What are natural serotonin (5-hydroxytryptamine) blockers for cancer treatment?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: February 7, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

Natural serotonin blockers for cancer treatment are not well established, however, some options can be considered.

Available Options

  • Somatostatin analogs, such as octreotide acetate, are effective in controlling symptoms from carcinoid syndrome, which is caused by ectopic serotonin production in some patients with neuroendocrine tumors 1.
  • Serotonin receptor blockers are also used to control symptoms from carcinoid syndrome, although the specific natural blockers are not well defined in the provided evidence.

Context of Use

These options are typically used in the context of carcinoid syndrome, which is characterized by skin flushing, secretory diarrhea, and bronchoconstriction, and can be precipitated by chemotherapy, biopsy, anesthesia, surgery, or adrenergic drugs 1.

Important Considerations

  • The use of these options should be guided by the specific clinical context and the individual patient's needs, as the evidence is not strong enough to support a single, universal approach.
  • 5-HT3 serotonin receptor antagonists are commonly used to prevent nausea and vomiting in patients undergoing chemotherapy, but their role as natural serotonin blockers in cancer treatment is not well established 1.

From the Research

Natural Serotonin Blockers for Cancer Treatment

Some natural compounds have been identified as potential serotonin blockers for cancer treatment, including:

  • Selective antagonists of multiple serotonergic system pathway components required for serotonin biosynthesis, transport, activity via multiple 5-HT receptors (5-HTRs), and catabolism, which have been shown to reduce the viability of breast cancer stem cells 2
  • Inhibitors of serotonin release, such as octreotide, which is used in well-differentiated neuroendocrine cancers 3
  • Tryptophan hydroxylase (TPH) inhibitors, such as telotristat, which is currently being investigated in clinical trials to treat patients with metastatic neuroendocrine tumors and advanced cholangiocarcinoma 3
  • 5-HT receptor antagonists, which have been shown to have an anticancer effect in various cancers, including prostate cancer, breast cancer, urinary bladder, colorectal cancer, carcinoid, and small-cell lung cancer 3

Mechanism of Action

The mechanism of action of these natural serotonin blockers involves:

  • Blocking the serotonin-induced signaling pathways that promote tumor progression, such as the RhoA-ROCK1/2 signaling pathway 4
  • Inhibiting the expression of specific receptor subtypes associated with different fundamental stages of tumor progression, such as the 5-HT1 and 5-HT2 receptors 5
  • Reducing the levels of serotonin in the tumor, which has been shown to play a crucial role in cancer progression 6

Potential Therapeutic Targets

The serotonin pathway has been identified as a potential therapeutic target in cancer treatment, with several compounds being investigated for their anticancer effects, including:

  • Selective serotonin receptor antagonists
  • Inhibitors of serotonin release
  • Tryptophan hydroxylase (TPH) inhibitors
  • Compounds that reduce the levels of serotonin in the tumor 3

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

The Role of Serotonin in Breast Cancer Stem Cells.

Molecules (Basel, Switzerland), 2021

Research

Serotonin Pathway in Cancer.

International journal of molecular sciences, 2021

Research

Serotonin and cancer: what is the link?

Current molecular medicine, 2015

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.