Fig. 8: Stevioside attenuated S. pneumoniae pathogenicity in the G. mellonella infection model.
From: Stevioside curbs Streptococcus pneumoniae infection via inhibiting capsule biosynthesis
A Survival analysis of G. mellonella with different treatments. G. mellonella were challenged with 1 × 106 S. pneumoniae D39 and then treated with 50 mg/kg stevioside in a 5% DMSO containing vehicle or an equal volume of vehicle (10 μl) immediately after infection. The larvae in negative group were treated with PBS and vehicle, and larvae in stevioside group were treated with PBS and stevioside as described above. Survival was recorded at 6-hour intervals. The data were analyzed using the log-rank (Mantel‒Cox) test (n = 10 larvae each group). B Bacterial load in hemocoel of larvae (presented as CFU/ml). Larvae were sacrificed at 6 h postinfection, and the hemocoel was serially diluted and plated on THY agar to determine bacterial burden (n = 8 larvae each group). C The melanization assay of the hemocoel from G. mellonella infected and treated as described above. The hemocoels was collected at 6 h postinfection and analyzed by measuring the absorbance at OD490nm (n = 6 larvae each group). The data presented as the means ± SD were analyzed using an unpaired two-tailed Student’s t-test. *P < 0.05 and **P < 0.01 compared with the vehicle control group.
