Fig. 1.

Bioactivity-guided extraction of RPA–RAM herb pair with inhibitory effect against NO production in LPS-stimulated RAW 264.7 macrophages. Cells were co-treated with PAEs at different concentrations ranging from 100 to 800 μg mL⁻¹ and LPS (1 µg mL⁻¹) for 24 h. a Picture of herb pair Radix Paeoniae Alba (RPA, Baishao) and Rhizoma Atractylodis Macrocephalae (RAM, Baizhu). b Concentration–response curves and IC₅₀ values of NO inhibition for PAEs. Data are expressed as mean ± S.D., n = 3