hyperforin and Stroke

Stroke survivors often experience social isolation, which can lead to post‑stroke depression (PSD) and post‑stroke anxiety (PSA) that can compromise neurogenesis and impede functional recovery following the stroke. The present study aimed to investigate the effects and mechanisms of post‑stroke social isolation‑mediated PSD and PSA on hippocampal neurogenesis and cognitive function. The effects of the natural antidepressant hyperforin on post‑stroke social isolation‑mediated PSD and PSA were also investigated. In the present study, a model of PSD and PSA using C57BL/6J male mice was successfully established using middle cerebral artery occlusion combined with post‑stroke isolated housing conditions. It was observed that PSD and PSA were more prominent in the isolated mice compared with the pair‑housed mice at 14 days post‑ischemia (dpi). Mice isolated 3 dpi exhibited decreased transforming growth factor‑β (TGF‑β) levels and impairment of hippocampal neurogenesis and memory function at 14 dpi. Intracerebroventricular administration of recombinant TGF‑β for 7 consecutive days, starting at 7 dpi, restored the reduced hippocampal neurogenesis and memory function induced by social isolation. Furthermore, intranasal administration of hyperforin for 7 consecutive days starting at 7 dpi improved PSD and PSA and promoted hippocampal neurogenesis and memory function in the isolated mice at 14 dpi. The inhibition of TGF‑β with a neutralizing antibody prevented the effects of hyperforin. In conclusion, the results revealed a previously uncharacterized role of hyperforin in improving post‑stroke social isolation‑induced exaggeration of PSD and PSA and, in turn, promoting hippocampal neurogenesis and cognitive function via TGF‑β.

Topics: Animals; Anxiety; Behavior, Animal; Brain Ischemia; Depression; Hippocampus; Male; Mice, Inbred C57BL; Neurogenesis; Phloroglucinol; Recombinant Proteins; Recovery of Function; Social Isolation; Stroke; Terpenes; Transforming Growth Factor beta

Hyperforin, the main active ingredient of the medicinal plant Hypericum perforatum, has been shown to be neuroprotective against acute ischemic stroke. However, the long-term actions of hyperforin on the post-stroke functional recovery and underlying mechanisms have not been investigated. C57BL/6 wild-type mice or interleukin (IL)-17A knock-out mice underwent middle cerebral artery occlusion (60min) followed by reperfusion for 28 days. Here, we found that delayed treatment with hyperforin significantly promoted functional recovery and increased IL-17A expression in the ischemic hemisphere at 28 days post-ischemia (dpi). IL-17A knock-out or anti-IL-17A monoclonal antibody (mAb) treatment significantly attenuated the promoting effects of hyperforin on functional recovery. After screening for neurotrophic factors, we revealed that blocking IL-17A significantly decreased, whereas recombinant mouse IL-17A (rIL-17A) treatment significantly increased vascular endothelial growth factor (VEGF) expression. Our data also showed that rIL-17A treatment significantly increased CD34 expression and promoted functional recovery at 28dpi, and the promoting effects were attenuated by VEGF neutralizing antibody treatment. Furthermore, hyperforin treatment significantly increased the expression of VEGF and CD34 in the ischemic hemisphere at 28dpi, and the effects were attenuated by blocking IL-17A. Furthermore, VEGF neutralizing antibody significantly attenuated the promoting role of hyperforin on the cerebral CD34 expression. Thus, our results suggest that, in addition to the acute neuroprotection when delivered immediately after ischemic stroke, hyperforin could also promote functional recovery when delivered in the later phases of stroke recovery. Our results also reveal a previously uncharacterized property of IL-17A/VEGF signaling-induced angiogenesis in hyperforin-mediated functional recovery.

Topics: Angiogenesis Inducing Agents; Animals; Brain Ischemia; Interleukin-17; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Phloroglucinol; Recovery of Function; Signal Transduction; Stroke; Terpenes; Vascular Endothelial Growth Factor A