Medical/biological study (experimental study)

Protective effect of procyanidins extracted from the lotus seedpod on immune function injury induced by extremely low frequency electromagnetic field. med./bio.

By: Zhang H, Cheng Y, Luo X, Duan Y

Published in: Biomed Pharmacother 2016; 82: 364-372

Aim of study (acc. to author)

The effects of exposure of mice to a 50 Hz magnetic field on the immune functions of the spleen and the protective effect of lotus seedpod procyanidins should be investigated.

Background/further details

Several studies showed that procyanidins have several biological functions, among others, they might enhance the function of the immune system.
Mice were divided into 5 groups (n=10 each): 1) exposure to the magnetic field and saline solution administration, 2) exposure to the magnetic field and administration of 30 mg/kg lotus seedpod procyanidins (LSPC) extract, 3) exposure to the magnetic field and administration of 60 mg/kg LSPC extract, 4) exposure to the magnetic field and administration of 90 mg/kg LSPC extract, 5) control group.

Endpoint

effects on the immune system: immune functions of the spleen

Exposure

- 50 Hz
- 50/60 Hz
- magnetic field
- co-exposure

Exposure	Parameters
Exposure 1: 50 Hz Exposure duration: 4 h/day for 28 days	magnetic flux density: 8 mT

Exposure 1

Main characteristics

Frequency	50 Hz
Type	magnetic field
Exposure duration	4 h/day for 28 days

Exposure setup

Exposure source	not specified
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	8 mT	-	-	-	-

Exposed system:

animal
mouse/ICR

Methods Endpoint/measurement parameters/methodology

molecular biosynthesis: protein expression of Bcl-2 and Bcl-xl (anti-apoptotic markers), Bax (pro-apoptotic marker) and caspases-3 and -9 (markers for apoptotic caspase-3 pathway) in spleen (Western blot)
cell viability/cell division/proliferation: early and late apoptosis of splenocytes (Annexin V-FITC/propidium iodide stain, flow cytometry), cell cycle analysis (propidium iodide stain, flow cytometry)
effects on the immune system: protein expression of cytokines in the spleen (INF-gamma, TNF-alpha, IL-2, IL-6 and IL-10; Western blot), DNA content in spleen (marker for DNA damage; reaction with diphenylamine, spectrophotometry), peripheral blood analysis (number of lymphocytes, leukocytes, erythrocytes and content of hemoglobin; method not mentioned)
morphol./histopathol. changes: organ indices (ratio of thymus/spleen/liver/kidney weight to body weight)

Investigated system:

isolated bio./chem. substance
DNA/RNA
intact cell/cell culture
isolated organ
spleen homogenates, blood

Investigated organ system:

immune system
thymus, spleen, liver, kidney, spleen homogenates

Time of investigation:

after exposure

Main outcome of study (acc. to author)

Exposure to the magnetic field (group 1) resulted in a significant reduction of relative weights of thymus, spleen and kidney compared to the control group. Mice with an additional administration of 90 mg/kg LSPCs (group 4), however, showed a significant increase of the organ weights compared to group 1.
The amounts of leukocytes, lymphocytes and hemoglobin were significantly reduced in group 1 compared to the control group, while they were significantly increased in group 4 compared to group 1.
The protein expressions of INF-gamma, IL-2, IL-6 and IL-10 were significantly reduced and the expression of TNF-alpha was significantly increased in group 1 compared to the control group. These effects were significantly reduced in groups 3 and 4.
The DNA content was significantly reduced in group 1 compared to the control group and it was significantly increased in group 4 compared to group 1.
The number of early and late apoptotic splenocytes was significantly reduced in group 1 compared to the control group and it was significantly increased in groups 3 and 4 compared to group 1.
In cell cycle analysis, group 1 had a significant larger G0 phase/G1 phase fraction and smaller S phase fraction compared to the control group. This effect was reduced by an additional LSPCs treatment (groups 2-4).
The magnetic field (group 1) significantly reduced Bcl-2 and Bcl-xl protein expression and significantly increased Bax, Caspase-3 and -9 levels. These effects were attenuated by LSPCs treatment and in group 4 there were significant differences in all expression levels compared to group 1.
The authors conclude that exposure of mice to a 50 Hz magnetic field might impair splenocytes via activation of Bax, caspases-3 and -9, and that lotus seedpod procyanidins could have a protective effect.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

National Natural Science Foundation (NSFC), China
The Priority Academic Program Development of Jiangsu Higher Education Institutions, China
Jiangsu Qing Lan Project, China
Jiangsu Six Talent Peaks Project, China

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