Kuanxiong Aerosol Attenuates Ischemic Stroke Injury via Modulation of the TRPV1 Channel.

OBJECTIVE

To evaluate the therapeutic effects of Kuanxiong Aerosol (KXA) on ischemic stroke with reperfusion and elucidate the underlying pharmacological mechanisms.

METHODS

In vivo pharmacological effects on ischemic stroke with reperfusion was evaluated using the transient middle cerebral artery occlusion (t-MCAO) mice model. To evaluate short-term outcome, 30 mice were randomly divided into vehicle group (n=15) and KXA group (n=15). Mice in KXA and vehicle groups received 69 mg KXA and vehicle for 1 day, respectively. To evaluate long-term outcome, 35 mice were randomly divided into sham group (n=5), vehicle group (n=15), and KXA group (n=15). Mice in KXA and vehicle groups received 69 mg KXA and vehicle for 7 days, respectively. Pathological changes in the brain were observed by 2,3,5-triphenyltetrazolium chloride or Nissl stainings, and behavioral assessments, including the Modified Neurologic Severity Score, Bederson score, rotarod test, and adhesive removal test were conducted. The penetration ability of KXA and KX (KXA without propellants) through the blood-brain barrier was assessed both in vitro using a transwell model and in vivo. Furthermore, in vitro effects of KX (5, 10, and 20 µL/L) on oxygen and glucose deprivation/re-oxygenation (OGD/R)-induced injury, transient receptor potential vanilloid type 1 (TRPV1) modulation, calcium influx, and mitochondrial function were explored through Western blot, CCK-8 assay, JC-1 staining, calcium imaging, adenosine triphosphate (ATP) and antioxidant measurements.

RESULTS

In in vivo experiments, KXA reduced brain infarct volume and neuron loss in t-MCAO mice. Behavioral assessments showed marked improvement in the neurological deficit of t-MCAO mice with KXA treatment (P<0.05 or P<0.01). Additionally, in vitro findings indicated that KX ameliorated OGD/R-induced injury through TRPV1 channel modulation. KX increased cell viability in OGD/R-treated SH-SY5Y cells and prevented OGD/R-induced calcium overload by downregulating TRPV1 expression and constraining calcium influx through TRPV1 (P<0.05 or P<0.01). Furthermore, KXA maintained the membrane potential and function of mitochondria in OGD/R-treated SH-SY5Y cells.

CONCLUSIONS

KXA could attenuate ischemic stroke injury through TRPV1 channel modulation, indicating its potential as a promising therapeutic option for stroke in clinical practice.