Embelin

Macrophages are a major component of inflammatory and tumor microenvironment. We previously reported that embelin suppresses colitis-associated tumorigenesis. Here, the role of macrophage targeting in the anti-inflammatory and anti-tumor properties of embelin was investigated. By using colitis-associated cancer (CAC) model, we demonstrated that embelin significantly depleted colon macrophages by blocking their recruitment. Moreover, embelin attenuated M2-like polarization of macrophages within the tumor microenvironment and eliminated their tumor-promoting functions during the development of CAC. Embelin potently inhibited NF-κB signaling in macrophages and decreased the production of key pro-inflammatory cytokines and tumorigenic factors involved in CAC, such as TNFα, IL-6 and COX-2. In addition, embelin directly reduced the polarization of M2 macrophages in vitro even in the presence of Th2 cytokines. These results suggested that targeting macrophages is, at least in part, responsible for the anti-tumor activity of embelin in CAC.

A series of dihydropyran embelin derivatives was synthesized through a direct and highly efficient approach based on a domino Knoevenagel intramolecular hetero-Diels-Alder reaction from natural embelin (1), using unsaturated aldehydes in the presence of organocatalysts such as ethylendiamine diacetate or l-proline. The aliphatic aldehydes yielded exclusively trans adducts, while mixtures of trans and cis isomers were found in reactions with aromatic aldehydes, with the cis form always predominating. Some of the compounds obtained were active and selective against Gram-positive bacteria, including multiresistant Staphylococcus aureus clinical isolates.

3-Nitropropionic acid (3-NP) causes severe neurotoxicity in animals, which depicts Huntington's disease (HD) in humans. Embelin, the main active constituent of Embelia ribes, has been reported to possess various pharmacological actions, mainly anti-inflammatory, antioxidant, anticonvulsant and neuroprotective. The aim of the present study was to evaluate the neuroprotective effect of embelin against 3-NP induced experimental HD in rats. Adult Wistar rats were pretreated with vehicle/embelin (10 and 20mg/kg p.o.) for 7 days. From 8th day onwards, embelin was co-treated with 3-NP (15mg/kg, i.p.) for 7 days. At the end of the treatment schedule, animals were evaluated for behavioral alterations and brain homogenates were used for estimation of oxidative stress parameters (lipid peroxidation, reduced glutathione, catalase and glutathione-S-transferase). 2,3,5-Triphenyl tetrazolium chloride (TTC) stained brain slices were used for lesion size measurement.

PURPOSE: To investigate effect of embelin on proliferation, apoptosis and gene expression profile changes in breast cancer cells.