.

Emerit I et al. (1995). Clastogenic factors in the plasma of Chernobyl accident recovery workers: anticlastogenic effect of Ginkgo biloba extract.

TGF-β3 and Anti-Fibrotic Signaling

In experimental radiation dermatitis models, ginkgo biloba extract modulated the expression of transforming growth factor-beta 3 (TGF-β3) and proliferating cellular nuclear antigen (PCNA). TGF-β3 plays critical roles in cell cycle regulation, immunoregulation, and anti-fibrogenesis. Its upregulation by ginkgo extract suggests a radioprotective mechanism that involves tissue remodeling signaling rather than free-radical chemistry, with particular relevance to preventing late radiation fibrosis in skin and other tissues.

Yirmibesoglu E et al. (2012). The protective effects of Ginkgo biloba extract (EGb-761) on radiation-induced dermatitis: an experimental study. Clin Exp Dermatol. 37:387-394.

7. Soy Isoflavones (Genistein/Daidzein): Immune Cell Modulation and Selective Radioprotection with Clinical Data

Soy isoflavones, particularly genistein, represent one of the best-studied natural radioprotective compounds and possess the most robust clinical evidence for non-antioxidant radioprotective mechanisms.

Macrophage and Neutrophil Modulation

Research published in multiple journals including Frontiers in Oncology has demonstrated that soy isoflavones promote radioprotection of normal lung tissue specifically through inhibition of radiation-induced activation of macrophages and neutrophils. The mechanism involves reduction of infiltration and activation of alveolar macrophages and neutrophils in both bronchoalveolar and lung parenchyma compartments. Critically, soy isoflavones protected F4/80+CD11c− interstitial macrophages—cells known to play an immunoregulatory role that are depleted by radiation. This is a cell type–specific immunomodulatory effect, not an antioxidant phenomenon.

Abernathy LM, Fountain MD, Rothstein SE, et al. (2015). Soy Isoflavones Promote Radioprotection of Normal Lung Tissue by Inhibition of Radiation-Induced Activation of Macrophages and Neutrophils. J Thorac Oncol. 10(12):1703-1712.

Innate Immune Pathway Modulation (MDSCs)

Soy isoflavones modulate myeloid-derived suppressor cells (MDSCs) in irradiated lung tissue. Radiation decreases CD11b+ cells expressing arginase-1 (Arg-1) in lung tissue, but concurrent soy isoflavone administration maintained these populations. Arginase-1 expression was predominantly found in granulocytic MDSCs (gr-MDSCs), and soy isoflavones preserved this immunomodulatory cell population through NF-κB pathway effects—a mechanism of immune system preservation fundamentally different from radical scavenging.

Abernathy LM, Fountain MD, Joiner MC, Hillman GG. (2017). Innate Immune Pathways Associated with Lung Radioprotection by Soy Isoflavones. Front Oncol. 7:7. doi:10.3389/fonc.2017.00007.

Clinical Trial Evidence

Soy isoflavones are among the few natural radioprotective agents with clinical trial data. In a trial of prostate cancer clients receiving radiation therapy, soy isoflavone supplementation taken in conjunction with radiotherapy reduced radiation toxicity and resulted in improved urinary, gastrointestinal, and sexual function outcomes. Across 18 years of research, studies in prostate cancer, renal cell carcinoma, and non-small cell lung cancer models have consistently demonstrated that soy isoflavones simultaneously radiosensitize tumors while protecting normal tissues—a dual capability with profound clinical implications. The safety profile of soy isoflavones has been confirmed in multiple controlled clinical trials, distinguishing them from synthetic radioprotectors like amifostine, which cause significant nausea and vomiting.

Ahmad IU, Forman JD, Sarkar FH, et al. (2010). Soy Isoflavones in Conjunction with Radiation Therapy in Patients with Prostate Cancer. Nutr Cancer. 62(7):996-1000.

Hillman GG. (2019). Soy Isoflavones Protect Normal Tissues While Enhancing Radiation Responses. Semin Radiat Oncol. 29(1):62-71.

8. Medicinal Mushrooms: Beta-Glucan Immune Activation and DNA Repair

Medicinal mushrooms offer a category of radioprotective support that operates primarily through immune modulation rather than antioxidant chemistry, making them particularly relevant for clients whose radiation therapy regimens include hematologic or immunologic toxicity.

Reishi (Ganoderma lucidum): Beta-Glucan Radioprotection

Beta-glucan isolated from reishi mushroom has been shown to significantly improve mouse survival after radiation exposure. In preclinical studies, beta-glucan rescued 66% of mice from lethal radiation doses, compared to 100% mortality in unprotected controls. When combined with the conventional radioprotective drug amifostine, survival increased further to 83%. Triterpenes from reishi have demonstrated the ability to prevent membrane damage and reduce DNA strand breaks in human peripheral blood lymphocytes, while polysaccharides from reishi enhance the DNA strand break repair process in human cells—a direct DNA repair mechanism distinct from antioxidant activity.

Pillai TG, Uma Devi P. (2013). Mushroom beta glucan: potential candidate for post irradiation protection. Mutat Res. 751(2):109-115. doi:10.1016/j.mrgentox.2012.12.005.

Turkey Tail (Trametes versicolor): NF-κB Inhibition and Immune Recovery

Turkey tail mushroom contains polysaccharide-K (PSK) and polysaccharide-peptide (PSP), protein-bound polysaccharides with powerful immune-enhancing effects. PSK has been shown to inhibit NF-κB and survivin (an anti-apoptotic molecule), facilitating selective apoptosis of cancer cells while preserving normal tissue. Clinical evidence, including studies reviewed by the National Cancer Institute, demonstrates that turkey tail compounds boost CD69 expression on monocytes and lymphocytes, thereby increasing natural killer (NK) cell activity. A meta-analysis demonstrated increased survival rates for cancer clients who took turkey tail, particularly those with breast, gastric, and colorectal cancers undergoing conventional treatments including radiation. In China, reishi is actively used to strengthen the immune system of cancer clients receiving chemotherapy or radiation therapy.

Eliza WL et al. Meta-analysis of turkey tail (PSK/PSP) demonstrating increased survival in cancer patients. [Breast, gastric, colorectal cancers].

NCI PDQ: Medicinal Mushrooms. cancer.gov. [Reviewed evidence on immune effects].

Clinical Synthesis: A Framework for Non-Antioxidant Radioprotection

The evidence reviewed in this article reveals at least six distinct non-antioxidant mechanisms through which herbs and natural compounds protect normal tissues during radiation therapy:

DNA Repair Enhancement: Reishi polysaccharides enhance strand break repair; tulsi phytochemicals modulate DNA repair gene expression; ginseng ginsenosides support genomic stability through stem cell signaling.

Anti-Apoptotic Signaling: Ashwagandha modulates the Bcl-2/Bax ratio and caspase cascades; curcumin differentially affects apoptotic thresholds based on cell cycle phase; genistein reduces apoptosis in normal mucosal tissues.

Immune System Modulation: Soy isoflavones preserve immunoregulatory macrophages and modulate MDSCs; turkey tail activates NK cells and boosts CD69 expression; ashwagandha prevents myelosuppression; tulsi enhances humoral and cell-mediated immunity.

Stem Cell Regeneration: Ginseng protects hematopoietic stem cells through Notch and Wnt signaling; astragalus promotes intestinal stem cell regeneration through HIF-1; ginseng Rg1 enhances mesenchymal stem cell paracrine effects.

Anti-Inflammatory Pathway Modulation: Curcumin and soy isoflavones suppress NF-κB; tulsi inhibits COX-2 and 5-LOX; ashwagandha reduces inflammatory cytokine cascades; turkey tail modulates NF-κB and survivin.

Telomere and Senescence Protection: Astragalus activates telomerase and maintains telomere length; ginkgo biloba neutralizes clastogenic factors that perpetuate genetic instability.

These mechanisms are not mutually exclusive, and most of the herbs discussed exhibit multiple non-antioxidant pathways simultaneously. This mechanistic redundancy and pleiotropy is, in fact, one of the key advantages of botanical radioprotection over single-target synthetic agents.

Important Considerations for Integrative Practice

While the preclinical evidence is compelling, several important caveats apply to the clinical application of these findings. The majority of studies reviewed are preclinical (in vitro or animal models), and robust randomized controlled trial data in human radiation therapy populations remains limited, with soy isoflavones being a notable exception. Timing of administration relative to radiation fractions may be critical—some compounds may need to be given before radiation (radioprotectors) while others show benefit when given after (radiomitigators). Dose-response relationships are not always linear, and optimal dosing for radioprotection may differ from dosing for other indications. Potential interactions between herbal radioprotective agents and concurrent chemotherapy or targeted therapy regimens must be carefully evaluated. Communication and coordination with the radiation oncology team is essential when incorporating any supplemental strategy during active treatment.

Clients interested in incorporating any of these approaches during radiation therapy should work with a physician experienced in integrative oncology who can evaluate the totality of their treatment protocol, individual risk factors, and the evolving evidence base. For a comprehensive, individualized integrative oncology consultation, visit www.directintegrativecare.com.

References

1. Abdel-Hamid GR, ElBakary NM, Abdel-Rafei MK, Thabet NM, Azab KS, Maarouf RE. Ashwagandha Alter the Apoptotic Mediated Inflammatory Determinants in Sera of γ-Irradiated Rats. Natural Product Communications. 2025. doi:10.1177/1934578X251346332.

2. Uma Devi P, Akagi K, Ostapenko V, Tanaka Y, Sugahara T. Withaferin A: a new radiosensitizer from the Indian medicinal plant Withania somnifera. Int J Radiat Biol. 1996;69(2):193-197.

3. Kalthur G, Pathirissery UD. Enhancement of the response of B16F1 melanoma to fractionated radiotherapy and prolongation of survival by withaferin A and/or hyperthermia. Integr Cancer Ther. 2010;9(4):370-377. doi:10.1177/1534735410378664.

4. Joo HG, Kim HJ, Kim MH, Byon YY, Park JW, Jee Y. Radioprotective effects of an acidic polysaccharide of Panax ginseng on bone marrow cells. J Vet Sci. 2007;8(1):39-44. doi:10.4142/jvs.2007.8.1.39.

5. Luo Y, Wang B, Liu J, Ma F, Luo D, Zheng Z, Lu Q, Zhou W, Zheng Y, Zhang C, Wang Q, Sha W, Chen H. Ginsenoside RG1 enhances the paracrine effects of bone marrow-derived mesenchymal stem cells on radiation induced intestinal injury. Aging (Albany NY). 2020;13(1):1132-1152. doi:10.18632/aging.202241.

6. Gao X, Qian B, Yuan T, Pan D, Liang Z, Yin Y, Liu S, Li X, Zhao D, Zhang H. Ginseng extract and total ginsenosides protect the function of hematopoietic stem cells by activating the Notch and Wnt signal pathways. J Ethnopharmacol. 2025;347:119798.

7. Evans AC, Martin KA, Saxena M, Bicher S, Wheeler E, Cordova EJ, Porada CD, Almeida-Porada G, Kato TA, Wilson PF, Coleman MA. Curcumin Nanodiscs Improve Solubility and Serve as Radiological Protectants against Ionizing Radiation Exposures in a Cell-Cycle Dependent Manner. Nanomaterials. 2022;12(20):3619. doi:10.3390/nano12203619.

8. Zoi V, Galani V, Tsekeris P, Kyritsis AP, Alexiou GA. Radiosensitization and Radioprotection by Curcumin in Glioblastoma and Other Cancers. Biomedicines. 2022;10(2):312. doi:10.3390/biomedicines10020312.

9. Baliga MS, Rao S, Rai MP, D'souza P. Radio protective effects of the Ayurvedic medicinal plant Ocimum sanctum Linn. (Holy Basil): A memoir. J Cancer Res Ther. 2016;12(1):20-27. doi:10.4103/0973-1482.151422.

10. Reshma K, Kamalaksh S, Bindu YS, Pramod K, Asfa A, Amritha D, Aswathi S, Chandrashekar R. Tulasi (Ocimum Sanctum) as radioprotector in head and neck cancer patients undergoing radiation therapy. Biomedicine. 2012;32(1):39-44.

11. Ding Q, Zu X, Chen W, Xin J, Xu X, Lv Y, Wei X, Wang J, Wei Y, Li Z, Cai J, Du J, Zhang W. Astragalus polysaccharide promotes the regeneration of intestinal stem cells through HIF-1 signalling pathway. J Cell Mol Med. 2024;28(3):e18058. doi:10.1111/jcmm.18058.

12. Abdelrahman ZR, Harb AA, Abdalla SS. Astragalus membranaceus Has Potential Anti-Aging and Anticancer Effects on Skin and Bone. Biomolecules. 2026;16(6):864. doi:10.3390/biom16060864.

13. Emerit I, Arutyunyan R, Oganesian N, Levy A, Cernjavsky L, Sarkisian T, Pogossian A, Asrian K. Radiation-induced clastogenic factors: anticlastogenic effect of Ginkgo biloba extract. Free Radic Biol Med. 1995;18(6):985-991. doi:10.1016/0891-5849(94)00220-e.

14. Yirmibesoglu E, Karahacioglu E, Kilic D, Lortlar N, Akbulut G, Omeroglu S. The protective effects of Ginkgo biloba extract (EGb-761) on radiation-induced dermatitis: an experimental study. Clin Exp Dermatol. 2012;37(4):387-394. doi:10.1111/j.1365-2230.2011.04253.x.

15. Abernathy LM, Fountain MD, Rothstein SE, David JM, Yunker CK, Rakowski J, Lonardo F, Joiner MC, Hillman GG. Soy Isoflavones Promote Radioprotection of Normal Lung Tissue by Inhibition of Radiation-Induced Activation of Macrophages and Neutrophils. J Thorac Oncol. 2015;10(12):1703-1712.

16. Abernathy LM, Fountain MD, Joiner MC, Hillman GG. Innate Immune Pathways Associated with Lung Radioprotection by Soy Isoflavones. Front Oncol. 2017;7:7. doi:10.3389/fonc.2017.00007.

17. Ahmad IU, Forman JD, Sarkar FH, Hillman GG, Heath E, Vaishampayan U, Cher ML, Andic F, Rossi PJ, Kucuk O. Soy Isoflavones in Conjunction with Radiation Therapy in Patients with Prostate Cancer. Nutr Cancer. 2010;62(7):996-1000.

18. Hillman GG. Soy Isoflavones Protect Normal Tissues While Enhancing Radiation Responses. Semin Radiat Oncol. 2019;29(1):62-71. doi:10.1016/j.semradonc.2018.10.002.

19. Pillai TG, Uma Devi P. Mushroom beta glucan: potential candidate for post irradiation protection. Mutat Res. 2013;751(2):109-115. doi:10.1016/j.mrgentox.2012.12.005.

20. Eliza WL, Fai CK, Chung LP. Efficacy of Yun Zhi (Coriolus versicolor) on survival in cancer patients: systematic review and meta-analysis. Recent Pat Inflamm Allergy Drug Discov. 2012;6(1):78-87. doi:10.2174/187221312798889310.

21. National Cancer Institute. Medicinal Mushrooms (PDQ®)–Health Professional Version. Bethesda, MD: National Cancer Institute. Available at: https://www.cancer.gov/about-cancer/treatment/cam/hp/mushrooms-pdq.

About Dr. Kim

Dr. Yoon Hang "John" Kim is board-certified in Preventive Medicine, with additional certifications in Medical Acupuncture (UCLA) and Integrative & Holistic Medicine. With over 20 years of experience in integrative and functional medicine, he completed his fellowship training under Dr. Andrew Weil at the University of Arizona as an Osher Fellow and holds IFM Scholar status. Dr. Kim specializes in low-dose naltrexone (LDN), autoimmune conditions, chronic pain, integrative oncology, fibromyalgia, chronic fatigue syndrome, mast cell activation syndrome (MCAS), and mold toxicity. He is the author of three books and more than 20 published articles, and founded the LDN Support Group, an international community of over 9,000 members.

Professional: www.yoonhangkim.com

Clinical Practice: www.directintegrativecare.com