[Effect of aloe vera polysaccharide on the release of cytokines and nitric oxide in cultured human keratinocytes].

Objective: To investigate the effects of polysaccharide extracted from Aloe Barbadensis on the release of cytokines and nitric oxide (NO) in cultured human keratinocytes.

Methods: The levels of transforming growth factor-alpha (TGF-alpha), TGF-beta1, interleukin-1beta (IL-1beta), IL-6, IL-8, tumor necrosis factor (TNF) and NO in the supernatants of keratinocyte culture in which culture media containing 25, 50, 100, 200, 400 microg/ml, respectively of aloe polysaccharide were assayed. In the control group equal volume of media without the polysaccharide was used.

Results: Compared with control group, the levels of TGF-alpha, TGF-beta1, IL-1beta, IL-6, IL-8 and TNF in the supernatants of cultured keratinocytes were significantly higher when aloe polysaccharide was added (P<0.05 or P<0.01), and they were positively correlated to the concentration of aloe polysaccharide (P<0.01). However, aloe polysaccharide markedly decreased the level of NO in a dose dependent manner (P<0.01).

Conclusion: Aloe polysaccharide could promote keratinocytes to secrete TGF-alpha, TGF-beta1, IL-1beta, IL-6, IL-8 and TNF, and inhibit the release of NO.