Saikosaponin D is a triterpenoid saponin that has been found in Bupleurum roots and has diverse biological activities.1,2,3 It inhibits the proliferation of, and induces apoptosis in, SW1736, ARO, and 8305C anaplastic thyroid cancer cells when used at concentrations ranging from 5 to 20 μM.1 Saikosaponin D (5, 10, and 20 mg/kg) reduces tumor weight and volume in an ARO mouse xenograft model. It reverses reductions in gut microbial diversity, reduces colonic inflammatory cell infiltration, mucosal thickening, and goblet cell depletion, and increases colon length in a mouse model of ulcerative colitis induced by dextran sulfate .2 Saikosaponin D (1 mg/kg) decreases immobility time in the forced swim and tail suspension tests, as well as inhibits LPS-induced hippocampal microglial activation, in mice.3

1.Liu, R.-Y., and Li, J.-P.Saikosaponin-d inhibits proliferation of human undifferentiated thyroid carcinoma cells through induction of apoptosis and cell cycle arrestEur. Rev. Med. Pharmacol. Sci.18(17)2435-2443(2014) 2.Li, P., Wu, M., Xiong, W., et al.Saikosaponin-d ameliorates dextran sulfate sodium-induced colitis by suppressing NF-κB activation and modulating the gut microbiota in miceInt. Immunopharmacol.81106288(2020) 3.Su, J., Pan, Y.-W., Wang, S.-Q., et al.Saikosaponin-d attenuated lipopolysaccharide-induced depressive-like behaviors via inhibiting microglia activation and neuroinflammationInt. Immunopharmacol.80106181(2020)