title: Two functionally and chemically distinct immunomodulatory compounds in the gel of Aloe vera.
abstract: An aqueous extract of Aloe vera gel was analyzed guided by modulatory activity with regard to the in vitro activation of human complement and of human polymorphnuclear leucocytes (PMN). Upon ultrafiltration a high (h-Mr) and a low (l-Mr) molecular mass fraction were obtained. Pre-incubation of human pooled serum with the h-Mr fraction resulted in a depletion of classical and alternative pathway complement activity. In contrast, only the l-Mr fraction could inhibit the production of free oxygen radicals by activated PMNs. The latter activity cannot be attributed to non-specific effects like toxicity, interference with stimulant binding or scavenger activity.
authors.affiliation: Department of Chemical Pharmacy, Faculty of Pharmacy, State University of Utrecht, The Netherlands.
authors.forename: L A
authors.initials: LA
authors.lastname: Hart
authors.forename: P H
authors.initials: PH
authors.lastname: van Enckevort
authors.forename: H
authors.initials: H
authors.lastname: van Dijk
authors.forename: R
authors.initials: R
authors.lastname: Zaat
authors.forename: K T
authors.initials: KT
authors.lastname: de Silva
authors.forename: R P
authors.initials: RP
authors.lastname: Labadie
mesh_terms: D000276:Adjuvants, Immunologic / Q000302:isolation & purification* / Q000494:pharmacology; D000504:Aloe / Q000737:chemistry / Q000276:immunology*; D003169:Complement Inactivator Proteins / Q000302:isolation & purification; D005782:Gels; D006801:Humans; D066298:In Vitro Techniques; D009504:Neutrophils / Q000276:immunology / Q000378:metabolism; D010946:Plants, Medicinal / Q000276:immunology*; D013481:Superoxides / Q000378:metabolism; D014462:Ultrafiltration
chemical_list: D000276:Adjuvants, Immunologic; D003169:Complement Inactivator Proteins; D005782:Gels; D013481:Superoxides