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

Molaei S et al. (2019): Effect of 50-Hz Magnetic Fields on Serum IL-1β and IL-23 and Expression of BLIMP-1, XBP-1, and IRF-4.
Mahaki H et al. (2019): The effects of extremely low-frequency electromagnetic fields on c-Maf, STAT6, and RORα expressions in spleen and thymus of rat.
Sobhanifard M et al. (2019): Effect of Extremely Low Frequency Electromagnetic Fields on Expression of T-bet and GATA-3 Genes and Serum Interferon-γ and Interleukin-4.
Wyszkowska J et al. (2018): Evaluation of the influence of in vivo exposure to extremely low-frequency magnetic fields on the plasma levels of pro-inflammatory cytokines in rats.
Mahdavinejad L et al. (2018): Extremely Low Frequency Electromagnetic Fields Decrease Serum Levels of Interleukin-17, Transforming Growth Factor-β and Downregulate Foxp3 Expression in the Spleen.
Li H et al. (2018): Eotaxin‑1 and MCP‑1 serve as circulating indicators in response to power frequency electromagnetic field exposure in mice.
Zhang H et al. (2017): Influence of extremely low frequency magnetic fields on Ca(2+) signaling and double messenger system in mice hippocampus and reversal function of procyanidins extracted from lotus seedpod.
Ding Z et al. (2017): Vitamin C and Vitamin E Protected B95-8 and Balb/c-3T3 Cells from Apoptosis Induced by Intermittent 50Hz ELF-EMF Radiation.
Luo X et al. (2016): Chemoprotective action of lotus seedpod procyanidins on oxidative stress in mice induced by extremely low-frequency electromagnetic field exposure.
Yin C et al. (2016): Neuroprotective effects of lotus seedpod procyanidins on extremely low frequency electromagnetic field-induced neurotoxicity in primary cultured hippocampal neurons.
Luo X et al. (2016): Occupational exposure to 50 Hz magnetic fields does not alter responses of inflammatory genes and activation of splenic lymphocytes in mice.
Li BL et al. (2015): Effect of long-term pulsed electromagnetic field exposure on hepatic and immunologic functions of rats.
Duan Y et al. (2014): Extremely low frequency electromagnetic field exposure causes cognitive impairment associated with alteration of the glutamate level, MAPK pathway activation and decreased CREB phosphorylation in mice hippocampus: reversal by procyanidins extracted from the lotus seedpod.
Duan Y et al. (2013): The Preventive Effect of Lotus Seedpod Procyanidins on Cognitive Impairment and Oxidative Damage Induced by Extremely Low Frequency Electromagnetic Field Exposure.
Salehi I et al. (2013): Exposure of rats to extremely low-frequency electromagnetic fields (ELF-EMF) alters cytokines production.
Cicekcibasi AE et al. (2008): Determination of the effects of extremely low frequency electromagnetic fields on the percentages of peripheral blood leukocytes and histology of lymphoid organs of the mouse.
Di Giampaolo L et al. (2006): Follow up study on the immune response to low frequency electromagnetic fields in men and women working in a museum.
Arafa HM et al. (2003): Immunomodulatory effects of L-carnitine and q10 in mouse spleen exposed to low-frequency high-intensity magnetic field.
Cabrales LB et al. (2001): ELF Magnetic Field Effects On Some Hematological And Biochemical Parameters Of Peripheral Blood In Mice.
Boscolo P et al. (2001): Effects of low frequency electromagnetic fields on expression of lymphocyte subsets and production of cytokines of men and women employed in a museum.
Häußler M et al. (1999): Exposure of rats to a 50-Hz, 100 µTesla magnetic field does not affect the ex vivo production of interleukins by activated T or B lymphocytes.
Mevissen M et al. (1998): Complex effects of long-term 50 Hz magnetic field exposure in vivo on immune functions in female Sprague-Dawley rats depend on duration of exposure.