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Medical/biological study (experimental study)

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.

Published in: Bioelectromagnetics 2017

Aim of study (acc. to author)

To examine the effects of 50 Hz magnetic fields on calcium ion signaling in the hippocampus of mice as well as the potential protective effect of procyanidins from lotus.
Background/further details: Procyanidins are phytochemicals, potentially having an anti-inflammatory and antioxidative effect and were extracted from lotus seedpod.
Male mice were divided into five groups (n=10 per group): 1) sham exposure + saline solution, 2) magnetic field exposure + saline solution, 3) magnetic field exposure + 30 mg procyanidins per kg bodyweight, 4) magnetic field exposure + 60 mg procyanidins per kg bodyweight and 5) magnetic field exposure + 90 mg procyanidins per kg bodyweight. Procyanidin solution and saline solution were administered orally and daily starting 15 days prior to magnetic field or sham exposure and continued during the four weeks of magnetic/sham exposure.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: 4 hours/day for 28 consecutive days
Exposure 1
Main characteristics
Frequency 50 Hz
Type
Exposure duration 4 hours/day for 28 consecutive days
Exposure setup
Exposure source
Chamber mice were exposed in a well ventilated Perspex box (14 cm x 10 cm x 12 cm (length, width, height)); box was placed in the middle of the coils
Setup a pair of Helmholtz coils was formed with 1.0 mm insulated wire (32 cm internal diameter, 36 cm external diameter, 3.5 cm width, 500 turns per coil); field was generated in a horizontal plane; coils were connected in parallel and fixed separately on the wall of a Perspex box that was filled with circulating water to cool the coils (maximum temperature with current was kept at 20 ± 2°C); magnetic field strength could be altered via voltage adjusting; magnetic field-generating device was placed in a temperature-controlled room (23 ± 2°C); there were no significant noise or vibration that could affect the mice
Sham exposure A sham exposure was conducted.
Additional info AC background magnetic field ~ 30 µT
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 8 mT - measured - ± 0.09 mT
Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated material:
Investigated organ system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Magnetic field exposed mice (group 2) showed significantly higher levels of PP2B, G protein, PKC beta II, PKA RIIb, and PKA C alpha compared to sham exposed mice (group 1), while the levels of BDNF, CaMK, and PKC alpha were significantly decreased. An administration of procyanidins (groups 3, 4, 5) resulted in an attenuation of the exposure related effects, often resulting in a non-significant difference between group 5 (exposure + 90 mg procyanidins per kg bodyweight) and the sham exposure (group 1).
Remark EMF-Portal: The mentioned Ca2+ increase in the abstract is taken from another publication Duan et al., 2014).
The authors suggest that exposure of mice to 50 Hz magnetic fields could influence Ca2+ signal pathways in the brain and that procyanidins extracted from lotus seedpods could attenuate the exposure induced effects.
Study character:

Study funded by

  • National Natural Science Foundation (NSFC), China
  • Jiangsu Key R&D Program, China
  • Jiangsu Qing Lan Project, China
  • Jiangsu Six Talent Peaks Project, China

Related articles

  • Yin C et al. (2016): Neuroprotective effects of lotus seedpod procyanidins on extremely low frequency electromagnetic field-induced neurotoxicity in primary cultured hippocampal neurons.
  • Zhang H et al. (2016): Protective effect of procyanidins extracted from the lotus seedpod on immune function injury induced by extremely low frequency electromagnetic field.
  • Luo X et al. (2016): Chemoprotective action of lotus seedpod procyanidins on oxidative stress in mice induced by extremely low-frequency electromagnetic field exposure.
  • 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.
  • Piacentini R et al. (2008): Extremely low-frequency electromagnetic fields promote in vitro neurogenesis via upregulation of Ca(v)1-channel activity.
  • Manikonda PK et al. (2007): Influence of extremely low frequency magnetic fields on Ca2+ signaling and NMDA receptor functions in rat hippocampus.