Figure 6. BHB augments growth of R. oryzae and attenuates neutrophil functions.

(A) R. oryzae spores (5 × 10⁵/ml) were grown in RPMI-1640 without phenol red supplemented with 10 mM BHB, 26 mM NaHCO₃, or both, which resulted in modulation of the media pH. (B) Growth of R. oryzae was measured spectrophotometrically at 600 nm over time (n = 12 for each time point per each group). (C) R. oryzae spores (10⁵ per 10 μl) were plated on RPMI-1640 without phenol red supplemented with BHB or BHB + NaHCO₃ agar plates (n = 12 per arm), and the diameter of the colony was measured 24 hours after incubation at 37°C. (D) The effects of BHB or BHB + NaHCO₃ on human neutrophil inhibition of R. oryzae (1:10, effector/target ratio) were analyzed using XTT assay (n = 4 per arm). (E) The effects of BHB or BHB + NaHCO₃ on the ability of human neutrophils to produce ROS were analyzed using flow cytometry after addition of DHR123. *P < 0.015 vs. all other groups; **P < 0.001 vs. all other groups; ^‡P < 0.002 vs. all other groups; ^#P < 0.05 vs. the 2 other treatments.