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Modified Aloe barbadensis polysaccharide with immunoregulatory activity.
1Department of Drug Discovery and Screening, Univera Pharmaceuticals, Inc., Broomfield, CO, USA. jqiu@upi1.com
Planta Medica
|April 14, 2000
Summary
Modified Aloe polysaccharide (MAP) activates immune cells and promotes fibroblast growth, unlike native aloe. MAP also prevents UVB-induced immune suppression and inhibits tumor necrosis factor alpha release.
Area of Science:
- Biochemistry
- Immunology
- Dermatology
Background:
- Aloe barbadensis polysaccharides are known for various biological activities.
- The specific effects of modified Aloe polysaccharides on immune cells and UV radiation response require further investigation.
Purpose of the Study:
- To characterize a modified Aloe barbadensis polysaccharide (MAP) and evaluate its immunomodulatory and protective effects against UVB irradiation.
- To investigate the potential of MAP in preventing UV-induced immunosuppression.
Main Methods:
- Aloe barbadensis polysaccharide was modified using cellulase and purified through dialysis, ethanol precipitation, and size exclusion chromatography.
- Macrophage activation and fibroblast growth were assessed in vitro.
- Contact hypersensitivity (CHS) response in mice was used to evaluate in vivo immune suppression following UVB irradiation.
- Tumor necrosis factor alpha (TNF-alpha) release from human epidermoid carcinoma cells (KB cells) was measured after UVB exposure.
Main Results:
- Crude modified Aloe polysaccharide (MAP) demonstrated macrophage activation and stimulated fibroblast growth, while native Aloe barbadensis gel did not.
- MAP effectively prevented UVB irradiation-induced immune suppression in a mouse model, as indicated by the CHS response.
- MAP inhibited UVB-induced TNF-alpha release from KB cells, correlating with its in vivo protective activity.
- The characterized MAP had an average molecular weight of 80,000 Da and a specific sugar composition, suggesting a linear, acetylated structure.
Conclusions:
- Modified Aloe barbadensis polysaccharide (MAP) possesses significant immunomodulatory properties, including macrophage activation and fibroblast stimulation.
- MAP offers protection against UVB-induced immunosuppression and inflammatory responses.
- The findings suggest MAP's potential therapeutic applications in dermatology and immunology, particularly for managing UV-induced skin damage.