[Relationship between antibacterial activity of aloe and its anthaquinone compounds].Zhongguo Zhong Yao Za Zhi. 2003 Nov; 28(11):1034-7.ZZ
To investigate the relationship between the antibacterial activity of aloe and its contents of anthaquinone compounds, measure and compale antibacterial activities of aloin and aloe-emodin, and analyse the effect of glycoside on the antibacterial activity of aloin.
The antibacterial activities of the extracts from the outer leaf of Aloe saponaria Haw, aloin and aloe-emodin against three Gram-negative and two Gram-positive bacteria were investigated with the method of agar diffusion. The antibacterial effect of aloin on E. coli was further studied with scanning electron microscopy.
The antibacterial activities of aloe showed to be dependent on the dose of anthraquinone, aloin (1 g x L(-1)) exhibited higher antibacterial activity [inhibition diameter > (7. 1 +/- 0.15) mm] than Aloe-emodin (inhibition diameter < 5.0 mm), and aloin changed the morphology of E. coli and damaged the outer cell structrue.
Anthraquinone compounds are the active antibacterial components in aloe and aloin is the main active compound. The glycoside makes it easy for aloin to invade cells and enhances its activity.