Effects of curcumin on microbial diversity and transcriptomics in rats with spinal cord injury

Abstract:

[Background] Spinal cord injury, a severe trauma of the central nervous system, causes not only motor, sensory, and autonomic nerve dysfunction but also gastrointestinal dysfunction, being not conducive to subsequent functional recovery. Studies have shown that curcumin has a therapeutic effect on spinal cord injury, while little is known about whether curcumin can regulate intestinal microbiota after spinal cord injury or not and the treatment-related pathways. [Objective] To observe the effects of curcumin on the behaviors, the spinal cord histomorphology, the diversity and metabolites of cecal microbiota, and the spinal cord transcriptomics in the rats with spinal cord injury. [Methods] A total of 50 female SD rats of 6−8 weeks and 220−240 g were randomized into a sham operation group, a model (spinal cord injury) group, and low-, medium-, and high-dose (50, 100, and 200 mg/kg, respectively) curcumin+spinal cord injury groups. Curcumin 50 mg/kg, 100 mg/kg, and 200 mg/kg was intraperitoneally injected 30 min after the establishment of the rat model of spinal cord injury, once a day for a week. The Basso, Beattie & Bresnahan (BBB) locomotor rating scale was used for scoring of the motor function. Hematoxylin-eosin staining was used to observe the histomorphological changes in the spinal cord of rats. High-throughput sequencing of the V3+V4 variable region of 16S rRNA gene was carried out to analyze the α diversity, β diversity, and relative abundance of microflora, and the levels of short-chain fatty acids were measured, on the basis of which the changes of intestinal microbiota before and after treatment were evaluated. [Results] The medium dose (100 mg/kg) of curcumin significantly improved the limb motor function after spinal cord injury, demonstrating protective and repair effects on the damaged spinal cord. Curcumin administration in the rat model of spinal cord injury improved the diversity of microbiota and elevated the levels of short-chain fatty acids. The spinal cord injury altered the signaling pathways of intestinal microbiota, which was restored after the administration of curcumin. [Conclusion] Curcumin can affect intestinal microbial diversity and increase the levels of short-chain fatty acids in the rat model of spinal cord injury, and had a therapeutic effect on rats with spinal cord injury.