Additional file 4: of Steroidal alkaloids and conessine from the medicinal plant Holarrhena antidysenterica restore antibiotic efficacy in a Galleria mellonella model of multidrug-resistant Pseudomonas aeruginosa infection

Effect of treatment with combinations of conessine and levofloxacin on survival of Galleria mellonella larvae infected with Pseudomonas aeruginosa PAM1033 (a) and PAM1626 (b). All larvae were inoculated with 2.5 × 103 cfu/mL P. aeruginosa and treated with each agent individually or in combination with three doses at 2, 4 and 6 h post-infection (indicated by the arrows). Treatments consisted of PBS, conessine (50 mg/kg), levofloxacin (0.05 or 5 mg/kg), and a combination of conessine with levofloxacin. Larvae were incubated at 37oC for 96 h and survival recorded every 24 h. * combination treatment group with significantly enhanced survival compared with any of the constituent monotherapies (P