Fig. 4: B38-CAP suppresses SARS-CoV-2-induced lung injury in hamsters.

a Experimental protocol; Hamsters were intratracheally infected (i.t.) with SARS-CoV-2 (1 × 10³ TCID₅₀), and then the hamsters were injected with B38-CAP (2 mg/kg i.p.) or vehicle once a day. Uninfected control hamsters treated with vehicle (n = 3 (b) or n = 6 (c–k)), SARS-CoV-2 infected hamsters (SARS2) treated with vehicle (n = 6) and SARS2 treated with B38-CAP (n = 6) (b–k). b % Changes of body weight at 4 days after infection from before infection. c qRT-PCR of virus N gene expression in the lungs of hamsters. d Angiotensin II levels in the lung tissues. e, f Lung edema measurements. Lung weight to body weight ratio (e) and wet to dry ratio of lung weight (f) are shown. g, h Lung histopathology. Representative images are shown (g). Bars indicate 1 mm (upper) and 100 μm (bottom). Lung injury scores were measured (h). i–k qRT-PCR analysis of pro-inflammatory cytokine expression in the lungs of hamsters; mRNA levels of IL-6 (i), TNF-α (j), and CXCL10 (k) normalized with β-actin. All values are means ± SEM. One-way ANOVA with Sidak’s multiple comparisons test. Numbers above square brackets show P values. Independent experiments were performed two times (b–k), and consistent results were obtained.