Vitamin B2 (Riboflavin) May Slow Lymphoma Cell Growth

observational-study PMID: 31374832

Quick Summary: New research suggests Vitamin B2 (riboflavin), along with B6 and B9, may help slow the growth of lymphoma cells in a lab setting. This study showed promising results, but more research is needed to see if these vitamins can help people with lymphoma.

How Vitamin B2 Might Fight Cancer Cells

This study looked at how Vitamin B2 (riboflavin), Vitamin B6, and Vitamin B9 (folic acid) affected lymphoma cells in a lab. The researchers found that Vitamin B2 had several positive effects:

Reduced Cell Growth: Vitamin B2 helped slow down the growth of lymphoma cells by 45%.

Increased Cell Death: It also increased the death of cancer cells by over 2 times.

Reduced Cell Movement: Vitamin B2 decreased the ability of cancer cells to move around by 30%.

Impact on Immune Response: Vitamin B2 also affected a protein (PD-L1) that can help cancer cells hide from the immune system, potentially making the cancer cells easier to attack.

Reduced Inflammation: Vitamin B2 decreased the production of an inflammatory substance (IL-6), which can help cancer cells grow.

Study Details

Who was studied: Human lymphoma cells were grown in a lab.

How long: The cells were exposed to the vitamins for 24-72 hours.

What they took: The cells were treated with different amounts of Vitamin B2, B6, and B9. The highest dose of Vitamin B2 used was 100 µM (micromolar).

What This Means For You

This research is exciting, but it's important to understand what it doesn't mean:

It's early research: This study was done in a lab, not in people.

High doses were used: The amount of Vitamin B2 used in the study was much higher than what you'd get from food or a typical supplement.

Don't self-treat: This study doesn't mean that taking Vitamin B2 will cure or prevent cancer. Always talk to your doctor about cancer treatment.

Focus on a healthy diet: Make sure you get enough Vitamin B2 through a balanced diet. Good sources include milk, eggs, and meat.

Study Limitations

It's important to be aware of the study's limitations:

Lab setting: The results may not be the same in the human body.

High doses: The vitamin doses used were very high.

One type of cancer cell: The study only looked at one type of lymphoma cell.

No combinations tested: The study didn't look at how the vitamins work together.

More research needed: We need more studies to understand how Vitamin B2 affects cancer.

Key Findings

Vitamin B2 (riboflavin), B6 (pyridoxine), and B9 (folic acid) demonstrated anti-tumorigenic effects on U937 promonocytic lymphoma cells. Vitamin B2 (100 µM) reduced cell proliferation by 45% (p<0.001), increased apoptosis by 2.1-fold (p<0.01), and suppressed migration by 30% (p<0.05). It also downregulated programmed death ligand 1 (PD-L1) expression by 35% (p<0.05) and reduced pro-inflammatory cytokine IL-6 secretion by 30% (p<0.05). B6 and B9 showed similar but less pronounced effects.

Study Design

This in vitro observational study used human U937 promonocytic lymphoma cells. Researchers applied varying concentrations (25, 50, 100 µM) of each vitamin and measured outcomes over 24–72 hours. Methods included MTT assays for proliferation, wound-healing assays for migration, flow cytometry for apoptosis, ELISA for cytokines, and Western blotting for PD-L1 expression.

Dosage & Administration

Vitamins were administered directly to cell cultures at 25, 50, and 100 µM concentrations. Incubation periods ranged from 24 to 72 hours. The study tested each vitamin independently; no combination treatments were evaluated.

Results & Efficacy

Proliferation: B2 (100 µM) reduced cell growth by 45% (p<0.001), B6 by 30% (p<0.01), and B9 by 40% (p<0.001).
Apoptosis: B2 increased apoptosis by 2.1-fold (p<0.01), B6 by 1.5-fold (p<0.05), and B9 by 1.8-fold (p<0.01).
Migration: B2 suppressed migration by 30% (p<0.05), B6 by 20% (p<0.05), and B9 by 25% (p<0.05).
PD-L1: B2 reduced expression by 35% (p<0.05), suggesting immune checkpoint modulation.
Cytokines: B2 lowered IL-6 by 30% (p<0.05), indicating anti-inflammatory potential.

Limitations

In vitro model: Results may not reflect in vivo human biology.
High concentrations: Doses (up to 100 µM) exceed physiological levels achievable via supplementation.
Single-cell line: Findings limited to U937 cells; broader applicability untested.
No combination analysis: Synergistic effects of B vitamins were not assessed.
Mechanistic gaps: Molecular pathways (e.g., ROS generation, epigenetic changes) require deeper exploration.

Clinical Relevance

This study suggests riboflavin and other B vitamins may inhibit lymphoma cell growth through apoptosis induction, migration suppression, and PD-L1 downregulation. However, results are preliminary and derived from high-dose in vitro experiments. Supplement users should not interpret this as evidence for cancer prevention without further human trials. The findings support continued research into B vitamins as adjuncts in cancer therapy, but current data warrant caution in extrapolating efficacy or dosing to clinical settings. Maintaining adequate B vitamin intake via diet or standard supplementation remains important for general health, though targeted anti-tumor applications require rigorous in vivo validation.

Note: The study did not report human subject demographics, as it used cultured cell lines. All conclusions are specific to U937 cells and may not apply to other cancer types or physiological systems.