Indole-3-pyruvic acid is an endogenous metabolite of tryptophan and intermediate in the biosynthesis of the major auxin hormone, indole-3-acetic acid , in plants.[1][2][3] Indole-3-pyruvic acid (50 and 250 &#181M) activates the aryl hydrocarbon receptor (AhR) in a reporter assay.[1] It reduces UVB-induced cytotoxicity and the levels of COX-2 in HaCaT keratinocytes.⁴Topical administration of indole-3-pyruvic acid (100 &#181mol) reduces the severity of UVB-induced damage in mouse skin. Dietary administration of indole-3-pyruvic acid (0.1%) reduces diarrhea, colonic inflammation, and the colonic expression ofIl1b,Ifng,Tnfa, andIl12bin a mouse model of T cell-mediated colitis.[1] It increases the time spent in the open arms of the elevated plus maze in mice when administered at a dose of 100 mg/kg.[2] It also reverses the anxiogenic effect of caffeine and 3-hydroxy kynurenine, but not pentylenetetrazole or phenylethylamine, in the elevated plus maze in mice.

Reference:
[1].Aoki, R., Aoki-Yoshida, A., Suzuki, C., et al.Indole-3-pyruvic acid, an aryl hydrocarbon receptor activator, suppresses experimental colitis in miceJ. Immunol.201(12)3683-3693(2018)
[2].Lapin, I.P., and Politi, V.Anxiolytic effect of indole-3-pyruvic acid (IPA) in micePharmacol. Res.28(2)129-134(1993)
[3].Mashiguchi, K., Tanaka, K., Sakai, T., et al.The main auxin biosynthesis pathway in ArabidopsisProc. Natl. Acad. Sci. USA108(45)18512-18517(2011)
[4].Aoki, R., Aoki-Yoshida, A., Suzuki, C., et al.Protective effect of indole-3-pyruvate against ultraviolet b-induced damage to cultured HaCaT keratinocytes and the skin of hairless micePLoS One9(5)e96804(2014)