Description
Aloin, extracted from natural sources, is a mixture of two diastereomers, termed aloin A (also called barbaloin) and aloin B (or isobarbaloin), which have similar chemical properties. Aloin is an anthraquinone glycosyl, meaning that its anthraquinone skeleton has been modified by the addition of a sugar molecule. Anthraquinones are a common family of naturally occurring yellow, orange, and red pigments of which many have cathartic properties, attributes shared by aloin. Aloin is related to aloe emodin, which lacks a sugar group but shares aloin's biological properties. Aloin inhibits the collagenase enzyme reversibly and non-competitively in Clostridium histolyticum, thereby increasing the number of fibroblast cells that the skin generates. Aloin reduces IL-6 and TNF-a expression as well as nitric oxide (NO) production and COX-2 and inducible NO synthase (iNOS) expression in LPS-stimulated RAW 264.7 cells when used at concentrations ranging from 100 to 400 mM.