Fig. 1

Chemical screen of plant derivatives identifies indigo as an inducer of anti-inflammatory cytokines, including IL-10 and IL-22, in HFD-induced immune cells and small bowel tissue explants. a, b Cytokine production, either IL-10 or TNF-α, in the VAT SVC of HFD mice treated with drug candidates or their vehicle (DMSO, EtOH, or water) for 3 days (IL-10: n = 4 experiments in indigo, wogonin, p-synephrine; n = 3 in other drugs pooled from 15 mice per experiment. TNF-α: n = 4 experiments in indigo, Aliso B acetate, gentiopicroside, perillaldehyde, phellodendrine, wedelolactone, bergapten, wogonoside, Ephedra sinica; n = 3 in other drugs pooled from 15 mice per experiment). Drug concentration: ephedrine is 10 μM; Indigo, gentiopicroside, peimine, perillaldehyde, phellodentrine, bergapten, picroside I, berberine and cinnamaldehyde 50 μM; Aliso B acetate, wedelolactone, baicalein, baicalin, wogonin, wogonoside, p-synephrine, 6-shogaol and 6-gingerol are 250 μM; Ephedra sinica is 1 μg/mL. Different bar colors represent indigo (blue), drugs decreasing IL-10 and TNFα (red), drugs decreasing IL-10 only (yellow), and drugs decreasing TNFα only (green). c IL-10 of cultured intestinal lamina propria immune cells supernatant after 72 h treated in vitro with 50 μM indigo and 0.05% DMSO under lipopolysaccharide (LPS) stimulation (n = 3/group, paired t test). d IL-22 in small bowel tissue explant culture supernatant of HFD-fed mice treated in vitro with 0.05% DMSO, 50 μM Indigo, 300 nM FICZ for 24 h (n = 10/group). Data in bar graphs represent mean ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001