Rhein is a lipophilic anthraquinone extensively found in medicinal herbs, and has many pharmacological effects, including epatoprotective, nephroprotective, anti-inflammatory, antioxidant, anticancer, and antimicrobial activities. IC50 value:Target:In vitro: Rhein (0.1 and 1 mg/mL) evidently suppressed cell proliferation and mitogen-activated protein (MAP) kinase activation in human colon adenocarcinoma cells (Caco-2) but significantly lessened H2O2-induced DNA damage and the elevated MDA and ROS levels induced by H2O2/Fe2+ at the concentrations of 0.1–10 mg/mL [1].In vivo: Oral administration of rhein (150 mg/kg/d) evidently ameliorated renal interstitial fibrotic lesions and attenuated the expression of α-SMA and deposition of fibronectin (FN) in mice with renal interstitial fibrosis induced by unilateral ureteral obstruction. Rhein also suppressed TGF-β1 and its type I receptor expression in obstructed kidneys [1]. The biochemical parameters results of IgAN model rats showed that rhein-prevented and rhein-treated both improved the biochemical parameters and relieved renal pathological injury. The expressions of renal tissue TLR4, TGF-β1, but not TLR9 were significantly elevated in IgAN model rats (P< 0.05). Rhein-prevented and rhein-treated both inhibited TLR4 and TGF-β1 expressions [2].

References:
[1]. Xiaowen Chen, et al. Toll-like receptor 4 is involved in a protective effect of rhein on immunoglobulin A nephropathy. Indian J Pharmacol. 2015 Jan-Feb; 47(1): 27–33.
[2]. Hou ML, et al. The Drug-Drug Effects of Rhein on the Pharmacokinetics and Pharmacodynamics of Clozapine in Rat Brain Extracellular Fluid by In Vivo Microdialysis. J Pharmacol Exp Ther. 2015 Oct;355(1):125-34.
[3]. Yan-Xi Zhou, et al. Rhein: A Review of Pharmacological Activities. Evid Based Complement Alternat Med. 2015; 2015: 578107.