ABSTRACT
The active components of Aloe vera gel that can prevent ultraviolet B (UVB)-induced suppression of accessory cell function of Langerhans cells (LC) were purified by activity-guided sequential fractionation followed by in vitro functional assay. The functional assay was based on the fact that exposure of freshly isolated murine epidermal cells (EC) to UVB radiation resulted in impairment of accessory cell function of LC, as measured by their ability to support anti-CD3 monoclonal antibody (mAb)-primed T-cell mitogenesis. This UVB-suppressed LC accessory cell function was prevented by addition of partially purified Aloe gel components to cultures of UVB-irradiated EC. The Aloe gel components appeared to prevent events occurring within the first 24 h after UVB irradiation that lead to the impairment of accessory cell function. The Aloe gel components did not cause proliferation of anti-CD3 mAb-primed T-cells, nor did induce proliferation of normal EC. The activity-guided final purification of Aloe gel components resulted in the isolation of two components. Both of the components were small molecular weight (MW) substances with an apparent MW of less than 1,000 Da but different from each other in net charge characteristics at pH 7.4. These results suggest that Aloe vera gel contains at least two small molecular weight immunomodulators that may prevent UVB-induced immune suppression in the skin.
Subject(s)
Adjuvants, Immunologic/therapeutic use , Aloe/chemistry , Antigen-Presenting Cells/drug effects , Antigen-Presenting Cells/radiation effects , Langerhans Cells/drug effects , Langerhans Cells/radiation effects , Plant Extracts/therapeutic use , Plants, Medicinal , Radiation Injuries, Experimental/prevention & control , Ultraviolet Rays/adverse effects , Adjuvants, Immunologic/isolation & purification , Animals , Antigen-Presenting Cells/physiology , Gels , Langerhans Cells/immunology , Male , Mice , Mice, Inbred BALB C , Plant Extracts/isolation & purificationABSTRACT
Ether extracts of 1693 Chinese medicinal herbs and plants from 268 families were studied for the induction of Epstein-Barr viral (EBV) early antigen (EA) expression in the Raji cell line. Fifty-two from 18 families were found to have inducing activity. Twenty-five and seven of them were from Euphorbiaceae and Thymelaeaeeae, respectively. Some of them, such as Croton tiglium, Euphorbia kansui, Daphne genkwa, Wikstroemia chamaedaphne, Wikstroemia indica, Prunus mandshurica Koehne and Achyranthes bidentata are commonly used drugs. The significance of these herbs in the activation of EBV in vivo and their relation to the development of nasopharyngeal carcinoma were discussed.
Subject(s)
Antigens, Viral/biosynthesis , Drugs, Chinese Herbal/pharmacology , Herpesvirus 4, Human/metabolism , Antigens, Viral/drug effects , Cell Line , Herpesvirus 4, Human/drug effects , Herpesvirus 4, Human/immunologySubject(s)
Antigens, Viral/biosynthesis , Plants, Medicinal , Cells, Cultured , China , Humans , Plant Extracts/pharmacologyABSTRACT
Ether extracts of 495 Chinese medicinal herbs from 106 families were studied for Epstein-Barr virus (EBV) early antigen (EA) induction in the Raji cell system. 15 herbs from 10 families were found to have inducing activity. Water extracts of the same herbs also had inducing activity, but it was not as strong. The significance of these herbs in the activation of EBV in vivo and their relation to the development of nasopharyngeal carcinoma are discussed. No EA-inducing activity was found in 73 samples of 14 different foods tested.
