Empower your white blood cells …

Green Tea Forestalls Inflammatory Diseases
… by enhancing leukocyte function

By Will Block

Figure 1. Leukocytes, or white blood cells, are the cells of the immune system and are divided into five types: the three phagocytes along with lymphocytes and basophils. Phagocytes protect the body by engulfing and ingesting harmful foreign bodies such as bacteria.
LEM1609Phagotysis274.jpg

White blood cells—also called leukocytes—are the cells of the immune system that protect the body against both infectious disease and foreign invaders. All leukocytes are produced and derived from multipotent cells in the bone marrow known as hematopoietic stem cells.

Leukocytes are found throughout the body, including the blood and lymphatic system. They also play a vital role in the host defense and inflammatory systems, the latter being responsible for the pathogenesis of a wide spectrum of acute and chronic diseases (see Fig. 1).

Epicatechins Are Anti-Inflammatory

Green tea is a popular beverage consumed the world over. Among its active ingredients are epicatechins, which possess antioxidant and distinct anti-inflammatory properties.

The purpose of a new study was to investigate if a green tea extract could enhance leukocyte function in humans.1 The cohort consisted of 10 males and 10 females between the ages of 20–55 (mean age: 35.2 ± 7.3) .Volunteers ingested 300 mg of the green tea extract daily for 14 days, and the capacity of circulating leukocytes to release both myeloperoxidase and lactoferrin was assessed.

Myeloperoxidase is most plentifully expressed in neutrophil granulocytes (a subtype of white blood cells). Lactoferrin is an iron-binding protein stored and secreted from neutrophils


The purpose of a new study was to
investigate if a green tea extract could
enhance leukocyte function in
humans.


In the study, whole blood from volunteers was stimulated with the bacterial peptide Formyl-Methionine-Leucine- Phenylalanine (fMet-Leu-Phe). Myelo­­peroxidase—an enzyme that converts hydrogen peroxide to hypochlorous acid and is stored in and secreted from the granules of neutrophils and monocytes—was measured along with lactoferrin. The antioxidant capacity of the blood of the volunteers was also determined using a method that measures the capacity of plasma to scavenge superoxide.

Antioxidant Status Increased

After 14 days of taking a green tea extract high in epicatechins, there was a significant increase in the release of myeloperoxidase and lactoferrin, and a significant increase in the total antioxidant status.


They also play a vital role in the host
defense and inflammatory systems.


Priming Human Neutrophils

In a previous report by the same researchers, the chemical constituents in green tea extract primed human neutrophils that were isolated from whole blood.2 In this study published 6 months earlier, a similar effect was found in twenty subjects who responded to the treatment, and yielded an increased release of both myeloperoxidase and lactoferrin when whole blood was stimulated by the addition of fMet-Leu-Phe.

Improving Immunological Response

This suggested that if these volunteers encountered a bacterial infection while taking the green tea extract supplements, they could improve their immunological response. The neutrophils in the supplemented volunteers would thus have responded more effectively to bacterial peptides, enhancing NADPH oxidase activity along with the enhanced release of myeloperoxidase inducing the formation of hypochlorous acid, which can kill gram-positive bacteria. The increased release of lactoferrin, which chelates iron, may also help to prevent the growth of bacterial species.


The chemical constituents in green
tea extract primed human
neutrophils.


Another study recently reported that (-)-epicatechin enhances the efficiency of myeloperoxidase in the presence of higher concentrations of hydrogen peroxide, which would enhance the immune response to bacterial infections.3

According to authors of papers #1 and #2, green tea extract would not significantly contribute to the inflammatory process, as priming of mature neutrophils in synovial fluid is a very efficient process. They conjecture it is the result of the presence of high levels of priming agents such as TNFα and IL-8, but not granulocyte/macrophage-colony stimulating factor (GM-CSF) in an inflamed joint.4


If these volunteers encountered a
bacterial infection while taking
the green tea extract supplements,
they could improve their
immunological response.


Their conclusion suggests that green tea extract can potentiate neutrophil function through priming. Stimulation of primed neutrophils by bacteria would enhance degranulation and superoxide production.

Paper #2 suggests that in vitro priming properties of the green tea extract were approximately 50% of GM-CSF. Unlike GM-CSF, the mechanism of green tea priming did not involve tyrosine kinase activation.


Green tea extract would not make
any significant contribution to the
inflammatory process, as priming of
mature neutrophils in synovial fluid is
a very efficient process.


Deterring Inflammatory Disease

Paper #1 indicates that a green tea extract when taken as a dietary supplement for just two weeks can increase the leukocyte activity and the total plasma antioxidant status and may have a role to play in the prevention of inflammatory disease.

References

  1. Lowe GM, Gana K, Rahman K. Dietary supplementation with green tea extract promotes enhanced human leukocyte activity. J Complement Integr Med. 2015 Dec;12(4):277-82.
  2. Gana K, Rahman K, Lowe GM. Immunomodulation of isolated human neutrophils by a green tea extract. J Nutraceut Funct Food Med Food. 2015 Jul;4:15–26.
  3. Flemmig J, Remmler J, Rohring F, Arnhold J. -)-Epicatechin regenerates the chlorinating activity of myeloperoxidase in vitro and in neutrophil granulocytes. J Inorg Biochem. 2014;130:84–91.
  4. El Benna J, Hayem G, Dang PMC, Fay M, Chollet-Martin S, Elbim C, et al. NADPH oxidase priming and p47phox phosphorylation in neutrophils from synovial fluid of patients with rheumatoid arthritis and spondylarthropathy. Inflammation. 2002;26:273–8.


Will Block is the publisher and editorial director of Life Enhancement magazine.

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