In vitro activity: Aloe-emodin treatment led to the dissociation of heat shock protein 90 (HSP90) and ER α and increased ER α ubiquitination. Protein fractionation results suggest that aloe-emodin tended to induce cytosolic ER α degradation. Aloe-emodin, a natural compound found in aloe, inhibited both proliferation and anchorage-independent growth of PC3 cells. Protein content analysis suggested that activation of the downstream substrates of mTORC2, Akt and PKCα, was inhibited by aloe-emodin treatment. Pull-down assay and in vitro kinase assay results indicated that aloe-emodin could bind with mTORC2 in cells and inhibit its kinase activity. Of three anthraquinone derivatives, aloe-emodin, with a lower cytotoxicity showed concentration-dependently reducing virus-induced cytopathic effect and inhibiting replication of influenza A in MDCK cells. Galectin-3 also inhibited influenza A virus replication. Proteomic analysis of treated cells indicated galectin-3 up-regulation as one anti-influenza A virus action by aloe-emodin. Since galectin-3 exhibited cytokine-like regulatory actions via JAK/STAT pathways, aloe-emodin also restored NS1-inhibited STAT1-mediated antiviral responses in transfected cells: e.g., STAT1 phosphorylation of interferon (IFN) stimulation response element (ISRE)-driven promoter, RNA-dependent protein kinase (PKR) and 2'5',-oligoadenylate synthetase (2'5',-OAS) expression. AE downregulated mRNA expression and promoter/gelatinolytic activity of Matrix Metalloproteinase (MMP)-2/9, as well as the RhoB expression at gene and protein level. AE suppressed the nuclear translocation and DNA binding of NF-κB.

Evid Based Complement Alternat Med. 2013;2013:376123; Carcinogenesis. 2012 Jul;33(7):1406-11; Eur J Pharmacol. 2014 Sep 5;738:125-32.