Mechanisms of Salidroside in the Brain: Neuroprotection, Anti-Fatigue, and Stress Response Modulation

Salidroside is a phenolic glycoside and one of the main bioactive compounds found in the adaptogenic herb Rhodiola rosea. Traditionally used in Tibetan, Chinese, and Scandinavian medicine to combat fatigue and improve resilience to environmental stressors, salidroside has gained increasing scientific attention for its effects on the central nervous system [1–4]. Experimental evidence suggests that salidroside exerts neuroprotective, anti-fatigue, and stress-buffering effects through coordinated actions on oxidative stress pathways, mitochondrial function, inflammation, apoptosis, neurotransmission, and neuroendocrine signaling [3].

An especially important feature of salidroside is its apparent ability to cross the blood-brain barrier, allowing direct interaction with neural tissue. Once in the brain, salidroside influences multiple signaling pathways associated with neuronal survival and energy metabolism, making it a promising candidate for research into neurodegenerative disease, cognitive dysfunction, and stress-related disorders [3]. In this article, we will explore the mechanisms of salidroside and how they relate to each of these areas.

The Neuroprotective Properties of Salidroside

Neuroprotection refers to mechanisms that preserve neuronal structure and function during conditions such as oxidative stress, ischemia, neuroinflammation, and neurodegeneration. Salidroside appears to act through several overlapping protective pathways.

Oxidative stress is a central contributor to neuronal aging and degeneration. Neurons are especially vulnerable to reactive oxygen species (ROS) because of their high metabolic demand and reliance on mitochondrial ATP production [5]. Salidroside has consistently demonstrated antioxidant effects in both cellular and animal models of neurological injury [1].

Mechanistically, salidroside activates antioxidant defense systems through pathways involving nuclear factor erythroid 2-related factor 2 (Nrf2) [6]. Nrf2 regulates transcription of antioxidant enzymes such as superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), and heme oxygenase-1 (HO-1). Activation of these systems reduces lipid peroxidation and oxidative damage to proteins and DNA [7].

In Parkinson’s disease models, salidroside reduced ROS accumulation and improved mitochondrial complex I activity through DJ-1/Nrf2 signaling. The preservation of dopaminergic neurons accompanied these changes and improved motor performance in experimental animals [8].

Mitochondrial dysfunction is a hallmark of neurodegenerative disorders and central fatigue. Here, salidroside appears to stabilize the mitochondrial membrane potential, reduce mitochondrial swelling, and preserve ATP synthesis under stress conditions [9].

Salidroside has also been linked to modulation of mitophagy through the PINK1-Parkin pathway, helping remove dysfunctional mitochondria before they trigger apoptotic signaling (cell death). This mechanism is particularly relevant in diseases such as Parkinson’s disease, where impaired mitochondrial quality control contributes to the loss of neurons [9].

Neuroinflammation contributes to neuronal dysfunction in stroke, traumatic brain injury, depression, and neurodegenerative disease. Activated microglia release inflammatory mediators including tumor necrosis factor-alpha (TNF-α), interleukin-1β, and nitric oxide, all of which can exacerbate neuronal injury. Salidroside suppresses inflammatory signaling by inhibiting pathways such as toll-like receptor 4 (TLR4)/NF-κB and the NLRP3 inflammasome [10,11].

How Does Salidroside Impact Brain Fatigue?

Central fatigue involves impaired neural drive, reduced cognitive performance, altered neurotransmitter balance, and diminished stress resilience. Salidroside’s anti-fatigue effects appear closely tied to its influence on mitochondrial energetics, neurotransmission, and stress hormone regulation [12].

Fatigue is strongly associated with impaired ATP availability and increased oxidative burden. Through AMPK and mitochondrial regulatory pathways, salidroside may improve neuronal energy efficiency and reduce metabolic strain during prolonged physical or mental stress [1,9].

Animal studies demonstrate that salidroside can increase glycogen storage, improve oxygen utilization, and reduce accumulation of fatigue-associated metabolites [13]. Although much of this literature focuses on skeletal muscle [14], the same metabolic principles likely contribute to improved brain endurance and cognitive resilience.

How Does Salidroside Modulate the Stress Response?

One of the most widely discussed properties of Rhodiola-derived compounds is adaptogenic activity — the ability to enhance resilience to physical and psychological stressors. Salidroside appears to influence stress adaptation through effects on the hypothalamic-pituitary-adrenal (HPA) axis and neuroendocrine signaling.

Chronic stress activates the HPA axis, increasing secretion of corticotropin-releasing hormone, adrenocorticotropic hormone, and cortisol. Persistent elevation of glucocorticoids can impair hippocampal function, suppress neurogenesis, and contribute to mood disorders. Salidroside appears to normalize HPA axis activity in stress models, reducing excessive glucocorticoid responses while improving behavioral markers of stress resilience [15,16]. This modulation may protect hippocampal neurons from stress-induced atrophy and help preserve cognitive function during chronic psychological strain.

Another mechanism underlying stress resilience may involve neurotrophic signaling. Salidroside has been shown to increase expression of brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), and neurotrophin-3 in experimental models [17–19]. BDNF is critically involved in synaptic plasticity, learning, memory, and emotional regulation. Reduced BDNF signaling is associated with depression and chronic stress exposure. By supporting neurotrophic pathways, salidroside may promote neuronal repair and adaptive plasticity.

Emerging evidence suggests salidroside may function as a hormetic compound [20]. Hormesis refers to a biological phenomenon in which mild cellular stress triggers adaptive protective responses that increase resilience to larger stressors later. Through mild activation of stress-response pathways such as Nrf2 and AMPK, salidroside may precondition cells to better tolerate oxidative, metabolic, or inflammatory insults [21]. This concept may partly explain its broad-spectrum protective effects across multiple organ systems.

Salidroside and Neurotransmitters 

In addition to its antioxidant and mitochondrial effects, salidroside may also influence several neurotransmitter systems involved in mood, motivation, cognition, and stress resilience [1]. Neurotransmitters such as dopamine, serotonin, norepinephrine, and acetylcholine play central roles in regulating mental energy, emotional state, attention, and behavioral responses to stress. Experimental evidence suggests that salidroside and Rhodiola rosea extracts containing salidroside can modulate monoaminergic signaling, potentially helping maintain neurotransmitter balance during periods of physical or psychological strain [22].

[22]       T. Zhu, H. Liu, S. Gao, N. Jiang, S. Chen, W. Xie, Effect of salidroside on neuroprotection and psychiatric sequelae during the COVID-19 pandemic: A review, Biomedicine & Pharmacotherapy 170 (2024) 115999. https://doi.org/10.1016/j.biopha.2023.115999.