Figure 3.

(A, B) Modulation of chloride currents through GABA_A receptors composed of α₁, β₂, and γ_2S subunits by 100 μM piperine and the indicated derivatives (dotted line indicates cutoff for highly active compounds). (C, D) Concentration-dependent I_GABA (EC_3–7) enhancement through α₁β₂γ_2S GABA_A receptors: (C) by 47 (■), 53 (▲), and 72 (●), ranked by efficiency, and (D) by 56 (▲) and 73 (●), ranked by potency, compared to piperine (dotted line). (E, F) Representative I_GABA modulated by (E) 72 and (F) 73. Data represent mean ± SEM from at least three oocytes and two oocyte batches. Asterisks indicate statistically significant differences from zero: *p < 0.05, **p < 0.01. Data for piperine were taken from ref (31).