curcumin and alizarin

Topics: Animals; Anti-Bacterial Agents; Chitosan; Curcumin; Escherichia coli; Hydrogen-Ion Concentration; Pork Meat; Red Meat; Staphylococcus aureus; Swine; Zein

In vivo hydroxyl, peroxyl, and superoxide free radicals caused by oxidative stress can be toxic to molecules that are essential for the human body. However, there are natural compounds that can decrease the amount of these harmful species. In this work, we are focusing on two well-known compounds, alizarin (red) and curcumin, to study their interactions with these small radicals for a comparison between a rigid and a flexible structure. We made a mechanistic study and found the major and minor degradation products of curcumin as well as the autoxidation products of it based on a wide range of literature. We found several more favored pathways than those that were previously proposed. On the contrary, for degradation/oxidation of alizarin, only a few proposed mechanisms can be found which were performed in specific conditions. Our calculations predicted some favored rearrangements for the alizarin by peroxyl and superoxide radicals. Interaction of alizarin red and bright yellow curcumin with small radicals like hydroxyl, peroxyl, and superoxide radicals, such as the reaction between curcumin radicals and oxygen molecule, results in different species like epoxides or another kind of radical forms. The stability of epoxides is different in the case of rigid and flexible structures.

Topics: Anthraquinones; Computer Simulation; Curcumin; Free Radical Scavengers; Models, Chemical

Hamster flank organ growth, as measured by an increase in the area of the pigmented macule, is androgen-dependent. When flank organs of a castrated hamster are treated topically with testosterone, the flank organ becomes larger and darker. Since this growth is known to be dependent on the intracellular active androgen, 5alpha-dihydrotestosterone (DHT), inhibitors of 5alpha-reductase which converts testosterone to DHT can inhibit the growth of the flank organ. Certain unsaturated aliphatic fatty acids, such as gamma-linolenic acid and myristoleic acid, as well as other natural compounds, including alizarin and curcumin, are 5alpha-reductase inhibitors and inhibited flank organ growth. Green tea catechins, including (-)-epicatechin-3-gallate, and (-)-epigallo-catechin-3-gallate (EGCG) are also 5alpha-reductase inhibitors and inhibited flank organ growth. However, (-)-epicatechin and (-)-epigallocatechin, which are not 5alpha-reductase inhibitors, also inhibited flank organ growth. EGCG also inhibited DHT-dependent growth of flank organs. These catechins, therefore, may act by a mechanism other than inhibition of 5alpha-reductase. The effect of EGCG and other compounds was localized at the site of application; they did not affect the growth of the contralateral flank organ in the same animal. Since these compounds do not appear to exhibit systemic effects, they may be potentially useful for treatment of androgen-dependent skin disorders.

Topics: Administration, Topical; Androgens; Animals; Anthraquinones; Catechin; Cricetinae; Curcumin; Fatty Acids, Monounsaturated; Growth Inhibitors; Male; Mesocricetus; Orchiectomy; Sebaceous Glands; Testosterone