rhein

Rhein is a naturally occurring anthraquinone compound found in several medicinal plants such as *Rheum palmatum* (rhubarb), *Cassia tora*, *Polygonum multiflorum*, and *Aloe barbadensis*. It is a small molecule with diverse pharmacological activities including hepatoprotective, nephroprotective, anti-inflammatory, antioxidant, anticancer (antitumor), antidiabetic, antimicrobial and cardiocerebral protective effects[1][2][3][6]. Mechanistically, rhein acts through multiple cellular pathways such as inhibition of NF-kappaB signaling (reducing pro-inflammatory cytokines like interleukin‑1β and interleukin‑6), modulation of PI3K/Akt/MAPK pathways (including ERK1/2, JNK and p38 MAPK), induction of apoptosis via mitochondrial-mediated signaling and endoplasmic reticulum stress in cancer cells[2][3][6][8]. It also suppresses angiogenesis and extracellular matrix breakdown to prevent cancer cell invasion. Despite its promising bioactivities demonstrated in preclinical studies for conditions like inflammation-related diseases or diabetes mellitus type 2 models[5], clinical application is limited by poor water solubility and low bioavailability. Rhein can be an active metabolite of diacerein. Potential liver and kidney toxicity have been reported at higher doses[3].

Other names

4,5-dihydroxyanthraquinone-2-carboxylic acid1,8-dihydroxy-3-carboxyl-9,10-anthraquinoneDipropionyl RheinMonorheinRhubarb YellowRheic AcidCassic AcidChrysazin-3-carboxylic AcidChrysazin3-carboxylic AcidChrysazin 3-carboxylic Acid1,8-dihydroxyanthraquinone-3-carboxylic acid4,5-dihydroxyanthraquinone carboxylic acidRheinic Acid