Fig. 1.

Effect of betulinic acid and betulin analogs on depolarization-evoked calcium influx in rat DRG sensory neurons. Peak calcium responses of female DRG sensory neurons incubated overnight with 0.1 % DMSO (vehicle) or 10 µM of BA analogs in response to 40-mM KCl. Betulinic acid (1) was used as a control (n = 33–365 neurons). The underlined compounds demonstrated more than 50 % inhibition in comparison to vehicle (0.1 % DMSO)- treated controls. Average responses were normalized to that of the vehicle and are shown as mean ± SEM. One-way ANOVA with Dunnett’s post-hoc test (see Table S1 for full statistics).