Fig. 4: Toxicity and in vivo efficacy of paenimicin.

a Schematic models illustrating the proposed mode of action of paenimicin for Gram-negative (above) and Gram-positive (below) bacteria. b Cytotoxicity assay of paenimicin against human hepatocellular carcinomas (HepG2) cell line, The experiments were repeated three independent times. Amphotericin B was used as a toxic control. Data are presented as means ± SD. c The pharmacokinetic curves of paenimicin and colistin over time after administration of 10 mg/kg via subcutaneous injection, (n = 3 rats per group). Data are presented as means ± SD. d In vivo nephrotoxicity assays of paenimicin and colistin. The concentrations of biomarkers (SPP1, TIMP-1, LCN2 and KIM-1) in mice serum were measured at 1 day and 7 days post administration of 40 mg/kg of paenimicin and colistin, respectively (s.c., qd, n = 3 mice per group). Significant differences were analyzed by one-way analysis of variance (ANOVA) (ns, no significance). e Neutropenic thigh infection model using drug resistant strains (n = 3 mice/ 6 thighs per group). All therapeutic compounds and vehicles were administrated via subcutaneous injection once daily and the bacteria burden were counted after 24 h post drug treatment. Significant differences were analyzed by one-way ANOVA, (ns, no significance). Data are presented as means ± SD. f Vaginitis infection model using N.gonorrehea ATCC 31426. All therapeutic compounds and vehicles were administrated via subcutaneous injection once daily for 3 consecutive days. On the day after the last administration, vaginal lavage fluid were collected and diluted for bacteria counting. Significant differences between each group with placebo were analyzed by one-way ANOVA. Data are presented as means ± SD. g Skin infection model using MRSA ATCC BAA44. Paenimicin and vancomycin were administrated via subcutaneous injection once daily for 5 consecutive days and the bacteria burden of wound tissues were counted 15 days after infection (n = 5 mice per group). Photographic records were taken. Significant differences were analyzed by one-way ANOVA. Data are presented as means ± SD.