Fig. 4.

Intranasal delivery of wtAIDS peptide protects heart functions in a mouse model of COVID-19. Six-eight week old C57/BL6 mice (n = 9) of both sexes were treated intranasally with wtAIDS or mAIDS peptides (100 ng/mouse/d). After 10 min, mice were intoxicated with recombinant SARS-CoV-2 spike S1 (50 ng/mouse/d) via intranasal route. After 7d of treatment, the activation of NF-κB was checked in the heart by EMSA (a) followed by monitoring heart functions by non-invasive electrocardiography (ECG) using the PowerLab (ADInstruments) [b, chromatogram of control mice; c, chromatogram of spike S1-intoxicated mice; d, chromatogram of (spike S1 + wtAIDS)-treated mice; e, chromatogram of (spike S1 + mAIDS)-treated mice; f, heart rate; g, RR interval; h, JT interval; i, R amplitude; j, heart rate variability; k, QRS interval; l, QT interval]. m) Serum LDH was quantified using an assay kit from Sigma. Results are mean + SEM of nine mice per group. ^*p < 0.05; ^**p < 0.01; ^***p < 0.001; NS, not significant