Cistanche tubulosa (Schrenk) Wight Extract Ameliorates Learning and Spatial Memory Abilities in High-Altitude Hypobaric Hypoxia Rats.

Background

High-altitude hypobaric hypoxia (HH) is a major environmental stressor that impairs cognitive function, yet effective and widely available therapeutics remain limited. Although Rhodiola rosea has shown neuroprotective effects, its resource scarcity restricts large-scale application. Cistanche tubulosa (Schrenk) Wight, a traditional Chinese functional food, has been increasingly used in health supplements due to its anti-fatigue, anti-dementia, and memory-enhancing properties, suggesting potential benefits against hypoxia-induced cognitive impairment.

Objective

This study aimed to investigate the effects of C. tubulosa ethanol extract (CTE) on hippocampal tissue and gut microbiota upon chronic HH exposure using SPF male Sprague-Dawley (SD) rats.

Methods

A total of 60 male SD rats were randomly assigned to six experimental groups (n = 10 per group): normoxic control, untreated HH model, positive control (R. rosea), and low-, medium-, high-dose CTE treatment groups. Behavioral tests (Morris water maze), hippocampal histopathology, serum and hippocampal oxidative stress markers (SOD, GSH-Px, MDA), expression of PI3K/Akt/mTOR-HIF-1α signaling pathway proteins (by immunohistochemistry), and gut microbiota composition (by 16S rRNA sequencing) were evaluated.

Results

The results demonstrated that CTE significantly improved cognitive function, enhanced SOD and GSH activities, and reduced MDA levels in both hippocampus and serum. CTE also modulated the expression of PI3K/Akt/mTOR-HIF-1α pathway proteins in the hippocampus. Furthermore, CTE altered gut microbial diversity and abundance, increasing the proportion of beneficial bacteria, which may further influence hippocampal function via the gut-brain axis.

Conclusion

These findings provide scientific evidence for the application of C. tubulosa as a potential health supplement for high-altitude adaptation and lay a foundation for subsequent research.