PMC

A. RBL2H3 mast cells were stimulated with the indicated concentration of kava extract in the absence or presence of 500nM PMA. Release of beta-hexoseaminidase was assayed after 30 min as described in Methods. Background release due to vehicle was subtracted from each reading. B. RBL2H3 mast cells were stimulated with the indicated concentrations (in μM) of Kavain (K), Methysticin (M) or dihydromethysticin (D). Release of beta-hexoseaminidase was assayed after 30 min as described in Methods. Background release due to vehicle (or PMA alone) was subtracted from each reading.

RBL2H3 mast cells were cultured in the presence or absence of the indicated kava extracts (1% w/v final concentration) for periods up to 14 days. Cells were sampled at 3 and 14 days and loaded with Fluo-4. Cells were stimulated with IgE/KLH-DNP in a standard sodium Ringer's solution containing 1mM CaCl₂.

Kavalactones at the indicated concentrations (μM) were added to Fluo-4 loaded mast cells in a standard sodium Ringer's solution containing 1mM CaCl₂. Baselines were established for 25s before addition of kava extract. Light grey bars show RFU at 10s prior to compound addition (basal intensity) and dark grey bars show RFU at 200s (final attained intensity of calcium response). Vehicle controls comprised equivalent volumes of DMSO (indicated in microliters) to those used in stimuli.

Kava powder was premixed with the mucilage of Hibiscus tiliaceus as described in Methods. Aqueous kava extracts at 0.5, 0.75. 1.0% and 2.5% (w/v) (with and without hibiscus mucilage pre-mix) were added to Fluo-4 loaded mast cells in a standard sodium Ringer's solution containing 1mM CaCl₂ (A,B,C) or made nominally calcium free (0mM CaCl₂ with 1mM EGTA, D, E, F). Baselines were established for 25s before addition of kava extract.

Aqueous kava extracts at 0.5, 0.75 and 1.0% (w/v) were added to Fluo-4 loaded mast cells in a standard sodium Ringer's solution containing 1mM CaCl₂ (A,B,C) or made nominally calcium free (0mM CaCl₂ with 1mM EGTA, E). Averaged response to vehicle is shown in D. Baselines were established for 25s before addition of kava extract. For comparison, response to 0.5μM ionomycin is shown in red. RFU, Relative Fluorescence Units.