4β-Hydroxywithanolide E is a withanolide steroidal lactone that has been found in P. peruviana and has anti-inflammatory and anticancer activities.^1,2,3 It inhibits LPS-induced nitric oxide (NO) production in RAW 264.7 cells and TNF-α-induced NF-κB activity in HEK293 cells (IC50s = 0.32 and 0.04 μM, respectively).¹ 4β-Hydroxywithanolide E (5 μM) inhibits LPS-induced increases in inducible nitric oxide synthase (iNOS) and COX-2 levels and Akt and STAT1 phosphorylation in RAW 264.7 cells.² It inhibits Wnt signaling in HCT116 and SW480 colorectal cancer cells (IC50s = 1.85 and 2.67 μM, respectively).³ 4β-Hydroxywithanolide E inhibits the proliferation of HCT116, SW480, HT-29, and LoVo cells (IC50s = 0.24-0.51 μM). It halts the cell cycle at the G0/G1 phase in HCT116 and HT-29 cells and induces apoptosis in HCT116 and SW480 cells in a concentration-dependent manner. 4β-Hydroxywithanolide E (10 mg/kg per day for 14 days) reduces tumor growth in an HCT116 mouse xenograft model.