Figure 1. Fractionation of Hyptis emoryi (H. emoryi) extract and the effect of the extract and its fractions on depolarization-evoked Ca²⁺ influx in DRG sensory neurons.

(A) Photograph of the plant, H. emoryi used in this study. (B) Fractionation of H. emoryi yielding fractions F1 and F2. (C) Differential interference contrast (DIC) and pseudocolored fluorescent images visualized for Fura2-AM in Dorsal Root Ganglia (DRG) neurons. Neurons were sequentially stimulated with 40 mM and 90 mM KCl for a period of 15 seconds following an initial 1-minute baseline measurement, and response was measured for 3 minutes after each challenge. Scale bar is 20 µm. Fluorescence scale indicates Fura-2AM ratio-metric fluorescence value (F₃₄₀/F₃₈₀). High values correspond to high intracellular [Ca²⁺] indicated in red. (D) Traces of response average of >300 neurons treated with H. emoryi extract (440 µg.ml−¹) or its fractions F1and F2 (88.4 µg.ml−¹). Arrows indicate the beginning of a 15-second stimulation period with 40 or 90 mM KCl as stated. (E) Peak calcium responses of sensory neurons incubated overnight with H. emoryi extract, derived fractions F1 and F2, and 0.1% DMSO (vehicle) in response to 40 and 90 mM KCl (n= 271–518 neurons). Responses were normalized to that of the vehicle and show average response ± S.E.M. Asterisks indicate statistical significance compared with cells treated with the vehicle (p<0.05, one-way ANOVA with Dunnett’s post-hoc test).