Heat stress leads to increased free radical production, and endurance impairment, according to the Taiwanese researchers behind the new study. Caffeic acid phenethyl ester, a phenolic compound from propolis, may protect against these detrimental effects.
Findings published in the Journal of Food Science indicate that pre-treatment with the extract prior to cycling led to significant reductions in the detrimental effects of excessive exercise.
Jasson Chiang from the Graduate Institute of Sport Coaching Science at the Chinese Culture University in Taipei recruited 30 competitive cyclists. The researchers isolated peripheral blood mononuclear cells (MNC) from the participants in order to test whether a pre-treatment with the propolis extract (0, 1, 2, 4 micrograms per millilitre) affected the response to hyperthermia.
According to their findings, hyperthermia increased both the production of superoxide and decreased the cellular levels of the antioxidant glutathione. On incubation with the propolis extract the researchers noted a reversal or reduced hyperthermia-induced effects, including reduced cell death (necrosis), inhibition of the over-production of superoxide, and an attenuation of the depletion of glutathione. All of these effects were in a dose-dependent manner, added the researchers.
“By the ex vivo model system, it shows that caffeic acid phenethyl ester may enhance the hyperthermal tolerance of mononuclear cells in competitive cyclists via antioxidative effect,” wrote the researchers.
“The protective effect of caffeic acid phenethyl ester against hyperthermal stress in the other normal cells and tissues, such as skeletal muscle and myocardium needs to be further investigated,” they concluded.
It is reported that propolis contains about 180 different compounds and the waxy resin has previously been linked to improvements of general health, skin health, and oral health.
Source: Journal of Food SciencePublished online ahead of print, doi: 10.1111/j.1750-3841.2009.01199.x“Caffeic Acid Phenethyl Ester, an Antioxidant from Propolis, Protects Peripheral Blood Mononuclear Cells of Competitive Cyclists against Hyperthermal Stress”Authors: Y.-J. Chen, A.-C. Huang, H.-H. Chang, H.-F. Liao, C.-M. Jiang, L.-Y. Lai, J.-T. Chan, Y.-Y. Chen, J. Chiang