The Effect of Date Pollen Extract/Testosterone and Resistance Training on Gene Expression and Synthesis Rate of Occludin and Cadherin Proteins of Blood-Spinal Cord Barrier in Male Rats

Changes in gene expression and protein expression of the spinal-blood barrier play an important role in the transmission and development of neuro-inflammatory responses. In order to increase the knowledge related to the role of environmental interventions affecting the tight junction and adhesive proteins of this barrier, this study investigated the effect of four weeks of resistance training and date pollen/testosterone extract on gene expression and protein expression of occludin and cadherin in male rats.

In an experimental design, 30 male Wistar rats randomly divided into 6 groups: Control; Resistance training; DPP extract; Testosterone; DPP extract+ resistance training; Testosterone+ resistance training. The amount of 100 mg/kg date pollen extract was fed to mice by gavage for 4 weeks. Also, synthetic testosterone with a dose of 2 mg/kg was used subcutaneously as a positive control. Resistance training consisted of a four-week increasing training period on a 50-step ladder with 8 to 12 repetitions per session. After the intervention, gene expression was measured by RT-PCR method and protein expression was measured by western blot method.

Four weeks of resistance training caused a significant increase in occludin gene expression (P=0.010) and cadherin (P=0.015); While it had no significant effect on the protein expression of occludin (P=0.404) and cadherin (P=0.647). Also, the gene expression level of two proteins increased significantly under the influence of date pollen extract and testosterone (P<0.05).On the other hand, the protein synthesis rate of occludin (P=0.016) and cadherin (P=0.012) was increased only in the group receiving synthetic testosterone. Despite the fact that the highest level of gene expression of two proteins was observed when the interventions were combined simultaneously, there was no statistically significant difference between their synergistic effects (P=0.059). However, the highest expression of occludin and cadherin protein occurred when resistance training was combined with testosterone supplementation (P<0.05).

The results of this study showed that DPP extract is superior to other interventions for increasing the gene expression of occludin and cadherin proteins of the blood-spinal barrier and testosterone for increasing the expression of these proteins. The combination of these interventions with the double promotion of the signaling process of gene and protein expression will maintain the integrity and reduce the permeability of the blood-spinal cord barrier in healthy male animal samples.