Ashwagandha and cancer

Summary of ashwagandha

Promising potential:

Ashwagandha is an adaptogenic herb that has shown promising potential as a supplementary treatment during cancer journeys, especially regarding the management of side effects from treatment.

Primary effect:

Studies indicate that ashwagandha can have direct effects on cancer cells by promoting cell death and inhibiting growth, primarily through the bioactive substances known as withanolides [7].

Supportive role:

The herb’s most documented clinical benefits lie in improving quality of life, reducing fatigue and psychological stress, and counteracting bone loss, which is particularly relevant in connection with chemotherapy and anti-hormonal treatment (e.g., Tamoxifen) [1, 2, 4].

What is ashwagandha

Ashwagandha (Withania somnifera) is an adaptogenic herb (increases resistance to stress) that has been used in traditional Indian medicine (Ayurveda) for centuries. It is known for its stress-reducing, immune-boosting, and health-promoting properties. In recent years, ashwagandha has garnered interest for its potential as a supplementary treatment for cancer.

Mechanisms of action and potential of ashwagandha

Ashwagandha’s anticancer potential is attributed to a range of complex and interconnected mechanisms of action:

Induction of apoptosis and inhibition of cell proliferation

Ashwagandha contains bioactive compounds, primarily withaferin A and other substances known as withanolides, which have shown a direct cytotoxic effect on cancer cells [5].

Withaferin A

This withanolide binds to and inhibits proteins essential for cancer cell survival and growth, such as the proteasome (a cellular “trash disposal system”) and heat shock protein 90 (HSP90) (a protein that helps other proteins fold correctly) [6].

By inhibiting the proteasome, withaferin A prevents cancer cells from breaking down damaged or unnecessary proteins, leading to cell death. Inhibition of HSP90 destabilizes proteins necessary for cancer cell survival and growth, which can also lead to cell death.

Withanolides

This group of compounds can disrupt the cell cycle and prevent cancer cells from dividing uncontrollably. They can also activate caspases, a group of enzymes that play a central role in apoptosis.

Angiogenesis inhibition

Ashwagandha can inhibit the formation of new blood vessels that supply tumors (angiogenesis). Cancer cells need a constant supply of oxygen and nutrients to grow and spread. By inhibiting angiogenesis, ashwagandha can limit tumor growth and prevent metastasis (the spread of cancer to other parts of the body). Ashwagandha achieves this effect by inhibiting growth factors that stimulate the formation of new blood vessels, such as vascular endothelial growth factor (VEGF) [6].

Immunomodulation

Ashwagandha can strengthen the immune system by increasing the activity of natural killer (NK) cells and macrophages.

NK cells:

These cells are part of the innate immune system and can recognize and kill cancer cells without prior sensitization. Ashwagandha can increase the cytotoxic activity of NK cells, making them more effective at eliminating cancer cells.

Macrophages:

These cells are the “scavengers” of the immune system, engulfing and destroying pathogens, including cancer cells. Ashwagandha can increase macrophage phagocytosis activity (the ability to engulf and destroy, i.e., efficiency) and the production of cytokines (signaling molecules that regulate immune responses).

Antioxidant and anti-inflammatory activity

Ashwagandha possesses potent antioxidant and anti-inflammatory activity, which can protect cells from damage caused by free radicals and chronic inflammation.

Antioxidants

Ashwagandha contains a variety of antioxidants, including withanolides, flavonoids, and alkaloids, which can neutralize free radicals and prevent oxidative stress. Oxidative stress can damage DNA, proteins, and lipids in cells, contributing to cancer development.

Anti-inflammatory activity

Chronic inflammation is associated with an increased risk of cancer. Ashwagandha can inhibit the production of inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-$\alpha$) and interleukin-6 (IL-6), thereby reducing inflammation.

Epigenetic modulation

Ashwagandha can influence epigenetic mechanisms that regulate gene expression. Epigenetic changes can activate or deactivate genes without changing the DNA sequence. Ashwagandha can affect DNA methylation and histone modifications, two important epigenetic mechanisms that can influence cancer development.

Sensitization for chemotherapy

Ashwagandha can increase the sensitivity of cancer cells to chemotherapy. This can potentially improve treatment effectiveness and reduce the need for high doses of chemotherapeutic agents, which may decrease side effects. Ashwagandha can achieve this by modulating various signaling pathways in cancer cells involved in chemotherapy resistance.

Clinical trials

Several clinical trials have investigated ashwagandha’s potential as a supplementary treatment in cancer, often focusing on improving quality of life and managing side effects from conventional treatment:

Breast cancer and quality of life

A randomized, controlled trial showed that ashwagandha improved the quality of life and reduced fatigue in individuals with breast cancer receiving chemotherapy [4].

Head and neck cancer and radiation therapy

Another study indicated that ashwagandha reduced the side effects of radiation therapy in individuals with head and neck cancer.

Neuropsychological effects

Review articles highlight ashwagandha’s ability to reduce psychological stress and anxiety and improve sleep quality in individuals with a wide range of medical conditions, including cancer. Neuropsychological challenges are often a major issue during a cancer journey [2].

Specifically regarding Tamoxifen

Tamoxifen treatment is often associated with bone loss and symptoms related to mental health and sleep. Early research indicates that:
- Ashwagandha may have a protective effect against bone loss induced by estrogen deficiency, which is relevant for individuals undergoing hormonal therapy [1].
- In vitro studies have shown that ashwagandha does not interfere with Tamoxifen’s ability to inhibit the growth of breast cancer cells [3].

It is important to note that most clinical trials on ashwagandha and cancer have methodological limitations or are in early phases. Larger, randomized controlled trials are needed to confirm ashwagandha’s effectiveness and safety as a supplementary cancer treatment.

Safety

Ashwagandha is generally well-tolerated at recommended doses, but side effects such as diarrhea, stomach upset, and drowsiness may occur. In rare cases, liver problems have been reported, including severe liver failure.

Interactions with medication

Ashwagandha can interact with certain medications; therefore, it is necessary to discuss its use with a provider knowledgeable in the field.

Immunosuppressive agents: Since ashwagandha can strengthen the immune system (immunomodulation), it could potentially decrease the effectiveness of medications that suppress the immune system. This is particularly relevant during chemotherapy and radiation therapy.
Thyroid hormones: Ashwagandha can increase the body’s production of thyroid hormones. Individuals taking medication for an underactive thyroid (hypothyroidism) should be aware that ashwagandha may increase the effect of their medication.
Sedatives: Ashwagandha can enhance the effect of sedatives, including benzodiazepines and similar agents, due to its tendency to cause drowsiness.

Contraindications

Ashwagandha should be avoided by:

Pregnant women, as it may have abortifacient properties at high doses.
Individuals with autoimmune diseases (e.g., Lupus, rheumatoid arthritis), as ashwagandha can increase immune system activity.
Individuals with known liver disease until more knowledge is available.

Advantages of ashwagandha

Natural herb with a long history of medicinal use.
Multifunctional mechanism of action attacking cancer at various levels in the laboratory.
Can improve the quality of life for individuals in cancer treatment by reducing fatigue, anxiety, and sleep disturbances.
Potential synergistic effect with chemotherapy and radiation therapy.
Generally well-tolerated with few side effects at correct dosages.

Disadvantages and limitations

Limited clinical evidence for effectiveness in cancer.
Optimal dosage and administration form for cancer patients have not yet been fully established.
Can interact with certain medications, including immunosuppressive agents and thyroid medication.
Not suitable for everyone, including pregnant women and individuals with autoimmune disorders.

Dosage and application

Capsules/tablets

Contains powdered ashwagandha root or extract. Many quality products are standardized to specific concentrations of the herb’s active compounds. This means the manufacturer guarantees a specific, fixed percentage of the active substances in each capsule (e.g., 5%). This standardization is necessary to ensure consistency in the product’s strength and to be able to compare the dose with those used in clinical research.

Powder

Can be mixed into smoothies, juice, or water. Dosage may be more variable.

Liquid extract

Concentrated form, often mixed with alcohol or glycerin. Dosage by drops.

Tea

Brewed from ashwagandha root. Milder effect than other forms.

Conclusion

Ashwagandha is a promising natural herb with potential as a supplementary treatment for cancer. Its ability to inhibit cancer cell growth, strengthen the immune system, reduce inflammation, and improve the quality of life for cancer patients makes it an attractive supplement to conventional treatment.

However, more research is needed, especially human clinical trials, to confirm ashwagandha’s effectiveness and safety in cancer.

Always discuss complementary treatments such as supplements with your provider.

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