Propolis: Combating Exercise-Induced Fatigue and Enhancing Memory Function

Propolis, a traditional natural health product, has garnered significant research interest due to its rich composition of bioactive compounds. Existing studies confirm that propolis exhibits properties not only against exercise-induced fatigue but also holds potential for improving memory function. The physiological mechanisms behind these dual benefits involve multiple pathways, including alleviating oxidative stress, regulating energy metabolism, and exerting neuroprotective effects. This article systematically elucidates the biological mechanisms and application potential of propolis in these two domains based on current evidence.

I. Mechanisms of Propolis Against Exercise-Induced Fatigue: From Oxidative Stress to Energy Metabolism

Exercise-induced fatigue is a physiological state following intense or exhaustive physical activity, closely associated with oxidative stress. High-intensity exercise generates a surplus of free radicals. When their accumulation surpasses the body's antioxidant defense system, lipid peroxidation occurs, damaging cell membranes and mitochondrial integrity, ultimately leading to fatigue (Zhang, 2006). Therefore, enhancing the body's antioxidant capacity is considered a key strategy against exercise-induced fatigue.

Propolis is rich in flavonoids and phenolic acids, compounds known for potent free-radical scavenging activity and the ability to modulate intracellular antioxidant-related signaling pathways (Zhang et al., 2015). Multiple experimental studies demonstrate its significant anti-fatigue effects. For instance, Cao et al. (2004) found that propolis extract significantly prolonged the exhaustive swimming time of mice, scavenged free radicals, reduced oxidative damage caused by exhaustive exercise, and promoted post-exercise recovery of substance and energy metabolism. This suggests propolis alleviates fatigue not only through direct antioxidant action but also by enhancing recovery to improve exercise endurance.

Further research reveals propolis's specific cellular mechanisms. Pan et al. (2010) investigated the effects of propolis flavonoids on the myocardium of fatigued mice. Results showed propolis significantly reduced myocardial malondialdehyde (MDA, a lipid peroxidation marker) content and enhanced the activity of antioxidant enzymes (e.g., superoxide dismutase SOD, glutathione peroxidase GSH-Px) and ATPases (e.g., Ca²⁺-ATPase, Na⁺-K⁺-ATPase). These findings indicate that propolis improves myocardial oxidative status and energy metabolism efficiency, thereby extending time to exhaustion. Additionally, its cardiotonic effect—increasing cardiac output and improving myocardial ischemia and hypoxia during strenuous exercise—may also contribute to fatigue resistance (Wang et al., 1999).

Research by Yu et al. (2012) further supports these conclusions. They found propolis significantly reduced post-training erythrocyte deformity rates, myocardial and plasma MDA levels in mice, while increasing myocardial and plasma SOD activity, as well as myocardial GSH-Px, Ca²⁺-ATPase, and erythrocyte Na⁺-K⁺-ATPase activity. These data indicate propolis mitigates exercise-derived oxidative stress through multiple pathways, protecting cellular function and structural integrity.

In summary, the anti-exercise-fatigue effect of propolis is primarily attributed to its potent antioxidant properties and regulatory capacity on energy metabolism. These mechanisms not only help alleviate short-term fatigue but may also positively impact recovery and performance enhancement during long-term training.

II. Memory-Enhancing Effects of Propolis: Neuroprotection and Cognitive Enhancement

Learning and memory are advanced brain functions reliant on efficient information transmission between neurons. Factors like oxidative stress, neurotransmitter imbalance, or deficiency of essential elements can impair memory. The neuroprotective effects of propolis show significant potential in improving memory, likely related to its antioxidant, anti-apoptotic activities, and modulation of neurotransmitter systems.

Wang et al. (2008) studied the effects of propolis ethanol extract (EEP) on chemically-induced memory impairment in mice using a Y-maze test. EEP markedly improved learning and memory dysfunction caused by scopolamine, sodium nitrite, and aluminum chloride. The researchers hypothesized that the improvement in scopolamine-induced impairment might be related to enhanced central cholinergic system function, while improvements in sodium nitrite and aluminum chloride-induced impairments might be due to propolis's antioxidant action. This suggests a multi-target mechanism for memory protection.

Chen et al. (2008) further explored the mechanism of propolis water extract (WEP), finding it might alleviate scopolamine-induced learning and memory impairment in mice by inhibiting hippocampal acetylcholinesterase activity. Acetylcholine is a crucial neurotransmitter, and its levels are regulated by acetylcholinesterase. Thus, propolis may improve memory by maintaining acetylcholine levels and facilitating neuronal communication.

In vitro and in vivo experiments by Miyazaki et al. (2015) provide deeper evidence. Their study showed Brazilian propolis ethanol extract dose-dependently inhibited homocysteine-induced cell death in neuroblastoma SH-SY5Y cells and reactive oxygen species production in glioblastoma U-251MG cells. A water maze test further confirmed the extract improved cognitive dysfunction induced by high homocysteine, potentially associated with reduced amyloid aggregation in the brain. As amyloid aggregation is a hallmark of neurodegenerative diseases like Alzheimer's, propolis holds potential application value in preventing memory decline.

The memory-enhancing effects of propolis likely integrate antioxidant, anti-inflammatory, anti-apoptotic properties, and modulation of neurotransmitter systems. These mechanisms may help counteract memory impairment from external factors (e.g., chemicals) and potentially offer protection against age-related or disease-associated cognitive decline.

III. Dual Efficacy of Propolis: Integrated Perspective and Future Outlook

The roles of propolis in combating exercise-induced fatigue and improving memory are closely linked to its core antioxidant and anti-inflammatory properties. In the context of exercise, propolis helps the body manage oxidative stress and delay fatigue by scavenging free radicals, enhancing antioxidant enzyme activity, and optimizing energy metabolism. In neurocognition, propolis preserves memory function by protecting neurons, modulating neurotransmitters, and inhibiting pathological protein aggregation. This multi-functionality positions propolis as a natural health product with broad application prospects.

Reference:

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