Synergistic Combination of Quercetin and Mafosfamide in Treatment of Bladder Cancer Cells.
Interestingly, the synergistic effect was observed only when cells were pre-treated with MFA for 24 h before adding quercetin, not in the reverse order.
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CARE DELIVERED AT SUNRIDGE
Explore care for cancer, chronic conditions and health optimization, plus treatments and services at our Scottsdale clinic.
✓ Physicians & nurses onsite
✓ Dedicated infusion rooms
✓ Individualized treatment plans
Start with what you are facing.
Active care selected for a clinical reason.
Know what happens before you arrive.
ADDITIONAL SERVICES
PHYSICIAN-DIRECTED CANCER CARE
Explore cancer care, find information for your diagnosis and plan your next step with our Scottsdale team.
Understand your next step.
Find information by cancer type.
Plan active care in Scottsdale.
SUNRIDGE MEDICAL • INTEGRATIVE ONCOLOGY
Dose, formulation, kidney function, medications and the clinical goal matter. We can review the product and cancer-treatment schedule before a physician consultation.
Share your diagnosis, current treatment and the quercetin product you are considering.
Quercetin and cancer research has become a major area of natural-compound oncology because this plant flavonoid can influence apoptosis, inflammation, angiogenesis, PI3K/AKT/mTOR signaling, NF-κB activity, STAT3 signaling, oxidative stress and tumor-cell migration in laboratory models.
Quercetin is a flavonol found in foods such as onions, apples, capers, berries, citrus peel and many medicinal plants. It is widely studied for its antioxidant, anti-inflammatory and cell-signaling effects.
At Sunridge Medical in Scottsdale, Arizona, quercetin may be considered as part of a physician-directed integrative cancer treatment program when appropriate for the individual patient.
This page is designed as a deeper research hub that can be linked from our lung cancer, cholangiocarcinoma, prostate cancer, pancreatic cancer and other cancer pages where quercetin-related mechanisms may be relevant.
PLANT FLAVONOID • CANCER BIOLOGY
Quercetin is a plant flavonoid being studied for multiple cancer-related signaling effects.
Quercetin is a naturally occurring flavonoid found in many fruits, vegetables and botanicals. It is especially associated with onions, apples, capers, berries, citrus peel, tea and several medicinal plants.
In cancer research, quercetin is most often discussed as a multi-target natural compound. Rather than acting on a single receptor or one isolated pathway, quercetin has been studied for effects across numerous signaling networks that influence tumor behavior.
Reviews of the anticancer literature describe quercetin as affecting apoptosis, proliferation, inflammation, angiogenesis, invasion, metastasis, autophagy, PI3K/AKT/mTOR signaling, MAPK pathways, NF-κB, STAT3 and oxidative-stress biology.12
That breadth is scientifically interesting, but it also requires careful interpretation. Laboratory findings do not automatically mean quercetin is an established cancer treatment. Human cancer data remain limited compared with the preclinical literature.
FOOD SOURCE VS THERAPEUTIC COMPOUND
Quercetin can be consumed through food, but food intake and therapeutic use are not the same.
This distinction matters because quercetin has poor oral bioavailability in many conventional formulations. Delivery strategy can influence blood levels and biological effects.
MULTI-PATHWAY BIOLOGY
One reason quercetin and cancer research continues to grow is that the compound has been studied across multiple mechanisms relevant to cancer development and progression.
Depending on the cancer model, quercetin has been reported to influence:
This is why quercetin is often described as a pleiotropic or multi-target flavonoid.
APOPTOSIS AND CELL CYCLE
Apoptosis is the programmed process through which abnormal or damaged cells are eliminated. Many cancer cells acquire the ability to evade apoptosis, allowing them to survive despite stress, DNA damage or therapy.
A broad review of quercetin’s anticancer potential describes direct pro-apoptotic effects in tumor cells across many in vitro and in vivo models.1
Experimental studies have reported quercetin-associated changes in caspase activation, mitochondrial signaling, Bcl-2 family proteins, cell-cycle regulators and survival pathways. In some models, quercetin induces cell-cycle arrest before apoptosis, limiting the ability of malignant cells to continue dividing.
These findings support the biological plausibility of quercetin as an integrative oncology compound, but the strength of evidence remains much greater in laboratory systems than in definitive human cancer outcomes.
INFLAMMATION AND NF-ΚB
Chronic inflammatory signaling can support cancer progression by influencing tumor-cell survival, angiogenesis, invasion, immune evasion and metastatic behavior.
Quercetin has been studied for its ability to modulate inflammatory pathways, including NF-κB, one of the central transcription factors involved in inflammation and cell survival.
This becomes particularly relevant when discussing cancers such as cholangiocarcinoma, pancreatic cancer, lung cancer, colorectal cancer and prostate cancer, where inflammatory and survival pathways can influence tumor behavior.
The anti-inflammatory aspect of quercetin is not a generic wellness claim; it reflects specific pathway-level research that may be relevant when evaluating a broader integrative oncology strategy.
ANGIOGENESIS AND INVASION
To grow beyond a small size, tumors require blood-vessel support. To spread, they must acquire invasive and migratory behavior. Quercetin has been studied in relation to both angiogenesis and metastatic signaling.
Reviews and experimental studies describe quercetin effects on VEGF-related pathways, matrix metalloproteinases, epithelial-mesenchymal transition and other mechanisms that may influence tumor invasion and migration.2
This makes quercetin biologically interesting for cancers in which invasion and spread are major clinical concerns, including lung cancer, pancreatic cancer, cholangiocarcinoma, breast cancer and prostate cancer.
Onions, apples, capers and citrus peel are among dietary sources associated with quercetin.
CANCER-SPECIFIC RESEARCH
Cholangiocarcinoma is a particularly important cancer to include because quercetin has been studied directly in bile-duct cancer models.
A 2014 study reported that quercetin and EGCG exerted chemopreventive effects in cholangiocarcinoma cells through suppression of the JAK/STAT signaling pathway.3
A 2023 study focused on intrahepatic cholangiocarcinoma found that quercetin inhibited tumor behavior by inducing ferroptosis and inhibiting invasion via the NF-κB pathway.4
These are not definitive human treatment trials, but they are highly relevant for building an internal link from the Sunridge cholangiocarcinoma page to this quercetin research page. They connect quercetin to cholangiocarcinoma-specific pathways rather than only to generic cancer biology.
LUNG CANCER RESEARCH
Quercetin has been studied in non-small cell lung cancer models, including research involving apoptosis, DNA-damage response, PI3K/AKT signaling and EGFR-related biology.
A 2023 study reported that quercetin inhibited DNA-damage responses and induced apoptosis through the SIRT5/PI3K/AKT pathway in non-small cell lung cancer.5
Other reviews of quercetin in lung-cancer biology describe potential activity involving kinase signaling, EGFR-related pathways, oxidative stress and cancer-cell survival.6
This makes the page useful as a supporting resource for a Sunridge lung cancer page, especially in sections discussing physician-directed botanical medicine, oxidative signaling and molecular pathway support.
PROSTATE CANCER RESEARCH
Quercetin has been studied extensively in prostate-cancer laboratory and animal models.
A prostate-cancer review concluded that in vitro and in vivo studies have shown quercetin can inhibit prostate-cancer processes through multiple mechanisms.7
More recent experimental work reported that quercetin affected cell-survival pathways in prostate cancer and has also been studied for effects on docetaxel resistance in prostate-cancer models.89
In an integrative oncology context, this evidence supports further research into quercetin as a pathway-focused compound, but it does not make quercetin a replacement for prostate-cancer therapies such as surgery, radiation, androgen-deprivation therapy, targeted agents or other physician-directed treatments.
PANCREATIC CANCER RESEARCH
Pancreatic cancer is another area where quercetin has been studied in laboratory and animal models.
A pancreatic-cancer study reported that quercetin inhibited the growth of pancreatic cancer cell lines, induced apoptosis and reduced tumor growth in experimental models.10
Additional research has examined quercetin’s ability to sensitize TRAIL-resistant pancreatic cancer cells to apoptosis through JNK-mediated cFLIP turnover.11
These findings are mechanistically important because pancreatic cancer often displays resistance to apoptosis and aggressive survival signaling. The evidence, however, remains primarily preclinical.
BREAST CANCER RESEARCH
Quercetin has been studied in breast cancer models involving apoptosis, STAT3, PI3K/AKT/mTOR signaling, migration, cancer stem-like cells and drug-resistance mechanisms.
In HER2-overexpressing breast-cancer cells, quercetin induced caspase-dependent extrinsic apoptosis through inhibition of STAT3 signaling.12
Other studies have reported that quercetin suppresses breast cancer stem-like cells through PI3K/AKT/mTOR inhibition.13
These findings make quercetin a serious topic in breast-cancer natural-compound research, but the clinical evidence remains far less developed than the laboratory literature.
OVARIAN CANCER RESEARCH
Ovarian cancer research has examined quercetin in relation to apoptosis, cell-cycle regulation, migration, invasion, chemotherapy sensitivity and drug-delivery systems.
Experimental work has shown quercetin-induced apoptosis of human ovarian carcinoma cells through microRNA-145-related mechanisms.14
A review of quercetin in ovarian cancer described evidence for effects on proliferation, apoptosis, cell-cycle progression and combination strategies involving agents such as cisplatin.15
More recent work has also examined quercetin combined with paclitaxel in ovarian-cancer cells, reporting effects on apoptosis, invasion and migration.16
COLON AND BLOOD CANCER RESEARCH
Quercetin has also been studied across colorectal cancer, leukemia, lymphoma and multiple myeloma models.
A review of quercetin in blood, prostate, skin, lung, breast and colon cancers summarized multiple mechanisms including regulation of apoptosis, proliferation, migration, invasion and signaling pathways.17
In colorectal cancer models, quercetin has been investigated for effects on Wnt/β-catenin signaling, PI3K/AKT, apoptosis and cell-cycle regulation.
In blood cancers, laboratory research has examined effects on leukemia and lymphoma cell survival, apoptosis and inflammatory signaling. Human cancer evidence remains limited, but the breadth of preclinical work is substantial.
LIVER CANCER RESEARCH
Because quercetin is metabolized in part through the liver, liver cancer and liver function deserve separate attention.
Reviews of hepatocellular carcinoma research describe quercetin effects on apoptosis, inflammation, migration, angiogenesis and signaling pathways relevant to liver-cancer progression.18
Animal and laboratory models have also explored quercetin as an adjunctive compound in liver-cancer research. From a clinical perspective, however, liver function and drug metabolism must be considered carefully before using concentrated quercetin in patients with liver involvement or active chemotherapy.
HUMAN CANCER EVIDENCE
The preclinical literature on quercetin and cancer is extensive. Human cancer evidence is much more limited.
This distinction is important for a medically credible integrative oncology page. Quercetin has compelling pathway-level research, but it has not been established as a stand-alone cancer treatment in large randomized clinical trials.
Published clinical research has included small studies and trials in cancer-related contexts, but the strongest evidence for quercetin remains mechanistic, preclinical and formulation-focused. That is why physician-directed use should be presented as part of a broader integrative strategy rather than as a proven replacement for oncology care.
BIOAVAILABILITY AND DELIVERY
One of the biggest obstacles in quercetin research is bioavailability.
Quercetin can have limited water solubility, variable absorption and extensive metabolism. This means that promising effects seen in cell cultures may not translate directly to human tissue exposure after ordinary oral dosing.
For this reason, researchers have studied delivery systems such as nanoparticles, liposomes, nanoemulsions, phytosomes, glycosides and other quercetin derivatives to improve stability, absorption and tumor delivery.19
For integrative oncology, formulation is not a minor detail. It may influence dosing, blood levels, tissue exposure and the ability to combine quercetin with other therapies.
COMBINATION STRATEGIES
Some of the most interesting quercetin research involves combination strategies.
Quercetin has been studied with chemotherapy agents, targeted therapies, TRAIL, paclitaxel, cisplatin and docetaxel in different tumor models. These studies often examine whether quercetin can alter apoptosis, oxidative stress, drug resistance, transporter expression or survival signaling.
In pancreatic cancer, quercetin has been reported to sensitize TRAIL-resistant cells to apoptosis.11 In prostate cancer models, quercetin has been studied for reversal of docetaxel resistance.9 In ovarian cancer models, quercetin plus paclitaxel has been studied for effects on apoptosis, invasion and migration.16
These findings do not mean patients should combine quercetin with chemotherapy on their own. Combination strategies require medical oversight because natural compounds may also alter drug metabolism, toxicity or therapeutic effect.
DRUG INTERACTIONS AND SAFETY
Quercetin is pharmacologically active and can affect enzymes, transporters and signaling pathways. This is part of what makes it interesting, but it is also why medical supervision matters.
Memorial Sloan Kettering notes that quercetin showed antioxidant, anti-inflammatory and chemopreventive effects in laboratory studies, while also cautioning that it can act as an anti-apoptotic agent in some settings and may interact with drugs.20
Potential areas to review before physician-directed use include:
The same biological activity that makes quercetin useful to study also makes it inappropriate to treat as a harmless generic supplement in every cancer case.
SUNRIDGE MEDICAL
At Sunridge Medical, quercetin may be considered as one part of a broader integrative oncology strategy.
The decision depends on the clinical context, including:
Quercetin is best understood as a pathway-focused natural compound rather than a single-purpose cancer drug. It may be most useful when selected deliberately and integrated into a larger plan that also considers nutrition, metabolism, inflammation, oxidative balance, immune signaling and conventional oncology treatments.
INTERNAL LINKING STRATEGY
This page is designed to support other Sunridge cancer pages through internal linking.
Recommended internal links include:
That linking structure helps Google understand this page as a central Sunridge resource on quercetin, botanical oncology and pathway-based integrative cancer care.
FREQUENTLY ASKED QUESTIONS
Quercetin is a plant flavonoid found in onions, apples, capers, berries, citrus peel, tea and several medicinal plants. It has been studied for effects on inflammation, oxidative stress and cancer-related signaling pathways.
Quercetin has been studied because it can influence apoptosis, cell-cycle regulation, PI3K/AKT/mTOR signaling, NF-κB, STAT3, angiogenesis, invasion, migration and drug-resistance pathways in laboratory models.
Yes. Quercetin has been studied in cholangiocarcinoma cells, including research involving JAK/STAT suppression, ferroptosis, invasion and NF-κB signaling.
Yes. Quercetin has been studied in non-small cell lung cancer models, including research involving DNA-damage response, apoptosis and the SIRT5/PI3K/AKT pathway.
No. Quercetin has substantial preclinical research, but it has not been established as a stand-alone cancer treatment in large randomized human trials.
Quercetin has been studied in combination with several cancer therapies in preclinical models, but patients should not combine it with treatment without medical oversight because natural compounds may alter drug activity or toxicity.
Quercetin has limited solubility and variable absorption in many conventional oral forms. Formulation and delivery strategy may affect blood levels and biological activity.
Quercetin may be considered within individualized physician-directed integrative oncology programs when appropriate for the patient’s diagnosis, medications, laboratory findings and treatment plan.
BECOME A PATIENT
Quercetin is one of several natural compounds being studied for effects on cancer biology. At Sunridge Medical, these therapies are evaluated within the full clinical context of the patient’s diagnosis, medications, laboratory findings and current oncology treatment.
Speak with our Patient Care Team about your diagnosis, previous treatment and treatment goals.
RESEARCH
Browse 37 source-linked studies with the full title, publication year, research focus and a concise finding. Select any linked cancer type to move directly to its corresponding Sunridge page.
2024 · Treatment response
Interestingly, the synergistic effect was observed only when cells were pre-treated with MFA for 24 h before adding quercetin, not in the reverse order.
2022 · Metastasis and invasion
Multiple lines of evidence have shown that Quercetin has anti-tumor effects, documenting this natural compound exerts its pharmacological effects by targeting a variety of cellular and molecular processes, i.e., apoptosis, metastasis, and autophagy.
2021 · Apoptosis and cell death
Quercetin treatment significantly reduced cell viability in two GBM cell lines of U87MG and U373MG while keeping 85% of normal astrocytes alive.
2023 · Metastasis and invasion
Quercetin significantly suppressed the growth and migration of human GBM T98G cells, induced apoptosis, and arrested cells in the S-phase cell cycle.
2022 · Apoptosis and cell death
We found that quercetin administration inhibited GBM cell proliferation and promoted cell apoptosis in vitro.
2022 · Metastasis and invasion
Our results showed that quercetin markedly suppressed the viability of glioblastoma cells in vitro and in vivo, and significantly inhibited glioblastoma cell migration and invasion.
2024 · Tumor growth and proliferation
Therefore, we aimed to examine quercetin impacts on breast cancer cell proliferation and survival and the involvement of PI3K/Akt/mTOR pathway.
2023 · Cancer biology and response
Cervical cancer is emerging as a potential target of increased susceptibility to coronavirus disease-2019 (COVID-19), leading to compromised survival rates.
2023 · Cancer biology and response
The results from this study show that quercetin has the potential to prevent cervical cancer by regulating the expression of tumor-suppressive miRNAs.
2023 · Metastasis and invasion
The study reports eRRATUM: Quercetin Inhibits Intrahepatic Cholangiocarcinoma by Inducing Ferroptosis and Inhibiting Invasion via the NF-[Formula: see text]B Pathway.
2026 · Metastasis and invasion
Quercetin (QCT) and luteolin (LTL) are anticancer herbal compounds.
2023 · Treatment response
Furthermore, the incorporation of sulforaphane, recognized for its ability to scavenge glutathione, in combination with quercetin and oxaliplatin, substantially suppressed tumor growth in an HCT116 xenograft mouse model.
2021 · Metastasis and invasion
The migration distance and the number of invasive cells were significantly reduced in the 10 μg/mL quercetin group.
2024 · Cancer biology and response
Quercetin (QRC), a flavonoid present in various plants and foods, has demonstrated multiple health benefits, including anticancer properties.
2025 · Apoptosis and cell death
Quercetin significantly reduced the viability and proliferation of gastric cancer cells while promoting apoptosis, ER stress and ICD.
2026 · Metastasis and invasion
In vitro, quercetin dose-dependently inhibited cell proliferation, suppressed migration, and induced apoptosis through increasing Bax while decreasing Bcl-2 expression.
2008 · Apoptosis and cell death
It was concluded that the growth inhibition of quercetin was highly related to cell cycle arrest at the G(2)/M phase and induction of caspase-dependent apoptosis in human nasopharyngeal carcinoma HEN1 cells.
2025 · Cancer biology and response
Quercetin induced a Ca2+ response in HNSCC cells, which was significantly reduced by LF1 and YM.
2023 · Apoptosis and cell death
Quercetin has been reported to be a modulator of proliferation and survival in various types of cancers due to its cytotoxic effects.
2019 · Metastasis and invasion
showed that quercetin suppressed cell viability, migration, invasion and abundances of metalloproteinase-9 (MMP-9) and MMP-2 in oral cancer cells. miR-16 was down-regulated and reversed by addition of quercetin.
2013 · Apoptosis and cell death
Quercetin (Qu) is a principal flavonoid compound and an excellent free-radical-scavenging antioxidant that promotes apoptosis.
2014 · Apoptosis and cell death
Furthermore, in vivo administration of quercetin significantly reduced tumor volume in P39 xenografts and confirmed in vitro results regarding apoptosis, autophagy, and cell-cycle arrest.
2025 · Tumor growth and proliferation
Quercetin (Que) demonstrates broad antitumor effects by inhibiting glycolysis and cell proliferation.
2024 · Tumor growth and proliferation
In vivo, quercetin reduced VEGF secretion, impaired angiogenesis, slowed tumor growth, and decreased the number and proportion of VEGFR2-positive CTCs.
2024 · Metastasis and invasion
We explored whether quercetin could inhibit cell migration or invasion by transwell assay.
2021 · Apoptosis and cell death
Quercetin inhibited cell viability and induced mitochondria-dependent apoptosis in both A549 and H1299 cells in a dose-dependent.
2024 · Apoptosis and cell death
Moreover, our investigation indicates that quercetin significantly reduces the expression levels of ganglioside GD3 and its synthetic enzyme.
2023 · Metastasis and invasion
In addition, quercetin treatment induced apoptosis and inhibited migration and invasion.
2025 · Metastasis and invasion
In vitro experiments demonstrated that quercetin effectively inhibited the proliferation, apoptosis resistance, invasion, and migration of cisplatin-resistant EOC cells.
2025 · Apoptosis and cell death
Quercetin(QR) has been shown to inhibit the cell cycle and induce the apoptosis in various types of tumors.
2026 · Apoptosis and cell death
Quercetin inhibited cell proliferation and colony formation, triggered apoptosis, and promoted ferroptosis in A2780 and SKOV3 cells, marked by GPX4 downregulation and malondialdehyde levels increase.
2024 · Treatment response
This study investigated the synergistic effects of quercetin and paclitaxel on ovarian cancer.
2025 · Cancer biology and response
Quercetin (Que), a natural flavonoid, has the ability to inhibit tumor cell growth in a number of cancers; however, its poor water solubility and low bioavailability largely limit its application in cancer therapy.
2020 · Apoptosis and cell death
Utilizing PCa PCR array analysis with prevention tumor tissues, we identified that quercetin-resveratrol modulates genes involved in promoter methylation, cell cycle, apoptosis, fatty acid metabolism, transcription factors, androgen response, PI3K/AKT and PTEN signaling.
2026 · Cancer biology and response
Furthermore, we screened several anticancer compounds to determine their effects on S1PR1 expression levels in thyroid cancer cells and found that quercetin significantly reduced S1PR1 protein levels in these cells.
2025 · Cancer biology and response
Quercetin, a widely distributed natural flavonoid, has demonstrated potential therapeutic effects in managing both PCOS and EC.
2025 · Cancer biology and response
This study aimed to evaluate the anti-tumor effects of Quercetin by targeting CSCs and suppressing their stemness properties.
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