Relationship between antibacterial activity of aloe and its anthaquinone compounds / 中国中药杂志

ABSTRACT

<p><b>OBJECTIVE</b>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.</p><p><b>METHOD</b>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.</p><p><b>RESULT</b>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.</p><p><b>CONCLUSION</b>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.</p>